ASDA 2019 - Department of Agriculture Sri lanka

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ASDA 2019

Annals of the Sri Lanka Department of Agriculture

VOLUME 21

EDITORS

D.S.P. Kuruppuarachchi (Editor in Chief)B.V.R. Punyawardena

S.P. NissankaJ.K.A. Hettiarachchi

S. WasalaD.M.J.B. Senanayake

W.A.R.T. WickramaarachchiM.G.D.L. Priyantha

2019

Department of AgricultureSri Lanka

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The responsibility for this production rests with the Department of Agriculture, Sri Lanka (DOASL).

All rights reserved. Except for quotation of short passages for the purpose of criticism and review, no part of this publication may be reproduced, stored in retrieval systems, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of the Director General of Agriculture. The DOASL does not require payment for the non-commercial use of its published works, and hopes that this copyright declaration will not diminish the bona fide use of its research findings in agricultural research and development.

Annals of the Sri Lanka Department of Agriculture. 2019. Volume 21.© Department of Agriculture, Sri Lanka.

ISSN 1391 – 6947

This book was prepared on the desktop publishing system at the ASDA Secretariat, P.O. Box 21, In-Service Training Institute, Department of Agriculture, Gannoruwa, Sri Lanka and printed by the Publication Unit of the Department of Agriculture, Peradeniya, Sri Lanka.

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TABLE OF CONTENTSForeword ………………………………….……………...………. xii

Abstracts of Papers Published/Forthcoming Tropical Agriculturist, the Journal of the Department of Agriculture, Sri Lanka

Effect of storage on physiochemical parameters and Aflatoxin production in non-roasted chilli powder in local markets

S.M.A.C.U. Senarathne, R.R.M.K.T. Rathnayake, B.A. Perera, K.G.H.S. Peiris, D.K. Wijerathne, K.W.P.D. Karandawala, H.M.N.D.B. Hennayake, D.N. Hettiarachchi and S.D. Rebeira ..... 1

Assessment of agricultural biodiversity through participatory approachM.C. Millawithanachchi, D.P.P. Liyanage, B.N. Samaranayake and A.P. Bentota .................................................................................... 2

Biology and management of Harpedona marginata Distant (Hemiptera: Miridae): A pest of Dioscorea species in Sri Lanka

P.H. Ranaweera, S. Rathnamalala, S. Nanayakkara, M. Ranathunga and D. Galanihe ............................................................................. 3

Occurrence, taxonomic identification and life cycle of Fall Army Worm (Spodoptera frugiperda J.E. Smith) in Sri Lanka

M.T.M.D.R. Perera ........................................................................ 4

Identification of drought prone areas in Sri Lanka using multi temporal satellite data

A.U. Iddawela, H.K. Kadupitiya, S.H.S.A. de Silva, B.V.R. Punayawardena, W.M.W. Weerakoon, N.D.K. Dayawansa, H.M.A.H. Uduwerella and D.G.S.D. Gunawardena ...................... 5

Hyperspectral remote sensing for prediction of soil propertiesH.K. Kadupitiya, R.N. Sahoo, V.K. Gupta, D.G.S.D. Gunawardena,N. Ahmed and S.S. Ray ................................................................... 6

Detection of pesticide residues in imported and locally-grown perishables through gas chromatography and mass spectrometry

P.W.Y. Lakshani, J.A. Sumith, M.K.L.K. Rajapaksha, W.P.A.P. Dhanapala and W.R.W. Wimalasena ................................ 7

A new promising early maturing groundnut (Arachis hypogaea L.) accession (KCGN -1) suitable for Dry and Intermediate zones of Sri Lanka

S.J. Arasakesary, R. Gugapriya and A. Amirthalojanan ................ 8

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Evaluation of livelihood improvement of women engaged in “Helabojun” outlets

N.P. Liyanage, S. Mathangaweera, V.G.S. Nilantha, W.M.U. Palipana and J.W.L. Surangi .......................................................................... 9

Determination of harvesting indices and harvesting stage of Annona muricata L. (Soursop)

M. Bulathkandage, J.P. Eeswara, T. Madujith, R. Gunawardena, K.D. Chathura and R. Jayapala ..................................................... 10

Effect of El Nino Southern Oscillation (ENSO) events on inter-seasonal variability of rainfall in Wet and Intermediate zones of Sri Lanka

A.B. Abeysekera, B.V.R. Punyawardena, B. Marambe, I.M.S.P. Jayawardena, V.N.M.Wickramasinghe, E.D.D.L. Senarathnaand W.M.V.S. Wijerathna ................................................................ 11

Effect of canopy thermal changes on pollen fertility and yield as influenced by time of planting and water stress imposed at reproductive phase of rice

L.C. Silva, W.M.W. Weerakoon, H.G.P.B. Dharshana, B.M.M.P. Basnayaka, M. Yoshimoto and P. Mahindapala ............. 12

Evaluation of management strategies of Tuta absoluta (Lepidoptera: Gelechiidae) in tomato

T.K.A.I. Hadji, K.P. Somachandra, S.S. Weligamage, K.M.D.W.P. Nishantha, N.S. Senanayake, K.D.M. Kularathne, H.G.C.W. Gamage, A. Dharmasena, J.P. Marasinghe and S.D.K. Priyadarshani ..................................................................... 13

Influence of plant growth regulators and foliar nutrients on growth and yield of chilli

H.M.P.T.K. Hettigedara and G.H.K. de Silva ................................. 14

Weed dominance and status of herbicide resistance in Ischaemum rugosum in direct seeded rice in the Dry zone

H.M.S. Herath, R.F. Hafeel, N.P. Manamperi, R.M.U.S. Bandara,B. Marambe and V.R. Kumar .......................................................... 15

Consumer willingness to pay for commodities certified under Sri Lanka Good Agriculture Practices (SL-GAP)

A.S.M. Roshan and M. Burton ............................................... 16

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Assessment of technical efficiency of maize production in Sri LankaJ.K. Galabada, W.M.U. Palipana and W.M.S.K. Weerasinghe ...... 17

Agronomic practices to enhance crop establishment, grain yield and weed suppression in flooded-direct seeded rice

T. K. Illangakoon, B. Marambe, R.S.K. Keerthisena, A.P. Bentota, C.H. Piyasiri, J.M.N.P. Somarathne, W.U.S. Geethika and V. Kumar ......................................................................................... 18

Assessment of existing fertigation protocols in protected culture of vegetable crops in relation to marketable yield

H.R.U.T. Erabadupitiya, J.K. Galabada and W.A.P. Weerakkody .. 19

Identification of the causal pathogen of bacterial wilt disease in cucurbitaceous crops and bean and its alternative weed hosts in Sri Lanka

W.A.P.G. Weeraratne and D.M.K.K. Dissanayake ......................... 20

Spatial variation of soil properties in paddy fields of Polonnaruwa district

W.M.U.K. Rathnayake, D.N. Sirisena, K.A. Renuka, S. de Silva, A.M. Piumika and A.M.R.S. Atapattu ............................................. 21

Influence of staggered cultivation and weather parameters on the outbreak of rice yellow stem borer (Scirpophaga incertulas Walker) in Polonnaruwa district of Sri Lanka

L.D. Galanihe, D.M.O.K.B. Dissanayake, A.A.F. Rizvana, E.D.M. Wimaladharma and R.A.N. Sanjeewani ............................. 22

Evaluation and characterization of locally developed maize inbred lines for agro-morphological traits in Sri Lanka

W.M.R. Kumari, N.A.P.S.G. Upasantha, D.M.J.K. Dissanayake and W.A.U. Priyadarshani ..................................................................... 23

Study on possibility of enhancing germinability of “Veralu” (Elaeocarpus serratus L.) seeds by pre-treatments and germination variability of different accessions

M.K. Thantirige, K.A.S.C. Kumarapperuma, M, A.R.L. Perera and U.N. de Silva ................................................................................... 24

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Adaptability of promising CIMMYT maize hybrids across diverse maize growing environments in Sri Lanka

W.M.R. Kumari, D.C.S.M.I. Wijewardhana, N.A.P.S.G. Upasantha, W.M.N.D. Gunathilake, T. Karunainathan, W.M.W. Weerakoon and B.S.Vivek .................................................. 25

Tomato powder as a substitute for preserved tomato pulp in sauce production

D.N. Hettiarachchi, H.M.P.B. Somarathne, W.A.J.P. Wijesinghe, D.L.C.N. Hitigedara, R.A. Wijerathna, H.R.P. Fernando and S.M.A.C.U. Senarathne ................................................................... 26

Review Article

Management of chilli root knot nematodes (Meloidogyne spp.) in Sri Lanka

S. Rajeshkanna, K. Holmes and S. Toepfer ..................................... 27-41

Short Communications

Effect of harvesting time on the seed yield and quality of common bean for seed production (Phasiolus vulgaris L.)

Y.L.B. Pavithrani and H.D. Fonseka .............................................. 42-47

Response of selected rice varieties for salt stress at different stages of life cycle

R.M.N.H. Senanayake, H.M.V.G. Herath, I.P. Wickramesinghe,U.A.K.S. Udawela, H.M.L.U. Sandaruwan, D.G.K.P. Wijerathna and W.G.Wijepala ........................................................................... 48-53

Toxicity of herbicide, Diuron 480 g/l SC to cultivated riceR.M.U.S. Bandara, B. Marambe, W.M.U.B. Wickrama, Y.M.S.H.I.U. de Silva, H.M.M.K.K.H. Dissanayaka, D.M.C.B. Dissanayake and P.R.T.E.W.M.R.B. Ekanayake ............. 54-57

Effect of stem pruning and fruit thining on yield and quality of bell pepper in poly house

I.C.S. Edirimanna, H.M.V.S. Dharmasena, S.M.U.I. Samaraweera and A.M.R. Darshana ...................................................................... 58-61

Influence of drip irrigation regimes on tuber yield of King yam (Dioscorea alata. L.) in Red Yellow Latosol soils

S.J Arasakesary and A. Amirthalojanan .......................................... 62-66

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The cyanogenic potential of roots and leaves of released cassava (Manihot esculenta Crantz) varieties in Sri Lanka

N.L.A.T.S. Nanayakkara, G.G.C. Premalal, S.M.S A. Sumathipala,E.R.I.B.N.N. Jayalath and N.N. Rajapaksha ................................... 67-70

Effect of different pre-treatment to break seed dormancy of stored bitter gourd seeds in refrigerated condition

H.M.P.S. Kumari, P.U. Nisansala, E.P. Wijewardhane and D.P. Sumanasinghe .......................................................................... 71-75

The effect of meteorological factors on the population dynamics of fruit fly

A.S. Pushpakumari and M.G.N.E. Mahagollage ............................. 76-79

Management of chilli thrips (Scirtothrips dorsalis) through application of calcium phosphate solution

S. Rajeshkanna, S. Mugunthini and R. Jathukula ............................ 80-83

Effect of chloromaquat chloride 50% SL. application on growth and yield of capsicum (Capsicum annum L.)

K.A.D.S.D. Kahandawaarachchi, B.M.A.U.K. Bandara and A.R. Jayasena ................................................................................. 84-88

Re-evaluation of the recommended spray volume to control brown plant hopper (Nilaparvata lugens Stål) at outbreak situation using ethiprole 100 g/l SC and Thiocyclam hydrogen oxalate 50% SP

S.R. Sarathchandra, J.H.T.G. Kavindya, A. Mannakkara, M.A.B.R.P. Bandaranayake, P.G.K. Perera and A.G.N.H. Madhuvanthi ................................................................... 89-93

Profitability analysis of paddy farming in Sri LankaN.L. Sudheera and B.G.C.A. Gamlath ............................................ 94-97

Effect of aphids and whiteflies infestation on potato yield in Up Country Wet zone of Sri Lanka

H.A.S.N. Hettiarachchi, M.M. Kumarage and K.M.C.R.K. Bandara ...................................................................... 98-101

Performance and comparative advantage of pineapple export from Sri Lanka

P.S.R. Premarathna ......................................................................... 102-105

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Usage of potato micro tubers in slow growth conservation E.S.C. Edirisinghe, K.M.G. Kulathunga and C.H. Denagamage ... 106-109

Response of rice to site specific application of fertilizer W.M.U.K. Rathnayake, M.G.N. Rupasinghe, D.N. Sirisena, W.M.N. Wanninayake, K. Karunarathne and H.A.D.I. Maduroshika ..................................................................... 110-114

Growth and yield performance of different planting materials of potato variety granola in hydroponic and aeroponic systems

H.A.S.N. Hettiarachchi, A.M.N. Amarasingha, A.G.C. Babu, K. Dayani, A. P. Rathnakumara and M. Premalatha ...................... 115-118

Assesment of native Trichoderma species against Rigidoporus and Fusarium isolates pathogenic to jak trees

M. Kuruppu, N.S. Jayawardhana and R.K. Nilmini ....................... 119-123

Weed seed entry to Sri Lanka with imported vegetable seedY.M.H. Liyanage, S.M.A.R. Abekoon, P.K.K.Wijayanthi, K.M.P.D. Karunarathne, H.M.J.C.K. Herath and K.L.M.I. Kondasinghe .................................................................... 124-127

In-vitro multiplication of gac fruit (Momordica cochinchinensis Lour. spreng.)

D.A. Shirani, S.H.C.K. Dharmarathna, A.W. Gaminie and D.A.B.N. Amarasekara ................................................................... 128-132

Factors affecting the satisfaction of agricultural products suppliers at Hadabima authority

M.G.W.S. Kariyawasam and A.S. Rathnayake ............................... 133-137

Use of gliricidia (Gliricidia sepium) leaves as a source for organic nutrient management of watermelon (Citrullus lanatus)

K.A. Renuka, P.G.R.K. Wickramasekara, H.L.G.R. Hewawasam, R.D.M. Ranaweera and K.R.S. Chamarika .................................... 138-141

Species diversity and dominance in Kandyan homegardensA.G. Chandrapala, K.M.A. Kendaragama, I.C. Gunasekara and S.K. Wettasinghe ............................................................................. 142-150

Effect of coloured polythene mulch on growth, yield and quality of carrot var. Lanka carrot

I.C.S. Edirimanna, J.M.D.D.E. Jayamanne, H.M.V.S. Dharmasena, A.M.R. Darshana and S.M.U.I. Samaraweera ............................... 151-154

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Cost benefit analysis on establishing of machinery hiring out centreK.G.C.D.B. Wijesinghe, G.L. Nagahawaththa, R.B.T.M. Radeniya and D.M.B. Priyadarshani ............................................................. 155-158

Abstracts of Poster Presentations

Performance and economic returns of cultivating reed plants (Cyperus corymbosus) under rainfed conditions in paddy fields of Wet zone for Traditional Craft Weaving Industry in Sri Lanka

G.D.A. Priyantha, I. Madhavi and J.N. Silva ................................. 159

Stump suckers as planting materials in cabbage cultivation N.S. Senanayake, K.P. Somachandra, T.K.A.I. Hadji, K.D.M. Kularathna and A. Dharmasena ......................................... 160

Developing a protocol for production of planting materials of apple (Malus domestica) by using tissue culture and graftting

L.G.I. Samanmalie, E.G.A.R. Mallika, K.G.G. Indika, S. Widyaratne and H.M. Senewiratna Bandara .............. ....................................... 161

Value added products from pumpkin (Cucurbita maxima) to reduce post harvest losses and increase farmer income

D.N. Hettiarachchi, D.L.C.N. Hitigedara, H.M.D.K. Jayarathna, R.A.Wijerathna, and S.M.A.C.U. Senarathne ................................ 162

Identification and characterization of soft-rot causing pathogen in Aglonema maria; A key exporting ornamental plant in Sri Lanka

M.H.A.D. Subhashini, C.M. Nanayakkara, L.C.K. Senaratne and D. Piyatissa ..................................................................................... 163-164

Pumpkin incorporated nutritionally rich burger bunH.B. Sasiprabha, S.P. Rebeira, R.M.S.K. Ranathunga, K.G.U.K. Koongahage and A.D. Amaraweera ............................... 165

System for issuing electronic phytosanitary certificates in Sri LankaM.P.M. Senarathne, G.M.S.T. Gajanayake and W.A.R.T. Wickramaarachchi ........................................................... 166

Impact of Permanent Crop Clinic Programme (PCCP) for the management of pest and diseases in Galle district

S.H. Kahingala ............................................................................... 167

Analysis on failure to comply with export phytosanitary requirements by Sri Lanka

G.G.D. Lalani and D.C.H. Kumarasinghe ..................................... 168

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Strategies for sustainable management of Fall Army Worm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) in Sri Lanka

K.N.C. Gunewardena, S.M.A.O. Nadeeshani and P.A.I. Sandaruwani ......................................................................... 169

Introduction of the potential to develop pumpkin (Cucurbita maxima) based food products

H.M.N.D.B. Hennayake, S.M.A.C.U. Senarathne, N.W.K.U. Niranjala, N. Liyanage, K.W.P.D. Karandawala and D.K. Wijerathne ........... 170

Effect of admission qualification on the performance of students of the diploma in agriculture and demand for public sector employment

A.K. Jayawardena ........................................................................... 171

Introducing nutrition labeling for a better choice of Helabojun foodD.S. Rathnasinghe, S. Gunathilaka and U.H.M. Subuddhika ........ 172

Farmer empowerment in Damana Agrarian Service Center of Ampara inter provincial area through small farmer production society approach

J.R. Sudasinghe, U.C.S. Perera, M.F.A. Zaneer, A.B.M. Wijatatunga and P.N.M. Dayarathna .................................................................. 173

Evaluation of moss gel as a low cost solidifying agent to substitute agar in plant tissue culture

S.M. Nagahawaththa, L.I.A. Amarawansha, D.L.D. Lakmali, L.G.G. Indika and P.A. Weerasinghe .............................................. 174

Blyxa octandra (Family: Hydrocharitaceae): A newly emerging aquatic weed in rice fields of Wet zone and Intermediate zone in Sri Lanka

R.M.U.S. Bandara, R.M.N.H. Senanayake, T.K. Illangakoon, S.R. Sarathchandra, W.M.U.B. Wickrama, Y.M.S.H.I.U. de Silva, H.M.M.K.K.H. Dissanayaka, D.G.K.P. Wijerathne, H.M.G.M.K. Weerasooriya, U.G.S.P. Gunasekara, E.M.P. Ekanayake and R.A.S.W. Ranasinghe ................................. 175

Research News

New threaten pest to Annona muricata L.K.A.J.C. Premawardhane, H.K.Kumuduni, W.A.C.K. Wickramasinghe and W.M.C.N.Wijesinghe ................................................................ 176

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Pre-plant, total killer herbicide, Tiafenacil 50 g/l ME: as an alternative for Glyphosate and Paraquat

R.M.U.S.Bandara, D.M.J.B. Senanayake, W.M.U.K. Rathnayake, U.A.K.S. Udawela, J.A. Sumith, H.A.S.N. Hettiarachchi, L.C. Silva, U.S.K. Abeysinghe, W.M.U.B. Wickrama, Y.M.S.H.I.U. De Silva, H.M.M.K.K.H. Dissanayaka, M.R.A.B. Madduma, I.B.J. Bandara, S.Sivanason, P.R.T.E.W.M.R.B. Ekanayake and J.D.H.E. Jayasinghe ................. 177

Phytotoxicity of Herbicide, Florpyrauxifen benzyl 25 g/l EC to cultivated rice

R.M.U.S. Bandara, B. Marambe, D.M.J.B. Senanayake ,W.M.U.K. Rathnayake, U.A.K.S. Udawela, W.M.U.B. Wickrama, Y.M.S.H.I.U. de Silva, H.M.M.K.K.H. Dissanayaka, D.G.K.P. Wijerathne, M.A.R.B. Madduma, R.P. Upali, K.A.K. Premarathna , U.B.U. Attanayaka and U.S.K. Abeysinghe .......................................................................... 178

Adaptability of a newly released Horana Hybrid -01 papaw under Low Country Dry zone condition.

S.J. Arasakesary, S. Rajeshkanna, S. Mugunthini and A. Amirthalojanan .......................................................................... 179

List of Paper Reviewers ............................................................................... 180-184

Instructions to Authors ....................................................................... ........ 185-189

New varieties released by the Department of Agriculture in 2018............ . 190-196

New technology released by the Department of Agriculture in 2019......... 197-207

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FOREWORD

Agricultural research has played a crucial role in increasing food production and will continue to play a major role in future as well. Science based agriculture is essential in enhancing food productivity while maintaining the sustainability of natural resources and the environment. The changing weather pattern, rainfall in particular has posed the biggest risk for the agriculture sector in Sri Lanka. Also, the increasing agricultural labour shortage due to growing reluctance of rural youth to engage in agriculture is another significant challenge towards the sustainability of Sri Lankan agriculture. In order to achieve current food production targets, a paradigm shift is needed from current conventional agriculture towards low water dependant agriculture involving drought tolerant varieties and mechanization.

The impact of agricultural research in Sri Lanka is quite significant and visible. The Department of Agriculture, as the largest and most prominent agricultural research organization of the country provide it’s scientists a forum to share their findings annually at the Annual symposium of the Department of Agriculture (ASDA). The Annals-2019 contains the findings of the research studies conducted by DOA officials during 2014-2019. Out of 103 manuscripts submitted for ASDA-2019, 72 were selected through a thorough reviewing process by ASDA editorial committee involving relevant subject matter experts from universities and other research organizations as independent reviewers.

The editors of the Annals 2019, in collaboration with the editors of the Tropical Agriculturist (TA), a reputed peer-reviewed agricultural journal published by the DOA since 1881 identified 26 full papers to be considered for publication in TA. Therefore, the Annals of the Sri Lanka Department of Agriculture-2019 includes the abstracts of the 26 full papers to be published in TA and 25 manuscripts which were considered better suited as ‘Short Communication’ by reviewers. Annals-2019 contained another 16 abstracts of preliminary studies which were presented in the form of posters at the ASDA 2019. Also, one review article and four research news articles were included in Annals-2019. The research studies included in Annals of ASDA -2019 covered evidence-based studies on all scientific aspects of agriculture including the crop

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science, agricultural economics, biotechnology, agribusiness, pest management, agricultural engineering, agricultural extension, and many more related areas and conducted collaboratively by scientists of different divisions of DOA and other institutes of the National Agriculture System of Sri Lanka including universities and foreign agencies.

We wish to extend our gratitude to all independent reviewers for the excellent cooperation and thank all authors for their friendly and prompt response.

