IMEsnl ~!~ - CGSpace - CGIAR

,

Book of Abstracts & Programme

TkeKle "Competitiveness of Root Crops for Accelerating Africa's Economic Growth"

Sub·Themes

• African Root Crops Trade & Market Scenarios

• Policies favourable to competitiveness of RootCrops in Africa

• African Scenario on Prod uction and Utilisation of Root and Tu ber Crops

• Business and lnvestment Scenarios on competitiveness of Root Crops in A£rica

benchmarking Latin American, Asian & European Markets (Learning from Latin

American, Asian & European Industries)

• Mobilizing Investors for Sustainable Root & Tuber Crop Research and

Development.

Editors: R. U. Okechukwu,). A. Manu·Aduening, P. Ntawuruhunga, N. T. Dziedzoave,

E. Adu·Kwarteng and Michael Nerlinger Darko.

IMEsn l ~!~ CGIAR

MOFA

34

SCIENTIFIC THEMES POST HARVEST 57 - 131 Nutritional, Chemical and Sensory properties of ‘Pupuru’ subjected to fermentation of cassava

with selected species of Rhizopus and their combinations Adejuyitan, Johnson Akinwumi and Otunola, Ezekiel Tejumola

Microbiological assessment of dried mushroom in different packaging materials Ajayi, O.A., Obadina, A.O., Adegunwa, M.O., Sobukola, O.P., Adebowale, A.A., Omemu, A.

M., Asagbra, Y., Akinyemi Akinrinola, O. A., Asiru, W., Sanni, L.O. and Tomlin Keith

Functional and pasting properties of high quality cassava-tigernut composite flour Kareem, S.T., Adebowale, A.A., Sobukola, O.P., Obadina, O.A.,Kajihausa, O.E., Adegunwa, M.O., Sanni, L.O., Tomlins, K.

Effects of different processing methods on the nutrient composition and functional properties of

flour from false yam tuber (icacinao liviformis). Ariwaodo C.A and Ohuoba A.N

Evaluating the Potentials of wild Trifoliate yam (Dioscorea dumetorum) for increased Utilization in Nigeria.

Ezeocha V.C., Ojimelukwe, P.C., Onwuka, G.I Ameliorative potentials of cocoyam (Colocasia esculenta L.) and unripe plantain (Musa

paradisiaca L.) on renal and liver growths in Streptozotocin induced d iabetic rats Eleazu, C.O., Iroaganachi, M. and Eleazu K.C.

Processing of yellow-fleshed based cassava salad cream: carotenoid content optimization Chijioke, U. Udugwu, A. Oti, E and Ofoeze, M.A

Growth performance of broilers fed taro cocoyam (Colocasia esculenta) peels meal. Okereke, C.O. and Okereke, I.H.

Effects of sodium meta-bisulphite and blanching pretreatments on the quality characteristics of

yam bean (Pachyrhizus erosus) flour Buckman, E.S., Odurob, I. N, Plahara, W.A. and Carey, E.C

Some quality evaluation of fried snack from brewers’ spent cassava and wheat flour Omidiran, A. T., Sobukola, O.P., Sanni, S. A., Adebowale, A.A., Obadina, O.A.,Kajihausa, O.E.,

Adegunwa, M.O., Sanni, L.O., Tomlins, K, Wolfgang Tosch Process optimization for fufu production

M.U. Ukwuru and J.I. Awah

Comparative Economic Analysis of Fortified and Non Fortified Cassava Peel in Goat Feeding in Southwest Nigeria

35

Adetoye, A. M., Okojie, L. Adebayo, K. and Sanni. L. O.

Biologic and digestibility coefficient effect of including different levels of composite cassava meal in weaner rabbits diet

Ekwe, C.C.; Ukachukwu, S.N.; Odoemenam, V. and Ekwe, K.C. Quality attributes of gari produced from cassava substituted with cocoyam (Colocasia esculenta)

tuber Ade-Omowaye, B.I.O., Olatunde, S.T. and Akinwande, B.A.

Quality indices of cassava starch as affected by variety and maturity age Adegoke, Adekola and Adekoyeni, Oludare

Effect Of Different Packaging Materials And Storage Conditions On The Nutritional

Composition Of Dried Mushroom From Cassava Peels Ajayi, O.A., Obadina, A.O., Adegunwa, M.O., Sobukola, O.P., Adebowale, A.A., Omemu, A. M., Asagbra, Y., Akinyemi Akinrinola, O. A., Asiru, W., Sanni, L.O. and Tomlin Keith

Proximate and sensory evaluation of different cooking methods of edible aerial yam (dioscorea

bulbifera) Ofoeze M.A and Adeoye-Agomoh Q.C

Sensory evaluation and consumer acceptability of sweetpotato genotypes by youths in Omu Aran, Kwara state, Nigeria

Afolabi, M. S., Carey, E. E., Ogunjimi S . I, Akoroda, M. O. Nutritional Composition and Sensory Acceptability of Sausage Roll and Meat Pie from High

Quality Cassava Flour Akinlonu, E.O. and Sanni, S.A.

Recipes from low dry matter orange fleshed sweetpotato for Ghanaian households Eric Kuuna Dery, Eric Owusu Mensah, Sarah Afi Koryoe and Edward E. Carey

Design and performance evaluation of an agricultural waste-heated cabinet dryer for cassava

processing Alenkhe, B., Randriamorasata, J., Msangi, M., Ranaivoson, R., Andrianavalona, V., Kolawole, P. and Abass, A.

Pre-storage curing and Nanobiotechnology treatments on fresh yam (Dioscorea rotundata) tuber

in storage Eze, S. C., S. I Umeh., E. I. Eze., K. I. Ugwuoke, P. I. Ezeaku

Haematological and serum biochemical indices of japanese quails (Coturnix coturnix japonica) fed cassava grit as replacement for maize with or without β-glucanase

Amosun A.Y., Oyelami B. A., Abu O. A. and Tewe O.O

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Glycemic index and glycemic load values of three Ivorian mixed meal foods in healthy subjects Camille A. Kouame, Nestor K. Kouassi, Denis Y. N’dri, Georges G. Tiahou, Georges N. Amani

Assessment of the antioxidant potential of sweetpotato peel extract in controlling rancidity

Owusu-Ankomah, O., Oduro, I., Akwettey, W. Influence of the variety and cooking method on Glycemic Index of yam

Nestor Kouakou Kouassi, Georges Gnomblesson Tiahou and Georges N’Guessan Amani

Microbial and quality assessment of fresh mushroom (pleurotus ostreatus) from cassava peels Olotu I, O., Obadina, A.O., Adegunwa, M.O., Sobukola, O.P., Adebowale, A.A., Asagbra, Y., Akinyemi, Akinrinola, O. A., Asiru, W., Sanni, L.O. and Tomlin Keith

Retention of β-carotene in cream-fleshed sweetpotato-based complementary food stored in

different containers under simulated tropical temperature and humidity Francis Kweku Amagloh, Louise Brough, Janet L. Weber, Anthony N. Mutukumira, Allan Hardacre, Jane Coad

Performance of (Pleurotus pulmonarius) on Cassava (Manihot esculenta) peels and Cassava

Stalk Under Supplementation With Palm Kernel Cake (PKC) Agnes, E. Asagbra, Akinyemi-Akinrinola, O. A., Wahab. B. Asiru, Lateef, O Sanni, Gloria N Elemo, Anton Sonnenberg and Tomlins, I. Keith

Sensory evaluation and consumer acceptability of orange-fleshed sweetpotato by pregnant

women and children under years in Western Kenya Oyunga-Ogubi, M A, Cornelia Loechl, Hermann Quedraogo, and Jan Low

Effects of extrusion conditions on the functional properties of extruded snack from brewers spent cassava and wheat flour

Hamed, L.O., Sobukola, O.P., Obadina, O.A., Adebowale, A.A., Kajihausa, O.E., Adegunwa, M.O., Sanni, L.O., Tomlins, K, and Wolfgang Tosch

Comparative Value Addition for Improved RTB Entrepreneurship: A Case of OFSP in SSA – Nigeria, Tanzania and Mozambique

Frank Ojwang Functional properties and sensory quality of fermented cocoyam (Xanthosoma sagittifolium)

flour and its cooked paste Ayano, A.E., Idowu, M.A., Shittu, T.A.,Oguntonna, C. R. B

Performance evaluation of a chipping machine for cassava and yam chips Asiru, W. B; Adesina B. S; Ebun, K. K. and Onatoyinbo O.

Nutritive value of four cassava varieties and their effects in broilers rations

Tewe O. O., O.A. Abu, P. Kulakow and M. A. Mosobalaje

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The Effect of Chemical Preservatives on the Quality of Mushroom (Pleurotus Ostreatus) From Cassava Peels

Olotu I,O., Obadina, A.O., Adegunwa, M.O., Sobukola, O.P., Adebowale, A.A., Asagbra, Y., Akinyemi Akinrinola, O. A., Asiru, W., Sanni, L.O. and Tomlin Keith

Bibliographical synthesis to evaluate nutritive needs for meals for food products and yam bean consumed at the torque mother - child in Benin

J.G. Djidonou, Y.P. Adegbola, K. Hell, G.A. Mensah

Towards the development of sweetpotato-based couscous as human food in Benin Charlotte Fifamè KPOMASSE, Sègla Wilfrid Padonou, Jean Louis Ahounou

Application of Near Infra-Red Reflectance Spectroscopy (NIRS) for screening of fresh cassava (Manihot esculenta) genotypes for high concentrations of Provitamin A carotenoids

Oladeji Emmanuel Alamu, Bussie Maziya-Dixon, Thomas zum Felde, Peter Kulakow and Elizabeth Parkes

Preliminary investigation of the effect of granulation on the quality characteristics of instant pounded yam flour

Asiru, W.B., Kosoko, S.B., Owolabi, S.O., Adegbite, A and Elemo, G.N. Contribution of infant flour enriched with OFSP to improving the nutritional and immune status

of young children moderately malnourished in the medical district of Saint-Camille, Ouagadougou.

Toe Oumar, Mouhoussine Nacro, Jacques Simpore, Hema Adama, Gnoula Charlemagne, Blaise Sondo, Somda Jean Celestin, Tanoh/BrouAdjo Marie and Laeticia Ouedraogo

A comparative study of frying, organoleptic and textural characteristics of white yam (Dioscorea rotundata) and water yam (Dioscorea alata) chips for food uses

Oluwole, O.B, Asiru, W.B, Jegede A, Alagbe, G and Elemo, G.N Determining the effects of storage duration on the cooking qualities of cocoyam (Colocasia

esculenta) Ezeaku, P.I., UgwokeK.I. and Eze, S.C.

Some alternative energy sources [cassava (manihot esculenta), sweet potato (ipomea batatas), and cocoyam (xanthosoma sagittifolium schott.)] for poultry and piggery production and it’s

implications for food security Chidimma L. Obi, Chika E. Oyeagu,Augustine O. Ani, Petrus E. Nwakpu, Scholastica N.

Okongwu, Patience N. Onu, Ugochukwu S. Ekwu, Murphy B. Enwezor Assessment of the organoleptic qualities of composite cassava–cowpea “Gbodor”

M. S. E. Williams and N.M Anthony

Effect of variety and processing methods on the functional and pasting properties of high quality yam flour (HQYF)

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Wahab, B.A., Sobukola, O.P., Adebowale, A.A., Obadina, O.A., Kajihausa, O. E., Adegunwa, M.O., Sanni, L.O., Tomlins, K.

Keeping quality of unfermented wet cassava cake

Buliyaminu A. Alimi, Adejoke F. Bello, Ololade Abraham, Taofik A. Shittu, Lateef O. Sanni Exploiting Orange-fleshed sweetpotato for better nutrition and income

Mariama Fofanah

Production and appreciation of gari enriched with Yam bean (Pachyrhizus-spp) by processors in South and Central Benin Paul. Houssou Sègla. Wilfrid Padonou, Patrice. Y. Adegbola, Jean Louis Ahounou, Denis Olou,

Hermine Y. A. Djivoh, Pascal Fandohan, Prof. Guy. Apollinaire. Mensah

Feeding of grasscutters (Thryonomys swinderianus) of breeding with the diets of dolic tuberous (Pachyrhisus erosus) in Benin Pomalegni S. C. B., Anato M. M. A., Adegbola P. Y, Guedou M.S.E, Mensahs. E. P, Dahouda

M., Fandohan P. and Mensah G. A.

The use of the low dry matter yam bean Pachyrhizus erosus storage roots in drinks processing in Benin Sègla Wilfrid Padonou, Jean Louis Ahounou, Patrice Y. Adegbola, Agossou Hounyèvou Klotoe,

Adolphe Adjanohoun, Kouessi Aihou, Pascal Fandohan, Guy Apollinaire Mensah

Chemical Composition and the Effect of Processing on the Phytochemical content of Cocoyam (Xanthosoma maffa (Scoth)) tuber. Ukom, A.N, Ojimelukwe, P.C, Ezeama, C.F, Ortiz, D.A, and Aragon, I.J

A multivariate analysis of the relationship between quality of sweetpotato flour (‘elubo’) and

sensory properties of paste (‘amala’) Fetuga, G. O., Tomlins, K. I., Henshaw, F. O. and Idowu, M. A.

Effect of agroecology variability on dry matter, cyanogenic potential (cnp) and chemical composition of 0 cassava clones.

O.O. Etukudo, L.A. Babatola and B. Maziya – Dixon Descriptive sensory analysis and consumer acceptability of a cooked paste (‘amala’) from

sweetpotato. Fetuga, G. O, Tomlins, K. I., Henshaw, F. O. and Idowu, M. A.

Development and sensory evaluation of akara from sweetpotato flours (a local, cheap, Sierra Leonean snacks)

N.M Anthony, M. S. E. Williams

Effect of processing parameters on some quality attributes of yam starch and gluten based expanded fried snack

39

Akegbejo-Samsons, T., Sobukola, O.P., Henshaw, F.O., Afolabi, W.A.O. and Sanni, L.O.

Physicochemical Properties and Baking Qualities of Baked Wheat Products Supplemented with Pigeon Pea and Cassava Flours

S. Chilungo, P. Ng, M.Bennink and L.Bourquin Growth performance and cost benefit of growing pigs fed cassava peel Meal-Based Diets

Supplemented with Allzyme® SSF Adeyemi, O. M., Irekhore O. T., Idowu, O. M. O. and Akinola, O. S.

Effect of storage temperature and time on the functional properties of high quality water yam flour

Owo, H.O., Adebowale, A.A., Sobukola, O.P., Obadina, O.A.,Kajihausa, O.E., Adegunwa, M.O., Sanni, L.O., Tomlins, K.

Applications of experimental auction mechanisms and sensory evaluation methods to understand consumer acceptance of biofortified yellow cassava in Nigeria

Adewale Oparinde, Abhijit Banerji and Ekin Birol

Physical and sensory properties of extruded snacks from high quality cassava - tigernut composite flour Kareem, S.T., Sobukola, O.P., Adebowale, A.A., Obadina, O.A.,Kajihausa, O.E., Adegunwa,

M.O., Sanni, L.O., Tomlins, K.

Physical and functional properties of fermented cassava flour (lafun) obtained from different markets in Southwest Nigeria Adebayo-Oyetoro, A. O., Oyewole, O. B., Obadina, A.O. and Omemu O.M

Functional and pasting properties of wheat–brewers’ spent cassava flour blends

Omidiran, A. T., Sobukola, O.P., Sanni, S. A. Adebowale, A.A., Obadina, O.A.,Kajihausa, O.E., Adegunwa, M.O., Sanni, L.O., Tomlins, K, Wolfgang Tosch

Nutritional composition and diversification of the use of D. rotundata varieties in Fako Division of Cameroon.

Achidi Aduni Ufuan, Ikome Evelyn Mesaka, Forba Josepha Tendoh and Dopgima Levai Quality indices of cassava starch as affected by variety and maturity age

Adegoke, Adekola and Adekoyeni, Oludare

Pasting properties of flours from high-dry matter sweetpotato (ipomoea batatas l.) varieties: the influence of crop maturity Adu-Kwarteng, E., Esther Sakyi-Dawson, Fred F. Shih, Kim Daigle and Van-Den Truong

Proximate composition and sensory evaluation of prawn crackers made from sweetpotato

(Ipomoea batatas) starch Kajihausa O. E. and Esenwa J. O

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Nutritive value of four cassava varieties and their effects in brioler rations

Tewe O. O., O.A. Abu, I. Andrew, P. Iluebbey, and M. A. Mosobalaje, P. Kulakow

Microbial Hazard and Hazard Analysis Critical Control Points in “Gari” Production System M.O. Ekop and O.E.Ekop

Analysis of opportunities for improving the efficiency of Ghanaian cassava processing industries through introduction of selected Indian technologies.

J.Thajudhin Sheriff, Nanam Tay Dziedzoave, Benjamin Addi Okae, Keith Tomlins Effect of variety and processing methods on the antinutritional and vitamin contents of high

quality yam flour (HQYF) Wahab, B.A., Adebowale, A.A., Sobukola, O.P., Obadina, O.A.,Kajihausa, O.E., Adegunwa,

M.O., Sanni, L.O., Tomlins, K. Cassava whey- a potential source of Citric Acid

Kareem S.O, Oladipupo I. O., Omemu, A. M. and Babajide J. M.

Food Safety Level Assessment in Cassava Tubers Processing into “Gari”. Ekop M.O., Ekop O.E

AGRONOMY 132 - 194 Evaluation of different animal manures as plant nutrient sources on the production of cocoyam (colocasia esculenta) in inland valleys of Southeastern Nigeria

Nwite, John C., Okolo, C. Chukwuebuka, Igwe, Charles A., Ezeaku, Peter I., Chukwudi, P. Uchechukwu., Nwite, James N., Okenmuo, Frances C., Agbo, Emmanuel A. and

Umeugochukwu, Obiageli P. Effects of nitrogen sources on soil carbon sequestration in Southeastern Nigeria

N.R.,Njoku, O.A. Opara – Nadi and O. Eke- Okoro

Yield and P use efficiency of two cassava genotypes under different P levels in a derived savanna of South West Nigeria V.O. Aduramigba-Modupe, A.O. Aduramigba-Modupe and S. Olanipekun

Effects of slope position, urban refuse compost and sewage sludge on soil properties and cassava

yield in South Eastern Nigeria Ezema Raymond A, Obi M.E, Asadu C.L.A.

Yam minisett intercropping studies for improved productivity of the cropping systems and soil fertility enhancement

ANO, A. O., ADIELE, J., CHUKWU, L. I. and Nwosu, P. O.

41

Effect of weeding regime on the growth and yield of Hausa potato on ultisols of South Eastern Nigeria.

Njoku S.C, A. O. Olojede, D. U. N. Ikeogu, and C.Obasi

Yield responses of sweetpotato (ipomoea batatas) and soyabean (glycine max) intercrop to nitrogen levels in south eastern Nigeria. Obasi C.P, I.I.M Nwankwo, T.C Madu

Effects of wood ash, nitrogen and intra- row spacing on plant height, number of leaves and tuber

yield of potato (solanum tuberosum l.) at Kuru Nigeria G.L Daure, N.C Kuchinda, I.U Abubakar and L.Aliyu

Control of weeds using herbicide on cassava crop Frangoie Ngoie A., Mahungu N.M., Ndonda M., Mukendi T., Kilumba M.

Agronomic evaluation of new cassava (Manihot esculenta Crantz) clones with colored flesh in an ecology of southern Côte d’Ivoire

N’zue Boni, Zohouri G. Pierre, Ebah-Djedji B. Catherine, Kouakou Amani Michel, Paul Ilona and Dibi Konan B.E.

Lead and cadmium uptake characteristics of turmeric: effect of single and mixed contamination of two benchmark soils of Southeastern Nigeria.

Nwokocha, C.C., Ano, A.O., Olojede, A.O. and Igwe, C.A.

Comparison of cassava yield variations from four-year continuous cultivation under sole and mixed cropping systems in an ultisol of Eastern Nigeria Asadu, C.LA., A.G.O. Dixon and R. Okechukwu

Research gaps in cassava production environment: a review

Asadu, C.L.A.; S. Hauser and G.U. Nnaji Effet de précédents culturaux de Pachyrhizus erosus, de Mucuna pruriens, d’arachide et de maïs

sur la productivité du maïs au Centre-Bénin Antoine BADOU, Kouessi AÏHOU, Patrice ADÉGBOLA, Pascal FANDOHAN, Narcisse

TAÏWO, Basile ZANOU Evaluation of some newly released cassava varieties on growth performance using two and four

node stakes for stem production. Njoku, S.C., Egesi C.N, Ano .A, and Ikeogu, U.N.

Influence of yam sett-weights on tuber yield in two cultivars of Dioscorea rotundata E.K. N’KPENU [email protected]; Y.D. SUNU

Development of cost reducing weeding systems for cassava production in Nigeria

O.N. Eke-Okoro, N. J. Amanze, F. N. Nwakor, A. O. Akinpelu and O. C. Eke-Okoro, J. Mbe and V. Ekpe

42

Differential responses of sweetpotato cultivars to fertilizer NPK in a high rainfall area of

Southwest Nigeria V.O. Aduramigba-Modupe, A.O. Aduramigba-Modupe, A.O. Adetayo S.O. Olanipekunand A.O.

Denton Chemical and integrated nutrient management options sustainable yam production

S. A. Ennin E. Owusu Danquah and P. P. Acheampong

Post Vine Multiplication Evaluation of Microtuber Performance in Ghana E. Otoo, R. Asiedu, T. Appiah-Danquah, H. Kikuno

Analysis of the constraints to Seed Yam Production through the Yam Minisett Technique in Benue State, Nigeria

Tokula M.H. Ekwe, K.C and Ikeorgu J.G. Progress in staking options in yam production for adaptation to climate change

S. A. Ennin, E. Owusu Danquah, and P. P. Acheampong

Appropriate farming practices resilience to climate change : Case of cassava on non- incineration of a grassy fallow forest of Kisangani A.M Ndonda, N.M Mahungu, A.N Frangoie

Development and dissemination of yam vine multiplication techniques

E. Otoo, R. Asiedu, T. Appiah-Danquah, H. Kikuno Determination of maturity dates of some cassava varieties in DRC

D.Ndombo ; N M Mahungu; M Bidiaka and M.Kaziama

Maximizing cassava (Manihot esculenta Crantz) stems system in Tropical Africa M. O. Yomeni, M.O. Akoroda and A.G.O. Dixon

Growth and yield of taro under dryland as affected by fertilizer types and irrigation C. M. Tfwala and S.M. Dlamini

Organic ginger production in an ultisol in southeastern Nigeria Ebeniro, C. N. and Amadi, C. O.

Mineral fertilization of Pachyrhizus erosus (L.) Urban cultivated on degraded Oxisol in Southern

Benin M. R. Aguégué, A. Adjanohoun, P. Y. Adegbola, K. A. Djinadou-Igué, O. D.Koudandé, P. Fandohan and G. A. Mensah

Effects of climatic and soil variability on sprouting ability, disease response and yield of 0

cassava genotypes in different agro-ecological zones O.O. Etukudo, B. Maziya – Dixon and L.A. Babatola

43

Delivering the potential of potato in Mozambique: Challenges, opportunities and strategies

Charles Lung’aho, Martinho Carolino and Elmar Schulte-Geldermann

Yield and Micronutrient uptake of white yam (Dioscorearotundata L. Poir) as influence by organomineral fertilizer ammendment on an alfisol in Ibadan South western Nigeria Lawal O.I., G.O. Adeoye, R. Asiedu, Ojeniyi, S.O. Atayese. M.O. and A.O. O laiya

Varietal Response of Sweet potato (Ipomoea batatas) L Lam) to Fertilizer Regimes in Different

Agro ecologies in Nigeria Onunka N.A Tokula M.H. Nwankwo M .I .I Ehisianya C. N.

Response of four sweetpotato cultivars to water stress R. Laurie, S. Laurie & CP du Plooy

Water yam (Dioscorea alata l.) microsett responses to plant density and mulching in South Eastern Nigeria

Okpara, D.A., Ikoro A.I. and Ojikpong, T.O.

Evaluation of growth and yield response of sweetpotato (ipomea batatas l.) to diffe rent rates of poultry manure in Abeokuta Southwestern Nigeria Atayese Muftau Olaoye, Lawal, Omoniyi Isiaq, Afuape Solomon, Sakariyawo Olalekan

Sulaiman, Olaiya Abideen, Fetuga, Ganiyat Olayinka and Idowu Taiwo Hazanat Effects of Organic and Mineral Fertilizers on total Antioxidant, polyphenolic and carotenoid

contents of Orange fleshed sweetpotato tubers Moumouni Koala, Adama Hema, Koussao Some, Eloi Pale, Abdoulaye Sereme, Jerome Belem,

Mouhoussine Nacro Effects of Maize intercrop at varied densities on yields and β-carotene content of orange fleshed

sweetpotato Asiimwe A., Tabu I.M., Lemaga B., Tumwegamire S.

Best time of supplemental mulch application for turmeric production in a Rainforest Agro-Ecology of Nigeria

Olojede, A.O., Nwokocha, C.C., Akinpelu, A.O., Obasi, C.P and Ikeorgu F.

Evaluation of some improved and local yam genotypes for yield and yield components in northern Ghana J. Adjebeng-Danquah, S.K. Asante, K. Acheremu, A. Nimo-Wiredu, F. Kusi

Assessment of performance and farmers’ preference varieties through participatory variety

selection calls for doubling breeding effort in Zambia Ntawuruhunga P., Chiona M., Manda N., Korie S. and Njobvu J.

44

Soil physico-chemical properties and rainfall relationship with cassava growth and yield in Nsukka Southeastern Nigeria

Godwin Uche Nnaji

Comparing arable and plantation crop effects on soil chemical properties of eroded soils: a case study of Nanka erosion site in Ifite-Nanka, Orumba North Local Government area, Anambra State.

Okafor Chioma Mars I. M Uzoh, Okolo C.C, Ene Jude, Nwajiaku I.M, Udegbunam O.N and Obasi, S.C

Support to Agricultural Research for the Development of Strategic Crops in Africa (SARD-SC) M.O. Yomeni, N. Mahungu, A. Adebayo, P. Ntawuruhunga and C. Akem

Meeting supply of large volume of improved cassava stems to Nigeria farmers by IITA:

challenges, approach and achievements Okechukwu R., G. Tarawali and M. Fregene

Evaluation of three sweetpotato genotypes in sand hydroponics for vine production Mwanga R.O.M, Kyalo G, Low J, Ssemakula G.N. and Otazú V

Anticipated potential of nutrient efficient genotypes in the productivity of cassava in Africa K. Susan John, S.U. Shanida Beegum, M.N. Sheela and G. Suja

Status of ginger production in the Rain Forest Agro Ecological zone of Nigeria

Ewuziem, J.E. and Ironkwe, A.G Effects of environmental degradation on profitability of cassava production in Southeast Nigeria

Bolarinwa, O. K. and Osun, Taiwo

Combined effect of organic/inorganic fertilizer mixtures on turmeric production in a rainforest agro-ecology of Nigeria Olojede, A.O., Nwokocha, C.C., Ano, A.O., Akinpelu, A.O.

Influence of soil moisture stress on vegetative growth and root yield of some selected cassava

genotypes under green house condition Adetoro N.A., Parkes E., Oworu O.O., Aina O., Iluebbey P., Kulakow P.

Developing appropriate fertilizer management options for sweetpotato production in the agro-ecozone of Ghana

Felix Owusu Ababio Variation of Harvest Index and Dry Matter Content of Yam Bean (Pachyrhizus spp) Accessions

in two major Agro Ecological Zones of Uganda R. Agaba, P. Tukamuhabwa, P. Rubaihayo, S. Tumwegamire, and W.J. Gruneberg

45

Yield and Micronutrient uptake of white yam (Dioscorearotundata L. Poir) as influence by organomineral fertilizer ammendment on an alfisol in Ibadan South western Nigeria

Lawal O.I., G.O. Adeoye, R. Asiedu, Ojeniyi, S.O., Atayese. M.O. and A.O. Olaiya

Seed system lessons learned from Marando Bora in lakes zone, Tanzania Stephen Walsh and Lembris Laizer

Profitability and technical efficiency of cassava (Manihot esculanta) production in Ndokwa west local government area of delta state, Nigeria

Eze, A.V., Nwibo, S.U., Okolo, C.C., Ezeaku, P. I., Ezeudo, V.C., Chukwudi, P.U., Agbo, S.U and Eze, N. C

Seed System Innovations in the Great Lakes Cassava Initiative (GLCI) Stephen Walsh, Phemba Phezo, Elia Marandu, Julian Smith, Dai Peters and Michael Potts

Cassava Seed Regulations–Multi-Stakeholder Engagement to Increase the Relevance and Application of Stem Quality Standards. Data and insights drawn from Sustainable Cassava Seed

System (SCSS) Project in Nigeria Iruansi Itoandon, Lateef Towolawi, Stephen Walsh, Charles Iyangbe

Sustainable Cassava Seed Systems in Nigeria–A project overview with key achievements and lessons learned to date

Itoandon, S. Owoyemi, C.Iyangbe, S. Walsh

Physico-chemical properties of salad cream stabilized with cassava and potato starches Eke-Ejiofor, J; Williams, I. J and Owuno, F.

Effect of bio- fertilizers in the growth and yield of sweetpotato C. M. Tfwala

Productivity and field disease reaction of biofortified cassava genotypes in Nigeria Bello, A.A. Parkes, E., Aina, O.O.,Maroya, N.G, Kolawole, R., Akoroda, M.O., Kulakow, P.

BREEDING 195 - 238

On-station performance of cassava brown streak disease tolerant varieties in Zanzibar

Kanju, E., Saleh, H., Mohamed, S., Masumba, E, and Mtunda, K.

Strategies to enhance the use of Inbreds and Genetic Diversity to produce Superior Cassava Varieties

Okoro Perpetua, Kulakow Peter, Rabbi Ismail, Egesi Chiedozie, Essie Blay, I.K Asante, Gracen Vernon, Otene J.J Iduh

46

Evaluation of local germplasm for agronomic performance, diseases expression and root qualities

T. Ayankanmi, P. kulakow, E. Parkes, R. Ismail, O. Aina, P. Iluebbey and A. Ikpan

Flow behavior of three parts of yam tuber starch during the tuber growth Kouadio Claver Degbeu, Yao Denis N’dri and N’guessan Georges Amani

Morphological and agronomic characterization of root forming legume species in Uganda P. Tukamuhabwa, E. Oyesigye, B. Heider, S. Tumwegamire, and W.J. Gruneberg

Yield responses of sweetpotato (Ipomoea batatas) and soyabean (Glycine max) intercrop to nitrogen levels in south eastern Nigeria.

Obasi C.P, I.I.M Nwankwo, T.C Madu

Towards the development of Cryopreservation protocol for Solenostemon rotundifolius: Impact of pre-treatment Marian. D. Quain

How released sweetpotato varieties are distributed in Uganda and how perhaps they should be

Richard Gibson Seed Potato System in Nigeria: Status, Challenges and Prospects

Amadi, C. O., Lenka, D. M. and Dung, E. A.

Working with community based organizations to promote consumption of orange fleshed sweetpotatoes through on-farm participatory trials Ssemakula Gorrettie, Mwanga Robert, Ann-Marie Ball, Kyalo Gerald, and Namakula Joweria

Farmers’ methods of evaluating cassava varieties in tropical climatic conditions of western

Kenya Vincent W. Woyengo, Rob Melis, Paul Shanahan, Omari M. Odongo

Breeding cassava for enhanced β–carotene content for better nutrition: progress, challenges and prospects from Uganda

Williams Esuma, Robert Kawuki, Anthony Pariyo, Yona Baguma and Titus Alicai Evaluation of introduced yam genotypes in three agro-ecologies of Sierra Leone

P.E. Norman, J.B.A. Whyte, A.E. Samura, A. Massaquoi, L. Sesay, A.G.O. Dixon, S.N. Fomba, M.T. Benya and M.M. Sowa

Root and tuber crops species conserved at Plant Resources Center: Potential and Beyond for The Future in Vietnam

Nguyen Van Kien, Hoang Thi Nga, Nguyen Thi Hanh, Le Thi Hang, Le Van Tu, Nguyen Phung Ha

Genetic characterization of exotic and landrace of cassava (Manihot esculenta Crantz) in Ghana

47

K. Y. Karim, R. Akromah, J. A. Manu-Aduening

Landraces genes in cassava improvement Mahungu N.M., Bidiaka M., Binzunga M., Nluta S., Ndombo N.

Farmer Participatory Development of Four Sweetpotato Varieties in Ghana K. Adofo, J.N. Asafu-Agyei, J.N.L Lamptey, E. Carey, E. Baafi, E. Obeng-Bio, E. Adu-

Kwarteng, E. Owusu-Mensah, P. Acheampong, J. Haleegoah, Victor Amankwaah, N. Asamoah-Obeng and J. K Awoodzie

Genetic variability of six cassava traits across three locations in Ghana Peprah Bright Boakye, Agyeman Adelaide and Elizabeth Yaa Parkes

IITA Genebank: Sanitization and Distribution of Cassava Germplasm for breeding and research

Jekayinoluwa T.A, Gueye Badara, Abberton Michael Advances in Cassava (Manihot esculenta) and Yam (Dioscorea spp.) Breeding and Development

in Sierra Leone: 008-0 S.N. Fomba, J. B.A. Whyte, F. B. Massaquoi, P. E. Norman, A.E. Samura, A.G.O. Dixon,

M.L.S. Gboku, D. S. Fornah, L. Sesay, A. Massaquoi and F. Kobba Dry matter determinationin cassava - A better approach

P.O. Iluebbey, E.Y. Parkes, A. Agbona,O.O. Ainaand P.A. Kulakow

Effect of varieties on the adsorption isotherm of yellow-fleshed cassava root starches Awoyale, W., Sanni, L.O., Shittu, T. A., Adegunwa, M.O., Badara, G and Kulakow, P.

New approaches for Root and Tuber genetic resources conservation and use Gueye Badara and Abberton Michael

Determination of Beta-Carotene Content of yellow root cassava using iCheckTM Device A.O. Ogungbesan,, E. Y. Parkes, N. A. Maroya, O.O.Aina, P. I. Iluebbey, A.Agbona and P. A.

Kulakow

On farm participatory evaluation of improved cassava genotypes (manihot esculenta Crantz) in Sierra Leone F.B.Massaquoi, A. E. Samura, A. Mansaray, D. D. Quee, D. S. Fornah, L. Sesay, A. Massaquoi,

M. T. Benya and S. N. Fomba

Speed breeding and variety release for orange fleshed sweetpotato cultivar diveristy in Malawi FP Chipungu T Mkandawire, M Chitete IR Benesi, P Pamkomera, O Mwenye EP Abidin, M Andrade, W Gruneberg and M Chiipanthenga7

Genetic evaluation of potato genotypes for agronomic, tuber quality traits and resistance to late

blight in Jos Plateau, Nigeria. Danbaba, A.K., Lenka, D.M., Haruna, A.O., Ruth Damara and Mamud, M.B.

48

Breeding cassava for enhanced β–carotene content for better nutrition: progress, challenges and

prospects from Uganda Williams Esuma, Robert Kawuki, Anthony Pariyo, Yona Baguma and Titus Alicai

Farmer Participatory On-farm Evaluation of Yellow to Orange-fleshed Sweetpotato Accessions in Sweetpotato Based Cropping System of North Central Zone of Nigeria

Njoku, J. C. Afuape S., Nwankwo, I. I.M, Echendu, T.N.C. and E. Carey,

Introgression of Cassava Mosaic Disease resistance into farmer preferred cassava genotypes in Ghana Elizabeth Yaa Parkes, Martin Fregene, Alfred Dixon, Emmanuel Okogbenin, Bright Boakye

Peprah, Marian Dorcas Quain, Samuel Kwame Offei, Eric. Danquah, Maryke Labuschagne7

Evaluation of performance of introduced yam Bean (Pachyrhizus spp.) in three Agro-ecological zones of Rwanda J. Ndirigwe Musabyimungu A., E. G. Kayinamura, Tukamuhabwa P., W. Gruneberg and P.

Ndayemeye

Genotype by Environment Interaction and Productivity of New Generation Cassava Genotypes Developed for Food and Industrial Uses in Nigeria P. A. Kulakow O. O. Aina E. Y. Parkes M.Yomeni, J. Onyeka, C. N. Egesi, B.Olasanmi, P.

Iluebbey A. Agbona A. G. O Dixon

Genetic analyses of cassava segregating families for heritability and genetic gain of carotene content and other agronomic traits by parent-offspring regression Njoku D.N., Gracen, V.E. Offei, S.K., Asante, I.K., Egesi C.N., and Kulakow P.

Farmer Participatory Development of Cocoyam (Xanthosoma sagittifolium, Linn, Schott)

cultivars E.L. Omenyo, M.D. Quain, E. Moses, H. Asumadu, P.P. Acheampong, and A. A. Ankoma

Development of Cryobanking for Long term Ex-situ conservation of cassava Adeyemi Abigael O., Dumet Dominique, Gueye Badara, Abberton Michael

Genetic variation of yellow-root cassava clones for high yields and earliness in the guinea savanna ecology of Ghana

Kwabena Acheremu Joseph Adjebeng-Danquah and Emmanuel B. Chamba

Progress made at improving farmer-preferred cassava landraces in Ghana Manu-Aduening, J. A ., Peprah, B. B., Lotsu, E and Ohene, O.

On-farm assessment of field and culinary attributes of selected sweetpotato genotypes by farmers for varietal nomination and release

Afuape, S.O., Nwankwo, I.I.M., Njoku, J.C. and Echendu, T.N.C.

49

Intra and inter-seasonal variability of cassava genotypes for plant morphological traits associated with resistance to green mite Mononychellustanajoa (Bondar) (Acari: Tetranychidae)

Chalwe, A., R. Melis, P. Shanahan, and M. Chiona

Building collaborations to enhance research on an important but neglected crop, Taro (Colocasia esculenta) Joseph Onyeka Badara Gueye, Robert Asiedu, Leke Walter Nkeabeng, and Michael T. Abberton

Mining for resistant genes in African cassava landraces to cassava bacterial blight for

deployment in breeding Egesi C.N ., Onyeka T. J Parkes E., Peprah B., Ezeji L., Ijeh I. and Okogbenin E

Distribution of Sweetpotato planting materials in Northern Uganda P, Rachkara S. W. Kalule and R.W. Gibson

Response of selected cassava (Manihot esculenta Crantz) genotypes to root inducing hormone, IBA (Indole--butyric acid) under growth conditions

Shirley Otukpa Ismail Rabbi, Gueye Badara, Michael Abberton, Peter Kulakow

Analysis of Inbreeding Depression in Five S Cassava Families of African varieties Lydia Ezenwaka, Emmanuel Okogbenin, Olalekan Akinbo, Chiedozie Egesi, Favour Ewa and Alex Ogbonna

Biofortification of cassava for pro-vitamin A in Nigeria: a model for collaborative scaling out for

reduction of vitamin A deficiency in Africa Egesi C.N., Olasanmi B., Onyeka T. J, Njoku D., Ogbuekiri H. Okogbenin E., Ilona P., Parkes E.,and P. Kulakow

SOCIO ECONOMICS 239 - 271 Farmers’ Valuations of Cassava Variety Traits in Southern Ghana: The Mixed Logit Approach

Patricia Pinamang Acheampong Victor Owusu and Gyiele Nurah

Targeting agricultural research for development investments in cassava and yam production systems in Africa: Evidence from Nigeria Paul M. Dontsop Nguezet, Victor Mayong, Joseph Rusike

Socio-economic analysis of Yam bean (Pachyrhizuserosus) processing to Gari in Benin

Patrice. Y. Adegbola, Prosper Houessionon Paul. Houssou, Soniade Ahouignan Denis Olou Jean Louis Ahounou, Kerstin Hell, Graham Thiele, Pascal Fandohan, Guy. Apollinaire. Mensah.

Socio-economic analysis of Pachyrhizus erosus in South and Central Benin Patrice. Y. Adegbola, Prosper Houessionon Lys-Annie Loboté, Imayath Badarou Nestor

Alokpaï, Pascal Fandohan, Guy. Apollinaire. Mensah.

50

Analysis of the factors that Influence Root and Tuber Crops Production in Benue State Nigeria: Implication for improved Agricultural productivity.

Tokula, M.H. Wende, F. Ekwe, K.C. and Asumugha, G.N

Gender Enterprises in Cassava Production and Processing among Farmers in Abia State: The Case of Adopted Village Project Ekedo, T.O, Nwakor F.N, Okoye B.C, Ekwe K.C. Asumugha G.N

Constraint Analysis of Farmers Adoption of Sweetpotato Utilization Technologies in Southeast

Agro-Ecological Zone of Nigeria. Nwaekpe J.O., H.N. Anyaegbunam, G.N. Asumugha, K.C. Ekwe and B.C. Okoye

Refocusing Cassava Enterprises Towards Rapid Agricultural Transformation in Nigeria Ekwe K . C. Ironkwe A. G and Okoro Basil

Responsiveness of farmers’ to root crops technologies disseminated through mass contact channels in abia state

Ekwe K.C., Tokula M.H. Ekwe Chioma and Ironkwe, A G

Increasing Africa’s competitiveness in the Global Cassava Market through mechanized production and processing Kolawole, O. Peter and Abass, Adebayo

Analysis of transaction costs in cocoyam marketing in Abia State, Nigeria

Kadurumba Chinyere Global, regional and local drivers of change in cassava value chains in selected countries in

Africa: Implications for upgrading smallholder systems J. Rusike, A. Adebayo T.Abdoulaye, A. Alene, W. Bowser, V. Manyong

Priorities for research of a global cassava program in sub-Saharan Africa: Perspectives of scientists and farmers

J. Rusike T. Abdoulaye, G. Hareau, U. Kleinwechter, B. Creamer, D. Pemsl, H. Kirscht, A. Alene7

Effects of variety and fermentation periods on the yields of ethanol produced from sweetpotato flour and starch

Etudaiye, H. A., Oti, E and Sanchez, T

First Step toward the orange-fleshed sweetpotato value chain in Ghana: Linking extension to private seed producers. Kwabena Assure, Kwadwo Adofo, Kwabena Acheremu, Iddrisu Abdul-Rahaman, Sampson

Ndego, Sabastian C. Waltia, Abu Baayirinaa, Constantine Faar, Dadoza Mac, George Apetorgbor, Victoria D. Abankwa, Vincent Subbey, Appiah K. Boateng, Esi Amoaful, Eric

Dery, E. Carey

51

Transformation through Integrated Agricultural Research for Deve lopment (IARD): Experiences from Cassava Value Chain Innovation Platform – DONATA Project, Ghana.

Grace Bolfrey-Arku, Emmanuel Osei-Adade, I. O. O. Ansah, Joseph Manu-Aduening, Alfred Anaman, Jonas Adu,Thomas Asare Baffour, Ebenezer Aboagye, Patterson Ose i Bonsu

Community Analysis of Root & Tuber Crops Farming System in Southeastern Nigeria Asumugha, G. N., H. N. Anyaegbunam, B. C. Okoye and J. C. Okonkwo

Cassava Products Development in Nigeria; Policy Imperatives.

Okafor, Obiageli Evelyn; Ogunwusi, A.A. and Jolaoso, M.A. Processing and marketing of Fried Cocoyam (Xanthosoma sagittifolium) Chips in Ajilete, Ogun

State Nigeria Idowu-Adebayo Folake Sanni, L.O, Adebowale, A.A, Adegunwa, M.O and Oni, O.K.

Farmer preferences for cassava attributes in Oyo State, Nigeria: A choice experiment investigating potential adoption of vitamin A enriched yellow cassava

Dorene Asare-Marfo, Ekin Birol and Adewale Oparinde

Gender operation and labour utilization in sweetpotato production in Ebonyi State Southeastern Nigeria G.O. Nwaigwe, M. Mazza, and E. C. Agoh

Price integration analysis of some selected cassava root markets in south Eastern Nigeria

Anyaegbunam,H.N, Nwaekpe J, Asumugha G.N and Okoye,B.C Farmers’ perceived adoption risks associated with Nicola varie ty of potato in Jos Plateau,

Nigeria Ekwe K.C, Anyaegbunam H.N, Amadi C.O, Dung E.A, Dalyop T Y, Lenka D

The health benefit of the nutrient and phytochemical compositions of sweetpotato: - A review Alum, E. A., Amajor J.U. and Awah J. I.

Level of awareness, factors and constraints to sustainable adoption of improved root and tuber

crops in Abia State, Nigeria Edoh, N. L., Nwaogu, A.S. and Egesi, C.N.

Potential for commercialization of cassava production in the Mpumalanga province of South Africa

M.E. Rauwane N.M Vilane and T.G. Chabikwa Analysis of the factors influencing sweet potato in south eastern Nigeria

Igwe C. O.K, Asumugha G.N, Igwe, K.C and Anyaegbunam H.N

Determinants of farmers’ willingness to export yam in Ibarapa east and Ibarapa central local government areas of Oyo State

52

Adesiyan O.F., Adesiyan A. T., Yesufu, O. A. and A. L Lasisi

Impact and adoption of value added innovations in root and tuber crops among farmers in cross river state, Nigeria.

Aniedu, C., Aniedu, O. C. and Nwakor, N. Analysis of the value chain of sweet potato and household food security in Southern Benin

Abdul-Baaki Bankole Patrice Y. Adegbola Arnauld K Aguemon, Esaïe Gandonou

How small-scale farmers learn from the market Moses Matui Paul Ingenbleek Anita Linnemann, Hans van Trijp Abass Adebayo

Gender perception of climate change and adaptation among small-holder cassava farmers in Anambra State, Nigeria

Madu, T. U., Okoye, B. C and Chinaka, C. C Optimum combination of major root crop based enterprises and resource allocation by

smallholder farmers in Abia State, Nigeria K. C. Igwe C. E. Onyenweaku C. O. K. Igwe and G. N. Asumugha

PATHOLOGY 272 - 298

Community Phytosanitation: Progress in Cassava Brown Streak Control through Clean Seed K.J.Mtunda I. Ndyetabura, J. Legg, J. Ndunguru, A. Mwenisongole F.Kaminyoge, I. Lwabuti,

and E. Shumbusho7 Occurrence of sporadic dry root rots caused by Phaeolus manihotis Heim (Basidiomycete;

Polyporaceae) on cassava in the Bas-Fleuve district of DR Congo and attempts for its control Kassongo W. Tata Hangy, K. Bambala, S. Nluta, Lyna Mukwa and Nzola M. Mahungu

In vitro inhibition of fusarium by Lactic Acid Bacteria (LAB): Implication of yam disease control for economic growth in Nigeria

Omodamiro R.M, Ojimelukwe, P.C, Asiedu, R and Omodamiro, O.D

Effect of different stake portions on cassava mosaic disease expression and yield of three cassava varieties under natural field infection I. A. Smith,O.O Aina, E. Y. Parkes, P. O. Iluebbey, A. Agbona, I. Y. Rabbi, M. Gedil. P. A.

Kulakow

Evaluation of four plant extracts in the control of post-harvest tuber rot of Irish potato (Solanum tuberosum) Ogunsola J. F and Aduramigba-Modupe A. O

Effect of some plant extracts and pesticides in the control of Bacterial Leaf Blight disease of

Colocasia esculenta caused by Xanthomonas campestris in Umudike, Abia State Nigeria

53

Opara, E. U. Isaiah, E. C. Eze, E. C. Okolo C. C., Ezeaku, P. I., Chukwudi, P. U., Ezeudo, V. C., Osadebe, V. O., Okechukwu, E. C., Amuji, C. F. and Imegwu, C.

Field response of pacific accessions of Colocasia esculenta to taro leaf blight disease in Nigeria

Onyeka T. J., Ezeji L., Chukwu, G., Amadi, C., Okoye B. C. and Mbanaso, E.N.A. Isolation and identification of Meyerozyma guilliermondii from yam steep water of traditional

dried yam ‘gbodo’, using molecular techniques Joan M. Babajide, Robert Skilton, Solomon Maina, Gbenga Adewumi, and Funmilayo Adeniran

Molecular-based diversity of the scale insect Stictococcus vayssierei in the Congo Basin: evidence of the existence of a species complex

Armand Doumtsop, Rachid Hanna Abraham Fomena, Benjamin Normark, and Willy Tata Hangy

Boric acid for the suppression of the ant, Anoplolepis tenella and impact on infestations of its tended scale insect, Stictococcus vayssierei in cassava fields Apollin F. Kuate Rachid Hanna Samuel N. Nanga Maurice Tindo and Peter Nagel

Characterization of microorganisms isolated from cassava peel wastes

Gbenga Adedeji Adewumi Olusola Bandele Oyewole Initiatives by IITA to pre-empt cassava diseases and climate change to enhance food security in

Burundi and Rwanda Emmanuel Njukwe Ntawuruhunga Pheneas, Bigirimana Simon and Gashaka Gervais

Pests and diseases status of local and improved cassava genotypes in selected pilot sites in Cameroon

Maurice Tindo, Emmanuel Njukwe and Abdou Tenkouano

Identifying Cassava Mosaic Disease Resistant genotypes for industrial and local uses In Sierra Leone. A.E.Samura., F.B. Massaquoi., L.Kumar., J.P.C Koroma., M.T.Lahai., S.N.Fomba and A.G.O.

Dixon

Comportement de variétés de manioc en diffusion et en développement à l’infestation par la cochenille africaine des racines et tubercules Stictoccocus vayssierei Richard (Hemiptera: Coccoidea) dans le Nord Kivu

N. Eleko; K M. Lema; R. Hanna; Mahungu N M

Management of sweetpotato weevil, Cylas puncticollis (Boh.) (Coleoptera: Brentidae) infestation using varietal and cultural control at Kuru, Nigeria C. N. Ehisianya and N. A. Onunka

Pests and diseases status of local and improved cassava genotypes in selected pilot sites in

Cameroon Maurice Tindo, Emmanuel Njukwe and Abdou Tenkouano

54

Monitoring survey and status of the Cassava Anthracnose Disease (CAD) in Luapula and Eastern

Provinces of Zambia Mathias Tembo and Patrick Chikoti

Genotypic Resistance of Yam (Dioscorea spp) to Post-harvest Microbial Rot Nyadanu, D., Dapaah, H. and Agyekum, A.D.

Pests and diseases associated with yam bean (Pachyrhizus erosus) cultivation at farmers’ levels

in the central region of Benin A. Bouraïma R. Sikirou, P. Y. Adégbola, A. Adjanonhoun, B. Zocli, L. Gnancadja, M. Sézolin, K. Hell, K. Ahiou, Feu P. Fandohan and G. A. Mensah.

Molecular characterisation of a novel cassava associated circular ssDNA virus

Anisha Dayarama, Allen Oppongb, Anja Jäschkeac, James Hadfielda, Marianna Baschierad, Renwick C.J. Dobsonaf, Samuel K. Offeig, Dionne N. Shepherdd, Darren P. Martine, Arvind Varsaniafh

Can we maintain cassava clean seed systems using certification guidelines that incorporate virus

testing? A comparison of standard and real-time PCR testing techniques Rudolph R. Shirima, Frank Fovo, Juma W. Yabeja and James P. Legg

Taro leaf blight disease: Solutions for West and Central Africa Walter N. Leke, Victorine Fornkwa, Badara Gueye, Rachid Hanna, Joseph Onyeka, Michael T.

Abberton and Robert Asiedu Occurrence of sporadic dry root rots caused by Phaeolus manihotis Heim (Basidiomycete;

Polyporaceae) on cassava in the Bas-Fleuve district of DR Congo and attempts for its control Kassongo W. Tata Hangy, K. Bambala, S. Nluta and Nzola M. Mahungu

Characterizing the effects of degenerative diseases of cassava and yam P. Lava Kumar D. Coyne and J. P. Legg

BIOTECHNOLOGY 299 - 313

Application of biotechnology to yam improvement in CSIR-Crops Research Institute (CRI)

Quain, M,D., R.N. Prempeh, A. Agyeman, J.Y. Asibuo, E.Y. Parkes, P.F. Ribeiro, E. Otoo and M. Egnin

Screening of cassava genotypes for resistance to cassava mosaic disease using morphologica l and molecular markers

P. A. Asare I. K. A. Galyuon, E. Asare-Bediako, J. K. Sarfo and J. P. Tetteh

Phenotypic evaluation of a multi- location cassava breeding trial to improve a genomic selection training population

55

U.K. Uchendu, E. Parkes O.O. Aina M.O. Akoroda, P. Kulakow

Technical efficiency analysis of cassava production in Nigeria; implication for increased productivity and competitiveness

Osun Taiwo Ogundijo Stephen Dayo and Bolariwa K.O. Phenotipic evaluation of cassava mapping population for drought resistance traits in the Guinea

Savannah ecology of Ghana. K. Acheremu J. Adjebeng-Danquah E. Parkes, A. Agyemang, B. Pepra, E. Okogbenin, O.

Akinbo, C. Egesi, F. Ewa A survey of yam diversity, production and utilization in southern Ghana

Aboagye, L.M., M. O. Opoku-Agyeman and S. K. Owusu

Determinants of Technical Efficiency among Seedyam Entrepreneurs in Anambra State. Onwuka S., Mbanasor J. A., Ekwe K. C.

Impact of Taro Leaf Blight on Supply Response of Cocoyam in Nigeria: Implications for Cocoyam Trade

Okoye, B.C., Chukwu, G.O., Onyeka, J., Onwubiko, O and Okpechi, I Determinants of root crops cultivation: Potential safety crops in the face of increasing aridity in

southern Africa. S. Siziba, A. A. Adekunle and K. Nyikahadzoi

Identification of molecular markers associated with early bulking in cassava (Manihot esculenta Crantz)

Olasanmi B.,, M.O. Akoroda E. Okogbenin, C. Egesi, S.S. Kahya, O. Onyegbule, F. Ewa, J. Guitierrez, H. Ceballos, J. Tohme and M. Fregene,

Cassavabase (cassavabase.org): an integrated field breeding and genomics database enables accelerated genetic gain in cassava

Afolabi Agbona Ismail Rabbi Lukas Mueller and Peter Kulakow

Diversity analysis of sweetpotato (Ipomoea batatas [L.] Lam) germplasm from Burkina Faso using morphological and SSR markers Somé Koussao Vern Gracen,, Isaac Asante, Eric Danquah, Jerôme Belem and Jeremy Ouedraogo

In vitro low cost propagation of sweet potato plantlets: The cassava starch option.

Alfred O. Ubalua, Ihezie, I. C., Ikpeama, A. I., Mbanaso, E.N.A. and C. N. Egesi. Genetic studies and breeding using next-generation sequencing markers in cassava

Ismail Y Rabbi, Delphine Ly, Peter Kulakow Melaku Gedil Martha Hamblin, Jean-Luc Jannink,

56

PROTECTION 314 - 315

Quantifying millipede (Diplopoda) damage on cassava (Manihot esculenta crantz) and cocoyam (Xanthosoma sagittifolium (l.) schott) in the Western Region of Ghana K.O. Fening, i. Adama M. B. Mochiah M. K. Billah, H. Braimah M. Owusu-Akyaw and J. A.

Manu-Aduening.

Intercropping cassava with plantain impacts pest population dynamics and damage and plant growth and development. Haruna Braimah, Issa, U.S., Kingsley Osei, Manu-Aduening, J. Ankomah, A.A., and Mochiah,

M.B.

ROOT AND TUBER 316 -

CGIAR Research Program on Roots, Tubers, and Bananas (RTB): engaging partners and enhancing impact

Graham Thiele Characterization of Begomovirus strains found on Sweetpotatoes (Ipomoea batatas (L) in Ghana Linda A. Abrokwah

, Charles Kwoseh, Ted Carley, Marian Quain, Elizabeth Parkes, Allen Oppong

Spatio-temporal variation in cassava (Manihot spp.) in forest savannah eco-climatic zone of Nigeria Adetayo A.O. and and V.O. Aduramigba-Modupe

Can primary producers sustainably derive higher financial benefits from direct engagement in mechanized cassava processing? Bachwengizi, B.; Towo E., Mling i, N., Omari, M., Ranaivoson, R, Rabemanantsoa, N., and Abass, A.

The use of some alternative energy sources [cassava (manihot esculenta), sweet potato (ipomea batatas), and cocoyam (xanthosoma sagittifolium schott.)] For poultry and pig production and it’s implications for food security. Chid imma L.

Obi, Chika E. Oyeagu ,Augustine O.

Ani

Petrus E. Nwakpu, Scholastica N. Okongwu, Pat ience N.

Onu, Ugochukwu S. Ekwu, Murphy B. Enwezor.

Performance of some promising sweetpotato cultivars in the Uniform Yield Trials Gerald I. Serenje, Dr. Martin Chiona and Dr. Able Chalwe

Development of NRCRI cassava root harvesting aid Ikejiofor, M.C. and Okwesa, C.O

Seed yam multiplication and distribution to farmers in Nigeria: the contribution of Coraf/Wecard, 2009-2012 J.g. Ikeorgu and e.a. Asiedu

Performance optimization of a cassava pelleting machine

57

Kadurumba Chukwuma Henry

Determination of the factors of variability of the glycemic index of yam (Dioscorea cayenensis-rotundata) Nestor Kouakou Kouassi Georges GnomblessonTiahou and Georges N’Guessan Amani

Effect of some plant extracts and pesticides in the control of Bacterial Leaf Blight disease of Colocasia

esculenta caused by Xanthomonas campestris in Umudike, Abia State Nigeria

Opara, E. U., Isaiah, E. C., Eze, E. C., Okolo C. C., Ezeaku, P. I., Chukwudi, P. U., Ezeudo, V. C., Osadebe, V. O.,

Okechukwu, E. C., Amuji, C. F. and Imegwu, C.

Optimization of Growth and Amylase production by Aspergillus flavus grown on cassava peel Sani , A.

The use of yam bean Pachyrhizus erosus var EC KEW storage root in the African giant snails (Achatina achatina) feeding in Benin S.C.B. POMALEGNI; K.K.C. KINGUELEOUA

; P.Y. ADEGBOLA; S.E.P MENSAH

; M.S.E. GUEDOU ; M. M.

A. ANATO ; M. DAHOUDA ; G.A MENSAH

.

The 12th Triennial Symposium International Society for Tropical Root Crops-Africa Branch

(ISTRC-AB)

57

POST HARVEST

Nutritional, Chemical and Sensory properties of ‘Pupuru’ subjected to

fermentation of cassava with selected species of Rhizopus and their

combinations

Adejuyitan, Johnson Akinwumi and Otunola, Ezekiel Tejumola

Department of Food Science and Engineering, Ladoke Akintola University of Technology,

P.M.B 4000, Ogbomoso, Oyo state, Nigeria. E–mail: [email protected];

[email protected] .ng

Abstract

In the recent, the use of non-pathogenic micro-fungi to produce fermented foods and feeds, which originated in the orient, is already gaining popularity in both developed and developing

countries of the world. In this study, influence of fermentation using selected species of Rhizopus on cassava to produce pupuru flour (cassava product) was studied. Grated cassava

pulp (mash) was inoculated with pure culture of Rhizopus oligosporus, Rhizopus oryzae and Rhizopus nigricans singly, their combinations and their consortium. The mash samples

were allowed to ferment for 2, 4 and 6 days and subsequently processed into ‘pupuru’. Some

nutritional properties and proximate composition were analyzed using established standard procedures. Sensory evaluation was also carried out on the cooked pupuru .The results of

the ‘pupuru’ flour samples indicated a significant increase (pd”0.05) in the protein content with inoculated samples (7.24-11.94%) with single and combination of species of Rhizopus

while the control samples without the inoculation with Rhizopus species had mean protein content of (3.31-3.41%). There was an increase in the protein content as the fermentation

days increased. Similarly there was a significant increase in the fat content of pupuru flour

with inoculation with single and combinations of species of Rhizopus. There was no significant change in the fiber content of the samples. Determination of cyanogenic potential indicated

a significant reduction to a safe level (5.10-7.54mgHCN equivalent/100g). Sensory evaluation indicated that cooked pupuru samples from the control samples that were naturally fermented

were well accepted although cooked pupuru samples from inoculated cassava mash compared favourably in terms of taste, colour and mouldability.

Keywords: Cassava, Pupuru, Nutritional enhancement, Fermentation days, acceptability

mailto:[email protected]




(ISTRC-AB)

58

Microbiological assessment of dried mushroom in different packaging materials

*Ajayi, O.A., *Obadina, A.O., **+Adegunwa, M.O., *Sobukola, O.P.,

*Adebowale, A.A., Omemu, A. M., ***Asagbra, Y., ***Akinyemi Akinrinola, O. A., ***Asiru, W., *Sanni, L.O. and ****Tomlin Keith

*Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta. Nigeria

**Department of Foodservice and Tourism, Federal University of Agriculture,

P.M.B. 2240, Abeokuta. Nigeria

***Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria

****Natural Research Institute, University of Greenwich, Kent, Chatham, United Kingdom

*** [email protected]

Abstract

This research work reports the effect of different packaging materials (high density polyethylene, polypropylene, laminated aluminium foil, vacuum packaging) and storage

conditions (ambient, refrigeration and freezing temperature) on the microbiological quality of dried mushroom harvested from cassava peels. Each dried sample was analysed after 12

weeks of storage for its microbial load; total aerobic count, Pseudomonas spp , Staphylococcus spp and total coliform. Dried mushroom packaged in high density

polypropylene at ambient temperature (HDPE) showed total aerobic count, Pseudomonal count, Salmonella count 2.46, 2.31, 1.91, and 1.32 log cfu/g respectively. For dried mushroom

packaged in HDPE at refrigeration temperature , the count of total aerobic count,

Pseudomonal spp and Salmonella spp were 2.84, 2.13 and1.23 log cfu/g respectively. High density polyethylene dried mushroom stored under freezing temperature gave the count

of 3.67, 0.75, 1.22 log cfu/g for total aerobic count, coliform and staphylococcal count respectively. Dried mushroom in laminated aluminium foil at ambient temperature gave the

count of 3.12, 2.32 and 1.36 log cfu/g for total aerobic count, Pseudomonal count, and Coliform count respectively. Dried mushroom in laminated aluminium foil at refrigerated

temperature gave the count of 2.45, 1.54, 1.28, and 0.67 log cfu/g for total aerobic count, Pseudomonal count, Coliform and Pseudomonal count respectively. In vacuum packaging

at refrigeration temperature, total aerobic count, Pseudomonas and Staphylococcal count

gave the result of 2.61, 1.06 and 0.32 log cfu/g while vacuum packaging at freezing temperature shows gave 3.13, 2.32, 1.69 and 0.37 log cfu/g for total aerobic count, Pseudomonal spp,

Coliform count and Staphylococcal count. In conclusion, dried mushroom packaged under vacuum and stored at refrigeration temperature gave mushroom that was microbiologically

acceptable in relation to the microbiological criteria for ready to eat food; this will increase the shelf-life and availability of mushroom in the market.

Keywords: Dried mushroom, total aerobic count, Pseudomonas spp, Coliforms



(ISTRC-AB)

59

Functional and pasting properties of high quality cassava-tigernut composite flour

1Kareem, S.T., 1*Adebowale, A.A., 1Sobukola, O.P., 1Obadina, O.A.,1Kajihausa,

O.E., 2Adegunwa, M.O., 1Sanni, L.O., 3Tomlins, K. 1Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria. 2Department of Foodservice and Tourism, Federal University of Agriculture,

Abeokuta, Nigeria. 3Natural Resources Institute, University of Greenwich, United Kingdom

* [email protected]

Abstract

The functional and pasting properties of high quality cassava flour (HQCF) and tigernut flour were investigated in this study. Yellow flesh cassava root were peeled, grated, dewatered,

pressed and dried while the tigernut tuber were cleaned, dried and both samples were milled and sieved into flour. HQCF was blended with tigernut flour at the ratios of 90:10, 80:20,

70:30, 60:40, 50:50, 40:60, 30:70, 20:80 while whole HQCF and TNF serves as controls. The

blends and control samples were then subjected to analysis for pasting and functional properties. Data obtained were subjected to analyses of variance (ANOVA). The mean values for

water absorption capacity, Oil absorption capacity, bulk density and water binding capacity ranged from 0.57 to 1.33 ml/g, 1.67 to1.73 ml/g, 211.73 to 221.30% and 0.62 to 0.71 g/ml

respectively. The dispersibility, emulsification capacity, foaming capacity and Least gelation concentration ranged from 63.67 to 75.00%, 38.42 to 48.05, 4.26 to 15.47 and 2.00 to 5.33

respectively. The result of pasting properties shows that the peak, trough, breakdown, final

and setback viscosities ranged from 17.28 to 322.47 RVU, 15.14 to 135.92 RVU, 2.14 to 186.56 RVU, 34.67 to 191.78 RVU, 19.53 to 55.86 RVU, respectively. The peak time and

pasting temperature however varied between 3.87 to 5.04 minutes and 0.00 to 77.72 ºC. Significant differences (p<0.05) were observed in the functional and pasting properties of

the flour samples.This shows the possibility of using this composite flour in food formulation and for a wide variety of food such as breakfast meal, weaning food, functional snacks etc.

Key words: yellow flesh cassava, tigernut, functional and pasting properties



(ISTRC-AB)

60

Effects of different processing methods on the nutrient composition and functional properties of flour from false yam tuber (icacinao liviformis).

1Ariwaodo C.A and 2Ohuoba A.N

National Root Crops Research Institute Umudike, Abia State.

[email protected]

Abstract

False yam (icacinao liviformis) is a drought resistant underutilized plant of west and central Africa which produces large starchy tuberous root. This root was treated with five different processing methods which are; Boiled/oven-dried, oven-dried/roasted, Blanched/oven-dried,

fermented/oven-dried and oven-dried as control. Chemical and functional analysis was carried

out on the flour products. The average mean of carbohydrate recorded lowest in oven-dried (66.757%) and highest in oven-dried/roasted (75.336%) whileMoisture content was highest

in oven-dried (8.043%) and lowest in oven-dried/roasted (2.1%), the Fat content ranged from 0.58% in oven-dried to 0.206% in Blanched/oven-dried. Protein content ranged from

5.41% in oven-dried to 8.72% in fermented/oven-dried.Ash content ranged from 2.19% in oven-dried to 4.5% in fermented/oven-dried while crude fibre ranged from 13.36% (Blanched/

oven-dried) to 17.02% (oven-dried).In functional analysis, loose bulk density ranged from

0.385 in oven-dried to 0.588g/ml in Boiled/oven-dried; Packed bulk density ranged from 0.556g/ml in oven-dried to 0.80g/ml in boiled/oven-dried. Water absorption capacity ranged

from 2.9g/ml in oven-dried to 4.1g/ml in boiled/oven-dried; while Oil absorption capacity increased from 1.8g/ml in boiled/oven-dried to 2.4g/ml in fermented/oven-dried. Swelling

index ranged from 1.15g/ml in oven-dried to 2.17g/ml in Blanched/oven-dried. Solubility was lowest in fermented/ oven-dried (1.38%) and highest in oven-dried/ roasted (5.79%).

Gelatinization temperature was highest in Boiled/oven-dried (890C) and lowest in fermented/

oven-dried (700C) while forming capacity increased from 4.44% in oven-dried to 14% in fermented/oven-dried. Statistical analysis showed significant differences (pe”0.05) among

the treatments for both nutrient composition and functional properties.

Keywords: False yam, Processing, Flour, Utilization, Food Security, Nutritional and Functional

Properties.



(ISTRC-AB)

61

Evaluating the Potentials of wild Trifoliate yam (Dioscorea dumetorum) for

increased Utilization in Nigeria.

1Ezeocha V.C., 2Ojimelukwe, P.C., 2Onwuka, G.I

[email protected] 1National Root Crops Research Institute, Umudike, PMB 7006 Umuahia, Abia state, Nigeria.