Dr D.S.P. Kuruppuarachchi (Editor in Chief) Dr (Ms) S. WasalaDr B.V.R. Punyawardena Dr D.M.J.B. SenanayakeProf. S.P. Nissanka Dr W.A.R.T. WickramaarachchiMs J.K.A. Hettiarachchi Dr (Ms) M.G.D.L. Priyantha

September 05, 2019

1Annals of Sri Lanka Department of Agriculture 2019. 21

**The full paper of this article will be published in the Tropical Agriculturist Vol: 167 of 2019

Effect of storage on physiochemical parameters and Aflatoxin production in non-roasted chilli powder in local markets

S.M.A.C.U. Senarathne1, R.R.M.K.T. Rathnayake2, B.A. Perera2, K.G.H.S. Peiris2, D.K. Wijerathne1, K.W.P.D. Karandawala1, H.M.N.D.B. Hennayake1,

D.N. Hettiarachchi1 and S.D. Rebeira1

1Food Research Unit, Department of Agriculture, Sri Lanka2Department of Chemistry, Faculty of Applied Sciences, University of Sri

Jayewardenepura, Sri Lanka

AbstractChilli or Capsicum annum is used worldwide in seasoning, coloring and

flavoring food. This experiment was conducted with dried chilli powder to study as to how the physiochemical parameters are altered during storage in local markets. Usually chilli powder tends to degrade its physiochemical composition considerably with storage and the objective of this study was to ascertain what conditions are favorable to maintain the original quality of chilli powder during storage in local markets. The tested parameters were Moisture content, Total ash content, Color, Ascorbic acids, Total phenolics, Antioxidant activity and pH of non-roasted chilli powder. Meanwhile, presence of Aflatoxins was also monitored qualitatively. Room temperature and average supermarket temperature were provided with three light settings, namely normal, direct and the dark box resulting six combination of storage conditions extended for 04 month period. Results revealed that mean moisture content of chilli powder is about 10.19 per cent in storage, while mean ash values around 6.22% and pH values with an average of 4.76. The mean Ascorbic acid content is 21.71 mg/100g whereas average total phenolics is about 36.49 mg/ 100 g (DW). The ASTA color value was 232.84 units. The mean IC50 value is found as 4.26 μg/100g. The interaction among light condition, temperature and brand is found to be significant. Storage in dark boxes resulted negative impacts on presence of Aflatoxin in every sample. Accordingly, the dark storage in supermarket at ambient temperature of 22 °C to 24 °C range was found to be the best storage condition for chilli powder to maintain its original quality.

Key words: Chilli powder, Mycotoxin, Physio-chemical parameters, Storage

2 Annals of Sri Lanka Department of Agriculture 2019. 21


Assessment of agricultural biodiversity through participatory approach

M.C. Millawithanachchi1, D.P.P. Liyanage2, B.N. Samaranayake2 and A.P. Bentota3

1Rice Research Station, Labuduwa, Sri Lanka,2Grain Legumes and Oil Crops Research and Development Center,

Angunakolapellessa, Sri Lanka3Ministry of Agriculture, Rajagiriya, Sri Lanka

AbstractAgricultural biodiversity provides food, animal feed, fuel woods, shelter,

medicine and cultural requirements and the aesthetic beauty for the life style of a particular community. Hence, knowledge on on-farm agricultural biodiversity is important in many aspects to determine the level of management required on biological resources for the better utilization and conservation for future use. Assessment of the agricultural biodiversity of three villages of Thanamalvila Divisional Secretariat, Mahaweva, Kahakurullanpellessa and Sooriyaara in Sri Lanka were carried out using participatory tools such as village transect walks, diversity fairs, four cell analysis and community biodiversity registers during 2012, 2013 and 2014. These participatory tools could be effectively used for the quick assessment of on-farm agricultural biodiversity in the selected three villages. Simpson’s index for diversity (> 0.7) indicated that considerable species and varietal diversity exist within three villages. Cowpea and Yard-long bean had the highest varietal diversity. According to four cell analysis, Pinna mung, Kaha mung, Foxtail millets and Proso millets were grown in few households and in small land area and has categorized as a threatened group. It was recommended to increase the cultivation area of rare and threatened category of crops by introducing diversity blocks and further selection of adaptable varieties through mother and baby trials to increase the varietal diversity.

Key words: Agricultural biodiversity, Community biodiversity register, Diversity fair, Four cell analysis



Biology and management of Harpedona marginata Distant (Hemiptera: Miridae): A pest of Dioscorea species in Sri Lanka

P.H. Ranaweera1, S. Rathnamalala2, S. Nanayakkara1, M. Ranathunga1 and D. Galanihe3

1Horticultural crops Research and Development Institute, Gannoruwa, Sri Lanka2In-service Training Institute, Gannoruwa, Sri Lanka

3Rice Research Institute, Batalagoda, Sri Lanka

AbstractHarpedona marginata Distant (Hemiptera: Miridae) is an emerging pest in

Dioscorea cultivations in Sri Lanka. Pest damages were observed in July to September 2017/2018. Thirty three Dioscorea accessions were evaluated at Horticultural Crops Research and Development Institute (HORDI), Gannoruwa and all evaluated accessions were susceptible for this pest. The study was focused on morphological characterization, information on life cycle and chemical control measures of the pest. Male and female insects are morphologically very similar. Head and body have black, 3- 4 mm in length. White colour patches were found on infested leaves. In severe infestation, leaves become brownish colour. H. marginata took 26.0 ± 0.47 days to complete its life cycle at 27 0C. Potential insecticides to control H. marginata in laboratory bioassay were 0.75% Neem formulation 5 ml/l (Lakgro neem), Neem seed water extract (30 g/l), Thiamethoxam 25% WG, 0.5 g/l (Actara), Imidacloprid 20% SL, 1 ml/l (Admire) and Thiamethoxam 25% WG + Cloranthraniliprole 20%SC 0.25 g/l (Vertako). Thiamethoxam 25% WG and 0.75% Neem formulations were shown positive results in controlling both adults and nymphal stages of H. marginata in field screening.

Key words: Life Cycle, Morphology, Neem



Occurrence, taxonomic identification and life cycle of Fall Army Worm (Spodoptera frugiperda J.E. Smith) in

Sri Lanka

M.T.M.D.R. Perera

Plant Protection Service, Gannoruwa, Peradeniya, Sri Lanka

AbstractFall Army Worm (Spodoptera frugiperda J.E. Smith) is an alien, invasive very

voracious pest attacking maize crop and about 80 other plant species. It is native to the tropical regions of the western part of the world from the United States to Argentina and migrated to African continent in 2016 and to India in August 2018. First complain of hitherto an unknown pest damaging maize crop was received from Iddapola, Mahaoya in Ampara District on 29 October 2018 and the samples of eggs and larvae were collected from a farmer field. They were reared in the laboratory in insect cages till the adult stage and based on morphological features, it was suspected to be the Fall army Worm. Mated adults were transferred to new insect cages and the second generation adults and sixth instar larvae were identified based on taxonomic features and confirmed as Fall Army Worm, S. fruigiperda. The life cycle study indicated that the incubation period of eggs ranges from 2-3 days, the larval period 14-19 days, the pupal period 9-12 days and the total life cycle of male and female Fall Army Worm is 32-43 days and 34-46 days, respectively.

Key words: Fall Army Worm, Life cycle, Sixth instar larvae, Spodoptera frugiperda, Taxonomy



Identification of drought prone areas in Sri Lanka using multi-temporal satellite data

A.U. Iddawela1, H.K. Kadupitiya1, S.H.S.A. de Silva1, B.V.R. Punayawardena1, W.M.W. Weerakoon2, N.D.K. Dayawansa3, H.M.A.H. Uduwerella1 and

D.G.S.D. Gunawardena1

1Natural Resources Management Centre, Peradeniya, Sri Lanka2Department of Agriculture, Peradeniya, Sri Lanka

3Department of Agriculture Engineering, Faculty of Agriculture, University of Peradeniya, Sri Lanka

AbstractDrought is an insidious hazard of nature with a slower onset and is often

misunderstood as a minor weather hazard. Nevertheless, it has become a common and recurring natural disaster in Sri Lanka during recent times affecting the livelihood of rural agricultural sector in particular. This study has attempted to identify spatial patterns of drought prone areas to improve drought preparedness and strengthen appropriate drought management strategies. Drought prone areas for each month were produced and by aggregating them, a resultant composite map was developed showing overall drought prone possibilities across Sri Lanka.The results revealed that drought is a less frequent phenomeon in January in Sri Lanka except in some parts of Western and Southern provinces. Drought conditions at most of the North-eastern parts of the Dry zone areas of Sri Lanka could be seen during May to September with a peak drought during August and September in the Uva and Eastern provinces. Jaffna, Killinochchi and Batticaloa districts can be categorized as severe drought prone districts of the country. Accuracy of the composite map was checked using historical records of Disaster Management Centre, Sri Lanka from 2001-2017 at the DS Division level. The accuracy was 77.01%, Type I Error was 22.09% and Type II Error 0%. The Chi-Square Test showed high accuracy levels (p<0.05) suggesting that the vegetation condition approach is appropriate for drought assessment in Sri Lanka.

Key words: Drought prone areas, MODIS, Normalized difference vegetation index, Vegetation condition index



Hyperspectral remote sensing for prediction of soil properties

H.K. Kadupitiya1, R.N. Sahoo2, V.K. Gupta2, D.G.S.D. Gunawardena1, N. Ahmed2 and S.S. Ray2

1Natural Resources Management Centre, Department of Agriculture, Peradeniya,

Sri Lanka2Indian Agriculture Research Institute, New Delhi, India

AbstractThis study was conducted to evaluate Hyperion satellite data along with

field and laboratory spectral observations for predicting soil properties. The spectral observations of in-situ soils in the study area were taken at 85 random locations and soil samples of each location were scanned under laboratory conditions for recording reflectance spectra. Out of 242 bands of Hyperion satellite data, error free 158 bands were used for the study. Laboratory and field measured reflectance data were resampled to obtain Hyperion comparable 158 bands. Three data sets were used for developing prediction models for eight soil properties; Soil Organic Carbon content (SOC), CaCO3, Mineralizable Nitrogen (N), available Phosphorous (P), available Potassium (K), sand %, silt % and clay %. Prediction models were developed using stepwise regression approaches. The study showed that the corrected Hyperion spectral pattern was comparable with ground-based spectra. Reflectance and derived spectra were used for models and derivatives were found as better predictors of soil properties than that of reflectance or absorbance, irrespective of the platform. Although the predictability of Hyperion reflectance is lower than that of field and laboratory reflectance, some soil properties such as Silt, SOC and CaCO3 could still be predicted with reasonably good accuracy (R2 > 0.5) with Hyperion data.

Key words: Field Spectra, Hyperion, Lab-spectra, Soil property prediction



Detection of pesticide residues in imported and locally-grown perishables through gas chromatography and

mass spectrometry

P.W.Y. Lakshani, J.A. Sumith, M.K.L.K. Rajapaksha, W.P.A.P. Dhanapala and W.R.W. Wimalasena

Office of the Registrar of Pesticide, Kandy Road, Getambe, Sri Lanka

Abstract Food safety is a crucial issue worldwide. Consumers frequently complains to

relevant authorities about health concerns associated with locally grown vegetables and in particular imported fruits. Pesticide residues in 111 samples, including 6 different crops, i.e., 27 samples of potatoes, 22 samples of oranges, 34 samples of onions, 13 samples of chillies, 12 samples of apples and 3 samples of grapes from selected growing areas and imported consignments at Orugodawatta, Sri Lanka were evaluated against 12 pesticides (Pirimiphos methyl, Dicofol, Pendimethalin, Quinalphos, Pretilachlor, Bifenthrin, Diazinon, Chlorphyrifos, Fipronil, Prothiophos, Oxyfluorfen, Tebuconazole). Fifty four imported samples including 28 samples from India, 14 samples from China, 5 samples from Pakistan, 1 sample from Bangladesh, 1 sample from South Africa, 1 sample from Australia, 2 samples each from USA and France and 57 of local samples were collected during May to December 2017 and samples were extracted according to the quick, easy, cheap, efficient, rugged, safe (QuEChERS) method as per Association of Official Analytical Chemist (AOAC) official method 2007.01, applying a single step buffered acetonitrile extraction. Salting out liquid-liquid partitioning from water in the sample with MgSO4 and clean-up were done by dispersive solid-phase extraction. Concentrated samples were analysed by Gas Chromatography Mass Spectrometry (GC-MS) in selective ion mode (SIM) and the presence of pesticides was confirmed with retention time (RT) and mass spectrum (MS). Matching of RT and MS data of the sample peak with that of the certified reference materials (CRM) gave unambiguous identification of the pesticides presence in the sample. Recovery studies at three spiking concentration levels, i.e. 1 Limit of Quantification (LOQ), 5 LOQ and 10 LOQ varied from 70 % to 110 % with a Relative Standard Deviation (RSD) below 20%. Among the imported samples that were positive for pesticide residues, Diazinon, Chlorphyrifos, Fipronil, Oxyfluorfen, Tebuconazole were detected in 5.6%, 1.9%, 14.8%, 16.7 %, 13.0% samples, respectively and among the local samples that were positive for pesticide residues, Pendimethalin, Pretilachlor, Bifenthrin, Chlorphyrifos, Fipronil, Oxyfluorfen, Tebuconazole were detected in 2.8%, 2.8%, 22.2%, 1.8%, 12.3%, 17.5% and 7.01% respectively. The results revealed that a presence of pesticide residues in both imported and local samples. Continuous monitoring of pesticide residues in imported perishables and those grown in Sri Lanka with spatial tagging need to be executed to obtain sufficient evidences to make conclusive policy decisions to ensure consumer safety.

Key words: Gas chromatography, Mass spectrometry, Pesticide residues, LOQ, QuEChERS



A new promising early maturing groundnut (Arachis hypogaea L.) accession (KCGN -1) suitable for Dry and Intermediate

zones of Sri Lanka

S.J. Arasakesary, R. Gugapriya and A. Amirthalojanan

Regional Agriculture Research and Development Centre, Iranaimadu Junction,Kilinochchi, Sri Lanka.

AbstractA considerable number of farmers still prefer to cultivate the groundnut land

race Mullaithivu local because of its taste and ability to sustain in poor management conditions under rainfed farming systems. Five lines were developed and purified from stocks of this cultivar collected from Mullaitivu (MU) and Muthaiyankattu (MUK).These lines were selected based on the pod shape, peak at the distal end of the legumes, and the presence of only two seeds per pod. Selected lines were tested in preliminary yield trial (PYT) and in National Coordinated Variety Testing (NCVT) trials, with the recommended varieties Indi and Tikiri as controls. Recommended package of practices and standard plot size (1.8 x 3 m) were adopted in all experiments across all locations. KCGN-012-1 has given the highest yield with overall rank of 2 and 1 in NCVT trials during Maha 2014/15 and Maha 2015/16 seasons, respectively. It has also given rank 1 and the highest average yield (3.9 t/ha) under Variety Adaptability Trial (VAT) conducted in five locations. It also bears preferred nutritional quality and acceptable taste as a table variety. Thus, a short duration high yielding table purpose accession KCGN-01 (KCGN-012-1) developed at RARDC Kilinochchi is a promising groundnut accession that can be recommended for cultivation in Dry and Intermediate zones of Sri Lanka.

Key words: Groundnut, Adaptability, Promising accession, Early maturity.



Evaluation of livelihood improvement of women engaged in “Helabojun” outlets

N.P. Liyanage1, S. Mathangaweera1, V.G.S. Nilantha1, W.M.U. Palipana1 and J.W.L. Surangi2

1Socio Economic and Planning Center, Department of Agriculture, Peradeniya, Sri Lanka

2Grain Legumes and Oil Crops Research and Development Center, Angunakolapelessa, Sri Lanka

AbstractHelabojun (Local food) is a concept originated in Department of Agriculture

(DOA) to encourage women for profitable self-employment and promote local/indigenous food consumption in urban and semi-urban areas of the country. These Helabojun hal provides a range of indigenous foods and drinks at a reasonable price under one shelter that makes available safe and nutritious foods for customers. This program has also become a coping strategy for women to improve their livelihood. Based on Sustainable Livelihood Framework (SLF) and primary data collected from five Helabojun hal, a study was conducted to measure livelihood improvement gained by women through participation Helabojun concept. Livelihood outcomes were measured by developing a Livelihood Outcome Index (LOI). Paired sample t-test was employed to compare mean income before and after engagement in Helabojun hala. Independent variables recorded at the ratio scale were correlated with dependent variable through Pearson’s correlation to evaluate the second objective. The LOI indicated that 46%, 30% and 24% of the women have achieved High, Moderate and Low livelihood improvement levels, respectively. Family size, years of schooling, years of experience and working days per month were positively correlated with the livelihood improvement levels achieved by women at p≤0.05. This study reveals that household characteristics influences livelihood improvement levels of women engaged in Helabojun outlets. Additional information collected during the study has also revealed that provision of adequate space and sanitary facilities at Helabojun premises is advantageous in attracting more customers.

Key words: Indigenous foods, Livelihood improvement, Women and household well-being.



Determination of harvesting indices and harvesting stage of Annona muricata L. (Soursop)

M. Bulathkandage1, J.P. Eeswara2, T. Madujith 3, R. Gunawardena1, K.D. Chathura1 and R. Jayapala1

1Fruit Research and Development Institute, Kanawila, Horana, Sri Lanka2Department of Crop Science, Faculty of Agriculture, University of Peradeniya,

Sri Lanka3Department of Food Science, Faculty of Agriculture, University of Peradeniya,

Sri Lanka

AbstractHarvesting time plays a decisive role in ripening, storage and table quality of

Soursop (Annona muricata L.) fruits. This study was conducted with the objective of developing a harvesting index based on the change of selected physical and biochemical parameters at different growth stages of fruits. Growth curves for 3 accessions of A. muricata were developed by using weekly changes of fruit length and circumference. Physical, physiological, biochemical and chronological parameters of the fruit were tested at seven identified stages. Growth curve was identified as double sigmoid with long and highly variable quiescent phase. As harvesting indices, fruit skin color (L*= 42.45, b*=25.72, and h*=100.4, Yellow green group -YG 144A of Royal horticulture color chart) and number of spurs per 2.3 cm2 (3-4) were identified at stage 5 with high total soluble content (17.4 Brix0) and longer storage life of 5.2 days.

Key words: Soursop, Growth curve, Maturity indices, Physicochemical parametrs.



Effect of El Nino Southern Oscillation (ENSO) events on inter-seasonal variability of rainfall in Wet and

Intermediate zones of Sri Lanka

A.B. Abeysekera1, B.V.R. Punyawardena1, B. Marambe2, I.M.S.P. Jayawardena3, V.N.M. Wickramasinghe1, E.D.D.L. Senarathna1 and W.M.V.S. Wijerathna1

1Natural Resources Management Centre, Department of Agriculture, Peradeniya, Sri Lanka

2Department of Crop Science, Faculty of Agriculture, University of Peradeniya, Sri Lanka

3Department of Meteorology, Colombo, Sri Lanka

AbstractOcean-atmospheric teleconnections such as El Nino Southern Oscillation

(ENSO) are important climatic determinants in studying inter-and intra-seasonal variability of rainfall. The ENSO takes place in the central eastern equatorial Pacific Ocean. Warm and cold phases of ENSO cycle are termed as El Nino and La Nina, respectively. As it influences the global climate, the present study was carried out to find out such teleconnections in the seasonal rainfall climatology of Wet and Intermediate zones of Sri Lanka during four rainfall seasons using daily rainfall time series from 1976-2018 (February) for 15 locations scattered throughout Wet and Intermediate zones. El Nino, La Nina and neutral years during the study period were identified using Oceanic Nino Index (ONI). The mean cumulative rainfall of ENSO years were statistically compared with the remaining neutral years. The results clearly revealed a significant reduction of rainfall during both First Inter Monsoon (FIM) and North East Monsoon (NEM) seasons during El Nino years. The Second Inter Monsoon (SIM) season showed a positive anomaly of rainfall during the El Nino years. However, the effect of El Nino condition on the Southwest Monsoon season (SWM) was not consistent across both climatic zones under review. During La Nina conditions, an above normal rainfall was observed in the FIM, SWM and NEM seasons where the strongest correlation was evident during the NEM season. The SIM season has shown a below normal rainfall during the La Nina period. These teleconnections can be effectively used as a forecasting tool of seasonal rainfall in the two climatic zones of the country and thereby minimizing climate-related risks in agricultural and hydrological operations.

Key words: El Niño Southern Oscillation, Oceanic Nino Index, Rainfall variability, Wet and Intermediate zones



Effect of canopy thermal changes on pollen fertility and yield as influenced by time of planting and water stress imposed at

reproductive phase of rice

L.C. Silva1, W.M.W. Weerakoon2, H.G.P.B. Dharshana1, B.M.M.P. Basnayaka1, M. Yoshimoto3 and P. Mahindapala1

1Field Crops Research & Development Institute, Mahailluppallama, Sri Lanka2Department of Agriculture, Peradeniya, Sri Lanka

3National Institute of Agro- Environmental Sciences, Tsukuba, Japan

AbstractDrought and heat stress at flowering stage affect rice yield. Hence, it is very

important to understand the thermal changes of rice canopy during drought and heat stress conditions. Thus, objective of this study was to assess the thermal changes inside the canopy and its impact on pollen fertility and yield. A split plot design with three replicates was used for the field experiments at Field Crops Research and Development Institute, Mahailluppallama in three Yala seasons from Yala 2014 to Yala 2016. Main factor was the planting time (early and late planting) which synchronizes flowering at different temperature regimes. Sub-plots were Bg 358 flooded, Bg 358 drought stress, Bg 366 flooded and Bg 366 drought stress. Data were collected on ambient temperature, relative humidity, canopy temperature, volumetric moisture content of soil, pollen fertility and grain yield. The lowest canopy temperature was observed in early planting flood treatments. Maintaining volumetric moisture content at 27.5% with a canopy temperature of 30 oC resulted in 90% pollen fertility. Peak canopy temperature and canopy temperature at flower opening was highly correlated with grain yield. Peak canopy temperature and canopy temperature at 10:00 am augmented the rice yield. The critical canopy temperature on yield was estimated as 34.0 oC. Maintenance of standing water at flowering stage is an important migratory option to avoid heat stress rice.

Key words: Canopy temperature, Moisture stress, Planting time, Pollen fertility.



Evaluation of management strategies of Tuta absoluta (Lepidoptera: Gelechiidae) in tomato

T.K.A.I. Hadji1, K.P. Somachandra1, S.S. Weligamage2, K.M.D.W.P. Nishantha2, N.S. Senanayake1, K.D.M. Kularathne1, H.G.C.W. Gamage1, A. Dharmasena1,

J.P. Marasinghe3 and S.D.K. Priyadarshani4

1Regional Agriculture Research and Development Centre, Bandarawela, Sri Lanka2Horticulture Crops Research and Development Institute, Peradeniya, Sri Lanka

3Registrar of Pesticides Office, Getambe, Sri Lanka

AbstractTomato leaf and fruit miner, Tuta absoluta is a very destructive pest of tomato

and other solanaceae plants in the world. This pest is problematic in both open fields and greenhouses and can cause 80% to 100% yield loss, if not properly managed. It was first reported in Sri Lanka during July 2017 on tomato in some poly-tunnels in Badulla district and later spread to many other areas in the country. As the pest is new to the country, no recommended insecticides or control measures were available at that time. Therefore, a series of studies were carried out in poly-tunnels and in open fields for five consecutive seasons starting from Yala 2017 to identify appropriate management strategies to control larvae and trapping methods to monitor and control of adults. Eleven insecticides were tested in poly-tunnels and four insecticides viz., Spinetoram 25% WG (2.5 g/10 l), Emamectin Bbenzoate 5% SG (4 g/10 l), Indoxacarb 150 g/l EC (4 ml/10 l) and Abamectin 18 g/l EC (6 ml/10 l) were selected for further studies based on larval mortality recorded 24 hrs after application. Simultaneously, eight different traps including light, sticky, insecticidal and pheromonal were evaluated for mass trapping of T. absoluta adults in greenhouses. Results have revealed that selected chemicals were effective in managing T. absoluta larvae in greenhouse tomato whereas only Spinetoram 25% WG (2.5 g/10 l) was effective in open fields. CFL light traps were suitable for mass trapping of T. absoluta adults in greenhouses. Pheromone traps can be used to monitor adult population.