2 Michael Okpara, University of Agriculture, Umudike, PMB 7267 Umuahia, Abia State, Nigeria.

Abstract

The wild Dioscorea dumetorum makes a significant contribution in the diet of some tribes in the south-eastern part of Nigeria where they are referred to as ighu. The tubers have been reported to be rich in protein and minerals, however its utilization is limited by its bitterness

which is caused by the presence of a toxic alkaloid; dihydrodioscorine.They are usually

detoxified by submerging in running water and thorough processing before being consumed as food. The wild yam tubers of Dioscorea dumetorum were evaluated for their phyto-

chemical composition. The dried and powdered tubers were extracted with ethanol for 48 hours and compounds present in the extract were identified by GC-MS analysis. 13

Compounds were identified; they included fatty acids and their esters, phenols, sterols, Aldehydes and ketones, hydrocarbons and amines.Wild Dioscorea dumetorum contained

some compounds which have been reported to possess beneficial biological activities. Such

compounds include: Phenols such as 3,5-di-t-butyl phenol (reported to possess antimicrobial, antifungal and anti-inflammatory activities), Flavonoids such as trans-3,4,4,5-tetramethoxy

chalcone (reported to possess antioxidant, anticancer and antimicrobial effects).Unsaturated fatty acids such as oleic acid (reported to be hypotensive and possess fungistatic and

antinflammatory effect), linoleic acid (essential fatty acid).Sterols such as 17-(1,5-dimethyl hexyl-10-13-dimethy l-1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-/H-cyclo-

penta[a]phenanthren-3-ol) (reported to reduce blood levels of cholesterol. From this

investigation, it was recommended that the exploitation of wild D. dumetorum for food should be encouraged not only because of the nutritional benefits but also because of the potential

health benefits.



(ISTRC-AB)

62

Ameliorative potentials of cocoyam (Colocasia esculenta L.) and unripe plantain

(Musa paradisiaca L.) on renal and liver growths in Streptozotocin induced

diabetic rats

1Eleazu, C.O., 2Iroaganachi, M. and 3Eleazu K.C.

1Department of Biochemistry, National Root Crops Research Institute, Umudike, Nigeria. 2Department of Food Science and Technology, Abia State Polytechnic, Aba, Nigeria. Email: 3Department of Biochemistry, Michael Okpara University o f Agriculture, Umudike, Nigeria.

Email: [email protected], [email protected]

Abstract The ameliorative potentials of cocoyam and unripe plantain incorporated feeds on renal and

liver growths in Streptozotocin rat models were investigated. The blood glucose level of the rats was measured with a glucometer; rat urinary glucose content, specific gravity (SPGR)

and protein contents were measured using test strips, Urinometer and Biuret methods respectively. The chemical composition and antioxidant assay of the test feeds were determined

using standard techniques. Administration of the test feeds to the diabetic rats resulted in 58.75 and 38.13% decreases in hyperglycemia and amelioration of their elevated urinary

protein, glucose, SPGR, renal and liver growths. The diabetic rats administered cocoyam

incorporated feeds, had 2.71 and 19.52% increases in body weight and growth rates (GRs) unlike the diabetic rats administered unripe plantain feed that had 5.12 and 29.52% decreases

in weight and GRs but better than the diabetic control rats that recorded 28.69 and 29.46% decreases in body weights with corresponding 248.9 and 250.14% decreases in GRs. The

test feeds contained low quantities of moisture but considerable amounts of crude fibre, proteins, lipids, carbohydrates, ash, alkaloids, flavonoids, saponins, tannins, calcium, magnesium,

potassium, iron, zinc, phosphorous and energy value. The cocoyam incorporated feeds

contained higher quantities of flavonoids, saponin, tannin, Ca, Mg, Fe, Zn, K, P, crude fibre and antioxidant activity but lower quantities of alkaloids than unripe plantain. The use of

cocoyam and unripe plantain in the dietary management of diabetes could be a breakthrough in the search for plants that could prevent the development of diabetic nephropathy.





(ISTRC-AB)

63

CONSUMER INSIGHTS AND ACCEPTANCE OF SWEETPOTATO

PRODUCTS IN GHANA Charity Bidemi WIREDU1,2, Edward CAREY1, Ibok ODURO2, Eric OWUSU MENSAH1

and Eric Kuuna DERY1

1International Potato Center, c/o CSIR-CRI, Kumasi, Ghana 2Dept. of Food Science and Technology, KNUST, Kumasi, Ghana

Abstract

Spreading knowledge about sweetpotato among the public is essential for promoting production, purchase and consumption of this crop. The decision to adopt new cultivars of sweetpotato

is driven by consumer and market acceptance more than by yield alone. This research therefore evaluated knowledge and attempted to discern purchasing and consumption drivers of

sweetpotato by consumers in Ghana. The study was conducted in localities in the Volta,

Central and Upper East regions. Three hundred valid surveys were collected (45.9% male and 49.8% female; age range of 10 – 65 years). Sweetpotato was mainly considered as a

snack food. The white (39.8%), yellow (39.2%), orange (12.9%) and purple (8.1%) fleshed cultivars were often consumed. Its sweetness (55%) and nutritional (21%) attributes were

major purchase incentives. Sweetpotato was usually consumed in boiled (42.9%) and fried (35.3%) forms. Most respondents (74%) had not recieved information promoting sweetpotato.

Nevertheless, all respondents were interested in receiving knowledge on sweetpotato. Television, radio, extension workers and teachers were considered as important potential

pathways for promoting knowledge on sweetpotato. The sweetpotato issues of concern

were mainly the bitter taste of some cultivars, lack of product diversity, limited information on health benefits and scarcity of sweetpotato in markets. Assessment of consumer acceptance

of fried sweetpotato samples from twenty four cultivars showed variations in acceptability among cultivars and between locations. Out of the 24 cultivars tested, 7, namely Naspot 2

(2), Jitihada, 442162, 442267, BUN 5, 91/282-1/35 and AP/3A were found to be most acceptable in all the locations. Sensory evaluation also indicated that acceptability of the

products was strongly related to taste (r = 0.69) than colour (r = 0.04) and flavour (r = 0.36).

The implication of the study is that, raising awareness of the health benefits associated with high sweetpotato consumption and diversifying products from sweetpotato may increase

purchase and consumption. Creating sensory profiles relating to the sensory attributes of the cultivars preferred by consumers would make it possible to screen other cultivars within

breeding programmes for those close to this profile and make modifications where necessary.


(ISTRC-AB)

64

Processing of yellow-fleshed based cassava salad cream: carotenoid content

optimization

Chijioke, U. Udugwu, A. Oti, E and Ofoeze, M.A National Root Crops Research Institute Umudike, Nigeria

* [email protected]

Abstract

This paper investigated means of recovering carotenoids lost in effluents generated during processing of cassava starch, a major ingredient for preparing salad cream from yellow –

fleshed cassava varieties. Salad cream samples were prepared from two yellow- fleshed

cassava genotypes (NR01/0211 and NR11/0157); while a commercially processed salad cream (Heinz brand) was used as reference material. Total carotenoids content of the fresh

cassava roots, sediments from starch effluent, yellow-fleshed cassava salad cream samples, plain salad cream samples and commercially prepared samples were determined using Harvest

plus method. pH of salad cream samples were also determined on 1st and 2nd day after processing using standard procedures. Result obtained showed that 55% and 69.77% of

total carotene content was recovered from effluents generated during starch processed from

NR11/0121 and NR11/0157 respectively. In-cooperation of recovered material to starch during product preparation increased total carotene contents of the salad cream to 76.2% and 71.30%

in samples processed from varieties NR11/0121 and NR11/0157 respectively. Samples processed using this method had improved colour and acceptability when compared to plain

salad cream. Storage of salad cream samples at room temperature for 48hrs after processing improved p H products to recommended standard.



(ISTRC-AB)

65

Growth performance of broilers fed taro cocoyam (Colocasia esculenta)

peels meal.

Okereke, C.O. and Okereke, I.H.

National Root Crops Research Institute, Umudike, Abia State, Nigeria.

*eogbokereke2009@yahoo .com

Abstract

Taro cocoyam (Colocasia esculenta) peels meal as feed ingredient in broilers diets was investigated using 150 one week-old Lowman Brown strain broiler birds. They were randomly

assigned to five (5) dietary treatment groups having 3 replicates with 10 birds per replicates

in a completely randomized design (CRD). Diet I was control diet (maize based). The taro cocoyam peel replaced maize at 5%, 10%, 15% and 20% in diets II, III, IV and V respectively.

Water and feeds were offered ad libitum for a period of 56 days. The result of the growth performance showed that the mean final weights and daily weight gain followed similar trend

with diet I and II significantly (P<0.05) higher than broilers fed diet V but statistically similar with diets III and IV. Daily feed intake increased with the level of cocoyam peels meal in the

diet, that is broilers on diets IV and V consumption was significantly (P<0.05) higher than

diet I but statistically similar with diets II and III. For feed conversation ratio result for diet 1 was comparable to broilers on diet III. Finally, considering the growth performance, diet II

(5%) is recommended.

Keywords: Taro cocoyam peels meal, growth performance, Lowman Brown broiler chicks

mailto:*[email protected]


(ISTRC-AB)

66

Effects of sodium meta-bisulphite and blanching pretreatments on the quality characteristics of yam bean (Pachyrhizus erosus) flour

Buckmanab, E.S., Odurob, I. N, Plahara, W.A. and Carey, E.c

aCSIR- Food Research Institute, P.O. Box M20, Accra, Ghana bKwame Nkrumah

University of Science and Technology, Kumasi, Ghana cInternational Potato

Center, c/o CSIR-Crop Research Institute, Kumasi, Ghana

Abstract

A study was undertaken to determine the effects of sodium meta-bisulhpite and blanching

pretreatments on the quality characteristics of yam bean (Pachyrhizus erosus) flour. The experimental design used was a 2 x 3 factorial design involving two factors of peeling

(peeling and non-peeling) and three pretreatments (blanching at 100æ%C for 3 min; soaking in 0.1% sodium meta-bisulphite solution for 3 min and no treatment. Samples were dried at

55ºC for 6 hours, cooled to room temperature, milled, sieved and packaged. Quality determinants used included ease of drying as indicated by the final moisture content, colour,

pH, and ease of milling as indicated by particle size distribution. Peeling with sodium meta-

bisulphite pretreatment produced whiter yam bean flour (L*-value of 90.89).Flour samples from unpeeled roots recorded lower pH (5.96) than those from peeled samples (6.65). The

combined effects of peeling and sodium meta-bisulphite or blanching pretreatment produced flours with desirable pH values ranging from 6.0 to 6.4. The blanched sample had higher

particle sizes distribution (50%>100um) compared to the control and sodium meta-bisulhpite treated flours (30>100um).Peeling, meta-bisulphite or blanching pretreatments did not affect

the rate of drying significantly. From the findings a standard procedure for yam bean flour

production was suggested to include peeling and sodium meta-bisulphite pretreatment.


(ISTRC-AB)

67

Some quality evaluation of fried snack from brewers’ spent cassava

and wheat flour

1*Omidiran, A. T., 1Sobukola, O.P., 2Sanni, S. A., 1Adebowale, A.A., 1Obadina,

O.A.,1Kajihausa, O.E., 3Adegunwa, M.O., 1Sanni, L.O., 4Tomlins, K, 5Wolfgang

Tosch 1Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria. 2Department of Nutrition and Dietetics, Federal University of Agriculture, Abeokuta, Nigeria.

3Department of Foodservice and Tourism, Federal University of Agriculture, Abeokuta, Nigeria. 4Natural Resources Institute, University of Greenwich, United Kingdom

5SABMiller PLC, Woking, Surrey, United Kingdom

* [email protected]

Abstract

This study investigated the effect of some processing parameters on some quality attributes of fried snack as well as optimization of the process. Response surface methodology based

on Box – Behnken design was used to study the effect of frying temperature (140 – 160 oC),

frying time (2 – 4 mins), level of brewers’ spent cassava flour (20 – 40%) and thickness (2 – 4 mm). Twenty nine experimental runs with four centre points were generated and samples

were analysed for expansion, texture, moisture, oil, colour parameters and change in colour intensity. Sensory evaluation of the optimized sample to determine its level of acceptability

based on texture, taste, aroma, oiliness and overall acceptability was carried out as well as comparison of the optimized sample with fried snack from 100% wheat flour. Data obtained

were subjected to statistical analysis (Design expert version 6.0). Expansion and lightness

parameter increases as frying temperature and time increases while texture, redness and yellowness decreases. Temperature had a significant (p< 0.05) negative effect on texture

while level of BSCF, thickness and the interaction between temperature and level of BSCF had a significant (p< 0.05) positive effect on texture. Based on desirability (0.771) concept,

the frying temperature of 140.11oC, frying time of 4 minutes, 32.09% level of BSCF and 2 mm thickness was chosen as the optimized processing conditions. Sensory analyses showed

a moderate degree of likeness for the optimized sample with 56% acceptability while it is

preferred in terms of texture and oiliness to fried snack prepared from 100% wheat flour at the same frying conditions. This study established that a fried snack can be developed from

the inclusion of BSCF, a safe waste product from cassava brewing process to wheat flour.

Key words: Brewers’ spent cassava flour, fried snack, optimization, colour parameters



(ISTRC-AB)

68

Process optimization for fufu production

M.U. Ukwuru 1 and J.I. Awah 2*

1Department of Food Science and Technology, Federal Polytechnic, Idah,

P.M.B. 1037, Idah, Kogi State, Nigeria. 2Cassava Programme, National Root Crops Research institute, Umudike,

P.M.B 7006 Umuahia Abia State, Nigeria.

*[email protected]

Abstract

Two varieties of cassava tubers; manihot palmata (Sweet variety) and manihot utilisima (Bitter variety) were processed into fufu to optimize their processing conditions. They were

peeled, washed, cut into small pieces and steeped in water for fufu production. Two techniques were used in processing of the cassava fufu. In one process, cassava fufu was produced

involving changing steeping water after, 48h before re-steeping for another 48h. Another

technique involved steeping of cassava tubers for 96h without changing the steep water. The fermentation was left for 96h after which the cassava was washed to obtain fufu. The

fermentation was examined for pH, total titratable acidity and cyanide detoxification. The fufu was evaluated for odour, flavour, texture, colour and overall acceptability. The pH

decreased from 8.11-7.6% for sweet cassava and 8.11-7.17 for bitter cassava. Titratable acidity and microbial load increased with increase in length of fermentation. There was a

reduction in HCN content of sweet cassava variety by 15.95% and 17.95% in bitter cassava variety. The reduction in bitter cassava was significantly higher compared with the sweet

cassava. The bitter cassava had the highest overall acceptability of sensory evaluation in

terms of odour, flavour, texture and colour. This indicates that the bitter cassava variety is more accepted for fufu production.

Key words: Sweet cassava, Bitter cassava, Cassava fufu, Fermentation, Optimization.



(ISTRC-AB)

69

Comparative Economic Analysis of Fortified and Non Fortified Cassava Peel in

Goat Feeding in Southwest Nigeria

Adetoye, A. M., Okojie, L. Adebayo, K. and Sanni. L. O.

Federal University of Agriculture, Abeokuta, Nigeria

[email protected]

Abstract

Nigeria produces up to 49metric tones of cassava annually and 90% of the produce is being consumed locally. Out of the entire tuber of cassava 15-20% is considered as waste (peels). In many processing enterprises, handling of cassava wastes (peels) can be a major challenge

involving significant costs. In the attempt to utilize cassava waste, cassava peels are usually

fed to goats (wet cassava peels contain cyanide that is poisonous to animals). The study compares the economic analysis of fortified cassava peel and dried cassava peel in Osun

and Ogun States. A multistage sampling technique was used to select respondents for the study. This involves the purposive selection of 2 zones from Agricultural Development

Programmes (ADP) zones in each of the states out of which 2 blocks were selected to make a total of 12 blocks in the two states. A collection of 10 goat farmers were selected in each

blocks to make a total of 60 goat farmers in each states and a total of 120 goat farmers in the

two states. In each of the selected 12 blocks, 5 cassavas processing centers were selected randomly and this made a total of 60 cassava processors in the two states. Primary data

from the study were obtained with the aid of structured questionnaire. Data collected were analyzed using descriptive statistics, benefit perceived index, Tobit and logit regression analyses,

empirical market potential formula and gross margin. The findings revealed that majority of goat farmers had no formal education (45.9%) The respondents weighted annual income in

the study ranged mainly below N25000 (52.29%), age between 51-60years (33.03%) and

were mostly (90.4%) married with the female folk constituting the majority (55.96%). Majority of cassava processors, had processing experience of 16-20years (42.1%), aged between 30-

40years, sex indicates both sexes are actively involved in cassava processing. Average quantity of cassava peels at processing centre/ per processing day in Osun and Ogun was estimated

to be 263kg and 247kg respectively. Level of education, marital status and system of goat keeping have a likelihood of increasing of benefit perceived in the use of fortified cassava

peel while age, level of education, marital status and farming system are the factors that

influence WTP for cassava peel based products. Overall WTP amount are N144.49 and N1,019 for dried cassava and fortified cassava peel respectively. Estimated market potential

for fortified cassava peels is N5883430.87 and that of dried cassava peel is N810307.14. Gross margin analysis shows a profit of N50 and N262.5 naira for dried cassava peel and

fortified cassava peel respectively. The study concluded that there exist a market potential for cassava peels based products and therefore suggests that creating market for cassava

peel based products will provide additional income for cassava processors and goat production

should be carried out by the farmers under an intensive system.



(ISTRC-AB)

70

Biologic and digestibility coefficient effect of including different levels of

composite cassava meal in weaner rabbits diet

Ekwe 1, C.C.; Ukachukwu2, S.N.; Odoemenam3, V. and Ekwe 1, K.C.

National Root Crops Research Institute, Umudike

Michael Okpara University of Agriculture, Umudike. Coll. of Anim. Sci. and Anim. Prod.

Federal University of Technology, Owerri. Dept. of Anim. Sci.

Abstract

An experiment was conducted to evaluate the effect of composite cassava meal (CCM) on the growth performance and digestibility coefficient of weaner rabbits. The rabbits were fed

with formulated diets containing CCM at 0%, 10%, 20% and 30% levels of replacement. The experiment was arranged in a completely randomized design replicated 3times and each

rabbit represented a replicate. The rabbits averaging 6-8 weeks were fed ad-libitum throughout the rearing period of 84 days. Treatment 4(30%) encouraged better performance (P<0.05)

of the rabbits in terms of their final weight (2.34kg), growth rate (15.71g/day) and feed

conversion ratio (2.58) than the other two experimental and control diets. Performance of rabbits on treatments 2, 3 and 4 were statistically the same as the rabbits on control treatment

in all the growth parameters investigated, except average daily feed intake which were significantly different (P<0.05) among the treatments. Rabbits in treatment 4 consumed the

highest quantity of feed (40.62g) which could be attributed to the higher level of fibre in the diet. Treatment 4 also encouraged better digestibility coefficient for dry matter (78.57%)

and crude protein (85.50%) than other treatments which could be due to crude protein content of the diet. Replacement level up to 30% should therefore be encouraged.


(ISTRC-AB)

71

Quality attributes of gari produced from cassava substituted with cocoyam (colocasia esculenta) tuber

Ade-Omowaye, B.I.O., Olatunde, S.T. and Akinwande, B.A.

Department of Food Science and Engineering, Ladoke Akintola University of Technology, P. M.

B. 4000, Ogbomoso, Oyo state. Nigeria.

[email protected],

Abstract

Dependence on a few crops has been observed to have negative consequences on ecosystems, food diversity and human health. In addition neglected and underutilized species could play a significant role in the fight against hunger and serve as a key resource for agriculture and

rural development. Cocoyam, an underutilized tuber in Nigeria was studied for its potential in

gari making to reduce dependence on cassava conventionally used for this product. Gari was produced from cassava substituted with varying proportions (0, 10, 20, 30, 50 and 100%) of

cocoyam tubers and the proximate components, some chemical composition and physicochemical properties of the gari produced were evaluated. Sensory attributes of the

gari samples were also assessed. The moisture content of all the gari samples were generally below 8 % indicating safe level for prolonged storage. Substituting cassava with

cocoyam at varying proportions resulted in 8–26 % reduction in fiber content, 8-49 % and 7-

183 % enhancement in ash and protein contents, respectively. Cassava substitution with cocoyam significantly (p<0.05) increased pH level and reduced total titratable acidity of the

gari samples. There were wide variations in the hydrogen cyanide (HCN) contents of the gari samples with gari produced from 100 % cocoyam mash having the lowest value of 0.24

%, and 100 % cassava gari had the highest value of 14.22gm/kg. A progressive decrease in the swelling capacity was observed with increase in the substitution level of cocoyam in the

mixture. The results of water absorption capacity, reconstitution index, syneresis and bulk

density of the samples followed similar trend with that of swelling capacity. The panelists consistently rated 100% cassava gari best in terms of colour and overall acceptability. However,

the colour rating of gari obtained from cassava mash substituted with 20% cocoyam and those produced from 100% cocoyam, were similar to gari from 100% cassava. Similarly, in

terms of overall acceptability, there was no statistical difference (p<0.05) between gari produced from 100% cocoyam and 100 % cassava indicating the potentials of these tubers in

gari making.



(ISTRC-AB)

72

Quality indices of cassava starch as affected by variety and maturity age

1*Adegoke, Adekola and 2Adekoyeni, Oludare

1Production and Engineering Department, Psaltry International Limited, Alaide/Wasinmi

Village, Ado Awaye, Oyo State, Nigeria 2Food Science and Technology Department, The Bells University o f Technology, Ota,

Ogun State, Nigeria

*[email protected]

Abstract

Cassava (Manihot esculenta) is of varying usage globally. In Nigeria, it is processed into staple foods such as gari, fufu, flour, starch, and of recent glucose syrup. In this study, four varieties of freshly harvested cassava roots (TME 419, TMS 0068, TMS 326, TMS 30572)

at maturity age (8-12) months were peeled by abrasion, washed, chopped and rasped. The

starch content of TME 419, TMS 0068, TMS 326, TMS 30572 roots were 21-30% and dry matter was 26-35.1% at age 8-12 months. The rasped roots were mixed with a lot of membrane

treated water. The resultant slurry was extracted, refined, vacuum pressed and flash dried at 700 C. The dried starch was sifted and kept in air tight containers for analysis. The quality

indices determined were moisture content (11-12%), degree of whiteness (82-88Wb), starch content (21-30%), Baume (21-22ÚBe) and pH (6-7). Engineering properties which include

density, specific heat capacity, thermal conductivity, thermal diffusivity, WAC, amylose/

amylopectin ratio of cassava starch were investigated using proximate composition based empirical models and Juliano methods. From the data obtained, it was found that density of

cassava starch is (526±0.10) Kg/m3, specific heat capacity (942±0.05) (KJ/Kg K), thermal conductivity (0.12±0.02)W/mÚK, thermal diffusivity (2.42x10-7±0.01)m2/s, Peak viscosity

(290.58±0.01)Ns/m2, setback viscosity (179.58±0.03) Ns/m2, amylose/amylopectin ratio (0.36±0.01), SP (6.83±0.03)%, WAC (94.49±0.04)% and SI (6.83±0.03). The values obtained

for thermophysical and rheological properties were found to be useful in the design of extraction and refining process for cassava starch while the quality indices determines the consumers’

acceptability of cassava starch.

Keywords: Engineering properties, sift, rasp and quality indices.



(ISTRC-AB)

73

Effect Of Different Packaging Materials And Storage Conditions On The

Nutritional Composition Of Dried Mushroom From Cassava Peels

*+Ajayi, O.A., *Obadina, A.O., **Adegunwa, M.O., *Sobukola, O.P.,

*Adebowale, A.A., Omemu, A. M., ***Asagbra, Y., ***Akinyemi Akinrinola, O.

A., ***Asiru, W., *Sanni, L.O. and ****Tomlin Keith *Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta. Nigeria

**Department of Foodservice and Tourism, Federal University of Agriculture,

P.M.B. 224 0, Abeokuta. Nigeria

***Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria

****Natural Research Institute, University of Greenwich, Kent, Chatham, United Kingdom

Corresponding author: [email protected]

Abstract

This research reports the effect of packaging and storage conditions on the nutritional

composition of mushroom from cassava peels. Peels of cassava were used in the cultivation of mushroom Pleutorus ostreatus and dried using cabinet dryer at different drying

temperatures (400C, 500C, 600C) for 8 hours. The dried mushroom was packaged in four different packaging materials which included high density polyethylene (HDPE), polypropylene,

laminated aluminium foil and vacuum packaging and stored at different storage conditions which included ambient, refrigeration and freezing temperatures for 12 weeks. Samples

were collected at 2 weeks intervals for proximate, mineral and some vitamins analyses.

Mushroom in HDPE stored at ambient temperature showed significant reduction of 14.25%, 1.27%, 1.16% and 2.07% in carbohydrate, protein, fat and fibre respectively after 12 weeks

of storage. Mushroom in polypropylene packaging material at refrigeration temperature showed reduction of 13.29%, 1.74%, 1.70%, 2.23%, 1.85% and 2.44% in carbohydrate,

protein, fat, fibre and ash respectively for the 12 weeks storage period. Mushroom in laminated aluminium foil showed reduction of 9.2%, 2.26% and 2.07 % in carbohydrate, protein and fat

respectively over the period of 12 weeks. In vacuum packaging material, at ambient

temperature the carbohydrate, protein, fat, fibre, ash and moisture reduces by 6.2%, 0.85%, 0.33%, 0.44%, 0.46% and1.09% respectively with the highest retention capacity. Vacuum

packaging material at freezing temperature showed a reduction of 2.41%, 0.79%, 0.86%, 0.45%, 1.34% and 0.47% in carbohydrate, protein, fat, fibre and ash respectively. This study

showed that vacuum packaged dried mushroom stored under refrigeration temperature gave the optimal nutrient retention which increases the shelf-life and availability in the market.

Keywords: Dried mushroom, vacuum packaging, carbohydrate, fat, vitamin



(ISTRC-AB)

74

Proximate and sensory evaluation of different cooking methods of edible aerial yam (dioscorea bulbifera)

Ofoeze M.A1* and Adeoye-Agomoh Q.C2

1National Root Crops Research Institute Umudike PMB 7006 Umuahia, Abia State Nigeria 2Home and Rural Economics Department Federal College of Agriculture Ishiagu Ebonyi State

*[email protected]

Abstract

Aerial yam (D. bulbifera) is among the nine varieties of yam cultivated in Nigeria but less consumed by the people as it is popularly regarded as food for the low income dwellers. The

yam is popularly eaten by just boiling and taken with palm oil. The aim of this work is to

evaluate the proximate composition and acceptability of different cooking methods of this yam specie. The aerial yam used was obtained from the yam barn of the NRCRI Umudike.

The lots were cleaned and divided into five. The first was peeled and boiled for 45 minutes (BB); the second was boiled with the peel for 55 minutes (BP). The third was peeled sliced

and fried into chips for 15 minutes (FY), the fourth was roasted in an open local charcoal fire (RT). The last was boiled for 15 minutes baked in an oven for 20 minutes at 65oC (BK). The

result of the proximate composition showed that the moisture contents of the fresh samples

ranged from 72.36% to 65.82% with BB highest and FY lowest. Crude Protein was between 17.52 to 13.69 with BB having the lowest and BP the highest. Just like most yams, all except

FY which had 8.33% was low in fat. This was attributed to frying with oil. For Carbohydrates, BB 82.35% was the highest and FY 65.63% the lowest. There were significant differences

in ash and crude fibre. The sensory evaluation showed that BB ranked highest in colour, RT and FY highest in taste. All these methods were generally accepted with FY as most accepted.

Key words: Aerial yam, cooking, proximate composition and sensory evaluation.



(ISTRC-AB)

75

Sensory evaluation and consumer acceptability of sweetpotato genotypes by

youths in Omu Aran, Kwara state, Nigeria

*Afolabi, M. S.1, Carey, E. E.2, Ogunjimi S . I3, Akoroda, M. O.4

1Department of Crop and Soil Science, Landmark University, Omu Aran , Kwara State, Nigeria.

*corresponding author,[email protected] 2CIP c/o CSIR-CRI, Kumasi Ghana. e [email protected]

3Department of Agricultural Economics and Agricultural Extension, Landmark University, Omu

Aran , Kwara State, Nigeria. [email protected] 4Department of Agronomy, University of Ibadan, Nigeria. [email protected]

Abstract

The purpose of this study was to evaluate consumer’s acceptability of four orange-flesh sweetpotato genotypes (440034, 199024.2, Blesbok and 199034.1) and seven yellow-fleshed genotypes (W-151, Ex-igbaran, Shaba, NASPOT5, Barth, 440215 and Sauti) newly introduced

to Omu-Aran community. Youths between 17 and 25 years of age in Landmark University,

Omu Aran, Kwara State, were selected for this purpose. These genotypes were germplasm collection of the Department of Agronomy, University of Ibadan. All respondents (26 males

and 16 females) were selected on the basis of their awareness and consumption of sweetpotato. Harvested sweetpotatoes of various genotypes were boiled two days after

harvesting and each of the sweetpotato variety was sliced and served. All the genotypes were cooked at once and polythene bags were used to pack them in the cooking pot. Water

was used to rinse their mouths before proceeding to another genotype. The attributes evaluated

include sweetness, consistency, texture and acceptability. Data analysis was carried out using frequency counts, percentage, mean, standard deviation and correlation. Blesbok and

440034 of orange flesh were highly consistent, moderately sweet and the texture was highly acceptable, while 199034.1 was the least fibrous among the genotypes. Comparing the scores

of the all varieties presented for sensory evaluation, the preferred variety in terms of consumer acceptability was Blesbok. Conclusively, youths in Omu-Aran, Kwara State, Nigeria prefered

Blesbok above all other varieties because of its colour, sweetness, consistence and low

fibre. It is recommended that policy makers, research institutes and Non-Governmental Organisations should intensify efforts towards the propagation of this variety by ensuring its

massive disemination to farmers by extension agents.

Keywords: Acceptability. consistence, genotype, propagation, sweet-potato, sweetness, texture.






(ISTRC-AB)

76

NUTRITIONAL COMPOSITION AND SENSORY ACCEPTAB ILITY OF SAUSAGE ROLL AND MEAT

PIE FROM HIGH QUALITY CASSAVA FLOUR

Akinlonu, E.O. and Sanni, S.A.

Department of Nutrition and Dietetics

Federal University of Agriculture, PMB 2240, Abeokuta, Nigeria

[email protected]

Abstract

This study investigated the nnutritional composition and sensory acceptability of sausage roll

and meat pie from high quality cassava flour (HQCF). High quality cassava flour was purchased from Peak Products industry in Abeokuta. The flour was used in the production of

sausage roll and meat pie with other ingredients. Proximate, mineral and cyanide composition of the products were determined using Standard Analytical Procedures. The sensory

acceptability of the sausage roll and meat pie were evaluated in terms of colour, texture, taste, flavour and general acceptability using a nine-point hedonic scale. The Proximate

composition showed that there was no significant difference (Pe”0.05) in the in the proximate

composition of the samples except ash. However, the iron, zinc, calcium and sodium contents were significantly different (d”0.05). Gross energy was highest in HQCF sausage roll

(419.07%). The cyanide composition of the products was between (0.95-1.04 mg/100g) which is lower than the acceptable limit by Codex Standard. Sensory acceptance scores

showed that all the products were generally acceptable and there was no significant difference (Pe”0.05) in all the attributes evaluated except texture. The results from this study showed

that nutritious, safe and organoleptically acceptable sausage roll and meat pie could be obtained

from HQCF.

Keywords: sausage roll, meat pie, high quality cassava flour, proximate, mineral, sensory acceptability.




(ISTRC-AB)

77

Recipes from low dry matter orange fleshed sweetpotato for Ghanaian

households

Eric Kuuna Dery1, Eric Owusu Mensah1, Sarah Afi Koryoe 2

and Edward E. Carey1

1 International Potato center (CIP-SASHA GHANA

2 Kwame Nkrumah University o f Science and Technology (KNUST) - Kumasi

[email protected], [email protected], [email protected]

Abstract:

Vitamin A deficiency (VAD) is a widespread health challenge in sub-Saharan Africa(SSA) and one simple way of combating this disease is through the eating of vitamin A incorporated

crops. Orange fleshed sweetpotato (OFSP) has recently been disseminated for its high vitamin

A content. Most households in Ghana however do not patronize sweet potatoes due to the lack of knowledge on the various ways of preparing them. In this paper, various recipes were

developed from low dry matter OFSP roots and leaves in order to demonstrate to consumers that sweetpotatoes can be eaten in different forms. Fresh and wholesome roots and leaves

of Apomuden (orange flesh sweet potato) were selected for the recipes. Flour was produced from roots to prepare porridge and pastries like scones, meat ball, meat pie and spring rolls.

Sweetpotato chips, juice and “mpotompoto” were also produced from the raw roots. Leaves

were used for palaver sauce, okro soup and dried leaf soup. A total of 50 people (5 for the leave sauce and soups, 5 for the porridge and “mpotompoto” and 40 for the pastries and

juice) were made to taste samples, give their overall acceptabilit y and suggest recommendations. At the end of the exercise, all products were accepted by the respective

consumers. It can be concluded that,delicious and nutritious products can be developed from low dry matter sweetpotato for the Ghanaian households in order to induce themto adopt

OFSP

Key words: Recipies, Apomuden, vitamin A, sweepotatoes, pastries,







(ISTRC-AB)

78

Design and performance evaluation of an agricultural waste-heated cabinet dryer

for cassava processing

Alenkhe, B., Randriamorasata, J., Msangi, M., Ranaivoson, R., Andrianavalona,

V., Kolawole, P. and Abass, A.

Abstract

Drying of food products, especially during the raining seasons, remains a challenge to processors in Africa. Processors rely on sun-drying for the bulk of drying of food products. Sun-drying

is slow and unreliable, leads to inconsistent product quality and low product outputs. The use

of cabinet dryers is well known but their use is hindered by limited sources of energy which are mostly uneconomical for resource poor farmers due to the high costs. To resolve this

problem for cassava, a cabinet dryer heated with agricultural wastes such as saw dust, palm kernel shell and cashew nut shells was designed. Two prototype dryers were fabricated and

tested in Tanzania and Madagascar. The dryer in Tanzania has a drying-chamber of 2.5m in length x 2.5m breadth x 2.5m in height, the false walls are made of mild steel with a lagged

outside cover. Cassava grits on aluminum trays are dried with forced hot air. The hot air is

generated with the aid of a fire box that acts as a gasifier and a heat exchanger. Preliminary test results showed that the drier uses 16kg of saw dust to dry 80kg of cassava grits of 45%

m.c to 12% m.c. in 6 hours at hot air temperature range of 45-75°C. The dried grits are white but require testing for food quality characteristics.


(ISTRC-AB)

79

Pre-storage curing and Nanobiotechnology treatments on fresh yam (Dioscorea

rotundata) tuber in storage

1Eze, S. C.,1 S. I Umeh.,1 E. I. Eze., 1K. I. Ugwuoke, 2P. I. Ezeaku

1Department of Crop Science, University of Nigeria, Nsukka 2Department of Soil Science, University of Nigeria, Nsukka

Abstract

Postharvest losses of fresh yam tuber in storage remain a major problem amongst the yam growers and dealers. A 3 x 7 factorial experiment was conducted at the plant pathology laboratory of the University of Nigeria, Nsukka to investigate the effects of curing as a pre-

storage treatment and a combination of silver nitrate and neem leave extracts (silver neem)

on yam tuber in storage. The treatments comprised 3 levelsof silver neem solution thus:

28.40, 48.80 .8073.20 mg/mland curing ranged from S –S where the subscripts 0, 1, 2, 3, 4, 0 6

5, 6represents the seven groups of the tubers that were being exposed to the sun daily until the last group which was removed on the 6th day. After curing, each group was dipped in the 3 levels of silver neem solution and air dried. They were then stacked in the barn for observation

and measurements. A combination of 4 days curing with dipping the tubers in 48.80 mg/ml of silver neem solution significantly (P d” 0.05) increased the dormancy period of yams. Curing

beyond 4 days induced multiple sprouts on the tuber and significantly (P d” 0.05) increased weight loss. It is evident in this study that 4 days curing with or without the other treatments

is the optimum for effective storability of fresh yam tubers.

Key words: Fresh yam, Curing, Storage, Nanobiotechnology, Barn


(ISTRC-AB)

80

Haematological and serum biochemical indices of japanese quails (Coturnix

coturnix japonica) fed cassava grit as replacement for maize with or without â-

glucanase

1Amosun A.Y., 2Oyelami B. A., 1Abu O. A. and 1Tewe O.O

1Department of Animal Science, University of Ibadan 2Department of Agricultural Extension and Management, Federal College of Forestry, Ibadan,

Oyo State Nigeria

Abstract

One hundred and eighty (180) unsexed growing Japanese quails (Coturnix coturnix japonica) were used in a feeding trial to investigate the response of Japanese quails to replacement of

maize with cassava grit with or without â-glucanase supplementation. Birds were randomly grouped into six treatments in three replicates of ten birds per replicate.

Diet 1 was the control without cassava grit while diets 2 and 3 had 25 and 50% of their maize content replaced with cassava grit respectively. Treatments 4, 5 and 6 were the same as

treatments 1, 2 and 3 respectively but with â-glucanase added at 100mg/kg. Feed and water were supplied ad libitum throughout the period of study. Among the haematological parameter

monitored RBC (4.46x106/UI) and WBC (26.52x103/UI) were significantly (p< 0.05) affected

by dietary treatments. Thiocynate, AST (290.6 U.I/I) and ALT (33.6 U.I/I) were significantly (p< 0.05) influenced by the experimental diets. Replacement of 25-50% maize with cassava

grit in Japanese quail diets did not have negative effect on haematology and serum biochemistry of the birds.

Keywords: Cassava grit, â-glucanase, Japanese quail, Haematological and serum indices


(ISTRC-AB)

81

Glycemic index and glycemic load values of three Ivorian mixed meal foods in

healthy subjects

Camille A. Kouame 1, Nestor K. Kouassi1, Denis Y. N’dri1, Georges G. Tiahou2,

Georges N. Amani1

1 Laboratory of Biochemical and Technology of Tropical Products, Faculty of Foods Sciences

and Technologies, Nangui Abrogoua University, Abidjan, Cote d’Ivoire.

E-mail: [email protected] 2 Laboratory of Medical Biochemical, Faculty of Medical Sciences, Houphouet Boigny

University, Abidjan, Cote d’Ivoire.

[email protected]

Abstract

Though the glycemic index (GI) of common food items has been determined, the GI of the popularly processed and commonly consumed foods in Cote d’Ivoire is not known. The main

objective was to determine the blood glucose response and GI/GL of foods in vivo of three

Ivorian meals. Three different meals with similar levels of carbohydrates were assayed in ten normal subjects and blood samples were obtained at 0, 15, 30, 45, 60, 90 and 120 mn to

determine glucose levels. The meals showed different GI: rice based meal had lower values (mean value 45.18) and the higher GI was shown by the yam tuber and cassava tuber based

meal (93.78 and 85.62 respectively).Their respective glycemic loads (GL) (mean ± s.e.m; 46.89 ± 1.92 g; 42.81 ± 0.69 g and 22.59 ± 1.54 g) are all also significantly different with the

threshold from 5%. The comparison of GI of this mixed meals showed differences of clinical importance and could form a basis for dietary advice to diabetic subject.

Key words: Blood glucose response, Glycemic index, Glycemic load, Ivorian meals




(ISTRC-AB)

82

Assessment of the antioxidant potential of sweetpotato peel extract

in controlling rancidity

Owusu-Ankomah, O.1, Oduro, I.2, Akwettey, W. 3

[email protected] [email protected]

[email protected] m3

Abstract The increasing preference of consumers for natural food additives has spurred growing

interests in the replacement of synthetic food antioxidants with natural ones in controlling rancidity. This has fostered research into screening of raw materials to identify new effective

sources of antioxidants. In this study, the phytochemical constituents and antioxidant activity of 5 varieties of sweetpotato peel (SPP) were investigated. All 5 SPP samples tested positive

for saponins, tannins, glycosides, flavonoids and triterpenoids whilst anthraquinones, sterols, alkaloids and cyanogenetic glycosides were absent. “Jitihadda” recorded the highest

((95.026±2.08%) DPPH radical scavenging abilities, followed by “Faara” (94.799± 0.39%),

synthetic antioxidant BHT (94.372 ± 0.11%), “blue blue” (77.958± 2.03%), TIS9265/10 (60.206± 0.25%) and “Santom pona” (26.949± 2.49%) with non-significant differences being

recorded among “Jitihadda”, “Faara” and BHT. Jitihadda peel was selected for rancidity studies with lard as substrate because it recorded the highest antioxidant activity among the

5 SPP. As an indication of the progress of rancidity, peroxide value (PV) and free fatty acid (FFA) values increased whilst pH levels decreased with time for all concentrations (200, 400

and 600ppm) of “Jitihadda” peel extract after application to lard and storage at refrigeration

(5ºC) and room temperature (29ºC) for 120 hours. A concentration of 600ppm Jitihadda peel extract (SPP600) was found to be more effective in delaying rancidity in lard as indicated by

the lower PV and FFA values recorded with time compared to the other concentrations. The antioxidant activity of SPP600was comparable to the commonly used synthetic antioxidant

BHT (200ppm) and had the potential of controlling rancidity in lard.





(ISTRC-AB)

83

Influence of the variety and cooking method on Glycemic Index of yam

Nestor Kouakou Kouassi1), Georges Gnomblesson Tiahou2

and Georges N’Guessan Amani1

1-Laboratory of Biochemical and Technology of Tropical Products,

Faculty of Foods Sciences and

Technologies, University of Nangui Abrogoua, Abidjan, Cote d’Ivoire 2-Laboratory of Medical Biochemical, Faculty o f Medical Sciences, University of Cocody,

Abidjan, Cote d’Ivoire


Abstract The aim of the study was to evaluate the impact of variety and cooking method on glycemic index of yams consumed in Cote d’Ivoire. On different occasions, human volunteers consumed 50 g of available carbohydrate in yams varieties cooked either in boiled water or in a

conventional oven after 10-12 h overnight fast. The glycemic index values were calculated

after measured venous-blood glucose before and after ingestion at 0, 15, 30, 45, 60, 90 and 120 min. The GI results showed that in each specie of yams, the glycemic index does not

vary whatever the cooking method. But, considering the yam specie, the glycemic index values varied significantly depending on the variety and cooking method used. The comparison

of glycemic index of yams varieties showed differences of clinical importance and could form a basis for dietary advice to diabetic subjects.

Key words: Yam, specie, variety, cooking method, glycemic index






(ISTRC-AB)

84

Microbial and quality assessment of fresh mushroom (pleurotus ostreatus)

from cassava peels

*Olotu I, O., *+Obadina, A.O., *Adegunwa, M.O., *Sobukola, O.P., *Adebowale,

A.A., **Asagbra, Y., AkinyemiAkinrinola, O. A., Asiru, W., *Sanni, L.O. and

***Tomlin Keith *Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta. Nigeria

**Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria

***Natural Research Institute, University of Greenwich, Kent, Chatham, United Kingdom

[email protected]

Abstract

The cultivation of mushroom from cassava peels is a feasible technology for converting waste to wealth. With the aim of extending knowledge on the quality and microbial safety of

mushroom, Pleurotus ostreatus grown on cassava peels were examined to assess its microbial population, colour (lightness, redness, yellowness) and texture (firmness) in this study.

Neither Listeria monocyto genes nor Salmonella spp was recovered from the fresh mushroom. The total aerobic, Bacillus spp, Staphylococcus spp, total coliform, yeast, mould

and Pseudomonas spp count were 2.30 log cfu/g, 1.77 log cfu/g, 0.89 log cfu/g, 0.85 log cfu/ g, 1.74 log cfu/g, 1.68 log cfu/g, 1.00 log cfu/g respectively. Bacillus spp had the highest

percentage occurrence (29.5%) of the bacteria in the fresh mushroom, while the coliforms

had the lowest (3.00%). The fresh mushroom was found to be satisfactory when compared to the microbiological criteria of ready to eat foods (RTE). Fresh Pleurotus ostreatus grown

on cassava peels had lightness value of 95, yellowness value of 2.4 and redness value of -2 based on the Hunters lab colour scale and a firmness of 10.00N. This study shows that safe

and good quality mushroom can be successfully cultivated on cassava peels.

Key words: Mushroom, Pseudomonas spp, colour, texture, cassava peels.



(ISTRC-AB)

85

Retention of â-carotene in cream-fleshed sweetpotato-based complementary food

stored in different containers under simulated tropical temperature and humidity

Francis Kweku Amagloh1,2*, Louise Brough2, Janet L. Weber2, Anthony N.

Mutukumira2, Allan Hardacre 2, Jane Coad2

1Departmentof Biotechnology, Faculty of Agriculture, University for Development Studies,

Nyankpala, Ghana; 2Institute of Food, Nutrition and Human Health, College of Health, Massey University,

Palmerston North, New Zealand

[email protected];

Abstract

The stability of â–carotene in cream-fleshed sweetpotato-based complementary food stored in three different containers under simulated tropical temperature of 32°C and 85% relative humidity in an environmental chamber for 24 weeks was investigated. The formulation stored

in a metallised polyester film in a refrigerator (approximately 3.0°C and 95% relative humidity)

retained about 81% of â–carotene at week 24, with no significant change in the moisture content. The formulation stored in either a metallised polyester film or a translucent

polypropylene container placed in the environmental chamber retained approximately half of the â–carotene at week 24, with a slight increase in moisture content. However, the formulation

held in a transparent low-density polyethylene bag had the lowest â–carotene retention (37%) and the highest moisture content at week 24. Within the limits of this study, it has been

demonstrated that â–carotene in cream-fleshed sweetpotato-based complementary food was

well retained when moisture uptake was minimised.

Key words: â-carotene, complementary food, storage, sweetpotato



(ISTRC-AB)

86

Performance of (Pleurotus pulmonarius) on Cassava (Manihot esculenta) peels and

Cassava Stalk Under Supplementation With Palm Kernel Cake (PKC)

Agnes, E. Asagbra1., Akinyemi-Akinrinola, O. A.1, Wahab. B. Asiru2, Lateef, O

Sanni, 3 Gloria N Elemo 4, Anton Sonnenberg5 Tomlins, I. Keith6

1 Department of Biotechnology, Federal Institute of Industrial Research Oshodi, Lagos, Nigeria 2Department of Pro ject Development and Design, Federal Institute of Industrial Research

Oshodi, Lagos, Nigeria 3Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria 4 Federal Institute of Industrial Research Oshodi, Lagos, Nigeria

5Mushroom Research, Plant Breeding Wageningen University and Research Center,

The Netherlands.

6Natural Resources Institute, Kent, Chatham Maritime, UK

* [email protected]

Abstract Oyster mushrooms (Pleurotus pulmonarius) are saprophytes as they obtain their nutrients

from various decomposing organic materials. Being saprophytic, mushrooms produce a variety of lingo cellulolytic enzymes that help them convert cellulose and lignin into useful carbohydrates

such as glucose, which becomes readily available to the fungi as an energy source. There have been different substrates that have been identified and utilized for cultivation of mushrooms

such as cotton waste, rice straw, saw dust, groundnut shells and even corncob. Most of these wastes are low-value lignin celluose that have been derived from agro-industrial processes.

Pleurotus species are the third among the world’s most cultivated mushrooms. Pleurotus pulmonarius was cultivated on Manihot esculenta peels, stalk and PKC at different

percentages. The study was carried out to test the possibilities of using cassava peels, stalks

and to determine the effect of additives on the performance of the fungus on the substrates. The research started with different steps, media production, development of spawn, substrate

preparation, vegetative phase, mushroom fruiting and harvesting. The experiment was in five sets; One set was using cassava peels alone, cassava stalk alone, cassava and stalk

combination, cassava peels and PKC, cassava stalk and PKC. The data obtained were subjected to analysis of variance (ANOVA). Test of significance were carried out using

Duncan multiple range test at P<0.05. The cassava stalk (80%) + cassava peels (20%) had

primordial appearance in 6days, cassava stalk alone at 28days and cassava peels alone 15days. The biological efficiency of cassava peels was 8.9%, cassava stalks was 13.1%

while cassava peels and cassava stalk with the addition of PKC increased the biological efficiency from 34.0% to 48%. The results of this study shows that the mushroom Pleurotus

pulmonarius exhibited an increase in performance with increased additive (PKC), 20% inclusion level is the most efficient.



(ISTRC-AB)

87

Sensory evaluation and consumer acceptability of orange-fleshed sweetpotato by

pregnant women and children under2 years in Western Kenya

1Oyunga-Ogubi, M A, 2Cornelia Loechl, 2Hermann Quedraogo, 2Jan Low

1Kenya Agriculture Research Institute, Kibos, P.O Box 1490-40100, 2International Potato Centre (CIP), Nairobi, Kenya [email protected],


Abstract

The study purpose was to evaluate how two new high â-carotene sweetpotato varieties, Vita and Kabode were assessed against local checks by pregnant women and how young children

under 2 years liked them in Bungoma and Busia districts of Kenya. Sensory profiles were

determined using pregnant mothers (n = 79) and children below 2 yrs (n = 72). Mothers gave acceptability scores for how they perceived their children’s acceptance. Attributes assessed

were; flesh colour, root texture ranging from very watery to very dry, fibrousness of root, taste/flavor, and overall opinion on the acceptability of the varieties Results: Attractiveness

of flesh color, in Bungoma the scores of the three varieties were very close, whereas in Busia the local check was scored highest. The acceptance of the root texture of the local

check in the two districts was higher than of the two new varieties (local check: 4.00, Kabode:

3.27, Vita: 3.00). For the local check and Kabode these differences indicated statistically significant difference (local check) Kabode: p=0.002). Fibrousnesses level by district showed

statistically significance difference (p=0.018). Comparing the scores of the three varieties per district, in Bungoma the preferred variety in terms of taste/flavor was Kabode, followed

by the local check and Vita. In Busia, it was the local check, followed by Vita and then Kabode with the scores of the latter two being close together. Overall all three varieties

were acceptable to pregnant women since the average scores were higher than 3 (local

check: 4.13, Vita: 3.23, Kabode: 3.52). Children liked all the varieties.

Keywords: sweetpotato; Ipomea batatas; â-carotene; vitamin A; sensory evaluation;

consumer acceptability








(ISTRC-AB)

88

Effects of extrusion conditions on the functional properties of extruded snack

from brewers spent cassava and wheat flour

1*Hamed, L.O., 1Sobukola, O.P., 1Obadina, O.A., 1Adebowale, A.A., 1Kajihausa,

O.E., 2Adegunwa, M.O., 1Sanni, L.O., 3Tomlins, K, 4Wolfgang Tosch 1Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria. 2Department of Foodservice and Tourism, Federal University of Agriculture, Abeokuta, Nigeria.

3Natural Resources Institute, University of Greenwich, United Kingdom 4SABMiller PLC, Woking, Surrey, United Kingdom

* [email protected]

Abstract

Blends of brewers spent cassava (BSCF) and wheat flour were processed in a single screw extruder to obtain an acceptable extruded snack product. Response surface methodology based on Box-Behnken design was used to determine the effect of screw speed (80 – 120

rpm), barrel temperature (70 -90 0C), feed moisture (41.63 – 46.91%) and BSCF level (10 –

30%) on the functional properties of extrudates. Twenty nine experimental runs including five replicates of the central point were performed in random order. Blended samples were

subjected to analysis to determine effect of these experimental conditions on water absorption index (WAI), water solubility index (WSI), bulk density, breaking strength(BS) and lateral

expansion. The WAI ranges from 1.737 – 3.937, WSI ranges from 10.24 – 17.11%, lateral expansion ranges from 0.043 – 0.11, bulk density ranges from 0.62 – 1.15 g/cm3 and BS

ranges from 0.031 – 0.073 N/mm. The independent variables barrel temperature, screw

speed and BSCF level have significant (p<0.05) effect on WAI. Barrel temperature has significant (p< 0.05) effect on the bulk density while all the four independent variables (barrel

temperature, screw speed, feed moisture and BSCF level) have significant (p<0.05) effect on the WSI. The breaking strength of the extrudates was significantly (p<0.05) affected by

barrel temperature and feed moisture. Barrel temperature, screw speed and feed moisture have significant (p<0.05) effect on the lateral expansion .The optimum conditions for

processing of extrudates based on desirability (0.506) concept were found to be barrel

temperature of 79 0C, screw speed 80 rpm, feed moisture 41.63% and BSCF level of 15.73%.

Keywords: Brewers spent cassava flour, extrudates, functional properties, extrusion



(ISTRC-AB)

89

Comparative Value Addition for Improved RTB Entrepreneurship: A Case of

OFSP in SSA – Nigeria, Tanzania and Mozambique

Frank Ojwang,

f.o [email protected]

International Potato Centre

Abstract

OFSP is increasingly receiving cognitive responses from world leaders, with recent remarks from President Obama and Premier Cameron acknowledging the value of OFSP. Value

addition has not been fully exploited to make optimal revenue through OFSP. My idea is

aimed to enhancing value addition from the very basic value addition activities such as washing the roots to increase the selling price of OFSP. My scope is in Kwara State, Nigeria (for

West Africa), Morogoro, Tanzania (for Eastern Africa) and Maputo, Mozambique (for Southern Africa). Capacity building efforts and facilitating learning among extension workers and

farmers has focused sharply on value addition to increase revenue generated through OFSP. The simplest value addition promoted has been the washing of roots and basic packaging in

plain paper bags which increased revenue of the farmers by between 10-25% which we

verified using simple analytical methods together with the farmer. This worked in all the 3 countries. There is an average increment of $10-$25 per 180Kg sack in all the 3 countries.

President Obama described the sweetpotato as a super-duper sweetpotato. OFSP has an overwhelming demand that may not be satisfied by large and small-scale farmers in the 3

countries of focus alone. This means, OFSP has the potential to transform the lives of small- scale farmers and empower them economically. Cultivation of clean OFSP vines is the first

step to receiving desirable yields. Value addition is the game-changer for OFSP farmers

with every value addition process increasing the selling price.



(ISTRC-AB)

90

Functional properties and sensory quality of fermented cocoyam (xanthosoma sagittifolium) flour and its cooked paste

Ayano, A.E.1, Idowu, M.A.2, Shittu, T.A.2,Oguntonna, C. R. B3

1Central Teaching and Research Laboratory, Bells University of Technology, Ota 2Department of Food Science and Technology, Federal University of Technology, Abeokuta

3Department of Nutrition and Dietetics, Federal University of Technology, Abeokuta

[email protected] (Presenting author), [email protected], [email protected],

[email protected]

Abstract

Cocoyam(Xanthosoma sagittifolium)was processed into fermented flour using three different

steeping times (12, 24 and 36 h) and three oven-drying temperatures (50, 60, 70oC) in 3 by 3 factorial design. Sun-dried samples were used as control. Fermented cocoyam flour samples

were analysed for functional properties: Water Absorption Capacity (WAC), Bulk Density (BD), dispersibility, Water Solubility Index (WSI) and pasting properties. All analyses were

done in triplicate and effect of steeping time and drying temperature were studied. The flour was cooked into pasteand was subjected to sensory evaluation using a 9-point Hedonic

scale. Steeping times and drying temperatures generally had significant effects (P<0.05) on

WAC, BD, dispersibility, WSI and paste viscosities. However, steeping times and drying temperatures did not have significant effect (p>0.05) on peak time and pasting temperature.

The result of WAC, BD, dispersibility, WSI ranges were 1.11g/g – 1.73g/g, 0.72g/ml – 0.9g/ ml, 25.50% - 34.50%, 5.92% - 10.36% respectively. Flour produced by steeping for 36 h,

oven dried at 50oC had the highest peak (270.21RVU), trough (205.75RVU), breakdown (68.59RVU), final (317.17RVU) and setback (111.42RVU) viscosities. Cooked paste from

fermented cocoyam flour processed by steeping for 36 hours were highly rated by sensory

assessors and there was no significant difference(p>0.05) in their colour, texture and aroma.Steeping for 36 hours and oven-drying at 50oC could be the adopted process for

production of fermented flour from cocoyam (Xanthosoma sagittifolium) for an acceptable cooked paste.









(ISTRC-AB)

91

Performance evaluation of a chipping machine for cassava and yam chips

1Asiru, W. B*; 2Adesina B. S; 1Ebun, K. K. and 1Onatoyinbo O.

Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria1

Agricultural and Evironmental Engineering Dept. Lagos State Polytechnic, Ikorodu, Nigeria2

* [email protected]

Abstract

Root and Tuber crops (RTC) such as cassava and yam are increasingly becoming important in the food systems of the developing countries. The volume of production and large amount

of contribution to calories and nutrition per unit area that come from cassava and yam make

them a viable panacea to poverty alleviation and food security in developing countries. However, post harvest losses in both tuber crops is very high because it is perishable if not

process. One of the methods of preserving cassava and yam is to convert to dry chips. This involved the use of chipping machine and dryer. A prototype chipping machine was designed

and fabricated. The machine was evaluated using cassava and yam tubers. The machine eficiency is 86.5% and 83.0% for yam and cassava chips respectively while the effective

capacity is 797.4kg/hr for yam and 760.5kg/hr for cassava chippings. The average thicness

of the chips produced was 10.05mm and 10.30mm for yam and cassava respectively. There was no significant difference in the chips thickness (p<0.05). The specific energy consumption

of the machine was 0.002Kwhr/kg for both yam and cassava with percentage waste of 2.8% and 4.4% for yam and cassava respectively.

Key words: Yam chip, Cassava chip, Chipping machine and specific energy consumption,



(ISTRC-AB)

92

Nutritive value of four cassava varieties and their effects in broilers rations

1Tewe O. O., O.A. 1Abu, 2P. Kulakow and 3M. A. Mosobalaje

1Department of animal Science, University of Ibadan, Ibadan, Nigeria. 2Cassava Programme, International Institute of Tropical Agriculture, Ibadan, Nigeria.

3Oyo State College of Agriculture, Igboora. Oyo State, Nigeria.

Abstract

Dustiness and micro toxins limit the use of cassava particularly in poultry rations. Cassava grit is a gelatinized product similar to pellets. Four varieties of cassava comprises TMS 01/

1371 (High carotene), TMS 08/8693 (high protein) and TME 419 and TMS 30572 (conventional varieties).

Whole cassava tubers of the four varieties were washed, detailed, grated, dewatered, fried

and labeled as cassava grit. Proximate analysis of the four cassava grit samples was carried out and True Metabolisable Energy (TME) was determined using force feeding techniques

on 10 weeks old broilers. Cassava grit samples except TMS 08/8693 were used to replace 50% maize in the diet of broilers. Proximate values of the four cassava samples varied

significantly. Crude protein and True protein of TMS 08/8693 were 3.05% and 1.42% and significantly higher than the other samples. Fibre content of TMS 30572 (3.42%) was the

lowest and significant (p<0.05) as compared to others. True Metabolisable energy of the

four cassava samples were similar (P> 0.05). Performance was not significantly affected by the dietary treatments. However, cost/weight gain was lower for diets containing cassava

grit (¦ 163.97, ¦ 162.25 and ¦ 163.67 for TME 419, TMS 01/1371 and TMS 30572 respectively) compared to control diet ¦ 181.28. Serum thiocyanate of broilers fed cassava based diets was

higher than value recorded for those broilers fed control diet (1.98mg/dl). High protein content of TMS 08/8693 validated the claim as a high protein variety. Partial (50%) replacement of

maize with cassava grit did not affect performance and economy of production of broilers.

Key words: Broiler, Cassava grit, Serum thiocyanate, True metabolizable energy and True

protein.


(ISTRC-AB)

93

The Effect of Chemical Preservatives on the Quality of Mushroom (Pleurotus

Ostreatus) From Cassava Peels

*+Olotu I,O., *Obadina, A.O., *Adegunwa, M.O., *Sobukola, O.P., *Adebowale,

A.A., **Asagbra, Y., **Akinyemi Akinrinola, O. A., **Asiru, W., *Sanni, L.O. and

***Tomlin Keith *Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta. Nigeria

**Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria

***Natural Research Institute, University of Greenwich, Kent, Chatham, United Kingdom

[email protected]

Abstract

The effect of chemical preservatives on the quality of mushroom (Pleurotus ostreatus)

from cassava peels was evaluated. 500g of Pleurotus ostreatus grown on cassava peels was soaked in five different food grade chemical preservatives, each at two concentrations:

2% citric acid, 4% citric acid, 0.05% sodium benzoate, 0.1% sodium benzoate, 0.05% potassium sorbate, 0.1% potassium sorbate, 0.05% sorbic acid, 0.1% sorbic acid, 0.2% calcium

propionate, 0.3% calcium propionate, 0.05% sodium benzoate + 0.05% potassium sorbate and 0.1% sodium benzoate + 0.1% potassium sorbate for 10 minutes. Mushroom treated

with sterile water was used as control. The treated samples were place on an absorbent pad

and were analysed for their microbial population, colour and texture. Significant reductions (P<0.05) in total aerobic, coliform and Pseudomonas spp counts was observed in all treated

samples when compared with the control. All treatment insignif icantly reduced Staphylococcus spp count (P<0.05). Samples treated with 0.1% potassium sorbate and 4%

citric acid had the lowest total aerobic count (2.00 log cfu/g). All treatments increased the lightness of the mushroom and this value ranged from (90.16-97.87). The redness and

yellowness of chemically preserved mushroom were insignificantly different from the control.

0.05% sodium benzoate and 0.05% potassium sorbate increased the firmness of mushroom by 2.01N and 2.12N respectively. In conclusion, all the chemical preservatives used in this

study minimized changes in the firmness of mushroom, retained the mushroom colour and effectively reduced microbial populations.

Keywords: Mushroom, Total aerobic count, Potassium sorbate, Colour and Texture.



(ISTRC-AB)

94

Bibliographical synthesis to evaluate nutritive needs for meals for food products

and yam bean consumed at the torque mother - child in Benin

J.G. Djidonou1, Y.P. Adegbola11, K. Hell2, G.A. Mensah3

1 Programme d’Analyse de la Politique Agricole (PAPA), Institut National des Recherches

Agricoles du Bénin (INRAB), 01 BP 128 Porto-Novo 2 International Institute of Tropical Agriculture, 08 BP 0932, Cotonou, Benin.

3 Centre de Recherches Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin

Abstract

This article presents literature review regarding the assessment needs for protein and iron of local products and yam bean among torque mother- child within the rural households in the area of introduction of yam bean. The data used for this purpose came from further

investigation to the diagnostic studies performed in the framework of the yam bean project.

These data were collected in 36 households in two agro-ecological zones. The results of literature review showed on one hand that 50% of the torque mothers-children were deficient

in iron and protein, on the other hand the daily average flows of yam bean allowed to cover average needs of daily protein and iron intakes in the subjects. It released a daily average

additional equal to 18,77g ± 23,40g of protein and 12,01mg ± 0.4 iron mg in children of less than 5 years old, and 22,48g ± 30,40g of protein and 6,77mg ± 7,6 mg of iron in the mothers.

In the absence approach of fortification derivatives of cassava which has demonstrated their

limitations, one of the alternative solutions to the difficulties of accessing protein sources and ferric is the introduction of yam bean in the power of households, likely to be a substitute for

the cassava but provides additional nutritional value (iron, protein) as a parameter of differentiation. From where the feasibility introduction of yam bean into the agrarian system

which beyond its function of regeneration of the grounds will contribute to course sure with the improvement the nutritional state of the mothers and the children of less than five years.

Key words: Eradication, nutritional deficiency, yam bean, Benin


(ISTRC-AB)

Towards the development of sweetpotato-based couscous as human food in Benin

Charlotte Fifamè KPOMASSE, Sègla Wilfrid Padonou2, Jean Louis Ahounou

Programme Technologie Agricole et Alimentaire, Centre de Recherches Agricoles

d’Agonkanmey, Institut National des Recherches Agricoles du Bénin, 01 BP 128

Porto-Novo, Bénin.

Abstract

Sweetpotato (Ipomea batatas) is a root crop cultivated and consumed in Benin, and thus contributes to food security particularly during lean days, although the crop is barely considered in agricultural development policies in Benin. Sweetpotato processing and consumption patterns

are very limited in Benin; that may be the basis of the little interest in this crop. The present

study aims to suggest a new utilization of sweetpotato through its processing into a couscous for both urban and rural consumers. Then, roots from a local white flesh variety were processed

to obtain flour which was used to produce a couscous. This couscous was steam-cooked following the same procedure as the wheat-based cooked couscous CAMEL purchased in a

local market. The foods obtained were submitted to the panellists’ appreciation for comparison. Although significant differences were observed between wheat-based couscous and

sweetpotato-based couscous regarding the colour and the flavour, the mean score obtained

by the later couscous showed that the product had acceptable to good sensory quality. Since Benin is one of the West African countries targeted by the Sweetpotato for Profit and Health

Initiative (SPHI) which goal is to “enhance the lives of 10 millions households in 16 Sub- Saharan Africa countries by 2020 through the effective and diversified use of sweetpotato”,

this study opens an interesting perspective for sweet potato utilisation, particularly the orange flesh sweetpotato which is in introduction in Benin.

Keywords: sweetpotato, couscous, sensory quality

95


(ISTRC-AB)

96

Application of Near Infra-Red Reflectance Spectroscopy (NIRS) for screening of fresh cassava (Manihot esculenta) genotypes for high concentrations of

Provitamin A carotenoids

Oladeji Emmanuel Alamu1, Bussie Maziya-Dixon*1, Thomas zum Felde 2, Peter

Kulakow1 and Elizabeth Parkes1

1International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria 2 International Potato Centre (CIP), Lima, Peru

* [email protected]

Abstract

There are several initiatives (such as HarvestPlus and SASHA) that have been set up to increase the pro-vitamin A concentration and other micronutrients like iron and zinc in staple

food crops to help improve human nutrition status in developing countries. Biofortified cassava with enhanced provitamin A carotenoids levels is supposed to have a significant positive

impact on nutrition status and overall health, especially for poorer communities where cassava is mainly consumed. Realizing the potential of root and tuber crops in contributing to improved

nutrition status of low income populations requires the need to ensure fast and cost effective techniques in the determination of micronutrient levels for crop improvement. The purpose

of this study was to evaluate existing NIRS calibrations to analyse provitamin A carotenoids

content of selected fresh yellow root cassava genotypes to orient nutritional enhancement of cassava in West Africa. A total of 50 freshly harvested cassava genotypes were obtained in

four replications. The HarvestPlus Standard method of sampling was employed and the samples were scanned twice by NIRS within the range of 400 to 2498 nm. Existing NIRS

calibration equations were used to predict the â-cryptoxanthin, 13-cis â-carotene, trans â- carotene, 9-cis â-carotene, total â-carotene and the total carotenoid concentrations of the

samples. The predicted values found for total carotenoids (TC-spec reference) ranged from

3.93 to 10.51µg/g with mean of 7.07±2.55 µg/g for ICT, 7.97 to 11.03µg/g FW with mean of 9.40±0.76 µg/g for yellow root trial 8 and 6.38 to 10.44µg/g with mean of 8.74±1.07µg/g for

yellow root trial 9. The corresponding tota l carotenoid results using reference spectrophotometric method (TC-spec) were found to range from 2.57 to 9.97µg/g with mean

of 5.66±2.99µg/g for ICT,: 6.55 to 8.74µg/g with mean of 7.74±0.64 µg/g for yellow root trial 8 and 4.22 to 11.00µg/g with mean of 7.57±1.54µg/g for yellow root 9. There is significant

(d” 0.001) positive correlation (r= 0.55) between TC-predicted by NIRS and TC-spec. There

is also significant (d” 0.001) positive correlation (r= 0.52) between trans â-carotene predicted by NIRS using HPLC reference and TC-spec This study shows that the developed NIRS

calibration equations can be used to predict total carotenoids and trans â-carotene content of yellow root cassava and can serve as a fast and cost-effective method for screening of large

sample sizes by the cassava breeding programs.



(ISTRC-AB)

97

Preliminary investigation of the effect of granulation on the quality characteristics

of instant pounded yam flour

*Asiru, W.B1., Kosoko, S.B2., Owolabi, S.O2., Adegbite, A1 and Elemo, G.N1,2.

1Project Development and Design Department,

Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria 2Food Technology Department,

Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria

bolaasiru@yahoo .co.uk

Abstract

The study is a preliminary investigation of the effect of granulation prior to drying on the quality characteristics of instant pounded yam flour. The instant pounded yam was produced

using the steam parboiling method while a modified method was used to produce the granulated sample which involves granulation immediately after parboiling before drying. The results of

the proximate composition revealed that the granulated sample has a better proximate composition value with the moisture content of 7.52% as against 8.79% for non-granulated

sample. Also, there was a slight increase in the protein content of the granulated samples. In

terms of sensory rating the granulated sample has a better sensory rating for colour, texture, taste and overall acceptability.

Key words: Instant Pounded Yam flour, Granulation, Steam parboiling, proximate

composition.



(ISTRC-AB)

98

Contribution of infant flour enriched with OFSP to improving the nutritional and

immune status of young children moderately malnourished in the medical district

of Saint-Camille , Ouagadougou.