Key words: Insecticides, Light traps, Pheromones, Tomato, Tuta absoluta



Influence of plant growth regulators and foliar nutrients on growth and yield of chilli

H.M.P.T.K. Hettigedara and G.H.K. de Silva

Field Crops Research and Development Institute, Mahailluppallama, Sri Lanka

AbstractApplication of growth promoters and stimulants containing plant growth

regulators is a common practice among chilli farmers. An experiment was conducted in Yala 2017 and Maha 2017/18 seasons to identify the influence of analytical grade plant growth regulators Gibberellic Acid (GA3), Naphthalene Acetic Acid (NAA) and one commercial product containing of 10% GA3, 6% Ca and 2% B and followed by Albert solution as a foliar nutrient spray on growth and yield of chilli variety MICH hy 1. The experiment consisted of two factors, (i) application of different plant growth regulators ((T1) - 50 ppm GA3, (T2 ) - 100 ppm GA3, (T3) - 50 ppm commercial product, (T4) - 100 ppm commercial product, (T5 ) - 50 ppm NAA, (T6) - control - spray distilled water and two levels of Albert solution, namely, application of the Albert solution and without Albert solution. The treatments were applied at the flower initiation stage. Three days after the application of plant growth regulator, the Albert solution was applied and another dose of Albert solution was applied 20 days later. Application of GA3 and the commercial product significantly increased the plant height and canopy width while it reduced the SPAD meter value which is an indication of the chlorophyll content. Application of plant growth regulators did not influence the green chilli yield.

Key words: Albert solution, Chilli, Foliar spray Gibberellic Acid, Naphthalene, Acetic Acid



Weed dominance and status of herbicide resistance in Ischaemum rugosum in direct seeded rice in the Dry zone

H.M.S. Herath1, R.F. Hafeel1, N.P. Manamperi1, R.M.U.S. Bandara2,B. Marambe3 and V.R. Kumar4

1Rice Research Station, Ambalantota, Sri Lanka2Rice Research and Development Institute, Batalagoda, Sri Lanka

3Department of Crop Science, Faculty of Agriculture, University of Peradeniya,Sri Lanka

4International Rice Research Institute, Los Baños, The Philippines

AbstractWeed species dominance significantly contributes to yield losses in Direct

Seeded Rice (DSR) production systems. This study aimed at determining the dominance nature of weeds and development of herbicides resistance in I. rugosum populations found in paddy fields. Studies were carried out in 40 farmer fields in Hambantota district of Sri Lanka during Maha 2017/2018 (Major growing season; October to February) and Yala 2018 (Minor growing season; March-September) using 5 m2 sampling size per field. Data were collected from each site at eight weeks after crop establishment. The contribution of each weed species to the weed community in paddy fields was determined using the relative weed density and relative dry weight. Dose responses experiments were conducted using I. rugosum against the pre-mixed herbicide formulations; Bispyribac sodium 40 g/1 + Metamifop 100 g/l SC, Clomazone 200 g + Propanil 400 g/l and Thiobencarb 400 g/l +Propanil 200 g/l EC. Results showed that the C4 grasses dominated the paddy fields in both seasons, and they were more competitive in the relatively dry Yala season compared to that of wet Maha season. The C4 grasses E. crus-galli and I. rugosum were the dominant weeds in Maha 2017/18 and Yala 2018 season, respectively. Three I. rugosum populations exhibited possible multiple resistance development to the pre-mix herbicide formulation. Bispyribac sodium 40 g/1 + Metamifop 100 g/1 SC, containing herbicides with two different modes of action (ALS-inhibitor and ACCase inhibitor, respectively), showing a resistance index (RI) of 1.8, 2.8 and 1.68. Continuous use of herbicide influence the level of dominance of weed species in DSR and hence, weed management practices in the paddy fields of Dry zone should be implemented based on the nature of weed dominance.

Key words: Herbicide resistance, Ischaemum rugosum, Weed dynamics



Consumer willingness to pay for commodities certified under Sri Lanka Good Agriculture Practices (SL-GAP)

A.S.M. Roshan1 and M. Burton2

1Division of Agribusiness Counseling, Extension & Training Centre, Sri Lanka 2School of Agriculture and Environment, University of Western Australia

AbstractConsumers in developing countries are increasingly concerned about the safety

of the food that they consume resulting increased demand for safe foods. Agricultural supply chain, thus, need to be ready to cater to this growing demand. Estimates on consumer willingness to pay for safe food attributes are vital for policy makers to set up feasible food safety standards. This paper aims to evaluate how Sri Lankan urban consumers are concerned with the products certified under Sri Lanka Good Agriculture Practices (SL-GAP), which is a government-backed food safety management standard. A double bounded Contingent Valuation (CV) survey approach was employed to estimate the consumer willingness to pay for SL-GAP certified rice and tomato. Data was gathered from a survey carried out among 366 consumers in five urban districts in Sri Lanka for the estimation. The model for rice and tomato were jointly estimated using a multivariate probit model, which allowed error terms within and across commodities to be correlated. The estimated median values of willingness to pay for SL-GAP rice and tomato was 41.9% and 39.1% premium, respectively. The premium percentages further increased with prior consumer experience with products certified as organic.

Key words: Contingent valuation, Food safety, Good Agriculture Practices (GAP)



Assessment of technical efficiency of maize production in Sri Lanka

J.K. Galabada, W.M.U. Palipana and W.M.S.K. Weerasinghe

Socio Economics and Planning Centre, Department of Agriculture, Peradeniya, Sri Lanka

AbstractMaize, being a primary ingredient for food and feed industry, is a vital cereal

crop in Sri Lanka. The escalating demand for poultry feed and pre-cooked processed cereal items have significantly increased the demand for local maize production over the last several years and thus, productivity enhancement of local maize producers is an urgent and timely need. This study examines the degree of technical efficiency of maize production in Sri Lanka and its determinants using a stochastic frontier production function. The production function was specified treating maize yield as the dependent variable and seed, fertilizer, agro-chemical, machinery and labor as the independent variables. An inefficiency model was specified to find out potential determinants of technical efficiency. Data for the estimation was gathered from a survey conducted in Anuradhapura, Monaragala and Ampara districts covering 60 farmers from each district. The results revealed that the mean technical efficiencies of maize production in Anuradhapura, Monaragala and Ampara are 59%, 64% and 65% respectively. The technical efficiency of an average maize farmer is 62% implying that there is a large potential to enhance maize production without incurring an additional cost. Primary occupation, education and experience are the major determinants of technical efficiency of maize production. Provision of targeted extension services, facilitation of knowledge and skills sharing between experienced farmers and bringing young farmers in to the maize value chain are recommended to increase the technical efficiency of maize production.

Key words: Maize production, Regional differences, Stochastic frontier analysis, Technical efficiency



Agronomic practices to enhance crop establishment, grain yield and weed suppression in flooded-direct seeded rice

T.K. Illangakoon1, B. Marambe2, R.S.K. Keerthisena1, A.P. Bentota1, C.H. Piyasiri1, J.M.N.P. Somarathne1, W.U.S. Geethika1 and V. Kumar3

1Rice Research and Development Institute, Batalagoda, Sri Lanka

2Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka

3International Rice Research Institute, Los Banos, Philippines

AbstractThe ability of rice to germinate and develop seedlings under water logged

conditions is defined as anaerobic germination tolerance of rice (AG-tolerance) and can be combined with direct seeded rice (flooded-DSR) to suppress weeds and to increase crop stand in flood prone rice growing areas. However, success of flooded-DSR depends on agronomic practices that are being carried out. Therefore, two experiments were conducted at the Rice Research and Development Institute, Batalagoda, Sri Lanka to evaluate flood water heights at sowing and seeding rate on crop establishment, panicle density and grain yield and weed biomass in flooded-DSR. In experiment 1 (Maha 2014/15 and Yala 2015), two water levels (5 cm, saturated) and three seeding rates (60, 80, 100 kgha-1) were evaluated. The experiment 2 was conducted in Maha 2015/16 and Maha 2016/17 to evaluate three water levels (5 cm, 2.5 cm, saturated), and three different seeding rates (100, 125, 150 kgha-1). In all experiments, crop establishment reduced substantially in 5 cm flooding compared to saturated condition. When weeds were controlled, panicle density and grain yield increased in saturated condition compared to 5 cm flooding while under no weed control, 2.5 cm flooding gave the highest panicle density and grain yield with reduction of weed growth by 31-58% compared to saturated condition. Seeding rates ≤ 80 kgha-1 reduced panicle density and grain yield under flooding. However, seeds sown >125 kgha-1 rates had no effect to increase panicle density or grain yield. Therefore, adjusting flood water height at 2.5 cm at sowing and using 100 kgha-1 seeding rate can optimize crop establishment, panicle density and grain yield with considerable reduction in grasses and sedges in flooded-DSR.

Key words: Anaerobic germination tolerance, Flooded-direct seeded rice, Seeding rate, Water height



Assessment of existing fertigation protocols in protected culture of vegetable crops in relation to marketable yield

H.R.U.T. Erabadupitiya1, J.K. Galabada2 and W.A.P. Weerakkody3

1Seed Certification Service, Department of Agriculture, Gannoruwa, Sri Lanka2Socio Economics and Planning Center, Department of Agriculture, Peradeniya,

Sri Lanka3Department of Crop Science, Faculty of Agriculture, University of Peradeniya,

Sri Lanka

Abstract Fertigation in soilless culture is a major determinant of the quality and quantity

of the greenhouse crop yields. Sri Lankan growers are facing several problems of using hydroponic fertilizers. Thus, the over use and misuse of fertilizer have become a common problem in protected culture with subsequent increase in cost of production. Hence, this survey was conducted to find out the demographic profile of the greenhouse growers, most effective fertilizer schedule and growing medium for main greenhouse crops. On-farm data collection was done to confirm the data on fertigation collected from the farmer survey. Different fertigation schedules and growing media were evaluated for marketable yield. The more suitable and effective fertigation schedule was selected for different growth stages in each crop. According to the results obtained, the lower level of fertigation schedules that produce significantly higher marketable yield were selected as the most effective fertilizer schedules. For salad cucumber, it was 0.5, 1, 1.2 g/plant/day of Albert’s fertilizer solution while for bell-pepper and tomato, it was 0.5, 1, 1.5 g/plant/day during 1-4, 5-8 and 9 week onwards after transplanting, respectively. Greenhouse growers in Sri Lanka used to apply different kind of growing media with different ratios of the composition. A significant yield difference could not be identified among different growing media used for hydroponic culture.

Key words: Albert’s solution, Coir medium, Hydroponic, Poly-tunnel, Soluble fertilizer, Vegetables.



Identification of the causal pathogen of bacterial wilt disease in cucurbitaceous crops and bean and its alternative weed hosts in

Sri Lanka

W.A.P.G. Weeraratne and D.M.K.K. Dissanayake

Horticultural Crop Research and Development Institute, Peradeniya, Sri Lanka

AbstractBacterial wilt caused by Ralstonia solanacearum is a destructive disease and

one of the major constraints in vegetable production of Sri Lanka. Outbreak of bacterial wilt disease occurred in recent years for the first time in cucurbits and bean cultivated fields with 50-100% disease incidence. Hence, the present study was carried out with the objectives of isolation and molecular identification of causal pathogen of bacterial wilt of cucurbits and beans and to identify the weed hosts that harbour the bacterial wilt pathogen. Based on morphological and PCR analysis, gene sequence and homology search results, the causal pathogen of bacterial wilt disease in Momordica charantia, Cucumis sativus, Luffa acutangula, Cucurbita maxima, Cucumis anguria, Citrullus lanatus and Phaseolus vulgaris in Sri Lanka were identified as R. solanacearum with 99.37-100% similarity with Gene bank Accession CP022795.1, CP025986.1 and MF373815.1 of R. solanacearum. Twenty five out of 28 weeds species collected from Bacterial wilt infected fields were identified as symptomless carriers of R. solanacearum. All eight isolates from cucurbits and bean and 25 weeds species belong to biovar 3 and race 3 of R. solanacearum. This is the first report of R. solanacearum causing bacterial wilt in cucurbits, bean and weeds in Sri Lanka.

Key words: Bacterial wilt, Bean, Cucurbits, Molecular Identification, Weeds



Spatial variation of soil properties in paddy fields of Polonnaruwa district

W.M.U.K. Rathnayake1, D.N. Sirisena1, K.A. Renuka2, S. de Silva1, A.M. Piumika1 and A.M.R.S. Atapattu1

1Rice Research and Development Institute, Batalagoda, Sri Lanka

2Field Crops Research and Development Institute, Mahailluppallama, Sri Lanka

AbstractIdentification of spatial variation of soil chemical properties in paddy

fields and adoption of remedial measures are needed to maintain a good soil health. It has been well accepted that thematic maps of soil properties can use to identify the variations and introduce soil test based fertilizer recommendations for optimum crop yield while conserving the environment. Therefore, this study was conducted to prepare thematic maps of soil parameters in Polonnaruwa district. Soil samples in depth of 0-15 cm were collected from 2.5 km by 2.5 km grids. Sampling points were demarcated by Global Positioning System (GPS). Collected soil samples were analyzed for available soil P by Olsen’s method, exchangeable-K by 1N NH4OAc (pH=7) extraction method, exchangeable Zn by EDTA extraction, soil pH by 1:2.5 (soil:water), electrical conductivity by 1:5 (soil:water) and soil organic carbon contents by Walkley-Black method. Tested values were mapped using ArcGIS 10.5 and legends were prepared based on the optimum and critical values of each parameters. Available soil phosphorous maps of Polonnaruwa district showed that 32% of land have optimum P content and 58% of them have excess of P. Soil exchangeable K is low (< 80 mg/ kg) as 98% of land area and only 2% of area is in the optimum K level. About 32% of the land has low Soil pH and soil salinity is not critical in 98% of paddy field in the district. About 82% of the area shows critical level of Zn (<1 mg/kg) and 98% of them show very low level of organic matter (< 3%). The land parcels where remedial measures should be applied can be easily identified through the prepared maps even without analyzing soil samples in each field at any time.

Key words: Rice, Soil chemical properties, Spatial variation, Polonnaruwa



Influence of staggered cultivation and weather parameters on the outbreak of rice yellow stem borer (Scirpophaga incertulas

Walker) in Polonnaruwa district of Sri Lanka

L.D. Galanihe1, D.M.O.K.B. Dissanayake1 , A.A.F. Rizvana2, E.D.M. Wimaladharma3 and R.A.N. Sanjeewani3

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka2Agrarian Service Centre, Pulasthigama, Sri Lanka3Agrarian Service Centre, Medirigiriya, Sri Lanka

AbstractAn outbreak of Rice Yellow Stem Borer (RYSB) - Scirpophaga incertulas.

Walker - was occurred in Polonnaruwa district of Sri Lanka during Yala 2018 season causing heavy yield losses. An early pest infestation was also observed in the same area during Maha 2018/19 season. Hence, this survey was conducted to investigate whether there is any relationship among weather factors, cultural practices and rice stem borer outbreak in Pollonnaruwa district in Yala 2018. Delayed planting, staggered cultivation, lack of awareness among the farmers on identification of the pest and its damage symptoms along with lack of knowledge on control measures and improper use of insecticides were identified as the major underlying cause for the problem. Continuous cultivation of rice varieties that are more vulnerable to the RYSB attack also contributed to the population build up. The climatic conditions prevailed during the season contributed to aggravate the damage by increasing the RYSB population leading to an outbreak of the pest population resulting heavy yield losses.

Key words: Rice yellow stem borer, Pest outbreak, Staggered cultivation, Weather parameters



Evaluation and characterization of locally developed maize inbred lines for agro-morphological traits in Sri Lanka

W.M.R. Kumari1, N.A.P.S.G. Upasantha1, D.M.J.K. Dissanayake1 and W.A.U. Priyadarshani2

1Field Crops Research and Development Institute, Mahailluppallama, Sri Lanka 2School of Agriculture, Pelwehera, Sri Lanka

AbstractHybrid maize is widely grown in Sri Lanka due to its higher yield potential

gained through the heterosis breeding. The evaluation and characterization of maize inbred lines is primarily essential for selecting inbred parents with desirable agro-morphological traits to develop new hybrids with higher hybrid vigor. A study was conducted to evaluate and characterize 44 locally developed maize inbred lines for 17 agro-morphological traits at Field Crops Research and Development Institute, Mahailluppallama. A higher coefficient of variation was observed in grain yield, grain weight per cob and number of tassel branches. Inbred lines were significantly different for all agro-morphological traits. Grain yield showed significant and positive correlation with ear length, number of seeds per row, plant height, height to upper most ear, leaf length and tassel length. The grain yield was negatively correlated with anthesis to silking interval and days to silking. The cluster analysis based on quantitative traits, grouped 38% inbred lines into large cluster (C-3), three similar size clusters (C-1, C-2, and C-4) and two inbred lines formed distinct cluster (C-5). The combination of lines from C-1 or C-2 with C-3 or C-4 can be used to develop single cross hybrids with higher hybrid vigor. The evaluated maize inbred lines, MI2008-35, MI2008-13 and MI2008-7 consisted of more than one desirable traits such as higher yield (4.0-4.6 t/ha), higher 100 grain weight (28 -34 g), higher seed number per row (30-32), low ASI (-2 – 2), longer ears (16 cm). The information on cluster analysis can be used to identify the male and female parents from different clusters to develop maize hybrids with higher heterosis effect.

Key words: Agro-morphological traits, Cluster analysis, Heterosis breeding, Hybrid vigor, Maize inbred lines



Study on possibility of enhancing germinability of “Veralu” (Elaeocarpus serratus L.) seeds by pre-treatments and

germination variability of different accessions

M.K. Thantirige, K.A.S.C. Kumarapperuma, M.A.R.L. Perera and U.N. de Silva

Fruit Crop Research and Development Institute Horana, Sri Lanka

AbstractVeralu (Elaeocarpus serratus L) known as Ceylon Olive is one of the popular

underutilized fruit in Sri Lanka. In year 2011, four superior Veralu varieties were recommended for cultivation. The major constraint in expansion of Veralu cultivation is low seed germinability and extended time period taking for germination. With the objectives of increasing efficiency of germination and studying the variation in germinability, a series of experiments were conducted at the Fruit Research and Development Institute, Horana during 2018-2019. Neither hot nor cold temperature scarification treatments was effective in increasing the germinability. Both cracked seeds and endocarp removed seeds inhibited germination suggesting that the non-exisence of seed coat lead to seed dormancy. However, seeds packed in sealed black colour polythene (300 gauge) and kept for 15 days stimulated germination giving 50% success after 115±6 days. Similarly, seeds embedded in sand substrate with 1% moisture content in sealed opaque polythene bag (150 gauge) enclosed in another black color bag (300 gauge) and sun dried for 8 hours promoted germination showing a success rate of 58% by 80 days of sun drying. When germination behavior of two different seed weight categories were evaluated, it was found that small seeds (0.5 g - 1.0 g mean/seed) germinated at faster rate achieving 50% success rate by 68±2 days whereas for large seeds (1.0 g - 1.5 g mean/seed), number of days taken for 50% germination was 110±10 days. One of the important finding of the study is identification of two accessions having short dormancy periods of 52 days and 75 days in ACC 2 and ACC 5, respectively which can be recommended for cultivation without seed dormancy problem.

Key words: Seed dormancy, Elaeocarpus serratus L., (Ceylon Olive), Germinability, Pre-treatments



Adaptability of promising CIMMYT maize hybrids across diverse maize growing environments in Sri Lanka

W.M.R. Kumari1, D.C.S.M.I. Wijewardhana1, N.A.P.S.G. Upasantha1, W.M.N.D. Gunathilake2, T. Karunainathan3, W.M.W. Weerakoon4 and B.S. Vivek5

1Field Crops Research and Development Institute, Mahailluppallama, Department of Agriculture, Sri Lanka,

2Grain Legumes and Oil Crops Research and Development Institute, Angunakolapalasse, Sri Lanka.

3Agriculture Research Station, Thirunevelli, Sri Lanka 4Department of Agriculture, Sri Lanka

5CIMMYT, India, c/o ICRISAT, Patancheru, Hyderabad, India

AbstractMaize is the most important cereal crop mainly grown as a rainfed upland

crop in the Dry zone of Sri Lanka. Introduction of CIMMYT maize hybrids to local farmers can increase the availability of varieties with high yield potential and enhanced nutritional quality and environmental adaptability. Hence, introducing drought tolerant maize hybrids is vital for maize based cropping systems where unexpected intermittent drought is experienced even in rainy seasons. Testing adaptability and stability of CIMMYT drought tolerant single cross maize hybrids and selection of promising hybrids were carried out in multi-environmental trials conducted in maize growing areas in 2016, 2017 and 2018. A method where grain yield deviation of each variety from environmental mean in each environment was calculated to test adaptability and stability of varieties across environments. The maize hybrids, namely, VH112926, VH12264 and VH12263 were finally selected as the most adaptable and stable hybrids over diverse environments where they recorded an average yield of 5.81 to 5.95 t/ha with desirable ear characteristics. The selected hybrids showed 0-3 days of anthesis-silking interval, uniform ears, uniform color, better grain filling and good husk cover which are of highly concerned by maize farmers in Sri Lanka.

Key words: Adaptability and stability, Drought tolerant, Maize hybrids, Sri Lanka.



Tomato powder as a substitute for preserved tomato pulp in sauce production

D.N. Hettiarachchi1, H.M.P.B. Somarathne2, W.A.J.P. Wijesinghe2, D.L.C.N. Hitigedara1, R.A. Wijerathna1, H.R.P. Fernando1 and

S.M.A.C.U. Senarathne1

1Food Research Unit, Department of Agriculture, Gannoruwa, Sri Lanka2Faculty of Animal Science and Export Agriculture, Uva Wellassa University,

Badulla, Sri Lanka

AbstractTomato sauce of Sri Lanka is generally produced by using imported Preserved

Tomato Pulp (PTP) as raw materials due to very high seasonality of the crop. This problem can be overcome by producing powdered tomato locally to substitute PTP in tomato sauce manufacturing industry in Sri Lanka. Hence, this study was conducted to investigate the feasibility of producing tomato powder from fresh tomato fruits. Tomato fruits were dehydrated with seed (S+) and without seed (S-) in vacuum (V) and conventional (C) resulting four combinations of powder samples, namely, VS+, VS-, CS+ and CS- along with a control of fresh pulp. Powdered tomato were stored in glass bottles for six months. Physicochemical, phytochemical and sensory properties of powdered samples were analyzed at the end of every month during the study period. Nutrient retention was relatively higher in both VS+ and VS- samples than that of CS+ and CS- in both powdered and sauce samples. No significant differences were observed in physicochemical properties of sauce prepared using VS+ and control (p<0.05). Vacuum dried tomato powder made out of fresh tomato fruits with seeds can effectively be used as a raw material in tomato sauce industry in Sri Lanka.

Key words: Preserved tomato pulp, Powdered tomato, Vacuum dehydration, Tomato sauce

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Management of chilli root knot nematodes (Meloidogyne spp.) in Sri Lanka

S. Rajeshkanna1, K. Holmes2 and S. Toepfer2

1Regional Agriculture Research and Development Centre, Department of Agriculture, Kilinochchi, Sri Lanka

2CABI in Delémont, Canton of Jura, Switzerland

AbstractChilli is an important profitable cash crop cultivated mainly in the Dry zone

(annual rainfall less than 1000 mm) of Sri Lanka. During the recent past, an outbreak of root knot nematode (Meloidogyne spp.) in chilli (CRKN) was observed causing extensive damages to chilli production in Sri Lanka. Therefore, introduction of user and eco-friendly management method for the CRKN has become a main challenge in Sri Lanka. A series of experimental findings were collected from different sources related to RKN. The Integrated Pest Management (IPM) principles of International Organization for Biological Control (IOBC) were used with some adjustment to fit into country policies and availability of resources to be used to develop the IPM package for CRKN. That includes prevention, monitoring, non-chemical and chemical control methods and restrictions. The package also suggested ways to improve soil biodiversity as how to implement the package by incorporating capacity building for farmers and extension officers in chilli cultivation. In addition, the study has suggested ways in which the package can be implemented and incorporated in capacity building for farmers and extension officers and it will create interest on younger generation to involve in farming activities. The successful implementation of IPM package for CRKN will require farmers’ adaptations, through involvement of scientists, experts on farmer field school and efficient extension system with adequate funding supports.

Key words: Integrated Pest Management, Meladogyne

IntroductionChilli is one of the major cash crops grown in Sri Lanka. Both green and dry

chilli are used as condiments for Sri Lankan meals. The dry chilli annual per capita consumption is around 2.84 kg. The national requirement per year is around 57,400 mt (DOA, 2018). The current annual production of dry chilli is about 7,500 mt, in Sri Lanka. Thus, the balance (49,900 mt) is imported from other countries. The

Annals of Sri Lanka Department of Agriculture 2019. 21

** Review Article

28 Rajeshkanna et al.

contribution of chilli to GDP is approximately Rs. 5,000 mn and it provides employment to the local people.

A survey of plant parasitic nematodes carried out in Sri Lanka indicates that root-knot nematodes Meloidogyne spp., are major pests of various staple food, vegetable, fruit and ornamental crops (Ekanayake, 1981). Premachchandra et al. (2007) conducted a survey in vegetable growing regions of Matara District in Sri Lanka regarding infestations of root-knot nematodes by Meloidogyne spp. They identified two Meloidogyne spp. namely Meloidogyne incognita and Meloidogyne javanica in chilli crop. Accordance with Plantwise Online Management System (POMS) data analysed in 2018, CRKN was reported in different areas of the country such as, Mannar, Vavuniya, Kilinochchi, Galle, Anuradhapura, Ampara, Batticaloa, Galle and Colombo districts. In addition to this, chilli growing farmers from various parts of Sri Lanka reported CRKN problems to the HORDI, Gannoruwa.

At present there is no effective and consumer safe nematicide available in Sri Lanka. Therefore, farmers are unable to manage the CRKN in nematode prone areas. Furthermore, farmers are not well aware of the non-chemical management method for root knot nematodes in vegetable crop cultivation.

Currently, Sri Lanka has a severe problem with CRKN and there is a need for an effective IPM package against CRKN. The proposed IPM package has been developed based on knowledge from various sources and field experience working with chilli growing farmers in Sri Lanka. This IPM technical package should be implemented by all chilli farmers following training by extension officers in Sri Lanka, under the direct supervision of Department of Agriculture.

An IPM package is a set of key tools which can be used by farmers to enable them to sustainably manage chilli root knot nematode and it provides a holistic management approach to be implemented by chilli growers in Sri Lanka. It will trigger sound research concepts for researchers who have been working on root knot nematodes in various crops and improve the capacity of extension officers. This document presents technical guidance for the management of CRKN and highlights the potential mechanism for its adoption in Sri Lanka.

Management of chilli root knot nematodeThe most successful approach to nematode control rely on integrated pest

management strategies (IPM) and main objective of IPM is to maintain nematode

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population below economic threshold level (ETL). Combinations of IPM tactics, include cultural practices, physical and mechanical controls, biological and chemical measures (Mitkowaski and Abavi, 2003).

The aim of IPM as a strategic approach in the direction of crop protection is to promote the quality and quantity of the agricultural production while reducing the impact of pesticide use on the environment and human well-being. In designing an IPM strategy package following five basic principles have been adopted under the IOBC guideline (Wijnands et al., 2012); prevention, monitoring, non-chemical control methods, chemical control methods and restriction of chemical controls.

1.0 PreventionUnder the prevention, the severity of many pests and disease incidences can

be significantly reduced by applying agronomic practices that favour the crops against their damaging organisms (Wijnands et al., 2012).

1.1 Conservation of soil biodiversitySoil contains many antagonistic organisms that affect negatively on populations

of plant parasitic nematodes inhabiting soil. Therefore, understanding methods to enhance the antagonistic populations through soil amendments and other biological and physical methods would help to reduce plant parasitic nematode populations. To enhance the populations of antagonist for nematodes, farmers should consider the following farm practices (Timper, 2014); Increases the fallowing period to develop the antagonistic fungus such as Arthrobotrys dactyloides, Dactylaria brochopaga, Monacrosporium ellipsosporum and Metarhizium gephyropagum, which are among species with restricted saprophytic capability, are consistently associated closely with plant roots and thus in a favourable position to prey upon plant pathogenic nematodes (Mankau, 1980). In addition, minimum or zero tillage enhances the antagonistic fungus in soil. Also adding organic amendments (see 1.2) increase the population of soil antagonist for nematodes, crop rotation sequences - Crotalaria use as an intercrop with chilli will allow the nematode-antagonistic microorganisms (Wang, 2000).

1.2 Site selectionFarmers should have a clear idea of avoiding nematode problems in choosing

a new cultivation area. At a more local level, the planting site should be chosen after considering the known distribution of nematodes on the farm resulting from varying environmental conditions, and the cultural and cropping history of each field. Accurate


diagnosis of CRKN infestations usually requires laboratory analysis for detection and identification. The Department of Agriculture provides the facilities for farmers to do laboratory analysis through extension officers (Plant doctors) with free of charge.

The following steps will help to get a good sample (Olsen et al., 2013).

Soil samples should be taken near actively growing roots and sample should be collected when soils are warm and moist, because nematodes are most active in warm, moist soils.Take more samples from the field of interest. Mix all samples well and place in a plastic bag. Label the bag with location host plant, date and collector name and do not add water and protect the sample bags from extreme temperature. Do not allow the samples to dry out. If necessary, samples can be stored at room temperature for up to a week.

1.3 Field sanitationThe root knot nematodes are commonly introduced into the un-infested

fields through infested soil or seedlings. The chilli seedlings must be purchased from nematode-free nurseries such as Government farms in each district. For maintaining the plant sanitation the following aspects should be strictly adopted by the farmers (Perry and Ploeg, 2010);

The chilli seedling nurseries should be registered and free from nematodes and need to be closely monitored and certified by the plant protection service.

Before planting roots of seedlings should be inspected and ensure free from galls, if galls are found in roots avoid planting such seedlings.

Avoid moving plants and soil from infested parts of the garden, to prevent the spread of nematodes.

Apply farm yard manure after composting well to ensure the soil is free from CRKN.

Nematodes can be present in soil attached to tools and equipment used elsewhere. Therefore, clean the machinery and tools by clean and hot water after working in nematode-infested fields.

Pull out the infected plant and burn it. Since nematodes reproduce on certain weed species, weed control can significantly help minimize population growth.

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1.4 Crop residue managementNematode infected plants and roots need to be eradicated to prevent nematodes

from multiplying after harvest. Therefore, farmers must uproot the chilli plants after harvesting and expose the roots to solar radiation or burn them (Barker and Koenning,1998). Incorporate the crop residues of marigold, mustard and sunflower after harvesting into soil to suppress the root knot nematodes before chilli cultivation (Akhtar and Alam, 1990).

1.5 Removing of alternative weed hostsWithout a strong weed management program, the benefits of crop rotation for

nematode management could be invalid due to weed hosts of plant-parasitic nematodes. All the host weeds should be free in the agricultural fields (Table 1).

Table 1. Alternative weed hosts for root knot nematodesNo Scientific name Common name Source of references1 Cyperus esculentus Yellow nutsedge Barlow, 20112 Cyperus rotundus Purple nutsedge Barlow, 20113 Acalyphaindica Indian Nettle Pakeerathan et al., 20094 Momordica charantia Wild bitter gourd Singh et al., 20105 Coccinia grandis Ivy gourd Singh et al., 20106 Cyanthillium cinereum Vernonia Singh et al., 20107 Ageratum conyzoides Tropical white weed Singh et al., 20108 Solanum nigrum Black nightshade Gharabadiyan et al., 20129 Datura stramonium Jimson weed Gharabadiyan et al., 201210 Echinochla crus-galli Barnyard grass Gharabadiyan et al., 201211 Portulaca oleracea Common purslane Gharabadiyan et al., 2012

Recommendations of plants for crop rotation to farmers include clear statements about the necessity of controlling weeds, particularly in between the cropping cycles (Rich et al., 2008).

1.6 Disinfection of planting materialsThe planting materials of chilli treated with neem (Azadiracta indica) and

pongam (Pongamia pinnata) oil at 0.2% concentrations reduced knot formation in the roots (Sivakumar and Gunasegaran, 2011). The treatments are as follow: Before seeding, the chilli seeds treat with the neem oil product at 0.2% concentrations and allow to shade dry for 48 hours and before transplanting, the root portions of 25-day old seedlings immerse in the neem or pongam oil at 0.2% concentrations for 30 minutes.


1.7 Crop rotationBy the crop rotation, nematode numbers are reduced simply because nematodes

are deprived of a suitable host crop. This does not mean that nematode densities are reduced indefinitely, but a successful crop rotation should reduce nematode levels enough so that a following susceptible crop will produce sufficient yields and survive until the end of its regular growing season (McSorley, 1996). Rotation with non-host crops provide excellent control of root-knot nematodes. Suggested rotation crops are given below (Table 2).

Table 2. Non-host crops for annual rotation with chilli crop to manage root knot nematodes

No Common name Scientific name Source1 Pearl millet Sorghum bicolar McSorley, 19962 Cowpea Vigna unguiculate McSorley, 19963 Marigold Tagetes spp. McSorley, 19964 Rice Oryza sativum Singh and Prasad, 20165 Mustard Brassica nigra Singh and Prasad, 20166 Gingelly Sesamum spp. Singh and Prasad, 20167 Onion Allium cepa Singh and Prasad, 20168 Garlic Allium sativum Singh and Prasad, 20169 Maize Zea maize Singh and Prasad, 201610 Leeks Allium ampeloprasum Singh and Prasad, 201611 Sun hemp Crotalaria juncea Wang et al., 2002

1.8 IrrigationThe control of nematodes in irrigation water should be important and form an

integrated part of any IPM system.

Apply nematicide and bio agents using drip irrigation system because it is simple, safe and more cost effective than conventional methods (Ramakrishnan et al., 2010). Chilli growers should avoid use of pond water for irrigation or spray mixtures because nematodes can be carried in irrigation water that has drained from an infested field (Noling, 1999).

Irrigate more frequently and it will reduce nematode damage. If the field has many nematodes in the soil due to the water stress will result more damaged plants. Increase the soil water holding capacity by adding organic matter to in sandy soil to reduce the effects of nematode injury (Perry and Ploeg, 2010).

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1.9 Plant nutrition managementNutrient management is very important in chilli cultivation to enhance the plant

growth and health that helps to improve the plant immunity and resistance against the plant pathogens. The soil testing must be compulsory to determine the plant nutrients in soil prior to application of fertilizers.

Farmers who need soil testing can approach extension officers in each AI range. The report of soil test provides information on; N, P and K content of soil, soil pH, EC, organic matter and fertilizer recommendations, etc.

Advise farmers to apply urea fertilizers with molasses or paddy straw as a nematicide at the rate of 300 kg N per hectare (Huebner et al., 1983).

Make phosphate available in soil by adjusting the pH value and it enhances secretion of root exudates which results roots becoming less attractive to nematodes and leading to low infestation and build plant resistance to nematodes (Marschner, 1997).

When calcium deficiency occurs in soil, supply calcium carbide to supress the nematodes and increase the crop yield (Mohamed and Youssef, 2009).

Supply of silicate medium to the plant through soil application results greatest decrease of Meloidogyne spp. (Silva et al., 2010).

Maintain Zn mineral at a sufficient level in the soil for decreasing the number of nematodes and increasing antagonistic activity of rhizobacteria (Shaukat and Siddiqui, 2003).

Maintain the organic materials with C: N ratio less than 20:1 to have higher degradation rate of organic manure and provide nematicide activities (McSorley and Gallaher, 1995).

Incorporate cattle manure to the soil during land preparation and it will result in significant reductions of numbers of nematode root galls and egg masses (Ibrahim et al., 2007).

Apply poultry manure at the rate of 18 mt/ha (Stevens et al., 2003) or goat manure will be the best alternative in the management of M. incognita (Pakeerathan et al., 2009)


1.10 Soil Amendments Organic amendments have been demonstrated to be effective against nematodes

and enhance or prolong the effect of nematicide (Muller and Gooch, 1982).

Apply finely ground neem cake at the rate of 30 g per plant or 40 g/kg of soil at 03 weeks before transplanting in the nematode infested field (Bhattacharya and Goswami, 1987; Raveendra et al., 2011).

Incorporate well powdered chitin waste materials (crabs shell and shrimps skin) at the rate of 0.4 to 0.8% (w/W) with soil at 10 weeks before planting (Godoy, 1983).

Apply oyster or button mushroom compost with the concentration of 1:1 ratio with potting medium to suppress root-knot nematodes (Aslam and Saifullah, 2013).

2.0 Monitoring Regular observation need from seedlings stage to mature plants for the

characteristic symptoms of root knot nematodes in both above ground and below ground. Observe foliar symptoms as follows (Moens et al., 2009).

Premature wilting within field as patches and leaf yellowing, early flowering and fruiting, plant shows stunting growth, uproot the plant wash with water and observe the gall like structures in the roots.

Infestation level of nematodes in soil can be monitored by analysing soil samples directly by counting eggs and juveniles or by indexing of gall formation in the crop. Otherwise, plant the few number of susceptible crops within the fields and can be examined directly in the field for the presence of galls such as; okra, and tomatoes and highest infections on roots and in soil will be found close to harvest (Widmer et al., 2018).

3.0 Non-chemical control methodsNon-chemical control measures can be substitute chemical pesticides in

some extent and optimize interferences with pest and diseases resulted less harm for environment and human health (Wijnands et al., 2012).

3.1. Solarization of nursery bedsSolarization is suitable for clay or sandy soil before seeding the nursery beds.

Cover desired area with clear plastic for a period of 4-8 weeks under the direct sunlight. Allow heat to penetrate deeply enough to kill and reduce nematode populations (Seebold, 2014).

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3.2. Hot water treatment of soilThis is both highly effective and may be the only practical control option

available to growers. Nematodes are killed by exposure to 40-54 oC depending on the species. Any method that will thoroughly heat soil and plant residues above the temperatures will kill nematodes (RPD, 1993).The following steps will be done in the hot water treatment;

Moist soil with hot water using porous based container with the temperature of 82 0C and cover the soil with plastic sheet for 30 minutes to kill all nematodes residing in soil.

3.3. BurningSterilize the nursery soil by burning, using locally available materials is a cost-

effective method prior to seeding. The DOA (2018) highly recommended this method to sterilize the nursery beds for all vegetable crops. In this method, the following steps will be done.

Wet the soil adequately and put a straw layer of about 3-5 cm height and a paddy husk layer on it. Place the paddy husk and paddy straw up to 4 layers alternatively and switch the fire opposite the wind direction and allow the soil to cool for 2 to 3 days.

3.4. Bio fumigationPlant materials used as bio fumigants against root knot nematodes results in

more effective and sustainable control in comparison with chemicals. Select the plant materials with availability in the cultivation area.

Apply following plant materials Morning glory (Ipomoea fistulosa) or Congress weed (Parthenium hysterophorus) or Neem (Azadirachta indica) or Giant milk weed (Calotropis procera) at the rate of 40 mt per hectare (4 kg/m2), 15 days before soil solarisation to suppress the root knot nematodes in soil (Patel et al., 2006). Use of crucifer vegetable leaf wastes (cabbage, radish, etc. ) on the soil surface at the rate of 1 kg per 5 kg of soil and cover the soil with polyethylene sheet for 15 days (Anita, 2012).

3.5. Novel fumigationThis method is most suitable for sterilizing nursery bed before seeding. During

soil fumigation the following steps were recommended by Su et al. (2015);

Prepare the nursery bed and loose the soil then measure the area and calculate quantity of soil up to root depth (25 cm). Apply at the rate of 0.428 kg of ammonium


bicarbonate and 0.857 kg of lime mixture for 1000 kg of soil. Keep soil moisture under 20% (gravimetric) for 15 days with sealed conditions using plastic sheet.

3.6. Plant extractUse of plant materials to manage root knot nematode is cost effective and

environmental friendly. Even though it needs more research works to find the efficacy and compatibility for chilli plant, the recommended plant materials are available in Sri Lanka to use directly by farmers.

Incorporate the grounded neem seed at the rate of 250 kg per 1000 m2 (1000 plants) to the soil 15 days before planting to control the root knot nematodes (Motha et al., 2010).

Spray basil leaves extract early in the morning to the chilli plant. Preparation of extract as follow; grind 50 g of basil leaves (Ocimum tenuiflorum) well and soak overnight in 2-3 l of water and strain the extract a cloth and add little soap to the extract then stir well (Sridhar et al., 2002). Soil drench with Moringa leaf powder into the infected field at the rate of 800 g/ 10 l of water to decrease the population of root knot nematodes (Sowley et al., 2014).

3.7 Biological controlThe products based on fungi and bacteria are being developed in some private

institutions (Green visva -Jaffna). However, such products are likely to be less effective than chemicals due to the poor formulations (Nirosha et al., 2017). Therefore, research intervention highly required to analyse the bio efficacy and rate of applications, mass production and local adaptations of biocontrol agents available in the country and importations

Farmers in Sri Lanka commonly practice application of Trichoderma spp. for vegetable crops without recommended dosage against some soil borne fungal pathogens such as onion bulb rot, collar rot in chilli, etc. But application of Trichoderma harzianum as reduced the number of nematodes in both soil and roots and it arrests the juveniles (Jindapunnapat et al., 2013). Add organic matter in agricultural soil to enhance and increase the activities and populations of nematode predators such as; collembola, tardigrades, and predatory mites generally in soils (Wang and McSorley, 2005).

Apply oilcake-based Trichoderma viride formulations into soil to manage the Meloidogyne incognita and increases chilli plant growth and yield (Nirosha et al., 2017).

37

4.0 Chemical control methodsIn Sri Lanka historically, root knot nematodes in all agriculture crops have

largely been controlled with nematicide. However, options for chemical control have been markedly reduced in recent years. The soil fumigant methyl bromide was banned twenty years ago and carbofuran was only available until 2014. The DOA has carried out a few trials and only identified Abamectin 20 SC which can be used for root knot nematode control and recommended to Registrar of Pesticides. This is a contact nematicide and apply diluted volume of 50 ml per seedling at planting point immediately before transplanting at the rate of 2500-3750 ml of active ingredient per hectare (400 ml/1000 plants). Before application, soil should be moistened sufficiently to ensure uniform application and distribution. This can be applied up to maximum of 4 times whithin a season (Syngenta Australia, 2018).

5.0 RestrictionsIn the nematode management, application of soil fumigants is entirely restricted

and soil application of fungicides also limited because they will affect the population of nematode - antagonist fungus in the soil. Normally in IPM, usage of herbicides avoided to conserve the natural enemies around the field but host weeds control very essential in nematode management.

ConclusionChilli is an important cash crop for farmers in the Dry zone of Sri Lanka.

However, during last few years, chilli farmers have been severely affected by root knot nematodes due to unavailability of effective nematicide and other non-chemical techniques. Instead of chemical control, IPM is the only way that is environmentally safe and sustainable management of CKRN can be imposed. The success of integrated nematode management will depend on many factors, such as; sound research, smart extension and training of farmers on IPM programme. Emphasis should be given on the integration of nematode management practices by adoption of sanitations, crop rotation, agronomic practices, application of organic amendments, biological control agents, and chemical control.

In future, there is a need to develop resistant chilli varieties against to root knot nematodes and collaborative breeding programmes should be intensified from other countries. Attempts should also be directed towards biological control. Especially fungus and bacteria have been identified all over the world as potential bio control agents against root knot nematodes in chilli. The developed IPM package for CRKN


is necessary to be practiced as a pilot programme in selected farmer fields. The implementation of this programme will require scientists, experts on FFS and efficient extension officers with adequate funding supports. In addition to these, they should also possess communication skills which are needed to work with the farmers.

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Ekanayake, K. 1981. Importance of plant parasitic nematodes in Sri Lanka and recommendations for control measures and future work, AGRIS Conference.

Gharabadiyan, F., S. Jamali, A.A. Yazdi, M.H. Hadizadeh and A. Eskandari. 2012. Weed hosts of root -knot nematodes in tomato fields, Journal of plant protection research. 52 (2).

Godoy, G., R. Rodriguez-Kabana and G. Morgan-Jones. 1983. Chitin amendments for control of Meloidogynearenaria in infested soil and effects on microbial population, Nematropica, 13: 63–74.

Huebner, R.A., R. Rodríguez-Kábana and R.M. Patterson. 1983. Hemicellulosic waste and urea for control plant parasitic nematodes, effect on soil enzyme activities, Nematropica. 13: 37-54.

Ibrahim, I.K.A., M.A.M. Saedy and A.A. Mokbel. 2007. Control of the root-knot nematode Meloidogyne incognita on sunflower plants with certain organic plant materials and biocontrol agents. Egypt. J. Phytopathol. 35(1): 13-24.

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Jindapunnapat, K., B. Chinnasri and S. Kwankuae. 2013. Biological control of root-knot nematodes (Meloidogyneenterolobii) in guava by the fungus Trichoderma harzianum, Journal of Developments in Sustainable Agriculture, 8 (2):110-118.

Mankau, R. 1980. Biocontrol fungi as nematode control agents, The Journal of nematology. 12 (4): 244- 252.

Marschner, H. 1997. Mineral nutrition of higher plants, London Academic Press. 889.

McSorley, R. and R.N. Gallaher. 1995. Effect of yard waste compost on plant-parasitic nematode densities in vegetable crops, Suppl. Journal of Nematol. 27: 545–549.

McSorley, R. 1996. Impact of management practices on soil nematode populations, Soil and Crop Sciences of Florida proceeding. 55: 63-66.

Mitkowaski, N.A. and G.S. Abavi. 2003. Root knot nematodes,The plant health instructor. DOI: https://www.apsnet.org (Accessed on 14.8.2018).

Moens, M., R.N. Perry and J.L. Starr. 2009. Meloidogyne species – a Diverse group of novel and important plant parasites. In: Perry, R.N., Moens, M. and Starr, J.L. (eds) Root-knot Nematodes. CAB International,Wallingford, UK. 1-17.

Mohamed, M.M. and M.M.A. Youssef. 2009. Efficacy of calcium carbide for managing Meloidogyne incognita infesting squash in Egypt. International Journal of. Nematol, 19: 229-231.

Motha, K.F., R. Abeysekara and N.S. Kottearachchi. 2010. Effect of biological agents and botanicals in controlling root-knot nematodes, Meloidogynespp in Nicotinatobacum, Tropical Agricultural Research & Extension. 1:13.

Muller, R. and P.S. Gooch. 1982, Nematological reviews: Organic amendments in nematode control. An examination of the literature. Nematropica. 12(2): 319-326.

Nirosha, A., S. Rajeshkanna and G. Mikunthan. 2017. Effect of oil cakes and garlic aqueous based formulations of Trichoderma viride on management of Meloidogyne incognita in chilli. Open Agriculture, 3(1): 214-219.

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Patel, S.K, H.V. Patel and A.D. Patel. 2006. Integrated management of root-knot nematode in tomato nursery through botanical plant materials. Indian Journal of Nematology. 36 (2): 307-308.