Toe Oumar1, Mouhoussine Nacro2, Jacques Simpore 3, Hema Adama2, Gnoula

Charlemagne 3, Blaise Sondo1,4, Somda Jean Celestin1, Tanoh/BrouAdjo Marie 1

and Laeticia Ouedraogo4

1Hellen Keller International, Ouagadougou, Burkina Faso 2 University of Ouagadougou, Burkina Faso

3 Bio-Molecular Research Centre (CERBA-Ouagadougou), Burkina Faso 4 Health Science Research Institute (IRSS), Ouagadougou, Burkina Faso

[email protected]

Abstract

The study was undertaken as a contribution to the fight against micronutrient deficiencies such as vitamin A, which is a priority issue for children under 5 years in Burkina Faso. It

integrates research on antioxidants involved in the prevention of degenerative diseases such as diabetes, certain cancers and cardiovascular diseases. An assessment of the effect of the

consumption of orange-fleshed sweetpotato (OFSP) on the nutritional and health status of moderately malnourished children monitored at the Center of Nutritional Recovery (CREN)

of St. Camille through a quote before and after intervention with a control group. Two groups

of children (50 children per group) in a situation of moderate malnutrition were recruited and subjected to the use of two types of porridge for a period of one month. The first group

received MISOLA porridge enriched with OFSP. The second, that is, the control group received the pure MISOLA in strict accordance with the national protocol for the management

of malnutrition. At the beginning and end of the study, anthropometric measurements (age, weight, height, arm circumference, etc.) were recorded on the children. In addition, blood

samples were taken for blood tests on resistance to disease (CD4, NFS) and for the assessment

in the blood content in micronutrients (vitamin A and antioxidants) originally contained in the OFSP recipes. The results of these measurements are in progress and will be compared in

order to draw conclusions about the contribution of OFSP in the improving of the nutritional status of malnourished children.



(ISTRC-AB)

99

A comparative study of frying, organoleptic and textural characteristics of white yam (Dioscorea rotundata) and water yam (Dioscorea alata) chips for food uses

Oluwole, O.B, Asiru, W.B, Jegede A, Alagbe, G and Elemo, G.N

Federal Institute of Industrial Research, Oshodi, Lagos, Nigeria

Abstract

White yam (Dioscorea rotundata) and water yam (Dioscorea alata) were manually peeled, washed and chipped (width 10mm, thickness 10mm). The raw chips were subjected to heat

treatment (900C for 15mins) followed by treating with 0.3% food grade citric acid and 0.3%

food grade sodium metabisulphite. The treated chips were subsequently drained of water manually.

The chips were deep-fried at 1700C for 0 to 18 minutes. The profile of loss of water during frying of the different chips were noted, the textural parameters and organoleptic characteristics

were also determined using semi trained panelists in the institute. The study revealed that the loss of water during frying for white yam varied between 73.87% and 32.75% between

frying time of 0 and 18 minutes while it varied between 80.19% and 31.03% for water yam

within the same frying period. The textural properties of the resulting fried chips from white yam indicated that as the time of frying increased, there was significant reduction (pd”0.05)

in peak force while there was an increasing trend with frying time in terms of deformation at peak and force at break for the chips while the energy to peak and energy to break were not

significantly affected (pe”0.05). Organoleptic evaluation revealed that the deep-fried chips with minimum frying time of 10 minutes were acceptable irrespective of the variety of yam.

Key words: White yam, chips, deep fry, water loss, texture, organoleptic , water yam.


(ISTRC-AB)

10

0

Determining the effects of storage duration on the cooking qualities of cocoyam (Colocasia esculenta)

1Ezeaku, P.I., 2UgwokeK.I. and 2Eze, S.C.

1Department of Soil Science, University of Nigeria, Nsukka 2Department of Crop Science, University of Nigeria, Nsukka

Abstract

Information on the cooking qualities of cocoyam (Colocasia esculenta) cormels when stored in different conditions for a long time is paucive, hence this study. Cocoyam corms were

stored in at ambient conditions and moist saw dust for sixteen weeks. Corm samples were

taken from each storage method, cooked and qualities assessed by a panel of 15 experienced cocoyam farmers, every two weeks for the storage periods. Result showed that storage

duration and methods significantly (p<0.05) affected the cooking qualities of stored cocoyam when compared with unstored samples. The cooking qualities such as stickiness, texture,

color and appearance of cocoyam remained insignificant within 0 to 4th week but fluctuated thereafter. Moist saw dust (Msd) increased and maintained the cooking qualities than storage

in ambient conditions when stored for a long time. The use of Msd required regular moistening

to maintain the moisture range.

Keywords: Cocoyam cormels, different conditions, storage, cooking qualities, Nigeria


(ISTRC-AB)

101

Some alternative energy sources [cassava (manihot esculenta), sweet potato

(ipomea batatas), and cocoyam (xanthosoma sagittifolium schott.)] for poultry and

piggery production and it’s implications for food security

Chidimma L. Obi1, *Chika E. Oyeagu2 ,Augustine O. Ani2, Petrus E. Nwakpu1,

Scholastica N. Okongwu1, Patience N. Onu1, Ugochukwu S. Ekwu2, Murphy B. Enwezor1

1Department of Animal Science, Ebonyi State University, Abakaliki, Nigeria. 2Department of Animal Science, University of Nigeria, Nsukka, Nigeria.

*[email protected]

Abstract

This paper discusses cassava, sweetpotato and cocoyam as alternative sources of energy for poultry and pig productions. Cassava, sweetpotato, cocoyam and their by-products has

been successful in the diets of Poultry and Pigs. Different processing methods (silage, drying,

heat treatment, etc) of these alternative sources of energy (cassava, sweetpotato and cocoyam) have increased their potency in the diets of non-ruminant animals (Poultry and Pigs). The

potential constrains and nutritional attributes of these alternative energy sources should be considered before incorporating them in the diets of poultry and pigs. With adequate processing

and inclusion rates in the diet of these alternative energy sources (cassava, sweetpotato and cocoyam), increase in poultry and pig production will be ensured in the humid tropics and this

will result in maximum returns to poultry farmers and availability of chicken, eggs and pork

meat to the consumers at affordable prices.

Keywords: Alternative sources, poultry, energy, pigs, processing methods, humid tropics.



(ISTRC-AB)

10

2

Assessment of the organoleptic qualities of composite cassava–cowpea “Gbodor”

M. S. E. Williams and N.M Anthony

Sierra Leone Agricultural Research Institute; Njala Agricultural Research Centre (NARC);

PMB 540 Freetown

[email protected],

Abstract

The use of cassava in pastry products with low protein content is of great concernin Sierra Leone. As a way of increasing the protein content of “gbodor” (a Sierra Leonean snack

prepared from grated cassava, fried in palm/vegetable oil) and to enhance the nutritional status of rural communities, cowpea paste (legume rich in protein) was added to the grated

cassava to formulate a composite paste. This study evaluated the sensory characteristics of

gbodor fried from cassava-cowpea composite paste. Cassava-cowpea composite paste with varying cowpea levels ranging from 20-50% were used in the gbodor recipe. Sensory panelists

evaluated the differences in taste, colour, texture, flavor and general acceptability of the “gbodor” using a 9 – point hedonic scale. Colour, taste and flavour were significantly affected

by addition of cowpea paste. “Gbodor” colour progressively darkened as the cowpea paste level increased. Increasing cowpea paste levels resulted in softness of the “gbodor” from

15T to 32T with substitution of 50% of cassava paste with 50% of cowpea paste but flavour

scores did not differ significantly among the “gbodor” samples.”Gbodor” from a composite blend between 35-50% cowpea were most preferred in terms of texture and flavour. The

addition of cowpea paste to cassava paste positively affected the sensory characteristics of the “gbodor”. This has the potential of producing gbodor with desirable sensory characteristics

from cassava-cowpea composite paste.

Key words: Assessment, Organoleptic, Cassava – Cowpea, “Gbodor”



(ISTRC-AB)

103

Effect of variety and processing methods on the functional and pasting properties

of high quality yam flour (HQYF)

1Wahab, B.A., 1*Sobukola, O.P., 1Adebowale, A.A., 1Obadina, O.A., 1Kajihausa, O.

E., 2Adegunwa, M.O., 1Sanni, L.O., 3Tomlins, K. 1Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria. 2Department of Food service and Tourism, Federal University of Agriculture, Abeokuta, Nigeria.

3Natural Resources Institute, University of Greenwich, United Kingdom * [email protected]

Abstract

The functional and pasting properties of high quality yam flour (HQYF) (unfermented yam flour) obtained from four varieties of yam tuber (Dioscorea sp.) processed using different

pretreatment methods (potassium metabisulphite at 0.28% for 15 min and blanching at 70 ºC for 15 min) and drying methods (cabinet at 60 ºC for 24 hr and sun drying for 2 days) using

a 4×2×2 factorial design were studied to contribute to knowledge base for product diversification and new product development. Data obtained were analyzed by subjecting

them to general linear model (multivariate tests) and the means with significant differences were separated at 5% level. Functional properties of HQYF samples were found to be in the

range of 62.83-69.17% (Dispersibility), 0.70-0.91 g/cm3 (bulk density), 1.90-2.86 (water

absorption index), 5.05-31.11% (foaming capacity), 58.67 – 211secs (Wettability), 55.83- 66.70% (emulsification capacity) and 2 – 5 %w/v (Least Gelation). Variety significantly

(p<0.05) affect the functional properties of HQYF samples. The interactive effect of variety, pretreatment and drying method on the functional properties were significant (p<0.05) except

on emulsification capacity and least gelation. For the pasting properties; the peak, trough, breakdown, final and setback viscosities ranged between 181.83 and 506.81, 94.44 and 404.86,

39.50 and 357.33, 157.11 and 649.58, 56.72 and 321.44RVU, respectively. The peak time and the pasting temperature were also observed to vary between 4.6 and 5.8 min and 69.9

and 88.4 ºC. Variety significantly (p<0.05) affect pasting properties of HQYF while drying

methods was not significant (p<0.05) for all except peak viscosity. Pastes of HQYF from D. dumentorum were relatively stable when cooked hence will have a lower tendency to undergo

retrogradation during freeze/thaw cycles than HQYF from other varieties. However, the combine effect of variety, pretreatment and drying method on pasting properties were not

significant (p>0.05) except for peak and final viscosities. The significant variation observed among HQYF samples could contribute significantly to selection and improvement of the

yam varieties for specific food applications to stimulate their production and utilization.

Keywords: Yam, Dioscorea sp., functional properties, pasting properties.



(ISTRC-AB)

Keeping quality of unfermented wet cassava cake

Buliyaminu A. Alimi1, Adejoke F. Bello2, Ololade Abraham2, Taofik A. Shittu2,

Lateef O. Sanni2, 1Department of Food, Agricultural and Bio-Engineering, Kwara State University, Malete.

PMB 1530, Ilorin 2Department of Food Science and Technology, Federal University of Agriculture,

PMB 2240, Abeokuta

[email protected]

Abstract

Processing of wet cassava cake (WCC) used to high quality cassava flour (HQCF) may be delayed due to factory or transportation logistics. Up to date technical data on the spoilage of

WCC is yet to be published. Hence, this paper documents the physicochemical and microbial

changes in ambient stored WCC. The flour’s functional properties and sensory qualities of their thick paste as affected by the 5-day storage were also studied. The pH and moisture

content of WCC reduced from 4.52 to 3.54 and 49.34 to 40.21%, respectively, while total titratable acidity increased from 0.049 to 0.099%. The total plate and lactic acid bacteria

(LAB) counts increased exponentially during storage. The LAB (Lactobacillus sp., Bacillus sp., and Candida sp.) were isolated within 2-day storage while fermentative fungi

(Aspergiluus niger and Geotricum candida) were isolated from the WCC after 3 days. Bulk density and dispersibility of flour increased over the storage period while the pasting

viscosities reduced within 3 d of storage and subsequently increased till the 5th day. Pasting

temperature and peak time did not differ in first 3 days but later increased with time. The sensory qualities of the cooked paste from the stored and freshly prepared WCC did not

differ until after 3 days when the sensory scores of stored samples’ fell below acceptable limit. Conclusively, mold growth was implicated as the major cause of quality loss after the

3rd day of storage. Based on the data generated, strategies to increase the shelf-stability of

WCC were also discussed.

104



(ISTRC-AB)

105

Exploiting Orange-fleshed sweetpotato for better nutrition and income

Mariama Fofanah

International Potato Center (CIP) C/O ILRI P O Box 5689. Addis Ababa, Ethiopia.

[email protected]

Abstract

In Tigray, Ethiopia, poor diet diversity contributes largely to widespread food insecurity and malnutrition particularly in women and children; most families depend solely on cereal based crops for production of food staples and roots and tubers remain underutilized. Since 2012,

the International Potato Center has been promoting the production and consumption of vitamin

A rich orange fleshed sweet potato (OFSP) through an Irish Aid funded pilot project. OFSP is suited to the agro-ecology of Tigray, and despite being a new crop has the potential to

diversify diets and improve the vitamin A status and livelihoods of rural households. Processed OFSP flour can potentially be added to teff or wheat flour to produce traditional Ethiopian

flat bread (enjera), breads, cakes and weaning food blends. The purpose of this poster is to highlight initial findings obtained from field research evaluating the production and consumer

acceptability of OFSP based food products in Tigray Ethiopia.



(ISTRC-AB)

106

Production and appreciation of gari enriched with Yam bean (Pachyrhizus-spp) by

processors in South and Central Benin

Paul. Houssou13, Sègla. Wilfrid Padonou1, Patrice. Y. Adegbola2, Jean Louis

Ahounou1, Denis Olou2, Hermine Y. A. Djivoh1, Pascal Fandohan1, Prof. Guy.

Apollinaire. Mensah3

1Programme Technologie Agricole et Alimentaire, Centre de Recherches Agricoles


Porto-Novo, Bénin 2Programme Analyse de la Politique Agricole, Centre de Recherches Agricoles d’Agonkanmey,

Institut National des Recherches Agricoles du Bénin, 01 BP 128 Porto-Novo, Bénin 3Centre de Recherche Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du


Abstract

The objective of the study was to test with the processors the use of yam bean associated

with cassava to produce enriched gari. Seven women’s groups, producing gari were selected in five different regions in the south and center of Benin. Mixtures of 25% yam bean + 75%

cassava and 50% yam bean + 50% cassava were used. Gari from 100% cassava served as a control. Different gari obtained were analyzed and their organoleptic quality was appreciated

evaluated by the processors. Results obtained show that the production of enriched gari was more difficult for the processors. The processing duration (10 hrs 54 min) used to process

100 kg of cassava into gari was less than that was used to process 100 kg of the mixture (

25% yam bean + 75% cassava and 50% yam bean + 50% cassava) that were 12 hrs 27 min and 14 hrs 13min respectively. The processing yield obtained for gari 100% cassava is

significantly (P < 0.05) higher (23.15%) that those recorded for Gari enriched with 50% of yam bean (14.34%) and for gari enriched with 25% yam bean (20.95%). The organoleptic

evaluation revealed that, with reference to gari 100% cassava, women processors prefer gari enriched with 25% of yam bean than the gari enriched with 50% of yam bean. The

protein content detected for gari enriched 50% of yam bean was higher (1.54% bs) than gari

from 100% cassava and gari enriched with 25% of yam bean of which protein content were quite similar (about.1.12 % bs).

Keywords: Yam bean, cassava, processing yield, preference protein.


(ISTRC-AB)

107

Feeding of grasscutters (Thryonomys swinderianus) of breeding with the diets of

dolic tuberous (Pachyrhisus erosus) in Benin

Pomalegni S. C. B.14, Anato M. M. A.2, Adegbola P. Y1, Guedou M.S.E1,

Mensahs. E. P1, Dahouda M.2, Fandohan P.1 and Mensah G. A.1

1 Laboratoire des Recherches Zootechnique, Vétérinaire et Halieutique (LRZVH), Institut

National des Recherches Agricoles du Bénin (INRAB), 01 BP 884 Recette principale,

Cotonou, Bénin 2Département de Production animale / Faculté des Sciences Agronomiques / Université

d’Abomey-Calavi, BP 526 Cotonou

Abstract

The study aimed to determine the incorporation rates of the roots of dolic tuberous (Pachyrhisus erosus L. Urban) in the diets of grasscutters (Thryonomys swinderianus)

raised during 30 days in Benin. Thus, 18 young grasscutters with an average live weight of 1.175 ± 0.260 kg were used for the test and were divided into 6 groups of 3 heads, each into

a simple Fisher block with 6 treatments and 3 replicates. The 6 groups received the diets containing 0%, 20%, 40%, 60%, 80% and 100% of dolic tuberous roots.The results showed

that the average individual daily feed intakes of the grasscutters were highly significantly different (P=0.000). From one another the highest daily feed intake of 46.43 ± 7.67 g DM

(dry matter) was obtained with grasscutters fed on diet containing 40% of dolic tuberous roots.The average values of Dry Matter Digestibility (DMD), of Daily Weight Gain (DWG)

and of Feed Conversion Ratio (FCR) between the six experimental groups were statistically

the same. Highly significant correlations were obtained between the DWG and the DMD (0.625 for P =0.009) and also between the DWG and the FCR (-0.813 for P=0.000).

Experimental diets containing 60% and 100% of dolic tuberous roots showed the best technical performances. In spite the short duration of the study and the inexistence of significant

difference between the animal performances excepted the daily feed intakes, those diets can be used in substitution of fodder with yam bean roots in grasscutter’s diet.

Key words: Grasscutters, diet, feed intake, high correlation, Benin


(ISTRC-AB)

108

The use of the low dry matter yam bean Pachyrhizus erosus storage roots in

drinks processing in Benin

Sègla Wilfrid Padonou1, Jean Louis Ahounou1, Patrice Y. Adegbola2, Agossou

Hounyèvou Klotoe 1, Adolphe Adjanohoun3, Kouessi Aihou4, Pascal Fandohan1,

Guy Apollinaire Mensah5

1 Programme Technologie Agricole et Alimentaire, Centre de Recherches Agricoles


Porto-Novo, Bénin. 2 Programme Analyse de la Politique Agricole , Centre de Recherches Agricoles d’Agonkanmey,

Institut National des Recherches Agricoles du Bénin, 01 BP 128 Porto-Novo, Bénin. 3 Centre de Recherches Agricoles Sud de Niaouli, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin. 4 Centre de Recherches Agricoles Centrede Savè, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin. 5 Centre de Recherches Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin.

Abstract

Effluent expulsed as waste from fresh yam bean (Pachyrhizus erosus) storage roots during processing was used to prepare soft and hard drinks. The storage roots were harvested at

six months maturity from the experimental fields of the Agricultural Research Centers of

Niaouli and Savè. The processing consisted in peeling, grating and pressing the storage roots to obtain the effluent which was bottled and pasteurized. Sugars in the effluent were identified

and quantified using a High Performance Liquid Chromatograph (HPLC). It appeared that yam bean’s effluent contained 12.32 mg/ml of sucrose, 21.01 mg/ml of glucose and 14.08

mg/ml of fructose. The table juices processed from the effluent had a good sanitary quality till twelve months storage time as shown by microbiological analyses, and were positively

appreciated by panellists. Moreover, analysis showed that the alcoholic drinks obtained

following the distillation of the effluent fermented by the yeast Saccharomyces cerevisiae contained ethanol. The study demonstrated the usefulness of this waste which allowed to

obtain sweet table juice positively appreciated by panellits and a good quality alcoholic liquor.

Keywords: Legume-root crop, soft drinks, hard drinks, HPLC, Benin.


(ISTRC-AB)

109

Chemical Composition and the Effect of Processing on the Phytochemical content of Cocoyam (Xanthosoma maffa (Scoth)) tuber.

Ukom, A.N1*, Ojimelukwe, P.C2, Ezeama, C.F2, Ortiz, D.A3, and Aragon, I.J3

1Dept. of Food Science and Technology, Abia State University, Uturu, Nigeria. 2Dept. of Food Science and Technology, Michael Okpara University of Agriculture,

Umudike, Nigeria. 3Nutrition Quality Laboratory, International Center for Tropical Agriculture, (CIAT), Colombia.

*[email protected]

Abstract

Xanthosoma maffa (Scoth) is an underutilized tropical root crop that is going extinct despite its potential as micronutrient source in addition to providing energy in the diet. The need to investigate the micronutrient content of this staple root crop vis-à-vis the processed forms in

which it is consumed are the major reasons for this study. The chemical composition and the

effect of processing (boiling, roasting, deep-fat frying, and oven-drying) on the phytochemicals (polyphenols, flavonoids, and carotenoids) content of Xanthosoma maffa (Scoth) tuber sample

were undertaken. Results of the chemical composition show the following: moisture 69.49%, crude protein 7.13%, crude fiber 5.53%, crude fat 0 .22%, ash 4.73%, and carbohydrate

12.92%. The result of the mineral content were: Nitrogen 11.40g/kg, Phosphorus 3.71g/kg, Calcium 0 .5g/kg, Magnesium 1.55g/kg, Sulphur 0.84g/kg , Barium 6.97mg/kg, Iron 21mg/kg, Manganese 12.98mg/kg, Copper 5.26mg/kg, Zinc 118.89mg/kg, Sodium 17.17mg/kg, and potassium 17.83mg/kg respectively. The polyphenol contents of fresh and processed Xanthosoma maffa (Scoth) ranged from 399.56 (boiled) to 134.49mgGAE/100GFW (oven- dried). The flavonoids content ranged from 155.38 (fresh) to 48.58mgCE/100gFW (boiled). Also, the carotenoids content of the fresh and processed sample ranged from: lutein 1.67 (fresh) to 0.22µg/g (fried), á-carotene 3.36 (fresh) to 0 .09µg/g (fried), all trans-â-carotene

3.88µg/g (fresh) to 0.01µg/g (fried), 9-cis-â-carotene 1.13 (fresh) to 0.24µg/g (fried), 13-cis- â-carotene 0.98 (boiled) to 0.06µg/g (oven-dried), total carotenoids 14.87 (fresh) to 2.82µg/g (fried), phyteone 15.84 (fresh) to 3.27µg/g (fried), and phytofluene 15.74 (fresh) to 3.26µg/ g (fried). The overall result indicates that Xanthosoma maffa (Scoth) is high in protein, fiber, iron, and zinc. Processing methods increased the content of polyphenols with the exception of oven-dried method, while the flavonoids content decreased in all the processing methods. Also the processing methods decreased the content of the carotenoid species with the exception of 13-cis-â-carotene which increased in the boiled and fried methods. Carotenoids of roasted method was the most stable with only 32.3% loss in the total carotenoids content, while fried method caused severe loss in the carotenoids content amounting to 81% of the total carotenoids. Despite the processing losses in the flavonoids and carotenoids of this staple, this result suggests that Xanthosoma maffa (Scoth) is high in some micronutrients and could provide a sustainable amount of these nutrients to ameliorate hidden hunger and boost human health.

Key words: Xanthosoma maffa (Scoth), Chemical composition, Micronutrients,

Phytotochemicals Processing methods.



(ISTRC-AB)

110

A multivariate analysis of the relationship between quality of sweetpotato flour

(‘elubo’) and sensory properties of paste (‘amala’)

*Fetuga, G. O.1, Tomlins, K. I.2, Henshaw, F. O.1 and Idowu, M. A.1

1Department of Food Science & Technology, Federal University of Agriculture, Abeokuta,

Nigeria. 2Natural Resources Institute, University of Greenwich, Kent, United Kingdom

*[email protected]; [email protected]

Abstract

The concept of food quality is based on conformity with consumer requirements and acceptance, and is determined by their sensory attributes and chemical composition among other properties. Multivariate statistical methods have played a major role where assessments

of quality are made against the background of several qualities of the food. The multivariate

methods that have been used in the assessment of food quality include principal component analysis, factor and cluster analysis, canonical analysis, discriminant and stepwise discriminant

analysis as well as multiple regression analysis. Some of these methods were employed in this study to evaluate important parameters for characterization and quality control analysis

of sweet potato flour (‘elubo’) and paste (‘amala’).The first two principal components accounted for 45.13% and 26.87% respectively. The dominant variables in the first component

were the hunter colour parameter b* (yellowness), water solubility and total sugar of ‘elubo’

and they were negatively correlated with sticky texture and acceptability of ‘amala’.The dominant variables in the second component were moisture content and paste viscosities of

(‘elubo’) and they were correlated with thick texture and sour taste of ‘amala’. Two linear regression models were generated which related the properties of sweet potato ‘elubo’ to

acceptability of (‘amala’) and they were found to be suitable for estimating consumer acceptability (R2 = 0.998 and 0.716). The more significant model had b* and total sugar as

most reliable predictors of acceptability.





(ISTRC-AB)

111

eqv

Effect of agroecology variability on dry matter, cyanogenic potential (cnp) and

chemical composition of 30 cassava clones.

O.O. Etukudo,1,2 L.A. Babatola2 and B. Maziya – Dixon1

1International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria 2Department of Agronomy, University of Ibadan, Ibadan, Nigeria.

[email protected] [email protected] .uk

Abstract

In an ecological stressed or economically stressed communities, as is the case in Nigeria, cassava (Manihot esculenta Crantz) quality and safety is an issue in order to meet end-user

requirements and expectations. Consequently, this study was designed to evaluate the dry

matter, chemical composition and cyanogenic potential level of the newly improved cassava genotypes (clones). 30 clones of the cassava storage roots, replicated four times on the field

in three agroecological zones of Nigeria ( Ibadan, Mokwa, and Zaria), were evaluated for 2008 and 2009 season. At harvest, 12 months after planting (MAP), the cassava storage

roots were sampled according to Harvestplus(2004) procedure. The dry matter, CNP, free sugar and starch, amylose content were determined using standard analytical procedures.

Means square (MS) from the combined analysis of variance (ANOVA) were significant for

most of the sources of variation for most parameters evaluated. Across the agroecologies, best performance for starch was observed in Zaria with clone 01/0034 having 54.52%.

Mokwa recorded the highest mean value (21.71%) for amylose content. Dry matter contents ranged between 28.21% (01/1663) – 38.90% (99/0554). Highest CNP levels 10.81 mg HCN

per 100g was observed in Zaria where the lowest dry matter content (28.21%) was recorded for clone 01/1663.




(ISTRC-AB)

112

Descriptive sensory analysis and consumer acceptability of a cooked paste

(‘amala’) from sweetpotato

*Fetuga, G. O.1, Tomlins, K. I.2, Henshaw, F. O.1 and Idowu, M. A.1

1Department of Food Science & Technology, Federal University of Agriculture,

Abeokuta, Nigeria. 2Natural Resources Institute, University of Greenwich, Kent, United Kingdom

*[email protected]; [email protected]

Abstract

‘Amala’ is a generic term in Nigeria, used to describe a thick paste prepared by stirring flours (‘elubo’) from yam, cassava or unripe plantain, in hot water, to form a smooth and

thick consistency. Nigeria is the third largest producer in the world with a production of 2.12

million metric tonnes. In spite of the nutritional advantages of the sweetpotato, the crop is still underutilized. To overcome the limitations of its high perishability and low utilization in terms

of adaptation to local dietary preferences, the effect of two processing methods (parboiling and soaking) were evaluated on the quality of ‘elubo’from two yellow-fleshed and one orange

fleshed sweet potato (SP) varieties. The ‘elubo’ was cooked into paste ‘amala’ and subjected to Quantitative Descriptive Analysis (QDA) by six trained panelists. The samples were also

subjected to consumer acceptability test on a ‘9-point hedonic scale’ using 100 consumers.

Twelve descriptors were identified for sensory attributes of appearance, colour, taste, texture and odour of sweetpotato ‘amala’. The ‘amala’ samples differed significantly (p<0.001) in

all the attributes except in greasy appearance and sour taste. The data could be useful for further optimization of the SP ‘amala’ and contribute directly or indirectly to other activities

such as quality evaluation and quality maintenance during commercial production of SP ‘elubo’.





(ISTRC-AB)

113

Development and sensory evaluation of akara from sweetpotato flours (a local,

cheap, Sierra Leonean snacks)

N.M Anthony, M. S. E. Williams

Sierra Leone Agricultural Research Institute, Njala Agricultural Research Centre (NARC); PMB

540 Freetown; Fax 232 224 439

[email protected]

Abstract

Flour from orange fresh sweet potato variety were developed in to “Akara” a common Sierra Leonean snack to address post harvest lost, vitamin A and replace rice flour which are

very expensive in making “akara”. This study evaluated the sensory characteristics of “akara”

developed from sweetpotato flour. The flour was obtained by peeling, washing, chipping, sun drying and milling of the Sweetpotato roots. The “akara” was served to thirty trained panelists

to evaluate the taste, flavour, colour, texture, appearance and general acceptability using a nine point hedonic scale. Result indicated likeness of the “akara” with respect to taste, colour,

flavour, texture, appearance and general acceptability. Mean scores ranges of attributes evaluated were: taste (2.20 to 3.45), colour (2.50 to 4.10), flavour (2.10 to 4.30), texture

(2.05 to 4.05), appearance (2.15 to4.24) and general acceptability (3.00 to 4.45). Results

indicated that taste, flavour, colour and texture of “akara” developed were significant. Sweetpotato/rice flour composite “akara” indicated no significant (p>0.05) difference in terms

of taste with that of the 100% sweetpotato. The results of the sensory attributes of the “akara” developed from various sources indicated that rice/sweetpotato composite flour can

be used to prepare sweetpotato-based snack with no significant variance in consumer acceptability. This recipe is recommended for promotion as a mean of addressing the vitamin

A issue which is a serious problem in Sierra Leone.

Key words: Development, Evaluation, Sweetpotato, “Akara”, Sensory,



(ISTRC-AB)

114

Effect of processing parameters on some quality attributes of yam starch and

gluten based expanded fried snack

1,*Akegbejo-Samsons, T., 1Sobukola, O.P., 1Henshaw, F.O., 2Afolabi, W.A.O. and

1Sanni, L.O. 1Department of Food Science and Technology, Federal University of Agriculture,

P.M.B. 2240, Abeokuta, Nigeria. 2Department of Nutrition and Dietetics, Federal University of Agriculture,

P.M.B. 2240, Abeokuta, Nigeria.

* [email protected]

Abstract

This study was conducted to investigate the effect and optimization of processing parameters including frying temperature (160 and 1700C), frying time (4 and 6 min), gluten level (20 and 25%, d.b.) and moisture level (38 and 44%) on some quality attributes (oil content, expansion, texture, moisture content and colour parameters) of Yam (Dioscorea rotundata) starch and gluten based expanded snack during deep fat frying. Starch from yam tubers was extracted using standard procedures and then analyzed for proximate composition. Sixteen experimental runs of 3 batches each based on a 24 factorial design were used to study effect of the independent variables as well as to optimize the processing parameters. Formulated dough was sheeted into a thickness of 2±0.02 mm and controlled by constant weight of about 2g after cutting into discs of 4 mm and then fried. The sensory attributes of the fried snack (produced at optimized condition) were obtained through Quantitative Descriptive Analysis using a trained panel of 15 judges and acceptability levels obtained through Hedonic scaling using 35 sensory panelists. Data was analyzed using Design Expert Version 6.0 and means with significant difference at 5% level were separated. The proximate composition of the extracted starch includes; protein, 0.3%; ash, 0.4%; moisture content, 8.22%; fat, 0.73%; crude fibre, 2.0%; and the total carbohydrate content, 88.35%. Mean values for oil content, expansion, texture and moisture content ranged from 1.56 to 24.31%, 15.25 to 23.45mm, 16.40 to 36.20N and 6.73 to 9.83%, respectively. Values obtained for colour parameters L*(lightness), a*(redness), b*(yellowness) and colour change (ÄE*) ranged from 71.91 to 84.46, -2.35 to 4.12, 19.59 to 35.43 and 21.05 to 35.28, respectively. Model developed for expansion (R2=0.88) revealed a significant effect (p<0.05) of frying temperature and gluten level while those developed for texture (R2=0.85) and moisture content (R2= 0.70) revealed a significant effect (p<0.05) of frying time. The developed models for lightness, yellowness and colour change shows a significant (p<0.05) effect of frying temperature and frying time. The optimized frying conditions was found to be frying temperature of 160oC, frying time of 4 mins, moisture level of 44% and gluten level of 25%. The sensory panelists indicated a high degree of likeness for the fried yam starch and gluten based expanded snack. In conclusion, this study has shown how food ingredients (yam starch; 75%, gluten; 25% and water; 44%) can be combined in a matrix to obtain fried products with oil content of 9.28%, acceptable texture of 19.79N, maximum expansion of 21.75 mm and golden yellow surface colour (ÄE* of 26.85).

Key words: Yam starch, gluten, frying, quality, processing



(ISTRC-AB)

115

Physicochemical Properties and Baking Qualities of Baked Wheat Products

Supplemented with Pigeon Pea and Cassava Flours

By: S. Chilungo1, P. Ng2, M.Bennink2 and L.Bourquin2

Email: [email protected] , [email protected], [email protected], [email protected] 1 Chitedze Agrcicultural Research Station, P.O.Box 158, Lilongwe, Malawi

2 Michigan State University, USA

Abstract Supplementation of wheat products with cassava and pigeon pea flours is a sustainable way to produce economical and nutritious baked products. The aims of this study were to evaluate

the effects of cassava and pigeon pea flour supplementation on the physicochemical properties (chemical composition, viscosity, dough rheology) of flour blends, baking quality (bread and

cookies), and digestibility of baked products from blended flour samples. Findings revealed that supplementation with pigeon pea flour increased protein content of the bread and cookie

products. However, incorporation of cassava and pigeon pea flours resulted in significantly

impaired bread quality, such as lowering loaf volume and height. The quality attributes of blended flour cookies were superior to those of control (wheat cookies). The total hydrocyanic

acid content of baked samples was significantly higher when added cassava flour levels increased, though still below the maximum allowable amount of 1 mg/kg. Both carbohydrate

and in vitro protein digestibility decreased as wheat flour was substituted with cassava and pigeon pea flours, but still was above 50%.

Key words: Cassava flour, Pigeon pea flour, physicochemical properties and baking qualities









(ISTRC-AB)

116

Growth performance and cost benefit of growing pigs fed cassava peel Meal-

Based Diets Supplemented with Allzyme® SSF

Adeyemi, O. M., *Irekhore O. T., Idowu, O. M. O. and Akinola, O. S.

College of Animal Science and Livestock Production

Federal University of Agriculture, Abeokuta, Nigeria.

*[email protected]

Abstract

Feed cost accounts for 60-80% of the total cost in pig production and the increasing costs of energy ingredients, especially maize, has necessitated the use of alternative energy feedstuff.

An experiment was conducted to investigate the effects of replacing maize with cassava

peel meal (CPM) supplemented with Allzyme ®SSF on the growth and cost analysis of growing pigs. Chemical composition of the CPM used was determined using standard

procedures. Twenty-four growing pigs of 10 weeks old with average weight of 14.0 + 0.75 kg were allotted to 6dietary treatments where CPM replaced maize at 0, 50 and 100% levels

with SSF supplementation at 0g/100kg and 20g/100 kg diets. Each treatment was replicated 4 times while the experiment lasted 8 weeks. Data were collected on final body weight, total

feed intake, feed conversion ratio, daily weight gain, daily feed intake, feed cost/weight gain

and feed cost/day. The dry matter, crude protein, crude fibre, crude fat, nitrogen free extract, crude ash, gross energy, neutral detergent fibre, acid detergent fibre and hydro cyanide

contents of the CPM were 88.30%, 5.51%, 9.70%, 1.42%, 4.87%, 3,577.7Kcal/kg, 10.44%, 13.24% and .03mg/100kg, respectively. CPM based diets gave comparable (P>0.05) pigs’

growth performance as did the maize based diets. Feed cost/day reduced significantly(P<0.05) with inclusion of CPM in the diet of pigs while enzyme supplementation of diets did not

influence (P>0.05) pigs’ growth performance and cost benefit.CPM supplemented with

Allzyme® SSF can wholly replace maize in the diet of growing pigs to reduce cost with optimal performance.

Key words: Allzyme SSF, cassava peel meal, growth performance, cost analysis



(ISTRC-AB)

117

2 3

Effect of storage temperature and time on the functional properties of high

quality water yam flour

1*Owo, H.O., 1Adebowale, A.A., 1Sobukola, O.P., 1Obadina, O.A.,1Kajihausa,


Abeokuta, Nigeria. 2Department of Food Service and Tourism, Federal University of Agriculture, Abeokuta, Nigeria.


Abstract

The effect of storage temperature and time on some functional properties of high quality water yam flour produced from water yam slices soaked in 0.28% (w/v) K SO was

investigated. The samples were packaged in high density polyethylene (HDPE) and stored

at three temperatures (25±2, 35±2 and 45±2 oC) and at a single relative humidity (36%) for a period of 8 weeks. The functional properties (bulk density, water absorption index, water

binding capacity, wettability, oil absorption capacity) of the samples were determined at the initial and final week of storage. Data obtained were subjected to analysis of variance to

obtain the main and interactive effects of storage temperature and time. Result obtained showed that mean values of bulk density, water absorption index, water binding capacity, oil

absorption capacity and wettability ranged between 0.76 and 0.80 g/ml, 1.70 and 2.24, 71.91 and 128.00 %, 0.18 and 0.53 and 52.54 and 63.50 respectively. The effect of storage time

was significant (P<0.05) on all the functional properties while the effect of storage temperature

was not significant (P>0.05). The interactive effect of storage temperature and storage time was not significant on all the functional properties (P>0.05). Hence, the results obtained

show the possibility of using high quality water yam flour industrially subject to storage time.

Keywords: High quality water yam flour, storage temperature, storage time, functional properties



(ISTRC-AB)

118

Applications of experimental auction mechanisms and sensory evaluation

methods to understand consumer acceptance of biofortified yellow cassava in

Nigeria

Adewale Oparinde 1, Abhijit Banerji2 and Ekin Birol1

1International Food Policy Research Institute, Washington, DC, USA 2Delhi School of Economics

[email protected]

Abstract

In this paper we use the Becker-deGroot-Marschak auction mechanism to estimate consumer demand for biofortified yellow cassava varieties in two states of Nigeria: Imo in the Southeast

and Oyo in the Southwest. These two states exhibit distinct habitual product colour preferences for staple food made with cassava. We estimate the effect of nutrition information campaign

and consumer trust in two alternative planting material delivery institutions on consumer demand. Results suggest that consumers have significant premiums for biofortified yellow

cassava varieties. In the Southwest light yellow biofortified cassava varieties can compete favourably with local white ones, even in the absence of nutrition information. Nutrition

information results in a significant price premium for biofortified yellow cassava in both

states, and also results in an unexpected positive externality by reducing consumers’ disutility for government delivery authority due to their low trust therein.



(ISTRC-AB)

119

Physical and sensory properties of extruded snacks from high quality cassava -

tigernut composite flour

1*Kareem, S.T., 1Sobukola, O.P., 1Adebowale, A.A., 1Obadina, O.A.,1Kajihausa,



3Natural Resources Institute, University of Greenwich, United Kingdom

*[email protected]

Abstract

The physical and sensory properties of extruded snacks from high quality cassava flour (HQCF) and tigernut flour were investigated. Extruded snacks were produced from different

blends of HQCF and tigernut flour at the ratios of 90:10, 80:20, 70:30, 60:40, 50:50, 40:60,

30:70, 20:80 respectively and unblended samples (100% HQCF and tigernut flour) serves as control. The extrusion experiments were carried out using a single screw laboratory extruder.

The samples were extruded using feed moisture, screw speed and barrel temperature of 27%, 60 rpm and 80 ºC, respectively after series of experimental trials. The feed samples

were preconditioned prior to extrusion with hot water (80-90°C) to uniformly hydrate the raw material in order to eliminate any dry core. Extrudates were analysed for physical

properties (expansion ratio, bulk density, colour and breaking force) while sensory attributes were determined using quantitative descriptive analysis (10 trained panelist). Data obtained

were subjected to analysis of variance (ANOVA). The physical properties of the extrudates

show that the expansion ratio, bulk density, colour intensity and breaking force ranged from 1.30 to 2.74, 0.17 to 0.27 g/cm3, 1.91 to 8.31 and 0.64 to 21.84 N respectively. Breaking

force decreases as the level of tigernut flour increases probably due to the fat content of tigernut flour while the colour difference (“E) of the extrudates increases with increase in

tigernut flour. Sensory analysis result showed that increasing tigernut flour resulted in increased colour and taste (sweetness) of the extrudates which may be due to the natural sugar content

of tigernut while the texture decreases with increase in tigernut flour which is due to the fat

content of tigernut. Significant differences (p<0.05) were observed in the physical and sensory properties of the extrudates. The study showed that high quality cassava flour and tigernut

flour from the different blends could be used to produce quality extrudates with acceptable sensory properties.

Key words: Extrusion, High quality cassava flour, tigernut flour, physical and sensory

properties.



(ISTRC-AB)

120

Physical and functional properties of fermented cassava flour (lafun) obtained

from different markets in Southwest Nigeria

*Adebayo-Oyetoro, A. O1., Oyewole, O. B2., Obadina, A.O2. and Omemu O.M2

1Yaba College of Technology, Department o f Food Technology, Yaba, Lagos, Nigeria 2Federal University of Agriculture, Department of Food Science and Technology, Abeokuta,

Ogun State, Nigeria

[email protected]

Abstract

The physical and functional properties of fermented cassava (Manihot esculenta Crantz) flour (lafun) from 10 different sources in Southwest Nigeria were evaluated by standard

methods. The fermented flour was collected in polyethylene bags (500g) each from the

markets and transferred to the laboratory of the Department of Food Technology, Yaba College of Technology, Lagos, Nigeria to determine these properties. The results obtained

showed total weight of the foreign matter (including animal droppings, feathers, insect parts, hair and stones) varied from 25%-42%, the water absorption capacity varied between 70.58%-

83.5%, the swelling power which is the amount of water absorbed by 1g of flour ranged from

26.80 (g of water/g)-30.10 (g of water/g) while the bulk density ranged from 0.29mg/ml- 0.60mg/ml. All these results showed that the traditional method of processing fermented

cassava flour (lafun) in Southwest Nigeria has significant effect on the properties measured and these have effect on the quality of this product. Hence, the need for proper awareness

on good manufacturing practices among the traditional processors.



(ISTRC-AB)

121

Functional and pasting properties of wheat–brewers’ spent cassava flour blends

1*Omidiran, A. T., 1Sobukola, O.P., 2Sanni, S. A.1 Adebowale, A.A., 1Obadina,

O.A.,1Kajihausa, O.E., 3Adegunwa, M.O., 1Sanni, L.O., 4Tomlins, K, 5Wolfgang

Tosch 1Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria. 2Department of Nutrition and Dietetics, Federal University of Agriculture, Abeokuta, Nigeria.

3Department of Foodservice and Tourism, Federal University of Agriculture, Abeokuta, Nigeria. 4Natural Resources Institute, University of Greenwich, United Kingdom

5SABMiller PLC, Woking, Surrey, United Kingdom

*bukolaaboderin@yahoo .com

Abstract

This study investigated the functional and pasting properties of wheat – brewers’ spent cassava flour blends. Brewers’ cassava mash was dried at 70 oC for 16 hours to obtain the

flour. Blends from wheat flour (WF) and brewers’ spent cassava flour (BSCF) were prepared at ratios of 80:20 (WF: BSCF), 70:30 (WF: BSCF), 60:40 (WF: BSCF), 100% BSCF and

100% WF. The functional (water absorption capacities, oil absorption capacities, bulk densities, wettability and dispersibility) and pasting properties (pasting temperature, peak, final,

breakdown, trough, setback viscosities and peak time) of the blends were determined and data obtained were subjected to analysis of variance (one-way anova). The mean values for

water absorption capacities, oil absorption capacities, bulk densities, wettability, least gelation concentration and dispersibility ranged from 84.20 – 309.76%, 96.05 – 138.24%, 0.67 – 0.77

g/ml, 19 – 109.5 seconds, 2.00 – 8.00% and 30 – 75% respectively. Pasting properties of the

blends range as follows; the pasting temperature (88.45 – 90.90), peak viscosity (7.96 – 64. 79), final viscosity (6.54 – 93.17), breakdown (2.71 – 24.46), trough (5.25 – 40.33), setback

(1.29 – 52.83) values in rapid visco units and peak time (5.00 – 5.57). The pasting temperature of brewers’ spent cassava flour showed error due to the fact that the flour did not form a

paste. There were significant differences in the functional and pasting properties of the blends (P< 0.05).This study established the functional and pasting properties of wheat -

brewers’ spent cassava flour blends and that it has a lot of potential in the food industry

especially its use as thickener and binding agent in the food systems.

Key words: Brewers’ spent cassava flour, wheat flour, functional and pasting properties



(ISTRC-AB)

122

Nutritional composition and diversification of the use of D. rotundata varieties in

Fako Division of Cameroon.

Achidi Aduni Ufuan, Ikome Evelyn Mesaka, Forba Josepha Tendoh and Dopgima

Levai

Department of Biochemistry and Molecular Bio logy, Facu lty of Science, University of Buea

Abstract

Of all the root and tuber crops, white yam ranks third in Cameroon but with little or no

transformation. Nutrient information and diversification will increase culinary use, storability and economic value. In the Fako Division five varieties are predominantly grown; Batoke

Aga, egbe, Muyuka and Sandpaper. The objective of this work was to evaluate the nutrient content and diversify the use of white yams in the Fako Division. Five varieties of D. rotundata

were characterized, their functional properties determined and local products made for an

organoleptic evaluation. All data obtained were subjected to statistical analysis at Pd”0.05.There existed a significant difference in the proximate composition except in the

lipid content. The moisture content ranged from 64.16% for Muyuka to 71.86% for Egbe. Ash and protein contents ranged from 1.75% and 2.53% for Muyuka and 3.30% and 6.75%

for Egbe respectively. The sugar content ranged from 0.32% for Batoke to 3.09% for Sandpaper. The starch content ranged from 42.75% for Egbe to 60.10% for Batoke. The

crude fiber content ranged from 0.16% for Batoke to 0.87% for Muyuka. There was also a

significant difference of (Pd”0.05) in the functional properties with solubility index ranging from 7.10% for Muyuka and 11.22% for Batoke. The swelling Power ranged from 10.78%

for Egbe and 13.12% for Batoke and water Binding Capacity ranged from 103.64% for Batoke to 185.73% for Muyuka. There was no significant difference (PÃ0.05) between the

mineral content and the pasting properties but there existed a trend. There was no significant difference (PÃ0.05) among the products made from the varieties for amala and pounded

yam except in the case of colour and appearance respectively. Pounded yam had a significant (Pd”0.05) preference over amala.


(ISTRC-AB)

123

Quality indices of cassava starch as affected by variety and maturity age

1*Adegoke, Adekola and 2Adekoyeni, Oludare

1Production and Engineering Department, Psaltry International Limited, Alaide/Wasinmi

Village, Ado Awaye, Oyo State, Nigeria 2Food Science and Technology Department, The Bells University o f Technology, Ota,

Ogun State, Nigeria

*[email protected]

Abstract

Cassava (Manihot esculenta) is of varying usage globally. In Nigeria, it is processed into staple foods such as gari, fufu, flour, starch, and of recent glucose syrup. In this study, four

varieties of freshly harvested cassava tubers (TME 419, TMS 0068, TMS 326, TMS 30572) at maturity age ( 8-12) months were peeled by abrasion, washed, chopped and rasped. The

starch content of TME 419, TMS 0068, TMS 326, TMS 30572 roots were 21-30% and dry

matter was 26-35.1% at age 8-12 months. The rasped tubers were mixed with a lot of membrane treated water. The resultant slurry was extracted, refined, vacuum pressed and

flash dried at 700 C. The dried starch was sifted and kept in air tight containers for analysis. The quality indices determined were moisture content (11-12%), degree of whiteness (82-

88Wb), starch content (21-30%), Baume (21-22ÚBe)and pH (6-7). Engineering properties which include density, specific heat capacity, thermal conductivity, thermal diffusivity, WAC,

amylose/amylopectin ratio of cassava starch were investigated using proximate composition

based empirical models and Juliano methods. From the data obtained, it was found that density of cassava starch is (526±0.10)Kg/m3, specific heat capacity (942±0.05)(KJ/Kg K),

thermal conductivity (0.12±0.02)W/mÚK, thermal diffusivity (2.42x10-7±0.01)m2/s, Peak viscosity (290.58±0.01)Ns/m2, setback viscosity (179.58±0.03) Ns/m2, amylose/amylopectin

ratio (0.36±0.01), SP (6.83±0.03)%, WAC (94.49±0.04)% and SI (6.83±0.03). The values obtained for thermo physical and rheological properties were found to be useful in the design

of extraction and refining process for cassava starch while the quality indices determines the

consumers’ acceptability of cassava starch.

Keywords: Engineering properties, sift, rasp and quality indices.



(ISTRC-AB)

124

Pasting properties of flours from high-dry matter sweetpotato (ipomoea batatas l.)

varieties: the influence of crop maturity

1Adu-Kwarteng, E., 2Esther Sakyi-Dawson, 3Fred F. Shih, 3Kim Daigle

and 4Van-Den Truong 1Crops Research Institute, P. O. Box 3785, Kumasi, Ghana – West Africa;

2Dept. of Nutrition & Food Science, University of Ghana, P.O. Box 25, Legon, Ghana- West Africa; 3USDA-ARS-SRRC, New Orleans, LA 70124, USA

4USDA-ARS, SAA Food Science Research Unit, Dept. of Food Science, North Carolina State

Univ., Raleigh, NC 27695-7624, USA

Abstract

Sweetpotato, fast-growing and highly nutritious, can play a key role in the food security of many under-nourished communities in West-Africa. Persistent low utilization is however

linked with lack of understanding about factors determining product quality of different cultivars.

Effects of maturity and short-term storage on RVA pasting properties of sweetpotato were determined for flours prepared from four cultivars harvested at 3, 4 and 5 months after

planting. Peak viscosity for freshly harvested roots ranged from 97.58 to 458.33 RVU, was highest at 4 months in all the cultivars and varied significantly with maturity (p<0.01). In

stored samples maturity significantly affected Peak time (p<0.01); Stability ratio was lowest at 4 months in all cultivars, especially after storage. When amylase enzyme activity was

inhibited, RVA pasting properties were very different from those of enzyme-active flour,

revealing drastic effects of amylase action that occur during cooking of sweetpotato. Estimated amylase activity was found to vary significantly with maturity (p<0.05). These results indicate

that maturity significantly affects cooking characteristics in the cultivars studied. This information is relevant in the promotion of sweetpotato utilization and contributes to better

understanding and control of product quality, both domestic and industrial.

Keywords: RVA pasting properties, sweetpotato flour, maturity, amylase enzyme activity


(ISTRC-AB)

125

Proximate composition and sensory evaluation of prawn crackers made from sweetpotato (Ipomoea batatas) starch

*Kajihausa O. E. and Esenwa J. O

Department of Food Science and Technology Federal University of Agriculture, Abeokuta,

P. M. B. 2240, Abeokuta, Nigeria.

*[email protected]

Abstract

Sweetpotato (Ipomoea batatas) is a hardy and nutritious staple food crop, which is grown throughout the humid tropical and subtropical regions of the world. In Africa, it is the third

most important root crop after cassava (Manihot esculenta) and yam (Dioscorea spp). Sweetpotato is considered an excellent food security crop in sub-Saharan Africa because it

often survives when other crops (for example, maize) fail. It is used in a variety of forms; it can be boiled, steamed, baked, fried, chipped, candied, canned, frozen, made into flour or

starch, and processed into a number of products. Sweetpotato outranks most root crops in vitamins, mineral and energy contents. In spite of the tremendous agronomic and nutritional

advantages of sweetpotato, it is underutilized in West Africa compared to other root crops

(e.g. cassava and yam), due to several factors such as sweetness and texture and high perishability of the roots. This study was therefore conducted to determine the proximate

composition and sensory evaluation of prawn crackers made from two varieties (yellow- fleshed and white-fleshed) sweetpotato starch using the conventional prawn crackers as a

control. There were significant differences (p<0.5) in the proximate composition of the prawn cracker samples except the crude fiber. The values of the protein content, moisture content,

ash content, crude fat, crude fiber and carbohydrate content of the prawn cracker samples

ranged from 14.88±18 - 16.69±16, 5.98±19 – 6.71±07, 3.98±22 – 4.96±22, 10.19±02 - 11.79±25, 7.89±25 – 8.40±22 and 53.39±09 – 55.69±18, respectively. Significant differences

(p<0.05) were observed in all the sensory attributes investigated except texture. The prawn cracker sample produced from the yellow-fleshed sweetpotato starch had higher values for

all the sensory attributes (colour, taste, flavor, texture, crispiness, appearance and overall acceptability) when compared to samples produced from white-fleshed sweetpotato starch.

Prawn crackers of desirable sensory attributes were produced from sweetpotato starch.

The use of sweetpotato starch in prawn cracker production would enhance the utilization of this crop in sub-Saharan African countries.

Keywords: Sweetpotato, Starch, Prawn crackers, Proximate composition and Sensory

evaluation.



(ISTRC-AB)

126

Nutritive value of four cassava varieties and their effects in brioler rations

1Tewe O. O., O.A. 1Abu, 2I. Andrew, 2P. Iluebbey, and 3M. A. Mosobalaje, 2P.

Kulakow 1Department of Animal Science, University o f Ibadan, Ibadan, Nigeria.

2Cassava Breeding Unit, International Institute of Tropical Agriculture, Ibadan, Nigeria. 3Oyo State College of Agriculture, Igboora. Oyo State, Nigeria.

Abstract

Dustiness and microtoxins limit the use of cassava particularly in poultry rations. Cassava grit is a gelatinized product similar to pellets. Four varieties of cassava comprises TMS 01/

1371 (High carotene), TMS 08/8693 (high protein), TME 419 and TMS 30572 (conventional varieties).

Whole cassava storage roots of the four varieties were washed, detailed, grated, dewatered, fried and labeled as cassava grit. Proximate analysis of the four cassava grit samples was

carried out and True Metabolisable Energy (TME) was determined using force feeding techniques on 10 weeks old broilers. Cassava grit samples except TMS 08/8693 were used

to replace 50% maize in the diet of broilers. Proximate values of the four cassava samples

varied significantly. Crude protein and True protein of TMS 08/8693 were 3.05% and 1.42% and significantly higher than the other samples. Fibre content of TMS 30572 (3.42%) was

the lowest and significant (p<0.05) as compared to others. True Metabolisable Energy of the four cassava samples were similar (P> 0.05). Performance was not significantly affected by

the dietary treatments. However, cost/weight gain was lower for diets containing cassava grit (¦ 163.97, ¦ 162.25 and ¦ 163.67 for TME 419, TMS 01/1371 and TMS 30572 respectively)

compared to control the diet ¦ 181.28. Serum thiocyanate of broilers fed cassava based diets was higher than value recorded for those broilers fed control diet (1.98mg/dl). High protein

content of TMS 08/8693 validated the claim as a high protein variety. Partial (50%)

replacement of maize with cassava grit did not affect performance and economy of production of broilers.

Key words: Broiler, Cassava grit, Serum thiocyanate, True metabolizable energy and True

protein.


(ISTRC-AB)

127

Microbial Hazard and Hazard Analysis Critical Control Points in “Gari”

Production System

M.O. Ekop 1, O.E.Ekop2

1Family Unity for Sustainable Development Foundation, NCRI, Ibadan, Nigeria 2Merbot Consult International Limited, NCRI Compound, Ibadan, Nigeria

fusd [email protected] , [email protected]

Abstract

Hazard Analysis Critical Control Points (HACCPs) strategy identifies hazards associated with different types of foods manufacturing and handling, assess related risk and identifies

points where control measures would be effective. The objective of the study was to assess

relative risk and identify critical limits where Critical Control Points (CCPs) could be effective in “gari” processing system. Interviews, participatory observation, food safety standards and

laboratory investigation were used to determine manufacturing practices, food handling and CCPs for microbial hazards in the studied cassava tuber processing into “gari” system.

Critical limits of microbial hazards in raw, fermentation and finished product stages from farm-to-table: raw and fermentation stages – ASB, Klebsiella spp and Diphtheroid spp. at

5.0 x 106 cfu/g, Bacillus spp. at 104 cfu/g and Escherichia coli at 103 cfu/g; and finished

product, ASB, Klebsiella spp. Diphtheroid spp. Bacillus spp. at 104 cfu/g, and no Coliform in finished products. Five steps were identified in raw processing stage, four steps in

fermentation stage and one step in finished product stage. Inputs from risk factors were industry water, environment, processing equipment and processors/food service personnel.

The mean microbial load in raw “gari” processing stage and CCPs measures were established at: unpeeled cassava tuber – Escherichia coli at 1.3 x 104 cfu/g; Peeled cassava tuber –

Escherichia coli 1.3 x 104 cfu/g. At fermentation stage, CCPs were established at cassava

mash before sieving with Bacillus spp. at 1.5 x 104 cfu/g, and finished product stage with Diphtheroid Bacillus at 1.4 x 104. At input levels, CCPs were established at Environment -

industry water - Escherichia coli at 1.3 x 103 cfu/g, Effluent from pressed cassava paste - Bacillus spp. at 7.5 x 104 cfu/g, ground air measurement of the “gari” processing environment

for 30 minutes with blood agar - Bacillus spp. at 5.5 x 105 cfu/g; at “gari” processing equipment - body of presser machine – Bacillus spp. at 1.5 x 106 cfu/g, Staphylococcus

aureus at 5.2 x 106 cfu/g; Presser - Bacillus spp. at 1.2 x 104 cfu/g, “gari” frying equipment

- “gari” pot before cleaning - Bacillus spp. at 1.4 x 104 cfu/g. At stage of finished product, read-to-eat fried “gari” CCP was established with Dephtheroid bacilli at 1.4x104 cfu/g.

Compliance with Good Manufacturing Practices (GMP) and Good Hygiene Practices (GHP), correct critical limit and Critical Control Points for microbial hazards in “gari” product is

stressed.

Keyword: Cassava, Processing, microbial hazards, HACCP, Relative risk, Critical limits,

CCPs.





(ISTRC-AB)

128

Analysis of opportunities for improving the efficiency of Ghanaian cassava

processing industries through introduction of selected Indian technologies.

J.Thajudhin Sheriff1, Nanam Tay Dziedzoave 2, Benjamin Addi Okae 2, Keith

Tomlins3

1.Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram, India

2.CSIR-Food Research Institute, Accra, Ghana

3.Natural Resources Institute, University o f Greenwich, Chatham Maritime, ME4 4TB, United

Kingdom

Abstract

Ghana is the sixth largest producer of cassava in the world with a production of 14.5 million tonnes from 0.9 million hectares of land. About 3.7 million tonnes of surplus tubers are

available for industrial utilisation. The processing industries producing cassava chips, cassava flour, (Kokonte Lafu), fermented cassava flour, fermented cassava-corn flour mix (Banku

mix), wet cassava cake and cassava starch were visited and collected details for improving the efficiency of industry and product quality. Samples collected for quality evaluation showed

that the HCN level in dried cassava chips was very high (13.2mg.100g-1) than other samples. The major constraints in the processing industries are lack of supply of tubers, frequent

power failures, drudgery in peeling and thin slicing of tubers, limited batch type dewatering

process and drying. The methods of supply chain management adopted in some Indian starch industry will be useful for increasing the capacity of Ghanaian starch factories.

Modification and introduction of some technologies available in Indian cassava processing industries such as continuous mechanical peeling, continuous thippi presses for dewatering

process, and solar dryers will have impact in product quality and efficiency of industry. It was observed that no industry is treating the effluent and there is a possibility of converting

the effluent as an energy source through biomethanation.


(ISTRC-AB)

129

B

6

6

Effect of variety and processing methods on the antinutritional and vitamin

contents of high quality yam flour (HQYF)

1*Wahab, B.A., 1Adebowale, A.A., 1Sobukola, O.P., 1Obadina, O.A.,1Kajihausa,




Abstract

In this study, the effect of variety, pretreatment and drying methods on antinutritional and

vitamin contents of high quality yam flour (HQYF) was investigated. Four varieties, using

two pretreatment methods (soaking in 0.28% potassium metabisulphite for 15 min and blanching in hot water at 70ºC for 15 min) and two drying methods (cabinet at 60ºC for 24 h

and open sun drying for 2 days) using a 4×2×2 factorial design. Data obtained were statistically analyzed and means with significant differences were separated at 5% level. Samples were

analyzed for phenol, tannin, phytate, saponin, alkaloid, oxalate, vitamin B , vitamin B , vitamin 1 2

and vitamin C using standard procedures. The main and combined effects of variety, pretreatments and drying methods on the antinutritional composition of the HQYF samples

were significant (p<0.05) except for saponin which pretreatment had no significant (p>0.05) effect on. The low level of alkaloid (0.21g/100g) and phytate (13.43g/100g) in HQYF sample

from D. rotundata in this study underscore its safety and availability of minerals for absorption

in the body when consumed/used as food formulations. The vitamin contents of the HQYF samples ranged from 0.18-1.05 mg/100g (vitamin B ), 0.44-4.55 mg/100g (vitamin B ), 2.00-

1 2

4.34 mg/100g (vitamin B ) and an appreciable quantity of vitamin C (20.87-30.91 mg/100g) was detected in all the HQYF samples. From the analysed results, the main effect of variety as well as interactive effects of variety, pretreatment and drying method significantly (p<0.01)

affect the vitamin contents of HQYF. The appreciable level of vitamins observed in HQYF

could indicate product of good nutritional quality for the consumers.

Keywords: Yam, Dioscorea sp., anti-nutritional composition, vitamin contents



(ISTRC-AB)

130

Cassava whey- a potential source of Citric Acid

Kareem S.O1*, Oladipupo I. O1., Omemu, A. M.1 and Babajide J. M.2

1Department of Microbiology, University of Agriculture, Abeokuta, P.M.B.2240, Abeokuta,

Ogun state, Nigeria 2Department of Food Science and Technology, University of Agriculture, Abeokuta, P.M.B. 2240,

Abeokuta, Ogun state, Nigeria

*[email protected] .uk

Abstract

The potential of cassava waste water as a medium for the production of citric acid was evaluated. Citric acid producing strain of Aspergillus niger was cultured on cassava whey

medium at 30 oC for 10 days. The medium was supplemented with various carbon sources and nitrogen sources. Also effects of alcohols, metal ions and inhibitors on citric acid yield

were evaluated. The results indicated that cassava whey medium containing glucose (5%w/

v) and Ammonium phosphate (0.25%w/v) gave optimum citric acid yield (55g/L) under agitated conditions. Methanol (1%) stimulated citric acid production .Enhanced citric acid yield was

also obtained in the presence of Mn2+ and Zn2+ while glycerol and phenol exhibited inhibitory effects. The study therefore converts cassava whey to a commercially valuable organic acid

and also reduces its disposal problems.

Keywords: Cassava whey, citric acid, Aspergillus niger



(ISTRC-AB)

131

Food Safety Level Assessment in Cassava Tubers Processing into “Gari”.

Ekop M.O. +*, Ekop O.E +X

+ Family Unity for Sustainable Development Foundation (FUSDF), NCRI compound, Moor

plantation, Abeokuta road, Ibadan, Nigeria X Mebort Consult International Limited, Moor plantation, Ibadan, Nigeria

[email protected] ; [email protected]

Abstract There is a growing need to utilize the new Hazard Analysis Critical Control Points (HACCPs) system to enhance safety. The concept of HACCPs strategy coupled with Good

Manufacturing Practice (GMP) and Good Hygiene Practices (GHP) is to ensure that food of high quality is processed and produced. This study was to determine food safety levels in

cassava tuber processing into “gari”. One processor in gari processing industry was selected

from 20 screened processors in a multi-stage sampling technique. This study was conducted in Onipepeye, Oremeji Agugu cassava processing industry in South west geo-tropical region,

Nigeria. 14 samples collected from the processing steps of raw, fermented and finished (ready - to - eat) product stages from farm – to - table in 2 visits were analyzed for biological

contaminants and safety assessment. Proportions of bacteria count within upper and lower tolerant level for raw products and keeping to standard range for finished products were

used to determine food safety in “gari” processing chain. In raw cassava processing stage, the steps of unpeeled cassava tuber and peeled cassava with mean bacterial count (cfu/g)

1.2 x 104 and 1.3 x 104 respectively as against a raw standard range (cfu/g) of 103 made the

product unsafe in these steps. At fermentation processing stage, Bacillus spp mean count of 1.0 x 104 cfu/g and 1.5 x 106 cfu/g atsteps of cassava mash before sieving and sieved

cassava mash respectively, as against a safety range of 104 cfu/g make the steps unsafe. Diphtheroid bacilli with mean count of 1.4 x 104 cfu/g in finished ready –to - eat “gari” as

against the safety range of 104 cfu/g for finished product makes the gari unsafe for human consumption. Analysis of biological contaminants along “gari” processing chain used for

safety assessment in the study, showed that the proportion “gari” processing steps in the 3

stages accepted was lower than those rejected based on standard range. Of greater importance to the study was the rejection of the final “gari” (ready-to-eat) product.

Key words: Food safety, cassava food processing, “gari” , Standard range, Industry,

biological contaminant.






(ISTRC-AB)

132

AGRONOMY

Productivity and field disease reaction of biofortified cassava genotypes in Nigeria

Bello, A.A.1,2, Parkes, E.1, Aina, O.O.1, Maroya, N.G1, Kolawole, R.2, Akoroda, M.O.2, Kulakow, P.1,*

1International Institute of Tropical Agriculture (IITA), Ibadan. 2 Department of Agronomy,

University of Ibadan, Ibadan, Nigeria.

[email protected], [email protected], [email protected], [email protected],

[email protected], [email protected], [email protected].

*Correspondence author: p [email protected]

Abstract

The objective of this study was to assess the productivity of some improved cassava genotypes for fresh root yield, total carotenoid content, dry matter content, dry yield, number of roots per plot, harvest index and their field reactions to cassava mosaic disease (CMD) and cassava

bacteria blight (CBB). Twelve improved proVitamin A enhanced cassava (Manihot esculenta

Crantz) genotypes along with two checks were evaluated for two years in three agro-ecological zones in Nigeria. The experimental design was a randomised complete block design with

four replications. Differences (p < 0.001) were observed among genotypes for all traits. Partitioning of variance components revealed that genotype by location contributed largely to

the total variation observed for genotype by environment interaction (G X E) for all the traits. Genotypes and locations effects were also significant. Genotypes TMS-IITA-IBA062116,

TMS-IITA-IBA061856 and TMS-IITA-IBA061404 showed high tolerance to CBB and CMD

infections. Genotypes TMS-IITA-IBA062116, TMS-IITA-IBA30572 and TMS-IITA- IB061577 were highest for fresh root yield across the three agro-ecological zones.

Keywords : biofortified, productivity, disease reaction, proVitamin A, agro-ecological zones.











(ISTRC-AB)

133

Evaluation of different animal manures as plant nutrient sources on the production of cocoyam (colocasia esculenta) in inland valleys of Southeastern

Nigeria

Nwite, John C. 1, Okolo, C. Chukwuebuka2*, Igwe, Charles A.2, Ezeaku, Peter

I.2., Chukwudi, P. Uchechukwu.3, Nwite, James N.4., Okenmuo, Frances C.2,

Agbo, Emmanuel A.5 and Umeugochukwu, Obiageli P.6

1Department of Crop Production, Federal College of Agriculture, Ishiagu, Ebonyi State, Nigeria 2Department of Soil Science, University of Nigeria, Nsukka, Nigeria

3Department of Crop Science, University of Nigeria, Nsukka, Nigeria 4Department of Soil and Environmental Management, Ebonyi State University, Nigeria

5Department of Agronomy, Michael Okpara University Umudike, Abia State, Nigeria 6 Department of Soil Science, University o f Stellenbosh, South Africa

* [email protected]

Abstract

The soils of Ebonyi State, South-eastern ecological zone of Nigeria are plagued with characteristics that impede optimal crop production. In order to arrest the declining productivity

of the degraded soils in this zone, an appropriate soil management practices are needed. Nigerian farmers’ access to fertilizer in growing season is limited by fund. Scarcity and late

distribution are the major problems to the optimum production of most crops like roots and tubers. It is therefore necessary to source for locally available, cheap and environmental

friendly materials that can be used for crop production. An investigation to evaluate the

influence of animal manures (poultry droppings, cattle dung and pig dung), including the control, as plant nutrient sources on the growth and yield of cocoyam (Colocasia esculenta),

was carried out in an inland valley at Federal College of Agriculture, Ishiagu, Ebonyi State. The treatments were fitted into a randomized complete block design (RCBD) with three

replications. Each of the treatment was applied at the rate of 10 tons/ha and were incorporated into the soil two weeks before planting. The planting materials used were the cocoyam

cormels planted on 0.75 metre raised beds. The weight of the cormels used for the research was not consistent, but ranged between 140 – 150 grams. Plant height was measured on

weekly basis and yield at the end of the experiment. Data were analyzed using GenStat3 7.2

Edition. Treatment means were separated using Least Significant Difference (LSD) at 5% probability level. The result showed that poultry dropping significantly (p < 0.05) improved

the yield by 6 ton/ha over the control plot. Poultry dropping also gave a significantly (p < 0.05) higher plant height at 4th, 6th, 7th, 8th and 12th week after planting than the other

amendments including the control.