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Sowley, E.N.K., F. Kankam, J. Adomaka. 2014. Management of root-knot nematode (Meloidogyne spp.) on sweet pepper (Capsicum annuum L.) with moringa (Moringaoleifera Lam.) leaf powder,Archives of Phytopathology and Plant Protection. 47 :(13).

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Widmer, T.L., J.W. Ludwig and G.S. Abawi. 2018. The northern root-knot nematode on carrot, lettuce, and onion in New York, New York’s food and life sciences bulletin, Cornell University, NewYork: http://vegetablemdonline.ppath.cornell.edu/factsheets/rootknotnematode (Accessed on 23.09.2018).

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Effect of harvesting time on the seed yield and quality of common bean for seed production (Phasiolus vulgaris L.)

Y.L.B. Pavithrani1 and H.D. Fonseka2

1 Agriculture Research Station, Rahangala, Boralanda, Sri Lanka 2 Post Graduate Institute of Agriculture, Peradeniya, Sri Lanka

IntroductionBean (Phaseolus vulgaris L.) is an important leguminous crop growing

in Badulla, Kandy, Rathnapura and part of Nuwara Eliya district. According to the Department of Census and Statistics, Sri Lanka, annual bean production extent is 8,279 ha and annual production is 66,163 mt in year 2015.

Use of poor quality seeds, low soil fertility, adverse weather conditions and incidence of pests and diseases have been identified as some of the major constraints to bean production in the tropics (Wortmann and Allen, 1994; Gridley and Danial, 1995). While substantial research work has been done on breeding for improved varieties, response to soil fertility and pest and disease control and production of good quality seeds have not been sufficiently studied.

Seed development is the period between fertilization and accumulation of maximum of fresh weight, and the seed maturation begins at the end of seed development, which continues until harvest (Mehta et al., 1993). Seeds reach its maximum dry weight at physiological maturity and they should be harvested at that stage to ensure its quality in terms of germination and viability (Shaheb et al., 2015). Quality of bean seeds depends on many pre and post-harvest factors, like the area of production, cultivation techniques, seed maturity, methods of harvesting and threshing, processing and storage conditions.

To increase yield, use of quality seeds are essential for both vegetable and seed production. Seed maturity, viability and storability are important criteria correlated with each other (Shaheb et al., 2015). Early harvested seeds which are immature and poorly developed, resulting in poor quality that affects storability compared to seeds harvested at correct physiological maturity stage.

Delayed harvesting also results in the loss of yield due to shattering, damage of seeds and the risk of exposing to rain that affect quality of seeds. On the other hand, if seeds retained on plant after its physiological maturity, physiological changes in seed


** Short Communication

43

may result formation of hard seeds or off colored seeds in pulse crops (Shaheb et al., 2015).

According to Greven et al. (2004) time of harvesting is important due to reduce seed immaturity and rewetting which reduces seed quality. Kumar et al. (2002) reported that seed yield and quality largely depend on the stage of maturity of the crop. Therefore, harvesting seeds at optimum maturity stage is an essential requirement to maintain quality of seeds.

In Sri Lanka, time of harvesting is predicted by the change in color of the pods from green to yellow and finally to straw yellow. Bean harvesting starts when pods color have changed to straw yellow and may proceed until the pods are completely dry to the extent of shattering. The late harvest could lead to exposing the seed to deleterious conditions and enhance deterioration.

Local seed production sector suffered with low productivity under poor agronomic practices. The same agronomic practices have still being practised for both vegetable bean production and bean seed production. Therefore, Sri Lanka has to import large quantities of bean seeds to fulfill seed requirement of the country. According to DOA statistics, Sri Lanka has imported 128.5 mt of bean seeds in 2016.

Therefore the present study was conducted with the objective to identify appropriate harvesting time to maximize seed yield and to ensure quality of seed beans.

Materials and methodsThe trial was conducted at the research field of Agriculture Research Station,

Rahangala during Maha season from November 2017 to January 2018. The experimental site was located in IU3d Agro Ecological Region and having Red Yellow Podsolic soil.

The experimental treatments comprised of five different dates of harvesting viz., H1: 65 Days after emergence (DAE), H2: 70 DAE, H3: 75 DAE, H4: 80 DAE and H5: 85 DAE. The harvesting stages were characterized by deep green with light yellow color of pod (65 DAE), 50% green and 50% yellowing of pods (70 DAE), light brown with few yellow color pods (75 DAE), 90% brown color of pods (80 DAE) and 100% brown color and dried pods (85 DAE), respectively.

The Pole bean variety Bandarawela Green released by the Department of Agriculture was used for the experiment. The experiment was laid out according to Randomized Complete Block Design (RCBD) with four replications.

44 Pavithrani et al.

Planting bed size was 1-2 m with 50 cm ditches between beds and 200 g of dolomite was applied into each bed two weeks before planting. 2 kg of well decomposed cattle manure added to each bed five days before planting and incorporated well.

Urea, Triple Super Phosphate (TSP) and Muriate of Potash (MOP) were applied one day before planting at the rate of 110, 270 and 75 kg/ha respectively as the basal dressing recommended by the Department of Agriculture.

Seeds were then soaked in water overnight and treated with Thiamethoxam 70% WS over one hour before planting to control bean fly. Water soaked seeds were dibbed into planting holes with 70 x 20 cm spacing on well wetted beds. Irrigation was done at 2 days interval up to seedling emergence and thereafter 4 days interval until flower initiation. Approximately 100% field emergence was recorded at 10 days after sowing. At the flowering stage irrigation was done with 2 days interval up to 50 days (mid pod filling stage). Urea, and MOP applied at the rate of 110 and 75 kg/ha, respectively at 3 weeks after planting (WAP). Manual weeding was done at 2 WAP and 6 WAP.

Pods were harvested at different harvesting dates and number of pods per plant was counted with 10 randomly selected plants. Collected pods were sun dried until the moisture content reached up to 10-12%. Seed yield data collected from individual plots were calculated per hectare.

100 seed weight was obtained from two samples in each plot using well filled seeds with uniform seed size, shape and color and free from damages. Quality seeds were selected after drying when moisture content was 12%. Abnormal seeds that were damaged, deformed, diseased or discolored were discarded.

20 seeds from each plot were planted in pots and shoot length & root length of seedlings were measured at 7 days after emergence to calculate vigor index (Abdul-Baki and Anderson, 1973).

Vigour Index (VI) = (Mean root length (MRL)+Mean shoot length (MSL) x % germination (PG)

The data were statistically analyzed by using SAS system for Windows 9.0 and means were separated by using Duncan’s Multiple Range Test (DMRT) at 0.05 probability level.

45

Results and discussionHighest germination (98.7%), root length (6.3 cm) and shoot length (10.1 cm)

of seedlings and vigour index (1574.7) recorded from seeds harvested at 80 DAE (Table 1) while lowest germination (65.3%), root length (4.7 cm), shoot length (6.6 cm) and vigour index (738.7) were recorded from seeds harvested at 70 DAE (Table 1).

Seeds harvested at 80 DAE, 85 DAE and 90 DAE did not show a significant difference for % germination and vigour index of seedlings. Khatun et al. (2010) reported that early harvested seeds were immature and poorly developed compared to seeds harvested at physiological maturity. The present findings are in agreement with those findings while giving poor seed qualities in early harvested seeds (seeds harvested at 70 DAE).Table 1. Effect of time of harvesting on seed germination, root & shoot length and vigour index of seedlings

Germination % Root length (cm) 7 DAE

Shoot length (cm) 7 DAE

Vigour index

T1 (70 DAE) 65.33c±SE2.0 4.70b 6.6c 738.7b

T2 (75 DAE) 71.33b± SE2.0 4.73b 6.76c 819.93b

T3 (80 DAE) 98.66a± SE1.4 6.33a 10.13a 1574.67a

T4 (85 DAE) 96.66a± SE0.8 5.96a 9.13b 1459.40a

T5 (90 DAE) 95.66a± SE0.3 6.00a 8.9b 1470.47a

CV% 3.11 3.48 4.99 3.20R2 0.981 0.976 0.956 0.993

Note: means followed by the same letter are not significantly different, at p = 0.05

The highest total of seed yield was recorded for seeds harvested at 80 DAE (1.21 t/ha) and the lowest total seed yield was recorded from the seeds harvested at 70 DAE (Table 2).

100 seed weight was highest at seeds harvested at 80 DAE (25.8 g) with lowest value for seeds harvested at 70 DAE (24.3 g). 100 seed weight of seeds harvested at 80, 85 and 90 DAE did not show significant difference, but it showed gradual reduction in seed weight after 80 DAE.

According to Shaheb et al. (2015) seed reaches its maximum dry weight at physiological maturity and seeds should be harvested at this stage to ensure the quality in terms of germinability and vigour. According to the results of the present study, seeds harvested at 80 DAE showed maximum 100 seed weight (25.8 g), maximum %

46

Seed

yie

ld (t

/ha)

Qua

lity

seed

per

cent

age

Harvesting Stage (Days After Emergence)

Quality seed yieldTotal seed yieldQuality seed percentage

Pavithrani et al.

germination and vigour index. Therefore, 80 DAE can be considered as physiological maturity stage for common bean cultivate under Up Country Intermediate zone conditions. Table 2. Total seed yield, quality seed yield

Treatment Total seed yield (t/ha)

Quality seed yield (t/ha)

100 seed weight (g)

T1 (70 DAE) 0.66b 0.45b 24.27b

T2 (75 DAE) 0.80b 0.63b 24.43b

T3 (80 DAE) 1.21a 1.09a 25.80a

T4 (85 DAE) 1.16a 1.03a 25.47a

T5 (90 DAE) 1.14a 1.03a 25.23a

CV% 13.79 17.13 1.24Note: Means followed by the same letter are not significantly different, at p = 0.05

The marketable quality seeds yield (1.09 mt/ha) was highest at 80 DAE while lowest (4.5 mt/ha) for 70 DAE. As shown in Figure 1, the difference between total seed yield and quality seed yield is highest at early harvests. After 80 DAE, difference between total seed yield and quality seed yield was more or less similar up to 90 DAE.

Figure 1. Variation of quality seed yield, total seed yield and quality seed percentage with harvesting time

Conclusion80-90 days after emergence period can be considered as the best period for

bean seed harvesting without significantly affecting seed yield, quality seed yield & 100 seed weight. Therefore, it is advisable to harvest dry pods for seed extraction at 80 DAE soon after reaching to physiological maturity.

47

ReferencesAbdul-Baki, A.A. and J.D. Anderson. 1973. Physiological and biochemical deterioration of

seed. In: Seed Biology (II Ed): Kozlowski, T.T., Academic Press, New York, London. 283-315.

Greven, M.M., B.A. McKenzie, J.G. Hampton, M.J. Hill, J.R. Sedcole, and G.D. Hill. 2004. Factors affecting seed quality in dwarf French bean (Phaseolus vulgaris L.) before harvest maturity. Seed Science and Technology. 32(3): 797-811.

Gridley, H.E. and D.L. Danial. 1995. Bean production constraints in Africa with special reference to breeding for resistance to common bean mosaic virus. Proceedings of a regional workshop for eastern, central and southern Africa, Wageningen Agricultural University, Wageningen. 35 - 41.

Khatun, A., M.A. Bhuiyan, A. Nessa and S.M. Byazid Hossain. 2010. Effect of harvesting time on yield and yield attributes of chickpea (Cicer arietinum L.). Bangladesh Journal of Agricultural Research. 35(1): 143-148.

Kumar,V., S.D. Shahidhan, M.B. Kurdikeri, A.S. Channaveeraswami and R.M. Hosmani. 2002. Influence of harvesting stages on seed yield and quality in paprika (Capsicum annuum L.) Seed Research. 30(1): 99-103.

Mehta, C.J., M.S. Kuhad, I.S. Sheoran, and A.S. Nandwal. 1993. Studies on seed development and germination in chickpea cultivars. Seed Research. 21(2): 89-91.

Shaheb. M.R., M.N. Islam, A. Nessa and M.A. Hossain. 2015. Effect of harvest times on the yield and seed quality of French bean. SAARC J. Agri., 13(1): 01-13.

Wortmann, C.S. and D.J.Allen. 1994. African bean production environments: their definition, characteristics and constraints. Network on Bean Research in Africa, occasional paper series No. 11, Dar-es Salaam.



Response of selected rice varieties for salt stress at different stages of life cycle

R.M.N.H. Senanayake1, H.M.V.G. Herath2, I.P. Wickramesinghe2, U.A.K.S. Udawela1, H.M.L.U. Sandaruwan1, D.G.K.P. Wijerathna1 and

W.G. Wijepala1

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka,

2Department of Agric. Biology, Faculty of Agriculture, University of Peradeniya, Sri Lanka

IntroductionSoil salinity, especially in rice growing soils is a major constraint to expand

rice cultivation. The productivity of rice is greatly affected by soil salinity which is the second most widespread soil problem after drought in rice growing areas in the world. Soil salinity has the potential to reduce national rice production significantly. It affects all growth stages of rice in varying degrees starting from germination up to maturation. Though there were developed salt tolerant varieties, their level of salt tolerance and stage of salt tolerance have not been estimated properly. Therefore, the present study was carried out to identify salinity tolerance of the popular local rice varieties, which are grown in salinity affected areas in Sri Lanka to group those varieties based on their salinity tolerance level at different stages of the life cycle. Further, rice varieties were tested for their ability to sustain seed viability at germination, growth performance of seedling and plant survival, growth performance and grain yield reduction at maturity under salt stress.

Materials and methodsThe research was conducted at the Rice Research and Development Institute,

Batalagoda, Sri Lanka. The study was carried out over four consecutive seasons namely, Yala 2014, Maha 2014/15, Yala 2015 and Maha 2015/16. Twenty one improved rice varieties namely Bg 379-2, Bg 450, At 402, Bg 403, Bg 406, Bg 94-1, Bg 352, At 353, At 354, Bg 357, Bg 358, Bg 359, Bg 360, At 362, Ld 365, Bg 366, Bg 369, Bg 300, Bg 4-91, At 307, At 308 and check variety Pokkali were tested at seed germination, seedling, seedling to harvesting and booting to harvesting stages in petri dishes under hydroponic system and in soil filled pots respectively. The varieties were selected based on coverage of the saline rice lands in the country.

49

Response to salt stress at seed germination stageAs proposed by Abeysiriwardena (2004), varieties were screened for their

ability to sustain seed viability under high salt concentrations. The experiment was a variety (22) X salt concentrations (4) X soaking periods (2), three factor factorial laid out in a Completely Randomized Design (CRD) with 2 replications. Experiment was repeated twice to determine the consistency of results. Sodium chloride solutions were prepared having electrical conductivity (EC) levels of 0, 40, 45 and 50 dS/m and fifty seeds from each variety were soaked in the solutions for 9 and 12 days in petri dishes. Washed seeds were allowed to germinate under ambient temperature after completing the soaking period. The average temperature inside the laboratory during the study period was 27 ºC. Number of germinated seeds were counted for each variety in each replicate after 5 days.

Response to salt stress at seedling stageThe varieties were screened for salt tolerance in a hydroponic system using

International Rice Research Institute (IRRI) standard protocol at seedling stage (Gregorio et al., 1997). Three replications were used in the experiment. The evaluation was performed using the nutrient solution proposed by Yoshida et al. (1976). The modified Standard Evaluation System (SES) was used in rating the visual symptoms of salt toxicity (IRRI, 1997). Initial and final scorings were performed 10 and 16 days after salinization.

Salt stress imposed at seedling stage up to harvestingThe varieties were evaluated for their tolerance to salinity in a pot experiment

based on the performance of the mature plants under saline conditions. NaCl was added at the rates of 0, 6, 12 and 18 g per 5 kg soil pot to obtain the salinity levels of 0, 4, 8 and 12 dSm-1 respectively. Three weeks old rice seedlings of 22 varieties were planted at the rate of 3 plants per pot. Saturated moisture level was maintained in each pot throughout the growing season until maturity. The experiment was variety (22) X salinity levels (4), two factor factorial laid out in a CRD with three replications. Data were recorded for survival of plants per pot, plant height (PH), panicle length (PL), root dry weight (RDW), shoot dry weight (SDW), panicle weight (PW), panicle number per plant (PN) and grain yield per plant (GY).

Salt stress imposed at booting stage up to harvestingThe varieties were evaluated for their tolerance to salinity by using pot

experiment to study the performance of the plants at booting stage under saline

50

conditions. Three weeks old rice seedlings of the above 22 varieties were planted as 3 plants per pot. At the booting stage NaCl was added at the rates of 0, 6, 12 and 18 g per 5 kg of soil pot to get the salinity levels of 0, 4, 8 and 12 dSm-1, respectively. Saturated moisture level was maintained in each pot throughout the growing season until maturity. The experimental design was CRD with three replications. Data were recorded for survival plants per pot, PH, PL, RDW, SDW, PN, and GY.

Results and discussionResponse to salt stress at seed germination stage

Combinations of soaking periods and different salt concentrations were used to identify salinity tolerance level of 22 rice varieties at seed germination stage. Three way interaction effect of variety X soaking period X salt concentration and two way interaction effects of variety X soaking period, variety X salt concentration and soaking period X salt concentration were found to be significant at 0.01 probability levels. According to the mean separation, selected rice varieties can be categorized in to 6 groups with their response to salinity at the best combination of the 12 days of soaking and 50 dSm-1 salt concentrations. Highest germination percentage was observed in Bg 406 as compared to other varieties at all salt stress levels.

Response to salt stress at seedling stageBased on the mean separation of score percentage of survival, varieties showed

significant differences (p<0.01). According to the mean separation the varieties are categorized in to five levels of stress response. In this study of twenty two rice varieties, an improved variety At 402 was found to be highly tolerant to the 12 dSm-1 salt stress. It has shown 100% of survival score percentage. Also check variety, Pokkali and newly improved varieties, At 354 and Bg 369 were identified as salt tolerant varieties at the seedling stage according to mean separation and also showed 75% of score percentage after 10 days salinization.

Salt stress imposed at seedling stage up to harvestingThe analysis of variance showed that there is a very high significant difference

among the salinity levels in to the varieties interactions for the parameters taken. The two way interaction effect of variety X salt concentration was significant with PH, PL, RDW, SDW, PW, PN, and GY. According to the cluster analysis, selected 22 rice varieties can be categorized in to six levels of tolerance. Range of the percentage reduction of the phenotypic traits at 8 dSm-1 and 12 dSm-1 salt concentrations after seedling stage up to maturity and their level of tolerance were presented in Table 1.

Senanayake et al.

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Salt stress imposed at booting stage up to harvestingThe two-way interaction effect of variety X salt concentration was significant

with PH, PL, RDW, SDW, PN, GY and PS%. PH, PL, RDW, SDW, PN and GY of the tested varieties decreased with the increasing salt levels. In this experiment salinity induced at the booting stage while considering the age of the rice varieties. Influences of different salinity levels at reproductive stage on the phenotypic traits were highly significant beyond 8 dSm-1 salt stress. Analysis of variance indicated that the difference among varieties for the phenotypic traits were highly significant. According to the cluster analysis, selected 22 rice varieties can be categorized in to six levels of tolerance (Table 1).

Varietal Response to Salt Stress across the life cycleAccording to the overall results of the varietal response in different stages of

the life cycle Bg 406 is the only one newly improved variety, which is having better response for salt stress in all growth stages. As well as, At 402, Bg 369 and At 354 performed better beginning from seedling up to maturity. Therefore, those varieties can be identified as promising salinity tolerant varieties from the selected rice varieties.

The effect of salinity on rice may vary depending on the stage of its life cycle at which it is exposed to salinity. Several studies indicate that rice is tolerant to salinity during germination but young seedlings are sensitive (Flower and Yeo, 1981). Moormann and Breeman (1978) cited that the damage to the plant during transplanting increases its sensitivity to salinity. Further it is mentioned that the salt tolerance increases during tillering, but the plant again become sensitive during flowering.

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Table 1. Varietal response to salt stress across the life cycleVarieties Salt stress imposed across the life cycle

Germination Seedling At seedling stage up to harvesting

At booting stage up to harvesting

At 307At 308At 353At 354At 362At 402Bg 300Bg 352Bg 357Bg 358Bg 359Bg 360Bg 366Bg 369Bg 379-2Bg 4-91Bg 403Bg 406Bg 450Bg 94-1Ld 365Pokkali

HT T MT MS S HS

However, susceptibility to salt stress is most severe at the seedling and reproductive phases, eventually leading to significant reductions in grain yield and yield components. Zeng et al. (2001) found that the stage from the initiation of the third leaf to panicle initiation as the most sensitive to salinity in terms of seed yield. Thus, the spikelet number per panicle was more sensitive to salinity and it has shown a varietal variation as well. Some varieties were highly sensitive to salinity at the germination and early vegetative stages, but were tolerant at the reproductive stage. The others showed tolerance at germination but sensitivity at the subsequent stages (Heenan et al., 1988). However, Moradi et al. (2007) stated that tolerance of rice to salinity at the seedling stage is weakly correlated with tolerance at the reproductive stage.

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ConclusionAccording to the overall results of the varietal response in different stages of the

life cycle, Bg 406 was categorized in moderately tolerant or highly tolerant throughout the life cycle. Varieties, At 402, Bg 369 and At 354 were categorized tolerant or highly tolerant after the germination stage. Therefore the varieties Bg 406, At 402, Bg 369 and At 354 can be identified as promising salinity tolerant varieties from the selected rice varieties.

ReferencesAbeysiriwardena, D.S. and Z. De. 2004. A simple screening technique for salinity tolerance for

rice germination rate under stress: Int. Rice Res. Notes. 29 (2): 78-79.

Flower, T.J. and A.R. Yeo, 2000. Salinity effects on the seedling growth and yield components of rice. Crop Sci. 40: 996-1003.

Gregorio, G.B., D. Senadhira, and R.D. Mendoza. 1997. Screening rice for salinity tolerance, IRRI Discussion Paper Series. International Rice Research Institute. Los Banos. Laguna. Philippines. 22.

Heenan, D.P., L.G. Lewin and D.W. McCaffery. 1988. Salinity tolerance in rice varieties at different growth stages. Australian journal of experimental Agriculture. 28(3): 343-349.

International Rice Research Institute. 1997. Rice Almanae. IRRI-WARDA-CIAT, Los Baños, Laguna, Philippines.

Moormann, F.R. and N.V. Breeman. 1978. Salinity and alkalinity in rice lands. Rice, Soil, Water, Land. IRRI. 121-131.

Moradi, F. and A. M. Ismail. 2007. Response of photosynthesis, chlorophyll fluorescence and ROS- scavenging systems to salt stress during seedling and reproductive stages in rice. Annals of botany. 99(8): 1161-1173.

Yoshida, S., D.A. Forno, J.H. Cock and K.A. Gomez. 1976. Laboratory Manual for Physiological Studies of Rice. International Rice Research Institute (IRRI), Los Banos, Laguna, Philippines. 61-66.

Zeng, L., M.C. Shannon and S.M. Lesch. 2001. Timing of salinity stress affects rice growth and yield components. Agricultural Water Management, 48: 191-206.