Keywords: Cocoyam, animal manures, inland valleys, cormels, soil management



(ISTRC-AB)

134

Effects of nitrogen sources on soil carbon sequestration in Southeastern Nigeria

N.R.,Njoku1, O.A. Opara – Nadi 2 and O. Eke- Okoro1

1National Root Crops Research Institute Umudike. 2Abia State University Uturu.

nwanyiezern [email protected]

Abstract

Sequestration of soil organic carbon from nitrogen (N) sources is a key sequestration pathway in agriculture offering mitigation for other agriculture’s green house gas emissions.Field

experiment were conducted at Umudike location, Nigeria, during the 2009 and 2010 cropping seasons to determine the effects of nitrogen (N) sources on soil carbon sequestration (SOC)

undermaize and cowpea grown in rotation. The experimental design was a randomized

complete block (RCB) design with three replications. The N sources, each applied at the rate of 120 kg ha-1 were urea (UR), sawdust (SD), poultry dropping (PD), Cow dung (CD),

brewers’ spent grains (BS), pig manure (PM) and combination of the entire organic N sources (CB). Soil samples were collected before establishing the experiment and after field operations

from 0 – 10, 10 – 20 and 20 – 40 cm depths in all the plots to determine soil carbon content and storage. Total Carbon content andstorage in the 0 – 40 cm depth of the experimental

site before treatment application in 2009 was 24.6gkg-1 and 45.6 mg ha- 1

respectively.Significant differences in carbon content and storage were observed for the N sources in all these depths during the two years. The observed values of SOC content and

SOC storage for the whole profile, 0 – 40 cm depth ranges from 24.5 g kg-1 for CT to 31.7 g kg-1 for SD and from 49.0 Mg ha-1 for CT to 63.7 Mg ha-1 for BS respectively.After two

cropping seasons, the BS treatment had the highest C storage (stock) for the entire soil profile (0 – 40 cm) depth and therefore could be recommended.



(ISTRC-AB)

135

Yield and P use efficiency of two cassava genotypes under different P levels in a

derived savanna of South West Nigeria

V.O. Aduramigba-Modupe 1*, A.O. Aduramigba-Modupe 2 and S. Olanipekun1

1Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation,

PMB 5029, Ibadan, Nigeria 2Department of Crop Protection and Environmental Biology, University of Ibadan,

Ibadan, Nigeria * [email protected]

Abstract

Phosphorus deficiency is a widespread fertility constraint of many tropical soils. Low available

P in these soils has been associated with high contents of Fe and Al oxides which readily fix soil solution. Two years field experiment were conducted in the derived savanna of Nigeria

in an Alfisol, locally classified as Fashola series to evaluate the response of two cassava genotypes to P addition using the fractional recovery P model. The two varieties (TMS 01/

1412 and TMS 01/1368) and three P rates (0, 30 and 60 kg/ha) were arranged as a split plot

in a randomized complete block design, with three replications. Varieties showed differences in root yield to P fertilization. TMS 01/1412 significantly (P>0.05) produced maximum root

yields of 35 t/ha across P rates in both years and had the highest P use efficiency. The varieties showed significant tolerance to native P fertility suggesting they are efficient in

utilizing native soil P for root production.

Keywords: Cassava, phosphorus, soil, root yields.



(ISTRC-AB)

136

Effects of slope position, urban refuse compost and sewage sludge on soil

properties and cassava yield in South Eastern Nigeria

Ezema Raymond A, Obi M.E, Asadu C.L.A.

Department of Agricultural Technology Enugu State College of Agriculture and Agro-

Entrepreneurship, Iwollo, Nigeria.

Department of Soil Science, University of Nigeria Nsukka.

[email protected]

Abstract

Understanding the effects of slope position and organic waste residues on soil properties and

cassava yield is a critical component of site-specific management. A field study was conducted in an Ultisolat Nsukka, south eastern Nigeria to investigate the effects of slope positions and

two organic wastes residues (urban refuse compost and sewage sludge) on soil properties and cassava yield. The treatment consisted of 2 x 3 factorial combinations; slope position and

organic residues arranged in a split–plot design. The two slope positions were midslope (5%)

and toe slope (1%) while organic residues at the rate of 50% inorganic nitrogen fertilizer requirement of cassava were the sub plots. There was an unamended control. The result

obtained from this study showed that slope position significantly influenced percentage water stable aggregates (% WSA), bulk density and heap leveling of the soil. Significant interactions

of the slope positions and organic residues were observed in bulk density, total porosity, and fresh root yield. The highest fresh root yield of 11.63 t/ha in the study was obtained in plots

amended with urban refuse under the toe slope position which was far below the average

yield of cassava under inorganic fertilizer amended cultivations.

Keywords: Slope position, urban refuse, sewage sludge, Ultisol, cassava.




(ISTRC-AB)

137

Yam minisett intercropping studies for improved productivity of the cropping

systems and soil fertility enhancement

ANO, A. O., ADIELE, J., CHUKWU, L. I. and Nwosu, P. O.

National Root Crops Research Institute Umudike, PMB 7006, Umuahia Abia State, Nigeria

Abstract

National Root Crops Research Institute Umudike in collaboration with Institute of Tropical Agriculture, Ibadan developed a new seed yam production method called the minisett technique

where in small sized cut tuber pieces (varying from 25g – 50g) are used as planting material

as opposed to the traditional practice where seed tubers or cut sett of 100g–150g are planted. Production of seed yams using the minisett requires only 6.33% of the number of mother

tubers needed for the traditional farming systems on per hectare bases. Despite the novel nature of the technology and its economic viability, adoption rate has been found to be low as

a result of its emphasis on mono-cropping. Most farmers in the yam growing zones of Nigeria practice intercropping. For intercropping to be viable, the intercropped crops must be

compatible. This paper reviewed yam minisett based intercropping studies carried out at

National Root Crops research Institute, Umudike, Nigeria over the past decade. The effect of the intercrops on the productivity of the systems and the soil resource-base were examined.


(ISTRC-AB)

138

Effect of weeding regime on the growth and yield of Hausa potato on ultisols of

South Eastern Nigeria. Njoku S.C, A. O. Olojede, D. U. N. Ikeogu, and C.Obasi

National Root Crops Research Institute Umudike Nigeria; Email:

[email protected].

Abstract

An experiment was conducted at NRCRI, Umudike for 2years 2008-2009 to determine the critical period of weed interference on Hausa potato production. Two weeding schemes

were used. In the first schemes, the crops were kept weed free for specific period and after allowed to be under weed for the rest of the growth period while on the second scheme, plots

are kept weedy for a period and thereafter weeded for the rest of the crops growth period.

Result for Hausa potato showed that yield increased as the plots were left weed-free up to 20WAP with the highest yield of 4.8 t/ha obtained, however, leaving the plot weedy for the

first 4 WAP produced the highest yield of 4.9t/ha. Thereafter there was generally yield reduction. Yield reduction range between 16-37% under weed free regime as against 14-

77% under weed infested regime. However, Hausa potato yield tended to increase after maintaining a weed free plot up to 16 WAP because the crop is able to suppress weed

beyond this period as a result of closed canopy cover.



(ISTRC-AB)

139

Yield responses of sweetpotato (ipomoea batatas) and soyabean (glycine max)

intercrop to nitrogen levels in south eastern Nigeria.

Obasi C.P, I.I.M Nwankwo, T.C Madu National

Root Crop Research Institute, Umudike Nigeria

[email protected]

Abstract

A study was carried out during the 2006 and 2007 wet seasons in the low land humid forest zone of south-eastern Nigeria to investigate the effects of four nitrogen (N) levels

(0,40,80,120kg/ha ) on soybean and sweetpotato intercrop laid out in a 2 x 4 factorial in

RCBD. Sweetpotato variety used was Tis 87/0087 and that of soybean was TG X 184-4E. Result showed that in both years sole cropping differs significantly (P< 0.05) from intercrop.

Yield increased significantly as N application increases. The revenue in terms of gross monetary returns (using mean of the two years) in naira( ¦ ) achieved due to the combination

of the crops were highest in N application of 80kg and 120kg N per hectare (¦ 11,124,325 and ¦ 14,259,760 respectively). Therefore, 80kg N was recommended since there were no

significant differences between the yield in 80 and 120kg N, considering the high cost of

fertilizer which is not readily available to the farmers.



(ISTRC-AB)

140

Effects of wood ash, nitrogen and intra- row spacing on plant height, number of leaves and tuber yield of potato (solanum tuberosum l.) at Kuru Nigeria

G.L Daure 1, N.C Kuchinda2, I.U Abubakar2 and L.Aliyu2

Corresponding author: [email protected] 1National Root Crops Research Institute, Potato Programme, P.M.B 04 Kuru – Vom, Nigeria

2Department of Agronomy, Faculty of Agriculture / IAR Samaru, Zaria, Kaduna State, Nigeria

Abstract

Field experiments were conducted during the 2008 and 2009 wet seasons at the experimental farm of the National Root Crops Research Institute, Potato programme, Kuru, (Lat 090 44’

N and Long 080 44’E and with an elevation of 1,239.4m above sea level) in the Northern

Guinea Savanna ecological zone of Nigeria. The experiment was conducted to determine the effects of various rates of nitrogen (0, 60 and 120kg N/ha), wood ash (0, 2.5 and 5.0t/ha) and

intra – row spacing (20, 30 and 40cm) on the growth and yield of potato. A split plot design was used where the factorial combinations of N and intra- row spacing were assigned to the

main plots, while wood ash was assigned to sub plots. The treatments were replicated three times. The result revealed that application of 60 - 120kg N/ha and 2.5 - 5.0t/ha wood ash

enhanced crop growth and yield of potato VIZ: Plant height, number of leaves per plant and

total tuber yield respectively. With the exception of plant height in 2008, all the growth parameters increased with intra – row spacing from 20 – 40cm. The use of 30 or 40cm

spacing resulted in higher total tuber weight and yields compared to closer spacing of 20cm. Factor interaction of nitrogen and intra – row spacing was significant for; plant height, number

of leaves per plant, and total tuber yield.



(ISTRC-AB)

141

Control of weeds using herbicide on cassava crop

Frangoie Ngoie A1., Mahungu N.M1., Ndonda M1., Mukendi T1., Kilumba M2.

[email protected] 1International Institute of Tropical Agriculture, IITA/DRC ([email protected];

[email protected]; [email protected]) 2Institut National pour l’Etude et la Recherche Agronomiques ([email protected])

Abstract

Fight against weeds is one of the biggest problems facing producers. The most commonly used method, weeding with the hoe is expensive in certain situations where labor is scarce and especially with large farms. In such situations, weed control using herbicides is a better

alternative for lower costs and improved yields. This study was conducted during 2011/2012

season at 4 sites of low-altitude representing two agro-ecological zones (savanna and forest) of Democratic Republic of Congo. A factorial experiment involving three factors; weeds,

four varieties of cassava (branched and erect varieties) and glyphosate based herbicides were replicated three times. Weed control and cassava varieties were the main and secondary

factors respectively. Herbicide used was a non-selective and contact glyphosate-based herbicide. Compared to manual weeding, herbicide application before planting could be lower

or higher. However, at all locations, differences between herbicide application before planting

and manual weeding were not significant. At all locations, the highest yields were obtained with branching varieties; Mvuazi recorded 17 t/ha while Zizila an erect variety recorded 13t/

ha respectively. Net income obtained was higher by using herbicide in Kinshasa site with $ 490,7 compared to $ 317,85 at Mvuazi site. Use of glyphosate-based herbicides in cassava

crop may constitute a better alternative to weeding, especially at locations where species of weed could be easily managed by glyphosate-based products.








(ISTRC-AB)

142

Agronomic evaluation of new cassava (Manihot esculenta Crantz) clones with

colored flesh in an ecology of southern Côte d’Ivoire

N’zue Boni(11), Zohouri G. Pierre (12), Ebah-Djedji B. Catherine (13), Kouakou Amani

Michel(14), Paul Ilona(2) and Dibi Konan B.E.(15)

(11)[email protected], (12)[email protected], (13)[email protected], (14)[email protected], (15 )[email protected]

(11, 12, 13, 14, 15) Programme Plantes à Racines et Tubercules

CNRA, www.cnra .ci, Côte d’Ivoire (2 )p [email protected] (2) Country Manager of HarrvestPlus

Abstract

Cassava occupies, by volume, the second largest food crop after yam, with a production of2.45 million tons (FAO, 2011) in Côte d’Ivoire. It is both for subsistence and cash crops for

farmers in poor majority. By-products are multiple (attiéké, foutou, placali, toh, flour, starch, gari, etc.). The crop is consumed by almost all social strata and is marketed locally in the sub

region. However, most varieties are white fleshed and are therefore deficient in â-carotene (pro-vitamin A). Unfortunately, the consumption of white colored flesh cassava does not

complement the vitamin A deficiency in the population. To overcome these short comings, new cassava varieties with colored flesh were introduced from IITA and were assessed. An

evaluation trial of 24 varieties with colored flesh was conducted on an experimental station in

the south of Côte d’Ivoire. The two controls were TMS30572 reference for yield performance and Yacé for the dry matter content. After harvest and analyzing data, 10 genotypes, with

yields ranging between 27 t/ ha and 62t /ha and dry matter content between 30% and 43% were selected. Compared to controls, a gap of yield and dry matter content peaking at 195%

and 13% respectively was obtained. In addition, 6 varieties among the selected clones presented a flesh colored dark yellow or orange, which may reflect the presence of a high

content of â-carotene. Future evaluation trials will continue at stations and on-farm in order to propose the best genotypes for users.






http://www.cnra.ci/



(ISTRC-AB)

143

Lead and cadmium uptake characteristics of turmeric: effect of single and mixed

contamination of two benchmark soils of Southeastern Nigeria.

1*Nwokocha, C.C., 1Ano, A.O., 1Olojede, A.O. and 2Igwe, C.A.

1.National Root Crops Research Institute Umudike, PMB 7006 Umuahia Abia State Nigeria.

2. Soil Science Department University of Nigeria Nsukka, Enugu State Nigeria.

* [email protected]

Abstract

A completely randomized experimental design with five treatments levels (3 replicates each) was conducted in the greenhouse to determine the effect of single Pb (0, 50, 100, 150 and

200 mg/kg) and Cd (0, 1.5, 3.0, 4.5 and 6.0 mg/kg) and mixed treatments of Pb and Cd using two benchmark soils (Rhodic Kandiudult represented by Amakama soil and Aquic Haplustalf

represented by Ajata-Ibeku soil) on turmeric (Curcuma longa Linn) uptake and growth. Results showed that treatment had significant effect on biomass production. Phyto-toxicity

occurred on e” 100 mg/kg Pb and /or e” 3.0 mg/kg Cd in both soils. Total Pb uptake ranged from 0.264 – 3.303 mg/kg and total Cd from 0.119 – 0.822 mg/kg, suggesting that turmeric

may not be an extractor of Pb and Cd. Reduction in biomass production due to phyto-toxicity

was indicative that maximum extraction capacity had been attained. Co-presence of Pb and Cd significantly increased Cd uptake in both soils but antagonized Pb uptake in Ajata-Ibeku

soil, suggesting that Pb uptake due to interaction was soil specific. Pb and Cd accumulation in turmeric followed the order: rhizome > root > shoot. Nevertheless, uptake of Pb and Cd by

the rhizome was below recommended rhizome maximum limits of 10.7 and 3.0 mg/kg, respectively. Consumption of turmeric rhizome grown in Pb and Cd contaminated environment

do not pose any health risk given their low provisional tolerable weekly intake (PTWI) values of < 0.25 and < 0.08 mg/person/week for Pb and Cd, respectively. Monitoring heavy metals

in soils and edible plant parts should be regarded as a requirement for safe consumption of

crops grown in contaminated agricultural fields.

Key words: Turmeric rhizomes, Metals uptake, Rhodic Kandiudult, Aquic Haplustalf.



(ISTRC-AB)

144

Comparison of cassava yield variations from four-year continuous cultivation

under sole and mixed cropping systems in an ultisol of Eastern Nigeria

1Asadu, C.LA., A.G.O. Dixon2 and R. Okechukwu3

1Deparment of Soil Science, University of Nigeria, Nsukka, Nigeria 2Sierra Leone Agricultural Research Institute (SLARI)

3International Institute of Tropical Agriculture (IITA) Ibadan, Nigeria

Abstract Four cropping arrangements namely Sole Cassava (SC), Yam+ Cassava + Maize + P igeon Pea (Y+C+M+P), C+M+P and C+P mixtures were grown continuously for four years in an

ultisol brought into cultivation as a virgin forestland. The objective was to compare cassava yield variations as affected by residue management and zero external input considered as a

low input technology beneficial to low income farmers. All the crop residues especially the above ground vegetation (leaves from yam, cassava and pigeon pea and the entire for maize

except the cob) were incorporated into the soil as a sources of nutrients. The study showed that year-to-year cassava root mean yield was highest in C+M+P or C+P plots though the

differences were not significantly different. For the four years, the root yields ranged from

17.0 tha-1 obtained from C+M+P to H” 7.0 tha-1 also obtained from the same plot. The average root yield from root 1988-2000 showed that the highest (11.2 t ha-1) was obtained

from C+M + P and the least from Y+C+M+P even though the differences were also not significantly different. The difference in yields was not also significant in 2001 even though

the highest yield (9.5 t ha -1) was obtained from SC plots and the least from C+M+P plots. The differences in harvest index (HI) both in each year and for the four years were not

significantly different. The overall trends in results portrayed an indication that soil incorporation

of residue is sustainable especially with zero external input in the four cropping arrangements studied.

Key words: Cassava, zero external input, cropping arrangements, ultisol, Eastern Nigeria


(ISTRC-AB)

145

Research gaps in cassava production environment: a review

Asadu, C.L.A1.; S. Hauser2 and G.U. Nnaji1

1Department of Soil Science, University of Nigeria, Nsukka 2International Institute of Tropical Agriculture (IITA), Ibadan

Abstract

Cassava, (Manihot esculenta Crantz) is a crop plant of tropical lowlands between latitudes of 300 North and South. However, it is most wide spread near the equator between 150 North

and South. Most researches in cassava have been on many aspects inclding responses to soil especially on organic and mineral fertilizer trials, pest and disease management systems.

Variations in growth and yield under these conditions are well known. Yield drop from 30tha-

1 to 17tha-1 and 15tha-1 to 7tha-1 in continuous cultivation without application of fertilizer have been reported. Also, this review noted that researches in nutrient removed by cassava and

nutrient concentrations of different parts of cassava are well documented. Furthermore responses of cassava to tillage methods in different parts of the world have been reported.

Similarly, researches on water and light needs of cassava is well known. The ever increasing population especially in Africa has led to increases in the demand for cassava food, feed, fuel

and raw materials. This increase in demand will require increase in supply. This review

identified some gaps in cassava researches that will help improve its total world production and cassava farmer’s income; such gaps include; identification of some other constituents of

cassava that could make it more suitable for specific kinds of food, raw material for confectionery, pharmaceutical and other industries. Researches aimed at developing varieties

that can store for a longer period in the soil after harvest, before it is processed. Researches on various nutrient interactions are necessary to explain low yields in cassava. Site specific

trials are needed in areas mineral and organic fertilizer combinations for optimum cassava

production. Identification of some micro and macro organisms that could have symbiotic relationship with cassava under intercropping systems. Researches on irrigation scheduling

in irrigated cassava production and the economics of growing the crop under irrigation is needed.

Key words: cassava, research gaps, increased production


(ISTRC-AB)

146

Effet de précédents culturaux de Pachyrhizus erosus, de Mucuna pruriens,

d’arachide et de maïs sur la productivité du maïs au Centre-Bénin

Antoine BADOU15, Kouessi AÏHOU 1, Patrice ADÉGBOLA2, Pascal

FANDOHAN 3, Narcisse TAÏWO1, Basile ZANOU 1

[email protected] 1 Centre de Recherches Agricoles Centre (CRA-Centre), Institut National des Recherches

Agricoles du Bénin (INRAB), 01 BP 884 Recette principale, Cotonou, Bénin

² Programme d’Analyse de la Politique Agricole (PAPA), Institut National des Recherches

Agricoles du Bénin (INRAB), 01 BP 128 Porto-Novo, Bénin 3 Programme de Technologies Agricole et Alimentaire (PTAA), Institut National des Recherches

Agricoles du Bénin (INRAB) , 01 BP 128 Porto-Novo, Bénin

Résumé

La baisse de la fertilité des sols est l’une des contraintes majeures qui limitent la production agricole dans la région centrale du Bénin. L’objectif de ce travail est d’évaluer l’effet des

résidus de deux accessions de Pachyrhizus erosus (EC-533 et EC-KEW) sur la productivité du maïs en comparaison avec d’autres précédents culturaux tels que (Mucuna pruriens,

arachide et maïs). Pour ce faire, les expérimentations ont été conduites sur deux années suivant un dispositif expérimental en blocs de Fischer en quatre répétitions avec dix traitements.

Les essais ont été installés en station expérimentale à Gobé et en milieu paysan sous gestion

chercheur à Gbanlin. L’évaluation des biomasses aériennes des différents précédents culturaux ont montré des productions assez faibles. De même, les rendements en maïs grains obtenus

sur les différents précédents culturaux sont faibles. Toutefois, l’analyse de variance a montré une différence hautement significative entre les traitements sur les deux sites de production

(p=0,00). Le traitement maïs sur précédent maïs sans fumure minérale (MaF0) a donné le plus faible rendement moyen en maïs grains : 359,4 Kg/ha sur le site de Gobé et 39,1 Kg/ha

sur celui de Gbanlin. Par contre le rendement moyen en maïs grains le plus élevé a été obtenu sur chacun des sites avec le traitement maïs sur précédent Mucuna avec fumure

minérale (MuF1) : 1078,1 Kg/ha à Gobé et 677,1 Kg/ha à Gbanlin. Toutefois, les résultats

n’ont indiqué aucune différence statistiquement significative entre les effets du Mucuna et ceux du Pachyrhizus sur le rendement du maïs.

Mots clés: Légumineuse, fertilité du sol, productivité , Savè, Ouessè



(ISTRC-AB)

147

Evaluation of some newly released cassava varieties on growth performance

using two and four node stakes for stem production.

1 Njoku, S.C., 1Egesi, C.N 1Ano .A, and 2Ikeogu, U.N

1 National Root Crops Research Institute Umudike Nigeria; 2Michael Okpara University of Agriculture, Umudike

Email: [email protected].

Abstract

Cassava (Manihot esculenta Crantz) is the major source of carbohydrates in Sub-Saharan Africa and the fourth most important tropical crop worldwide. Cassava is a major staple and cash crop for millions of people in tropical Africa In Nigeria, cassava production is by far the

largest in the world and one third more than the production of Indonesia and Thailand. It is

fast assuming a commercial and industrial rather than subsistence value. The crop has low multiplication ratio which poses challenges in the efficient distribution of improved varieties

to farmers and other users due to insufficient planting materials. The study was carried out for two years 2008-2010 to evaluate the effect of five cassava varieties in direct planting of

two and four node stake for stem and root production yield as well as other agronomic attributes. Improved cassava varieties TMS 980505, TMS 980510, TMS 980581, TMS 972205,

NR 87184 collected from NRCRI Umudike and two farmer preferred varieties were used

for the study. They were planted in a I m x 0.25m planting distance with a plot size of 5 x 4 meters in a randomised complete block design with three replications. Parameters such as

percentage establishment, number of bundles, shoot weight (kg/ha), number of roots per plot and fresh root yield (FRY) were evaluated. Result showed that number of nodes per planting

stake had significant effect (P<0.001) on all cassava trait. Also different varieties used did not respond alike for all studied attributes and there was variation in the two cropping years.

The four node planting materials had better performance than the two nodes. Direct planting

of two and four node cassava holds a great potential for rapid cassava stem multiplication as well as appreciable root yield.The technique can be used in overcoming simultaneously the

shortage of planting materials and low yield in cassava.



(ISTRC-AB)

148

Influence of yam sett-weights on tuber yield in two cultivars of Dioscorea

rotundata

E.K. N’KPENU [email protected]; Y.D. SUNU

[email protected]

ITRA/CRA-SH, B.P. 88 Sotouboua, Togo

Abstract

Tuber sett-weights used by yam producers range from 800 to 1500 gin traditional cultivation system and requires a large quantity of material. The research has recommended sett from

200 to 500gto save material for consumption. Over the last twenty years, the climatic change

had affected yam cultural system due to the delay of rains, delaying planting dates hence resulting in degeneration of planting materials. Therefore, it is important to adjust tuber sett-

weights to the present weather. The objective of this trial was to identity yam tuber sett- weights which could allow for a reduction in the quantity of planting material and to produce

high tuber yield.Five tuber sett-weights (200, 400, 600, 800, 1000g) of two cultivars of Dioscorea rotundata (white guinea yam) He-abalou (earlier yam) and Kratsi (late yam)

were tested in the humid savannah zone at Kazaboua in Central Region of Togo in 2012. The

experimentwere laid out as a split plot in a Randomized Complete Block Design (RCBD). The main plots treatments were cultivars planted and the sub-plot treatments were sett-

weights. The results showed that for the two cultivars, sett-weights 400g and 600g produced respectively 16.29 tonnes/ha and 16.45tonnes/ha tuber yields which were statistically equivalent

to the yields ofsett-weights 800g (15.77tonnes/) and 1000g (18.20 tonnes/ha).The sett-weights 400g and 600g appear to meet the objective.





(ISTRC-AB)

149

Development of cost reducing weeding systems for cassava production in Nigeria

O.N. Eke-Okoro, N. J. Amanze, F. N. Nwakor, A. O. Akinpelu

and O. C. Eke-Okoro, J. Mbe and V. Ekpe National Root Crops Research Institute Umudike, P.M.B 7006 Umuahia

Abstract

The high cost in cassava production, precipitated investigation on possible agronomic intervention

to reduce cost of production to the barest minimum. In 2006/2007 and 2007/2008 cropping season, thirteen weeding systems were evaluated at the research farm of the National Root

Crops Research Institute, Umudike Nigeria. The result of this trial showed that there was marginal difference between three best weeding system .Application of pre-emergence

herbicide (PE) + 2 manual weedings at 8 and 12 WAP, manual weeding at 4, 8 and 12 WAP and manual weeding at 6 WAP + 2 under- brushings at 20 and 32 WAP) sustained cassava

fresh root yield of 25 – 27t/ha. There were no significant differences among the three systems. Net profit among the three best weeding systems followed the same trend.

Therefore, weeding at 6WA+s two under brushings at 20 and 32 WAP could be recommended

as an intersection cost reducing weeding system for cassava production in Nigeria.


(ISTRC-AB)

150

Differential responses of sweetpotato cultivars to fertilizer NPK in a high rainfall

area of Southwest Nigeria

V.O. Aduramigba-Modupe 1*, A.O. Aduramigba-Modupe 2, A.O. Adetayo1, S.O.

Olanipekun1and A.O. Denton1

1Institute of Agricultural Research and Training, Obafemi Awolowo University, Moor Plantation,

PMB 5029, Ibadan, Nigeria 2Department of Crop Protection and Environmental Biology, University of Ibadan,

Ibadan, Nigeria

*[email protected]

Abstract

The choice of appropriate fertilizer management is crucial for sustainable farming in tropical ecosystems. A field study in a high rainfall alfisol in Ikenne Southwestern Nigeria was conducted to evaluate the response of sweetpotato varieties to fertilizer NPK application.

The six varieties and two fertilizer NPK rates were arranged as a split plot in a randomized

complete block design, with three replications. Measurements showing significant response to treatment effects were vine length and root yield. The response was pronounced at 600kg/

ha which significantly produced higher root yields across varieties (yields ranged from 12.0 to 16.0 t/ha). The varieties showed significant foliage cover with fertilizer NPK amendments.

From the results, 600 NPK kg/ha fertilizer rate was sufficient for root production. Keywords: Alfisol, root yields, NPK fertilizer, sweetpotato.



(ISTRC-AB)

151

Chemical and integrated nutrient management options sustainable yam

production

S. A. Ennin1*, E. Owusu Danquah1 and P. P. Acheampong1

* [email protected]. 1 CSIR -Crops Research Institute, P.O. Box 3785, Kumasi, Ghana.

Abstract

Two main studies consisting of on-station trials at Fumesua (Forest) and Ejura (Forest-Savannah

transition) and on-farm verification on 12 farmers’ fields were conducted from 2009 to 2012

in Ghana. One on- station study was in a split-factorial combination design with two preceding systems (Pigeon pea and Yam) as main plot treatments and a factorial of poultry manure (0t/

ha, 3t/ha and 6t/ha) and chemical fertilizer (0, 15-15-20, and 30-30-40 kg ha-1 N-P 0 -K 0) as 2 5 2

subplot treatments. The second on-station study was split-plot with seedbed preparation (Ridge and Mound) and chemical fertilizer (0, 45-45-60, 60-60-60 and 60-60-80 kg ha-1 N- P 0 -K 0) as main and subplots respectively. The on-farm study was conducted in split plot

2 5 2

with seedbed (Ridge and Mound) and Chemical fertilizer (0, 45-45-60 kg ha-1 N-P 0 -K 0) as 2 5 2

main and sub-plots respectively on continuously cropped fields. The results of the on-station studies revealed significant (P< 0.05) interaction between preceding system, poultry manure

and chemical fertilizer on the tuber yields. When yam followed pigeonpea as a preceding crop, tuber yields were higher, and yields from 3t/ha poultry manure and 15-15-20 kg ha-1 N-

P 0 -K 0 was similar to yields when manure and chemical fertilizer were doubled to 6t/ha 2 5 2

and 30-30-40 kg ha-1 N-P 0 -K 0. It was also observed that tuber yields on 45-45-60 kg ha-

2 5 2 1 N-P 0 -K 0 plots were similar to the higher rate of 60-60-80 kg ha-1 N-P 0 -K 0 treated

2 5 2 2 5 2

plots on continuously cropped fields. The on-farm study revealed significant (P < 0.05) interactions between fertilizer (0; 45-45-60 kg ha-1 N-P 0 -K 0) and seedbed (Ridge and

2 5 2

Mound), with ridging having significantly (P < 0.05) higher tuber yields. Integrated nutrient management approach with preceding systems such as pigeonpea at 16,667 plants ha-1 and

3t poultry manure/ha would reduce the chemical fertilizer requirement to a third for sustainable yam production on continuously cropped fields.

Key words: Integration; legumes; climate change




(ISTRC-AB)

152

Post Vine Multiplication Evaluation of Microtuber Performance in Ghana

E. Otoo, R. Asiedu, T. Appiah-Danquah, H. Kikuno

Abstract

The vine multiplication techniques have been touted as a major breakthrough in seedyam generation. However, the microtubers generated have not been assessed for general

performance in the field. This study evaluated three yam varieties for general performance

after microtubers have been developed from its vine cuttings. Significant differences in variety performance were observed. The microtubers generally gave yields of 20-25 times the planting

materials. Microtubers planted gave reasonably sized ware yams.

Key words: Dioscorea, microtubers, seedyam, vine


(ISTRC-AB)

153

Analysis of the constraints to Seed Yam Production through the Yam Minisett

Technique in Benue State, Nigeria

Tokula M.H. Ekwe, K.C and Ikeorgu J.G.

National Root Crops Research Institute Umudike, Nigeria.

[email protected]

Abstract

The constraints to seed yam production through the minisett technique in Benue state North central Nigeria were studied; sixty yam farmers were purposively sampled from three local government areas (Otukpo, Obi and Ohimini) on the basis of their participation in the National

Specialized Food Security Programme (NSPFS). Data were collected with the aid of structured

questionnaire , and analyzed using descriptive statistics (frequency and percentage scores), and multiple regression analysis. Results showed that scarcity and high cost of fertilizers,

high weed incidence and high post-harvest losses, apathy of farmers to the size of the minisett and low knowledge of the component technologies constituted the major constraints to seed

yam production through the minisett technique. The regression results showed that age, marital status, labour availability and adoption were positive and significantly related to seed

yam production through the minisett technique. It was recommended that seed yam production

through the minisett technique can be improved through timely provision of fertilizer at affordable prices to farmers, use of herbicides and improved storage strategies should be

devised to minimize storage losses of yam.



(ISTRC-AB)

154

Progress in staking options in yam production for adaptation to climate change

S. A. Ennin1*, E. Owusu Danquah1, and P. P. Acheampong1

*[email protected]. 1 CSIR -Crops Research Institute, P.O. Box 3785, Kumasi-Ghana.

Abstract

Staking options studies were conducted on-station at Fumesua (Forest) and Ejura (Forest- Savannah Transition) and on-farm at Ejura, Hiawoanwu and Atebubu communities of Ghana

from 2011 to 2012. The on-station study was in a split-plot design with three yam varieties (Dente, Water Yam and TDR95/19177 line) and staking options (No staking, vertical staking

and horizontal staking with 50% number of vertical stakes) as main plots and subplots

respectively. The on-farm study was also in a split-plot design with staking options (farmers’ staking and horizontal staking with 50% number of farmers’ stakes) and seedbed (ridge and

mound) as main plots and sub plots respectively. Significant differences were found in staking options in Ejura where rainfall pattern was favorable but not in Fumesua. The horizontal

staking option with 50% less stakes gave similar yields (16.6t/ha) as vertical staking (17.1t/ ha). No staking resulted in significant (p< 0.05) yield reduction of 22.2% from the vertical

staking. TDR95/19177 gave the highest yield in Fumesua but was next to water yam in

Ejura where yields were generally higher. Though Dente had the lowest yields in both locations, economic analysis would determine the profitability of the varieties and the no

staking option. The staking options had similar effects on weed suppression, however variety significantly (p< 0.05) affected weed suppression with TDR95/19177 suppressing weeds

34% and 32% more than Dente and Water yam respectively. Results from the on-farm revealed a significant (p< 0.05) interaction between staking option and seedbed with ridged

and horizontal staking recording significantly (p< 0.05) higher tuber yield of 30%, 29% and

11% as compared with horizontal staking on mounds, farmers staking on mound and farmers staking on ridges respectively. These results suggest whiles effort should be made to breed

for varieties more suited for no staking option, a 50% reduction in number of stakes for yam production is possible with horizontal staking to reduce the deforestation associated with

staking in yam production.

Key words: 50% reduction in stakes, Yam production, Deforestation


(ISTRC-AB)

155

Appropriate farming practices resilience to climate change : Case of cassava on

non-incineration of a grassy fallow forest of Kisangani

A.M Ndonda1, N.M Mahungu, A.N Frangoie

1 International Institute of Tropical Agriculture (IITA), 4163, Avenue Haut-Congo, Kinshasa

Gombe, DRC

[email protected]

Abstract

Crop production has been affected by adverse effects of climate throughout the world since decades. This situation does not allow farmers to master appropriate agricultural calendar and therefore, it promotes reductions in crop yields. In Africa, 30% of these losses are

attributed to the effects of climate change hence the, need to develop coping mechanisms

especially for cassava which is the staple food crop of the Democratic Republic of Congo and occupies more than half of the spaces subculture. Agricultural practices currently in

vogue, do not protect the environment and in this study, methods of circumventing incineration which is the usual method of preparation of land in the forest, have been input to evaluate

their performance on the yield of cassava. After various analyzes, it was found that the labor performed on the grassy wasteland resulted in a significant increase in cassava production.

The yield increases of 62.5% were obtained when comparing plowing to non-incineration

and 44.4% when compared to the practice of complete burning. Several analyzes have revealed interactions between factors and observed as a calculation of the correlation between

soil properties and yields obtained by the modes of soil preparation was made from simple and multiple linear regressions. The calculation of the margin of cultivation practices helped

to identify the mechanical tillage as an alternative practice in the forest zone and is likely to generate higher profits.

Keywords: Climate change, resilience, plowing, burning, grassy wasteland



(ISTRC-AB)

156

Development and dissemination of yam vine multiplication techniques

E. Otoo, R. Asiedu, T. Appiah-Danquah, H. Kikuno

Abstract

Cost and availability of seedyam has been cited as major constraints in expansion of yam cultivation. The available multiplication techniques such as milking, minisetts, junking among

others are effective but inefficient (have low multiplication ratios). To enhance the multiplication

ratio of yams, vine multiplication techniques for seedyam multiplication was developed and disseminated to farmers and Agricultural Extension Agents. The technique is effective and

efficient means of generating seedyams. The efficiency however is variety dependent. The demonstrated high multiplication ratio of this technique must be extensively disseminated to

enhance production and productivity of yams.

Key words: Dioscorea, vine


(ISTRC-AB)

157

Determination of maturity dates of some cassava varieties in DRC

D.Ndombo1 ; N M Mahungu1; M Bidiaka1et M.Kaziama2

International Institute of Tropical agricultural, Kinshasa/RDC; 2 Institut National pour l’Etude

et la Recherche Agronomique

Abstract

During their development, cassava varieties are usually harvested 12 months after planting, while farmers do a staggered harvest, which may extend beyond 24 months. Two trials of

cassava varieties (white and yellow flesh) were installed at Kiyaka in Bandundu province to assess the behavior of the cassava varieties over a period of 8-18 months. Cassava was

harvested over a period of two months from the 8th month. Preliminary results for two trials

indicate that yields of tuberous roots for most of these varieties increased gradually up to 16 months after planting. Beyond that date, the yield decreases. The causes of this decline are

not yet clear, but there have been several cases due to diseases and pests such as brown streak, root rot and green mite. These enemies have in one way or another been involved in

the reduction in root yield beyond 18 months.

Keywords: Date, maturity, yields tuberous roots,


(ISTRC-AB)

158

Maximizing cassava (Manihot esculenta Crantz) stems system in Tropical Africa

M. O. Yomeni1, M.O. Akoroda2 and A.G.O. Dixon3

1 International Institute of Tropical Agriculture, Bukavu, DR Congo 2 Cocoa Research Institute of Nigeria

3 Sierra Leone Agricultural Research Institute

Abstract

Cassava (Manihot esculenta Crantz) is a very important crop economically as it is widely grown all over the world. It continues to be propagated vegetatively through stem cuttings. The number of commercial stakes obtained from a single mother plant in a year ranges from

3 to 30, depending upon growth habit, climate and agronomic practices. Effective propagation

schemes have not been included in the development of improved cassava production technology. Several trials were established from 2005 to 2009 in Southern Nigeriato assess

different methods of maximizing cassava stem system in tropical Africa. Five nationally recommended varieties were tested in three node cuttings (2, 3 and 4 nodes per stake)

combined with three plant spacing combinations (0.8 x 0.37 m; 0.8 x 0.5 m and 1 x 0.5 m) 13 plant spacing combinations by 3 types of fertilizers; and also using different portions of the

cassava. Each of the trials had four replicates. Results showed that narrow spacing give

higher plant population therefore higher stem yield. The following combinations: stake with 2 nodes cuttings with plant spacing of 0.8 x 0.375, stake with 3 nodes cuttings with plant

spacing 0.8 x 0.5 m and 4 nodes cuttings with 0.8 x 0.5 m gave the highest stem yield of 13, 12 and 14 stakes per plant respectively. Using fertilizers, there was 75.9 % increase in stem

yield due to fertilizer. From the different stem portions used (bottom, bottom-middle, middle- top and top), the bottom-middle, middle-top gave the highest stem yield of 12 stakes each per

plant. Comparison of one stem harvest at 12 months after planting (MAP) with two stem

harvest within 12 MAP (ratooning) at six months interval showed that 56,000 stakes of 25 cm length are obtained from the ratooning while 15,000 stakes are obtained for the one stem

harvest at 12 MAP. In conclusion a part from appropriate agronomic practices, the combination of narrow plant spacings, use of fertilizer, use of bottom-middle and middle top portion of the

stem and ratooning methods are good system to maximize stem production in Africa.

Key words: Maximizing, cassava, stem system.


(ISTRC-AB)

159

Growth and yield of taro under dryland as affected by fertilizer types and

irrigation

C. M. Tfwala and S.M. Dlamini

[email protected]

Ministry of Agriculture, Department o f Agricultural Research and Specialist Services,

P.O. Box 4, Malkerns, Swaziland

Abstract

Taro (Colocasia esculentus) is a herbaceous plant normally 0.5m to 2.5m tall. In Swaziland taro is grown in the Hhohho region for home consumption and for sale in the city markets and

along the roads. The crop is normally grown in the wetlands which are unfortunately degraded

at a very fast rate. Appropriate use of fertilizer for the crop has not been explored in the Swazi conditions. An experiment conducted at Malkerns Research Station, Swaziland during

2010/11 and 2011/12 cropping seasons sought to explore the growth of taro on dryland with supplementary irrigation and evaluate the potential use of different fertilizer types for taro

growing. The experiment included four irrigation levels from rainfed (IR0) to well watered conditions (IR3) and three fertilizertypes; kraal manure (10 tons/ha), poultry manure (10

tons/ha) and N:P:K (2:3:2) (22)) (300 kg/ha). Irrigation level IR3 and IR2 produced statistically

equal yields and number of tubers and significantly higher (P<0.01) than the lowest irrigation levels (IR1) and the rainfed crop (IR0). The different fertilizers produced statistically similar

tuber yields and tuber counts. It was then concluded that supplementary irrigation is necessary when taro is grown on dryland using any of the three types of fertilizer and their application

rates. Further investigation, especially in the high yield where the crop is mainly grown was recommended.



(ISTRC-AB)

160

Organic ginger production in an ultisol in southeastern Nigeria

Ebeniro, C. N. and *Amadi, C. O.

[email protected]; *[email protected]

National Root Crops Research Institute Umudike, P. M. B. 7006, Umuahia, Abia State.

Abstact

The negative effects of inorganic fertilizer on food, health and environment have been widely documented. These have led to a renewed interest in organic farming as an environmentally friendly alternative for producing healthier food for human consumption. In 2011 cropping

season a trial was conducted in an ultisol at National Root Crops Research Institute’s field in

SE Nigeria to determine the effect of poultry manure and palm bunch ash on the field performance of ginger (Zingiber officinale). The design was a randomized complete block

design (RCBD) in a factorial arrangement with three replications. The treatments comprised four levels of poultry manure (0, 3, 6 and 9 t/ha) and four rates of palm bunch ash (0, 3, 6 and

9 t/ha) with a variety of ginger (UG1). Application of poultry manure and palm bunch ash significantly (P<0.05) increased tiller numbers and plant height at three and four months

after planting but had no significant effect on number of leaves produced. Poultry manure

and palm bunch applied at the rate of 6 t/ha resulted in a significant increase in rhizome yield at harvest.

Keywords: Organic manure, ginger, growth, yield.





(ISTRC-AB)

161

1 2

1 2

2 2

2 2

1

2 1

2

3

P K 5

Mineral fertilization of Pachyrhizus erosus (L.) ¶Urban cultivated on degraded

Oxisol in Southern Benin

M. R. Aguégué 1A. Adjanohoun 16, P. Y. Adegbola2, K. A. Djinadou-Igué 3, O.

D.Koudandé4, P. Fandohan 5 et G. A. Mensah 6

1 Centre de Recherches Agricoles Sud-Bénin de Niaouli, Institut National des Recherches

Agricoles du Bénin, 01 BP 884 Recette principale, Cotonou, Bénin 2 Programme d’Analyse de la Politique Agricole (PAPA), Centre de Recherches Agricoles

d’Agonkanmey, Institut National des Recherches Agricoles du Bénin (INRAB), 01 BP 128

Porto-Novo 3 Institut National des Recherches Agricoles du Bénin (INRAB), 01 BP 884 Recette principale,

Cotonou, Bénin. 4 Laboratoire des Recherches Zootechnique, Vétérinaire et Halieutique (LRZVH), Centre de

Recherches Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du Bénin

(INRAB), 01 BP 884 Recette principale, Cotonou, Bénin 5 Programme Technologie Agricole et Alimentaire, Centre de Recherches Agricoles


Porto-Novo, Bénin 6 Centre de Recherches Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin 7 E-mail address : [email protected]

Abstract

The objective of the study was to evaluate the effect of mineral fertilizer on the productivity of Pachyrhizus erosus cultivated on degraded Oxisol in Southern Benin. The experimental

design was a Split plot with three factors which are two varieties (V = EC.-533 and V =

EC.-KEW); three densities of sowing (D = 62.500 plants/ha, D = 31.250 plants/ha and D

= 15.625 plants/ha) and three mineral fertilizer (F = N P K ; F = N P K and F = N 1 0 0 0 2 30 40 60 3 60

80 120

with the figures indicating the quantities in kg/ha N, of P O and K O The weights of the roots, seeds and the dry biomass for the harvested area were determined. Roots

yields of 8.66 t/ha and 8.0 t/ha were obtained for varieties EC.-KEW and EC.-533 respectively at fertilizer levels F and plant density D . Roots yields of 4.62 t/ha and 2.13 t/ha were

obtained for varieties EC-KEW and EC-533 respectively at plant density D and fertilizer

level F1 (control) Plants that received fertilizer level F at density D presented the greatest

average seed yields, of 5.57 t/ha for variety EC.-KEW and 6.73 t/ha for variety EC-533. Results of the study showed that fertilizer level F increased root yield by 4.04 t/ha for EC-

KEW and 5.87 t/ha for EC-533 when fertilizer level F at density D is compared with plant

density D 2

and fertilizer level F (control). Fertilizer level F 2

opens a prospect for productivity 1 1 2

of Pachyrhizus erosus cultivated on degraded Oxisol.

Keywords: Tuberous, nitrogen, phosphorus, potassium, productivity, INRAB



(ISTRC-AB)

162

Effects of climatic and soil variability on sprouting ability, disease response and

yield of 30 cassava genotypes in 3 different agro-ecological zones

O.O. Etukudo,1,2, B. Maziya – Dixon 1 and L.A. Babatola2

1International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria 2 Department of Agronomy, University of Ibadan, Ibadan, Nigeria.


Presenting author: [email protected]

Abstract

Multilocational trials were conducted for two cropping seasons (2007/08 and 2008/09) in three agro – ecological zones (Ibadan, Mokwa, Zaira) in Nigeria to evaluate the response of 30 cassava genotypes to variability in agroecology. The aim was to identify the best cassava

genotypes with wide and specific adaptation for high fresh and dry storage root yield. The

study was conducted in a randomized complete block design with four replications. The data collected were subjected to analysis of variance using the general linear model (GLM)

procedure in SAS. Mean separation was done by Fisher’s protected least significant difference (LSD) test at 0.05 probability level. Results obtained from the study showed that soils of the

three locations were acidic, Ibadan had the highest rainfall distribution; cassava genotypes performed differently across and within locations for all the traits evaluated. Growth and

productivity of cassava was greatest at Mokwa compared to the other locations. The same

location showed the highest tuberous root dry weight followed by Ibadan location during both cropping season. Genotype 91934 is highly susceptible to cassava mosaic disease (CMD) as

it recorded the highest CMD severity across the three locations. The highest yielder for the three locations were stable for the two cropping season. The study concluded that the

genotypes 01/0040 and 95/0289 are high yielding and best genotypes for Ibadan, 98/0581 and 91/02324 for Mokwa while 01/0034 and 91/02324 for Zaria.




(ISTRC-AB)

163

Delivering the potential of potato in Mozambique: Challenges, opportunities and

strategies

1Charles Lung’aho, 2Martinho Carolino and 3Elmar Schulte-Geldermann

1International Potato Centre (CIP) SSA, C/0 SEMOC P.O. Box 75 Chimoio, Mozambique;

[email protected] 2IIAM- Centro Zonal Noroeste, Programa de Investigacao de Batata, Cx. Postal 238, Lichinga,

Niassa, Mozambique; [email protected] 3International Potato Centre (CIP) SSA, P.O. Box 25171-00603, Nairobi, Kenya; e.schulte-

[email protected]

[email protected]

Abstract

Mozambique has not fully harnessed its potential to produce and possibly export potato and

potato products. The country has vast amounts fertile lands with favourable conditions for growing potatoes-good soils and climate, and water resources. Constraints to realizing the

potential of the crop include poorly functioning potato value chains characterized by weak linkages with poor integration of value chain actors, poor seed systems, pests and diseases,

limited access to favourable capital, low levels of commercialization, poor infrastructure and

a weak private sector. A rising population and increased urbanization coupled with a growing fast food sector and a rapidly growing economy present excellent opportunities in seed potato

production, processing potatoes, consumption potatoes, packaging industries, transportation, agro inputs, and machinery and equipment amongst others. Concerted efforts by both public

and private sectors in strengthening the seed, ware and processing potato value chains could see the country becoming a major potato producer in the Southern African region in next few

years. Key issues that must be addressed for the potential to be unleashed include enhancing

the capacity for potato research and development; availing appropriate financing mechanisms; stimulating enterprise development; enhancing skills development; and creation of effective

mechanisms for the on-the-ground implementation of investments.

Key words: Constraints, Mozambique, opportunities, potato value chains, potential






(ISTRC-AB)

164

Yield and Micronutrient uptake of white yam (Dioscorearotundata L. Poir) as

influence by organomineral fertilizer ammendment on an alfisol in Ibadan South

western Nigeria

Lawal O.I.1, G.O. Adeoye 2, R. Asiedu,3 Ojeniyi, S.O.4 Atayese. M.O.1 and A.O.

Olaiya1

1. Department of plant physiology and crop production, Federal University of Agriculture,

Abeokuta, Nigeria 2. Department ofAgronomy, University of Ibadan.3. International Institute

ofTropicalAgriculture, Ibadan. 4. Federal University of Technology Akure

*Coresponding author: [email protected], [email protected],

[email protected] (+2347033802750, +2347082898159

Abstract

Fertilizer use for increased and sustainable yam production in the country is grossly inadequate and inefficient. Most research focused on the macronutrients in crop production, forgeting the importance of micronutients in plant nutrition. Field trials were conducted in 2004 and

2005 wet seasons, at the International Institute of Tropical Agriculture Ibadan Research

Farm to determine the influenceof organo-mineral fertilizer on some Micronutrient uptake of white yam in an organic-based production system. Four cultivars of white yam: “Adaka”,

“Amula” , “Danacha” and “Omiefun” were each subjected to 10 fertilizer treatments comprising sole Organic fertilizer (OF), mineral (NPK 12-12-12) fertilizers combinations of

the two (organo-mineral) and control, 2.5, and 5.0 t/ha OF; 0.15, 0.3 and 0.45 t/ha /ha NPK; 1.75 t/ha OF+0.15 t/ha kg/ha NPK; 2.5 t/ha OF+0.15 t /ha NPK; 2.5 t/ha OF+0.3 t/ha /ha

NPK and 5.0 t/ha OF+0.3 t/ha /ha NPK. The trials was conducted at Ibadan

(OxicKandiustalf), Southwest Nigeria. The experiment was a split-plot in randomized complete block design with four replicates. White yam cultivars and fertilizer rates were main and sub-

plot treatments, respectively. Tuber yield, Zn, Cu and cl uptake were assessed. Data obtained over two years were analyzed using analyses of variance; means were separated using

SED. “Amula” had the highest tuber yield of 10.7 and 22.1 t/ha in 2004 and 2005 respectively. Four fertilizer treatments (5.0 t/ha OF, 0.45 t/ha NPK, 2.5 t/ha OF+0.3 t/ha NPK, 5.0 t/ha

OF+0.3 t/ha NPK) significantly (P < 0.05) improved the growth and yield of white yam

compared to the control. Fertilizer treatment at 5.0 t/ha OF + 0.15 t /ha NPK produced the highest tuber yield of 16.0 t/ha in 2004 and 20.4 t/ha in 2005. They were significantly (P<0.05)

higher than the control plots in the two years. Similarly, the same fertilizer treatment had the highest Zn, Cu and Cl uptake for both years. There wereZn, Cu and Cl uptakes of 5.8, 7.2

and 6.3 g/plant respectively in 2005 and were significantly (P< 0.05) higher than the control. Fertilizer treatment at 5.0 t/ha OF+0.3 t /ha NPK was the best with reference to tuber yield

and nutrient uptake. “Amula” had the highest tuber yield during both years of study.

Key words: Dioscorearotundata, Fertilizers, Soil type, Tuber yield, micronutrient uptake.






(ISTRC-AB)

165

Varietal Response of Sweet potato (Ipomoea batatas) L Lam) to Fertilizer

Regimes in Different Agro ecologies in Nigeria

Onunka N.A Tokula M.H. Nwankwo M .I .I Ehisianya C. N.

National Root Crops Research Institute Umudike Km 8 Umuahia Ikotekpene Road Abia State

aonunka @yahoo.com.

Abstract

This experiment was carried out at the research stations of National Root Crops Research Institute Umudike and its out station Otobi during the 2012 cropping season. The aim of the study was to identify the response of two sweet potato varieties (white fleshed and orange

fleshed) to four fertilizer regimes under two agro ecologies. This was with a view to improving

their edible root yield and general performance due to climatic variations in the different ecologies considering the importance of the crop industrially and in the dietary and health

system of the people. The two agro ecologies were rain forest and Guinea Savannah. Treatments were arranged in a randomized complete block design. The eight treatments

were replicated three times in each location. Edible roots and root numbers were used to evaluate the performance of the two varieties. Results showed that location, variety and

location, and variety by fertilizer interactions were very highly significant (p<0.001) in the

parameters evaluated. The white fleshed out yielded the orange fleshed in both rain forest and Guinea Savannah at a fertilizer rate of 400 kg/ha . This calls for the need for ecological

adaptive trials to determine the different nutrient regime and recommendations for different varieties in different ecologies to obtain their maximum performance in each

ecology.

Key words: Sweetpotato varieties, fertilizer regimes, Agro -ecozones

mailto:@yahoo.com


(ISTRC-AB)

166

Response of four sweetpotato cultivars to water stress

R. Laurie, S. Laurie & CP du Plooy

Agricultural Research Council-Roodeplaat Vegetable and Ornamental Research Institute,

Agricultural Research Council, Private X293, Pretoria, 0001, South Africa, [email protected]

Abstract

Sweetpotato is an important staple crop and popular in South Africa as a food security crop. Drought tolerance of a crop in South Africa is of importance due to general semi-arid growing

conditions. Four orange fleshed sweetpotato cultivars (Ipomoea batatas (L.) Lam) were planted in a rainout shelter and subjected to three (100%, 60% and 30%) irrigation treatments.

A number of physiological measurements and biochemical analyses were conducted on the leaves and the plant canopy twice during the growth period of the plants. Roots were harvested

at the end of the trial and yield was determined. The Water stress had a severe impact on the performance of the crops and the cultivars showed a poor adaptation to water stress. Total

root yield was severely affected as a result of inhibited metabolism. Stomatal conductance values showed a large decline due to water scarcity. Leaf area index values also dropped

considerably. Interestingly, stem length continued to increase despite the water stress.

Antioxidant activity (peroxidase, superoxide dismutase) was determined in the harvested leaves of the plants. Peroxidase activity was found to stabilize and even increased as the

water stress prolonged. Superoxide dismutase activity also increased as the water stress prolonged, which indicate drought tolerance, although this was not detected in all of the

cultivars. The results demonstrated a large set of parallel changes in the morphological, physiological and biochemical processes when the varieties were exposed to drought stress

and these affected plant growth.



(ISTRC-AB)

167

Water yam (Dioscorea alata l.) microsett responses to plant density and mulching

in South Eastern Nigeria

Okpara, D.A.1, Ikoro A.I.2 and Ojikpong, T.O 3

College of Crop and Soil Sciences, Michael Okpara University of Agriculture,8

National Root Crops Research Institute (NRCRI)9

Umudike, Umuahia, Abia State, Nigeria

Department of Agronomy, Cross River University of Technology, Cross River State, Nigeria10

Abstract

Field experiments were used to study the response of water yam microsetts to plant density and organic mulch types in Umudike, south eastern Nigeria. The experiment was laid out as

5x4 factorial in a randomised compete block design (RCBD) with three replications. Treatments

consisted of five plant densities (33333, 40000, 50,000, 66666 and 100000 plants/ha) and four mulch types (dry grass, rice husk, wood shavings and no mulch). Tuber yield increased

significantly with increasing microsett plant density up to 100000 plants/ha. With an average yield of 43.5t/ha, the highest plant density of 100000 plants/ha increased tuber yield over

those at 66666, 50000, 40000 and 33333 plants/ha by 38%, 98%, 127% and 116%, respectively. Mulching did not significantly affect tuber yield but mulching with rice husk or wood shavings

increased soil potassium than mulching with dry grass.


(ISTRC-AB)

168

Evaluation of growth and yield response of sweetpotato (ipomea batatas l.) to

different rates of poultry manure in Abeokuta Southwestern Nigeria

Atayese Muftau Olaoye,1 Lawal, Omoniyi Isiaq1*, Afuape Solomon4, Sakariyawo

Olalekan Sulaiman1 , Olaiya Abideen1, Fetuga, Ganiyat Olayinka3 and Idowu

Taiwo Hazanat4

1Dept.of Plant Physiology and Crop Production, 2 Dept. of Soil Science and Land Management, 3Dept. of Food Science Technology, Federal University of Agriculture, Alabata Road, Abeokuta,

Nigeria. 4Sweetpotato Program, National Root Crop Research Institute,

Umudike Abia state, Nigeria.

* [email protected], [email protected]

Abstract

Field experiments were conducted at the Federal University of Agriculture Abeokuta, Nigeria during 2010 and 2011 cropping season to determine the optimum rate of composted poultry

manure and NPK 15-15-15 on growth and tuber yield of sweetpotato. Healthy vines (25cm

length) of three cultivars of sweetpotato cv. TIS 87/0087, Shaba and TIS86/0356 were planted at 0.5m distance on ridges spaced 0.75m apart. Four weeks after planting, composted poultry

manure (CPM) were applied at 0, 2.5, 5.0, 7.5 and 10t/ha and 400kg/ha NPK 15:15:15. The treatments were arranged factorially in Split-plot experimental design with four replicates.

Data on vine length, number of leaves, number of branches, leaf area index and weight of tubers were collected. The sweetpotato plants grown 10.0t/ha of compost produced

significantly (p<0.05) longer vines (341.3, 352.5cm), more leaves (524.9, 572.4), more branches

(25.4, 23.6) and higher tuber weight (9.9, 10.7 t/ha) for the two years respectively. These values were significantly (P<0.05) higher than those obtained from sweetpotato grown without

fertilizer (control) and those that received other fertilizer treatments except 7.5t/ha. Sweetpotato TIS 87/0087 treated with 10.0t/ha CPM had the highest tuber weight values of

10.9 and 10.4 t/ha for 2010 and 2011 respectively, showing significant (p< 0.05) differences as compared to the yields obtained in cultivars that received other fertilizer treatments except

those grown with 7.5 t/ha. The least tuber yield value of 8.7 and 3.6 t/ha for 2010 and 2011

respectively, was obtained in ‘shaba’ with no fertilizer treatment (control). Since tubers weight is a function of growth parameters, CPM at 7.5 t/ha in combination with the three cultivars

was therefore recommended for adoption in this study.

Keywords: Growth, Yield, Poultry manure, Sweetpotato





(ISTRC-AB)

169

Effects of Organic and Mineral Fertilizers on total Antioxidant, polyphenolic and

carotenoid contents of Orange fleshed sweetpotato tubers

Moumouni Koala1, Adama Hema*1, Koussao Some 2, Eloi Pale 1, Abdoulaye

Sereme 3, Jerome Belem2, Mouhoussine Nacro1

1 Laboratoire de Chimie Organique et de Physique Appliquees, Departement de Chimie , UFR-

SEA, Universite de Ouagadougou 03 BP 7021 Ouagadougou 03, Burkina Faso 2 CNRST/INERA, Departement Productions Vegetales, 03 BP 7047 Ouagadougou 03

Burkina Faso 3CNRST/IRSAT, Departement des substances naturelles, 03 BP 7047 Ouagadougou 03

Burkina Faso

* [email protected]

Abstract

A field study was conducted to determine the effect of organic and mineral-based fertilizers on phytochemical contents in the tubers of an orange fleshed sweetpotato variety (TIB-

440060). Treatments were arranged in a split plot design with three replicates. Tubers harvested have been studied for their total antioxidant contents (TAC), total polyphenolic contents

(TPC) and total carotenoid contents (TCC) using Ferric Reducing Antioxidant Power (FRAP), Folin-Ciocalteu reagent (FCR) and a method described by McMurry respectively. Organic

fertilizer had a positive effect on the production of antioxidants, polyphenols and carotenoids whose contents increased significantly (P < 0.001) with the quantities of organic fertilizer.

Increases about 19.61%, 34.41% and 12.82% due to annual (F1) inputs and increases about

15.94% and 15.46% and 12.17% respectively in total antioxidant, polyphenolic and carotenoid contents when these inputs of organic fertilizer are conducted biennially (F2). The effect of

different doses of mineral fertilizers indicated significant changes (P < 0.001) in accumulated antioxidant, polyphenolic and total carotenoids contents of TIB-440060 OFSP tubers. Total

Antioxidant, polyphenolic and carotenoid contents of TIB-440060 varied significantly (P < 0.001) with the combination of organo-mineral fertilization used. Combinations using a minimal

doses of 15 kg/ha of nitrogen, 30 kg/ha phosphorus and 45 kg/ha of potassium associated with an annual or biennial contribution of 20 t/ha of organic fertilizer gave the highest total

antioxidant, polyphenolic and carotenoid concentrations.

Key words: OFSP extracts, phytochemical contents, polyphenols, antioxidants,

carotenoids, organic fertilizer, mineral fertilizers, FRAP, FCR



(ISTRC-AB)

170

Effects of Maize intercrop at varied densities on yields and â-carotene content of

orange fleshed sweetpotato

Asiimwe A.1 Tabu I.M.1, Lemaga B.2*11, Tumwegamire S.2†12

1 Department of Crops Horticulture and Soils, Faculty of Agriculture, Egerton University

P.O Box 536, Njoro Kenya 2 International Potato Center (CIP), P.O. Box 22274, Kampala, Uganda

(asiimwealex08@yahoomail .com)

Abstract

Even when orange-fleshed sweetpotato and quality protein maize have clearly been demonstrated to respectively combat vitamin A and protein malnutrition, small landholdings by farmers further limit their productivity in rural Africa. Recommendations on intercropping

systems and appropriate plant density may help farmers to utilize the two crops to improve

household nutrition and food security. This study was undertaken to determine the effect of maize population in a sweetpotato-maize intercrop on crop productivity and â-carotene content

in sweetpotato roots. OFSP varieties Ejumula and Naspot 9 were intercropped with maize variety, Longe 5, at three plant densities, 41,666, 55,555 and 88,888 plants ha-1, at Ngeta

research station in Uganda in 2011 for two seasons. While 55,555 plants of each OFSP varieties were used for both sole and intercrop plots, the sole maize plot was 44,444 plants

ha-1. Maize and sweetpotato were harvested at 120 and 135 days after planting, respectively.

Data on grain yield for maize and root yield, total biomass, root dry matter and â-carotene content for sweetpotato were collected. Land Equivalent Ratio (LER) was used to measure

productivity in the intercrops. Intercropping significantly (P<0.05) reduced marketable sweetpotato root numbers and yields. Â-carotene content in sweetpotato roots was significantly

(P<0.05) reduced at high maize density probably due to shading. Naspot 9 yielded higher than Ejumula. The LER shows that intercrop densities 1 (sweetpotato55,555, maize 41,666

plants ha-1) and 2 (sweetpotato 55,555, maize 55,555 plants ha-1) consistently had ratios

above 1 and are recommended for sweetpotato-maize intercropping.



(ISTRC-AB)

171

Best time of supplemental mulch application for turmeric production in a

Rainforest Agro-Ecology of Nigeria

Olojede, A.O., Nwokocha, C.C., Akinpelu, A.O., Obasi, C.P and Ikeorgu F.


PMB 7006, Umuahia-Abia state Nigeria.

[email protected], [email protected].

Abstract

A field experiment was conducted in the research farm of the National Root Crops Research

Institute, Umudike in 2011 and 2012 cropping seasons, to investigate the necessity and best time of supplemental mulch application in turmeric (Curcuma longa Linn) production under

Umudike conditions. The experiment was laid out in a randomized complete block design (RCBD) with 4 replicates. Treatments comprised: 6 periods of supplemental mulch application,

control (once at planting), 2, 3, 4, 5 and 6 months after planting (MAP). Planting was done on raised beds measuring 3 m x 3 m using a plant spacing of 50 cm x 30 cm. All plots received

8t/ha of poultry manure at planting supplemented with 60 kg N/ha, 13 kg P/ha and 25 kg K/

ha applied 2MAP. Straw of Elephant grass (Panicum maximum) was applied as mulch treatment at the rate of 12 t/ha generally at planting and additional mulch application was

carried out at specified months after planting. The experiment was harvested at 7 MAP with necessary yield data collected for analysis. Combined analysis of the two years results showed

that supplemental mulch application significantly affected mother rhizome and total rhizome yields. Supplemental mulch application at 2 months after initial application resulted in the

highest mother rhizome yield (8.46 t/ha) and total rhizome yield (30.32 t/ha). It was concluded

that supplemental mulch application is necessary for Turmeric production and should be carried out at 2 MAP after initial mulch application for optimum rhizome yield.

Key words: Turmeric, rainforest agro-ecology, mulch application, Umudike.






(ISTRC-AB)

172

Evaluation of some improved and local yam genotypes for yield and yield

components in northern Ghana

J. Adjebeng-Danquah1*, S.K. Asante 1, K. Acheremu1, A. Nimo-Wiredu1, F. Kusi1

1CSIR-Savanna Agricultural Research Institute

* [email protected]

Abstract

Trials were conducted for two growing seasons (2011 and 2012) at Lantinkpa in the East Gonja district to evaluate ten improved yam genotypes obtained from the International Institute of Tropical Agriculture for high yield, resistance to pests and diseases and to assess their

general adaptability to the local growing conditions of the northern Ghana. The ten yam

genotypes include; 95/19156, 95/18949, 95/18922, 95/01942, 96/02025, 96/02610, 95/19158, 95/18544, 96/00594 and 95/19177. The improved genotypes together with four local farmer

preferred varieties (Puna, Laribako, Asana and Dente) were arranged in a randomised complete block design with three replications. Each plot consisted of 20 mounds. Staking

was done at two months after planting using stakes measuring 1.5m high. Weeding was done as and when necessary. Data collected include germination/establishment, pests and diseases

attack/damage. Harvesting was done at six and eight months after planting (MAP). At harvest

data were collected on tuber yield (t/ha), mean tuber weight (g), dry matter content as well as food quality assessment. The results indicated higher percentage establishment for the

improved genotypes compared with the local checks. Though all the genotypes were found to be susceptible to anthrachnose, virus infection and tuber rot, the virus infection was

comparatively higher on the local genotypes than the improved genotypes. The genotypes also showed differential response to yam pests such as millipedes, mealybugs, scale insects,

nematodes and yam leaf beetles. Laribako was found to be most susceptible to these attacks.

Tuber yield also differed significantly (P<0.05) among the genotypes with the improved genotypes giving higher yield than the local. The highest tuber yield obtained at six months

was 15.38 t/ha which was obtained from genotype 96/00594. This yield increased only marginally (16.53 t/ha) when harvesting was done at eight MAP indicating early maturity.

Genotypes 96/02610, 95/19158, 95/19156 all gave tuber yields that were above the local checks except genotype Asana at eight MAP. All the local genotypes were early bulking

compared to the improved ones. Based on appearance, texture, flavour and taste, both the

farmers and consumers selected genotypes 96/00594, 95/18949, 95/01942, 95/19158 and 95/ 18544. In terms of poundability, genotypes 96/00594 and 95/01942 were the most preferred.

The results from this trial identified some promising genotypes which can be taken through multilocational trials to assess their stability and possible release to farmers to boost yam

production in northern Ghana and alleviate poverty.

Key words: improved genotypes, adaptability, farmer preferred varieties, quality assessment



(ISTRC-AB)

173

Assessment of performance and farmers’ preference varieties through

participatory variety selection calls for doubling breeding effort in Zambia

Ntawuruhunga P1., Chiona M2., Manda N3.,Korie S4 and Njobvu J2

[email protected] 1IITA-Malawi, PO Box 30258, Lilongwe, Malawi

2ZARI-Mansa, Box 710129, Mansa, Zambia 3 IITA-Zambia, 32 Poplar Road,Avondale, Lusaka

4IITA-Nigeria, PMB 5320, Ibadan, Nigeria

Abstract

The Mitigation Cassava Diseases Threats for Improving Cassava Production project in Zambia is using the participatory variety selection approach to understand why adoptions lowand

identify best preferred improved varieties forpromotion. Five improved varieties were evaluated

under farmers’ field conditions in 6 districts of Luapula, North and Eastern Provinces where each farmer was usedas replicateand the farmers’ local cultivars used as checks or

unreplicated lines. This was a multi-site trial.The results showed that the districts of Mambwe and Petauke in Eastern Province had significantly (p<0.001) better yields (19.7 and 18.1t/ha,

respectively) than the districts of Mansa (9.22t/h), Kasama (9.01t/ha) and Luwungu (7.54t/ ha) in the Luapulaand North Provinces respectively and traditionally known as cassava growing

regions. It was found that farmers performed significantly (p<0.001) differently in evaluating

improved supplied varieties when compared without the local checks,whereas when compared with the local checksthe results indicated that some local cultivars outperformed the improved

supplied.Nevertheless the improved Mweru, Kampolongo and Nalumino were the overall best yielding and resistant to disease. However, the culinary results revealedthat most of the

local cultivars were still preferable by farmers compared to improved varieties though they were susceptible to mosaic disease. Both principal component analysis and correlation analysis

confirmed that preferred varieties were mealy with good taste. Nalumino was the only

improved variety averagely preferred by farmers. The present results are hence challenging breeders to double efforts in identifying and selecting high yielding resistant varieties but

most importantly farmers’acceptable varieties in order to enhance adoption and boost production in the country.

Key words: Improved varieties, local cultivar, preferred varieties, adoption



(ISTRC-AB)

174

Soil physico-chemical properties and rainfall relationship with cassava growth and

yield in Nsukka Southeastern Nigeria

Godwin Uche Nnaji

Department of Soil Science, University of Nigeria Nsukka

Abstract

Identification of soil nutrients that has significant influence on cassava yield in a given area will determine the type and quantity of fertilizer to be applied for crop improvement and soil

conservation. At Nsukka, Southeastern Nigeria, a study was carried out to determine the

contributions of some soil physical and chemical properties as well as rainfall to the performance of cassava. Data used for the study was collected from a three years field

experiment. It was a randomized complete block design experiment with six treatments and four replications. Cassava varieties planted were TMS 30572 and TMS 30555. The treatments

were composed of Rice mill waste (RH), poultry manure (PM) and NPK Mg mineral fertilizer. The organic materials were applied at rates of 10t ha-1 only either solely or in an equal

combination of both (5 t ha-1 RH + 5 t ha-1 PM). Mineral fertilizer was also applied solely

(0.48 t ha-1) and in combination with 10 t ha-1 rice mill waste. Result showed that bulk density, porosity, mean weight diameter total N, available P, exchangeable bases – Na, K, Mg and Ca

had positive correlation with cassava growth and yield. Relationships between cassava fresh tuberous root yield (Y) were significant (P< 0.05) only for P, Ca and Mg with these

regression equations- Y=32.30 + 6.30X, Y= 6.8 + 8.43X and 7.77+11.46X respectively. The root tuberous yield has positive correlation with rainfall amount and number of rainfall days.

Based on this study, P, Ca, and Mg fertilizers are recommended for cassava farmers in

Nsukka area. Also, field trials of these fertilizers should be carried out in the area to determine the specific quantities to be applied


(ISTRC-AB)

175

Comparing arable and plantation crop effects on soil chemical properties of

eroded soils: a case study of Nanka erosion site in Ifite-Nanka, Orumba North

Local Government area, Anambra State.

Okafor Chioma Mars I. M Uzoh, Okolo C.C, Ene Jude, Nwajiaku I.M,

Udegbunam O.N and Obasi, S.C Department of Soil Science, Faculty of Agriculture University of Nigeria, Nsukka.

Abstract

This study was designed to determine and compare the effects of Arable and plantation crop on chemical properties of eroded soilsin Ifite-Nanka, Orumba North local Government Area,

Anambra State. This study was a 6x3 factorial experiment in completely randomized design.Soil samples were collected in six soil conditions (Non eroded arable (Cassava), cashew, Oil

palm and Eroded1, eroded 2 and eroded 3 adjacent to each of the non-eroded sites). Composite samples were collected from the three non eroded (Arable and Plantation) sites to determine

the properties of the soil in addition, profile pits were dug in each of the soil condition (six

profile pits) and soil samples were collected in horizons A, B and C. The samples were used for chemical analysis of the soil. The results were subjected to statistical analysis using a

factorial in completely randomized design. The results showed that % OM decreased from A- horizon to C- horizons andwas highest in Eroded 2 (1.10%) followed by Eroded 3

(0.99%),Oil palm (0.89%), Arable farm land (0.79%), Eroded1 (0.77%) with Cashew (0.49%)plantation having the least % OM content. The exchangeable base cations (Na+,

K+, Ca2+, and Mg2+) were low in all the horizons but did not show a specific pattern of

changes in all excluding Ca2+(in arable and Eroded 2) and Mg2+ (Eroded 1) that decreased and increased down the profile respectively, and also Na+ (in Arable, Eroded 2 and Oil palm)

and K+ (Arable, Eroded 1 and Eroded 2) that decreased down the profile respectively.Al3+

ranged from 0.00 to 1.40meq/100gsoil while H+ ranged from 0.2 to 3.4(Oil palm) down the

profile in the study area. The acidity of this area ranged from slightly acidic to moderately acidic, % total nitrogen ranged from low to moderately high, the Avail. P were very low

apart from Arable (13.06 ppmP in A- horizon), and A- horizon of Eroded 3(5.06 ppmP) that

were moderate and low respectively while the CEC and ECEC of the area were high. All the results obtained showed that soil erosion and land use (Arable and Plantation Crop) affected

soil chemical properties both down the profile and among different soil treatments accessed.


(ISTRC-AB)

176

Support to Agricultural Research for the Development of Strategic Crops in

Africa (SARD-SC)

M.O. Yomeni, N. Mahungu, A. Adebayo, P. Ntawuruhunga and C. Akem

International Institute of Tropical Agriculture

Abstract

SARD-SC is Multi CGIAR project funded by the African Development Bank, piloted by IITA and implemented by IITA, AfrcaRice and ICARDA. It is a 68 million project with a

five years lifespan. Twenty African countries will directly benefit from the project activities

and the others will be the indirect beneficiaries. Four strategic African crops: cassava, maize, wheat and rice are targeted by this project. The SARD-SC project aims to enhance

food and nutrition security and contribute to poverty reduction in Bank’s low income Regional Member Countries. The specific objective is to enhance the productivity and income of

four CAADP’s priority value chains (cassava, maize, rice, and wheat) on a sustainable basis. The project had four components which are development of technology and innovations,

dissemination of technology, capacity building and effective management. The expected outputs

are (1) 20% yield increase in cassava, maize, rice and wheat, (2) Average annual household cash income of $600 from $370 presently and (3) 20% increase in food security (84% from

present 73%) at end of project. SARD-SC cassava component is implemented in Democratic Republic of Congo (DRC), Sierra Leone, Tanzania and Zambia. In order to achieve the

project objectives, regional launching was organized in Kinshasa 12th to 13th February, 2013 during which strategies for the implementation of project activities in the four countries where

cassava is targeted were developed. Between March and April 2013, DRC, Sierra Leone,

Tanzania and Zambia had respectively organized national launches in which government officials, key national partners (NARS, NGOs, Universities, etc…) played active role. This

launching help to the development of country work plans and the selection of key partners based in the project area in each of the countries. Up to date, at least 5 ha of planting

materials has been established in each of the implementing counties A platform of all the cassava actors along the value chain (producers, processors, traders, transporters, input

dealers etc) has been established and is playing a very active role in the improvement of the

cassava subsectors. Good linkages system is being established to improve the communication system which is the key to the success of this project.


(ISTRC-AB)

177

Meeting supply of large volume of improved cassava stems to Nigeria farmers by

IITA: challenges, approach and achievements

1Okechukwu R., G. Tarawali1 and M. Fregene 2

1International Institute of Tropical Agriculture, Ibadan, Nigeria; 2Federal Ministry of Agriculture

and Rural Development, FCT, Nigeria


Abstract

In Nigeria, the Federal Ministry of Agriculture and Rural Development, developed a Cassava Transformation Agenda action plan that calls for cassava value-addition in five value-added chains, namely: 1.2 million tons of high quality cassava flour (HQCF), as partial replacement

for wheat in the bakery and confectionary industry; 230,000 tons of native and modified

starch; 150,000 tons of sweeteners to replace imported sugar; two million tons of dried chips for export and half a million tons of dried feed grade grits for poultry feed; and one billion

liters of fuel ethanol. Satisfying raw material requirement for these additional value-added chains requires another 17 million tons of cassava or a 50% increase in current production;

the increase will be achieved via an increase in productivity from current levels of 11.7 t/ha to 16 t/ha and an addition of 250,000 ha under modern farming. High productivity is perhaps

the most important driver of profitability along the value-added chain. The distribution of

stems of high yielding cassava varieties is therefore a high priority activity for the cassava transformation agenda. By the end of the 2012 planting season, 30 million stems of improved

cassava varieties was expected to be distributed to farmers from supplies by the International Institute of Tropical Agriculture (IITA), Root and Tuber Expansion Programme (RTEP), and

National Root Crops Research Institute (NRCRI) Umudike. This paper presents IITA’s challenges, approach and achievements.

Key words: Cassava Transformation Agenda, High quality cassava flour, IITA



(ISTRC-AB)

178

Evaluation of three sweetpotato genotypes in sand hydroponics for vine

production

Mwanga R.O.M*1, Kyalo G1, Low J2, Ssemakula G.N3and Otazú V4

1International Potato Center (CIP), Box 22274, Kampala, Uganda.2CIP, Box 25171-00603,

Nairobi, Kenya.3National Crops Resources Research Institute, Box 7084, Kampala,

Uganda.4Apartado 1558, Lima 12, Peru

* r.mwanga@cgia r.org

Abstract

Sweetpotato is an important food crop, especially in Asia and Africa. In most developing countries there is no formal seed production program. It is important to improve seed quality,

and to solve the problem of seed shortage. The purpose of this experiment was to evaluate three sweetpotato genotypes, Ejumula, Vita, and Kabode for adaptability to a sand hydroponic

system. The hydroponic system had a polyvinyl chloride (PVC) 220-litre tank connected to a trough with sand by PVC piping with taps watering test plants in the sand with nutrients.

The experiment was conducted at Namulonge, Uganda, in a screen house and field, June to August 2013. Vine multiplication in hydroponics was compared to multiplication in pots in the

screen house and field. Three pathogen-tested, virus-free cuttings of each of the three varieties

were planted in a randomized complete block design with three replicates in hydroponics, field and pots (treatments, T1 to T9). The vines were harvested 89 days after planting.

Sweetpotato variety, Ejumula (T3, T6, T9) was superior for all high vine multiplication indicators, vine length, number of 2-node cuttings, number of 30-cm cuttings, number of

axillary plantlets under hydroponics and field but not in pots. Optimizing hydroponic conditions to produce vines at high rates will make it possible to provide clean stocks of vines for further

multiplication by vine multipliers. However, when the sand hydroponics are efficient in producing vines a study of the economics of their production under local conditions will be

necessary.

Key words: Seed system, vegetative propagation, pathogen-tested, multiplication



(ISTRC-AB)

179

Anticipated potential of nutrient efficient genotypes in the productivity of cassava

in Africa

K. Susan John*, S.U. Shanida Beegum,**M.N. Sheela***and G. Suja*

*Principal Scientists, Division of Crop Production, Central Tuber Crops Research Institute

(ICAR), Thiruvananthapuram, 695 017, Kerala, India, email:[email protected]

** Research Scholar, Division of Crop Production, Central Tuber Crops Research Institute

(ICAR), Thiruvananthapuram, 695 017,Kerala, India, email:[email protected]

*** Principal Scientist & Head, Division of Crop Improvement, Central Tuber Crops Research

Institute, (ICAR) Thiruvananthapuram, 695 017, Kerala, India,

emai l :sheelactcri@yahoo .co .in

Abstract

A continent like Africa, where tuber crops in general and cassava in particular are grown in

marginally fertile soils with low inputs, our experience at CTCRI with nutrient use efficient (NUE) cassava genotypes anticipate a better scope in maintaining its productivity even under

low innate fertility status of that soils. Determination of the agronomic and physiological efficiency of 100 elite cassava genotypes resulted in the selection of six K efficient lines, 3

each for edible and industrial uses. Evaluation of these genotypes at 4 levels (0,50,100, 150 kg ha-1) of K for 3 consecutive years and computation of NUE parameters viz., agronomic,

physiological, agro physiological,apparent recovery and utilization efficiencies, harvest index,

K harvest index, K uptake ratio, K utilization for biomass and tuber and physiologic parameters viz. , RGR, CGR,TBR, LAI other than tuber yield, tuber quality, drought, mosaic tolerance

and plant architecture resulted in identifying Aniyoor and 7 III E3-5 as K efficient for consumption and industrial purposes respectively. These genotypes could perform better at

K50 and K0at which the root biomass and LAI supported their efficacy to scavenge the fixed native soil K and its better utilization. Screening 300 land races from the germplasm

could select 15NUE lines which included NPK (7), NP (3) and PK (5) efficient. Field and pot trials with three NPK efficient lines viz., Ac. No. 130, Ac. No. 766 and Ac. No. 905

indicated higher potential of Ac. No. 130in low input management (soil test based) and in

higher carbon sequestration.

mailto:email:[email protected]




(ISTRC-AB)

180

Status of ginger production in the Rain Forest Agro Ecological zone of Nigeria

Ewuziem, J.E. and Ironkwe, A.G

National Root Crops Research Institute Umudike, Nigeria

juziem2000@yahoo .co m

Abstract

The study was conducted in the rain forest agro ecological zone of Nigeria, with the aim of assessing the level of involvement of farmers in ginger (Zingiber officinale Rosc.) cultivation

in the study area. Imo, a southeastern State in the rainforest agro ecology of Nigeria was purposively selected for the study. Twenty (20) farmers each from the three agricultural

zones of the state within the forest agroecology, namely: Okigwe, Orlu and Owerri, giving a total of sixty (60) were selected for the study. Questionnaires and oral interviews were used

to elicit information on the farmers’ socioeconomic characteristics and other relevant

production indicators. Data collected were analyzed using descriptive statistics. The results showed that majority of the farmers were males (78.1%), aged between 55-65years (43%)

with over 30 years of farming experience. Most of these farmers abandoned ginger cultivation due to some reasons, among which are; planting wrong varieties of ginger (Zingiber officinale

Rosc.)(84%), poor markets (75%) and inadequate information on production technologies (63%).. Further investigations revealed that majority of the farmers (90%) were cultivating

the wild ginger which does not possess the pungent qualities of the known Nigerian ginger

hence the poor demand. It is recommended that sensitization campaign be carried out by the National Root Crops Research Institute Umudike, in the agro ecological zone to assist farmers

identify and use thedesired variety of ginger (Zingiber officinale Rosc) for planting.

Key words: Ginger, Planting, Agro Ecology, Rain Forest, Farmers.




(ISTRC-AB)

181

Effects of environmental degradation on profitability of cassava production in

Southeast Nigeria

Bolarinwa, O. K.1 and Osun, Taiwo2

1Regal College P. O. Box 855, Sagamu, Ogun State Nigeria 2 Institute of Food Economics and Consumption Studies,

University of Kiel, Olshausenstraße 40, 24098 Kiel, Germany

Email ; babbirinwa@yahoo .com

Abstract

This paper examines the effects of soil erosion on profitability of cassava production in Enugu State, Nigeria. The study specifically compared the costs and returns of the farmers

operating on eroded and non-eroded farms and explicitly analyzed the factors influencing

profitability of cassava farming enterprise using partial budgetary technique and regression analysis. A multistage sampling procedure was used to select 200 cassava farmers for the

study. Primary data were collected on respondents’ age, sex, educational background, farm size, as well as on quantities and prices of inputs and outputs using pre-tested questionnaire.

Partial budgetary analysis showed that farmers operating on eroded farms recorded lower crop yield resulting in a significant difference (p<0.05) between the average gross margin

earned per hectare on non-eroded (N185, 553) and eroded (N152, 312) farms. Regression

model estimates showed that farm size, labor, input-usage and access to extension services positively and significantly influenced profitability of cassava farming enterprise; whereas

incidence of soil erosion and large household size have negative effects on profitability of cassava farming enterprise in the study area. Cassava farmers in the study area could

substantially increase their profit if farmers they have access to more land, credit to purchase farm inputs and extension services geared towards good agricultural practices and soil

conservation methods. It is also pertinent for government to design and implement special

schemes to control and mitigate the effect of soil erosion in order to forestall continuous degradation of arable lands.

Key Words: Profitability; Budgetary technique; Multiple regression; Soil erosion; Cassava

farmers



(ISTRC-AB)

182

Combined effect of organic/inorganic fertilizer mixtures on turmeric production in

a rainforest agro-ecology of Nigeria

Olojede, A.O., Nwokocha, C.C., Ano, A.O., Akinpelu, A.O.


PMB 7006, Umuahia

Abia state-Nigeria yemiolo jede@yahoo .com;

yemiolo jede@gmail .com

Abstract A field experiment was conducted in the research farm of the National Root Crops Research

Institute, Umudike, Nigeria in 2011 and 2012 cropping seasons, to assess the effect of different combinations of NPK (15:15:15) fertilizer and poultry manure (PM) on the yield

of turmeric (Curcuma longa Linn). The experiment was laid out in a randomized complete block design (RCBD) with 4 replicates. The treatment comprised; 0 kg/ha NPK + 0 t/ha

PM; 80 kg/ha NPK + 6.4 t/ha PM; 160 kg/ha NPK + 4.8 t/ha PM; 240 kg/ha NPK + 3.2 t/ ha PM; 320 kg/ha NPK + 1.6 t/ha PM; 400 kg/ha NPK; and 8 t/ha PM. Planting was done

on raised beds of 3 m x 3 m and using a plant spacing of 50 cm x 30 cm. All plots received 12

t/ha of elephant grass straw (Panicum maximum) as mulch at planting. Routine agronomic practices were carried out with the treatments applied at 8 weeks after planting. The crop

was harvested 7 MAP and yield calculated. Combined analysis of the two years results showed that fertilizer mixture significantly (P < 0.05) influenced mother rhizome and total

rhizome yields. Application of 8 t/ha PM gave the highest mother rhizome yield (6.11 t/ha) and total rhizome yield (23.05 t/ha). For optimum turmeric yield under integrated nutrient

management, application of 320 kg/ha NPK + 1.6 t/ha PM is recommended under Umudike

conditions.

Key words: fertilizer mixtures, turmeric, rainforest agro-ecology





(ISTRC-AB)

183

Influence of soil moisture stress on vegetative growth and root yield of some

selected cassava genotypes under green house condition

Adetoro N.A., Parkes E., Oworu O.O., Aina O., Iluebbey P., Kulakow P.

International Institute of Tropical Agriculture Ibadan ( IITA).

Abstract

Improving tuber yield has always been one of the major thrusts in cassava improvement programmes, and the wide variability among genotypes for shoot and root characteristics

can be utilized as an important tool. This study was carried out to determine how variation in shoot and root characteristics affect tuber yield and the influence of soil moisture stress on

the vegetative growth and yield of cassava genotypes. In the greenhouse, twelve genotypes selected on the basis of field performance for tuber yield and number were evaluated at

three moisture conditions of 75% ( control ), 50% and 25% field capacity ( FC) using a completely randomized design with factorial arrangement ( variety and moisture level ) and

replicated three times. Moisture stress affects the vegetative growth and root yield. Significant

differences (P< 0.05) existed among genotypes and moisture regimes for plant height stem girth, root weight, root number and shoot weight from which estimates of variance components

were generated. The higher stress level (25% FC) resulted in a greater reduction in vegetative growth (P late 1) than the moderate stress level of 50% FC, but moisture levels was uniform

over time for plant height and stem girth (Fig.1), but the response to moisture levels varied widely among genotypes for root weight at harvesting 24 WAP indicating that genotypes

experience a higher stress condition. Genotypes IITA TMS 010040,980581 and 920326 were

identified as having good drought tolerant abilities.

Keywords: Cassava, genotype, moisture stress,


(ISTRC-AB)

184

Developing appropriate fertilizer management options for sweetpotato

production in the agro-ecozone of Ghana

Felix Owusu Ababio CSIR-Soil Research Insti tute , Accra Office

Abstract

With a production level of 122 million tonnes, Sweetpotato is ranked as the third root and tuber crop in the world after potato and cassava. Though the average yield is very low (8 Mt/

ha), it is gaining a lot of recognition and importance especially in the Central, Volta and

Northern regions of Ghana. This is because it can grow on poor fragile soils and have low input requirements. It is a source of energy in the dietary staple of the rural poor and provides

a regular source of income for smallholder farmers and rural traders. The challenge was the poor fertility status of the soils which are used for its continuous cultivation. Continuous

cultivation of Sweetpotato on these fragile soils has rendered the soils very unhealthy in terms of its fertility status. It is known that about 16.8t/ha of Sweetpotato cultivation deprives

the soil of about 17kg, 19kg and 108kg of N, P O and K O of nutrients respectively.So to 2 5 2

sustain cultivation of sweetpotato on the same piece of land for a longer period, 2 year on farm study using participatory technology development approach was done to evaluate different appropriate fertilizer management options (inorganic and organic) to improve sweetpotato

production in the coastal belt (Central Region) of Ghana. A split plot design with soil

amendments as main plot treatments and sweetpotato cultivars as sub-plot treatments was used. Results showed that the application of 2.5t/h poultry manure at the ridge preparatory

stage plus 30-15-60/ha N-P O -K O 4-5 WAP will give an optimum root yield of sweetpotato 2 5 2

(20-25t/ha) and also application of NPK (30-15-15) plus poultry manure (2.5t/ha) give very high biomass yield as fodder and enhanced soil fertility.


(ISTRC-AB)

185

Variation of Harvest Index and Dry Matter Content of Yam Bean (Pachyrhizus

spp) Accessions in two major Agro Ecological Zones of Uganda

R. Agaba1, P. Tukamuhabwa1, P. Rubaihayo1, S. Tumwegamire 2, and W.J. Gruneberg3

1Department of Agricultural Production, College of Agricultural and Environmental Sciences,

Makerere University P.O Box 7062, Kampala, Uganda. Email: [email protected] 2IITA Tanzania, P.O Box 34441, Dar-Es-Salaam, Tanzania. Email: [email protected] 3Centro Internacional de la Papa (CIP), Av La Molina 1895, Apartado 1558, Lima 12, Peru.

Email: [email protected]

rondessblessed@gmai l .co m

Abstract

The yam bean (Pachyrhizus spp.) is a legume root crop and a close relative to soy bean taxonomically. The genus comprises three cultivated species locally grown in Central America,

South America and Asia but interspecific hybrids can be easily developed. In Uganda, the crop was recently introduced to supplement food sources and offer an alternative storage

root crop rich in proteins, Iron, zinc and vitamins. Yam bean is propagated by true seed, has high nitrogen-fixing capacity and high storage root yields however, the storage root dry matter

content of yam beans is very low (SRDM less than 10%) which may limit adoption and utilization. This study was conducted to determine variance components for dry matter and

harvest index (HI) among the yam bean accessions to identify high yielding genotypes as

base population for hybridization. Thirty two yam bean accessions were evaluated in two different agro-ecological locations and data analysed using General Linear Model in Minitab

software version 14. Preliminary results show the highest mean SRDM (24.9%) in 209033 under the semi arid conditions of Serere and the lowest (7.0) in 209046 under wet tropical

conditions of Namulonge. The HI was however highest (100%) at Namulonge and lowest (29.6%) at Serere. Similarly, location and genotypic factors significantly influences (p<0.05)

SRDM and HI irrespective of the variety. Although HI is lower in the dryer environment, SRDM is higher. This means that when targeting high dry matter, semi arid environment is

more suitable.

Key words: Dry matter content, Harvest Index, Yam bean (Pachyrhizus spp.), Uganda







(ISTRC-AB)

186

Yield and Micronutrient uptake of white yam (Dioscorearotundata L. Poir) as

influence by organomineral fertilizer ammendment on an alfisol in Ibadan South

western Nigeria

Lawal O.I.1, G.O. Adeoye 2, R. Asiedu,3 Ojeniyi, S.O.4 Atayese. M.O.1 and A.O.

Olaiya1

1Department of plant physiology and crop production, Federal University of Agriculture,

Abeokuta, Nigeria 2Department ofAgronomy, University of Ibadan.

3International Institute ofTropicalAgriculture, Ibadan. 4Federal University of Technology Akure

* [email protected], [email protected], [email protected]

Abstract

Fertilizer use for increased and sustainable yam production in the country is grossly inadequate and inefficient. Most research focused on the macronutrients in crop production, forgeting

the importance of micronutients in plant nutrition. Field trials were conducted in 2004 and 2005 wet seasons, at the International Institute of Tropical Agriculture Ibadan Research

Farm to determine the influenceof organo-mineral fertilizer on some Micronutrient uptake of white yam in an organic-based production system. Four cultivars of white yam: “Adaka”,

“Amula” , “Danacha” and “Omiefun” were each subjected to 10 fertilizer treatments comprising sole Organic fertilizer (OF), mineral (NPK 12-12-12) fertilizers combinations of

the two (organo-mineral) and control, 2.5, and 5.0 t/ha OF; 0.15, 0.3 and 0.45 t/ha /ha NPK;

1.75 t/ha OF+0.15 t/ha kg/ha NPK; 2.5 t/ha OF+0.15 t /ha NPK; 2.5 t/ha OF+0.3 t/ha /ha NPK and 5.0 t/ha OF+0.3 t/ha /ha NPK. The trials were conducted at Ibadan

(OxicKandiustalf), Southwest Nigeria. The experiment was a split-plot in randomized complete block design with four replicates. White yam cultivars and fertilizer rates were main and sub-

plot treatments, respectively. Tuber yield, Zn, Cu and cl uptake were assessed. Data obtained over two years were analyzed using analyses of variance; means were separated using

SED. “Amula” had the highest tuber yield of 10.7 and 22.1 t/ha in 2004 and 2005 respectively.

Four fertilizer treatments (5.0 t/ha OF, 0.45 t/ha NPK, 2.5 t/ha OF+0.3 t/ha NPK, 5.0 t/ha OF+0.3 t/ha NPK) significantly (P < 0.05) improved the growth and yield of white yam

compared to the control. Fertilizer treatment at 5.0 t/ha OF + 0.15 t /ha NPK produced the highest tuber yield of 16.0 t/ha in 2004 and 20.4 t/ha in 2005. They were significantly (P<0.05)

higher than the control plots in the two years. Similarly, the same fertilizer treatment had the highest Zn, Cu and Cl uptake for both years. There wereZn, Cu and Cl uptakes of 5.8, 7.2

and 6.3 g/plant respectively in 2005 and were significantly (P< 0.05) higher than the control.

Fertilizer treatment at 5.0 t/ha OF+0.3 t /ha NPK was the best with reference to tuber yield and nutrient uptake. “Amula” had the highest tuber yield during both years of study.

Key words: Dioscorea rotundata, Fertilizers, Soil type, Tuber yield, micronutrient uptake.







(ISTRC-AB)

187

Seed system lessons learned from Marando Bora in lakes zone, Tanzania

Stephen Walsh and Lembris Laizer

Catholic Relief Services

Abstract

This paper and accompanying presentation will outline the key lessons learned from the Marando Bora project on getting seed systems moving through a decentralized producer &

seller network back-stopped with research and extension support. The Marando Bora project was funded under the Sweetpotato Action for Security and Health in Africa (SASHA) from

2009-2011 to improve the food security of at least 150,000 families by providing farmers

with quality seed of improved sweetpotato varieties in a timely fashion. This Project was implemented in in the Lakes Zone of Tanzania and the initiative brought together four Tanzanian

NGO’s (RUDDO, BRAC, TAHEA, KIMKUMAKA), two National Research partners (Agricultural Research and Development Institutes at Ukiliguru and Maruku), the International

Potato Center (CIP) as over-all project coordinator, Helen Keller International for development of educational messages and advertising, and Catholic Relief Services as field coordinator.

The paper and presentation will be based on project documents and on information and

insights provided by project staff and participants. Under Marando Bora, decentralized vine multipliers performed well below project expectations and partners had to employ a mass

dissemination strategy in the last year of the project in order to achieve 50% of the initial project target. Outputs related to advertising and the establishment of field demonstrations

was late. Subsidies to producers were not systematic. Communication and collaboration among the network of partner organizations was a challenge.

Key conclusions are the importance of effective research and development partnerships, the

consequence of varietal choice and validation in seed projects that have scale as an objective, the value of developing and implementing disease and seed system quality management

protocols, the significance of selection criteria and managing incentives and subsidies with vine producers. This paper will review some of the most acute lessons learned applicable for

practitioners: tailored and targeted subsidies can promote entrepreneurship; timely and effective advertising of new varieties and vine producers can raise effective demand and sales; simple

quality control protocols can improve vine production; and documentation and traceability of

planting material from research managed bulking sites promotes effective supply chain management.

Key words: entrepreneurship, quality control protocols, research and development

partnerships


(ISTRC-AB)

188

Profitability and technical efficiency of cassava (Manihot esculanta) production in

Ndokwa west local government area of delta state, Nigeria

1Eze, A.V., 1Nwibo, S.U., 2Okolo, C.C*., 2Ezeaku, P. I., 2Ezeudo, V.C., 3Chukwudi,

P.U., 2Agbo, S.U and 2Eze, N. C 1Department of Agricultural Economics Management and Extension Ebonyi State University,

Abakaliki, Nigeria 2Department of Soil Science, University of Nigeria, Nsukka, Nigeria

3Department of Crop Science, University of Nigeria, Nsukka, Nigeria

*[email protected]

Abstract

The study analyzed the profitability and technical efficiency of cassava production in Ndokwa West Local Government Area of Delta state. A multistage random sampling was used to

select a total of 120 respondents used for the study. Data used for the study was from primary source, which was collected using a well structured questionnaire. Both descriptive

and inferential statistics were used to analyze the data. Based on the objective of the study, Objective i, and ii were achieved using descriptive statistics, objective iii was analyzed using

multiple regression analysis, while objective iv was realized using gross margin analysis and finally, objective v was realized using mean score. The result obtained showed that females

(52.5%) are more than males. Majority (50%) of the respondents are married with an average

household size of 6. The result also shows that the cassava farmers are within their active economic age with a mean age of 42 years. The farmers had acquired reasonable years of

farming experience with an average of 10 years. More than half of the farmers had attended formal education and earn average annual income of N180, 000.00k. The production systems

practiced by the farmers was mono cropping. Cassava production was profitable in the area with a profit margin of N200, 400.00k/hectare. The Benefit Cost Ratio shows that in every

N1.0k invested by farmers, N1.0k was realized as profit. The multiple regression result showed R2 value of 0.833 implying that 83.3% of total variation in the total output of cassava

production was explained by the variables included in the model. The coefficients of farm

size, labour and cassava stem were positively signed. Farm size, labour, fertilizer and cassava cuttings were underutilized because their efficiency index was greater than one. The cassava

farmers identified some of the farming constraints as: lack of access to credit, high cost of transportation, inadequate fertilizer supply and poor extension services. Based on the findings,

it is recommended that farmers should organize themselves into cooperative societies so as to access credit, viable extension service should be provided to bridge the extension need of

the farmers and effective transportation system put in place to ease evacuation of cassava

produce from the farm.

Key words: Profitability, technical efficiency, cassava, farmers, Ndokwa West Local

Government Area



(ISTRC-AB)

Seed System Innovations in the Great Lakes Cassava Initiative (GLCI)

Stephen Walsh1, Phemba Phezo2, Elia Marandu3, Julian Smith4, Dai Peters5 and

Michael Potts6

[email protected]), 1(CRS / GLCI DRC Country Program Manager, [email protected]),

2(CRS / GLCI Tanzania Country Program Manager, [email protected]), 3(Sector Lead, International Development, The Food and Environment Research Agency,

4julian.smith@fera .gsi.gov.uk), 5(CRS / GLCI Project Director 2009-2012, [email protected]),

6(CRS / GLCI Project Director 2007 – 2009, [email protected]).

Abstract

GLCI was a four year project operating across 6 countries. GLCI established a network of more than 50 partners encompassing national and international research, national pant

protection, government agricultural extension, and non-governmental organizations tasked

with identifying, producing, validating, and delivering improved disease tolerant (cassava mosaic and cassava brown streak) varieties to 1.2 million farming families in East and Central Africa.

This paper discusses key lessons learned in planting material production and delivery through five innovative approaches used in the GLCI seed system: decentralized production to attain

scale, source site sampling and diagnostic testing to mitigate CBSD risk, the benefits and limitations of visual in-field quality management protocols (QMP) to validate fields before

dissemination, and transparent and participatory dissemination processes. Furthermore, the

paper presents challenges with these innovations and provides practical suggestions for practitioners which may be applicable to other vegetatively propagated crops.

189








mailto:@crs.org


(ISTRC-AB)

190

Cassava Seed Regulations–Multi-Stakeholder Engagement to Increase the

Relevance and Application of Stem Quality Standards. Data and insights drawn

from Sustainable Cassava Seed System (SCSS) Project in Nigeria

Iruansi Itoandon1, Lateef Towolawi2, Stephen Walsh3, Charles Iyangbe 4,

1CRS Nigeria, SCSS Program Manager ([email protected]), 2NASC Desk Officer ([email protected]),

3CRS Agricultural Advisor ([email protected]),

4CRS Nigeria Head of Agriculture ([email protected]).

Abstract

SCSS is a four-year project (May 2012 – April 2016) operating in Benue and Oyo States aiming to develop commercial and sustainable cassava stem market where farmers and not

projects, NGO’s, or government are buying stems. A key activity in the project is to work with a variety of cassava partners (seed certification, research, seed entrepreneurs,

development partners) to develop cassava stem multiplication regulations which meet the interests of different stakeholders and have a beneficial effect on farmers. This paper will

discusses the development and application of cassava seed regulations in Nigeria under SCSS, on the process of developing, applying, and refining a cassava stem protocol which

meets different objectives for different organizations, will highlight some of the challenges

and key milestones in assessing the application and utility of the protocol for different partners, and present some preliminary insights on challenges of mainstreaming and institutionalizing

seed regulations aimed at serving multiple partners and small farmers.







(ISTRC-AB)

191

Sustainable Cassava Seed Systems in Nigeria–A project overview with key

achievements and lessons learned to date

Itoandon1, S. Owoyemi1, C.Iyangbe1, S. Walsh2

1 Catholic Relief Service/Nigeria Program Office

2 Catholic Relief Services/Regional Office, Kenya

Abstract

The Sustainable Cassava Seed System (SCSS) Project is a four initiative supported by the Bill and Melinda Gates Foundation (BMGF) to strengthen the cassava supply chain and public and private extension services with a focus on smallholder seed entrepreneurs as

commercial producers of improved and certified cassava seed and farmers as consumers of

seed and related services. SCSS is aimed at developing a commercial cassava seed system targeting small farmers through promoting a network of cassava seed entrepreneurs linked

with research and development partners. SCSS facilitates private and public organizations to work collaboratively to improve the commercialization of cassava seed system and to

collectively identify and address bottlenecks in the seed system which may hinder commercial opportunities for seed entrepreneurs. The project is in its second season. This poster will

outline the SCSS objectives and partners, showcase some key SCSS activities and

achievements to date, and outline constraints and lessons learned. Key outputs to date include the identification and training of 33 seed entrepreneurs, 4 input dealer and 4 private

and 8 public extension service providers in 4 LGAs, sourcing quality foundation seed for the establishment of a total 33 ha seed multiplication field and 6 ha demonstration fields, working

with NASC, NRCRI, and IITA to develop a cassava seed protocol for Nigeria which SCSS will work to apply, and facilitating a partner network committed to the objectives of SCSS.


(ISTRC-AB)

192

Physico-chemical properties of salad cream stabilized with cassava and potato

starches

Eke-Ejiofor, J; Williams, I. J and Owuno, F.

Department of Food Science and Technology,

Rivers State University of Science and Technology, Port-Harcourt, Rivers State, Nigeria.

[email protected] .uk

Abstract

Salad cream is a ready made creamy-white dressing with a flowing consistency for eating mixed vegetables with modified maize starch as the base raw material. However starches

from other sources such as tubers are readily available, high yielding and cheap and can be

made into more utilizable and value added form. Therefore the purpose of this study was to determine the physico-chemical properties of cassava and potato starches with the primary

aim of diversifying the usage of these starches for household food consumption. Cassava and potatoes was collected from Rivers State University of Science and Technology farm

and National Root Crop Research Institute, Rivers State respectively. Starch was extracted from these tubers and used in the production of salad cream with other ingredients using

standard procedures. The salad cream was subjected to chemical and sensory analysis as

well as viscosity in psa, while commercial salad cream was used as control. Chemical properties of the samples were significantly different (p<0.05) in moisture (57.84-64.88), dry matter

(42.16 -54.69). Total solids (35.12 -42.16), starch (6.40 – 14.41), fat (25.17 -28.15) and total available carbohydrate TCA (7.11-17.32). While titratable acidity, pH protein and ash showed

no significant (p>0.05) difference, ranging from 0.02-0.89, 3.14-3.50, 0.23- 0.35 and 1.62- 1.83 respectively. The viscosity of the salad cream was non-Newtonian with potato starch

salad cream having the highest viscosities at 6, 12, 30 and 60rpm. Sensory evaluation showed

a significant difference (p<0.05) in color, texture and spreadability, while odour texture and overall acceptability showed no significant (p>0.05) difference between the samples and the

control. This study has shown that tuber starches are also desirable and acceptable for the production of salad cream.

Keyword: salad cream, cassava, potato, starches, chemical, sensory evaluation.



(ISTRC-AB)

193

Effect of bio-fertilizers in the growth and yield of sweetpotato

C. M. Tfwala

Ministry of Agriculture, Department of Agricultural Research and Specialist Services, P.O. Box 4,

Malkerns, Swaziland

[email protected]

Abstract

Sweetpotato is one of the major food crops in Swaziland. The use of fertilizers when growing the crop has not been fully explored in Swaziland. In fact, the farmers believe that the palatability of the tubers is compromised by the use of fertilizers. An experiment to evaluate

different soil amendment treatments was conducted at Malkerns Research Station, Swaziland

during the 2011/2012 and 2012/2013 cropping seasons. One sweetpotato variety (Kenya) was planted on seven soil amendment treatments including kraal manure, synthetic fertilizer

(N:P:K) and bio-fertilizers. The use of bio-fertilizers, especially when combined with kraal manure proved to be equally capable with the synthetic fertilizers in increasing the tuberous

root yield as well as the above ground biomass accumulation. Tuberous root yield of up to 40.8 ton/ha were obtained with the use of kraal manure and pro-plant, significantly higher

(p<0.05) than where no soil amendment treatment was applied, which was the lowest (29.7

ton/ha). The rest of the treatments were intermediate and not significantly different from the highest and lowest yielders. The combination of biofertilizers and synthetic fertilizer did not

prove to be beneficial. The findings also revealed that there was no effect of the soil amendment on the tuberous roots numberand their palatability. The conclusion was that bio-fertilizers can

be used for sweetpotato production.



(ISTRC-AB)

194

Productivity and field disease reaction of biofortified cassava genotypes in

Nigeria

Bello, A.A.1,2, Parkes, E.1, Aina, O.O.1,Maroya, N.G1, Kolawole, R.2, Akoroda,

M.O.2, Kulakow, P.1,*

1International Institute of Tropical Agriculture (IITA), Ibadan. 2 Department of Agronomy,

University of Ibadan, Ibadan, Nigeria.

[email protected], [email protected], [email protected], [email protected],

[email protected],[email protected], p [email protected].

* [email protected]

Abstract

The objective of this study was to assess the productivity of some improved cassava genotypes for fresh root yield, total carotenoid content, dry matter content, dry yield, number of roots per plot, harvest index and their field reactions to cassava mosaic disease (CMD) and cassava

bacteria blight (CBB). Twelve improved proVitamin A enhanced cassava (Manihot esculenta

Crantz) genotypes along with two checks were evaluated for two years in three agro-ecological zones in Nigeria. The experimental design was a randomised complete block design with

four replications. Differences (p < 0.001) were observed among genotypes for all traits. Partitioning of variance components revealed that genotype by location contributed largely to

the total variation observed for genotype by environment interaction (G X E) for all the traits. Genotypes and locations effects were also significant. Genotypes TMS-IITA-IBA062116,

TMS-IITA-IBA061856 and TMS-IITA-IBA061404 showed high tolerance to CBB and CMD

infections. Genotypes TMS-IITA-IBA062116, TMS-IITA-IBA30572 and TMS-IITA- IB061577 were highest for fresh root yield across the three agro-ecological zones.

Key words: biofortified, productivity, disease reaction, proVitamin A, agro-ecological zones.










(ISTRC-AB)

195

,

, ,

, ,

BREEDING

Strategies to enhance the use of Inbreds and Genetic Diversity to produce

Superior Cassava Varieties

Okoro Perpetua1,2 , Kulakow Peter1, Rabbi Ismail1 Egesi Chiedozie 2

Essie

Blay3 I.K Asante3

Gracen Vernon4 Otene J.J Iduh5

1 International Institute of tropical Agriculture PMB 5320, Oyo Road, Ibadan, Nigeria

2 National Root Crops Research Institute Umudike P.M.B 7006, Umuahia Abia Nigeria

3 University of Ghana P.O.Box 25 Legon Accra

4 Cornel University Ithaca, USA

5 University o f Ibadan Ibadan Nigeria

Abstract

In order to develop cassava varieties that will meet farmers’ diverse preferences and fit into

the different cropping systems, it is essential to adopt a Participatory Rural Appraisal (PRA) approach where farmers will be involved at all stages of variety development, identify

agronomic traits to be improved, and help to set the breeding objectives. Most researches carried out in Research Institutes are not geared towards solving the immediate needs of

farmers, since most are planned and executed without farmer’s input. Hence this research

to conduct a survey to determine farmers’ perception of different cassava varieties and characteristics for preferred varieties in Edo State is to achieve a demand driven research

that will generate appropriate linkage between technologies disseminated and the farmer’s diverse needs. PRA approach was employed in obtaining information from farmers through

questionnaire administration and focus group discussions. Edo State is zoned into three. In each of these zones, there was a random sampling of two out of eight LGA’s, the number of

farmers that were administered to ranged from 14-80.


(ISTRC-AB)

196

Evaluation of local germplasm for agronomic performance, diseases expression

and root qualities

T. Ayankanmi, P. kulakow, E. Parkes, R. Ismail, O. Aina, P. Iluebbey and A. Ikpan

Abstract

Cassava (Manihot esculenta Crantz) is a popular, highly valued starch storage root and

widely grown crop in tropical Africa. With the increasing importance of cassava even around the world for human consumption, animal feed and industrial uses, there will be an increasing

need for a wide range of genetic diversity to develop cultivars possessing specific characteristics and good adaptation to different ecology. In order to increase the genetic base and diversity

for breeding for cassava with increasing desirable traits, such as high productivity, disease resistance and quality root for food (man and animal) and industrial purposes, 1627 accessions

from local collections were evaluated in 2011/2013 seasons at 2 locations for Cassava Mosaic Disease (CMD), Cassava bacterial blight (CBB), stands at harvest, root number, fresh yield,

Harvest index and Dry matter. The results show highly significant genotypic effectsacross

thetested parameters <0.0001 (Wilk lambda statistic). The result also shows the proportion of variation in response variables not explained by location effect as 91% while the year

effect is 75%. The mean dry matter by specific gravity ranges between 16.6% and 48.3%; Cassava Mosaic Disease and Cassava Bacterial Blight score range was 1 and 4.5; the

harvest index value was between 0.0 and 0.8; while the mean fresh yield ranges between 0.4t/ha and 29.2t/ha.The evaluation will help in the selection of superior clones with desirable

agronomic traits,thus facilitating their use in breeding program.

Keywords: Evaluation, local germplasm, agronomic parameters, cassava disease,


(ISTRC-AB)

197

Flow behavior of three parts of yam tuber starch during the tuber growth

Kouadio Claver Degbeu*1, Yao Denis N’dri1 and N’guessan Georges Amani1

1University of Nangui Abrogoua (ex Abobo-Adjame), Faculty of Foods Sciences and

Technologies, Laboratory of Biochemical and Food Technology of Tropical Products, Abidjan,

Côte d’Ivoire; 02 BP 801 Abidjan 02, Fax: (225) 20 30 43 00 * [email protected] Cel: (225) 08 00 17 07

Abstracts

Yam starch properties have been investigated by several studies on the whole tuber at maturity. However, the complexity of yam tuber led some authors to study its polarity along the longitudinal axis, and the harvested time. The tuber maturity according to the nutriments

content does not coincide generally with the harvested time. Also differences on the granule

size distribution and yam parenchyma along the longitudinal axis have been observed. So this investigation aimed to show the rheological variation of yam starch during the growth period.

Two varieties of Dioscorea cayenensis: kponan and kangba were grown in nursery gardener sachet (40 cm x 40 cm) and arranged (1 m x 0.5 m). Six tubers were harvested randomly at

16; 18; 20; 22; 24 and 26 weeks after planting date. Each tuber was measured and sectioned into three parts (proximal, middle and distal) and the starch extracted from them. Flow

measurement was carried out with a rheoviscosimeter Brookfield DV-III Ultra (model RV, Chicago) at varying speed (1 rpm to 200 rpm). The viscosity ratio had been calculated in

triplicate. The viscosity decreased when the rotational speed increased for all samples. But

some differences have being observed at beginning of the test. The viscosity increased at low speed (0.3 to 1.3rpm) for some samples. The viscosity ratio increased with the tuber

maturity (2.37 to 10.23). The flow behavior of yam starch of three tuber parts did not influenced by the maturity period. at maturity, the viscosity ratio was high for all tuber parts.

Keywords: starch, tubers parts, viscosity, yam tuber,




(ISTRC-AB)

198

Morphological and agronomic characterization of root forming legume

species in Uganda

P. Tukamuhabwa1*, E. Oyesigye 1, B. Heider3, S. Tumwegamire 2, and W.J.

Gruneberg3

1Makerere University, School of Agricultural and Environmental Sciences, Department of

Agricultural Production, P.O Box 7062, Kampala, Uganda. 2International Potato Centre’s (CIP) Uganda, P.O Box 22274, Kampala, Uganda. Email:

[email protected] 3International Potato Centre (CIP), Av La Molina 1895, Apartado 1558, Lima 12, Peru. Email:

[email protected]; [email protected]

* [email protected]

Abstract

Many root forming legume crops have been recognized for their food and nutritional importance, but have remained neglected. The current study aimed at introducing and

characterizing different root forming legume species as an entry point for adaptability and

breeding research on the target species. Three different species, namely Vigna vexillata [6 accessions of which four came from International Center for Tropical Agriculture (CIAT)

and two from Meise Botanical garden in Belgium], Sphenostylis stenocarpa [3 accessions from International Institute Tropical Agriculture (IITA)] and Psophocarpus spp [3 accessions

from The World Vegetable Center (AVRDC)] were introduced in Uganda in 2011. All the eleven accessions were grown in single row nurseries at Makerere University Research

Institute, Kabanyolo, Uganda. Data was recorded on both morphological and agronomic

traits. Preliminary results showed that all the accessions were climbers with exception of one Vigna vexillate accession which was prostrate. It was observed that only accessions of

Psophocarpus spp could form roots. The root yield ranged from 137 to 444 grams per plant. The fruits of accessions VI034627, VI034777 and VI038092 from AVRDC were capsules

while the rest of the accessions formed pods. All the accessions exhibited pod dehiscence at harvesting maturity. The mean 100 seed weight was 29g, 32.5g and <0.01 g for Psophocarpus

spp, Sphenostylis stenocarpa spp and Vigina vexillate respectively. More studies should

be conducted to verify the potential of these root forming legumes.

Key words: Accession, Psophocarpus, Sphenostylis stenocarpa spp, Vigina vexillata.






(ISTRC-AB)

199

Yield responses of sweetpotato (Ipomoea batatas) and soyabean (Glycine max)

intercrop to nitrogen levels in south eastern Nigeria.

Obasi C.P, I.I.M Nwankwo, T.C Madu National

Root Crop Research Institute, Umudike Nigeria

[email protected]

Abstract

A study was carried out during the 2006 and 2007 wet seasons in the low land humid forest zone of south-eastern Nigeria to investigate the effects of four nitrogen (N) levels

(0,40,80,120kg/ha ) on soybean and sweet potato intercrop laid out in a 2 x 4 factorial in

RCBD. Sweetpotato variety used was Tis 87/0087 and that of soybean was TG X 184-4E. Result showed that in both years sole cropping differs significantly (P< 0.05) from intercrop.

Yield increased significantly with increase in N application up to the highest rate. The revenue in terms of gross monetary returns (using mean of the two years) in naira( ¦ ) achieved due

to the combination of the crops were highest in N application of 80 kg and 120 kg N per hectare (¦ 11,124,325 and ¦ 14,259,760 respectively). Therefore, 80 kg N was recommended

since there were no significant differences between the yield in 80 and 120 kg N, considering

the high cost of fertilizer which is not readily available to the farmers.




(ISTRC-AB)

200

Towards the development of Cryopreservation protocol for Solenostemon

rotundifolius: Impact of pre-treatment

Marian. D. Quain

CSIR-Crops Research Institute, P. O. Box 3785, Kumasi, Ghana.

[email protected]

Abstract

Solenostemon rotundifolius, known in Ghana as Frafra potato, is vegetatively propagated and listed among endangered crops. Shoot tip and nodal explants for cryopreservation were

subjected to pre-cooling treatments with sucrose or mannitol supplemented medium, vented

culture vessels and forced sterile air to condition cultures. The ability of shoot tip and axillary bud explants to tolerate dehydration was higher in mannitol treated cultures. Explant survival

following dehydration over silica gel for 90 minutes was 54.63% for mannitol treated cultures at water content of 0.24 gg-1 dry wt and 19.72% for sucrose treated cultures at 0.36 gg-1 dry

wt, respectively. This was indicative of mannitol enhancing desiccation tolerance. Although the use of forced sterile air and vented culture vessels reduced explant water content, the

hyperhydric nature of cultures with initial water contents of 17-22 gg-1 dry wt made it very

difficult for explants to be conveniently dehydrated prior to cooling down to ultra-low temperatures. The Frafra potato explants were extremely sensitive to vitrification solution

used. This work shows the effect of the various treatments on cryopreserved explants using ultra structural investigation. Also, the extremely high initial water content of the mother

plant could be the underlying factor preventing successful cryopreservation.

Key words: Solenostemon rotundifolius, cryopreservation, dehydration, silica gel,

explants, vitrification, survival, ultrastructure, water content.



(ISTRC-AB)

201

How released sweetpotato varieties are distributed in Uganda and how perhaps

they should be

Richard Gibson

Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent,

ME4 4TB, UK. Email: [email protected]

Abstract

Released varieties of mainly orange-fleshed sweetpotato (OFSP) are mainly distributed in Uganda through a project-based seed system. In this, the planting material is multiplied and

supplied to projects by private enterprise institutions. The largest of these are based in the

North East of Uganda and are cooperatives derived from farmer groups, set up originally by projects mainly for training purposes; they had received the varieties from projects. Others

are individuals, most of who had hosted national Sweetpotato Program variety trials and so had obtained the released varieties. These institutions intermittently received orders from

projects for sometimes thousands of sacks of vines; these vines were then distributed free to benefitting households in the target areas of the project, usually by local non-government

organizations (NGOs). Sales to projects were lucrative but relatively uncertain. There were

also a few informal vine multipliers who had ‘accidentally’ obtained planting material of one or a few released varieties, often through their inclusion in a free distribution as a benefitting

household. These multipliers sold bundles of vines to farmers at the start of the rains; they did not sell into the project-based seed system. It is proposed that it would be better if projects

purposely provided informal vine multipliers with released varieties and then supported them to sell the vines (rather than give them) to smallholder farmers through their traditional seed

system. This would be self-sustaining whereas the project-based seed system which, though

providing free vines, provides them only for the duration of the project.

Keywords: Informal, vine multipliers, project-based seed system



(ISTRC-AB)

Seed Potato System in Nigeria: Status, Challenges and Prospects

*1Amadi, C. O., 2aLenka, D. M. and 2bDung, E. A.

* Email: [email protected]; 2a [email protected]; 2b [email protected]

1. Nat ional Root Crops Research Institute Umudike, PMB 7006, Umuahia, Abia State, Nigeria

2. Nat ional Root Crops Research Institute Umudike, Potato Programme Kuru, PMB 04, Vom, Jos,

Plateau State, Nigeria

Abstract

A seed system is an integrated set of components or activities including breeding, management, replacement and distribution of seed which ensures that planting materials are made available

for ware crop production. The seed potato demand in Nigeria is about 600,000 tons per annum. The seed potato system in Nigeria is largely informal with all the typical informal

features of integration, local organization, flexibility, and non regulation. Over 80% of the

potato seed is supplied by the informal sector. The quality of seed in the informal sector is poor resulting in low yields of about 5-7tons/ha compared to 15-25tons/ha from clean seed.

The future of seed potato system in Nigeria is bright. It is gradually evolving into a private sector driven formal enterprise with clear focus on seed production as distinct from ware

potato production. A seed multiplication scheme starting with importation, followed by one or two cycles of local multiplication before selling to farmers is ideal in order to reduce the price

of the seed to make it affordable to farmers. However, developing the local capacity to

produce clean seed that will be certified by a regulating company holds the key to a sustainable future for the seed potato system in Nigeria. Nigerian potato farmers saddled with the problem

of declining yield due to poor quality seed are likely to accept to pay a fair price for good quality seed that will boast there harvest.

Key words: Seed system, seed potato, clean seed, potato

202





(ISTRC-AB)

203

Working with community based organizations to promote consumption of orange

fleshed sweetpotatoes through on-farm participatory trials

Ssemakula Gorrettie 1, Mwanga Robert2, Ann-Marie Ball3, Kyalo Gerald2, and

Namakula Joweria1

1Nattional Crops Resources Research Institute, 2International Potato Center, 3Harvest Plus project

Abstract

Uganda has a high incidence of malnutrition especially Vitamin A Deficiency (VAD), this is exacerbated by the prevalence of HIV/AIDS. In an attempt to mitigate the situation, Orange

fleshed Sweetpotatoes (OFSP) are being promoted in five pilot districts of Buyende, Rakai, Isingiro, Kabale, and Oyam through farmer participatory on-farm trials. The initiative was

based on earlier positive impacts of OFSP interventions in other districts by HarvestPlus where it was reported that OFSP boosted immunity of HIV/AIDS orphaned children. The

National Crops Resources Research Institute (NaCRRI) is working with community based organizations (CBOs) in involving farmers to evaluate OFSP under farmer managed conditions,

coupled with training of the farmers in production and utilization of OFSP. The CBOs include

Community enterprises development organization (CEDO) in Rakai, Volunteer Efforts for Development Concerns (VEDCO) in Kamuli, Millenium Villages in Isingiro, Africa 2000

network in Kabale, and World Vision in Oyam. Ten willing farmers/farmer groups were selected in each of the districts by the CBOs to host the trials. Three new OFSP clones were

evaluated for yield, palatability, reaction to virus disease, Alternaria and weevils against one released OFSP (NASPOT 10 O) and a local check. Two clones, SPK 004 2006/1136 and

Naspot 7/2006/292 were consistently liked by farmers and are going to be released officially.


(ISTRC-AB)

204

Farmers’ methods of evaluating cassava varieties in tropical climatic conditions

of western Kenya

Vincent W. Woyengo1, 2, *, Rob Melis2, Paul Shanahan2, Omari M. Odongo3

* [email protected] 1Kenya Agricultural Research Institute (KARI), Kakamega, P.O. Box 169, Kakamega, Kenya. Tel.

+254 729981023, e-mail: [email protected] 2African Centre for Crop Improvement (ACCI), University o f KwaZulu-Natal, Private Bag X01,

Scottsville 3209, Pietermaritzburg, South Africa. E-mail: [email protected] and

[email protected] 3Kenya Agricultural Research Institute (KARI), Kitale, P. O. Box 450, Kitale, Kenya. E-mail:

[email protected]

Abstract

Successful participatory variety selection (PVS) depends on the effectiveness of the variety evaluation methods used. A study to determine the effectiveness of indigenous knowledge (IK) and scientific knowledge (SK) farmers and breeders respectively, use to select cassava

varieties. The study was carried out in three cassava growing districts purposefully selected

to represent different cassava production niches in western Kenya. The results showed significant differences between the cassava varieties when evaluated using both IK and SK

for all traits evaluated except cyanide content and culinary traits when evaluated by farmers and breeder respectively. Variety ranking by farmers from different districts and between

farmers and the breeder in all districts differed indicating differences in variety preferences by farmers from different districts and between farmers and the breeder. These results

mean both IK and SK were effective in cassava evaluation and can be deployed in cassava varieties evaluation. However, the inability to elicit genotypic differences between the varieties

in cyanide content using IK, culinary traits using SK and differences in variety ranking between

farmers and the scientist indicate the need for farmers-scientist collaboration in variety evaluation.

Key words: Farmer preferred traits, indigenous knowledge (IK), scientific knowledge (SK),

participatory plant breeding (PPB), participatory variety selection (PVS), variety ranking.








(ISTRC-AB)

205

1

Breeding cassava for enhanced â–carotene content for better nutrition: progress,

challenges and prospects from Uganda

Williams Esuma*, Robert Kawuki, Anthony Pariyo, Yona Baguma and Titus Alicai National Crops Resources Research Institute. P. O Box 7084, Kampala. www.nacrri.go.ug Tel:

+256 414 573016 * [email protected];

Abstract

The low nutritional composition of cassava (Manihot esculenta Cranz) has remained a major factor which underrates the crop as a complete food crop. Notably, vitamin A deficiency that ranges from night blindness to Xerophthalmia and Keratomalacia causing total blindness

has been noted as a serious health hazard in communities where cassava is a major stable.

Nonetheless, global efforts are being made towards nutrient enhancement in cassava, provitamin A-rich cassava becoming apparent. This initiative is strongly envisaged as a strategy

for sustainably addressing malnutrition associated with heavy dependence on cassava for nutrition. In Uganda, considerable breeding efforts have been made towards developing and

deploying â–carotene rich cassava varieties. Hybridisation of carotene-rich genotypes with farmer-preferred varieties resulted into F progeny with wide segregation for â–carotene

content (0.56 – 5.98 µ/g), dry matter content (18.4 – 42.3%) and agronomic properties. This

suggests an opportunity for developing carotene-rich cassava varieties through hybridization and selection, using the genetically adapted landraces. Therefore, we present the breeding

progress, challenges and prospects delivering provitamin A cassava varieties in Uganda.

Key words: Provitamin A, cassava breeding, nutrition.

http://www.nacrri.go.ug/



(ISTRC-AB)

206

Evaluation of introduced yam genotypes in three agro-ecologies of

Sierra Leone

P.E. Norman*1, J.B.A. Whyte **1, A.E. Samura1, A. Massaquoi3, L. Sesay3, A.G.O.

Dixon2, S.N. Fomba1, M.T. Benya1 and M.M. Sowa1

1Njala Agricultural Research Centre (NARC), Sierra Leone Agricultural Research Institute

(SLARI), PMB 540, Freetown, Sierra Leone; 2 SLARI, PMB 1313, Freetown, Sierra Leone;

3 Zonal Agricultural/Extension Officer, NARC, SLARI, Njala, Sierra Leone.

*[email protected]; ** IITA Consultant to SLARI/West Africa Agricultural Productivity

Programme ( WAAPP) at NARC, Njala, Sierra Leone; Regional Agricultural/Extension Officers,

NARC.

Abstract

Costs and lack of planting materials, labour, staking and inappropriate knowledge on production

techniques are major constraints of yam production in Sierra Leone. A total of nine promising hybrid genotypes of yams from International Institute of Tropical Agriculture (IITA) and one

local cultivar, Pulli, were evaluated for yield, reaction to local pest and disease and desirable market traits during 2011 and 2012 in three agro-ecological zones of Sierra Leone. The

experiment was laid out in randomized complete block replicated thrice at the experimental sites of the Njala Agricultural Research Centre (NARC). Results revealed higher disease

pressure in non-staked plots compared to staked plots. Fresh tuber yields were significantly

higher in staked plots than the non-staked plots. Similarly, yields were higher in 2012 than in 2011. Five genotypes with yields ranging between 11.9 and 14.8 tha-1 significantly out-yielded

Pulli (9.2 tha-1) in the staked plots, while only genotype TDa 02/00012 (11.8 tha-1) significantly out-yielded Pulli (7.1 tha-1) in the non-staked plots. Farmers’ preferences for all genotypes

were similar to that of the local cultivar. Staking contributed 31% mean yield increase compared to non-staking. Makeni had the highest percent mean yield increase due to staking (39.9%)

compared to Njala (31.0%) and Kenema (27.7%).

Key words: evaluation, yam genotypes, desired traits, agro-ecologies




(ISTRC-AB)

207

Root and tuber crops species conserved at Plant Resources Center: Potential

and Beyond for The Future in Vietnam

Nguyen Van Kien, Hoang Thi Nga, Nguyen Thi Hanh, Le Thi Hang, Le Van Tu,

Nguyen Phung Ha Plant Resources Center, Vietnam

[email protected]

Abstract

Root and tuber crops species (after here called R&T Crops) are known as crop species of marginal and disadvantageous areas and the poor in the world last several decades. Most of

them play key role in agriculture production system in developing countries and a key livelihood source of the poor. Recent scientific research has shown that R&T Crops contain biological

components/substrates that are good for the health and nutrients needs of people. Moreover, climate change, energy and food security circumstance, role of root and tuber crops species

have become more important than before. Thus, conservation and exploitation of R&T Crops germplasm are so necessary for meeting future demands as well as preserving the diversity

of agro-ecological system. At present, Plant Resources Center is maintaining 2,600 accessions

of more than 25 root and tuber crop species (sweet potato, cassava, taro, zinger, yam, edible canna,…). The collections were launched before 1996.The results of R&T Crops conservation

and use at Plant Resources Center will be reported in the conference for strengthening knowledge and promoting utilization of R&T Crops germplasm in term of the diversity,

characterization and documentation and especially introduction on promising R&T Crops germplasm of sweet potato, taro, yam and edible canna crops species at Plant Resources

Center of Vietnam.

Keywords: Marginal and disadvantageous, Key livelihood, Health and nutrients, Climatic

change



(ISTRC-AB)

208

Genetic characterization of exotic and landrace of cassava (Manihot esculenta

Crantz) in Ghana

K. Y. Karim1 , R. Akromah2* , J. A. Manu-Aduening3

1Sierra Leone Agricultural Research Institute, Njala Agricultural Research Center, Freetown

Sierra Leone. 2School of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

3Crops Research Institute, Kumasi-Ghana. *rakromah@yahoo)

Abstract

Cassava cultivars grown in Ghana are often misrepresented due to improper characterization of the genetic materials available. The genetic diversity of 45 accessions (selected as a core

of 150 cassava accessions) collected from Crops Research Institute of Ghana was assessed

and characterized using agro-morphological and molecular means. Both quantitative and qualitative traits such as plant height, angle at first branching, canopy spread, petiole length,

root yield, dry matter content, root shape, petiole colour, and pubescence on apical leaves were used to assess their variability for phenotypic characterization. Genomic DNA of the

accessions were extracted and used as template for Polymerase Chain Reaction (PCR) amplification involving nine Simple Sequence Repeat (SSR) markers. The recorded gel bands

as well as the agro-morphological traits were subjected to cluster analysis and development

of dendrogram to show the corresponding similarity coefficients. Agro-morphological characterization grouped 2 accessions into cluster A, whilst 43 accessions were grouped in

cluster B. Molecular characterization also grouped 16 accessions in cluster A and 29 in cluster B. Overall, both molecular and agro-morphological characteristics put 3 accessions

in cluster A and 42 in cluster B. The genotype identification showed that, the phenotypic characters have a similarity coefficient range of 0.80%-1.00% whilst the molecular also had

a wider coefficient range of 0.2-1.0%. These features showed the extent of diversity present

in the accession evaluated and served as a basis for efficient management and utilization of germplasm in breeding programme. Therefore, the application of morphological descriptors

in characterization of germplasm should be backed by the use of molecular markers.

Key words: Morphological charaterisation, duplicate accessions, Germplasm, molecular markers, genetic diversity, Polymerase Chain Reaction (PCR) and Simple Sequence

Repeat markers (SSR).

mailto:*rakromah@yahoo


(ISTRC-AB)

Landraces genes in cassava improvement

Mahungu N.M1., Bidiaka M1., Binzunga M.2, Nluta S.1, Ndombo N.1

1International Institute of Tropical Agriculture, IITA/DRC ([email protected];

[email protected]; [email protected]; [email protected] ) 2Institut National pour l’Etude et la Recherche Agronomiques ([email protected])

[email protected]

Abstract

The cassava landraces have some interesting genes by farmers, which would give best products (fufu, chikuangue, malemba, kabiola, Pondu), but mains of these varieties are in more of cases soft to diseases and pests, what induce the loss of root yield. This situation

associated with traditional system of production caused the risk of food insecurity to majority

of Congolese populations of whose cassava is the most important food crop. To crowd cassava a safety culture and to meet the populations’ needs, INERA since 1974 by its research

program had begun research for improvement by incorporating local varieties genes by crossings of parents with best farmers’ traits. The results of this advanced are palpable by

the development of some improved varieties resistant to diseases and pests and also having traits wished by framers and industrialists like: Mvuama, Rav, Sadisa and Lueki.

209











(ISTRC-AB)

210

Farmer Participatory Development of Four Sweetpotato Varieties in Ghana

K. Adofo¹*, J.N. Asafu-Agyei¹., J.N.L Lamptey¹, E. Carey², E. Baafi¹, E. Obeng-

Bio², E. Adu-Kwarteng¹, E. Owusu-Mensah², P. Acheampong¹, J. Haleegoah¹,

Victor Amankwaah¹, N. Asamoah-Obeng¹ and J. K Awoodzie¹ ¹CSIR-Crops Research Institute, P.O. Box 3785, Kumasi, Ghana;

* [email protected], +233208198214

² International Potato Centre (CIP), c/o P.O. Box 3785, Kumasi, Ghana

Abstract

Four elite sweetpotato clones were evaluated for adaptability and acceptability by morphological, molecular, agronomic, post-harvest and socio-economic assessment in 2009-

2012 to generate data for new varietal releases in response to farmer and consumers

preferences (high yielding, disease and pest resistant, nutritious and with better processing qualities) of the crop in Ghana. Farmer Participatory Approach (FPA) was used in Multi-

location Trials (On-station and On-farm) across the Coastal and Forest-Transition zones of Ghana. Trials were RCBD in 3 reps, 4 ridges per plot of 1m x 0.3m spacing. Fourteen Simple

Sequence Repeats markers were used to check diversity. Physico-chemical and Nutrient composition of these clones were also investigated. Results from the molecular characterisation

indicated low similarity coefficient among the new clones. The new varieties were found to be

differently adapted to the different agro-ecological zones. Very good results were obtained from the Physico-chemical and Nutrient Analysis of the clones while Sensory evaluation ratings showed

a high acceptability. Some outstanding attributes of the newly released sweetpotato varieties included, high yields (18 – 22 t/ha), high dry matter (31- 34 %), high starch content (68 – 69.5 %

mg/100g DW), Beta-carotene (2800 - 5500µg/100g), Total sugars (14.7 – 15.2 %) and appreciable levels of iron (1.27- 2.99 mg/100 DW) and zinc (0.96 – 1.69 mg/100g DW). The Cost Benefit

Ratios of adopting these new varieties across locations tested ranged from 3.94 to 5.66. These

clones were therefore proposed and released as varieties in 2012 in Ghana




(ISTRC-AB)

211

Genetic variability of six cassava traits across three locations in Ghana

Peprah Bright Boakye 1*, Agyeman Adelaide 1 and Elizabeth Yaa Parkes1,2

1Crops Research Institute, Fumesua, Kumasi, P. O. Box 3785, Ghana. 2International Institute of Tropical Agriculture, Ibadan, Nigeria.