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Toxicity of herbicide, Diuron 480 g/l SC to cultivated rice

R.M.U.S. Bandara1, B. Marambe2, W.M.U.B. Wickrama1, Y.M.S.H.I.U. de Silva1, H.M.M.K.K.H. Dissanayaka1, D.M.C.B. Dissanayake1 and

P.R.T.E.W.M.R.B. Ekanayake3

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka

2Department of Crop Science, Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka

3Lankem Ceylon PLC, Sri Sangaraja Mawatha, Colombo, Sri Lanka

IntroductionDiuron, a systemic substituted phenyl urea herbicide, is easily taken up from

soil solution by the root system of plants and rapidly translocated to stems and leaves via the xylem. Diuron inhibits the Hill reaction in photosynthesis, limiting the production of high-energy compounds such as Adenosine triphosphate (ATP) used for various metabolic processes. During the process lipids and proteins are attacked and oxidized (Hess and Warren, 2002), resulting in the loss of chlorophyll and carotenoids, and leaky membranes leading to drying of cells and cell organelles and their rapid disintegration.

Over the years paddy farmers in Sri Lanka used to apply total killer herbicides such as paraquat and glyphosate prior to and during land preparation of rice for weed control as per recommendation of the Department of Agriculture (Marambe et al., 2015). With the ban imposed on import and use of paraquat in 2014 and glyphosate in 2015 (Rao et al., 2017), Diuron has been reportedly used by the paddy farmers as an alternative for weed control, though the herbicide has not been recommended for rice cultivation (Abeysekara et al., 2015), A few cases were even reported to the Rice Research and Development Institute (RRDI) at Batalagoda, Sri Lanka on the crop damages owing to phytotoxicity of Diuron on germinated rice seedlings. Therefore, the situation warranted a study to understand how pre-tillage application of Diuron affects rice crop in order to educate the farmer community in the use of the herbicide. Thus, the present study was focused on assessing the impact of pre-tillage application of Diuron on early growth of rice seedlings.



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Materials and methodsPot experiments were conducted in a Completely Randomized Design (CRD)

during the Yala season (March-September) 2015 at the Rice Research and Development Institute (RRDI) at Batalagoda in Sri Lanka to study the phytotoxicity of the herbicide Diuron 480 g/l SC on cultivated rice (Oryza sativa L), variety Bg 300 (three-months age class). Thirty six clay pots (30 cm height x 30 cm inner mouth diameter) were filled with top soil (Reddish brown earth, Low humic gley soil, Immature brown loam) collected from a paddy field up to the height 28 cm. Diuron was applied using a 16 l of knapsack sprayer at the rate of 1800 l/ha to 50% of the pots on the same day while the rest was treated with water (control).

Thereafter, the experiment was divided into six separate sets (S1-S6) as described below. In each set, three pots each from herbicide-treated and the control were sown with 100 seeds of un-soaked seed paddy at different dates after herbicide treatment, i.e. on the same day as the herbicide treatment (S1), first day of the 2nd week after herbicide treatment (S2), first day of the 4th week after herbicide treatment (S3), first day of the 6th week after herbicide treatment (S4), first day of the 8th week after herbicide treatment (S5) and first day of the 10th week after herbicide treatment (S6).

Seed paddy was not pre-soaked to assess the impact of the herbicide treatments on seed germination. Thereafter, all pots were watered until the soil reached saturation. Germination was estimated by the initial number of emerging seedlings, and the seedling counts were taken at weekly intervals for four weeks after sowing (WAS). The percentage seedling survival in herbicide-treated pots was calculated.

Results and discussionGermination of seed paddy was not affected by the herbicide treatments (Figure

1-6: S1-S6). However, in all experimental sets (S1-S6), the percentage seedling survival rice seedlings in the Diuron-treated plots decreased rapidly with time compared to the respective control. In all sets, seedling mortality was observed since 1 WAS with 100% mortality recorded at 2-4 WAS, suggesting the high phytotoxicity of the herbicide to initial growth of rice plants. The phytotoxicity of the herbicide was strongly evident even at 12 WAS (Figure 6: S6).

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Figure 1. Percentage Seedling Survival in Set 01



Perc

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Surv

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Duration from Diuron application (Weeks)


Duration from Diuron application (Weeks) Duration from Diuron application (Weeks)






Bandara et al.

57

Establishment of the root systems is a requirement for Diuron to be absorbed by plants and hence, the seedling growth of rice was affected, but not the seed germination. The results also revealed that the phytotoxicity of Diuron was evident even after 12 WAS indicating its long persistence in soil.

ConclusionDiuron 480 g/l SC at the rate of 1800 l/ha, which is recommended as pre-

emergence weed control for other field crops is toxic to rice plant. The herbicide persisted in the soil even after 12 weeks from the application. Therefore, Diuron cannot be recommended as a pre-tillage herbicide in paddy cultivation at the rates tested in this study.

ReferencesAbeysekara, A.S.K., L.D. Galaniha, C. Magamage, S.S. Weligamage, W.A.R.T. Wickramarachchi

and G.A.W. Wijesekara. 2015. Pest Management Recommendations, Department of Agriculture, Peradeniya, Sri Lanka.

Hess, D. and F. Warren. 2002. The Herbicide Handbook of the Weed Science Society of America, 8th Edition. Weed Science Society of America, Westminster, USA. 159-161

Marambe, B., A.S.K. Abeysekara and H.M.S. Herath. 2015. Weeds and weed management in agricultural and natural ecosystems: an overview of the Sri Lankan context. In: Weed Science in the Asian-Pacific Region, Chapter 9, Eds. V.S. Rao, N.T. Yaduraju, N.R. Chandrasena, Gul Hassan and A.R. Sharma, Asian-Pacific Weed Science Society and Indian Society of Weed Science, Hyderabad. 213-240.

Rao, A.N., S.P. Wani, S. Ahmed, H.H. Ali and B. Marambe. 2017. An overview of weeds and weed management in rice in South Asia. In: Weed management in rice in the Asian-Pacific region. Eds: A.N. Rao and H. Matsumoto. Asian Pacific Weed Science Society, TheWeed Science Society of Japan and Indian Society of Weed Science. 247-281.

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Effect of stem pruning and fruit thining on yield and quality of bell pepper in poly house

I.C.S. Edirimanna, H.M.V.S. Dharmasena, S.M.U.I. Samaraweera and A.M.R. Darshana

Regional Agriculture Research and Development Centre, Bandarawela, Sri Lanka

IntroductionCapsicum annum L. commonly known as sweet pepper as well as bell pepper

has gained popularity within horticultural sector in Sri Lanka. In vegetable greenhouse production profits are greatly dependent on high yield and quality per unit area. Plant spatial arrangement is a crop management practice that has been used to increase yield per unit area in greenhouse sweet pepper (Verheij and Verwer, 1971; Guo et al., 1991, Cebula, 1995; Lorenzo and Castilla, 1995). In commercial green house, fruit development in pepper crops is controlled by restricting the branching pattern 2 or 4 main stems. The reason for pruning sweet pepper under greenhouse conditions is to train plant growth to facilitate light penetration throughout the leaf canopy for more efficient interception of light (Guo et al., 1991). The present study was conducted to determine the effect of stem pruning and immature fruit thinning on bell pepper fruit yield and quality in a poly tunnel condition.

Materials and methodsAn experiment was conducted in 1000 ft2 poly tunnel at Regional Agriculture

Research and Development Centre, Bandarawela in 2015 and 2016. Four weeks old seedlings of cultivar Pollaris were transplanted into 12 inch plastic growing pots filled with coir dust media. Three stem pruning methods (2,4 without pruning) and two immature fruit thinning practices (fruit removing alternatively, without fruit removing) were arranged in a Complete Randomized Design with ten replicates. Pots were arranged as double row system with 60 x 45 cm plant spacing with 1m walking path.

In order to encourage initial vegetative growth, first (crown flower) were pulled from the plants in all treatments. Plants were irrigated manually with a complete nutrient solution (Albert’s solution) and irrigation volume was gradually increased as the plants developing stages as follows (Table 1).



59

Table 1. The composition and chemical concentration of fertilizers used in research trialFertilizer Water

Application stage

Albert’s solution (g/day)

Calcium Nitrate

Application stage

Amount (ml)

Until 2 days - - Until 2 days 250Until 3 weeks 0.50 2-8 weeks 5004-6 weeks 0.75 After fruiting

2g/plant/week>8 weeks 1000

7-10 weeks 1.00>10 weeks 1.50

Four weeks after transplanting the plants were trained using a ‘V’ trellising system. As the treatments, healthiest two or four branches were allowed to grow continuously as ‘V’ system by removing other weak branches and leaves. Side branches and immature fruits were removed weekly to maintain the number of stems and fruits as per treatments. Data collection was done from mature fruits, at the initial stage of colour changing (green to yellow), which were harvested every 8 to 10 days.

A factorial analysis of variance (ANOVA) was used to test for significant effects of treatments and mean separation were done using least significant differences (LSD) at the 5% level of significance (Snedecor and Cochran, 1980).

Results and discussionStem pruning was significantly affected on plant height after first pruning.

Plants pruned to two and four stems produced significantly higher number of marketable fruits than without pruned treatments. The highest number of unmarketable fruits was observed in without stem pruned treatment compared to two and four stem pruned (Table 2). Reduced unmarketable fruits on plants pruned to two to four stems might be the results of optimum sunlight need for the growth (Guo et al., 1991). Our results showed that plants pruned to two and four stems produced significantly similar total yield compared to without stem pruned treatment during both seasons. Lowest average fruit weight was recorded in without pruning treatment in 2015 and stem pruning method was not significantly affected on diameter of fruits.

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Table 2. The effect of stem pruning on final yield of bell pepper No. of

marketable fruitsNo. of

unmarketable fruitTotal weight of

fruit (g)2015 2016 2015 2016 2015 2016

Stem pruning2 stem 7.5a 11.3a 3.9b 1.9b 1935.2a 3663.9a

4 stem 7.4a 11.4a 3.8b 2.0b 1954.7a 3808.2a

Without pruning 6.5b 9.6b 6.6a 3.9a 1844.5a 3713.4a

Significance * * * * NS NSFruit thinningFruits remove alternatively 7.3a 10.7a 4.5a 2.7a 1949.4a 3821.2a

Without fruit removing 7.0a 10.2a 5.0a 2.5a 1874.1a 3635.8a

Significance NS NS NS NS NS NSInteraction NS NS NS NS NS NS

Significance at the 5% level or non significant (NS), respectively. Mean separation by Duncan’s Multiple Range Test at 5% probability

Stem pruning methods responded differently to fruit grades (Figure 1 and Figure 2). The higher number of extra large and large fruits was shown in two and four stem pruned plants compared to without pruned treatments. On the contrary, medium and small number of fruits was higher in without stem pruning treatment compared to two and four stem pruned plants. During both years (2015 and 2016) fruit removing did not show a significant influence on plant growth and yield parameters of bell pepper.

Figure 1. The effect of stem pruning on number of fruits as grade in 2015

Figure 2. The effect of stem pruning on number of fruits as grade in 2016

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ConclusionThe results demonstrate that, plants pruned to two stems and four stems

improved marketable fruit yield and higher grade (extra large and large) fruit yield. The results of the present study also indicated that fruit removing was not affected positively on total fruit yield or any other considerable factors of bell pepper grown in poly tunnel.

ReferencesCebula, S. 1995. Optimization of plant and shoot spacing in greenhouse production of sweet

pepper. Acta Hort. 321-338.

Guo, F, C.Y. Fujime, T. Hirose, T. and T. Kato. 1991. Effects of the number of training shoots, raising period of seedlings and planting density on growth, fruiting and yield of sweet pepper. J. Japan. Soc. Hort. Sci. 59: 763- 770.

Lorenzo, P. and N. Castilla. 1995. Bell pepper yield response to plant density and radiation in unheated plastic greenhouse. Acta Hort.32:149-158.

Snedecor, G.W. and W.G. Cochran. 1980. Statistical Analysis Methods. 6th Ed. Iowa state Uni V.Press.Ames., Iowa,USA.

Verheij, E.W.M. and F.L.J. Verwer. 1971. Light interception and yield of peppers grown under glass in relation to plant spacing. Acta Hort. 32: 149-158.

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Influence of drip irrigation regimes on tuber yield of King yam (Dioscorea alata L.) in Red Yellow Latosol soils

S.J. Arasakesary and A. Amirthalojanan

Regional Agriculture Research and Development Centre, Iranaimadu Junction, Kilinochchi, Sri Lanka.

IntroductionYam (Dioscorea spp.) is a multi-species crop that belongs to the family

Dioscoreaceae within the genus Dioscorea and serves as a staple food for over a billion people in the tropical nations of Africa, Asia, the Caribbean and the Pacific region (Lebot, 2009). The yam tuber, which is the most important part of the plant, can be stored longer than other root and tuber crops, ensuring food security even at times of general scarcity. It is the third most important tropical root and tuber crop after cassava and sweet potato (Fu et al., 2005).

Drought has become the prime limiting factor of plant production in the world. Dry periods are more frequent in Dry zone agriculture. Therefore, supply of water is the most critical practise affecting growth and development of all agricultural crops including tropical root crops. Water supply is particularly important for the germination and establishment of all roots crops. It needs to be evenly distributed (2.5 cm/week) as these crops are very susceptible to short periods of drought, especially in the last 9 weeks of growth. Inadequate water supply lead not only yield reduction but also malformed tubers (Wilson, 1977). However, high-intensity irrigation not always increases the yields significantly in comparison to the medium-intensity irrigation (Elzner et al., 2018). Advantages of drip irrigation in comparison to conventional irrigation include reduced soil nutrient washout (Shock et al., 2007). Therefore a study was conducted to investigate the effects of well-designed drip irrigation system with different intervals in King yam yields.

Materials and methodsThis experiment was carried out at the Regional Agriculture Research and

Development Centre (RARDC), Kilinochchi, to examine the effects of different drip irrigation intervals on the yield, yield components and agronomic performance of local collection of Dioscorea during the period of July 2018 to March 2019. The experimental site was low land which comes under Agro ecological region DL3 and



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having Red Yellow Latasols with well-drained soil. Maximum/Minimum temperature, relative humidity and rainfall data also were recorded during the testing period using standard implements. Physical and chemical properties of the soil in the experimental plot are shown in Table 1.

Table 1. Soil properties of the 0-0.3 m layer in the experiment plot.Soil Type Bulk density

g/cm3Volumetric

Moisture content at Field capacity (%)

Soil pH

Electric conductivity (1:5) (ds/m)

Soil organic matter (%)

Sandy loam 1.71 21.08 6.31 17.56 0.82

Randomized Complete Block Design (RCBD) was used with three replicates. The treatments were allocated in 10 x 3 m plots to facilitate 20 plants with 1x1 m spacing. Drip systems were designed to irrigate 10 plants with each line (altogether 32 lines). Each replicate had 8 lines in order to facilitate 2 lines (20 plants) for a treatment. Plants were supplied with 2 drippers with 15 cm distance from plant hole with the capacity of 4 l/hr at 2 bar pressure. Each plot was separated from 1 m width space to avoid lateral movement of water among treatments. Irrigation intervals were selected as every day, every alternate day, 2 days interval and 3 days interval. The amount of irrigation was determined based on the evaporation data using pan readings. The amount of irrigation for each interval was calculated based on climatological approach using both the crop co-efficient (Kc) for tuber crops and daily evaporation data. All recommended cultural practices and plant protection measures were adopted as per the Department of Agriculture recommendations. Data on yield parameters Viz: Number of bulbils per plant, weight of bulbils (mt/ha), number of tuber per plant, weight of tuber per plant (kg) and plot yield (mt/ha) were recorded from randomly selected ten plants from each replicates. Collected data were statistically analyzed using SAS-9.1 computer program.

Results and discussionTemperature, Relative Humidity and Rainfall data recorded in experiment site

were revealed that high precipitation with prominent temperature and suitable relative humidity were received in October, November and December months which created favorable cropping condition for planting (Table 2). King yam is usually cultivated during July to march in Northern part of Sri Lanka. It creates favourable rain-fed cultivation in middle stage of crop production. Therefore, initial stage and late stage production are mainly influenced by different drip irrigation intervals during this

64

study. Kc values and crop stage indicator for tuber crops were used based on water conservation fact sheet, Ministry of Agriculture, food and fisheries, British Columbia.

Table 2. Meteorological data at research station during cultivation periodMonths Temperature (oC) Relative Humidity (%) Rainfall

(mm)Maximum Minimum Morning EveningAugust (25-31) 34.5 24.0 75 65 0September 34.3 24.2 76 67 77.0October 30.7 23.8 87 82 342.5November 29.5 23.1 89 83 397.9December 28.9 23.0 88 84 469.3January 29.2 21.3 79 67 1.9February 31.6 23.5 83 66 0March(1-28) 34.1 23.8 78 57 29.3

Table 3. Kc Value, Average irrigated water (mm) and average water applied time (min) for each drip irrigation intervals

Crop Stage Initial Mid-Season Late SeasonKc 0.5 1.05 0.95Days 40 90 90Every day Average applied water 1.9 mm - 2.2 mmAverage applied time 9.54 min 11.53 minEvery alternate dayAverage applied water 3.8mm - 4.4 mmAverage applied time 20.12 min 23.31 min2 days intervals Average applied water 4.9 mm - 6.5 mmAverage applied time 30.34 min 35.22 min 3 days intervalsAverage applied water 6.1 mm - 8.6 mmAverage applied time 39.46 min 47.07 min

There was no any irrigation in mid-season because the adequate soil moisture was automatically maintained. But, this seasonal change is regular in northern region and king yam cultivation season also comes within this seasonal change in every year. Average soil moisture before irrigation in all treatments were decreased from field capacity and moisture content under different intervals showed a declining trend with increasing drip irrigation intervals (Figure 1).

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Figure 1. Average soil volumetric moisture contents (%) before Drip irrigation in all different irrigation intervals.

Every day (21.34%) and every alternative day (24.28%) showed acceptable volumetric moisture depletion when compared to 2 days interval (32.27%) and 3 days intervals (45.57%) respectively. Eid et al. (2013) reported that the maximum yield of potato tubers was reached at 25% depletion of available moisture while 70% depletion resulted the lowest yield.

Results revealed that there was no significant difference observed in number of bulbils per plant and number of tubers per plant and bulbils yield among treatments (Table 4).

Table 4. Effects of drip irrigation intervals on tuber and bulbils yield of King yam.Watering interval

Number of bulbils per plant

Weight of bulbils(t/ha)

Number of tuber per plant

Weight of tuber per plant (kg)

plot yield (t/ha)

Irrigated Water

productivity (kg/l/plant)

Every day 5.07a 0.740a 2.033a 1.504a 15.037a 0.017a

Every other day

4.76a 0.626a 1.936a 1.331ab 12.688ab 0.015ab

Without 2 days

4.26a 0.606a 1.500a 1.197ab 11.643ab 0.014ab

Without 3 days

3.83a 0.478a 1.986a 1.002b 9.023c 0.011c

LSD 2.42 0.33 0.61 0.42 4.45 0.004CV 27.04 26.99 16.42 16.78 18.41 16.75

Means in each column with the different letters indicate significant different at p<0.05 with coefficient of variability (CV).

Watering Interval

Soil

Volu

met

ric m

oist

ure

cont

ent (

%)

Every day Every otherday Without 2 days Without 3 days

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However, the results also showed that average bulbils yield was increased when reduced the watering interval. Every day watering interval showed significant (p<0.05) yield increase (15.037 t/ha) in tuber weight per plant and plot yield than 3 days watering interval. There were no significant yield difference recorded among every day, every alternate day and 2 days interval of drip irrigation intervals. But, considerable yield difference were observed in those treatments as increasing yield with decreasing drip irrigation intervals. Irrigated water productivity also was calculated using drip irrigated water amount, which showed significant (p<0.05) water use efficiency (0.017 kg/l/plant) in every day drip irrigation than the condition of 3 days without water (0.011 kg/l/ plant).

ConclusionDaily and alternate day irrigation with drip system has increased yield

parameters of king yam in Red Yellow Latosols during the conventional growing season in Northern Sri Lanka.

ReferencesEid, T.A., S.M.M. Ali and N.H. Abou-Baker. 2013. Influence of soil moisture depletion on

water requirements, yield and mineral contents of potato. Journal of Applied Sciences Research. 9(3): 1457-1466.

Elzner, P., M. Jůzl and P. Kasal. 2018. Effect of different drip irrigation regimes on tuber and starch yield of potatoes. Plant, Soil and Environment. 64(11): 546-550.

Fu,Y.C., P.Y. Huang and C.J. Chu. 2005. Use of continuous bubble separation process of separating and recovering starch and mucilage from yam (Dioscorea pseudojaponica Yamamoto). LWT. 38 (7): 735-744. DOI: 10.1016/j.lwt.2004.09.008.

Lebot, V. 2009. Tropical Root and Tuber Crops: Cassava, Sweet Potato, Yams and Aroids. Crop Production Science in Horticulture Series: 17. CABI, Wallingford.

Shock, C.C., A.B. Pereira, and E.P. Eldredge. 2007. Irrigation best management practices for potato. American Journal of Potato Research. 84(1): 29-37.

Wilson, L.A. 1977. Root crops. Ecophysiology of tropical crops, 187236.

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The cyanogenic potential of roots and leaves of released cassava (Manihot esculenta Crantz) varieties in Sri Lanka

N.L.A.T.S. Nanayakkara1, G.G.C. Premalal2, S.M.S A. Sumathipala, E.R.I.B.N.N. Jayalath2 and N.N. Rajapaksha1

1Horticultural Crops Research and Development Institute, Gannoruwa, Sri Lanka2Veterinary Research Institute, Gannoruwa, Sri Lanka

IntroductionManihot esculenta Crantz, commonly known as cassava, belongs to the family

Euphorbiaceae and genus Manihot having a great economic interest. Cassava species are classified into three groups according to their CP levels.

1) Sweet or nontoxic levels with less than 50 ppm. 2) Moderately poisonous with 50-100 ppm and 3) Bitter, toxic or very poisonous containing CP more than 100 ppm (Hidayat et al., 2016). For Human the lethal dosage is 1 mg/kg of live weight (Chen et al., 2018). Trivalent iron of cytochrome oxidizer is reacted with cyanide. Cyanide causes neurological, respiratory cardiovascular and thyroid defects, and ultimately the death. (Drochioiu et al., 2011). Therefore it is recommended to consume cassava with Cyanogenic potential (CP) levels less than 50 ppm. (Hidayat et al., 2016).

Both roots and leaves are consumed. Cassava leaves are a rich source of protein, calcium, and vitamin and used as a leafy vegetable. Highest amount of the cyanogenic potential exists in immature parts and it is safer to eat the leaves bellow the third leaf from the top (Hidayat et al., 2016). Many cultivars are grown all over the country in Sri Lanka, but their cyanide content is still unknown. Seven cassava varieties have been released by the Department of Agriculture. This study was initiated to determine the cyanide levels of roots and leaves of released varieties to clarify some doubtful points, vomiting and headache after consuming Kirikawadi have been reported occasionally. Therefore all the varieties were tested again to clarify the cyanide levels. All the released cassava varieties contain CP less than 50 ppm. Cyanide content of cassava leaves and roots varied with age, and parts of the crop, nitrogen content of the soil. Crop harvesting stage, poor weeding practices, piecemeal harvesting and branch pruning influence the cyanide levels (Imakumbili et al., 2019). Further studies has to be done with different agronomic traits to make sure the cyanide contents in different conditions.



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Materials and methods The study was carried out in the experimental field of the Horticultural Crops

Research and Development Institute (HORDI), Gannoruwa, Peradeniya during April to December 2016, using eight month old cassava varieties released by the DOA. Varieties were Suranimala, MU51, Kirikawadi, CARI 555, Swarna, Shani and HORDI MU 01. Crop was established before 8 months from the date of sampling and management practices were followed according to the DOA recommendations.