[email protected]

Abstract

A study was conducted to assess the extent of genetic variability, broad-sense heritability and correlations for fresh root weight, root number, top weight, vigour, cassava mosaic disease

and cassava green mite of eight marker assisted selected cassava genotypes across three locations in 2 years in Ghana. Combined analysis of variance revealed highly significant

genotypic effect for all the traits except root number which was just significant. Genotype x environment interaction was also significant for root number, top weight, cassava mosaic

disease and vigour indicating considerable but, varying response of the genotypes to the environments. High broad-sense heritability values were observed for all the traits. High

broad- sense heritability and genetic advance as percent of the mean were observed for cassava mosaic disease, suggesting that the trait is primarily under genetic control and that a

simple recurrent phenotypic selection scheme would be rewarding. Phenotypic coefficients

of variation values were larger than their corresponding genotypic coefficient of variation values for all traits. Correlations between root number, root weight and top weight were

highly significant and positive indicating that simultaneous progress for the three traits is feasible.

Key words: Ghana, Manihot esculenta, cassava traits, genotypes.



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212

IITA Genebank: Sanitization and Distribution of Cassava Germplasm for breeding

and research

Jekayinoluwa T.A, Gueye Badara, Abberton Michael

Genetic Resources Center, IITA Ibadan

[email protected]

Abstract

An important way to support the growing human population is to conserve endangered crop diversity and develop more productive varieties with enhanced tolerance to environmental stresses. Plant genetic resources (PGR) provide raw materials that plant breeders, researchers

and farmers need to improve the quality and productivity of crops. PGR is a prerequisite to

meet the target of crop improvement, development and food security. It is the responsibility of genebanks to conserve this heritage and this can be greatly facilitated through collaboration

with breeders. The IITA Genetic Resources Centre (GRC) works closely with breeders and other researchers in the acquisition, characterization, evaluation, conservation, sanitation and

distribution of released varieties, inbred lines, international collaborative trials and other important stocks of cassava and yam. GRC has developed improved conservation systems

(medium and long term conservation) and postflask management. Cassava breeding material is cleaned through in vitro tools (thermo treatment and meristem regeneration), conserved

and distributed in a common effort between the GRC and the cassava breeding team. The

conservation and distribution to potential users is carried out after clean health status is confirmed by the IITA Germplasm Health Unit. In 2012, approximately 22% of available

improved and elite cassava germplasm was distributed to seven countries compared to 2% distributed in 2010. This is an indication of progressive use of root and tuber germplasm with

continued vision to support crop improvement.

Keywords: Sanitization, Conservation, Distribution, Cassava, Yam, Germplasm



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213

Advances in Cassava (Manihot esculenta) and Yam (Dioscorea spp.) Breeding and

Development in Sierra Leone: 2008-2012

S.N. Fomba*2, J. B.A. Whyte**2, F. B. Massaquoi2, P. E. Norman2, A.E. Samura2,

A.G.O. Dixon3, M.L.S. Gboku3, D. S. Fornah3, L. Sesay4, A. Massaquoi4 and F.

Kobba4. 2 Njala Agricultural Research Centre (NARC), Sierra Leone Agricultural Research Institute

(SLARI), PMB 540, Freetown, Sierra Leone; 3 SLARI, PMB 1313, Freetown, Sierra Leone;

4 Zonal Agricultural/Extension Officer, NARC, SLARI, Njala, Sierra Leone.

* Contact author; ** IITA Consultant to SLARI/West Africa Agricultural Productivity Programme

(WAAPP) at NARC, Njala, Sierra Leone; Regional Agricultural/Extension Officers, NARC.

Abstract

Cassava (Manihot esculenta Crantz) and Yam (Dioscorea spp.) are among the most

important root and tuber crops grown in Sierra Leone. Genetic improvement of these two crops is mainly through introduction of exotic germplasm from the International Institute of

Agricultural (IITA) at Ibadan, Nigeria and local collection; screening, selection and advancement of promising lines in a participatory manner with farmers and other stakeholders

in the crop development process. Breeding objectives of the above two crops are aimed at addressing the devastating problem of pests and diseases prevalent in Sierra Leone, cassava

mosaic disease (CMD),cassava bacterial blight (CBB), green mite, mealy bug and

grasshoppers; yam anthracnose, and viruses. In the recent past six SLICASS varieties of cassava with yield range of 25-35mt/ha were released to farmers but yam varieties are yet

to be released. Advances made in developing new and more nutrient-rich genotypes of cassava with yield range of 40-50 mt/ha are described. Similarly promising yam varieties in

the pipeline for release are also described, including some economics of their production under staked and non-staked conditions of growth.

Key words: Manihot esculenta, Dioscorea spp., Participatory varietal selection,

economic analysis


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214

Dry matter determinationin cassava - A better approach

P.O. Iluebbey, E.Y. Parkes, A. Agbona,O.O. Ainaand P.A. Kulakow

International Institute of Tropical Agriculture (IITA), Nigeria

[email protected]

Abstract

Improvement of dry matter content of Cassava (Manihot esculenta Crantz) has been a major research focus in IITA.Cassavais a source of calories for about 500million people who

largely rely on the dry matter content to translate to food on their table and money in their pockets.Hence the best method to determine dry mattercontent in cassava was investigated

at IITA using six cassava genotypes (two white-fleshed and four yellow-fleshed). The two

white-fleshed genotypes used were: IITA-TMS-IBA980505 and TMEB419 while the yellow- fleshed genotypes are: IITA-TMS-IBA011368, IITA-TMS-IBA011371, IITA-TMS-

IBA0111412 and IITA-TMS-IBA070593. Five roots from 12-month old plants were sampled per genotype. One whole root was shredded and thoroughly mixed to ensure it included the

distal, middle and proximal portions.100g fresh weight sample was taken from this. Other roots were divided into the distal, middle and proximal. One root was sampled for 5g distal,

middle and proximal. One other root was samples for 50g while one other was sampled for

100g. The fifth root was sampled for core portions of the different parts. This was repeated three times. Samples were oven dried at 700C and weighed after every 24hours until a

constant weight was obtained. Result showed that dry matter content differ between different portions of the root with the core portion of the root having the least dry matter.Using whole

shredded roots with fresh weight of more than 50g was found to give better dry matter accuracy.

Key words: Genotype, dry matter, sample, shredded roots



(ISTRC-AB)

215

Effect of varieties on the adsorption isotherm of yellow-fleshed cassava root

starches

Awoyale, W1., Sanni, L.O.2, Shittu, T. A2., Adegunwa, M.O3., Badara, G4

and Kulakow, P.4

1. Department of Food, Agriculture and Biological Engineering; Kwara State University

Malete, Kwara State, 2. Department of Food Science and Technology; Federal University of Agriculture Abeokuta,

Ogun State. 3 Department of Foodservice and Tourism; Federal University o f Agriculture Abeokuta,

Ogun State 4. International Institute of Tropical Agriculture, Ibadan, Oyo State

[email protected], [email protected]

Abstract

This research was used to predict storage stability of cassava starches for application in custard powder and for other food uses. Like most powdery products, yellow-fleshed cassava

root (YfCR) starches are hygroscopic and the storage conditions could affect its quality vis- à-vis its uses. YfCR starches were extracted from three genotypes TMS-I011371, TMS-

I011368 and TMS-I061630; dried using a cabinet dryer at 45±5 oC for 18 h and milled to fine powder after which the adsorption isotherms were determined by static gravimetric method

at temperatures of 27, 37 and 42 oC and water activities level of between 0.10 and 0.80. The starches were then placed in temperature-controlled cabinets for approximately 18 days and

data obtained fitted to four sorption models. The fit was evaluated using the coefficient of

determination (R2) and percentage deviation (% E). The result shows a type II sigmoidal shape, and the GAB and modified Oswin models (R2 < 90 % and %E < 10 %) gave the best

fit for modelling the adsorption isotherm of the starches. The monolayer moisture content (MLMC), taken as the safe minimum moisture level in the starches, was determined using

the GAB equation and was found to range between 6.64 and 8.75 g water/100 g solid. The MLMC was significantly (pd”0.05) higher in TMS-I061630 and lower in TMS-I011368

irrespective of the storage temperatures. This implies that TMS-I011368 starch could be stored for longer periods at all the temperatures and used for food applications in time of

scarcity.

Key words: Yellow-fleshed cassava starch, adsorption data, water activity and monolayer

moisture.





(ISTRC-AB)

216

New approaches for Root and Tuber genetic resources conservation and use

Gueye Badara and Abberton Michael

Genetic Resources Center (GRC), International Institute of Tropical Agriculture (IITA). PMB

5320, Oyo Road, Ibadan, Nigeria

Abstract

Cassava and yam play an important role in providing food security and income in sub-Saharan Africa. However, their production is still constrained by many factors such as scarcity of

planting material, pests and diseases. Therefore, the cultivation of cassava and yam needs more attention in term of genetic resources collection and their use to support crop improvement

programs. These are the prerequisites for the production, propagation and distribution of

quality planting materials for farmers, to ensure optimal yield. Thus, the existing root and tuber conservation and use system has to move to a new paradigm, with different approaches

involving genetic resources (GR) centres, breeders, germplasm health specialists, social scientists and farmers. The first focus should be in filling the cassava and yam genetic gaps

by more germplasm capture, including farmers’ knowledge. The value and utility for crop improvement of the collected genetic resources will be facilitated by high quality standards

and accessible documentation, with complete passport, characterization and evaluation data.

It is essential that GR information comes from a common activity of GR centres and breeding team. The cassava and yam GR can thus be useful for breeding and research. The usefulness

of cassava and yam collections is furthermore shown in the end user-oriented management via definition of core collections, trait-specific subsets and Focused Identification of Germplasm

Strategy (FIGS). The joint working approach between GR centres and breeding teams is also essential in pre-breeding activities including genotyping, phenotyping and genetic base

broadening. Since pest and diseases can be major constraints to germplasm exchange, more

involvement of virologists and plant pathologists is necessary for germplasm exchange. In summary, considering the challenges in releasing of root and tuber potential, it is essential to

have a holistic strategy for the conservation and use of cassava and yam GR, involving not only GR centres but also breeders and social scientists in order to reach the goal of ensuring

food security.


(ISTRC-AB)

217

Determination of Beta-Carotene Content of yellow root cassava

using iCheckTM Device

A.O. Ogungbesan, , E. Y. Parkes, N. A. Maroya, O.O.Aina, P. I. Iluebbey,

A.Agbona and P. A. Kulakow [email protected]; [email protected]; [email protected]; [email protected];

[email protected]; [email protected]; [email protected]

Abstract

Cassava (Manihot esculenta Crantz) is an important staple which contains a limited amount of Pro-vitamin A caroteniods. In order to find a solution to cost and reduce the time taken to

determine amount of carotenoids in cassava roots of large breeding populations, such as

seedling nursery and clonal evalution trials, IITA cassava breeding unit has employed the use of iCheckTM device. This is a portable digital photometer for determining the carotenoid

levels in samples that can also be applied for assessment of carotenoids in cassava. iCheckTM

was used to analyse root samples of yellow fleshed cassava from 35 genotypes at the seedling

nursery evaluated in 2011/2012 and 35 genotypes at the clonal evaluation (2012/2013) trial. Results showed correlation (r = 0.60) between the seedlings and their clonal counterpart.

Analysis using icheck device showed a reduction in cost compared with other forms of

analysis such as HPLC (high pressure liquid chromatography) and spectrophotometry which are more expensive, time consuming and require extensive training. The iCheckTM device

proves to be useful for quick screening of large populations of cassava genotypes with potential use in breeding. The device comes handy, can easily be used outside the laboratory enviroment

such as field stations with limited facilities and electricity.

Key words: betacarotene; iCheckTM; sample; photometer










(ISTRC-AB)

218

On farm participatory evaluation of improved cassava genotypes (manihot

esculenta Crantz) in Sierra Leone

F.B.Massaquoi, A. E. Samura, A. Mansaray, D. D. Quee, D. S. Fornah, L. Sesay,

A. Massaquoi, M. T. Benya and S. N. Fomba

Njala Agricultural Research Centre (NARC)

Abstract

In Sierra Leone, cassava is the second most important staple crop after rice. It is cultivated nationwide and constitutes a significant portion of the diet of the rural population. The crop is

grown by smallholders in mixed cropping with many other crops, and of lately also in sole crop stands. It is becoming an important cash crop for smallholder farmers. However, farmers

have not had the opportunity to test crop genotypes from most breeding programmes and have resulted in low adoption of varieties developed over the years; hence the continual use

of traditional cultivars that are less productive and susceptible to diseases and pests. To mitigate this, farmers are now being involved in the testing of improved genotypes along side

their local cultivars. This has proven to save time and ensured careful selection of improved

genotypes leading to high adoption by local farmers. The objectives were to determine the performance of improved cassava varieties on farmers’ fields,evaluate genotype responses

to prevailing diseases and pests, determine farmers perception about the improved planting materials viz – a – viz the general performance and growth rate and yield. Challenges and

constraints faced by farmers during the crops’ growth were also determined. Against this background, eighteen (18) improved cassava genotypes and preferred local cultivars were

evaluated in ten districts across four agro-ecological zones nationwide. The study results

showed that farmers have definite requirements for genotypes they select. These requirements ranged from agronomic to food and quality characteristics. It is also noted that farmers can

conveniently partner with scientists to develop genotypes of food crops. Pests and diseases pressure were generally low (Score 1 – 2 for all genotypes evaluated across locations except

the local cultivar, cocoa). The environments in Kenema in the East, Kambia in the North and the Southern Districts are the most promising environment for cassava productivity. Finally,

genotypes 97/ 4407 (06 ), 97/5512 (13) and yellow root (YR)-01 amongst others shows

promise. Key words: Local cultivars, improved genotypes, environment, farmers’ fields, performance


(ISTRC-AB)

219

Speed breeding and variety release for orange fleshed sweetpotato cultivar

diveristy in Malawi

FP Chipungu1, T Mkandawire 2, M Chitete 1 IR Benesi2, P Pamkomera3, O

Mwenye 1, EP Abidin4, M Andrade 5, W Gruneberg6 and M Chiipanthenga7

1Bvumbwe Agricultural Research Station, PO Box 5748, Limbe; [email protected]; 2Chetedze Research Station, PO Box 258, Lilongwe; 3Makoka Research Station, P/Bag 1,

Thondwe, Zomba; 4International Potato Centre, Blantyre, Malawi; 5International Potato Centre,

Maputo, Mozambique; 6International Potato Centre, Lima, Peru; 7Kasinthula Research Station,

Chikhwawa, Malawi

Abstract

Sweetpotato (Ipomea batatas (L) Lam) is one of the important food security crops in Malawi and Sub-Saharan Africa where vitamin A deficiency remains a problem especially in

children. Variety development for improved yields and beta-carotene source therefore provides the basis for a sustainable approach to food and nutrition security. Four sweetpotato genotypes

generated from open pollinated true seeds at Lunyangwa (LU06 codes) in 2006 and one at Bvumbwe in 2007 (BVU07/028 from Ejumula family) Research Stations were subjected to

speed evaluation in 2009/10 and 2010/11 seasons in multilocation trials at on-station and on- farm sites that represented different agro-ecological zones of Malawi. The genotypes were

evaluated for high root yield per unit area and time, resistance/tolerance to major pests and diseases, beta carotene content, organoleptic acceptability, crisp processing suitability and

post harvest shelf life. Two checks, Kenya and Zondeni were used in the evaluation. The

yield results of the testing genotypes, LU06/0252 (21.37t/ha), LU06/0428 (19.30), LU06/ 0146 (18.43t/ha) and LU06/0527 (17.09t/ha) revealed superiority but not significantly different

(P<0.05) from those of variety Kenya (16.21t/ha) the best yielding check. These testing genotypes were all preferred by consumers in terms of texture, flavour and general appearance.

The genotypes were also selected for their tolerance to sweetpotato virus and weevil damage at five months after planting. Under storage evaluation, LU06/252 stored for six months

after harvesting without rotting. Zondeni, a local variety with unstable yields was the only

orange fleshed sweetpotato under promotion for production in Malawi. Speed breeding was therefore eminent to provide variety diversity.

Key words: yield improvement, beta-carotene, storage, food, nutrition, economic growth



(ISTRC-AB)

220

Genetic evaluation of potato genotypes for agronomic, tuber quality traits and

resistance to late blight in Jos Plateau, Nigeria.

1Danbaba, A.K., 1Lenka, D.M., 1Haruna, A.O., 1Ruth Damara and 2Mamud, M.B.

1Potato Programme, National Root Crops Research Institute, M.B., 04, Vom,

Plateau State, Nigeria

2Federal College of Horticulture, Dadin Kowa, Gombe State.

E-mail: [email protected]

Abstract

Potato (solanum tuberosum L.) is a major tuber crop that has been grown on the Jos Plateau for a long time. It is considered as a cash and also a food crop. Potato yield and tuber quality

potentials has not been exploited in Jos Plateau. Thirty (30) divergent genotypes were evaluated for agronomic traits along with resistance to late blight (phytophthora infestans) in a

Randomised Complete Block Design replicated three times. A high Coefficient of Variability (CV) was observed for Area Under Disease Progress Curve (AUDPC) or late blight

resistance, moderate for days to maturity and low for marketable tuber weight. A high estimate of heritability and genetic gain was recorded for late blight resistance, days to maturity and

fresh tuber weight per plant. Cultivars 387300.125, WC 732 – 2, 392288.044, Ruslin Ruaka

and 393371.58 have moderate resistance to late blight. Coeffiecient of variability for specific gravity and dry matter percentage were moderate genetic gain was recorded for dry matter

percentage and days to maturity. The present study has helped in constituting and elite of potato genotypes for developing superior varieties with resistance to late blight and high dry

matter percentage which may comprise genotypes such as 387300.125, WC732 – 2, 396934.103 and 395096.2.

Key Words: Genotypes, heritability, genetic gain, coefficient of variability.



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221

1

Breeding cassava for enhanced â–carotene content for better nutrition: progress,

challenges and prospects from Uganda

Williams Esuma*, Robert Kawuki, Anthony Pariyo, Yona Baguma and Titus Alicai

National Crops Resources Research Institute. P. O Box 7084, Kampala. www.nacrri.go.ug

Tel: +256 414 573016 *Email: [email protected] ; *Cell phone: +256 782 071148

Abstract

The low nutritional composition of cassava (Manihot esculenta Cranz) has remained a major factor which underrates the crop as a complete food crop. Notably, vitamin A deficiency

that ranges from night blindness to Xerophthalmia and Keratomalacia causing total blindness

has been noted as a serious health hazard in communities where cassava is a major stable. Nonetheless, global efforts are being made towards nutrient enhancement in cassava,

provitamin A-rich cassava becoming apparent. This initiative is strongly envisaged as a strategy for sustainably addressing malnutrition associated with heavy dependence on cassava for

nutrition. In Uganda, considerable breeding efforts have been made towards developing and deploying â–carotene rich cassava varieties. Hybridisation of carotene-rich genotypes with

farmer-preferred varieties resulted into F progeny with wide segregation for â–carotene

content (0.56 – 5.98 µ/g), dry matter content (18.4 – 42.3%) and agronomic properties. This suggests an opportunity for developing carotene-rich cassava varieties through hybridization

and selection, using the genetically adapted landraces. Therefore, we present the breeding progress, challenges and prospects delivering provitamin A cassava varieties in Uganda.

Key words: Provitamin A, cassava breeding, nutrition.

http://www.nacrri.go.ug/




(ISTRC-AB)

222

Farmer Participatory On-farm Evaluation of Yellow to Orange-fleshed

Sweetpotato Accessions in Sweetpotato Based Cropping System of North Central

Zone of Nigeria

Njoku, J. C.*Afuape S., Nwankwo, I. I.M, Echendu, T.N.C. and E. Carey,

National Root Crops Research Institute, Umudike Umuahia Abia State

* [email protected]

Abstract Recent developments in release of new varieties suggest the involvement of farmers in the

breeding process to avoid mismatch of what the researchers and farmers (end users) consider as the best variety. In Nigeria white to cream colour fleshed sweetpotato predominate and

the introduction of orange-fleshed sweetpotato with high â-carotene a precursor for provitamin A will improve the nutritional wellbeing of rural community. Farmer participatory on-

farm trials were conducted in 2012 with 28 farmers in four states of North central zone of the country. The states are Benue, Nasarawa/FCT Abuja, Kaduna and Kwara. Six genotypes

including 3 orange fleshed types (CIP440293, NRSP/05/022and CIP199004-2), yellow fleshed

(Butter milk, , Ex-Igbariam) and one farmers’ best cultivar were evaluated. The evaluation involved researchers, Extensionist and Farmers. The genotypes CIP 440293 and NRSP/05/

022 with orange flesh significantly produced higher yields (19.7 and 17.8 t/ha) and were considered stable than other genotypes.In most cases, farmers’ assessment revealed that

genotype CIP199004-2was less preferred compared to the farmer’s best and other genotypes. Both male and female farmers in Kwara State, preferred CIP 440293 in terms of colour and

test. Generally farmers preferred genotypes based on good establishment, disease resistant,

good yield and skin and flesh colour.

Key words: Farmer, On-farm, Orange-fleshed sweetpotato, Accessions, Cropping systems, Nigeria



(ISTRC-AB)

223

1

1

Introgression of Cassava Mosaic Disease resistance into farmer preferred

cassava genotypes in Ghana

Elizabeth Yaa Parkes1, 5, Martin Fregene 2, Alfred Dixon3, Emmanuel Okogbenin4,

Bright Boakye Peprah5, Marian Dorcas Quain5, Samuel Kwame Offei6, Eric.

Danquah6, Maryke Labuschagne 7

1International Institute of Tropical Agriculture, PMB 5320, Oyo Road, Ibadan, Nigeria 2 Ministry of Agricultural, Abuja, Nigeria/ Donald Danforth Plant Science Center, St. Louis,

Missouri 63132, USA. 3 Sierra Leone Agriculture Research Institute, Sierra Leone

4 National Root Crop Research Institute Umuahia, Umudike, Abia State. Nigeria 5 CSIR-Crops Research Institute, Fumesua, Kumasi, Ghana

6 University of Ghana, Legon 7Dept of Plant Sciences, University of the Free State, P.O. Box 339, Bloemfontein9300, South

Africa.

[email protected]

Abstract

Cassava is a major staple and food security crop in Africa. It produces large amounts of

energy per unit land area under uncertain rainfall and low fertility conditions compared to other crops. However, it suffers from several pests and diseases. The CMD2 resistance

gene is being deployed in Africa for breeding in national programmes. A total of eight CMD resistant genotypes from CIAT were selected and used for crosses with three cassava

landraces and one IITA breeding genotype. CMD evaluation was done on the 12 parental genotypes and 525 F progenies comprising of individuals pre-selected for CMD resistance

based on average severity scores of 1 and 2. Multiple marker analysis was used to screen

for the CMD2 gene. Of the tested genotypes 83% showed at least one marker allele for the CMD2 gene. Two CIAT genotypes (CR52A-31 and AR14-10) had all four marker alleles

associated with CMD2. Only two of the local progenitors (Dabodabo and TME11) were resistant. TME11 had three alleles (RME-1, 158, 169) associated with CMD2 while Dabodabo

had one marker allele (SSRY28) associated with the gene. This suggests that Dababo may have alternative genes than CMD2 for CMD resistance. The F families showed segregation

for the CMD2 gene. A total of 88 individuals (17%) had the four marker alleles associated

with the CMD2 gene. A total of 179 individuals had between one to three marker alleles each associated with CMD2. A total of 91 individuals had no marker allele associated with the

CMD2 gene.

Keywords: cassava, CMD, landraces, marker assisted selection



(ISTRC-AB)

224

Evaluation of performance of introduced yam Bean (Pachyrhizus spp.) in three

Agro-ecological zones of Rwanda

J. Ndirigwe*1, Musabyimungu1 A., E. G. Kayinamura2, Tukamuhabwa3 P., W.

Gruneberg4 and P. Ndayemeye 1

1Rwanda Agriculture Board, Roots and Tubers Programme, P.O. Box 7231, Kigali,

Rwanda. 2Internship student, National University of Rwanda, Faculty of Agriculture, P.O. Box: 56

Huye RWANDA 3 Makerere University, Kampala, Uganda

4 International Potato Center, Lima, Peru.

[email protected]

Abstract The food insecurity in Rwanda has been attributed to the decreasing productivity of major root which are potato, cassava and sweetpotato and the lack of alternative crops such as

yam bean. Root and tubers crops are key staple crops for more than nine million people living in densely populated areas growing various crops for subsistence. Yam bean (Pachyrizhus

spp) has recently been introduced as a high-yielding root crop with high sugar content, considerable micro-nutrient concentrations and protein content for evaluation in three agro-

ecological zones of Rwanda where farming conditions are characterized by bimodal tropic rainfall and intensively cultivated fields. Field experiments with nine accessions were carried

out in 2012 at three different research stations sites in Rwanda. Strict reproductive pruning

to enhance fresh storage root was applied. Higher storage roots yield ranged from 43.00 to 3.74 ton/ha with accession 209018 Erosus genotype as high yielding (43.00 t/ha) and 209034

the lower yielding bush type, respectively. Results on crude protein showed that there were no significant differences between locations for protein content in tubers of yam bean

accessions but among the yam bean accessions there were a wide variation with the highest protein content of 22 % (209036). Harvest Index (HI) and storage root dry matter content

was significantly higher in P. Ahipa than in P. erosus. Accessions of P. erosus were more

resistant to nematodes and fungal attacks than those of P. ahipa in particular with the variety 209018 which is most resistant to the insect pest attacks.

Key words: Yam bean, Pruning, High Storage yield roots, Protein, Dry matter, Rwanda




(ISTRC-AB)

225

Genotype by Environment Interaction and Productivity of New Generation

Cassava Genotypes Developed for Food and Industrial Uses in Nigeria

P. A. Kulakow1, O. O. Aina1, E. Y. Parkes1, M.Yomeni2, J. Onyeka3, C. N. Egesi3,

B.Olasanmi3, P. Iluebbey1, A. Agbona1, A. G. O Dixon4

1 International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, [email protected],

[email protected], [email protected], [email protected], a. [email protected] 2 International Institute of Tropical Agriculture (IITA), SARD-SC, DR Congo,

[email protected] 3National Root Crops Research Institute, (NRCRI), Umudike, Nigeria, [email protected],

[email protected], [email protected] 4 Sierra Leone Agriculture Research Institute (SLARI), [email protected]

Abstract

Cassava (Manihot esculenta Crantz) is one of the most important food crops in sub-Saharan Africa supporting over 300 million people with various uses ranging from numerous food forms, to diverse industrial uses. However, regardless of the target use for any cassava

genotype, high yield and yield stability across agro-ecologies is always an important

consideration. This study examined genotype by environment interaction (GEI), and yield stability of 40 new generation cassava genotypes across 14 environments in Nigeria using

AMMI, GGE and the modified rank-sum method.The experimental design was a randomized complete block design (RCBD) in four replicates. Plot size was 6m x 6m at spacing of 1m

x 1m. Forty elite cassava genotypes were evaluated in two sets called ICT1 and ICT2 alongside three checks. Analysis of variance and AMMI analysis revealed highly significant

GEI among genotypes. Parameters evaluated showed significant correlations with each other.

GGE biplot identified three distinctive environment clusters. Two environments (Mokwa 2007- 08 and Mokwa 2008-09) were identified as the most discriminating environments for dry

yield. The modified rank-sum method identified 22 genotypes that performed better than the most adapted landrace (TMEB419) and 27 genotypes that performed better than the improved

check (IITA-TMS-IBA30572). Identifying cassava genotypes with high and stable yield and suitable for each environment contribute to optimising genetic potential of cassava for food

and other end user preferences.

Key words: genotype by environment interaction, cassava, AMMI, GGE biplot, modified

rank-sum method, clusters












(ISTRC-AB)

1

1

Genetic analyses of cassava segregating families for heritability and genetic gain

of carotene content and other agronomic traits by parent-offspring regression

Njoku1,2, D.N., Gracen2, V.E., Offei2, S. K., Asante 2, I. K., Egesi1, C. N. and

Kulakow 3, P.

1National Root Crops Research Institute (NRCRI), Umudike, PMB 7006, Umuahia.

2University of Ghana, Legon, LG 36.

3International Institute of Tropical Agricultural (IITA)

([email protected])

Abstract

Six cassava cultivars, three of high pro-vitamin A and three high dry matter content were crossed in a 3 x 3 topcross mating design to generate nine F populations. One thousand, one

hundred and ten (1, 110) botanical seeds from the 9 populations were sown in pots and maintained for 42 days in the screen house. The emerged (25cm) seedlings were hardened

and transplanted to the field on 30 April, 2010 alongside their parents, family by family. Four hundred and sixty four progenies survived and were harvested. Both field and laboratory

data were used to evaluate total carotene content (TCC), dry matter content (DMC), storage fresh root yield (SFRY) and other root qualities. Genotypic variation in DMC, TCC, SFRY,

biomass, root number, harvest index (HI) and dry root yield were recorded in all the families.

Narrow sense heritability by mid parent-offspring regression analysis and genetic gain were estimated for carotene content, dry matter content, storage fresh root yield and cassava

mosaic disease. Carotene content, dry matter content and cassava mosaic disease gave high heritability estimate of 0.73, 0.83 and 0.84, respectively. The correlation study showed that

TCC had negative correlation with DMC across all evaluation stages and locations. There were very high levels of variation in the segregating F progenies for all the traits.

Keywords: pro-vitamin A, heritability, genetic gain, correlation, cassava.

226



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227

Farmer Participatory Development of Cocoyam (Xanthosoma sagittifolium, Linn,

Schott) cultivars

E.L. Omenyo, M.D. Quain, E. Moses, H. Asumadu, P.P. Acheampong, and A. A.

Ankoma CSIR- Crops Research Institute, P.O.Box 3785, Kumasi – Ghana

Corresponding author’s e-mail, [email protected]

Abstract

Four years on station and on Farm evaluation of eight elite clones of Cocoyam were carried

out at four notable Cocoyam growing areas in the Forest Agro ecological zones of Ghana during the 2008/2009-2011/2012 growing seasons. This evaluation was conducted to identify

clones which are higher yielding and tolerant to major cocoyam diseases to be released as varieties to mitigate the declining productivity of cocoyam in Ghana. Parameters evaluated

were cormel yield and Incidence of diseases. Sensory evaluation, proximate nutrient content

and cost benefit analysis across locations were also carried out. Thirteen random primers were also used for molecular diversity study. Yields were all significantly different at all

locations for the four years. Clones showed no symptoms to moderate symptoms to major cocoyam diseases. Stakeholders rated in order of preference colour of skin/flesh, taste and

size of cormels as key determinants of a good cocoyam. Four of the clones (3 purple and 1 white) were identified as having higher yields, tolerant to disease and good cooking/eating

properties have been released as varieties. The molecular diversity studies grouped the

cultivars into two groups and this corresponded with morphological characteristics. Based on the cost benefit analysis a farmer is always better off in adopting any of the released varieties

in any of the locations where the evaluation were undertaken. Key words: Cocoyam, Xanthosoma sagittifolium, genetic diversity, cost benefit analysis,

random primers



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228

Development of Cryobanking for Long term Ex-situ conservation of cassava

AdeyemiAbigael O.*, Dumet Dominique*, Gueye Badara, Abberton Michael

Genetic Resources Center, PMB 5320, Oyo road, IITA, Ibadan, Oyo state, Nigeria.

[email protected] , [email protected] , [email protected]

Abstract

As technology develops and new ideas emerge, conservation of genetic diversity is gaining more advanced methods for increased efficiency. The technology of ex situ conservation of root and tuber genetic diversity follows this trend, through in vitro medium term conservation

and cryopreservation. The use of cryogenic methods shows considerable promise for the

long term conservation of cassava (Manihot esculenta Crantz). The droplet vitrification approach of cryopreservation, is gaining ground as a means of long term conservation, a key

component of a reliable ex-situ conservation strategy for cassava as a major clonally propagated crops.At the Genetic Resources Centre (GRC), IITA, cryopreservation via droplet

vitrification was tested on meristems excised from 48 in vitro cassava accessions. The survival of the post –cryopreservation was observed after four weeks. Survival rate was up

to an average of 96% after thawing out of which 86% regenerated to shoot and plantlets. It

was observed that the regeneration rate varies depending on the genotype. The relatively high success of the re-growth rate of the cryopreserved cassava genotypes gives hope for

the rationalization of in vitro conservation (labour, space and cost reduction) for such clonal crops. Also, the use of cryopreservation gives the opportunity of pathogen elimination

(cryotherapy) for germplasm sanitation purposes.






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229

Genetic variation of yellow-root cassava clones for high yields and earliness in

the guinea savanna ecology of Ghana

Kwabena Acheremu1, Joseph Adjebeng-Danquah1 and Emmanuel B. Chamba1

1 CSIR-Savannah Agricultural Research Institute

P. O. BOX 52, Tamale, Ghana

[email protected]

Abstract Cassava plays an important and major role in food security and poverty reduction. There is a growing need to select early bulking cassava varieties that are rich in vitamin A to resolve the

problem of vitamin A deficiency and also suit the system of keeping animals in the Northern

communities of Ghana as a whole. Seven (7) high beta (â) carotene cassava genotypes (01/ 1181, 01/1206, 01/1404, 01/1412, 01/1417, 01/1635 and01/1662) together with a local check

(Biabasse) were evaluated for the best early bulking (harvested at 6 and 9 months after planting) genotype and to select for high yield and dry matter content.The initial results

indicated that genotype 01/1206 recorded the highest root tuber yield of 19.03 t/ha at 6 MAP, and 25.03 t/ha at 9 MAP.Clone 01/1662 recorded the highest (45.58%) dry matter (DM)content

at 6 MAP and a significantly similarDM (38.62%) as that of the local check (39.47 %)

variety, Biabasse which was the highest at 9 MAP.01/1404 also recorded the highest (12) number of root tubers per plant at 6 MAP, reducing to 8 root tubers at 9 MAP, which is not

significantly different from that of the Biabasse (10) at the 9 MAP.This same genotype recorded the highest overall harvest index (HI) of 0.67 which was significantly higher than

the local check.The study showed that genotype 01/1206, 01/1404 and 01/1412 were, respectively, high yielding among the 7 tested genotypes as they showed early and high

yielding potential than the check (Biabasse).

Key words: cassava, food security, early bulking, vitamin A, beta (â) carotene, poverty

reduction,



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230

Progress made at improving farmer-preferred cassava landraces in Ghana

Manu-Aduening, J. A*., Peprah, B. B., Lotsu, E and Ohene, O.

CSIR-Crops Research Institute, P. O. Box 3785, Kumasi, Ghana.

*[email protected]

Abstract

Adoption of improved cassava varieties developed through conventional breeding by Ghanaian farmers has been low (<30%). This is worrying considering the amount of support provided

for research and dissemination of research outputs. Various reasons including non-poundability of improved varieties, limited knowledge on differentia l uses of such cultivars and

misconception that improved varieties are not edible, have been assigned to the low adoption

of improved varieties. Farmers thus continue to use their preferred landraces which are mostly low yielding due to their susceptibility to the African Cassava Mosaic Disease. A

strategy was developed in 2007 by the cassava improvement programme at CSIR-Crops Research Institute, Ghana to collect and improve selected landraces through genetic

hybridization, Marker Assisted Selection and participatory evaluation with different stakeholders. Advances made at improving the yields, pests and diseases resistance and

acceptance by different stakeholders are described. 10 promising lines with yields ranging

between 35–55T/ha, resistant to the African Cassava Mosaic disease and showing differential uses are being prepared for official release as improved farmer-preferred varieties for

Ghanaian farmers. Sensitization of farmers and other stakeholders on the attributes of these cultivars has started and it is anticipated that adoption will be high. The processes adopted

ensured maximum use of resources and techniques which resulted in shortening of the duration required (from 8-12 years to 3-5 years) for developing and release of varieties for production

by farmers. This is very significant considering the long gestation period for a crop like

cassava and the need for improved landraces by farmers.

Key words: African Cassava Mosaic, Marker Assisted Selection, genetic hybridization, participatory evaluation, cassava landraces



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231

On-farm assessment of field and culinary attributes of selected sweetpotato

genotypes by farmers for varietal nomination and release

Afuape, S.O., Nwankwo, I.I.M., Njoku, J.C. and Echendu, T.N.C.

Sweetpotato Programme, National Root Crops Research Institute, Umudike, Nigeria

[email protected]

Abstract

On-farm evaluation of advanced sweetpotato genotypes is one way to get farmers involved in the selection of desirable genotypes for varietal release. In a bid to select farmer-acceptable genotypes for release, eight advanced genotypes and one farmer cultivar were evaluated for

fresh root yield (t/ha) in on-farm trials in seven states. At the Abia state location, 12 male and

20 female sweetpotato farmers were further invited to assess the genotypes for field and culinary attributes. Across the seven locations, CIP 440293 ranked first with mean root yield

of 31.23 t/ha, followed by NRSP/05/022 with mean yield of 28.60 t/ha. For the assessment of field attributes of the genotypes, farmers, both males and females, rated the genotypes same

way for its planting material (vine), accepting NRSP/05/022, NRSP/05/10D and TIS 87/ 0087 and rejecting CIP 440293. Both sexes also had same preference for yielding ability as

bothsexes selected CIP 440293, NRSP/05/022 and TIS 87/0087 for high yield. Most farmersdid not show any special likeness for skin colour type.However, for flesh colour, strong preferences

were shown for the deep orange of CIP 440293 and the pure white of NRSP/05/10D. Overall,

genotypes CIP 40293 (66.4%), NRSP/05/022 (79.0%) and NRSP/05/10D (85.0%) were selected. On the assessment of the genotypes for culinary attributes, the appearance of

cooked roots of CIP 440293, NRSP/05/022 and NRSP/05/10D were well accepted. For taste, NRSP/05/10D was most preferred, while all the farmers preferred the texture of

NRSP/05/022 and NRSP/05/10D to other genotypes. In their overall acceptability rating, both male and female farmers showed strong preference of 100.0% for NRSP/05/10D,

followed by 97.5% acceptability for NRSP/05/022 and 76.8% acceptability for the orange-

fleshed CIP 440293. These three advanced lines which both male and female farmers mostly preferred will be nominated for official varietal release.



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232

Intra and inter-seasonal variability of cassava genotypes for plant morphological traits associated with resistance to green mite Mononychellustanajoa (Bondar)

(Acari: Tetranychidae)

Chalwe, A1., R. Melis2, P. Shanahan2, and M. Chiona1

1Zambia Agriculture Research Institute, Mutanda Research Station,

P.O. Box 110312, Solwezi, Zambia. 2African Centre for Crop Improvement, University of Kwazulu-Natal,

Pietermaritzburg, Private Bag X01, Scottville, 3200

[email protected]

Abstract

Cassava genotypes that combine earliness with prolonged underground storability are most preferred for food security under subsistence farming. However, the long growth cycle of

cassava coupled with the delayed harvesting by local farmers in Zambia exposes the crop to cassava green mite (CGM) attack which contributes to instability in yield performances of

cassava. Various plant morphological traits have been recognized as direct or indirect defence mechanisms that enhance host plant resistance (HPR) to CGM. However, little research has

been done to understand the stability of such traits despite their potential impact on the durability of HPR. With this background, field trials, involving sequential harvesting of cassava

at 9, 12, and 15 months after planting (MAP) were conducted for three seasons. The objectives

of the study were to establish the intra-season and inter-season stability of genotypes for resistance to CGM, and to understand the optimal bulking period of different cassava genotypes

in order to identify early-bulking CGM-resistant genotypes, as well as to identify clones with good underground storability. The genotype stability index was computed for each genotype

for CGM population density and leaf damage, fresh storage root yield and storage root dry mass percentage (SRDM%), storage root rot (SRR), and plant shoot morphological traits

related to CGM resistance, across sampling dates and seasons. Mweru and L9.304/175

exhibited high intra-season and inter-season stability for low incidence of SRR combined with high SRDM%. Genotypes L9.304/147, L9.304/175, 4(2)1425, I60/42 exhibited the highest

levels of intra-season and inter-season stability for high CGM resistance.



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233

Building collaborations to enhance research on an important but neglected crop, Taro (Colocasia esculenta)

Joseph Onyeka1, Badara Gueye 2, Robert Asiedu2, Leke Walter Nkeabeng2,3 and

Michael T. Abberton2*

1National Root Crops Research Institute, Umudike, Nigeria 2 IITA, Ibadan, Nigeria

3Institute of Agricultural Research for Development (IRAD), Cameroon

*Genetic Resources Centre, IITA, Ibadan, Nigeria. M. [email protected]

Abstract

Taro (Colocasia esculenta), also known in West Africa (particularly Nigeria, Ghana and Anglophone Cameroon) as cocoyam, is a perennial tropical crop primarily grown for its

edible starchy corm but also used as a leafy vegetable. It is native to Southeast Asia but is

now a staple crop in many parts of West Africa, Oceania and Asia. It has been estimated that about 10% of the world’s population uses taro or taro-like plants (Araceae) as a staple

in the diet. Despite this importance, the current level of research investment in this crop is very low.

There appears to be very few scientists conducting research on taro, and most often, these few scientists are not properly coordinated or equipped to make drastic change. A major set

back towards improving taro for a change is the narrow genetic base available in few isolated

institutions conducting research on the crop. There is a need to increase awareness of this crop and to build collaborations to address its research needs. This is particularly urgent

given the threat of taro leaf blight caused by Phytophthora colocasiae Raciborski, the most important disease of taro globally, which is now emerging in West Africa. Widening the

genetic base of current breeding programmes is an essential component of any research strategy to be developed and this requires collection of germplasm in West Africa.



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234

Mining for resistant genes in African cassava landraces to cassava bacterial

blight for deployment in breeding

Egesi C.N1*., Onyeka T. J1, Parkes E2., Peprah B2., Ezeji L1., Ijeh I3. and

Okogbenin E1

1 National Root Crops Research Institute (NRCRI) Umudike, Nigeria. 2 Crop Research Institute (CRI), Kumasi, Ghana

3 Michael Okpara University of Agriculture, Umudike, Nigeria

[email protected]

Abstract

Cassava Bacterial Blight (CBB) is an important resurging constraint to cassava production in the sub-Saharan. The disease is better managed by developing resistant cultivars which

depend mainly on availability of resistant genes. Many African cassava landraces constitute a repository of adapted genes for several useful traits. Although, these genotypes are often

poor yielding due to inherent genetic limitations, their useful genes for other traits can be characterized and harnessed through breeding for development of new varieties. We evaluated

a total of 256 accession in Nigeria and 225 accessions in Ghana under field conditions for novel sources of CBB resistant. Among the 256 accessions evaluated in Nigeria, a total of 59

(23%) were resistant to CBB. Majority of the accession (74%) were moderately susceptible

while approximately 3% were highly susceptible. Out of the 224 genotypes evaluated for CBB reaction in the field at 3 MAP a total of 220 survived. During the time of evaluation a

total of 86 genotypes (39.09%) had mean CBB scores of d” 2, and 116 genotypes (52.73 %)had mean scores of 2.1-3.0 and18 genotypes (8.18 %) had mean CBB scores of 3.1-4

and none of the genotypes had CBB score of 4.1-5.0. Analysis of metabolites potentially involved in conferring resistance to varieties indicated the role of phenolic and flavonoid

compounds in the response of plants to the disease. The prospect of utilizing these gene pools

for variety development was discussed.

Keyword: Bacterial blight, Cassava, Gene, Metabolites, Resistant



(ISTRC-AB)

Distribution of Sweetpotato planting materials in Northern Uganda

P, Rachkara1, S. W. Kalule 1, and R.W. Gibson2

1Faculty of Agriculture and Rural Development, Gulu University,

[email protected]

2Agriculture, Health & Environment Dept., Natural Resources Institute, University of Greenwich

Medway Campus, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK

Abstract

Sweetpotato is a crop that is grown and utilized by several households in Northern Uganda because it is considered a food security crop. The growing season stretches for several months. However the harsh dry season that follows the main Sweetpotato growing season

creates scarcity of planting materials (Sweetpotato vines) at the start of each main season.

This gap of scarcity of planting materials is bridged by an informal seed system engineered by a few farmers and traders. They have seized the business opportunity created by the dry

season. We mapped out and assessed the major actors who have ensured that Sweetpotato seed is always available during the main planting season. Farmers involved in Sweetpotato

vine production during the dry season utilize the lowlands for purposes of producing both vines and roots. At the onset of rain and stretching through the planting period, they sell the

vines to traders who resell these vines in the major markets. Surprisingly, farmers as far as

150km away access Sweetpotato vines from these markets. This informal system has been sustained by the major actors for more than six years and it has proven to be the major

source of Sweetpotato vines. We believe this system could support the dissemination of clean improved planting materials.

235



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236

Response of selected cassava (Manihot esculenta Crantz) genotypes to root

inducing hormone, IBA (Indole-3-butyric acid) under 3 growth conditions

Shirley Otukpa1, Ismail Rabbi, Gueye Badara, Michael Abberton, Peter Kulakow

International Institute of Tropical Agriculture, headquarters & West Africa Hub

PMB 5320, Oyo Road, Ibadan 200001, Oyo State, Nigeria

Abstract

Number of roots per plant is a major yield component of Cassava; a starchy root crop that is grown in the tropical regions of the world. Hence, breeding efforts to increase the number of

commercial roots could potentially translate to more productivity per unit of land. Commercially

available rooting hormone are well known to increase rooting potential crops and widely used in horticultural agriculture. In this research, we sought to investigate the effect of Indole

Butyric Acid (IBA), on the root production of cassava under 3 growth conditions; tissue culture, pot and field experiment. In the tissue culture experiment, nodal cuttings of selected

Cassava plantlets were sub cultured in two sets: without IBA and with 0.1 mg/l IBA; For pot and field experiments, stem cuttings were treated in two sets: without IBA and with 0.1 %

IBA. Data on root (root number, root length, root weight) were obtained. Analysis of variance

to determine the effect of hormone treatment and its interaction with genotypes were implemented using PROCGLM of SAS-V9.3. Results obtained from tissue culture experiment

showed highly significant genotypic effect for root length, hormone treatment and treatment by genotype interaction for both root number and root length of cassava. Generally, it was

observed that treated plantlets produced shorter but more root numbers relative to the untreated plantlets in vitro. Pot experiment showed similar response; highly significant effect for

genotypic response, hormone treatment and treatment by genotype interaction for root number

and root weight. Though there was a clear dramatic effect of IBA response in the tissue culture and pot experiment, such effect did not transcend to the field experiment. Field

experiment showed no significant effect on hormone treatment, though highly significant genotypic and interaction effect for root number and root weight, were detected. A further

field experiment using different levels of IBA treatments on a larger number of genotypes is recommended.

Keywords: Cassava; Indole-3-butyric acid; growth conditions


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237

1

1

1

1

1

Analysis of Inbreeding Depression in Five S

of African varieties

Cassava Families

Lydia Ezenwaka, Emmanuel Okogbenin, Olalekan Akinbo, Chiedozie Egesi,

Favour Ewa and Alex Ogbonna National Roots Crops Research Institute (NRCRI), Umudike, Nigeria; corresponding author

[email protected]

Abstract

Cassava is an out-crossing, highly heterozygous plant and is reported to suffer from inbreeding depression. The effects of inbreeding in cassava are still under-quantified. The need to unravel

recessive traits and explore additive genes in cassava would in the minimum require some

limited level of inbreeding in genetic improvement of cassava. A study to assess the performance of S progenies of five African cassava varieties (TMS 30572, TME 419, TMS

98/0505, TMS 01/1371 and TMS 98/0002) for six agronomic traits was conducted. The results of the average inbreeding depression (ID) levels for the traits are as follows: fresh

root yield (86.55%), fresh foliage yield (66.38%), harvest index (25.34%), root dry matter content (14.32%), plant height (-25.49%) and vigour (20.83%). The average ID obtained

indicated that harvest index, dry matter content, and vigour were not severely affected in

performance. The average trait value for plant height in the S was not reduced implying no inbreeding depression for this trait. The effects of ID were highest in fresh root yield and

fresh foliage yield which are relatively much more complex traits than others. Reduced heterozygosity associated with selfing (S ) appeared to have strong effects on both traits

thus underscoring the relative importance of non-additive genetic effects in their inheritance. For each trait, results identified individual S genotypes that substantially outperformed the

non-inbred parents likely representing transgressive segregants for favorable allele

combinations. This was observed mainly for plant height, DMC and vigour where ID values were lower. These results demonstrate that inbreeding may be strategically explored in

breeding to increase genetic gain and identify recessive traits. Advanced selfed generations are currently in development to screen for inbreeding tolerance in cassava to enhance genetic

improvement of the crop.



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238

Biofortification of cassava for pro-vitamin A in Nigeria: a model for collaborative

scaling out for reduction of vitamin A deficiency in Africa

Egesi C.N., Olasanmi B., Onyeka T. J, Njoku D., Ogbuekiri H. Okogbenin E.,

Ilona P., Parkes E.,and P. Kulakow National Root Crops Research Institute (NRCRI) Umudike, Nigeria.

International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. *E-mail: [email protected]

Abstract

Cassava presents a veritable vehicle for food and nutrition security in Africa when the agronomic performance and nutritional values are enhanced to compete with other common food staples. Breeding for enhanced pro-vitamin A cassava in Nigeria resulted an earlier

development of varieties that contained between 6-8 ug/g fresh weight basis of beta carotene.

These are being distributed by multiple partners in Nigeria to Nigerian farmers through an innovative pilot phase farming clusters approach to reach more than 2 million farmers within

2 years. Further efforts in breeding have resulted in the second generation varieties which are due for official release in Nigeria. These varieties show an average of 10 ug/g FW of

beta carotene and would be the benchmark for pro-vitamin A cassava varieties in the near future. In addition to the elevated carotenoid contents, these varieties are high yielding and

higher dry matter contents than the first generation pro-vitamin A cassava varieties. The

status, progress and achievements are discussed in the paper.



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239

SOCIO ECONOMICS

Farmers’ Valuations of Cassava Variety Traits in Southern Ghana: The Mixed

Logit Approach

Patricia Pinamang Acheampong*1, Victor Owusu2 and Gyiele Nurah2

1. Crops Research Institute, Kumasi, Ghana

2. Kwame Nkrumah University of Science and Technology

Abstract

The commitment of farmers to growing improved cassava varieties was analyzed using choice experiment and applying mixed logit model to estimating farmers’ willingness to pay

(WTP) amounts for various cassava variety traits. The study was based on primary data

collected from 450 cassava growing farmers in three cassava growing districts in southern Ghana. The results revealed that farm households value in-soil storage, disease resistance

and multiple usesmore than increased productivity. Farm households in Atwima district, Techiman Municipal area and Fanteakwa district were ready to give up ¢320, ¢208 and ¢97

in sales for increases in in-soil storage. The results also revealed that the trait productivity was not valued in as much as farmers value in-soil storage (longevity in the soil), disease

resistance and multiple uses. Farm households only would want to give up ¢1.40p, 88p and

72p in sales for productivity trait in Atwima District, Techiman municipal area and Fanteakwa District respectively. The limited storage facilities and underdeveloped market and value

chains for cassava rather discourage farmers for considering high output when making production decisions. The results have important implication for breeding of cassava varieties

and for subsequent adoption. The fact that farmers attach substantial weights to both in-soil storage and disease and pest resistance traits allude to the need for breeding varieties that

have the ability to stay longer in the soil and are highly resistant to pest and diseases.

Key words: Choice Experiment, Mixed logit, Willingness to pay, cassava, farmers


(ISTRC-AB)

240

Targeting agricultural research for development investments in cassava and yam

production systems in Africa: Evidence from Nigeria

Paul M. Dontsop Nguezet13, Victor Mayong2, Joseph Rusike 3

1 IITA – Bukavu, DR Congo,

[email protected]

2 IITA – Dar Es Salam, Tanzania,

[email protected]

3 IITA – Dar Es Salam, Tanzania

[email protected]

Abstract

There is increasing consensus that roots and tuber production systems have the greatest potential in tropical areas in Africa for increasing staple food production, farm incomes and

nutrition in order to reverse the current downward trends in per capita food production and

availability and food security. Because technological change is the major driver of productivity increases in agriculture and the source of new income streams, it is especially important to

examine how agricultural research for development are affecting food production, incomes and nutrition outcomes. We use national household survey data and apply the treatment

effects methods developed in the literature on econometric and statistical evaluation of social programs to analyze the current and potential impact of agricultural research investments on

adoption, production, income and nutrition outcomes in the context of heterogeneous responses to interventions and diversity in impacts. We find that there are large gaps between current

and potential impacts. These mostly result from inefficiencies in markets for agricultural

input and output, land, labor, credit, risk, information and externalities in the adoption process. We recommend that to tap the unexploited potential agricultural research for development

investments be targeted to favorable regions and complementary investments be targeted to improving supply of clean disease-free planting materials and fertilizers; mechanization of

production and cassava processing; capacity building of farmers; farmers’ organizations; marketing arrangements; and agricultural innovation systems.





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241

Socio-economic analysis of Yam bean (Pachyrhizuserosus)

processing to Gari in Benin

Patrice. Y. Adegbola1 , Prosper Houessionon1, Paul. Houssou2, Soniade

Ahouignan1, Denis Olou1, Jean Louis Ahounou2, Kerstin Hell3, Graham Thiele 4,

Pascal Fandohan2, Guy. Apollinaire. Mensah5. 1Programme Analyse de la Politique Agricole, Centre de Recherches Agricoles d’Agonkanmey,

Institut National des Recherches Agricoles du Bénin, 01 BP 128 Porto-Novo, Bénin 2Programme Technologie Agricole et Alimentaire, Centre de Recherches Agricoles


Porto-Novo, Bénin 3 International Institute of Tropical Agriculture 4 CGIAR Program on Roots Tubers and Bananas

5Centre de Recherche Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin. [email protected]

Abstract

P. erosus is a vegetable for which tubers can be processed to Gari. It is rich in nutrients (proteins, iron, etc.) and good to control malnutrition. The study aimed to analyze producers

and transformers’ perception of P. erosus processing to gari and assess its financial profitability. Kendall conformity test was used to rank the perceptions and the costs analysis was done to

compute the product profitability. Gari from P. erosusis had some features very similar to gari from Cassava: same color and texture but more firmness. Further; the gari of P. erosus

was easy to grate. Results showed differences between production steps for Cassava’s gari and gari from P. erosus. Gari from P. erosus had total processing time of 14.22 Man-hours

which was higher than that of Cassava gari (10.90 Man-hours). From 100Kg of a mixture of 50% P.erosus+50% Cassava, the quantity of gari obtained was 18kg. Processing of main

product (Tapioca): represents 77% of income gained from derived products. With this output,

transformers ‘equilibrium price (no gain and no loss) was 340F CFA. Labor productivity analysis revealed that, family labor was well paid by gari from P. erosus (2430.24 F CFA/

Man-day). Cash productivity was 1.18 (118%); which was superior to the credit interest rate of 20%. Sensibility analysis revealed that, when gari from P. erosus output increased by

30%, transformers’ gain was 25% of the investment cost.

Key words: P. erosus, Perception, Gari, technique performance, Profitability.



(ISTRC-AB)

242

Socio-economic analysis of Pachyrhizus erosus

in South and Central Benin

Patrice. Y. Adegbola1 , Prosper Houessionon1, Lys-Annie Loboté 2, Imayath Badarou1, Nestor Alokpaï2, Pascal Fandohan3, Guy. Apollinaire. Mensah4.

1Programme Analyse de la Politique Agricole, Centre de Recherches Agricoles d’Agonkanmey,

Institut National des Recherches Agricoles du Bénin, 01 BP 128 Porto-Novo, Bénin

2 International Institute of Tropical Agriculture

3Technologie Agricole et Alimentaire, Centre de Recherches Agricoles d’Agonkanmey, Institut

National des Recherches Agricoles du Bénin, 01 BP 128 Porto-Novo, Bénin

4Centre de Recherche Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du

Bénin, 01 BP 884 Recette principale, Cotonou, Bénin. [email protected]

Abstract

The introduction of new crops such as Pachyrhizus erosus face three (3) main constraints which are: the removal of flowers, the staking and pods’ harvesting. To overcome these

constraints, two technologies: “removal of flowers without staking” and “ablation staking”

were introduced. The objective of the study was to analyze producers’ perception and economic performance of P. erosus introduced in southern Benin. Data were collected from fifty-eight

(58) farmers producing Pachyrhizus erosus and margin and productivity calculation method. W and T tests were used for analysis. The results showed that out of the technologies used,

the technology “ablation staking” generated significantly higher net margin than “removal of flowers without staking” which are respectively 722,889.22 CFA and 392,453.85 CFA. Labor

productivity is 2230.64 CFA and the one for the cash is 90.12%. In addition, the cost of

tubers P. erosus is estimated at 71.8 CFA. The results of economic performance compared to respondents’ major crops (corn, peanut and cassava) indicated that the culture P. erosus

may generate income for producers. Research must therefore work for the popularization of P. erosus culture.

Keywords: P. erosus, Economic Performance, Perception, Benin



(ISTRC-AB)

243

Analysis of the factors that Influence Root and Tuber Crops Production in Benue

State Nigeria: Implication for improved Agricultural productivity.

Tokula, M.H. Wende, F. Ekwe, K.C. and Asumugha, G.N

[email protected]


Abstract

The study investigated the factors that influence root and tuber crops production in Benue State. 90 extension contact farmers were randomly sampled from Otukpo, Ado, Ogbadibo

Okpoku and Ohimini Local Government areas for study. Data were collected with the aid

structured questionnaire and analyzed using descriptive statistics (frequency and percentage scores) and multiple regression analysis. Results showed that the major constraints to root

and tuber crops production were high cost of labour, drudgery in peeling of cassava and the processing of gari and high transport cost of fresh roots to markets. It further revealed that

storage losses, scarcity of fertilizer and high cost of seed yams also constituted the major constraints to yam production. The regression results showed that education and access to

extension services were positive and significantly related to root and tuber crops production

at 1% level, age and household size were also positive and significantly related to improved root and tuber crops production at 5% level. Marital status was however negative but

significantly related to production at 5% level. It was concluded that education level of farmers and access to extension services had a major influence on the production of root and tuber

crops, and therefore recommended that extension services be strengthened to facilitate higher productivities among farmers.



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244

Gender Enterprises in Cassava Production and Processing among Farmers in

Abia State: The Case of Adopted Village Project

Ekedo, T.O, Nwakor F.N, Okoye B.C, Ekwe K.C. Asumugha G.N

National Root Crop Research Institute Umudike, Umuahia.

[email protected]

Abstract

The study investigated the role of gender in cassava production and processing among farmers in Abia State, Nigeria. The population sample was drawn from two Local Government Areas

in Abia State who were adopted by National Root Crop Research Institute, Umudike for

agricultural demonstration (adopted village project).About 50 respondents made up of 25 male and 25 female farmers were purposively selected for the study. Well structure

questionnaire were used to elicit information from the respondents. Data collected were analyzed by means of descriptive statistics such as frequency tables, percentages, means,

and likert designs. The result of the study revealed a higher level of participation among men as against women in such activities like bush clearing and burning (mean score 1.92), mounding

(1.84), gathering of input (1.96), planting of crops (1.92), fertilizer application (1.56), weeding

(1.84), record keeping of labour use (1.72), record keeping of revenue realized (2.52), garri processing (1.72) and processing of high quality cassava floor (2.32). this is a surprise especially

when compared to lower participation of women in similar activities such as bush clearing and burning (means score1.08), mounding (1.0), gathering of inputs (1.28), planting of crops

(1.52), fertilizer application (1.32), weeding (1.48), garri processing (1.48), record keeping of revenue realized (2.28), record keeping of labour use (2.24) and processing of high cassava

floor (2.28). However, the result also showed that the respondents had a favorable perception

of adopted village project. The evidence is from the positive responses of those statements which highlight the positive effects of adopted village project.

Key words: Gender, cassava, production, processing, adopted village



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245

Constraint Analysis of Farmers Adoption of Sweetpotato Utilization Technologies

in Southeast Agro-Ecological Zone of Nigeria.

Nwaekpe J.O., H.N. Anyaegbunam, G.N. Asumugha, K.C. Ekwe and B.C. Okoye

National Root Crops Research Institute, Umudike. [email protected]

Abstract

This study was undertaken to determine the constraints militating the adoption of sweet potato utilization technology in Abia and Ebonyi States of Nigeria. A multi-stage randomized sampling technique was used to select 120 farmers from both states. Data collected were

analyzed with descriptive statistics like mean, frequency distribution, percentages and Likert

scale rating. The results show that 70% of the farmers were aware of sweet potato processing technology but only 26.67% of them adopted the technology. Constraints that scored 3.0 and

above hindered the adoption of sweet potato utilization technology but those below did not. Constraints such as ‘inadequate extension officers (3.23)’, ‘lack of fund (3.76)’, ‘untimely

interventions from the institute (3.37)’, ‘lack of two-way communication (3.01)’, ‘lack of regular training programs (3.05)’, and ‘lack of support services in terms of credit and subsidy

(3.74)’ were the major constraints militating against the adoption of sweet potato processing/

utilization technology by farmers in the study area. The study thus, recommends the provision of support services like credit facility to farmers to enable them diversify their means of

livelihood and that NRCRI, Umudike should ensure adequate follow-up after trainings.



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246

Refocusing Cassava Enterprises Towards Rapid

Agricultural Transformation in Nigeria

Ekwe 1 K . C. Ironkwe 1 A. G and Okoro2 Basil

1National Root Crops Research Institute, Umudike, Abia State, Nigeria

2National Agric. Extension and Research Liaison Services, Zaria (SE, Zone)

[email protected] (+2348063599791)

Abstract

The current Agricultural transformation agenda in Nigeria was envisioned to revamp the

sector, ensure food security, diversify the economy and enhance foreign exchange earning through a rapid development of value chains of selected crops of strategic importance. The

transformation action plan targets provision of improved inputs (planting materials and fertilizer), increased productivity as well as the establishment of staple crop processing zones. In

consideration of its tremendous potentials for development of Nigeria’s economy, Cassava

was selected as one of the nine commodities in the transformation programme. This paper x-rays the goals of the transformation agenda for the cassava crop which includes among

others (a) linking demand for cassava products in the industrial, export and food sectors to reliable supply by introduction of innovative packages for improved production and supply

chain management (b) raising productivity through the demonstration and adoption of improved production technologies by clusters of farmers (c) building around farm clusters, market

institutions for the long term sustainable development of the Cassava sector. The paper

therefore recommends that strategic research efforts directed towards development and multiplication of planting of high yielding cassava varieties, development of standard and best

suited agronomic practices for the various cassava growing agro-ecologies in the country. The development of improved recipe for cassava based confectionaries with enhanced shelf-

life, crumb quality, mouth feel, colour and taste should be promoted as a way to ensuring that the goals of the transformation agenda are achieved.

Keywords: Cassava research, value chain, improved technologies, Agricultural Transformation




(ISTRC-AB)

247

Responsiveness of farmers’ to root crops technologies disseminated through

mass contact channels in abia state

Ekwe K.C., Tokula M.H. Ekwe Chioma and Ironkwe, A G

National Root Crops Research Institute, Umudike Abia State, Nigeria.

Abstract

Seven root crops technologies developed by National Root Crops Research Institute, Umudike, Nigeria were intensively promoted, popularized and rapidly disseminated to farmers in Abia State and beyond through selected mass contact channels. The various mass contact channels

employed in the campaign included radio, television, newsletter, magazines/newspaper,

exhibition and extension guides. This study investigated the responses of farmers to the technologies disseminated through the listed mass contact channels in Abia State. A total of

150 farmers randomly selected across the three agricultural zones of the state were involved in the study. Data for the study were collected with use of structured interview schedules

and analyzed with descriptive statistics such as frequencies, percentages and mean as well as Probit model statistics. Results indicated that among the farmers, there were relatively

high levels (65%-85%) of awareness of the technologies. Also majority (47%) of respondents

obtained most information on the technologies through the radio. Regarding their responses towards the technologies, majority (40%) of respondents was still making further enquires;

26% had adopted the technologies while 12% had not made any positive responses towards the technologies. Results of this study have some policy implications. First, high level of

awareness of agricultural technologies should be sustained among farmers by creating such enabling environment through policy that will persuade government owned media houses to

promote agricultural programme at no charge. Secondly, policy guidelines that will facilitate

regular, effective and participatory interaction between extension personal and farmers through the mass media and other information and communication technologies (ICT) should be put

in place in Abia State and Nigeria in general.


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248

Increasing Africa’s competitiveness in the Global Cassava Market through

mechanized production and processing

Kolawole, O. Peter1 and Abass, Adebayo2

1International Institute of Tropical Agriculture, Ibadan, Nigeria. 2International Institute of Tropical Agriculture, Regional Hub for East Africa,

Dares Salaam, Tanzania.

[email protected]

Abstract

Cassava can easily substitute African grain requirements, but post-harvest processing of cassava is laborious and a source of drudgery for women and children, and only little can be processed at a time. Cassava processing requires good machines. Most available machines

support only intermittent methods, which are becoming inadequate. For most smallholders,

the cost of labour is becoming unaffordable and production costs are increasing beyond their financial means. These limitations and challenges pose significant barriers to cassava

commercialization. Cassava products in Africa are not competitive in the global market partly because of little mechanization. Problems affecting full commercialization of the cassava

sector were explained in the paper to support the need for process orientation towards mechanization to replace subsistence cropping systems. A shift from the traditional rudimentary

methods to improved medium- to large-scale postharvest technologies is necessary. Affordable

labour saving devices will improve and add value to cassava products. Technology transfer is required to make these devices locally and reduce the huge import bills for importing machinery,

which further increases production costs and reduces the opportunity for competitive production of cassava. In this respect, the advances made in the last decade on local production of

machinery for cassava processing make such sentiments evidently compelling. Future advances in cassava mechanization would require collaborative research between cassava

breeders and postharvest engineers to increase Africa’s competitiveness.



(ISTRC-AB)

249

Analysis of transaction costs in cocoyam marketing in Abia State, Nigeria

Kadurumba Chinyere

National Root Crops Research Institute Umudike, Abia State Nigeria

Abstract

The study identified factors which influenced transaction costs of cocoyam marketing household in Abia state, Nigeria. Multistage random sample technique was used in selecting two hundred (200) respondents for the study. A well-structured questionnaire was used in collecting data

from the respondents and the data collected were analyzed using simple statistical tools like

frequency tables, percentages and multiple regressions model. The result revealed that majorities (51.0%) of cocoyam marketers were females and cocoyam could be regarded as

female crop. Also the result of the multiple regression analysis, double log function were selected as the lead equation and nine variables were significant at various alpha level of

probability, with respect to the diagnostic statistics, R2 of 0.786. The significance F-ratio values of the independent variables indicated that the overall test is significance.


(ISTRC-AB)

250

Global, regional and local drivers of change in cassava value chains in selected

countries in Africa: Implications for upgrading smallholder systems

J. Rusike 1*, A. Adebayo1, T.Abdoulaye 2, A. Alene 3, W. Bowser2, V. Manyong1

International Institute of Tropical Agriculture-Tanzania, PO Box 34441, Dar es Salaam,

Tanzania. Telephone (255) 22 2700092* E-mail [email protected]. 2. IITA-Ibadan 3. IITA-

Malawi

Abstract

Cassava-growing smallholders in sub-Saharan Africa are operating in political, economic,

social and technological environments that are currently undergoing profoundchange and development.The paper uses the value chain framework and applies cointegration and error-

correction modeling and interrupted time-series analysis to primary and secondary data collected in the major cassava growing and consuming countries. The paper analyzes changes

in structure and dynamics underway in the value chains; drivers of change; end-market opportunities; and constraints on upgrading smallholder systems and technological, institutional,

organizational and policy innovations with significant potential to resolve constraints, permit

smallholders to exploit opportunities and improve the performance. Results show that that production and consumption are geographically concentrated and that local and domestic

markets are developing into regional and international markets. Market liberalization, urbanization and globalization are driving changes in end markets through integration of local,

national, regional and international markets and transmission of international and urban market prices to farm gate prices through arbitrage.Supply response of smallholders is being driven

by point interventions to resolve specific bottlenecks along the value chain. In order to

overcome constraints throughout the chain requires holistic value-chain interventions including tools, market structure, policies and infrastructure that shift the system.

Keywords: Cassava; value chain, Africa, cointegration, error-correction modeling, interrupted

time-series analysis



(ISTRC-AB)

251

Priorities for research of a global cassava program in sub-Saharan Africa:

Perspectives of scientists and farmers

J. Rusike 1, T. Abdoulaye 2, G. Hareau3, U. Kleinwechter3, B. Creamer4, D. Pemsl5,

H. Kirscht6, A. Alene 7

1International Institute of Tropical Agriculture, Dar es Salaam, Tanzania; 2International Institute

of Tropical Agriculture, Ibadan, Nigeria; 3 International Potato Center (CIP), Lima, Peru; 4

Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia; 5Bioversity International,

Montpellier; 6International Institute of Tropical Agriculture, Yaoundé, Cameroon;7International

Institute of Tropical Agriculture, Lilongwe, Malawi

Abstract

In sub-Saharan Africaagriculture is characterized by widevariation inagro-ecological, technological, social, economic, policy, infrastructural and political conditions. This makesit

difficult toset priorities foragricultural research programs to provide global public goodsandhave impact ondesired outcomes ofinterest.There is much debate about the relative efficiency and

effectiveness of setting priorities using global versus national approaches and whether or not

National Agricultural Research Systems should depend on centralized priority setting of CGIAR global programs or they should use their own decentralized approaches to deal with local

diversity.We use data on rankings ofconstraints on cassava production and supply and research options to resolve the constraints collected through surveys of farm households and experts.

We apply the scoring method using latent variable modeling for multivariate responses to analyze the rankingsaccounting for dependency among them and interactions with background

characteristics of respondents. The estimatesindicate that the major constraints and research

options are global rather than local. Much overlapexists in top-ranked constraints and optionsperceived by farmers and experts in different countries and agro-ecological zones.

We conclude that there is a convergence of perspectives ofresearch priorities and that a global approach can be used to set an agenda for long-term research on cassava to solve

constraints and have impact over a broad geographical range.


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252

Effects of variety and fermentation periods on the yields of ethanol produced

from sweetpotato flour and starch

1Etudaiye, H. A., 2Oti, E and 3Sanchez, T

1, 2 National Root Crops Research Institute, Umudike, PMB 7006, Umuahia, Abia State, Nigeria 3International Center for Tropical Agriculture, Palmira, Colombia

[email protected]

Abstract The effects of variety and fermentation periods on the quality of ethanol produced from sweetpotato flours and starches were studied. Fresh roots of three (3) sweetpotato varieties

(TIS 2353.OP.113, TIS 87/0087 and TIS 8164) were processed into flours and starches using standard procedures. Fermentation periods were varied for 0hr, 12hr, 24hr, 48hr and

72hr. Decrease in glucose and pH were observed as days of fermentation increased while total acidities, ethanol concentrations and ethanol yields increased. Ethanol yields from

fermented starch slurries of each sweetpotato variety were higher than that of the flour slurries. Ethanol yields at 72 hours of fermentation from flours and starches of sweetpotato

varieties were IS2532.OP.113 (15.48% and 21.00%), TIS 87/0087 (15.27 and 18.14%)

and TIS 8164(14.82 and 20.68%), respectively. There were significant differences (P<0.05) in the ethanol produced from flour and starch slurries at different fermentation periods of

0hr,24hr,48hr and 72hr. Flour and starch slurries of sweetpotato variety IS2532.OP.113 fermented for 72hr gave highest yields of ethanol. However, ethanol yields from flours and

starch of the sweetpotato varieties were higher than the values previously reported by some authors. This could be an indication of high dry matter and amylose of the flours and starches,

activities of the granular starch hydrolyzing enzyme and the yeast strain Saccharomyces

cerevisiae used. Production of ethanol from sweetpotato starch and flour should be promoted as this can be one important way to develop biofuel substitutes in Nigeria.



(ISTRC-AB)

253

First Step toward the orange-fleshed sweetpotato value chain in Ghana: Linking

extension to private seed producers.

Kwabena Assure, Kwadwo Adofo, Kwabena Acheremu, Iddrisu Abdul-Rahaman,

Sampson Ndego, Sabastian C. Waltia, Abu Baayirinaa, Constantine Faar, Dadoza

Mac, George Apetorgbor, Victoria D. Abankwa, Vincent Subbey, Appiah K.

Boateng, Esi Amoaful, Eric Dery, E. Carey

Abstract

The potential of orange-fleshed sweetpotato (OFSP) to sustainably contribute to combating

vitamin A deficiency in Ghana is increasingly recognized, but has not yet been realized. In 2008, the OFSP cultivar Apomuden was released, but has not been widely adopted either for

home gardens or markets. Recently, however, efforts by Farm Radio International’s OFSP project and the Reaching Agents of Change project, as well as mention of OFSP in Ghana’s

agricultural policy documents, are leading to increasing awareness and demand for OFSP. In order to prepare for and respond to increasing demand for OFSP, we undertook to a small

but concerted effort to multiply planting material of Apomuden, in five regions of Ghana

where sweetpotato is important during the 2012/2013 dry season. Vine multipliers (38) were identified in five target production zones and supplied with (25,000) planting material of

Apomuden. A planting distance of 40 cm x 30 cm on beds was recommended for multipliers in order to allow for production of both vines and roots. Multiplication sites were visited and

monitored regularly until vines were ready for distribution. Success of the multiplication effort varied considerably among multipliers. Destruction of planting material by animals, floods

and drought was encountered in some locations while reduction in quality due to senescence

was observed in other locations. However, clean planting material was obtained from a good number of locations. Planting material was purchased (300 cuttings for GHS 4) from multipliers

during the early part of the 2013 rainy season and distributed to 609 households. Multipliers sold and/or consumed roots as well. Farmers who successfully grew and sold planting

material are interested in continuing this enterprise in the coming seasons. Concerted efforts to create market demand for OFSP are underway, including the ongoing Farm Radio

international Programming, and will be complemented by additional efforts to disseminate

nutritional and utilization messages. Contracts may be used to encourage seed multipliers to follow through on commitments and reduce cases of loss or abandonment.


(ISTRC-AB)

254

Transformation through Integrated Agricultural Research for Development

(IAR4D): Experiences from Cassava Value Chain Innovation Platform –

DONATA Project, Ghana.

Grace Bolfrey-Arku1,2, Emmanuel Osei-Adade 3, I. O. O. Ansah2, Joseph Manu-

Aduening2, Alfred Anaman3, Jonas Adu2,Thomas Asare Baffour4, Ebenezer

Aboagye 3, Patterson Osei Bonsu2

[email protected] 2CSIR-Crops Research Institute, Box 3785, Kumasi, Ghana

3Ministry of Food and Agriculture (MoFA), Box 100, Wenchi, Ghana 4 Ministry of Food and Agriculture (MoFA), Box 86, Sunyani, Ghana

Abstract

Attaining sustainable agricultural development is a concern and cassava, (Manihot esculenta Crantz), with an AGDP of 22% (MOFA/SRID, 2012), offers opportunity for enhanced growth

in income as well as reduction of income variability in Ghana. Adoption of improved cassava varieties is low due to several factors. Few of them are limited knowledge on the attribute of

the varieties, minimal access to market information, inefficient production practices and value

addition for higher premium. In 2011 an innovation platform on cassava value chain – Dissemination of New Agricultural Technology for Adoption in Africa (DONATA) was initiated

in the Wenchi Municipal to transfer, share and disseminate improved technologies and indigenous knowledge to actors along the cassava chain. Participatory approach were used

to integrate varying challenges of different stakeholders around three priority entry points: (1) Access to improved cassava varieties and enhanced soil fertility management; (2) Use of

herbicides to control perennial weeds in cassava; (3) Cassava product development and

market access. Varied dissemination and knowledge sharing strategies employed coupled with transparency of the facilitators enhanced interactions, participation and trust. External

factors as market opportunities, Research Extension Farmer Linkage Committee (RELC); collaboration with RAILS and other stakeholders influenced the success of the IP. Direct

beneficiaries has within 2 years grown from 34 in 4 platforms to 190 (75 M, 115 F) in 5 platforms with 111 indirect beneficiaries. Achievements include access to 5other improved

varieties (Nkabom, Ampong, Bronibankye, Esambankye and Otuhia), besides the 2

(Bankyehemaa and IFAD) that existed prior. Seventy percent (70%) increase in use of herbicide nozzle has reduced glyphosate application rate by 60% (10 L/ha to 4 L/ha); row

planting increased population by 47%, while yield was raised from 12 -16 t/ha to 42 t/ha. An outcome is purchase of used motorbike by a platform member from Nkonsia even as

sensitization on sustainability encouraged Ayigbe Platform to contribute $1250.00 towards the construction of Good Processing Centre (GPC). Marketing challenges of Nkonsia IP

resolved through a transporter who realized a market opportunity as well. The platform

offers opportunities for an emerging enterprise and leverage for integration of IAR4D systems into WAAPP Phase II.

Key Words: DONATA, Innovation Platform, Cassava value chain, Sustainability, IAR4D



(ISTRC-AB)

255

Community Analysis of Root & Tuber Crops Farming System in Southeastern

Nigeria

Asumugha, G. N., H. N. Anyaegbunam, B. C. Okoye and J. C. Okonkwo National Root Crops Research Institute, Umudike, Nigeria. [email protected],

[email protected]

Abstract

Major root and tuber crops in south-eastern Nigeria include Cassava, Yam, Sweetpotato and Cocoyam. Many of the poorest farmers and food insecure people are highly dependent on

these crops as principal sources of food, nutrition, and cash income. The cropping pattern

has been mixed cropping. Major problems include land tenure system (fragmentation of holdings) lack of inputs and pests and diseases. There is also high cost of seed and of labour.

Fewer households are headed by women. Members of the family constitute the internal labour force.

Hired labour is sometimes employed. Female farmers continue to form an active part of the agricultural population. These rural women mostly do not have access to credit. Farm

household sizes are in the range of 6-8. Farm sizes are generally small usually less than 2 ha.

Most farmers use low yielding varieties of root and tuber crops obtaining yields which are far lower than the potential yields of these crops. The farmers use minimal external inputs

particularly mineral fertilizers and soil amendments. Due to availability of forage and grasses in this zone, farmers also keep livestock particularly small ruminants such as sheep, goat and

chicken. Livestock is, however, not well integrated in the farming system. There is therefore, the need to increase productivity through the use of high yielding varieties, integrated livestock

and soil fertility management. There is the need also to regularly develop new food and non-

food products from root and tuber crops to expand the market and generate income.





(ISTRC-AB)

256

Cassava Products Development in Nigeria; Policy Imperatives.

*Okafor, Obiageli Evelyn; Ogunwusi, A.A. and Jolaoso, M.A.

Raw Materials Research and Development Council (RMRDC), Abuja

*[email protected]; Mobile: +234-8067771070.

Abstract

Cassava, (Manihot esculenta) is one of the pivots of economic revolution in Sub-Saharan Africa. From its poor man’s food status, cassava has assumed a major role as food crop of high value added potentials. It has transformed to a cash crop of wide industrial applications

in sectors such as brewery, pharmaceutical and confectionery industries. Cassava is well

known and cultivated in every state in Nigeria by over 70% of the rural population. In the quest to exploit the emerging potentials of cassava to boost the national economies, many

African countries are forming development initiatives on cassava. Nigeria inaugurated a cassava presidentia l initiative in July 2002 with the objectives of creating awareness among

farmers on the opportunities in the cassava markets worldwide; increase the crop’s area of cultivation to 5 million hectares with a harvest target of 150 million tons annually and to

generate up to US$5 billion export revenue annually. It also targets to produce 37.5 million

tons of cassava products such as industrial and pharmaceutical starch, etc. which are presently imported. Achieving this goal requires tweaking existing policies and initiation of market

friendly guidelines and initiatives. This paper discusses policy issues favorable tocassava products development in an increasingly competitive global environment.

Key words: Cassava, presidential initiative, policy, economy.




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257

Processing and marketing of Fried Cocoyam (Xanthosoma sagittifolium) Chips in

Ajilete, Ogun State Nigeria

*Idowu-Adebayo Folake1, Sanni, L.O2, Adebowale, A.A2, Adegunwa, M.O3

and Oni, O.K.1

1Department of Food Science and Technology, Federal University Oye-Ekiti, Nigeria 2Department of Food Science and Technology, Federal University of Agriculture,

Abeokuta, Nigeria 3 Department of Food Services and Tourism, Federal University of Agriculture, Abeokuta, Nigeria

* [email protected] +2348034467470

Abstract

The research was carried out to assess the traditional processing and marketing of fried cocoyam chips in Ajilete, Ogun State, Nigeria. Socio-economic characteristics, raw materials

source, production, distribution and storage method of fried cocoyam chips processors were

investigated. Validated questionnaires were administered to the processors of fried cocoyam chips which happened to be 100% female and where not engage in any other job. 60% of

their age ranged from 31-40years while 40% were above 41years. 60%, 20% and 20% of the processors had primary, secondary and tertiary education respectively. The results showed

that 100% of the processors sourced their raw materials from the market and stored them on the floor without pallet. 100% used firewood and palm kernel as their sources of energy.

20% produced fried cocoyam chips in less than three days per week while 80% produced

from five to six days. 40% of the processors estimated income per day ranged from ten thousand and one (N10, 001.00) naira to twenty thousand (N20,000.00) naira, 40% ranged

from twenty thousand and one (N20,001.00) naira to thirty thousand (N30,000.00) naira while 20% above thirty thousand and one (N30,001.00) naira. 100% wrapped their unpackaged

fried cocoyam chips in a black polythene bag and stored inside raffia basket. Fried cocoyam chips vended along Sango-Oshodi express way are produced in Ajilete to generate wealth

and ensure food security for the women and their households.

Keywords: Processing, marketing, vended fried cocoyam chips, questionnaires, food security.




(ISTRC-AB)

258

Farmer preferences for cassava attributes in Oyo State, Nigeria: A choice

experiment investigating potential adoption of vitamin A enriched yellow cassava

Dorene Asare-Marfo, Ekin Birol and Adewale Oparinde

[email protected]

HarvestPlus, c/o International Food Policy Research Institute, 2033 K St. NW, Washington DC,

20006, USA

Abstract

Vitamin A deficiency (VAD) is a major public health problem in Nigeria. One potential solution is biofortification of staple crops, such as cassava, with vitamin A. Conventionally bred Vitamin

A enriched cassava varieties have been released and their delivery will start soon. Owing to

their high beta carotene content these varieties are yellow in colour. In order to inform delivery and marketing of these new varieties, farmer preferences for several cassava

attributes, including colour, vitamin A content and breeding method, should be investigated, along with more conventional traits such as yield, maturity and price of planting material. In

this study we employ a choice experiment to investigate farmer preferences for these cassava varieties. Data were collected from546 rural cassava producing and consuming households

in Oyo state and analyzed using a conditional logit model (CLM) for all households, as well as

for the four distinct zones that comprise Oyo state. The results reveal that overall farmers prefer higher yielding, earlier maturing and cassava varieties with cheaper planting materials.

Even though farmers strongly prefer varieties with Vitamin A content, they prefer light colour gari to yellow or palm oil mixed gari. There is significant heterogeneity across the four zones

of Oyo state and future research will investigate this heterogeneity further by using random parameter logit model with interactions, as well as a latent class model.



(ISTRC-AB)

259

Gender operation and labour utilization in sweetpotato production in Ebonyi State

Southeastern Nigeria

G.O. Nwaigwe, M. Mazza, and E. C. Agoh

National Root Crops Research Institute, Umudike PMB 7006 Abia State Nigeria.

[email protected]

Abstract

This study was undertaken to determine the gender operation and labour utilization in sweetpotato production among farmers in Ebonyi state southeastern Nigeria. Purposive random sampling technique was used to select 120 sweetpotato farmers across the three

agro-ecological zones in Ebonyi State in 2011. Descriptive statistics tool was used in analyzing

labor gender, utilization, varieties planted and access to planting materials. The results show that family members were the main source for labor 75% while 25% of their labor was hired.

Also 7.9% activates were dominated by the female while 4.5% activities were dominated by male. Labor input (79 man-days) was utilized for planting, weeding, mounding and harvesting,

next largest labor 16.8% for land clearing and vine cutting. Improved varieties planted were 34.8% while majority 65.2% planted local varieties. Procured planting materials from pervious

harvested field were 66.7% while 33.3% procured through irrigation technology.

Commercialization of production by given giant to sweetpotato farmers would encourage men to play more roles in the production activities.

Keywords: Gender, Labor, Sweepotato Production and Ebonyi State



(ISTRC-AB)

260

Price integration analysis of some selected cassava root markets in south

Eastern Nigeria

**Anyaegbunam,H.N,*Nwaekpe J,*Asumugha G.N and* Okoye,B.C

*Extension Services Programme ,National Root Crops Research Institute

Umudike,PMB7006,Umuahia,Nigeria

** [email protected]

Abstract

The study was carried out in 2012 in south eastern Nigeria on analysis of price integration of some selected cassava root markets and problems associated with cassava marketing. It

was informed by the fact that in a food market economy like Nigeria, an efficient, integrated

and spatial pricing system usually leads to economic growth. This is true if it effectively minimizes the price differential in traded product due to costs of transportation, storage and

processing over time and space. A Multistage random sampling technique was used in selecting states, respondents and markets. A total of two states, 120 marketers/respondents and eight

markets were randomly chosen. The list of marketers who pay union dues formed the sampling frame. Primary data were collected using structured questionnaire and interview schedule.

Analyses of data were done with simple descriptive statistics and bivariate correlation

coefficient. The results of the finding revealed that the markets are spatially separated but prices are not integrated. The major problems of cassava marketing identified include

perishability of cassava roots, bulkiness, poor access road, lack of storage and credit facilities. Others are attitude of law enforcement agents, inadequate good processing technology, market

stalls and high transportation costs. It is therefore; recommended that policy geared towards provision of infrastructural facilities to enhance marketing activities and efficiency is advocated.

Marketers are also encouraged to form cooperatives for capital-build up, to establish a bulking

centre and to enjoy economy of large scale.

Keywords; Price, Integration, Cassava root, Correlation and Market



(ISTRC-AB)

261

Farmers’ perceived adoption risks associated with Nicola variety of potato in Jos

Plateau, Nigeria

Ekwe K.C, Anyaegbunam H.N, Amadi C.O, Dung E.A, Dalyop T Y, Lenka D

National Root Crops Research Institute, Umudike, Nigeria

Abstract

The Nicola variety of potato is very popular among potato farmers in jos plateau area of North Central Nigeria. However, its adoption rate still at 67% indicates that farmers are

wary about certain risks associated with use of the variety. a in view of the for going, a study was carried out in Jos Plateau, Nigeria To examine farmer perceptions of characteristics of

the Nicola improved potato variety as well as their perceived risks associated with adoption of the Variety. Seven communities notable for potato production on the Jos plateau were

visited for the study .50 potato farmers were sampled and interviewed using structured questionnaire. The data collected were analysed with descriptive statistics such as tables,

frequencies and percentages. Also, the probit ordinary least square analysis was conducted

to determine effects of the perceived risks on adoption of the variety in the study area. Result of the study showed that 52% of the respondents perceived that the Nicola variety

adapts and grows well in Jos Plateau while 28% indicated that the variety does not grow well in Jos Plateau. Also, most respondents perceived that high initial cost of adoption (90%) High

susceptibility to Diseases and potato Pests (73%) were risk factors associated with adoption of the Nicola. Moreover, the probit analysis further indicated that susceptibility of Nicola to

diseases, initial cost of adoption, incidence of wild fire and theft of the produce from farms had significant negative effects on adoption of the Nicola variety.

Key words: Perception, Adoption Risk, Nicola Variety, Potato


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262

The health benefit of the nutrient and phytochemical compositions of

sweetpotato: - A review

Alum, E. A., Amajor J.U. and Awah J. I.

Sweetpotato Research Programme, National Root Crops Research Institute, Umudike, P.M.B.

7006, Umuahia, Abia State, Nigeria

[email protected]

Abstract

Sweetpotato (Ipomoea batatas L.) is a highly valued crop with enormous nutrients and phytochemicals. This paper examines the health benefit of the nutrient and phytochemical

compositions of sweetpotato. The paper highlights research efforts being made to improve

the nutritional content of sweetpotato via bio fortification. Equally highlighted are procedures for cooking sweetpotato to ensure retention of its nutrient and phytochemical values. This

article emphasizes the great need to launch a campaign to popularize this crop as an integral part ofthe daily menu, in the forms of fresh cooked or processed products and to either help

immune-debilitated persons such as people living with HIV/AIDS (PLWHA) and those who take care of them set up their sweetpotato farms to improve their diets or provide them with

sweetpotato supplement on antiretrovira l treatment, considering that they are interested in

whatever might benefit their health.



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263

Level of awareness, factors and constraints to sustainable adoption of improved

root and tuber crops in Abia State, Nigeria

Edoh, N. L., Nwaogu, A.S. and Egesi, C.N.

Biotechnology Program National Root Crops Research Institute (NRCRI), Umudike, Nigeria.

Abstract

The study focused on sensitization and orientation of improved root and tuber crop production in 5 locations (Umuahia South, Ikwuano, Bende, Isi-alangwanorth, and Uzuakoli) in Abia State Nigeria. It examined socioeconomic characteristics of root and tuber crop farmers; the

level of awareness of improved root and tuber crops production, the acceptance of the newly

released root and tuber crop varieties from NRCRI by farmers, and the environmental factors affecting the marketing of root and tuber crops. A combination of random and purposive

sampling were adopted for the selection of respondents (improved root and tuber crop farmers) using questionnaire. Data were analysed statistically. About 64 % Farmers within age 47

were female, 60 % were married, experienced, and educated. The acceptance of UMUCASS 42 and UMUCASS 43 by farmers was 43 %, Ex-igbaram and Centennial was 14 %, TDr

89/02660 and TDr 89/02602 was 26 %, NXs004 and NCe009was 17%. Only 40 % of the

farmers specialized on cassava production. Important factors affecting the root and tuber crops farmers include gender, age, education, extension services, income and environment.

About 69 % of the farmers were constrained by low production capital. It is recommended that credit facilities should be extended to rural farmers. Furthermore, for optimal productivity

and sustainability, government should also provide the rural dwellers with access roads and other infrastructures.

Key words: Awareness of new varieties, adoption factors


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264

Potential for commercialization of cassava production in the Mpumalanga

province of South Africa

M.E. Rauwane 1, N.M Vilane 2 and T.G. Chabikwa1

1Agricultural Research Council – Biotechnology Platform, Private Bag X5,

Onderstepoort 0110, South Africa 2Department of Agriculture, Private Bag X11318, Nelspruit 1200, South Africa

[email protected]

Abstract

Cassava is a resilient crop that can grow and produce high yields in areas, which are not suitable for the cultivation of cereals crops. Cassava seldom requires supplementary fertilizers

or irrigation, this makes it an ideal crop for poor communal farmers. However, despite its

superior attributes, cassava has been neglected by the scientific, industrial and legislative sectors and is thus considered an ‘orphan crop’. In South Africa, cassava is largely cultivated

as a secondary crop by small-scale farmers on marginal lands. A was survey conducted on cassava cultivation in the Mpumalanga province of South Africa seeking to elucidate farming

systems as well as the nature and purpose of cultivating cassava. The survey confirmed that cassava was highly adaptable to extremely low rainfall (<200mm p.a.), high temperatures

and sandy-loam soils. Yields of approximately 2 kilograms per plant were reported without

fertilizers and less incidence of pests. The survey also highlighted the often-overlooked aspect of indigenous technical knowledge with regards to ‘on-field’ farmer ‘cultivar’ selection criteria,

which include early bulking and low cyanogenic potential. The farmers concurred that flowering and surface cracks are the primary indicators of physiological maturity, which occurs within

5-6 months after planting. The exchange of planting material amongst farmers ensures high level of homogeneity of the landraces planted and thus production practices. The communal

farmers, of which most are women (>70%), are supported by the Department of Agriculture,

which provides draught power and extension services. The target market for the tubers is largely within the community where it is consumed as a delicacy and annual festivals

particularly traditional initiation ceremonies.

Key words: cassava, neglected, potential, resilient, selection



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265

ANALYSIS OF THE FACTORS INFLUENCING SWEET POTATO IN SOUTH

EASTERN NIGERIA

Igwe C. O.K, Asumugha G.N, Igwe, K.C and Anyaegbunam H.N


[email protected]

Abstract Sweetpotato (Ipomoea batata L (lam)) is grown throughout the country for food and cash. It ranks second after cassava as a major root crops Nigeria. Both the young leaves and vine

tips serve as vegetables and are consumed by most households. Due to its wide adaptation to different environments, short maturity duration and its nutritional value and utilization value, it

serves in alleviating hunger during slack period. This paper is focused on factors influencing the production of sweet potato in Nigeria. Farmers were interviewed using structured

questionnaire complimented with interview schedule. One hundred and fifty respondents constitute the sample size for the study. Descriptive and inferential statistics were used to

ascertain the socio-economic factors as well as determinants of sweet potato production.

The result of our analysis showed that farm planting materials (vines) and their availability are the factors affecting the production of sweet potato in Nigeria.

Keywords: Analysis, factors influencing, sweet potato, South eastern Nigeria



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266

Determinants of farmers’ willingness to export yam in Ibarapa east and Ibarapa

central local government areas of Oyo State

Adesiyan O.F., Adesiyan A. T., Yesufu, O. A. and A. L Lasisi

Department o f Agricultural Economics

Obafemi Awolowo University, Ile-Ife , Nigeria

[email protected]

+2348035138766

Abstract The study was carried out to determine the factors affecting farmer’s willingness to export yam in Oyo state. Oyo state was particularly chosen because it is one of the states that rank

high in the production of yam in South-west Nigeria. This study used data collected from a multistage sampling of 80 yam farmers covering two Local Government Areas, Ibarapa East

and Ibarapa Central Local Government Areas. The data was collected through the aid of well-structured questionnaire using multi stage sampling technique and analysed using

descriptive statistics and probit model. The results showed that majority of farmers in the study area are ageing, with a mean age of 57.21, it was also observed that there were more

males (87.5%) than females (12.5%) that grew yam in 2010/2011 cropping season and also percentage of farmers with formal education was high (71.2%). 88.8% of the respondents

indicated lack of finance as a constraint to exporting yam. The result of probit analysis

showed that farm size (0.81, p = 0.002) was the only significant factor determining the willingness of farmers to export. This means that as the farmer’s farm size increases so also

is their willingness to export yam. It was also observed that farmers who had other occupation (0.96, p = 0.154), though not significant, was positive, meaning that farmers who had other

sources of income are more willing to export yam than their counterparts who are fully into farming. It was therefore concluded that farmers in the study area will be willing to export

yam if more land is made available and there is credit support. The study therefore recommends

to private investors, Non Government Organisations, research institutes and the government, to assist the farmers in the study area by making more land and credit available for yam

production so as to promote exportation of yam in Oyo State.



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267

Impact and adoption of value added innovations in root and tuber crops among

farmers in cross river state, Nigeria.

Aniedu, C., Aniedu, O. C. and Nwakor, N.

National Root Crops Research Institute (NRCRI), Umudike, PMB 7006,

Abia State, Nigeria.

Phone: +234 (0)803 5426 787 or +234 (0) 802 6974 728

[email protected]

Abstract

The National Root Crops Research Institute (NRCRI), Umudike embarked on massive training and extension of technologies of new and improved food forms of root/tuber crops to rural farmers/women groups from 2005 to date in Nigeria generally and in South-eastern and

South-south parts in particular. However, the main purpose of this study is to determine the

impact and adoption rate of this training and extension activity among farmers in Cross River State of Nigeria. A structured interview schedule, administered to 90 farmers in 3 zones of

Calabar, Ikom and Ogoja was the major instrument used in data collection. The respondents were 30 generated from a particular training point in each zone. The data were analysed

using means, percentages and means scores. The result revealed that although the respondents were mostly women, an appreciable number of men participated in the training and these

respondents were reasonably aware of the innovations. However, the adoptions of the

innovations (value added products and cultivation) by the respondents were very low but had reasonable impact on the livelihood of the respondents as good proportion used them as food

and in receiving visitors at home, earned income from them and also acquired valuable information from the training. Also, tangible impact was made in the livelihood of the

respondents as income earned from the adoption of the innovations helped them in acquisition of more farmland, in paying school fees, and to a reasonable extent, in payment of medical

bills. This was adjudged as being contributory to the realization of some Millennium Development Goals (MDG). However, the major challenges associated with the adoption

were lack of funds, lack of equipment/facilities and lack of market respectively. Challenges

such as no retraining facilities, inadequate knowledge of the innovations and no extension worker to answer questions were also viewed as important. It is therefore recommended

that re-training with increased extension workers and provision of equipment and market facilities should be intensified to enhance the adoption and impact of these technologies

among the farmers. Key words: Adoption, impact, training, value added products, innovations, technologies.



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Analysis of the value chain of sweet potato and household food security in

Southern Benin

Abdul-Baaki Bankole 1, Patrice Y. Adegbola1, Arnauld K Aguemon2,

Esaïe Gandonou3

1 Agricultural Policy Analysis of National Institute of Agricultural Research of Benin (PAPA /

INRAB), 01 BP 128 Porto-Novo 2 Centre d’Action Régionale pour le Développement Rurale (CARDER)

Ouémé-Plateau, BP 81 Porto-Novo 3 Faculté des Sciences Agronomiques, Université d’Abomey-Calavi, BP 526 Cotonou

Contact Person: Ir. Abdul-Baaki BANKOLE. E-mail: [email protected]

Abstract The sweetpotato is one of the roots and tubers that can adapt and grow in various agro- ecological conditions. From a nutritional standpoint, it is an important source of food energy

and so contributes to the high human and animal nutrition, and thus food security in many parts of the world. Typically, it is grown as a reserve for the period known through welding,

which gives it a special value in food security. In Benin, its production has been increasing in recent years. The present study aims to promote a value chain of sweetpotato through

economic analysis, to identify its place in the food and analyze the level of household food security of farmers surveyed. To achieve this goal, data were collected in the townships of

Dangbo, Athiémé, Pobè and Klouékanmè belonging to the three agro-ecological zones that

make up the Southern Benin and market Ouando of Porto-Novo. Interview guides and structured questionnaires were conducted with 177 participants (farmers, collectors,

wholesalers, retailers). Economic analysis, test prioritization K Kendall and frequency analyzes were used to analyze the data. The analysis of these data showed the existence of two (02)

value chains of sweetpotato: the value chain of raw sweet potato for the local market and the value chain of raw sweetpotato to the under-regional market. Value chain raw sweet potato

for the local market (chain studied) generated a value added of 57.87 FCFA / kg for all the

links with participation in the creation of added value 42.73% for producers, 11.49% for the collector, 36% for wholesalers and 9.78% for retailers. In addition, analysis of the results

showed that the sweetpotato doesn’t have a privileged place in the daily diet of the respondents. It was ranked in the fifth position after maize, cowpea, cassava and rice. Finally,

it is clear from the analysis of the level of household food security of farmers that could end up in a situation of food insecurity has been a concern for nearly 40% of respondents and

12.5% of them seem to be affected by chronic food insecurity. So to reduce malnutrition in the population, we should increase investment in research to improve the products promoted

in order to make them comparable to cassava products.

Keywords: Value chain, Sweet Potato, Value added, Food Security, West Africa.



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How small-scale farmers learn from the market

Moses Matui1, Paul Ingenbleek1, Anita Linnemann2, Hans van Trijp1, Abass

Adebayo3

1Wageningen University, Marketing and Consumer Behavior (MCB), The Netherlands 2Wageningen University, Food Quality and Design (FQD), The Netherlands

3International Institute of Tropical Agriculture (IITA), Tanzania

Abstract

With the collapse of marketing boards in many African countries, the responsibility to make strategic decision on what crop to grow and where to market it appears to have shifted from

the government to small scale farmers. This can be attributed to market liberalization reforms

and the removal of constraints that hinders farmers’ access to market. With market constraints removed the window of opportunity for farmers to access market is widen with market

stakeholders such as NGOs and lead companies from market channels approaching farmers with market opportunities. Knowledge is lacking on how farmers deal with these increased

responsibility to make strategic market decisions and how they seize new market opportunities. This study finds that smallholders differ in their market capabilities to identify and seize

market opportunities and they also differ in their attitude towards learning from those

knowledgeable about the market. Based on these difference two categories of farmers are identified i.e. leaders (those who are emulated by others due to their ability to sense the

market and establish valuable relationships with the market) and followers (those who lack the capability to sense the market but are good in taking instructions or mimicking others).

Followers appeared to gather around one or a few leaders and by mimicking they were likely to produce commodities of same quality. Leaders appeared to defy sameness and instead

sought individual uniqueness by introducing new crops and markets or by seeking to outperform

others. Efforts by market intervention programs should take note of these differences and therefore seek to target leaders and followers differently. Failure to do so could result to

isomorphism (increased sameness among farmers) which market liberalization reforms seeks to address.


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270

Gender perception of climate change and adaptation among small-holder cassava

farmers in Anambra State, Nigeria

Madu, T. U., Okoye, B. C and Chinaka, C. C

National Root Crops Research Institute Umudike, Nigeria

[email protected]

Abstract

This work examined the gender perception of climate change and adaptation among small holder cassava farmers in Anambara. Three out of the four agricultural zones were purposively

selected for the study based on intensity of agricultural activities. They are Anambra, Awka

and Aguata zones. Multi-stage randomised sampling technique was adopted to select 120 cassava farmers disaggregated into 60 males and 60 females in 2010 for the study, relevant

data elicited from the farmers through structured questionnaire and analysed with descriptive statistics as well as 5 point likert scale measurement. Also multi-data gathering tools to obtain

information such as focus group discussion (FGD) involving adult males, adult females and the youth, using scheduled discussion guide, in-depth interview of key informants/opinion

leaders (such as the traditional ruler, president of the town union etc.) in the communities

using structured checklist. The result indicated that farmers were mainly middle aged, educated and very experienced

in farming and farming in the state is a female dominated occupation as about 62% of the farmers were females. The people are aware of climate change but the perception of climate

change did not differ among gender in the study area. It was observed that women and children (including the youth) are more vulnerable to the impact of climate change than adult

males. In order to respond positively to the negative impact of climate change farmers engaged

in a paradigm shift of farming activities.

Key words: Gender, Perception of climate change, Adaptation and Cassava farmers




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271

Optimum combination of major root crop based enterprises and resource

allocation by smallholder farmers in Abia State, Nigeria

K. C. Igwe1, C. E. Onyenweaku1, C. O. K. Igwe 2 and G. N. Asumugha2

1Department of Agricultural Economics, Michael Okpara University of Agriculture, Umudike, P.

O. Box 2, MOUAU Post Office, Umudike, Abia State, Nigeria

[email protected] 2Extension Services Programme, National Root Crops Research Institute, Umudike, P.M. B. 7006,

Umuahia, Abia State, Nigeria

Abstract

The study examined optimum combination of selected root crop based enterprises and resource

allocation of smallholder farmers in Abia State, Nigeria using the linear programming approach. The objective function was to maximize total gross margin of producing major root crop

based enterprises less costs of labour and marketing. A multi-stage random sampling technique was used in data collection from 60 smallholder farmers in the state using the limited cost

route approach. Crop production and product selling activities were incorporated in the LP

model. Crop production activities comprise sole crops and crop mixtures. Resource allocation was compared between land owners and tenants with the aim of investigating their relative

competitiveness in major root crop based enterprise combination. Generally, results showed that the sampled farmers were not optimal in their resource allocation. Yam based and cassava

based enterprises dominated the existing plan. Optimal farm plans favoured fewer crops than in the existing plan. Major root crop mixtures were more competitive than the sole root

crops, which give indication to the economic orientation and subsequent growth in the study

area. This is because farmers’ purchasing power would be enhanced given optimal enterprise combination and resource allocation.

Keywords: Optimum enterprise combination, major root crops, linear programming,

smallholder farmers, Abia State, Nigeria



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272

PATHOLOGY

Community Phytosanitation: Progress in Cassava Brown Streak Control through Clean Seed

K.J.Mtunda1, I. Ndyetabura2, J. Legg3, J. Ndunguru4, A. Mwenisongole 1,

F.Kaminyoge5, I. Lwabuti6, and E. Shumbusho7

1 Sugarcane Research Institute, P.O. Box 30031, Kibaha, Tanzania

2 Agricultural Research Institute-Maruku, P.O. Box 127, Bukoba, Kagera, Tanzania

3 International Institute of Tropical Agriculture, P.O. Box 34441, Dar es Salaam, Tanzania

4 Mikocheni Agricultural Research Institute, P.O. Box 6226, Dar es Salaam, Tanzania

5 VECO East Africa, P.O. Box 105516, Dar es Salaam, Tanzania

6 Rulenge Diocesan Development Office, Ngara, Tanzania

7 KOLPING Society of Tanzania, P.O. Box 1236, Bukoba, Kagera, Tanzania

Project leader contact e-mail: [email protected]

Abstract

Cassava brown streak disease (CBSD) is among the principal biotic stresses that threatens cassava productivity in Tanzania. The disease reduces opportunities for value addition and increases labour

for women who have to remove necrotic tissues from affected roots. The cassava brown streak viruses (CBSVs) that cause CBSD are transmitted by a whitefly vector, Bemisia tabaci, as well

as through planting cuttings from infected mother plants. Recent research into the transmission of CBSVs by whiteflies has shown that the virus particles are not very efficiently retained by these

insects, meaning that CBSD spreads over relatively short distances. This opens up the possibility

for controlling CBSD through careful management of the health of cassava plants (phytosanitation). Three key elements of phytosanitation that can be used to control CBSD include: establishing

crops using healthy planting material, maintaining the health of cassava crops during the active growth period, and avoiding to plant healthy cassava cuttings near to diseased cassava crops.

In Tanzania, a ‘Community Phytosanitation’ approach to managing CBSD is being tested at a pilot level in communities in two of the major cassava-growing agro-ecological zones. The

aim of this research is to demonstrate that it is possible to greatly reduce the overall incidence

and consequent impact of CBSD by implementing a community-wide phytosanitation programme. The progress made so far includes: i. Situational analysis at community level

through a baseline survey; ii. Mapping of cassava farm families to understand the varieties grown, size of the fields and households; iii. Sensitization and awareness creation at district,

ward, village and community levels; iv. Training of extension staff, community leaders and



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273

farmers; v. Formation of disease control committees at community level to act as a task force and to develop rules and regulations to prevent disease spread; and vi. Multiplication of

clean planting material for distribution to farmers. A key lesson of year one has been that

bulking of clean virus-tested planting materials is a pre-requisite for the success of the approach. Similarly, effective implementation by community members relies on awareness creation at

local level on the symptoms, causes, effects and control measures for virus diseases of cassava. In order for this to be achieved, effective community-level training for all stakeholders

is required. Although the community phytosanitation programme is at an early stage, it is expected that CBSD incidences will be reduced and contribute to increased productivity of

cassava in the target villages. Implementing partners include the Department of Research and Development, the Ministry of Agriculture Food Security and Cooperatives, the International

Institute of Tropical Agriculture, the Tanzania Official Seed Certification Institute, VECO

Tanzania, KOLPING Society Tanzania, Rulenge Diocesean Development Office, and Local Government Authorities in respective districts.


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274

Occurrence of sporadic dry root rots caused by Phaeolus manihotis Heim

(Basidiomycete; Polyporaceae) on cassava in the Bas-Fleuve district of DR

Congo and attempts for its control

Kassongo W. Tata Hangy, K. Bambala, S. Nluta, Lyna Mukwa

and Nzola M. Mahungu IITA-DRC, 4163, Avenue Haut-Congo, Commune de la Gombe, KINSHASA


Abstract

In 2009 severe dry root rots were observed in cassava farms in the secondary forest areas

of Kimbianga and spread all around the Lukula territory of the Bas-Fleuve district. A strange yellowish mushroom that was identified as Phaeolus manihotis Heim was associated with

the rots. P. manihotis is known as a latent species in most of the secondary forests of Africa. Preliminary investigations initiated by IITA’s cassava project in DRC indicated that all cultivated

varieties, including those resistant to the cassava mosaic disease (CMD)which were introduced and disseminated in the area in early 2000s, were affected, but at variable degrees. In the

attempts to stop the spread of the disease, as response to the local government’s call of

intervention some works were undertaken. First, fungicide applications using benlate systemic fungicide, in order to halt the spread of the disease, were tested. The fungicide was sprayed

in the soil at planting around the cutting and thereafter around the plant at monthly basis for 3 months. The 2 treatments were compared to no fungicide application treatment. Results of

the tests showed that the fungicide applied at planting only didn’t really stop the development of P. manihotis on the crop; but when applied monthly for 3 months, the fungicide reduced

the incidence of the root rots by 80%. The overall average of the rots, all varieties put

together was 29.4% when the fungicide was applied at planting and only 0.4% when the fungicide was applied monthly for 3 months.

In addition, factors that were supposed to be responsible as source of contamination and mode of propagation of the disease were assessed in another trial. The source of contamination

was measured using cuttings from plants that showed root rots in the previous cropping season and those which did not show any root rots, thus healthy plants. Also, 2 types of plots

were considered: (a) a plot where cassava was planted just after cassava as previous crop;

and (b) a 2-year fallow plot. Three best varieties resistant to CMD were used to evaluate the treatments. They were; Lueki reported to be susceptible to the rot disease, Disanka, observed

to be tolerant and Nsansi one of the preferred varieties. The analysis of the data collected showed no statistical differences in the root rots incidence between the treatments measured.

At the end of the experimental period, P. manihotis became less frequent than the previous seasons.

Further research is needed to understand the reasons of sporadic occurrence of the P.

manihotis in DRC.



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275

In vitro inhibition of fusarium by Lactic Acid Bacteria (LAB): Implication of yam

disease control for economic growth in Nigeria

Omodamiro1, R.M, Ojimelukwe 2, P.C, Asiedu3, R and Omodamiro2, O.D

1National Root Crops Research Institute, Umudike.Nigeria2Micheal Okpara University of

Agriculture, Umudike and 3 International Institute of Tropical Agriculture, Ibadan.Nigeria

[email protected]

Abstract

Yam is an important crop in Nigeria, where it is produced both as food and cash crop. Fusarium rot of yam is among the most important postharvest pathogens of yam worldwide, causing a lot of postharvest losses in stored yam tubers. Lactic acid bacteria (LAB) lower

the pH and create an environment that is unfavorable to pathogens and spoilage organisms.

In vitro inhibition of fusarium spp by LAB was investigated using mono-culture and multi- culture. The inhibition tests were carried out with pure cultures of LAB and fusarium spp.

The pure culture of actively growing Fusarium was used to inoculate Potato Dextrose Agar medium aseptically and then incubated at room temperature for 72h. The diameter of the

growing Fusarium was measured after which less than a loop full of actively growing (18- 24h) LAB isolates were used to inoculate the medium containing the growing Fusarium at a

known distance in the same plate. The whole set up was incubated at 300C and inhibition zones on Fusarium by the LAB were observed 24hourly for 96h. The tests were carried out

for mono-culture and multi-culture in triplicate. The inhibition zone ranged from 43 to 100%

in mono-culture plate and 40 to 113% in multi-culture plate, respectively. The slightly larger inhibition in the multi-culture plate may be attributed to higher pressure on the Fusarium.

Hence, LAB may be used to control rot caused by Fusarium in stored yam thereby improving yam tuber storage for better economic growth.

Key words: Yam, Lactic acid bacteria, Fusarium, inhibition and postharvest.




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276

Effect of different stake portions on cassava mosaic disease expression and yield

of three cassava varieties under natural field infection

I. A. Smith,O.O Aina, E. Y. Parkes, P. O. Iluebbey, A. Agbona, I. Y. Rabbi, M.

Gedil. P. A. Kulakow International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria, [email protected]

Abstract

Cassava mosaic disease (CMD), caused by geminiviruses, is the most severe disease of cassava in West Africa. It often spreads through infected cuttings. Therefore, there is a need

to identify the portions of the stem most suitable for planting materials that minimize disease

symptoms and produces good root yield. Two factors studies included genotypes and stem portions use in planting. The three cassava genotypes varied in CMD resistance: susceptible

(TMEB117), moderately resistant (IITA-TMS-IBA30572) and resistant (TMEB3). Stems were divided into 3 sections consisting of the hardwood, semi-hardwood and green shoots. A

3 x 3 factorial experiment used a randomized block design with four replications. Stems were cut into 20cm planting sizes and established at IITA, Ibadan on ridges spaced 1m apart with

five plants spaced 0.8m apart within rows. Data was taken on disease incidence and severity,

growth and yield. Cassava mosaic disease was evaluated at seven times including 2 weeks after planting followed by 1, 2, 3, 4, 5 and 6 months after planting. Analysis of variance

(ANOVA) revealed significant effects among stem portions and genotype. Hardwood had the highest CMD severity (mean score 3.28) while the upper shoots or green portion recorded

the lowest severity (2.80). The upper shoot portion had the lowest vigor (4.42), root number (16.54) and fresh root yield (8.9t/ha). The hardwood and semi hardwood portion were not

significantly different for most of the parameters. Semi-hardwood recorded the highest fresh

root yield (12.5t/ha) followed by hardwood (11.34t/ha). TMEB117 had the highest CMD severity (4.05) and incidence (0.94), while TME3 had the lowest severity (1.75) and incidence

(0.25). TMEB3 had the highest root yield (13.98t/ha) and root size (5.92), while TMEB117 had the lowest root weight (8.14t/ha) and root size (4.42). The semi-hardwood was identified

as the best stem portion for cassava establishment.

Key words: cassava mosaic disease, planting material quality, cassava



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277

Evaluation of four plant extracts in the control of post-harvest tuber rot of Irish potato (Solanum tuberosum)

Ogunsola J. F1 and Aduramigba-Modupe A. O1*

Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria. * [email protected]

Abstract

This study was conducted to isolate and identify pathogens associated with Irish potato post- harvest tuber rot and evaluate the efficacy of some plant extracts in vitro and in vivo in the control of Irish potato rot-causing pathogens. One hundred rottened Irish potato tubers were

collected from Bodija, Sabo, Apata and Gariki (Abuja) Market. Fungi were isolated from

rotted potato tuber samples identified using culture and morphological characteristics. Four plant extracts namely Zanthoxylum zanthoxyloides roots, Distemonathus benthamianus

stems, Morinda lucida and Moringa oleifera leaves were evaluated against Botryodiploidia sp., and Fusarium verticilloides using three (500, 1000 and 1500mg/ml)

concentrations. Nine fungi species associated with Irish potato tuber rot were identified in this study. Fusarium oxysporium had the highest frequency of occurrence in Bodija market

followed by Fusarium verticilloides. F. verticilloides had the highest frequency of occurrence

in Sabo, Abuja and Apata market. There were significant differences (Pd”0.05) in the rot induced by fungi which range between 7.07 – 87.55%. Botryodiplodia sp, Fusarium

verticilloides, Macrophomina sp., Fusarium oxysporium, Penicillium digitatum, A. niger, Phoma sp., were found to cause post-harvest rot on Irish potato. Growth inhibition of rot

causing organisms in vitro varied with extract type, concentrations and pathogens. D. benthamianus extract was the most effective in vitro and in vivo of the four extracts

evaluated. Morinda lucida and Moringa oleifera extracts inhibited Botryodiplodia sp. at

1500mg/ml concentration producing 16.67% and 16.27% inhibition respectively. Both extracts inhibited Fusarium verticilloides at all concentrations. D. benthamianus could serve as

an alternative to synthetic chemical in controlling post-harvest tuber rot of Irish potato. However, this botanical should be further evaluated for its control of the potato rot-

causing pathogens in storage as well as any side effects on potato quality especially taste.

Key word: Irish potato tuber rots, Distemonanthus benthamianus, Moringa oleifera, Zanthoxylum zanthoxyloides, mycelial growth inhibition,



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278

Effect of some plant extracts and pesticides in the control of Bacterial Leaf Blight disease of Colocasia esculenta caused by Xanthomonas campestris in Umudike,

Abia State Nigeria

Opara, E. U.1, Isaiah, E. C. 1, Eze, E. C.1, Okolo C. C.2, Ezeaku, P. I2., Chukwudi,

P. U.* 3, Ezeudo, V. C.2, Osadebe, V. O.3, Okechukwu, E. C.3, Amuji, C. F.3 and Imegwu, C.3

1 Department of Agronomy, Micheal Okpara University of Agriculture Umudike, Abia State 2 Department of Soil Science, University of Nigeria, Nsukka, Enugu State

3 Department of Crop Science, University of Nigeria, Nsukka, Enugu State

* [email protected]

Abstract

A pot trial was conducted in the screen house of National Root Crops Research Institute (NRCRI), Umudike to determine the efficacy of some plant extracts and pesticides in the

control of bacterial leaf blight of cocoyam (Colocasia esculenta). The treatments employed include: Lemon grass (Cymbopogon citrates), Black pepper seed (Piper guineense), orange

peel (Citrus sinensis), streptomycin sulphate (bactericide), copper oxychoride (fungicide) and sterile water (control). The experiment was laid in complete randomized design (CRD)

and replicated six times. The materials used were first made into cold water aqueous extracts and diluted to 10% concentration (w/v). Application on leaves were made using hand sprayer

at two weeks interval. Data obtained showed that Citrus sinensis peel had the least disease

score (1.17cm) which differed significantly from the rest of the treatments at P d” 0.05, it was followed by piper guineense (1.33cm). All the extracts tested proved superior to the

control (sterile water) and were at a par with the two pesticides tested. Copper oxychloride gave 1.67cm and streptomycin, 1.83cm in reducing disease and enhancing yield better than

the control but different from the extracts.



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279

Field response of pacific accessions of Colocasia esculenta to taro leaf blight

disease in Nigeria

Onyeka T. J. *, Ezeji L., Chukwu, G., Amadi, C., Okoye B. C. and Mbanaso,

E.N.A. National Root Crops Research Institute (NRCRI) Umudike, Nigeria.

*E-mail: [email protected]

Abstract

Leaf blight caused by Phytophthora colocasiae is the most important disease of taro (Colocasia esculenta) globally. Taro leaf blight (TLB) is a new disease in Nigeria and other

West African countries with an estimate economic loss of about 1.4 billion US dollars annually in addition to potential genetic erosion in taro gene pool in the sub-region. The use of resistant

varieties offers the most sustainable management strategy. However, such varieties are not immediately available, and the genetic diversity of existing taro cultivars in Nigeria is rather

low for efficient breeding purpose. A total of twenty-five taro accessions introduced from the Pacific for breeding purpose in Nigeria were evaluated and compared to five local cultivars

for field response to TLB. The results indicate that high variation for TLB response exists

among the introduced Pacific accessions. The twenty-five introduced accessions were separated into four response groups based on the mean percentage plant area infected.

Three accessions performed comparatively better than others with d” 20% of plant area infected throughout the period of the study. Compared to the local cultivars, about 17 of the

introduced accessions tested (68%) performed better than the best local cultivar. Further studies are on-going on the agronomic traits of these accessions and that possible utility in

genetic improvement for TLB management in Nigeria.



(ISTRC-AB)

Traditional dried yam ‘gbodo’, using molecular techniques

1Joan M. Babajide, 2Robert Skilton, 2Solomon Maina, 3Gbenga Adewumi, and 1Funmilayo Adeniran

1Department of Food Science and Technology, Federal University of Agriculture, Abeokuta,

Nigeria. 2Bioscience Eastern and Central Africa – International Livestock Research Institute

Hub, Nairobi, Kenya. 3 Department of Food Science and Technology, Bells University o f

Technology, Ota, Nigeria.

[email protected]

Abstract

‘Gbodo’ is a traditional fermented food prepared from dried yam tubers or slices. The flour when stirred in boiling water makes a paste commonly consumed with vegetable stew by the

West Africans. The microbial population of gbodo has been studied using microbiological analysis. This study focuses on the use of molecular techniques to identify new fungi isolates

present at the fermentation stage of gbodo production. The identification of bacteria isolates

are reported in subsequent work. Seven pure cultures of fungi were isolated from yam steep water during the steeping stage of gbodo production; these were identified using molecular

techniques. CTAB (hexa decyl trimethyl ammonium bromide) method was used for genomic DNA extraction from pure cultures of fungal isolates and each genomic DNA extract was

amplified by polymerase chain reaction (PCR) using fungal specific primers (Internally Transcribed Spacer, ITS1, and ITS4). The PCR products were purified and sequenced and

the data analyzed using CLC Main Workbench. The sequence of each sample was identified

by NCBI database. Validation of identity was confirmed using the BOLD system database for Barcoding ITS region followed by multiple sequence alignment and phylogenetic analysis.

Six isolates were confirmed as Meyerozyma guilliermondii and one other as Cladosporium cladosporioides - each matched 100% identity with E-value of 0 respectively. These fungi

are Ascomycota, and M. guilliermondii was identified as one of the fermenting organisms in yam steep water with other industrial importance in dough fermentation and biocontrol

storage system.

Key words: yam steep water, molecular techniques, ITS gene, phylogenetic analysis,

Meyerozyma guilliermondii .

280



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281

Molecular-based diversity of the scale insect Stictococcus vayssierei in the Congo

Basin: evidence of the existence of a species complex

Armand Doumtsop1, 2, Rachid Hanna1, Abraham Fomena2, Benjamin Normark3,

and Willy Tata Hangy4

1International Institute of Tropical Agriculture, B.P. 2008-Messa Yaoundé, Cameroon,

[email protected]; 2Faculty of Sciences, University of Yaoundé I, Cameroon; 3 Department of

Plant, Soil, and Insect Sciences, University of Massachusetts, USA; 4IITA-DRC, Kinshasa, DR

Congo.

Abstract

The African root and tuber scale (ARTS) Stictococcus vayssierei is an indigenous pest of cassava in the Congo basin. This species has been considered since its description as the

only underground scale of the family Stictococcidae. Recent preliminary evidence of several geographic populations of the scale suggested, however, that there are likely cryptic species

in this pest group, complicating the evaluation of host plant resistance and other options for the control of this species. In this study, mtDNA COI/COII and rRNA subunit 28S genes

were used to characterize S. vayssieres specimens originating from 13 host plants and 127 localities in five countries including Cameroon, Central African Republic, Democratic Republic

of Congo, Equatorial Guinea, and Gabon. In this study, the scale was not found in Southeastern

Nigeria where a new species of Stictococcidae was recently reported. Gene sequence divergence ranged between 0 and 4% in rRNA 28S and 0 to 3.2% in mtDNA COI/COII

genes. The highest sequence divergence occurred within Cameroon populations. Specimens from Northwest Cameroon showed the highest between-group mean distances of > 2% and

> 13% divergence with 28S and COI/COII genes, respectively There was, however, little association between scale genotype and host plant. The presence of genetic diversity in S.

vayssierei complex supports the evidence of the existence of one distinct species and at

least five cryptic species. Implications of these findings for S. vayssierei management in cassava fields in Central Africa will be discussed.

Keywords: Cassava, molecular analysis, mtDNA COI/COII, cryptic species.



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282

Boric acid for the suppression of the ant, Anoplolepis tenella and impact on

infestations of its tended scale insect, Stictococcus vayssierei in cassava fields

Apollin F. Kuate 1, Rachid Hanna1, Samuel N. Nanga1, Maurice Tindo2 and Peter

Nagel3

1International Institute of Tropical Agriculture, B.P. 2008-Messa Yaoundé, Cameroon,

[email protected]; 2Department of Animal Biology, Faculty of Science, University of Douala BP

24157, Douala; 3Department of Environmental Sciences, Biogeography Section, University of

Basel, St. Johanns-Vorstadt 10, 4056 Basel, Switzerland.

Abstract

Anoplolepis tenella is the ant species frequently associated with the proliferation of the cassava pest Stictococcus vayssierei in Central Africa. Amdro, Borax and Boric acid solution

were evaluated in the laboratory for toxicity against A. tenella colonies. Workers were exposed to bait for ten days during primary screening and colonies for six weeks during secondary

screening. Mortality was recorded daily. Results indicated that each of the three toxicants studied delayed toxicity with less than 15% mortality after the first day. In comparison to

Amdro and Borax, 1% Boric acid was more effective in killing ant workers. Boric acid- sucrose solution reduced the numbers of workers and brood by 90% within 6 weeks. In a

field experiment carried out in southern Cameroon for 12 months, the effect of Boric acid

and sugar offered in home-made bait station was evaluated in four cassava field. Monthly ant and scale sampling showed significant reduction of ant density in treated fields during the

first five months, which resulted in a reduction of scale infestation on cassava. Scale infestation was higher on the local variety Mevini compared to the improved variety IITA TMS 96/0023.

We noted 16.1% higher cassava yield in treated compared with control plots. These results outline the dependence of S. vayssierei survival on A. tenella attendance and demonstrate

that control in cassava fields can help in developing control options for the scale in central Africa.

Key words: Amdro, Ant control, Borax, Cameroon, IITA TMS 96/0023, toxic bait.



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283

Characterization of microorganisms isolated from cassava peel wastes

Gbenga Adedeji Adewumi1, Olusola Bandele Oyewole 2

1Dept. of Food Science and Technology, College of Food Sciences, Bells University of

Technology, Ota, Nigeria 2Dept. of Food Science and Technology, College of Food Sciences and

Human Ecology, Federal University of Agriculture, Abeokuta, Nigeria 1gbenga_adewumi2007@yahoo .com

Abstract

In this study, the microorganisms associated with cassava peel wastes were characterized and identified phenotypically. Cassava peel wastes were obtained from a popular Gari processing unit within Abeokuta metropolis under aseptic condition. pH of the homogenate

was determined and found to be 4.18, moderately acidic. Diluents of appropriate decimal

dilutions were spread-plated on nutrient agar (NA) and potato dextrose agar (PDA). Fifteen bacterial representative isolates were recovered and analysed for colonial, morphological

and biochemical characteristics. They were identified as Bacillus spp., Micrococcus spp., Planococcus spp., Deinococcus spp. and Pseudomonas spp. The fungal isolates were

identified as Rhizopus spp., Aspergillus niger, A. oryzae and Saccharomyces cerevisiae. The diversity and functional potentials of the microflora of cassava peel wastes as revealed

in this study can aid the conversion and utilization of cassava peel wastes for various industrial purposes such as glucose production, organic acids and single cell proteins among others.

This can help to reduce the alarming increasing problem of cassava peel wastes disposal.



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284

Initiatives by IITA to pre-empt cassava diseases and climate change to enhance

food security in Burundi and Rwanda

Emmanuel Njukwe 1, Ntawuruhunga Pheneas2, Bigirimana Simon3 and Gashaka

Gervais4

1International Institute of Tropical Agriculture (IITA) Bujumbura, Burundi; Email:

[email protected] 2International Institute of Tropical Agriculture (IITA) Lilongwe, Malawi ; Email:

[email protected] 3Institut des Sciences Agronomiques du Burundi (ISABU) Bujumbura, Burundi ; Email:

[email protected] 4Rwanda Agricultural Board (RAB) Kigali, Rwanda; Email: [email protected]

Abstract

Over 40 million people in East and Central Africa eat the starchy roots and nutritious leaves of cassava meanwhile cassava. Unfortunately, this important crop is being ravaged by two

diseases- Cassava Mosaic Disease (CMD) and Cassava Brown Streak Disease (CBSD) with the potential to reduce yields by over 70% and render the roots and leaves inedible.

These diseases have led to severe food insecurity in Burundi and Rwanda and further aggravated by increasingly degraded environment and the uncertainties resulting from climate

change. Such declining and variable environments require robust crops adapted to a wide range of agro-ecologies and cassava is a choice crop for such situation. Unfortunately, most

cultivated varieties are susceptible , making it necessary to introduce new varieties and

improving the cassava production system can be a pathway to food security and adaptation to climate change. In recent years, the International Institute of tropical Agriculture (IITA)

has used conventional breeding methods to produce improved varieties, with multiple resistance to disease, pest, and drought, low cyanide content, short crop cycle, and high yield. Such

improved varieties constitute environmentally sound and economically efficient options for combating pest and diseases. We therefore embarked on introduction of seven improved

cassava varieties (MM06/0138, MM06/0082, MM06/0143, MM06/0046, MM06/0130, MM06/

0074, MM06/0013) in collaboration with the plant health regulatory services of Burundi and Rwanda for participatory evaluation. This initiative will build-on and complement on-going

and completed research on cassava focusing on the multiplication and distribution of CMD resistant varieties while taking care not to inadvertently distribute CBSD within planting

materials. Combating CMD and CBSD will also require the initiation of stakeholders’ platform for appropriate knowledge sharing and collective action which is an important and integral

component. Wide-scale cultivation of improved cassava varieties in Burundi and Rwanda

may contribute to a sustainable production for food and income security for the population.

Key Words: Cassava, climate change, food and income security, host plant resistance,

stakeholders’ platform






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285

Pests and diseases status of local and improved cassava genotypes in selected

pilot sites in Cameroon

Maurice Tindo1,*, Emmanuel Njukwe 2 and Abdou Tenkouano3

1University of Douala, Faculty of Science, Department o f Animal Sciences, B.P. 24157

Douala, Cameroon 2International Institute of Tropical Agriculture, Burundi Station, B.P. 1893 Bujumbura, Burundi

3AVRDC-The World Vegetable Center, Bamako, Mali *Maurice Tindo, c/o International Institute of Tropical Agriculture, Cameroon Station, BP 2008

Messa, Yaoundé, Cameroon,

* [email protected].

Abstract

We conducted two main surveys during dry seasons in 29 sites within the five antennae of the “Programme National de Développement des Racines et Tubercules” (PNDRT) Cameroon to assess potential changes triggered by the introduction of the improved genotypes

on cassava pest and disease status. Standard methods were used to evaluate pest incidences,

population and damages, natural enemies’ occurrences, diseases incidences and damages severities on both local and improved varieties. Seven predominant pests were found damaging

cassava plants including the cassava mealy bug (CM), cassava green mite (CGM), red mite (RM), white fly (WF), spiralling white fly (SWF), the African root and tuber scale (ARTS)

and the variegated grasshopper. The incidence, number of individuals and damages severities of all pests varied considerably between survey dates, antennae and varieties but were

controversial. Natural enemies of CGM were observed but not in all the antennae. Symptoms

of six diseases were observed in cassava fields including cassava mosaic disease (CMD), cassava anthracnose disease (CAD); cassava bacterial blight (CBB), cassava root rot (CRR),

brown and white leaf spot. The incidence and severity of diseases also varied considerably between antennae, sites and cassava varieties. Their severities were generally mild to

moderate. In general, improved genotypes were significantly resistant to CMD, CBB and CAD diseases than local material. Taking all these results together, one can conclude that

although the introduction of improved cassava genotypes is not significantly affecting the

cassava pest status, it is significantly reducing the CMD effect while both local and improved genotypes are still attacked by other diseases like CAD and CBB. Effort should therefore

continue to develop, select and introduce resistant material against major pests and diseases. An overall review of the cassava health management in Cameroon is provided.

Key words: Cassava mosaic disease, green mite, predatory mite, IMP



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286

Identifying Cassava Mosaic Disease Resistant genotypes for industrial and local

uses In Sierra Leone.

A.E.Samura1., F.B. Massaquoi., L.Kumar3., J.P.C Koroma2., M.T.Lahai2.,

S.N.Fomba1 and A.G.O. Dixon1

1 Sierra Leone Agricultural Research Institute 2 Njala University

3International Institute of Tropical Agriculture (IITA)

Abstract

The cassava mosaic disease is one of most economically important diseases that affect cassava with a high prevalence, incidence and severity among cassava genotypes in Sierra

Leone. Recent studies have detected the East African Cassava Mosaic virus in Sierra Leone. Currently released varieties for industrial purposes do not specifically meet the needs of

farmers who utilize cassava for domestic purposes. Non-domestic use of released varieties is responsible for the low adoption rate of improved cassava genotypes. This study was

undertaken with farmers’ participation to screen and identify promising and acceptable cassava genotypes with resistance to mosaic disease that meet industrial as well as farmers’

expectations.. One hundred local varieties and 2000 introductions from 29 families obtained

from IITA were screened for field resistance to cassava mosaic disease, farmers’ desired traits and industrial traits at Njala Foya crop site. Cassava families reacted differently to the

African Cassava Mosaic Disease (ACMD). Susceptible cassava families to ACMD had favourable qualities such as poundability, high protein and beta carotene which may be

incorporated into resistant genotypes that lack such qualities in the breeding programmes. Yield estimates of some of the selected cassava genotypes ranged between 22 t/ha to 48t/

ha. Some selected cassava genotypes possessed high dry matter content ranging between 30 and 52.2%. Hundred potentially adoptable cassava genotypes selected by farmers were

further categorized into industrial cassava, suited for gari, starch, high quality cassava flour

and sweet cassava suited for domestic consumption.


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287

Comportement de variétés de manioc en diffusion et en développement à

l’infestation par la cochenille africaine des racines et tubercules Stictoccocus

vayssierei Richard (Hemiptera: Coccoidea) dans le Nord Kivu

N. Eleko1 ; K M. Lema1 ; R. Hanna2 ; Mahungu3 N M

1 Université de Kinshasa/Faculté des Sciences Agronomiques;

2 International Institute of Tropical agricultural, BP 2008 (Messa) Yaoundé/Cameroun;

3 International Institute of Tropical agricultural, Kinshasa/RDC

[email protected]

Abstract

Cassava is, economically, one of the most important root and tuber crops in Africa. However, its production is constrained by a large number of diseases and pests among which the

African Root and Tuber Scale (Stictococcus vayssierei Richard) known as ARTS is of economic significance. This study was conducted in the administrative Territory of Beni,

North Kivu province, in East of the Democratic Republic of Congo. Surveys on cassava diseases and pests were conducted prior to experiments. The results of the surveys indicated

that ARTS causes enormous damage to cassava and other crops such beans, soybeans, Irish potatoes and many more uncultivated plants in the Cameroon. Screening data revealed that

most of the 35 released and yet to be released cassava varieties evaluated were susceptible

to S. vayssierei, Nerverthess, some level of tolerance was observed in improved varieties DISANKA (I 96/0211), BUTAMU (MV99/395), LIYAYI (MM96/0287), OBAMA (TME

419), and yet to be released varieties such as 20B2, 20B27, MM96/4649 and MM97/2206. Although ARTS was present, the yields of these varieties varied from 35 to 80 tons per

hectare. Mukalasa and Balulu are two other local varieties susceptible to ARTS, but which recorded impressive yield levels. The yields of these local varieties varied from 20 to 25

tons per hectare. The different results obtained indicated that the introduction of improved

cassava varieties could be one of the alternatives for ARTS integrated management. Also, results indicated that research, particularly variety development was essential for the

development of the cassava subsector.

Key word: Ants, altitude. Cassava varieties, harvest index, host plants, S. vayssierei.

Le manioc est l’une des principales plantes à racines de grande importance économique

cultivées en Afrique. Cependant, sa production est compromise par de nombreuses contraintes parmi lesquelles la cochenille Africaine des racines et tubercules Stictococcus vayssierei

Richard, un ravageur du manioc et d’autres plantes cultivées. Cette cochenille cause des dégâts pouvant aboutir au non tubérisation du manioc en cas d’infestation sévère. La présente

étude a été réalisée dans le territoire de Beni, à l’Est de la RD Congo. Elle avait été précédée par une enquête ménage sur les maladies et les ravageurs de manioc. Dans les essais en

milieu paysan, nous avons évalué la résistance à la cochenille de 35 variétés de manioc en

diffusion et en développement fournies par l’IITA et l’INERA et cinq variétés locales trouvées



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288

sur place. Ces variétés ont été installées dans quatre sites des moyennes (800-1000 m) et hautes altitudes (1200-1400 m) ayant des taux d’infestation variables. Les populations de la

cochenille aux différents stades de vie, la croissance de la plante et les rendements en racines

tubéreuses, le nombre de racines tubéreuses et les indices de récolte ont été évaluées tous les trois mois pendant 24 mois dans un dispositif expérimental en blocs casualisés avec

quatre répétitions. Les résultats de l’enquête ménage sur les maladies et ravageurs de manioc ont indiqué que les cochenilles causent d’énormes dégâts, suivi de ceux causés par la mosaïque

et pourriture des racines du manioc. L’enquête a également permis d’observer que les dégâts de la mosaïque sont différents d’un secteur à un autre et ont des effets significatifs sur les

autres maladies et ravageurs observés dans le territoire de Beni. Aussi plusieurs espèces hôtes de S. vayssierei ont été dénombrées telles que Haricot, Soja, Pomme de terre, Patate

douce, le palmier à huile, Igname, Caféier, Macabo, Arachide et les espèces sauvages comme

celles identifiées précédemment au Cameroun.Les résultats du criblage montrent que S. vayssierei a infesté la majorité des variétés testées. Toutefois, nous avons enregistré une

tolérance vis-à-vis de la cochenille chez certaines variétés en diffusion et en développement à l’instar des variétés DINSAKA (I96/0211), BUTAMU (MV99/395), LIYAYI (MM96/

0287), OBAMA (TME419) et autres variétés en développement telles que 20B2, 20B27, MM96/4649 et MM97/2206. Ces dernières variétés ont donné les meilleurs rendements

allant de 35 à 80 t/ha bien qu’étant infestées. Aussi, certaines variétés locales telles que

MBAYILO, MUKALASA et BALULU se sont bien comportés du point de vue production malgré leur sensibilité aux maladies et cochenilles radicoles de manioc, en produisant

respectivement 25, 21 et 20 tonnes ha-1 des racines tubéreuses. Nos résultats montrent que l’introduction des nouvelles variétés en milieu paysan pourraient être une alternative à la lutte

contre la cochenille et révèlent une importance majeure en amont de la filière de mise au point des variétés résistantes à S. vayssierei par les généticiens. Egalement la vulgarisation

des variétés tolérantes retenues dans la présente étude s’avère nécessaire dans les provinces

de l’Est de la RDC.