Chemical analysis for cyanide was done in the Pasture Division, Veterinary Research Institute (VRI) Gannoruwa, Peradeniya using Alkaline Picrate Spectrophotometric Method (Biology-assets.anu.edu.au., 2019). Roots, with and without cortex separately, and mature leaves (below third leaf) and immature top leaves (third and above) were subjected to test the HCN levels on a CRD experiment with three replicates.

The roots were cleaned and peel out the outer brown skin and cut in longitudinal direction into 1 inch sections with and without inner cortex separately. Root and leaf samples were minced using a laboratory blender. Five grams of root sample sand 1 g of leaf sample were measured and put immediately into 50 ml centrifuge tubes, and added 3-5 drops of chloroform, 2 ml of distilled water and 1 ml phosphate buffer solution (0.1M). All tubes were shacked well after closing the lid. Thereafter, 2 ml of 1% NaOH was added in to separate 5 ml small plastic vial and insert in to the centrifuge tube by removing the lid. Tubes were kept overnight (12 hrs) at room temperature or 2 hrs at 37 oC water bath to trap HCN in to NaOH. In the following day, cyanide reacted NaOH solution in small vial was transferred in to a another 50 ml Nessler tube and add 5 ml of picric buffer regent and 6 ml of distilled water and shacked well. Cyanide levels of each sample was measured with standards at 520 nm. Data were analyzed using ANOVA in SAS (Statistical Analysis Software) version 9.1 and means were compared using Duncans Multiple Range Test (DMRT).

Results and discussionAll the varieties showed cyanide levels less than 50 ppm in both leaves and

roots. Roots were tested as two groups, with cortex and without cortex. Out of tested varieties significantly higher cyanide level was observed in variety Kirikawadi in roots without cortex. Variety Kirikawadi, showed the highest cyanide levels with cortex followed by Suranimala, Mu51, CARI555. HORDI and MU-1. The lowest cyanide level was observed in Variety CARI 555 in root flesh without cortex (16.17 ppm).

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Variety Shani had the second lowest cyanide level (21.01 ppm) in root flesh without cortex. Significantly highest cyanide value was observed in variety Kirikawadi without cortex (Table 1).

Highest cyanide content was observed in immature top leaves in all varieties (3rd leaf and above) mature leaves (4th-6th) had less cyanide levels. Kirikawadi and CARI 555 gave the highest significant cyanide levels up to 26-30 ppm in immature top leaves. Significantly highest cyanide level 8.41 ppm was observed in variety Kirikawadi in mature middle leaves. All the varieties gave significantly low cyanide value than variety Kirikawadi in middle leaves. Variety HORDI MU-1, Shani and MU-51 gave the lowest cyanide value in middle mature leaves. All the varieties other than variety kirikawadi are safer to use as leafy vegetable, because the boiling time is limited in leafy vegetable preparation, poisonous cyanide may not be removed. Considering all the results in this study, variety Kirikawadi contains higher cyanide levels compared to other varieties, both in leaves and root.

Table 1. HCN content in Cassava Roots Table 2. HCN content in Cassava leaves with and without cortex

Variety HCN with cortex (ppm)

HCN without

cortex (ppm)

Variety HCN in Top leaves

(ppm)

HCN in Mature

leaves (ppm) Suranimala 30.58ab 20.11b Suranimala 4.04c 2.20b

Mu 51 26.07bc 24.91b Mu 51 4.23c 1.63b

Kirikawadi 40.08a 41.82a Kirikawadi 30.10a 8.40a

Swarna 19.33bc 19.86b Swarna 19.42b 2.43b

CARI 555 21.61bc 16.17b CARI 555 26.38a 2.67b

Shani 12.92c 21.01b Shani 16.49b 1.93b

HORDI MU1 28.39ab 23.21b HORDI MU1 2.81c 1.44b

CV% 27.39 28.03 CV% 24.52 23.06Means with the same letters are not significantly Means with the same letters are not significantly different at p< 0.05 different at p< 0.05

ConclusionIn eight months old, immature cassava leaves (top bunch to 3rd leaf) contain high

cyanide content while leaves from 4th leaf contain comparatively less cyanide level. Variety Kirikawadi gave the highest cyanide level in immature and mature leaves and roots with and without cortex. The cyanogenic potential is high in variety Kirikawadi both in leaves and in roots. Cyanide levels in root in other varieties was less than 30 ppm. As the cyanide content change with different agronomic traits further studies has to be made for better conclusion.

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References Biology-assets.anu.edu.au. 2019. [online] Available at: http://biology- assets.anu.edu.au/

hosted_sites/ CCDN/protocols/ProtE.pdf (Accessed on 10.05.2019)

Chen, J., L. Liu, M. Li, X. Yu and R. Zhang. 2018. An Improved Method for Determination of Cyanide Content in Bitter Almond Oil. Journal Of Oleo Science. 67(3): 289-294. doi: 10.5650/jos.ess17202

Drochioiu, G., C. Deleanu, E. Rusu and I. Mangalagiu. 2011. Saccharin Reaction with Cyanide. Letters In Organic Chemistry. 8(5): 315-319. doi: 10.2174/157017811795685045

Hidayat, A., N. Zuraida and I. Hanarida. 2016. The Cyanogenic Potential of roots and leaves of ninety nine cassava cultivars. Indonesian Journal of Agricultural Science. 3(1):25.

Imakumbili, M., E. Semu, J. Semoka, A. Abass and G. Mkamilo. 2019. Soil nutrient adequacy for optimal cassava growth, implications on cyanogenic glucoside production: A case of konzo-affected Mtwara region, Tanzania. PLOS ONE,14(5). e0216708. doi: 10.1371/journal.

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Effect of different pre-treatment to break seed dormancy of stored bitter gourd seeds in refrigerated condition

H.M.P.S. Kumari, P.U. Nisansala, E.P. Wijewardhane and D.P. Sumanasinghe

Horticultural Crops Research and Development Institute, Gannoruwa, Sri Lanka

IntroductionBitter gourd is one of the most important vegetables grown in Sri Lanka and

many countries as an edible fruit and for medicinal benefits. Bittergourd fruits are a good source of carbohydrates, proteins, vitamins, and minerals and have the highest nutritive value among cucurbits (Miniraj et al., 1993; Desai and Musmade, 1998). Bitter gourd extracts possess antioxidant, antimicrobial, antiviral, antihepatotoxic and antiulcerogenic properties while also having the ability to lower blood sugar (Welthinda et al., 1986; Raman and Lan, 1996). Seeds are used as planting material for bitter gourd. Though bitter gourd seeds considered as orthodox seeds, rapid germination losses observed with storage with seed deterioration and hard seed coat (Delouche, 1974). Seed deterioration occurs due to lipid peroxidation with lowering germination, delayed emergence and death of the seeds (McDonald, 1999). Hard cutinized testa of some bitter gourd seeds completely prevent imbibition of water and exchange of gases resulting in decrease germination and germination of bitter gourd seed is adversely affect at low temperatures (Fonseka et al., 2011). There is a positive association between lowering germination rate of the seeds with increased biochemical products (Malondialdehyde) and seed dormancy switched on and off at different temperatures (Wang et al., 2003).To overcome this problem seed pretreatment can be practiced and seed priming as hydro-priming with water and osmo-priming solution like KNO3 allows imbibe water and proceed to the first stage of germination (Fonseka et al., 2011). Hydro-priming is a simple technique which can help to increase effectiveness of farm priming. This method has been adopted by many farmers in many countries. Seed priming is also a solution to overcome mechanical restriction on embryo growth by thick seed coat and to overcome bio-chemical restrictions by increasing soluble fatty acids (Mcdonald, 1999). Seed pretreatment resulted in higher germination, earlier seedling emergence, strong growth, lower seed rate requirement and dead seeds and low vigor seeds can be discarded before sowing (Wang et al., 2003). Thinneweli white and Matale green are recommended open pollinated bitter gourd varieties in Sri Lanka. The present study



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was conducted to understand the effect of seed pre-treatments on germination, breaking dormancy and recovery of stored bitter gourd seed samples from Thinnaweli white and Matale green varieties in refrigerated condition.

Materials and methodsThe study was conducted at the Horticultural Crops Research and Development

Institute, Gannoruwa. Two kilos of seeds from each variety produced at HORDI and seeds properly prepared and different seed lots were with above 85% germination and 9% moisture at start to maintain standard storing condition. Seeds stored in refrigerated conditions for six months, one, two and three years were used for this research. Four hundred seeds included in each replicate with Complete Randomized Design (CRD) and they were replicated three times with four seed treatments for germination test. Seed treatments included 24 hour soak in water as a control because that is the normal practice method done by farmers and researchers. Other selected treatments included as hot water treatment at 40 0C for 4 hrs and put in germinating trays, soaking seeds for two hours in vinegar, washed thoroughly and put in germinating trays and two hours in 0.2% KNO3 washed thoroughly and put in germinating trays. Seed germination observed up to three weeks in laboratory condition at room temperature (25-28 0C) according to ISTA (1996) standards and germinated plants established in field to observe growth vigor. Data were analyzed using SAS statistical software version 9.1.

Results and discussionBoth tested varieties showed lowering germination percentage with longer

the time of conservation. Though seed germination depends on many different seed physiological factors, results reveal significantly lower percentage of germination or breaking dormancy with time of conservation compared to 85% initial germination with all the treatments. Tested treatments used for the purpose of soften the hard seed coat of bitter gourd and prevent growth inhibition to facilitate the germination. Hot water treatment and 0.2% KNO3 showed higher percentage of germination with both tested varieties for all four seed lots than other treatments.

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Table 1. Mean seed germination percentage of bitter gourd with different priming treatments

Seed treatment Seed germination %6 months old I year old 2 years old 3 years oldTW MG TW MG TW MG TW MG

Hot water 40 0C for 4 hrs 80a 90a 80a 90a 60bc 75a 30cd 60a

Vinegar 1% (2 hrs) 70b 80b 50bc 80b 30c 60c 10d 55b

KNO3 0.2% (2 hrs) 80a 85ab 80a 80b 60bc 70b 30cd 55b

Control (24 hr soak in water) 70b 75c 50c 60c 30cd 60c 10d 30c

CV % 5.9 9.1 2.62 6.17 3.13 9.48 4.51 11.0Mean in each column followed by the same letters are not significantly different( p=0.05)TW =Thinnaweli White, MG= Matale Green

Results observed with control samples indicated rapid decrease in seed germination with the increase of storage time and that results revealed normal conventional seed soak treatment was not sufficient to break dormancy in some viable seeds. This observation can be explained with bio-chemical reactions of bitter gourd seeds which may affect direct germination with development of secondary dormancy with time of storage according to Wang et al. (2003). The amount of effective chemicals in imbibed primed and hot water soaked seeds may be reduced peroxide scavenging enzymes to help germination of seeds with appropriate temperature at 40 0C.

Both percentage and speed of emergence were observed in higher with hot water treated seeds than control (Table 1). Gradually decreased recovery was observed with both of the tested varieties (Figure 1). Lowering recovery of seeds from their developed seed dormancy may be related with seed deterioration with time of storage (Delouche, 1974).

Figure 1. Seed germination and recovery percentage of TW and MG with time of conservation and pre-treatmentTW =Thinnaweli White, MG= Matale Green

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Rapid germination losses observed with bitter gourd variety Thinnaweli white than Matale green and there may be varietal interaction with related morphological characters. Variety Thinnaweli white showed low recovery percentage and germination losses from 85% to 10% during 3 years (Figure 1). Hot water treatment showed the highest seed germination percentage with both of the tested varieties and that could be the most acceptable method for farmers and researchers. Refrigerated condition may not be applicable for long term conservation of bitter gourd seeds and it is better to go for other optimized conditioned for long term storage. Hot water treatment is the most practical method because it is a low cost method and easy to apply even at farmer level.

ConclusionHot water treatment at 40 0C for 4 hours, and two hours in 0.2% KNO3 treatment

could be considered as better treatment to increase seed germination and seed dormancy of selected varieties (Thinnaweli white and Matale green) can be broken by these two pretreatments to achieve more than 50% recovery. Germination percentages were remarkably decreased with increase in storage time in refrigerated condition for both varieties. Hot water treatment at 40 0C for 4 hours could be considered as a convenient method to apply in research and farmer level with bitter gourd variety Thinnaweli white and Matale Green to overcome low seed germination problem related with seed dormancy.

ReferencesDelouche, J.C. 1974. Maintaining soybean seed quality in soy bean production, Marketing and

Use. NFDC, TVA. Muscle Shoals, Alabama. Bull. 69: 46- 62.

Desai, U.T. and A.M. Musmade. 1998. Pumpkins, squashes and gourds. pp. 273-298. In D.K. Salunkhe and S.S. Kadam (eds.), Handbook of vegetable science and technology: Production, composition. storage and processing. Marcel Dekker, New York.

Fonseka. 2011. Studies on Deterioration and germination of Bitter gourd seed (Momordicacharantis L.) during storage. Proc Vth IS on Seed, Transplant and Stand Establishment of Hort. Crops. 31-38.

McDonald, M.B. 1999. Seed Deterioration: Physiology, repair and assessment. Seed Science Technology. 27:177-237

Miniraj, N., K.P. Prasanna and K.V. Peter. 1993. Bitter gourd Mornordicu app. In: C. Kalloo and 8.0. Bergh (ads.), Genetic improvement of vegetable plants. Pergamon Press, Oxford, UK. 239-246.

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Raman, A. and C. Lau. 1996. Anti-diabetic properties and phytochemistry of Mornoi-dicochorantio L. (Cucurbitaceae). Phytomedicine 2:349-362.

Welihinda, J., E.M. Karunanayake, M.H. Sheriff and K.S. Jayasinghe. 1986. Effect of Momordicochorantia on the glucose tolerance in maturity onset diabetes. J. Ethnopharmacol. 17:277-282.

Wang, H.Y., C.L. Chen and J.M. Sung. 2003. Both warm water soaking and macro conditioning treatments. Enhance anti-oxidation of bitter gourd seeds germinated at sub-optimal temperature Seed Science and Technology. 31(40):241-246.



The effect of meteorological factors on the population dynamics of fruit fly

A.S. Pushpakumari and M.G.N.E. Mahagollage

Fruit Research and Development Institute, Kananwila, Horana, Sri Lanka

IntroductionFruit flies (Bactrocera species, Tephritidae: Diptera) are the most destructive

quarantine pests of fruits in Sri Lanka. They are considered as the major constraint for the production of insecticide residue free quality fruits for local and export market. Most common species attacking fruits are Bactrocera dorsalis, Bactrocera kandiensis, Bactrocera correcta and Bactrocera zonnata. Monitoring of fruit fly population throughout the year or mass trapping of male flies (Male Annihilation Technique) is one of the components of Area-Wide management approach. This pest does not remain static throughout the year, but changes accordingly based on abiotic factors such as temperature, rainfall and relative humidity etc. Therefore it is necessary to have basic information on the incidence of the pest dynamics in relation to weather parameters that is useful for proper implementation of fruit fly management program. The population dynamics of fruit flies have been studied in tropics and have revealed that there is a positive correlation between Methyl eugenol trap catches and meteorological factors such as rainfall and humidity. The number of generations of fruit fly per year also may change with different climatic conditions. Furthermore information obtained from pheromone trap catches in any area can be used for development of models to predict the seasonal incidence of pest. Therefore, this study was aimed to study the influence of weather parameters such as maximum and minimum temperatures, relative humidity and rainfall on fruit fly trap catches in fruit orchards.

Materials and methodsThis study was carried out in fruit orchards with Guava, Citrus, Mango, Rose

Apple, Star fruit and Jack fruit at Fruit Research and Development Institute, Kananwila, during 2016 and 2017. Steiner traps were prepared using transparent plastic bottles of approximately 1 l capacity. One milliliter of Methyl eugenol was applied on cotton swab and suspended in the middle of the bottle. Forty traps were randomly established in different fruit orchards. The fruit fly catches were counted at 2 weeks interval. The cotton swabs were replaced with new ones at the same time. The climate data

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were collected from the meteorological station located at Diyagama. Mean number of fruit flies per trap per day was correlated with weather parameters such as maximum temperature, relative humidity and rainfall. The data were analyzed using statistical package SAS-9.1.

Results and discussionThe results indicated that fruit fly population prevailed throughout the year.

The regression analysis of weather factors and fruit fly catches per trap per day during 2016 showed that abiotic factors such as maximum temperature and rainfall correlated significantly. The model was significant at 0.0046 (less than 5%). R square was high, about 77% which means about 77% of the variation of mean fruit fly count per trap per day is explained by the selected weather factors. Out of the parameters tested (Maximum and minimum temperatures, relative humidity and rainfall) only maximum temperature and rainfall were significant. While maximum temperature is increased by one unit, the mean fruit fly count per trap per day was declined by 1.61 units during 2016 and showed negative correlation (Table 1). The peak fruit fly catch per trap per day (17.9) was recorded at mean monthly maximum temperature 30.7 0C. The highest mean maximum temperature (32.7 0C) was reported during March where the number of fruit flies per trap per day was also very low (1.37). Rajitha and Viraktamath (2006) had also reported a negative correlation of Bactrocera dorsalis population with maximum temperature. While rainfall is increased by one unit the fruit fly count per trap per day is increased by 0.40781 units and showed positive correlation. The peak male fruit fly population coincided with the highest rain fall which was recorded during May. Mahmood et al. (2002) also reported a positive correlation between rainfall and Dacus zonatus trapping in peach orchards in Pakistan.

Table 1. Regression equation between abiotic factors and fruit fly trap countAbiotic Factors Year Regression equation R Square

Maximum temperature and Rainfall

2016 Y=-17.05+(-1.6x30.77)+(0.4x13.8) 0.77

Maximum temperature and Relative Humidity

2017 Y=923.63+(-11.52x30.65)+(-5.51x85.5) 0.74

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Figure 1. Effect of weather factors on fruit fly population during 2016

During 2017 also the model was significant at 0.007 and the adjusted R square was 0.74 (74%). Out of the weather parameters tested both maximum temperature and relative humidity showed negative correlations with fruit fly trap counts. When maximum temperature and RH are increased by one unit, fruit fly trap count declined by 11.52 units and 5.51 units respectively. Suitable regression equations for prediction of fruit fly population for 2016 and 2017 are shown in Table 1. Similar result of correlation between relative humidity and fruit fly catch was also observed by several workers (Shukla and Prasad,1985).

Figure 2. Effect of weather factors on fruit fly population during 2017

When compared to 2016 the negative effect of mean maximum temperature on fruit fly catch per trap per day was higher in 2017. The highest maximum temperatures in 2016 and 2017 were 32.7 0C in March and 32 0C in February respectively. There were two peaks of fruit fly catch per trap per day during June and September in 2017 (Figure 2). However, the fruit fly population decreased during 2017 compared to 2016.

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ConclusionAbiotic factors; maximum temperature, rainfall and relative humidity contribute

significantly toward increasing or decreasing male fruit fly trapped in to methyl eugenol traps. This study supports to determine the peak periods of fruit fly population and to decide management strategies.

ReferencesMahmood, T., S.I. Hussain, K.M. Khokhar, M. Ahmad and Hidayatullah. 2002. Studies on

methyl eugenol as a sex attractant for fruit fly, Dacus zonatus (Saund) in relation to abiotic factors in peach orchard. Asian Journal of Plant Sciences. 4: 401-402.

Rajitha, A.R. and S. Viraktamath. 2006. Monitoring fruit flies(Diptera:Tephritidae) in guava orchard in Dharwad, Karnataka. Karnataka Journal of Agricultural Science. 19: 35-39.

Shukla, R.P. and V.G. Prasad. 1985. Population fluctuation of the oriental fruit fly, Dacus dorsalis Hendel in relation to host and abiotic factors. Tropical Pest Management, 31: 273-275.

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Management of chilli thrips (Scirtothrips dorsalis) through application of calcium phosphate solution

S. Rajeshkanna, S. Mugunthini and R. Jathukula

Regional Agricultural Research and Development Centre, Kilinochchi, Sri Lanka

IntroductionChilli is a major cash crop grown in Sri Lanka for both green and dry chilli

production. The per capita dry chilli consumption of Sri Lanka is about 2.84 kg with the total national requirement per year is around 57,400 mt (DOA Sri Lanka, 2018).

Occurence of pests and diseases are the major constrains in chilli production in Sri Lanka. The chilli thrips, mites, whiteflies and aphids are the major causal agents to chilli leaf curl complex (Senanayake et al., 2013). Some viruses transmitted by whitefly and aphids to the chilli plant result severe Chilli Leaf Curl Complex (CLCC) (Weeraratna and Yapa, 2002). Bacterial wilt and fungal diseases such as Anthracnose and Cercospora leaf spot also cause a significant yield loss (Galanihe et al., 2004). Chilli crop has also affected by Meloidogyne incognita and Meladogyne javanica formed knots in roots and reduced the plant growth and damaged the yield in Matara district (Premachchandra et al., 2007).

Chilli growers in Sri Lanka mainly depend on pesticides to control insect pests and fungus diseases of chilli cultivation. Use of agro chemicals above recommended rates destroy the beneficial organisms which in turn increases pests infestation (Atakan, 2006). Therefore, farmers need alternative ways to manage pest and diseases instead of chemical control where bio-fertilizers can play a major role.

Green chilli, Garlic and Ginger (3G) solution is one of the bio pesticide which can help to reduce most of the foliage pests on various crops. However this product is not readily available for farmers' use.

It has also been found that, the hatch rate, feeding and oviposition of onion thrips were reduced on onion leaves treated with a kaolin based particle film (Larentzaki et al., 2008). Therefore, this study was conducted with same concept to manage the chilli thrips by using locally available material (Calcium phosphate) to form particle film on the leaf surface.



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Materials and methodologyThis experiment was conducted in Yala 2018 at RARDC, Kilinochchi. The

experiment field was prepared by ploughing twice with a disc and followed by planking to ensure a good soil tilth. Five treatments (Table 1) were laid in a Randomized Complete Block Design (RCBD) with three replicates. Chilli seedlings were planted at 60 cm x 60 cm spacing in plots having 4 m x 3 m dimension. Two seedlings were planted in each hill. Fertilizer was applied at recommended levels. Calcium phosphate surfactant were used as materials to prepare the solution. Calcium phosphate solution was sprayed once a fortnight since seedlings to harvesting stage. The knapsack sprayer was used to apply the solution on plants canopy. The initial application was done at two weeks after planting. The solution was sprayed immediately after preparation. Three plants per plot were selected randomly to count the population of thrips. Three leaves were selected as one from each top, middle and bottom part of the selected plants. The population count of the thrips was recorded on the following day after each application of calcium phosphate solution. The data obtained from the study were analyzed using SAS 9.1 statistical software. The least significant different was calculated following a Duncan’s Multiple Range Test (at p<0.05).

Table 1. The treatments of the experimentsTreatment number Dilution dosage

1 1 g Calcium phosphate/1l of water2 2 gCalcium phosphate /1l of water3 5 g Calcium phosphate /1l of water4 10 g Calcium phosphate/1l of water5 Untreated control

Results and discussionTable 2 shows the effectiveness of various treatments on the thrips population

on chilli plants after 24 hours of treatments and final yield of green chilli. The different dilution of calcium phosphate solutions caused reduction of population of chilli thrips after each treatment. The treatment with 10 g of calcium phosphate solution significantly controlled thrips compared to other four treatments. While there was an apparent reduction of pest population in T3, T2 and T1 also.