Mots Clés: manioc, S. vayssierei, altitude, Fourmis, ravageurs, plantes hôtes, indices de récolte.


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289

Management of sweetpotato weevil, Cylas puncticollis (Boh.) (Coleoptera:

Brentidae) infestation using varietal and cultural control at Kuru, Nigeria

C. N. Ehisianya and N. A. Onunka

Sweetpotato Research Programme, National Root Crops Research Institute,

Umudike, P. M. B. 7006, Umuahia, Abia State, Nigeria. Corresponding

author: [email protected]

Abstract

Varietal and cultural control tactics were investigated for the management of field infestation

of sweetpotato Ipomoea batatas (Lam.) by Cylas puncticollis (Boheman) in 2008. The experiment was conducted at the Research Farm in the National Root Crops Research

Institute (NRCRI), Kuru sub-station, (Latitude 09°44’N , Longitude 08°44’E and Altitude 1231.6m above sea level), Plateau State Nigeria. The (6x3x3) factorial combinations were

laid out in a Randomized Complete Block Design and replicated thrice. Results indicated that significantly higher root yield were obtained from sweetpotato varieties TIS2532.op.1.13,

followed by TIS87/0087 and the least was from TIS8164. The response of roots to attributes

of C. puncticollis as a pest followed similar trend with 52.74% infestation on TIS2532.op.1.13 and 39.45% on TIS8164. Sweetpotato roots harvested from mound and ridge methods of

tillage recorded significantly higher yields compared with the flat method, and had significantly higher attributes of C. puncticollis. The delay in the time of harvest from 4 to 6 months after

planting (MAP) significantly increased score (2.00 - 4.28), number of adults (1.54 – 9.11) and damage (15.57% – 66.74%) to sweetpotato roots. Carotene-rich, orange-fleshed

sweetpotato (var. CIP440293) had moderate yield and susceptibility to C. puncticollis at the

Guinea Savannah agro-ecology of Nigeria.

Keywords: Cylas puncticollis, infested roots, sweet potato, tillage method



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290

Pests and diseases status of local and improved cassava genotypes in selected

pilot sites in Cameroon

Maurice Tindo1,*, Emmanuel Njukwe 2 and Abdou Tenkouano3

1University of Douala, Faculty of Science, Department of Animal Sciences, B.P. 24157

Douala, Cameroon 2International Institute of Tropical Agriculture, Burundi Station, B.P. 8193

Bujumbura, Burundi 3AVRDC-The World Vegetable Center, Bamako, Mali

*Author for correspondence: Maurice Tindo, c/o International Institute of Tropical Agriculture,

Cameroon Station, BP 2008 Messa, Yaoundé, Cameroon; E-mail: [email protected].

Abstract

We conducted two main surveys in 2012 during the dry seasons in 29 sites within the five antennae of the “Programme National de Développement des Racines et Tubercules”

(PNDRT) Cameroon to assess potential changes triggered by the introduction of the improved genotypes on cassava pest and disease status. Standard methods were used to evaluate pest

incidences, population and damages, natural enemies’ occurrences, diseases incidences and damages severities on both local and improved varieties. Seven predominant pests were

found damaging cassava plants including; the cassava mealy bug (CMB), cassava green mite (CGM), red mite (RM), white fly (WF), spiralling white fly (SWF), the African root and

tuber scale (ARTS) and the variegated grasshopper (VG). The incidence, number of individuals

and damages severities of all pests varied considerably between survey dates, antennae and varieties. Natural enemies of CGM were observed but not in all the antennae. Symptoms of

six diseases were observed in cassava fields including cassava mosaic disease (CMD), cassava anthracnose disease (CAD); cassava bacterial blight (CBB), cassava root rot (CRR),

brown and white leaf spot. The incidence and severity of diseases also varied considerably between antennae, sites and cassava varieties. Their severities were generally mild to

moderate. In general, improved genotypes were significantly resistant to CMD, CBB and

CAD diseases than local material. It was observed that although the introduction of improved cassava genotypes has not significantly affected the cassava pest status, effect of CMD had

reduced considerably. However, both local and improved genotypes were attacked by other diseases like CAD and CBB. Concerted efforts should therefore be directed towards the

development, selection and introduction of resistant materials to the major pests and diseases.

Key words: Cassava mosaic disease, green mite, IMP, predatory mite



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291

Monitoring survey and status of the Cassava Anthracnose Disease (CAD) in

Luapula and Eastern Provinces of Zambia

Mathias Tembo and Patrick Chikoti

Zambia Agriculture Research Institute, Mount Makulu Research Station, Private Bag 7,

Chilanga, Lusaka, Zambia

[email protected] and [email protected]

Abstract

Cassava is an important food crop in urban and rural areas of Zambia and plays a principal role in the economy of the country. The low cassava productivity is partly due to cassava anthracnose disease (CAD). Though the disease has been reported in cassava fields, disease

status has not been evaluated. Because of the economic importance of CAD, a survey was

conducted in Luapula and the Eastern Provinces. The objective was to determine the incidence and severity of CAD in Zambia. The disease severity for CAD was scored on scale of 1-5.

Incidence was determined in a “Z” configuration. Fifteen plants per field were counted equidistant from each other within rows. There were significant differences (P>0.05) in the

CAD severity. In Luapula province the mean CAD severity was 1.7. Samfya recorded the highest CAD severity and Nchelenge the lowest severity (1.2). The highest incidence for

CAD was observed in Mansa district (75%) and lowest in Nchelenge district (21.5%). Similarly,

significant differences (P>0.05) were observed in CAD severity in the Eastern provinces. The mean CAD severity was 1.7. Lundazi recorded the highest severity (1.8) and Rufunsa

the lowest (1.5). The incidence for CAD was highest in Chipata district (60%) and least in Rufunsa district (53%). Sustainable management of CAD would significantly improve cassava

production in Zambia.

Keywords: Cassava, Cassava anthracnose disease, incidence, severity, Zambia.





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292

Genotypic Resistance of Yam (Dioscorea spp) to Post-harvest Microbial Rot

Nyadanu, D., Dapaah, H. and Agyekum, A.D.

Department of Crop and Soil Sciences Education, Laboratory of Applied Plant Genetics, College

of Agriculture Education, University of Education, Winneba. P. O. Box 40,

Asante Mampong, Ghana.

[email protected]

Abstracts

Post harvest microbial rot is an important disease that causes severe yield losses in yam (Dioscorea spp). Rot from microbial infection of healthy yam tubers reduce their table quality and render them unappealing to consumers. The purpose of this research was to

investigate genotypes, storage techniques and their interaction in resistance to internal rot in

yam. Four local varieties; Labalkor, Kplondzo, Olordor and Fushiebila were evaluated for post harvest microbial internal rot using four storage techniques; barn, pit, platform and heap

methods. There were significant (p< 0.001) differences among the genotypes for resistance to internal rot. Olordor and Kplondzo recorded the least of internal microbial rot, suggesting

their potential in resisting the disease. There were also significant differences (p< 0.005) among techniques of storage of yam in resistance to internal rot. Barn and platform methods

were most suitable to reduce the incidence of internal rot in yam. Interaction between the

yam genotypes and the storage techniques was not significant ( p> 0.005) suggesting that resistance to internal rot in yam was not storage technique specific.

Key words: Yam, Dioscorea spp., Internal rot, Storage techniques, Post harvest, Microbial



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293

Pests and diseases associated with yam bean (Pachyrhizus erosus) cultivation at

farmers’ levels in the central region of Benin

A. Bouraïma1, R. Sikirou214, P. Y. Adégbola3, A. Adjanonhoun4, B. Zocli2, L.

Gnancadja, M. Sézolin, K. Hell5, K. Ahiou6, Feu P. Fandohan7 et G. A. Mensah8. 1 Centre Communale pour la Promotion Agricole de Zogbodomey, 10 BP: 479

Cotonou, République du Bénin 2 Laboratoire de Défense des Cultures, Centre de Recherches Agricoles d’Agonkanmey, Institut

National des Recherches Agricoles du Bénin (INRAB) 01 BP 128 Porto-Novo 3 Programme d’Analyse de la Politique Agricole (PAPA), Institut National des Recherches

Agricoles du Bénin (INRAB), 01 BP 128 Porto-Novo 4 Centre de Recherches Agricoles Sud-Bénin de Niaouli, Institut National des Recherches

Agricoles du Bénin, 01 BP 884 Recette principale, Cotonou, Bénin 5 International Institute of Tropical Agriculture, 08 BP 0932, Cotonou, Benin.

6 Centre de Recherches Agricoles Centre-Bénin de Savè, Institut National des Recherches

Agricoles du Bénin, 01 BP 884 Recette principale, Cotonou, Bénin 7 Programme Technologie Agricole et Alimentaire, Centre de Recherches Agricoles


Porto-Novo, Bénin 8 Centre de Recherches Agricoles d’Agonkanmey, Institut National des Recherches Agricoles du


Abstract

To assess the pest pressure of yam bean (Pachyrhizus erosus) in agroecologies conditions of central Benin, experiments were conducted from July 2010 to January 2011 and from August 2011 to January 2012 in a completely randomized block design with 4 replications and

three treatments which were EC 533 and EC Kew cultivars of Pachyrhizus erosus and

cowpea variety Kpodji-Guèguè. Trials were planted at the experimental field of the Agricultural Research Centre (CRA-centre) of the centre of the National Institute of Agricultural Research

of Benin located in Savè. The major pests encountered in P. erosus were Ootheca mutabilis Medythia quaterna, Piezotrachelus varium, Megalurothrips sjostedti, Brevipalpus

phoenis. In cowpea, besides the above cited pests, the aphid Aphis craccivora was also seen. Pest pressure was higher in cowpea with severity of damage varying between 0.8% to

88.9% and low in P. erosus, with a severity of damage varying between 0.7% and 3% in the

leaves. The percentage of perforated green pods ranged from 57.2% to 64% in cowpea compared to 12.5% to 16% for P. erosus. Cercospora disease caused by Cercospora sp.

and the disease of leaf blight were the observed diseases. Cercospora disease. was observed not only on cowpea but also on P. erosus.

Key words: Pachyrhizus erosus, yam bean, pests, diseases, Benin


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294


Anisha Dayarama, Allen Oppongb, Anja Jäschkeac, James Hadfielda, Marianna

Baschierad, Renwick C.J. Dobsonaf, Samuel K. Offeig, Dionne N. Shepherdd,

Darren P. Martine, Arvind Varsaniaf h,” aSchool of Biological Sciences, University of Canterbury, Ilam, Christchurch 8140, New Zealand

bVirology Section, CSIR-Crop Research Institute, Kumasi, Ghana cDepartment of In fectious Diseases, University o f Heidelberg, D-69120 Heidelberg, Germany

dDepartment of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701

Cape Town, South Africa eComputational Biology Group, Institute of Infectious Diseases and Molecular Medicine,

University of Cape Town, Cape Town, South Africa fBiomolecular Interaction Centre, University of Canterbury, Ilam, Christchurch 8140,

New Zealand gSchool of Agriculture and Consumer Sciences, University of Ghana, Legon, Ghana

hElectron Microscope Unit, University of Cape Town, Rondebosch, 7701 Cape Town, South

Africa

Abstract

The application of sequence non-specific rolling circle amplification of circular single stranded (ss) DNA molecules to viral metagenomics has facilitated the discovery in various ecosystems

of what is probably a diverse array of novel ssDNA viruses. Here we describe a putative novel ssDNA virus (at a genome level), cassava associated circular DNA virus (CasCV),

isolated from cassava leaf samples infected with the fungi Collectotrichum and Plectosphaerella. CasCV has a circular ambisense genome and shares significant genome

similarities with Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV- 1), Mosquito VEM virus SDBVL and Meles meles faecal virus (MmFV). The CasCV genome

(2220 nt) has three large open reading frames. While it is probable that one of these encodes

a capsid protein, the other two probably express a replication associated protein (Rep) following the removal of an intron such as that found in the Rep encoding genes of some geminiviruses.

This Rep would contain four conserved rolling circle replication (RCR) related motifs that have previously been identified in geminivirus, circovirus and nanovirus Reps. Given both

that the CasCV Rep and CP share 62.7% and 39.8% amino acid identity respectively with the Rep and CP of SsHADV-1, and that CasCV was discovered associated with cassava

infecting fungi, we suggest that CasCV should be classified within the mycovirus taxonomic

family. However, host range studies using infectious clones will be required to demonstrate the novel virus’ likely origin and actual host species.


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295

Can we maintain cassava clean seed systems using certification guidelines that

incorporate virus testing? A comparison of standard and real-time PCR testing

techniques

*Rudolph R. Shirima, Frank Fovo, Juma W. Yabeja and James P. Legg

International Institute of Tropical Agriculture (IITA), P.O.BOX 34441, Dares salaam, Tanzania

*[email protected]

Abstract

Cassava production in sub-Saharan Africa is adversely hampered by several pests and diseases. CBSD is considered the most devastating to cassava production throughout East and some

parts of Central Africa. The ‘New Cassava Varieties and Clean Seed to Combat CBSD and CMD’ project (5CP) aims at delivering clean and virus tested pre-basic seed. 5CP is working

together with the Tanzania Official Seed Certification Institute (TOSCI) to develop seed certification guidelines for cassava in order to ensure sustainable clean seed production. To

achieve this, the level of virus infections in seed multiplication sites needs within stringent tolerance levels. Using reliable and cost effective diagnostic methods this can be achieved,

by using minimal reaction volumes and intelligent sample batching cut down on testing costs.

We performed dilution series tests to compare virus detection sensitivities of standard and real-time RT-PCR. RNA extraction from CBSVs-infected symptomatic or CBSVs-free

asymptomatic cassava leaves was done using a standardized CTAB method. Serial dilutions of sap or purified RNA were performed using sap or purified RNA from either symptomatic

or asymptomatic leaves. Presence/absence and identity of virus in the selected samples had been initially determined. Finally a serial dilution of the infected RNA extracts was performed

in water in order to compare the effect of impurities on the detection efficiency of the

diagnostic tools tested. Results revealed that real-time RT-PCR using TaqMan chemistry is at least a thousand fold more sensitive than standard RT-PCR. We therefore advocate the

use of real-time RT-PCR as the best currently available diagnostic method for virus testing programmes that support clean seed production and certification.




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296

Taro leaf blight disease: Solutions for West and Central Africa

Walter N. Leke 1,2*, Victorine Fornkwa3, Badara Gueye 2, Rachid Hanna3, Joseph

Onyeka4, Michael T. Abberton2 and Robert Asiedu2

1 Institute of Agricultural Research for Development (IRAD), Cameroon 2 International Institute of Tropical Agricultures (IITA), Ibadan, Nigeria

3 IITA-Cameroon, Yaoundé, Cameroon 4 National Root Crops Research Institute, Umudike, Nigeria

*Virology and Molecular Diagnostics, IITA, Ibadan, Nigeria. [email protected]

Abstract

Root and tuber crops (cassava, cocoyam, yam, potato, sweet potato and taro) play an essential role in the diet, health, and the overall wellbeing and sustainability of most African communities.

Amongst these root and tuber crops, Colocasia esculenta (taro) holds promise as it has been least affected by pests and diseases since its introduction into the African continent

from Southeast Asia and can be cultivated in waterlogged environments, thus ensuring a year round availability of food when the others are out supply. The cultivation of taro is

mostly by rural women for the sustainability of their families. Since 2009, the African continent has withnessed an outbreak of a devastating leaf blight disease of taro, the taro leaf blight

disease (TLBD), caused by the fungus Phytopthora colocasea. In Cameroon as well as

other parts of West and Central, the situation is alarming and there have been cases of a 100% incidence, resulting in the complete destruction of hectres of farms. Without urgent

action, the continent risks the extinction of nearly all local taro accessions. The Centre for Pacific Crops and Trees (CePaCT) in the Fiji Islands has developped resistant/torelant taro

varieties to TLBD and is distributing them widely in the form of tissue culture plantlets - through the Secretariate of the Pacific Cmmunities (SPC) - to national programs/centres

interested in taro research. Cameroon and Nigeria acquired some of these accessions for on farm evaluation and preliminary results in Cameroon shows that out of the ten accessions

received, nine are either resistant or tolerant to the disease but other agronomic characters

such as tuber yield, cooking quality, taste, etc, still need to be avaluated. The SPC accessions therefore offer a possible solution for the TLBD epidemic in West and Central Africa.

Key words: Colocasia esculentus, Phytopthora colocasea, host plant resistance, disease

tolerance.



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297

Occurrence of sporadic dry root rots caused by Phaeolus manihotis Heim

(Basidiomycete; Polyporaceae) on cassava in the Bas-Fleuve district of DR

Congo and attempts for its control

Kassongo W. Tata Hangy, K. Bambala, S. Nluta and Nzola M. Mahungu

Abstract

In 2009 severe dry root rots were observed in cassava farms in the secondary forest areas of Kimbianga and spread all around the Lukula territory of the Bas-Fleuve district. A strange

yellowish mushroom that was identified as Phaeolus manihotis Heim was associated with

the rots. P. manihotis is known as a latent species in most of the secondary forests of Africa. Preliminary investigations initiated by IITA’s cassava project in DRC indicated that all cultivated

varieties, including those resistant to the cassava mosaic disease (CMD) were affected, but at variable degrees. In the attempts to stop the spread of the disease, fungicide (benlate as

systemic fungicide) was used. The fungicide was sprayed in the soil at planting around the cutting and thereafter around the plant at monthly interval for 3 months. The 2 treatments

were compared to no fungicide application treatment. Results of the tests showed that the

fungicide applied at planting only didn’t really stop the development of P. manihotis on the crop; but when applied monthly for 3 months, the fungicide reduced the incidence of the root

rots by 80%. The overall average of the rots was 29.4% when the fungicide was applied at planting and only 0.4% when the fungicide was applied monthly for 3 months. In addition,

factors that were supposed to be responsible as source of contamination and mode of propagation of the disease were assessed in another trial. The source of contamination was

measured using cuttings from plants that showed root rots in the previous cropping season

and those which did not show any root rots, thus healthy plants. Also, 2 types of plots were considered: (a) a plot where cassava was planted just after cassava as previous crop; and

(b) a 2-year fallow plot. Three best varieties resistant to CMD were used to evaluate the treatments. They were; Lueki reported to be susceptible to the rot disease, Disanka, observed

to be tolerant and Nsansi one of the preferred varieties. The analysis of the data collected showed no statistical differences in the root rots incidence between the treatments measured.

At the end of the experimental period, P. manihotis became less frequent than the previous

seasons.


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298

Characterizing the effects of degenerative diseases of cassava and yam

P. Lava Kumar1, D. Coyne 2 and J. P. Legg3

1International Institute of Tropical Agriculture (IITA), Oyo Road, PMB 5320, Ibadan, Nigeria 2IITA, P.O. Box, 30772-00100, Nairobi, Kenya

3IITA, Plot 25, Mikocheni, PO Box 34441, Dar es Salaam, Tanzania

*[email protected]

Abstract

Degenerative diseases caused by infectious agents propagated through planting material reduce plant vigour, longevity, quality and quantity. Cassava (Manihot esculenta) and yam (Dioscorea spp.) are major food staples propagated clonally using stems and tubers

respectively. Both crops are severely affected by degenerative diseases in sub-Saharan

Africa (SSA). For cassava, the virus diseases–cassava mosaic and cassava brown streak– are considered to be the major causes of planting material degeneration. For yam, yam

mosaic virus and the phytoparasitic , tuber-associated nematodes Scutellonema bradys and Meloidogyne spp. are the main sources of degeneration. Studies during the past decade

have established high incidence (>60%) of these agents in the major cassava and yam production regions in SSA. Recently, the CGIAR Research Program (CRP) on Roots, Tubers

and Banana (RTB) has commissioned a project to determine the factors responsible for

degeneration of banana, cassava, potato, sweetpotato and yam, with a view to developing sustainable solutions to control degenerative diseases. Under this project framework,

experiments have been initiated to verify the impact of viruses and nematodes on seed degeneration and production and to characterize the interactions between environment,

cultivar, pest/pathogen and cropping practices. The ultimate aim is to develop degeneration management strategies that will improve the quality of seed material produced, particularly

within the informal seed system sector.



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299

BIOTECH.


Anisha Dayarama, Allen Oppongb, Anja Jäschkeac, James Hadfielda, Marianna

Baschierad, Renwick C.J. Dobsonaf, Samuel K. Offeig, Dionne N. Shepherdd,

Darren P. Martine, Arvind Varsaniafh,”

aSchool of Biological Sciences, University of Canterbury, Ilam, Christchurch 8140, New Zealand

bVirology Section, CSIR-Crop Research Institute, Kumasi, Ghana cDepartment of In fectious Diseases, University o f Heidelberg, D-69120 Heidelberg, Germany

dDepartment of Molecular and Cell Biology, University of Cape Town, Rondebosch, 7701

Cape Town, South Africa eComputational Biology Group, Institute of Infectious Diseases and Molecular Medicine,

University of Cape Town, Cape Town, South Africa fBiomolecular Interaction Centre, University of Canterbury, Ilam, Christchurch 8140,

New Zealand gSchool of Agriculture and Consumer Sciences, University of Ghana, Legon, Ghana

hElectron Microscope Unit, University of Cape Town, Rondebosch, 7701 Cape Town,

South Africa

Abstract

The application of sequence non-specific rolling circle amplification of circular single stranded (ss) DNA molecules to viral metagenomics has facilitated the discovery in various ecosystems of what is probably a diverse array of novel ssDNA viruses. Here we describe a putative

novel ssDNA virus (at a genome level), cassava associated circular DNA virus (CasCV),

isolated from cassava leaf samples infected with the fungi Collectotrichum and Plectosphaerella. CasCV has a circular ambisense genome and shares significant genome

similarities with Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV- 1), Mosquito VEM virus SDBVL and Meles meles faecal virus (MmFV). The CasCV genome

(2220 nt) has three large open reading frames. While it is probable that one of these encodes a capsid protein, the other two probably express a replication associated protein (Rep) following

the removal of an intron such as that found in the Rep encoding genes of some geminiviruses.

This Rep would contain four conserved rolling circle replication (RCR) related motifs that have previously been identified in geminivirus, circovirus and nanovirus Reps. Given both

that the CasCV Rep and CP share 62.7% and 39.8% amino acid identity respectively with the Rep and CP of SsHADV-1, and that CasCV was discovered associated with cassava


(ISTRC-AB)

300

infecting fungi, we suggest that CasCV should be classified within the mycovirus taxonomic family. However, host range studies using infectious clones will be required to demonstrate

the novel virus’ likely origin and actual host species.


(ISTRC-AB)

301

Application of biotechnology to yam improvement in CSIR-Crops Research

Institute (CRI)

Quain, M,D., R.N. Prempeh, A. Agyeman, J.Y. Asibuo, E.Y. Parkes, P.F. Ribeiro,

E. Otoo and M. Egnin

Abstract

Yam, Dioscorea spp, belongs to the family Dioscoreaceae. It is an important crop in Ghana

with 6.32% of arable land under yam cultivation. Yam significantly contributes about 16% to Agricultural Gross Domestic Product. Agriculture research has generally contributed to the

improvement of the crop. From 1996 to date, the Biotechnology Section in CSIR-CRI has made several efforts toward the improvement of the crop using tissue culture and molecular

biology to compliment conventional research efforts. Prominent among these attempts is the development of a reliable cryopreservation system for the conservation of germplasm at

ultra low temperatures. A successful system for the genetic manipulation of yam has also been developed in collaboration with Tuskegee University Alabama, USA. A more efficient

in vitro rapid multiplication system for local accessions has been developed, genotyping used

to rogue out duplicates in conserved germplasm and molecular characterisation of local accessions carried out. This paper highlights the various biotechnological applications that

can form the basis for further research efforts for yam improvement and production in Ghana and the Sub-Saharan African.


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302

Screening of cassava genotypes for resistance to cassava mosaic disease using

morphological and molecular markers

P. A. Asare 1, I. K. A. Galyuon2, E. Asare-Bediako1 *, J. K. Sarfo3 and J. P. Tetteh1

1Department of Crop Science, University o f Cape Coast, Cape Coast, Ghana. 2Department of Molecular Biology and Biotechnology, University of Cape Coast,

Cape Coast, Ghana.

*[email protected] .uk

Abstract

Cassava mosaic disease (CMD) is the most-important disease of cassava (Manihot esculenta) in Ghana, and is a potential threat to cassava production in the country. The study was conducted to identify cassava genotypes resistance to CMD and to identify strains of

cassava mosaic geminivirus (CMG) infecting cassava in Ghana. Both morphological and

molecular markers were used to screen 38 cassava genotypes against CMD infection. Morphological studies revealed one genotype Capevars as highly resistant whilst three others

Adehye, Nkabom and KW 085 were moderately resistant, showing mild symptoms. PCR analyses using strain specific primers however, detected the virus in all the three moderately

field resistant cultivars but absent in Capevars. Neither East African cassava mosaic virus (EACMV) nor the East African cassava mosaic virus-Uganda variant (EACMV-Ug)

but four variants of African cassava mosaic virus (ACMV) were detected; and apart from

Capevars all the other 37 genotypes were susceptible to one or more of the viruses. By screening the four resistant genotypes with SSR markers associated with the dominant

resistance gene CMD2, all the four genotypes showed the presence of the gene. The study confirmed ACMV as the main CMG infecting cassava in Ghana and a high CMD-resistant

cassava cultivar, Capevars identified.



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303

Phenotypic evaluation of a multi-location cassava breeding trial to improve a

genomic selection training population

U.K. Uchendu1, 2, E. Parkes1, O.O. Aina1, M.O. Akoroda2, P. Kulakow1

1International Institute of Tropical Agriculture (IITA), P.M.B 5320, Ibadan Nigeria. 2Department of Agronomy, University of Ibadan, Ibadan, Nigeria.

*Corresponding author. Email: [email protected].

Abstract

Thirty white fleshed cassava genotypes derived from crosses between genotypes from West Africa x East Africa and West Africa x Latin America were evaluated in five major

agroecological zones in Nigeria during 2012-2013. The objectives of the study were (i) to

evaluate genotype (G), environment (E), and G X E interaction on cassava mosaic disease (CMD), cassava bacterial blight (CBB), cassava anthracnose disease (CAD), and cassava

green mite (CGM) in a multi-location uniform yield trial and (ii) to characterize morphological variation to improve a genomic selection training population that includes these genotypes.

The trials were established in a randomized complete block design with four replications.Combined analysis of variance showed differences (P-<- 0.001) among E for

all traits evaluated. Genotypes did not differ significantly in their field reaction to CMD and

CBB but showed variation in mild CAD symptoms and more severe, CGM reaction. Environmental variation accounted for 53.09% of the total sum of squares for CMD; 49.53%

for CBB; 64.76% for CAD and 59.39% for CGM. The high influence of E demonstrated large differences in disease and pest severity in different locations. Morphological parameters

such as levels of branching, angle of branching, height of branching, and plant height varied significantly among genotypes. Genotypes I090488, I090536 and I090590 branched the most,

while I090574, I090564 and TMEB 419 (check) branched the least. Our results revealed

that genotypes I090506, I090537 and I090609 were either low branching or have a wide angle of branching. This is significant as it helps in suppressing the weed flora, especially

spear grass (Imperata cylindrical) by forming a dense canopy.

Keywords: cassava breeding, phenotype, genomic selection, training population, genotype x environment interaction.



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304

Technical efficiency analysis of cassava production in Nigeria; implication for

increased productivity and competitiveness

Osun Taiwo1, Ogundijo Stephen Dayo2 and Bolariwa K.O.3

1. Institute of Food Economics and Consumption Studies,

University of Kiel, Olshausenstraße 40, 24098 Kiel, Germany 2. International Institute of Tropical Agriculture, PMB 5230, Oyo road Ibadan, Nigeria

c/o IITA Ltd, Carolyn House, 26 Dingwall Road, Surrey CR9 3EE, United Kingdom 3Regal College P. O. Box 85, Sagamu, Ogun State Nigeria

Osun Taiwo. Email; [email protected]

Abstract

This paper uses stochastic frontier model to examine resource use efficiency of cassava farmers in South-west Nigeria using farming level data. We employ transcendental logarithm (TL) production function which is theoretically superior to the restrictive Cobb-Douglas

production function widely employed to examine resource use efficiency of the Nigerian

smallholder farmers in previous studies. Empirical results show that education, planting of the improved varieties and access to extension education significantly and positively affect

production efficiency. Cassava stem (seeds), chemical fertilizer and farm size are of increasing function while labour and herbicides are of decreasing function. The interaction functions of

the TL model shows that stem/fertilizer and stem/land are good compliments suggesting that the improved cassava varieties (stem) are highly fertilizer responsive therefore, access and

intensive use of fertilizer will increase improve cassava productivity. In the same vein, adoption

of correct spacing will increase cassava productivity. In contrast, fertilizer/herbicides and labour/herbicides have substitutional tendencies meaning that, increasing the use of one could

lead to reduction in use of the other. Production function exhibits increasing return to scale and technical efficiency scores range from 97.5 to 21.90 percent with the average score of

79.23. This shows that resources are underutilized and there is room for improvement as efficiency can still be improved by about 20 percent. Policy measures that ensure better

access to production inputs and extension education in order to raise productivity per unit

land and lower per unit costs of production are recommended for efficient and competitive cassava production

Key Words: Technical efficiency; Stochastic frontier; Translog production function;

Competitive cassava farming; Nigeria



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305

Phenotipic evaluation of cassava mapping population for drought resistance traits

in the Guinea Savannah ecology of Ghana.

K. Acheremu1, J. Adjebeng-Danquah1, E. Parkes2, A. Agyemang2, B. Pepra2, E.

Okogbenin3, O. Akinbo3, C. Egesi3, F. Ewa3

1CSIR-Savanna Agricultural Research Institute, Tamale. 2CSIR-Crops Research Institute, Kumasi.

3National Root Crops Research Institute Umudike, KM 8 Ekot Ekpene Road,

PMB 7006, Umuahia, Abia State, Nigeria. [email protected]

Abstract

The ability to produce improved performance under difficult or marginal conditions is related

to various physiological traits. This study was conducted to map a population of 157 pseudo- F2 drought tolerant lines of cassava progenies obtained from crosses made from 2 non-

inbred parents in Umudike, Nigeria, for traits conferring drought resistance to cassava. The trial was carried out in the 2012 season at Savanna Agricultural Research Institute’s research

field in an augmented design with 7 block, together with the 2 parents (98/0505-female and

97/0510-male) and 5 local cassava materials randomly arranged in each block to serve as checks. Data were collected at monthly interval after 2 months of plant establishment, until

the trial was finally harvested at 12 MAP. Preliminary results indicated significant differences (using a mixed model fitted in REML) in root tuber yields, biomass, number of roots/plant,

leaf retention and dry matter yield. The mean root yield of the progenies recorded was 18.1t/ ha, with the maximum yield of 45.0 t/ha. The heritability estimated for root tuber yield was

0.71. Ten (10) cassava progenies recorded the highest root yields ranging from 36.25 to

41.98 t/ha, which are above the highest root yield recorded by the parents (female), as well as the 5 local checks. Large number of the progenies (66) of the cassava lines recorded

yields above the mean root yield. Five (5) lines recorded the highest number of root/plant, above the best performing parent, and 56 lines recorded between 6 and 14 roots/plant, which

are above the mean root number. Only 6 lines recorded higher number of roots/plant than the Parent “98/0505” and above all the local checks. The mean dry matter (DM) recorded was

28.8 %, with the majority of the progenies recording DM ranging from 28.80 to 39.75% above the mean. Only 7 lines recorded a DM ranging from 36 to 39.8%, a range that was

higher than that of Pontisange, one of the best performing local checks in terms of DM

percentage, as well as the rest of the local checks, and the 2 parents. The heritability estimate among the genotypes in the traits measured were positive (0.5), indicating that simultaneous

progress for the traits is feasible.

Key words: Drought, phenotypic evaluation, augmented design, root yield, heritability estimate



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306

A survey of yam diversity, production and utilization in southern Ghana

Aboagye, L.M., M. O. Opoku-Agyeman and S. K. Owusu

Council for Scientific and Industrial Research, Plant Genetic Resources Research Institute,

P. O. Box 7, Bunso (ER), Ghana.


Abstract

A survey was conducted in four yam growing communities in southern Ghana, with the objectives of analyzing the diversity of yam species being cultivated, extent of production, yams preferred and challenges confronting yam production. A total of 264 farmers were

involved in the survey, 200 men and 64 women. Six yam species were encountered and 136

accessions were characterized. Invariably in the four communities most of the accessions were cultivated in small areas by few households. Preference of yams cultivated depended

mostly on maturity, ability to withstand biotic and abiotic stresses and multiple utilization as food sources. Eleven constraints were enumerated which needs to be addressed to ensure

sustainable yam production.



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307

Determinants of Technical Efficiency among Seedyam Entrepreneurs in

Anambra State.

Onwuka1 S., Mbanasor2 J. A., Ekwe 1 K. C. National Root Crops Research Institute, Umudike

Michael Okpara University of Agriculture, Umudike. Dept. Agric. Economics

[email protected]

Abstract

This study examined the Technical efficiency of Seedyam Entrepreneurs in Anambra State using minisett technology. A multi-stage random sampling technique was adopted in choosing the sample. Primary data generated from the survey were analyzed using descriptive statistics

and econometric tools. The result showed that men constituted a greater percentage (80%)

of those involved in seedyam enterprise, while mean age of the respondents was 54 years. respondents were also shown to be educated at various levels. 50% of the respondents had

farming experience below 20years. Moreso, the analysis showed an average household size of 4 people. The Cobb–Douglas Stochastic function was adjudged the best fit for technical

efficiency based on the high values of the Log-likelihood function, number of significant variables and appropriateness of a-priori expectations. It showed that the coefficients of

labour, fertilizer use, planting materials, and depreciation on farm tools were all positive.

Socio-economic determinants which affected technical efficiency were age of respondents, extension visit and membership to cooperative and were significant at 5%. Fertilizer use and

access to credit were indirectly related to technical efficiency and were significant at 5% and 10% respectively. It was recommended that youths should be encouraged to go into

seedyam enterprise since it holds great prospect for income generation and export; this will definitely reduce unemployment in the nation. Policies that effectively enhance technical

efficiency of farmers should be put in place by the government. This will reduce poverty and

enhance food security, which is cardinal in the millennium developmental goal.

Keywords: Determinants, Technical Efficiency, Seed yams, Entrepreneurs



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308

Impact of Taro Leaf Blight on Supply Response of Cocoyam in Nigeria:

Implications for Cocoyam Trade

Okoye, B.C., Chukwu, G.O., Onyeka, J., Onwubiko, O and Okpechi, I

National Root Crops Research Institute, Umudike, P.M.B 7006 Umuahia,

Abia State, Nigeria.

[email protected]; [email protected]

Abstract

Cocoyam is an important staple food through out the world and Nigeria. The demand for cocoyam exceeds the domestic supply and there appears to be a deceleration in the growth

potential of cocoyam from 2009 probably because of the devastating effect of Taro Leaf Blight in Nigeria. Taro leaf blight (TLB) caused by Phythophtora colocasie is a new disease

of Colocasia spp observed in Nigeria in 2009. The study attempts to examine the impact of TLB on production, area and productivity of cocoyam from 2000 to 2011 in two periods

(before the blight- 2000 to 2008 and after the blight 2009 to 2011). Results reveal that output, area and productivity of cocoyam exhibited positive trends before the impact (2000 – 2008);

Area planted with cocoyam exhibited negative trend after the blight while output and

productivity stagnated within the same period. The results of the chow’s test analyses show that the F-value was significant at 5% level of probability within the two periods for production,

area and productivity of cocoyam implying a significant difference in production, area and productivity of cocoyam before and after the blight. Reduction in production, area and

productivity of cocoyam was therefore was principally due to the impact and devastation caused by TLB. The results therefore call for the need to breed for resistance and use of

chemicals to mitigate this impact. The International Network for Edible Aroids (INEA) is a timely intervention to farmers in Nigeria and West Africa suffering from the consequences

of this impact.

Key words: Taro Leaf Blight, Cocoyam and Nigeria





(ISTRC-AB)

309

Determinants of root crops cultivation: Potential safety crops in the face of

increasing aridity in southern Africa.

S. Siziba, A. A. Adekunle and K. Nyikahadzoi

Abstract

Climate change is increasingly becoming a reality with much of the southern African region projected to get more arid. This poses a great threat to smallholder farmers most of whom currently rely on rain fed agriculture for producing food crops. Farmers in this region may

have to adapt their cropping systems towards more drought tolerant crops. Root tubers,

which are more droughttolerant, present a good adaptation option. However, despite repeated crop failures experienced with maize the crop continues to dominate farmers’ cropping system.

The prime motivation of this study is to understand recent trends and determinants of root tuber production in the southern Africa region. An understanding of this will help in developing

and adapting policies for increasing resilience to climate change among the vulnerable smallholder farmers. The study analyses data at two levels: macro level and farm level.At

macro level, a trend analysis is applied totrace changes in root tuber production in Zimbabwe,

Malawi and Mozambique. This approach estimates an autoregressive model of root tuber production using a 20 year time series data. At farm level, a multinomial logit regression is

used to model farmers’ decisionchoices to cultivate root tubers.


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310

Identification of molecular markers associated with early bulking in cassava

(Manihot esculenta Crantz)

Olasanmi B.1,2,3, M.O. Akoroda1, E. Okogbenin3, C. Egesi,3 S.S. Kahya3, O.

Onyegbule 3, F. Ewa3, J. Guitierrez2, H. Ceballos2, J. Tohme 2 and M. Fregene 2,4

1Department of Agronomy, University of Ibadan, Nigeria; 2International Centre for Tropical

Agriculture (CIAT), Cali, Colombia; 3National Root Crops Research Institute (NRCRI),

Umudike, Nigeria, 4Donald Danforth Plant Science Center, St Louis, MO 63132

[email protected]

Abstract

Late root bulking is a major factor leading to rejection and abandoning of improved cassava genotypes in sub-Saharan Africa. Early Bulking (EB) varieties shorten the growth period

from planting to harvesting, better fit into environments with short rainy season and reduce

exposure to biotic and abiotic stresses thereby increasing productivity. This study was carried out to identify molecular markers associated with EB in cassava and enhance breeding for

the trait. Nine cassava hybrid populations were developed using six elite varieties as the parents. The progenies were evaluated for EB seven months after planting (MAP) at seedling,

clonal, and preliminary stages of breeding evaluation. The parameters measured were fresh root yield, harvest index, fresh shoot weight and number of storage roots per plant. The

progenies were assayed using 542 simple sequence repeat (SSR) markers. Bulked segregant analysis (BSA) was used to identify the SSR markers associated with EB in the populations.

Nine SSR markers (SSRY 106, (ESTs)SSRY 292, SSRY 239, (ESTs)SSRY 7, NS 194,

(ESTs)SSRY 47, SSRY 63, SSRY 250, and NS 323) were found to be closely linked (r = 0.3- 0.5; p < 0.05) to EB in six of the nine hybrid populations. Seven of the markers with 10% or

more coefficient of determination (R2) were linked to major quantitative trait loci (QTLs) associated with EB in cassava. The molecular markers identified in this study can be used to

select for early bulking in cassava and for further target-trait-improvement by pyramiding.

Key words: Late bulking – fresh root yield – Simple sequence repeat markers – quantitative

trait loci - hybrid populations



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311

Cassavabase (cassavabase.org): an integrated field breeding and genomics

database enables accelerated genetic gain in cassava

Afolabi Agbona1, Ismail Rabbi1, Lukas Mueller2 and Peter Kulakow1

1International Institute of Tropical Agriculture, Ibadan Nigeria; 2Boyce Thompson Institute,

Ithaca, New York USA

Abstract

Cassava, a major staple crop is receiving increase research for development attention to support its contribution as the main source of calories for 500 million people across the globe.

There is a need to unlock the full potential of cassava by applying genomics-assisted breeding

methodologies that use high-density genome marker data and novel statistical modelling to accelerate the development of improved varieties for farmers. To be effective, this approach

requires a centralized and easily accessible database that not only serves the purpose of depositing and retrieving data but also incorporates analysis pipelines. For this reason, a new

open access database (cassavabase.org) has been initiated cooperatively by Boyce Thompson Institute, Cornell University, the International Institute of Tropical Agriculture (IITA), National

Root Crop Research Institute (NRCRI) of Nigeria and NaCCRI (National Crop Resources

Research institute) of Uganda as part of the Next Generation Cassava Breeding project. Implemented as a Chado Database Schema, cassavabase is designed to support breeders

with comprehensive management of phenotypic data, genotypic information, and tools for performing Genomic Selection. Other dedicated genomics resources including genetic maps,

genome browser, BLAST are also implemented. Though still in the preliminary phase, it is already being used to assist genomic selection in three breeding programs. The database

welcomes contributions of data for use by all cassava scientists, thereby providing cassava

researchers and breeders a readily available key reference data source.


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312

Diversity analysis of sweetpotato (Ipomoea batatas [L.] Lam) germplasm from

Burkina Faso using morphological and SSR markers

Somé Koussao1, Vern Gracen2,3, Isaac Asante 2, Eric Danquah2, Jerôme Belem

and Jeremy Ouedraogo1

1 Institut de l’Environment et de Recherches Agricoles (INERA), 01 BP476

Ouagadougou, Burkina Faso 2 West Africa Centre for Crop Improvement ( WACCI), University of Ghana, PMB 30, Legon,

Accra, Ghana 3 Cornell University, USA

[email protected]

Abstract

Collection and characterization of plant materials have been used as preliminary studies for crop improvement. Diversity also has long been seen as vital for rational management and

use of crops. Thirty morphological characters and thirty SSR markers were used to assess the diversity among 112 sweetpotato (Ipomoea batatas [L.] Lam) cultivars in Burkina Faso

and to develop a core collection. Eight morphological characters were able to differentiate among the 112 accessions and to identify 11 duplicates while twenty eight SSR markers

were more informative in discriminating the accessions and to identify 5 duplicates. The diversity assessment using the two approaches revealed high diversity with a coefficient of

0.73 using the phenotypic data while moderate diversity with a coefficient of 0.49 was obtained

using the SSR markers. These results showed no correlations between the two approaches (with dissimilarity index of 0.95). Core collection was constituted using the SSR based data

while the eight discriminative phenotypic descriptors will be used in the identification of cultivars.

Keywords: Accessions genetic diversity, germplasm, markers, morphological characters,

simple sequence repeat, sweetpotato.



(ISTRC-AB)

313

In vitro low cost propagation of sweet potato plantlets: The cassava starch

option.

Alfred O. Ubalua, Ihezie, I. C., Ikpeama, A. I., Mbanaso, E.N.A. and C. N. Egesi.

Tissue Culture Unit, Biotechnology Research and Development Center, National

Root Crops Research Institute (NRCRI) Umudike, PMB 7006 Umuahia, Abia State.

[email protected]

Abstract

In vitro sweet potato plantlets were screened for their growth response and development on MS medium gelled with conventional gelling agents (agar and gelrite) and on five cassava

starches (NR 8082, TMS 92/0057, TME 419, TMS 98/0505 and TMS 30572). Appreciable successes were recorded in the rooting of the nodal cuttings in all the media. Our results

further informed that cassava starch-gelled media compared favourably to agar and gelrite gelled media. TME 419 and TMS 30572 starch gelled media performed poorly compared to

the controls (agar and gelrite) in 2009. The best shoot regeneration from the nodal explants

on agar, gelrite and cassava starch (TMS 30572) gelled media are 6.51, 6.01 and 7.06 cm respectively in 2011. Surprisingly, after 3 years storage, TMS 30572 and TMS 98/0505 starch-

gelled media improved significantly in all the growth parameters considered. Comparatively, gel strength of 0.2% gelrite, 0.7% agar and 9.6% cassava starch gave adequate support and

orientation of the plantlets. The impressive performance of the cassava starch–gelled media is of significance considering the prohibitive cost of agar and gelrite in the sub-Saharan

Africa.



(ISTRC-AB)

314

Genetic studies and breeding using next-generation sequencing markers in

cassava

Ismail Y Rabbi1*, Delphine Ly2, Peter Kulakow1, Melaku Gedil1, Martha

Hamblin2, Jean-Luc Jannink2,4

1 International Institute of Tropical Agriculture, PMB 5320, Oyo Road, Ibadan, Nigeria; 2 Institut National de la Recherche Agronomique.

3Department of Plant Breeding and Genetics, Cornell University, Ithaca, NY 14853, USA 4USDA ARS Tower Road, Ithaca, NY 14853, [email protected]

Abstract

Cassava (Manihot esculenta L.) has been considered an orphan crop characterized by an understudied genome and a limited number of genetic markers. However, the prolific advances

in next-generation sequencing technologies opens up unprecedented opportunities for genetic improvement of this crop that is important to food security of millions of households in the

tropics. We used Genotyping-by-Sequencing (GBS) to discover and genotype thousands of SNPs in F1 mapping populations and a collection of improved varieties of cassava held by

the International Institute of Tropical Agriculture (IITA). The generated GBS markers were used to carry out high-resolution interval mapping and genome-wide association study in the

F1 and the breeding populations, respectively. Quantitative trait loci (QTLs) underlying several

traits including resistance to the devastating cassava mosaic disease, increased provitamin-A content and several morphological traits were identified. Markers with strongest signals in

the QTL analyses were found close to either known candidate genes or previously published QTLs for several target traits. Moreover, we have developed a dense linkage map with more

than 6000 SNPs located in more than 1000 unique scaffolds, thereby contributing towards anchoring of the cassava genome sequence that is currently made up of nearly 13000 scaffolds.

Cassava breeding is usually a lengthy process that sometimes takes up to six years from first

crossing, followed by extensive field testing to selection of parents for the next breeding cycle. Using genome-wide marker data and historical phenotypic data, we also implemented

genomic selection-based breeding strategy, which involves statistical modeling to predict plant performance before field testing. The successful implementation of next-generation

sequencing-based genotyping in cassava shows that this approach is perfectly suited to studying the genetic architecture of key agronomic traits in this highly heterozygous and clonally

propagated species and will lead to more efficient breeding using genomic-assisted selection

strategy.



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315

, .

PROTECTION

Quantifying millipede (Diplopoda) damage on cassava (Manihot esculenta crantz)

and cocoyam (Xanthosoma sagittifolium (l.) schott) in the Western Region of

Ghana

K.O. Fening1,2*, i. Adama1, M. B. Mochiah1, M. K. Billah3 H. Braimah1, M

Owusu-Akyaw1 and J. A. Manu-Aduening1. 1CSIR-Crops Research Institute, P. O. Box 3785, Kumasi, Ghana

2Soil and Irrigation Research Centre, Kpong, Institute of Agricultural Research, College of

Agriculture and Consumer Sciences, University of Ghana, P. O. Box LG. 68, Accra, Ghana 3Department of Animal Biology and Conservation Science, University of Ghana, P. O. Box LG. 67,

Accra, Ghana

* [email protected]

Abstract

Millipedes as scavengers play an important role in ecological balance. Occasionally, when

conditions are favourable they develop high populations and invade farms. This study was to assess the pest status of millipedes on cassava and cocoyam by quantifying their damage in

three farming communities – Krakye Akuraa, Nsuopun and Tebe in the Western region of Ghana. Three farms each of mature cassava and cocoyam were randomly selected from

each location for harvesting and assessment of arthropod damage from February to March

2012. Damage in sprouting cassava stem cuttings was recorded from three newly established cassava fields from each location. Greatest damage by millipedes occurred on cassava roots

harvested from Krakye Akuraa and Tebe than Nsuopun. Damage on sproutingcassava stem cuttings ranged from 6-88% and was highest at Krakye Akuraa. Greatest damage occurred

on cocoyam at Tebe with greater damage in corms than cormels. Damage in roots and cormels ranged from 2-14% and 6-14%, respectively. Thus, there is need to develop cost-

effective management strategies to protect the sprouting cassava cuttings as the most

vulnerable stage of cassava.

Key Words: Millipede, damage holes, cassava, roots, cuttings, cocoyam, cormels, corm



(ISTRC-AB)

316

Intercropping cassava with plantain impacts pest population dynamics and

damage and plant growth and development.

Haruna Braimah, Issa, U.S., Kingsley Osei, Manu-Aduening, J. Ankomah, A.A.,

and Mochiah, M.B.

CSIR-Crops Research Institute, P.O. Box 3785, Kumasi, Ghana, West Africa.

Abstract

A study was initiated at two locations in the forest belt of Ghana to investigate the impacts of intercropping these crops on their growth, development and population dynamics and damage

of pest organisms within the association. Cassava and plantain were planted simultaneously with the cassava planted at 1X1M and the plantain at 3X3 in 12X12M plots. The experiment

was laid out in a randomised complete block design with five replications. Cassava in plantain suppressed the early growth and development of the plantain, with intercropped plantain at

least 5-6 weeks later in fruit maturation and produced fewer suckers, hands and fingers. On the other hand, plantain in cassava encouraged growth in height of cassava but had a

suppressing effect on branching. Populations of mites (green and red), and whiteflies did not

differ whether for sole or intercropped cassava but significantly more mealybugs were recorded on sole cassava than on the intercrop. Only few Zonocerus grasshoppers were recorded at

both locations on either planting culture. More millipedes were recorded on sole cassava in both locations but were more prevalent at Assin Fosu than Kwadaso. Similarly, more rotten

tubers were recorded for the sole than for intercropped cassava in Assin Fosu. It is concluded that plantain has a suppressing effect on millipede population build up and damage to cassava

roots. More banana weevils were trapped under sole plantain than under mixed plantain with

reduced toppling of plantains in the intercrop than in the sole crop, probably as a result of wind breaking effect of the intercropped cassava. Differences of weevil populations were

not significant and could not be credited with the toppling of plantains. Cassava appeared to adversely affect the early development and some yield parameters of plantain but reduced

toppling while plantain impacted millipede populations negatively reducing root rot of cassava thus positively impacting yield and probably root quality. No difference yields were noticed

between sole crops and intercrop. More research is required to understand this system and

make good use of the inherent benefits.

Key words: Plantain, cassava, intercropping, pests, biodiversity


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317

R OOT AND TUBER

CGIAR Research Program on Roots, Tubers, and Bananas (RTB): engaging

partners and enhancing impact

Graham Thiele ,

Director CRP-RTB Apartado 1558, Lima 12 Peru

[email protected]

Abstract

The RTB recognizes that research must embrace a broad portfolio of commodities beyond

the grain crops that have traditionally been the focus of food security initiatives. Roots, tubers, and cooking bananas and plantains are a critical component of the global food system.

As vegetatively propagated crops they have many similarities for genetic conservation,

breeding strategies, seed systems and post-harvest technology. The program is led by the International Potato Center, Bioversity International, the International Center for Tropical

Agriculture, and the International Institute for Tropical Agriculture and includes a wide spectrum of research-for-development stakeholders. This new collaboration, with its combined

scale and capacity, will increase the ability to advance research, share knowledge, and enhance impact. The program strategy is to exploit the underutilized potential of root, tuber, and banana

crops to reduce the risk of food shortages and malnutrition through increased yields and

stronger, more diversified crop systems. In addition, the CRP aims to increase income generation and foster greater gender equity. The CRP has identified impact pathways to

increase the likelihood that research is translated into improved livelihoods – especially among some of the world’s most poor and vulnerable populations. As it gets underway, it is quantifying

potential impacts as part of a priority assessment exercise. This sets the scene for reorganizing the programme around a smaller number of flagship products which can achieve higher

impact in terms of improved food security and reducing poverty. Engaging partners and stakeholders will be critical to successful implementation.

Keywords: planning, cassava, plantains, potatoes, sweetpotato, yams



(ISTRC-AB)

318

Characterization of Begomovirus strains found on Sweetpotatoes (Ipomoea

batatas (L) in Ghana

Linda A. Abrokwah1,4 , Charles Kwoseh2, Ted Carley3, Marian Quain4, Elizabeth

Parkes4,5, Allen Oppong4

1Student at Crop Science Department, KNUST 2. Kwame Nkrumah University of Science and

Technology(KNUST) 3.Centro Internacional de la Papa (CIP) -Ghana, CSIR-Crops Research

Institute, Kumasi 4. CSIR-Crops Research Institute, Kumasi Ghana, 5. International Institute for Tropical

Agriculture (IITA), Ibadan, Nigeria

Abstract

This is a proposal to characterize the incidence of sweet potato Begomoviruses found in 3 important growing ecologies in the Central, Volta and the Upper East regions of Ghana. The

study will also include characterization of secondary host plants to identify other sweet potato viruses to help guide farmers in the management of the disease. Molecular tools to be employed

will be the use of Polymerase Chain Reaction (PCR) detection assay for Begomoviruses

infecting sweet potato varieties or cultivars. The study will span for two years. This is part of an MPhil study and results will be shared with the scientific community.


(ISTRC-AB)

319

Spatio-temporal variation in cassava (Manihot spp.) in forest savannah eco-

climatic zone of Nigeria

AdetayoA.O. and and V.O. Aduramigba-Modupe*

Institute of Agricultural Research and Training,

Obafemi Awolowo University,

Moor Plantation, PMB 5029, Ibadan, Nigeria. *(corresponding author e mail: [email protected])

Abstract

Sustainable agricultural growth in most of the developing countries of the tropics implies sustainability of growth in yields through intensive land cultivation. This however requires developing crop varieties with high yield potential as well as effectively tackling soil fertility

constraints. Two years (2009 and 2010) multi-locational field trials were conducted in four

selected locations (Abeokuta, Akure, Ibadan and Oshogbo) within the forest-savannah agroecological zone (AEZ) of Nigeria to investigate the spatial variability in the yield of

cassava. Four varieties (TMS 30572, TMS 91934, TMS 50395 and TMS 30555) were grown in the four locations in a randomized complete block design, with three replications and

harvested after 12 months. Varieties showed differences in root yields across the locations, with Ibadan having the highest. Among the four varieties, TMS 30572 significantly (P>0.05)

produced the highest root yield of 24.5t/ha while TMS 30555 had the least of 16.0t/ha. Our study showed that cassava yield decreased with increasing rainfall distribution in the forest-

savannah AEZ of Nigeria.

Keywords: Cassava, spatial variability, rainfall distribution, root yields.



(ISTRC-AB)

320

Can primary producers sustainably derive higher financial benefits from direct

engagement in mechanized cassava processing?

Bachwengizi1, B.; Towo2 E., Mlingi1, N., Omari1, M., Ranaivoson3, R,

Rabemanantsoa3, N., and Abass 1, A. 1. International Institute of Tropical Agriculture (IITA), East Africa Hub, Plot 25, Light

Industrial Area, Mwenge Coca-Cola Road, Mikocheni B, PO Box 34441,

Dar es Salaam, Tanzania.

2.Tanzania Food and Nutrition Centre, P. O Box 977, Dar es Salaam, Tanzania.

. 3.FOFIFA, Route d’Andraisoro, BP 1690, 101 Antananarivo, Madagascar.

Abstract

Cassava is an important food staple and a substitute for cereals in Madagascar, Mozambique, Tanzania and Zambia. Traditional cassava processing for home consumption is done manually and the products are of lower quality than the requirement of the urban food and non-food

markets. Many efforts have been put in assisting the smallholders to process the cassava

and be properly integrated in the market. We appraised the business performance of smallholder farmers and other value chain actors engaged in primary production, farm gate marketing,

and marketing of fresh roots in the urban markets. This was compared with the financial benefits of farmers who are engaged in small-scale mechanical cassava processing of cassava

products such as chips, starch and flour. Medium-scale processing operations were evaluated against small-scale operations. The study revealed that fresh root trading and marketing

benefit different value chain actors but not equitably. Among all actors, the primary producer

selling the roots at farm gate prices obtain more profit per ton than others. This was attributed to the low capital investments by farmers On the other hand, traders and whole sellers

relatively lower profitability due to high farm gate price and transporting expenditure. Different scales of mechanical processing enterprises have different challenges that affect profitability.

Potential profitability of processing enterprises was remarkably influenced by capacity utilization. In addition, lack of basic infrastructure such as roads and water continue to have

negative effect on the performances of the processing enterprises including their ability to

explore new market options needed to improve business performance.


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321

THE USE OF SOME ALTERNATIVE ENERGY SOURCES [CASSAVA (Manihot

esculenta), SWEET POTATO (Ipomea batatas), AND COCOYAM (Xanthosoma

sagittifolium schott.)] FOR POULTRY AND PIG PRODUCTION AND IT’S

IMPLICATIONS FOR FOOD SECURITY.

Chidimma L. Obi1, *Chika E. Oyeagu2 ,Augustine O. Ani2, Petrus E. Nwakpu1,

Scholastica N. Okongwu1, Patience N. Onu1, Ugochukwu S. Ekwu2, Murphy B.

Enwezor1. 1Department of Animal Science, Ebonyi State University, Abakaliki, Nigeria.

2Department of Animal Science, University of Nigeria, Nsukka, Nigeria.

*Corresponding author: Email:[email protected]

Abstract

In this paper, an attempt was made to discuss cassava, sweet potato and cocoyam as

alternative sources of energy for poultry and pig productions. Cassava, sweet potato, cocoyam and their by-products has been successful in the diets of Poultry and Pigs. Different processing

methods (silage, drying, heat treatment, etc) of these alternative sources of energy (cassava, sweet potato and cocoyam) have increased their potency in the diets of non-ruminant animals

(Poultry and Pigs). The potential constrains and nutritional attributes of these alternative

energy sources should be considered before incorporating them in the diets of poultry and pigs. With adequate processing and inclusion rates in the diet of these alternative energy

sources (cassava, sweet potato and cocoyam), increase in poultry and pig production will be ensured in the humid tropics and this will result in maximum returns to poultry farmers and

availability of chicken, eggs and pork meat to the consumers at affordable prices.

Keywords: Alternative sources, Poultry, energy, Pigs, processing methods, humid tropics.

mailto:Email:[email protected]


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322

DEVELOPMENT OF NRCRI CASSAVA ROOT HARVESTING AID

Ikejiofor, M.C. and Okwesa, C.O

Engineering Research Unit, National Root Crops Research Institute, Umudike

P.M. B, 7006 Umuahia, Abia State, Nigeria


Abstract

The need to reduce the toilage and stoop labour inherent in manual harvesting of cassava roots with traditional tools and the fact that the more complex tractor powered cassava

harvesters are not within the reach of most cassava farmers, are the major considerations

for the design and development of a simple, efficient and affordable harvesting aid for cassava roots. The machine is a hand push type which requires the operator to easily push the machine

along the ridge, and harvest the cassava roots. The machine was developed in the Engineering Research Workshop of National Root Crops Research Institute, Umudike. The overall

dimension of the machine is 115cm x 82cm x 60cm. The machine has four main sections: root lifting, grip adjustment, wheel and the handle. The preliminary testing of the developed

machine was carried out under soft soil condition for different varieties of cassava and the

machine performed satisfactorily very well in lifting the cassava roots with very low percentage of damaged roots. The average harvesting capacity of the machine is 0.38ha/hr.

The machine has easy operational / maintenance procedures.

KEYWORDS: Development, Cassava, Roots, Harvesting, aid



(ISTRC-AB)

323

SEED YAM MULTIPLICATION AND DISTRIBUTION TO FARMERS IN

NIGERIA: THE CONTRIBUTION OF CORAF/WECARD, 2009-2012

J.G. Ikeorgu1 and E.A. Asiedu2

1Regional Coordinator CORAF/WECARD Yam Minisett Commissioned Project

NRCRI Umudike, Umuahia Nigeria and 2Staple Crops Program Manager, CORAF/WECARD

Headquarters, Dakar, Senegal.

Abstract

CORAF/WECARD commissioned a regional seedyam multiplication program in Nigeria, Benin, Togo and Ghana under the USAID-sponsored emergency Global Food Security

Response Initiative in 2009.The purpose was to rapidly multiply and distribute clean seed yams to farmers to reduce the quantum of food yams being used as planting material. In

Nigeria, this project was carried out between 2009 and 2011 by NRCRI and collaborating ADPs and NGOs and farmer organizations in the Nigerian Yam Belt using the yam minisett

of seed yam production technique. Over 600.000 clean seed yams weighing about 200 metric tons were produced in about hectares of land and these were distributed to farmers. On-

farm experience shows that farmers will perform better if inputs are supplied them timely.


(ISTRC-AB)

324

PERFORMANCE OPTIMIZATION OF A CASSAVA PELLETING MACHINE

Kadurumba Chukwuma Henry

National Root Crops Research Institute Umudike Abia State Nigeria

Abstract Cassava Pelleting in most developing countries are usually done manually. This process is very laborious, time consuming and unhygienic. A Pelleting machine has been recommended

because of its low cost, high capacity of providing pelleted cassava as well as relative ease

of operation and maintenance. The machine consists of a screw conveyor for conveying the cassava mash through the dies openings, electric motor, pulley drives and belts. A performance

optimization of the system was carried out to maximize the solid product recovery, efficiency and throughput of the machine. Mathematical models were developed using dimensional

analysis. The independent and dependent variables were measured and compared to computed values such as their standard errors, percentage errors and coefficient of determination.


(ISTRC-AB)

325

Determination of the factors of variability of the glycemic index of yam (Dioscorea

cayenensis-rotundata)

Nestor Kouakou Kouassi1 (E-mail: [email protected]), Georges

GnomblessonTiahou2 and Georges N’Guessan Amani1

1- Laboratory of Biochemical and Technology of Tropical Products, Faculty of Foods Sciences

and Technologies, University of Nangui Abrogoua, Abidjan, Cote d’Ivoire

E-mail: [email protected] 2- Laboratory of Medical Biochemical, Faculty of Medical Sciences, University Felix Houphouet-

Boigny of Cocody, Abidjan, Cote d’Ivoire


Abstract Yam (Dioscorea cayenensis-rotundata) is a foodstuff commonly consumed in Côte d’Ivoire.

This species contains many varieties which have nice organoleptic and textural properties. Because of their richness in carbohydrate and their relative sweetness, clinicians warn

diabetics not to eat this food. To find scientific explanations to these recommendations and formulate appropriate dietary guidelines, this study based on glycemic index measurement of

yam was conducted. The study showed that varieties of yam, whatever their cooking either boiled or baked, fit with recommendation to diabetics due to their relatively low glycemic

index (51-70). The progressive regression modeling to research the main parameters of yam composition that influence their glycemic index have shown that the variability of glycemic

index is not linked to their sweetness (sugars content), but to intrinsic characteristics of

starch of each variety before and after cooking. These characteristics are the amylose content, the distribution and the size of starch granules. These data showed differences in clinical

interest of different yam varieties and will be useful for dietary advice to diabetic subjects and clinicians in Côte d’Ivoire and countries sharing similar food tradition.

Key-words: Yam, Glycemic index, Modeling, Progressive regression, Starch






(ISTRC-AB)

326

Effect of some plant extracts and pesticides in the control of Bacterial Leaf Blight disease of Colocasia esculenta caused by Xanthomonas campestris in Umudike,

Abia State Nigeria

Opara, E. U.1, Isaiah, E. C. 1, Eze, E. C.1, Okolo C. C.2, Ezeaku, P. I2., Chukwudi, P. U.* 3, Ezeudo, V.

C.2, Osadebe, V. O.3, Okechukwu, E. C.3, Amuji, C. F.3 and Imegwu, C.3

1 Department of Agronomy, Micheal Okpara University of Agriculture Umudike, Abia State 2 Department of Soil Science, University of Nigeria, Nsukka, Enugu State

3 Department of Crop Science, University of Nigeria, Nsukka, Enugu State

*Corresponding author’s e-mail: [email protected]

Abstract

A pot trial was conducted in the screen house of National Root Crops Research Institute (NRCRI), Umudike to determine the efficacy of some plant extracts and pesticides in the control of bacterial leaf blight of cocoyam (Colocasia esculenta). The treatments employed

include: Lemon grass (Cymbopogon citrates), Black pepper seed (Piper guineense), orange

peel (Citrus sinensis), streptomycin sulphate (bactericide), copper oxychoride (fungicide) and sterile water (control). The experiment was laid in complete randomized design (CRD)

and replicated six times. The materials used were first made into cold water aqueous extracts and diluted to 10% concentration (w/v). Application on leaves were made using hand sprayer

at two weeks interval. Data obtained showed that Citrus sinensis peel had the least disease score (1.17cm) which differed significantly from the rest of the treatments at P d” 0.05, it

was followed by piper guineense (1.33cm). All the extracts tested proved superior to the

control (sterile water) and were at a par with the two pesticides tested. Copper oxychloride gave 1.67cm and streptomycin, 1.83cm in reducing disease and enhancing yield better than

the control but different from the extracts.



(ISTRC-AB)

327

Optimization of Growth and Amylase production by Aspergillus flavus

grown on cassava peel Sani , A. 1

Department of Microbiology,

University of Ilorin, Ilorin,

Nigeria.


Oyewale, Mojeed Oladapo 2

Department of Applied Science,

Osun State Polytechnic, P.M.B. 301,

Iree, Osun State.


Tel: 234 -8037746805

Abstract Aspergillus flavus demonstrated the ability to produce considerable growth and amylase production. Cassava peel induces high amylase production with maximal amylase activity at

2% W/V. An initial linear increase in amylase activity with increase in substrate concentration was obtained up to 2% W/V.

The maximum growth and amylase production was obtained on the sixth day of incubation at a ph of 7.0, temperature of 29 ± 1oC and 80 Rev..per.minute. it is concluded from this work

that cassava peel may serve as an alternative carbon substrate for large scale cultivation of A flavus for amylase production.

Keywords: Cassava peel, amylase activity growth, substrate concentration Aspergillus

flavus




(ISTRC-AB)

The use of yam bean Pachyrhizus erosus var EC KEW storage root in the African

giant snails (Achatina achatina) feeding in Benin

S.C.B. POMALEGNI11; K.K.C. KINGUELEOUA2 ; P.Y. ADEGBOLA3; S.E.P MENSAH1 ; M.S.E.

GUEDOU1 ; M. M. A. ANATO4 ; M. DAHOUDA4 ; G.AMENSAH1. 1 Laboratoire des Recherches Zootechnique, Vétérinaire et Halieutique (LRZVH), Institut

National des Recherches Agricoles du Bénin (INRAB), 01 BP 884 Recette principale,

Cotonou, Bénin 2 Université Africaine de Technologie et de Management GASA formation, Département de

Production animale, 04 BP 1361 Cotonou. 3 Programme d’Analyse de la Politique Agricole (PAPA), Institut National des Recherches

Agricoles du Bénin (INRAB), 01 BP 128 Porto-Novo 4 Université d’Abomey-Calavi; Faculté des Sciences Agronomiques, Département de Production

Animale, BP 526 Cotonou

Abstract

The cost of feeding in breeding continues to increase. This indicates the need to explore the use alternative feed ingredients. The objective of the study is to enhance yam bean in the diet

of giant snails. A total of 216 giant snails average body weight of 80 g were used. Six rations R0, R14, R28, R56 and R70 composed of plants of Talinum triangulare and Tridax

procumbens, green papaya, yam bean and kaolin were used to feed the giant snails for 2 months. The experimental design was a randomized complete block design with 6 treatments

and 3 replications. Each diet was tested in three groups of 12 each giant snails. The distribution and the collection of the refusal food were weekly done. Weighing giant snails and shellfish

measurements were bi-weekly. The results showed higher weight gains in giant snails fed

with rations containing yam bean. The best weight gain (13.42 ± 4.46 g) and the best dietary intakes (1.07 ± 0.33 g DM / d) were obtained with ration R42. Best shellfish growth in length

(2.49 ± 1.69 mm) in diameter (5.20 ± 2.48 mm), width (2.45 ± 0.75 mm) and the rate of lay highest (975%) were obtained with ration R56.Should be advised farmers not to exceed

42% of yam bean in the diet of giant snails.

Keywords: INRAB, ration, yam bean, Achatina achatina, weight performance, shellfish.

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