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Table 2. Means population of thrips and average yield of green chilli.Treatment Thrips number/leaf Yield (t/ha)

1 g Calcium phosphate /1l of water 13b 25.6d

2 gCalcium phosphate /1l of water 13b 29.3c

5 g Calcium phosphate /1l of water 10b 38.9b

10 g Calcium phosphate /1l of water 5c 60.9a

Untreated control 20 a 18.5e

CV 18.9 5.3LSD 4.3 3.4

An increase in concentration of Calcium phosphate solution reduced the number of thrips on chilli leaf (Table 1) and increased the yield of green chilli. This may be because the foliar applications of calcium phosphate on chilli plants may have caused the accumulation of calcium phosphate particle on the leaf surface and thereby forming a mechanical barrier on the plant leaf surface.

ConclusionThe results of the study show that the application of Calcium phosphate solution

significantly reduces the thrips population in chilli resulting higher yield compared to control. Calcium phosphate solution with 10 g/l of water is the most effective mixture ration among with the treatments tested.

ReferencesAtakan, E., 2006, Associations between Frankliniella spp. and Orius niger populations in

cotton, Phytoparasitica. 34. 221–234.

DOA. 2018. chilli, https://www.doa.gov.lk/fcrdi/index.php/en/crop/34-chilli, (Accessed on 12.05.2019).

Galanihe, L.D., M.G. Priyantha, D.R. Yapa, H.M.S. Bandara and J.A.D. Ranasinghe. 2004. Insect pest and disease incidences of exotic hybrid varieties grown in the low country dry zone of Sri lanka, Annals of the Sri Lanka Department of Agriculture. 6: 275-280.

Larentzaki E., A.M. Shelton and J. Plate. 2008. Effect of kaolin particle film on Thrips tabaci (Thysanoptera: Thripidae), oviposition, feeding and development on onions: a lab and field case study. Crop Protection 27: 727–734.

Premachandra, W.T.S.D., A.H.P. Lasanthi, K.H.M.A. Deepananda and R.C. Jayasinghe. 2007. Infestations of root-knot nematodes, Meloidogyne species, associated with selected vegetables crop in Matara district in Sri Lanka, Proceeding of the fourth academic sessions. 159-163.

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Senanayake, D.M.J.B., J.E.A.R.M. Jayasinghe, S. Shilpi, S.K. Wasala and B. Mandal. 2013. A new bigamo virus – betasatellite complex is associated with chilli leaf curl disease in Sri Lanka, Journal of Virus Genes, 46. 128 – 139.

Weerarathne, W.A.P.G. and D.R. Yapa. 2002. Reaction of chilli accessions to local isolates of cucumber mosaic and chilli mottle viruses. Annals of the Sri Lanka Department of Agriculture. 4: 345-352.

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Effect of chloromaquat chloride 50% SL. application on growth and yield of capsicum (Capsicum annum L.)

K.A.D.S.D. Kahandawaarachchi, B.M.A.U.K. Bandara and A.R. Jayasena

Horticultural Crops Research and Development Institute, Gannoruwa, Peradeniya, Sri Lanka

IntroductionCapsicum (Capsicum annum L.) is a tropical plant which belongs to family

solanaceae and ideally suited to hot and humid conditions. In Sri Lanka, capsicum is one of the popular vegetables in most of the dishes. In 2017, about 26,952 mt of capsicum was produced in Sri Lanka from 3,208 ha in both Yala and Maha seasons (AgStat, 2018). Even though the demand of capsicum is high in Sri Lanka, the production of capsicum is low due to pest and diseases, poor post-harvest handling and unfavorable environmental conditions such as irradic rainfall, extreme temperatures and high relative humidity. Flower and fruit drop also a reason for yield reduction caused by physiological and hormonal imbalance in the plants particularly under unfavorable environments such as extremes of temperature (Erickson and Markhart, 2001). The flower and fruit drop may be reduced to some extent by spraying various growth regulators on foliage (Ramesh and Thirumuguran, 2001).

Nowadays, the plant growth regulators play a significant role in the agriculture sector. Plant growth regulators (PGRs) are chemicals that are designed to affect plant growth and development and are applied for specific purposes to bring about specific plant responses. The PGRs are also known to enhance the source sink relationship and stimulate the translocation of photosynthetic assimilates, thereby increasing the productivity of plants (Taiz and Zeiger, 2003).

Chloromaquat chloride is one of the growth regulator used in agriculture sector. It is an anti-gibberellin growth retardant (Singh et al., 2000) that inhibits both cell division and cell elongation (Bode and Wild, 1984). Chloromaquat chloride is used to promote lateral branching and flowering in azaleas, fuchsias, begonias, poinsettias, geraniums, pelargoniums and other ornamental plants to promote flower formation and improve fruit setting in pears, almonds, vines, olives and tomatoes and to prevent premature fruit drop in pears, apricots and plums. It is also used on cotton, vegetables, tobacco, sugarcane, mangoes and other crops to improve the yield.



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Chloromaquat chloride is commercially available in Sri Lanka in different concentrations. Most of them are introduced for different crops including vegetables which are applied at different time periods. The optimum Chloromaquat chloride rate and frequency of application will vary depending on the crop. But the rate of application and the time of application are not yet studied. Sometimes unwanted, excessive applications are time and money wasting practices adopted by farmers. Therefore, it is important to find the effect of chloromaquat chloride on different vegetables and to find the rate of application and the time of application to minimize the losses incurred by farmers.This study was aimed to find the effect of Chloromaquat chloride application on growth and yield of capsicum grown in open field.

Materials and methodsThe experiment was conducted at Horticultural Crops Research and

Development Institute (HORDI), Gannoruwa from October 2015 to February 2016 (Maha 2015/16) and from May 2016 to September 2016 (Yala 2016). The site locates at an elevation of 500-1000 m from Mean Sea Level, belongs to WM 2b (Mid Country Wet zone) and consists of Red Yellow Podzolic Soil. Capsicum variety CA8 was used as the test crop for this experiment. Chloromaquat chloride was sprayed as a foliar spray at different growth stages of capsicum plants at the rate of 10 ppm. As treatments, water was sprayed as the control treatment (T1). Chloromaquat chloride was sprayed at one week after transplanting (T2), two weeks after transplanting (T3), five weeks after transplanting (T4) and one, two and five weeks after transplanting (T5).

Standard cultural practices recommended by Department of Agriculture were adopted in raising Capsicum plants. Plants were spaced at 40 cm x 40 cm and basal fertilizer together with cattle manure was applied in each hole two days prior to planting.

Treatments were arranged in Randomized Complete Block Design (RCBD) with three replicates. Three weeks aged healthy seedlings were transplanted in prepared hills in each plot and they were irrigated daily and manual weeding was practiced. Fertilizer was applied based on the department recommendation and Chloromaquat chloride was sprayed according to the treatment.

Growth parameters, such as plant height was recorded at two weeks intervals. Leaf chlorophyll content was measured using a Chlorophyll meter (SPAD 502) at two weeks interval. Crop yield was measured at each harvest and cumulative yield was used for statistical analysis.

86

Analysis of variances were done using SAS Statistical software package version 9.1 and means were separated by Duncan’s Multiple Range Test at 5% probability level.

Results and discussionGrowth parametersMean plant height of the crop

Mean plant height of the crop was not significantly different among treatments up to four weeks after transplanting (WAT).

Table 1. Mean plant height during the growth stage of Capsicum (2016c)Treatment 2WAT (cm) 4WAT (cm) 6WAT (cm) 8WAT (cm)

Control 10.90a 18.20a 30.26a 38.60a

Spray at 1WAT 11.83a 17.23a 27.76ab 33.10b

Spray at 2WAT 11.06a 16.60a 26.60ab 31.93b

Spray at 5WAT 11.10a 17.26a 25.60b 33.73b

Spray at 1,2 & 5WAT

12.15a 17.90a 28.20ab 32.50b

CV% 14.80 9.76 7.57 6.70Means followed by the same letter along columns for each treatment was not significantly different at 5% probability level

Significantly low plant height was recorded in treatment 5 where Chloromaquat chloride was applied at 5WAT (flowering stage), however at 8 WAT, the untreated control recorded a significantly higher plant height compared to all other treated plants. This is an agreement with Singh et al. (2000) who has reported a retarded plant growth with the application of Chloromaquat chloride.

Leaf chlorophyll content during the growth stage of the cropThere was no significant difference observed among treatments in chlorophyll

content during the growth of the crop.

Table 2. Chlorophyll content (µ mol/cm2) during the growth stage of Capsicum (Yala 2016)Treatment Chlorophyll content (µ mol/cm2)

At 2ndWAT At 4thWAT At 6thWAT At 8thWATControl 35.90a 38.33a 41.03a 42.43a

Spray at 1WAT 38.20a 44.66a 43.96a 45.30a

Spray at 2WAT 33.86a 39.66a 41.43a 43.76a

Spray at 5WAT 33.96a 41.13a 42.96a 41.36a

Spray at 1,2 & 5WAT 39.05a 38.65a 38.70a 42.15a


Kahandawaarachchi et al.

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Yield parametersAverage fruit length, width and thickness of fruits

Average fruit length and fruit thickness had not shown any significant difference among treatments. However, significantly higher average fruit width has been recorded in untreated control at 2nd harvest.

Table 3. Average fruit length, width and fruit thickness (Yala 2016)Treatment Average fruit length

(cm)Average fruit width

(cm)Average fruit

thickness (mm)At 2nd

harvestAt 3rd

harvestAt 2nd

harvestAt 3rd

harvestAt 2nd

harvestAt 3rd

harvestControl 10.20a 10.03a 1.73a 1.76a 1.63a 1.71a

Spray at 1WAT 9.40ab 9.46a 1.70ab 1.63b 1.77a 1.79a

Spray at 2WAT 9.16ab 8.60a 1.63bc 1.63b 1.62a 1.64a

Spray at 5WAT 8.46b 8.16a 1.63bc 1.60b 1.52a 1.89a

Spray at 1,2 & 5WAT

9.60ab 10.00a 1.60c 1.65b 1.55a 1.62a

CV% 7.36 9.72 2.47 3.39 12.50 7.92Means followed by the same letter along columns for each treatment was not significantly different at 5% probability level

Fruit yield of CapsicumSignificantly higher number of fruits (20/plant) was recorded by the control

than the Chloromaquat chloride applied treatments. It was the lowest in Chloromaquat chloride sprayed at two weeks after transplanting. However, single fruit weight was not significantly different among tested treatments.

Table 4. Fruit yield/plant and total yield of capsicum (Yala 2016)Treatment No. of fruits/

plantSingle fruit weight (g)

Fruit yield/plant (g)

Total yield (tons/ha)

Control 20.10a 15.52a 312.17a 19.50a

Spray at 1WAT 16.52bc 15.61a 257.83bc 16.11bc

Spray at 2WAT 16.05c 14.82a 237.17c 14.81c

Spray at 5WAT 17.91b 14.99a 269.00b 16.81b

Spray at 1,2 & 5WAT

17.73b 14.98a 266.00b 16.62b


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Among the tested treatments, the significantly highest fruit yield per plant and the total fruit yield (t/ha) were recorded by the control than Chloromaquat chloride sprayed treatments. Total fruit yield was significantly low compared to all other treatments when Chloromaquat chloride was applied at 2WAT. Similar results have been observed 2015/16 Maha and Yala seasons.

ConclusionIncreasing yield is the essential requirement in commercial production of

Capsicum. All the tested treatments (applying Chloromaquat chloride 50% SL at the rate of 10 ppm at different stages of the crop) had no significant effect on increasing the growth and yield performances of capsicum.

ReferencesAgStat. 2018. Socio Economics and Planning Centre, Department of Agriculture, Peradeniya,

Sri Lanka. Volume XV:33.

Bode, J. and A. Wild. 1984. The influence of 2-Chloroethyl trimethyl ammonium chloride (CCC) on growth and photosynthetic metabolism of young wheat plants (Triticum aestivum L.) Journal of plant physiology 116 (5): 435-446.

Erickson, A. and A. Markhart. 2001. Flower production, fruit set and physiology of bell pepper during elevated temperature and vapor pressure deficit. Journal of American Society in Horticultural Science 126 (6): 697-702.

Ramesh, K. and V. Thirumurugan. 2001. Effect of seed pelleting and foliar nutrition on growth of soybean. Madras Agriculture Journal 88 (7/9): 465-468.

Singh, P., N.K. Srivastava, A. Mishra, and S. Sharma. 2000. Influence of ethral and gibberellic acid on carbon metabolism, growth and essential oil accumulation in Spearmint (Mentha spicata). Photosynthetica 36 (4): 509-517.

Taiz, L. and E. Zeiger. 2003. Auxin-the growth hormone. Plant Physiology. In: Panima Publishing Corporation, New Delhi. 423-456.

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Re-evaluation of the recommended spray volume to control brown plant hopper (Nilaparvata lugens Stål) at outbreak

situation using ethiprole 100 g/l SC and Thiocyclam hydrogen oxalate 50% SP

S.R. Sarathchandra1, J.H.T.G. Kavindya1,2, A. Mannakkara2, M.A.B.R.P. Bandaranayake1, P.G.K. Perera1 and A.G.N.H. Madhuvanthi1

1Rice Research and Development Institute, Batalagoda, Sri Lanka2Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka

IntroductionRice (Oryza sativa L.) is the second most important cereal crop in the world

and dietary staple crop for more than half of the world’s population (Muthayya et al., 2014). Presently, there are many problems associated with paddy cultivation, which accounts for yield reduction. Insect pests are serious constrains to increase rice yield and cause significant damage to the rice production annually. The Brown Plant Hopper (BPH) is one of the most serious economically important rice pests in Sri Lanka. BPH problem has being reported since 1960s (Otake and Hokyo, 1976) and annually BPH damage leads to a loss of about 5-10% of national rice production with the occurrence of several epidemics at regular intervals causing high yield losses (Nugaliyadda et al., 2001; Madurangi et al., 2011). Biological, chemical and physical controlling measures have been used to prevent the BPH infestation. Currently, the application of pesticides is considered as main method for controlling BPH at outbreak situation (Tanaka et al., 2000)

It was observed that there were severe BPH infestation during consecutive seasons of Maha 2017/18, Yala 2018, Maha 2018/19 and Yala 2019 seasons in Kurunegala, Gampaha and Anuradhapura districts. The reason behind such kind of severe BPH attack was found as some failures occurred during the application of BPH controlling measures practiced by farmers. It is suspected that the application of insufficient spray volumes under chemical controlling of BPH at outbreak level is one of the major reasons for continual occurrence of BPH outbreaks.

The common recommendation for spray volume/ha of any insecticide given by Department of Agriculture for top canopy is 25 tanks/ha. Even though, the recommended spray volume (25 tanks/ha) gives best results for other pests found in rice fields and



90 Sarathchandra et al.

necessary to re-evaluate the spray volume for BPH control at outbreak level due to the requirement of both top canopy and basal area application. Therefore, this study was conducted with the objective of finding the most appropriate spray volume per hectare by re-evaluating the recommended spray volumes using already recommended two chemicals for BPH management. Findings of this study will help to manage the BPH out breaks in most successful way without allowing a severe BPH damage to the rice cultivations in Sri Lanka.

Materials and methodsThe experiment was conducted at a farmer field located in Barandana,

Ibbagamuwa, which is nearby Rice Research and Development Institute, Batalagoda. The suitable spray volume (relevant to 16 l spray tank) was checked using 5 treatments with 3 replicates in a Randomized Complete Block Design (RCBD). Field was divided into 15 plots each having 100 m2 area and as the treatments, 25 tanks/ha (T1), 30 tanks/ha (T2), 35 tanks/ha (T3), 40 tanks/ha (T4) and untreated control (T5) were used. The plots were treated with different spray volumes of Ethiprole 100 g/1 SC and Thiocyclam Hydrogen oxalate 50% SP insecticides which are used for BPH controlling and applied according to the area of plots (100 m2). Before treatment applications, pre-counts of BPH were obtained from 15 randomly selected plants in each plot. Number of BPH remained after the application of each treatment was counted after 3 days and 5 days post treatments. Abbott’s formula (Equation 1) was used to calculate the population reduction over control as a percentage (Fleming and Ratnakaran, 1985). This formula is applied to entomological field data to distinguish the effects of pesticide treatment from those caused by natural factors. Results were analyzed using SAS statistical package version 9.1.

1- ( Post treatment population in treatmentx

Pre treatment population in control )Pre treatment population in treatment Post treatment population in control

91

Results and discussionTable 1. Number of BPH (adults and nymphs) in 15 plants (average 3 replicates) in plots treated with Ethiprole 100 g/l SC and in untreated control and population reduction over control (%).

Treatment Application rate ml/ha (Dilution

15 ml/10 l)

No of BPH (adults and nymphs/ 15 plants)

Population reduction over

control (%)Before treatment

3days after treatment

5days after treatment

25 tank/ ha 600 327.17a 223.44b 175.73b 35.1930 tank/ ha 720 327.22a 202.97c 93.24c 48.7035 tank/ ha 840 327.17a 33.37d 12.77d 98.2040 tank/ ha 960 327.28a 20.66e 13.46d 95Untreated control - 327.46a 324.13a 323.88a 0CV% 1.01 2.34 24.87

Means followed by the different letters in the same column represent significant difference at 5% level by Least Significant Different Test

Table 2. Number of BPH (adults and nymphs) in 15 plants (average 3 replicates) in plots treated with Thiocyclam Hydrogen Oxalate 50% SP and in untreated control and population reduction over control (%).

Treatment Application rate g/ha (Dilution 25 g/10l)

No of BPH (adults and nymphs/ 15 plants)

Population reduction

over control (%)

Before treatment

3 days after treatment

5 days after treatment

25 tanks/ ha 1000 335.37a 201.63b 124.37b 62.4030 tanks/ ha 1200 336.10a 172.56c 55.23c 71.5035 tanks/ ha 1400 350.50a 143.06d 15.53d 79.4040 tanks/ ha 1600 324.90a 70.03e 2.97d 89.50Untreated control - 320.57a 408.56a 521.87a 0CV% 5.88 2.46 10.29

Means followed by the different letters in the same column represent significance different at 5% level by Least Significant Different Test

It was observed that the plants treated with 30 tank/ha, 35 tank/ha and 40 tank/ha and recommended 25 tank/ha did not have any significantly different means of populations compared to untreated control before the treatment application. After 3 days of treatment application there was a significant difference between the means of BPH populations in treated plots and untreated control. As well as 5 days after application, there was a significant difference between the means of BPH populations in treated plots and untreated control, among them highest population reduction was given by 35 tank/ha and 40 tank/ha treatments, however there was no any significant difference between means of BPH populations for above two treatments (Table 1 and 2).

92 Sarathchandra et al.

Figure 1. Population reduction percentage (%) over control with the treatments in plots treated with Ethiprole 100 g/l SC the data represented means SD

Figure 2. Population reduction percentage (%) over control with the treatments in plots treated with Thiocyclam hydrogen oxalate the data represented means SD

Above graphs in Figure 1 shows that the BPH population reduction % over untreated control with respect to the each treatment. According to the graphs, it clearly indicates that sprays volume of 35 tanks/ha gave the highest BPH reduction value than others. Meanwhile, Figure 2 shows that the population reduction percentage was gradually increased from the standard spray volume (25 tanks/ha) to the 40 tanks/ha.

According to the results given by this study, spray volume of 35-40 tanks/ha can be taken as the efficient spray volume instead of the common insecticide spray volume recommendation for manage the BPH at the outbreak conditions in rice fields. Since, this spray volume was efficient than the recommended spray volume (25 tanks/ha) to apply both top canopy and basal area of the infested rice plants, it can be used to manage the BPH outbreaks successfully.

Conclusion Recommended spray volume is not efficient for BPH control when there is

an outbreak. Usage of spray volume higher than 35 tanks/ha is effective and cause significant reduction of BPH. However, it is not an economically feasible option for Sri Lankan farmers to use as a BPH outbreak management option.

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ReferencesFleming, R. and A. Ratnakaran. 1985. Evaluating single treatment data using Abbott’s formula

with reference to insecticides. Journal of Economic Entomology. 78(6):1179-1181.

Madurangi, S.A.P., W.L.G. Samarasinghe, S.G.J.N. Senanayake, P.V. Hemachandra and D. Ratnasekera. 2011. Resistance of Oryza nivara and Oryza eichingeri derived lines to brown planthopper, Nilaparvata lugens (Stal). Journal of the National Science Foundation of Sri Lanka. 39(2).

Muthayya, S., J.D. Sugimoto, S. Montgomery and G.F. Maberly. 2014. An overview of global rice production, supply, trade, and consumption. Annals of the new york Academy of Sciences. 1324(1):7-14.

Nugaliyadda, L., A.A. Amarasinghe and T. Hidaka. 2001. The rice brown plant hopper outbreak in Maha1997/1998 season. Strategies to improve rice pest management in Sri Lanka. Annals of the Sri Lanka Department of Agriculture. 185-194.

Otake, A. and N. Hokyo. 1976. Rice plant-and leafhopper incidence in Malaysia and Indonesia-report of a research tour January to March 1976. Rice plant-and leafhopper incidence in Malaysia and Indonesia-report of a research tour January to March 1976. (33).

Tanaka, K. and M. Matsumura. 2000. Development of virulence to resistant rice varieties in the brown plant hopper, Nilaparvata lugens (Homoptera: Delphacidae), immigrating into Japan. Applied Entomology and Zoology, 35(4):529-533.

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Profitability analysis of paddy farming in Sri Lanka

N.L. Sudheera1 and B.G.C.A. Gamlath2

1Socio Economics and Planning Centre, Peradeniya, Sri Lanka2Rice Research and Development Institute, Bathalagoda, Sri Lanka

IntroductionThe paddy sector occupies a prominent place in the economy of Sri Lanka.

Even though growing of rice contributed to 0.7% to the GDP in 2018 (Central bank, 2018) most of rural farm families are directly engaged in paddy farming. Sri Lanka has 922,151 ha of paddy land of which 55%, 25%, and 20% are under major, minor irrigation and rainfed conditions, respectively, accounting an annual cropping intensity of 140% (AgStat, 2018). The rice farming has been heavily affected by the rapid increase in cost of production and low farm gate prices. Presently, unit cost of production of paddy is Rs. 23.42 under irrigation condition and Rs. 40.28 rain fed condition (Cost of cultivation Maha 2016/17). In spite of having improved rice varieties and associated technologies capable of yielding around 8-11 t/ha, (Potential Yield) annual average rice yields under major, minor and rain-fed conditions remain at 4.8, 3.8 and 2.9 t/ha, respectively resulting in an overall national average of 4.43 t/ha. This indicates that there is a yield gap between potential average paddy yield and actual paddy yield. It is important to focus on analyzing regional differences of profitability in major paddy growing areas in Sri Lanka.

Materials and methodsThis study used cost of production data, which was published by the Department

of Agriculture twice a year namely Maha and Yala seasons. Time series data from 2005 to 2015 were collected for several districts, which belonged to irrigation and rainfed conditions. Paddy statistics data which were published by the Department of Census and Statistic Sri Lanka were used in the analysis. To remove the inflation, year 2005 took as a base year and used Colombo price index. Secondary data of ten different districts in Sri Lanka were used in the analysis. Hambanthota, Polonnaruwa, Kurunegala (Dry zone), Anuradhapura, Ampara East, and System C under major irrigation water regime and Kurunegala, Gampaha, Kandy, and Kaluthara (Wet zone) under rainfed. Theoretically, the cost is divided into two parts which are fixed cost and variable cost.

Total variable cost = Input cost + Machinery cost + Labor cost



95

Descriptive statistical analysis was applied to examine the cost of production, yield and profit level. The one-way analysis of variance (ANOVA) was used to determine whether the difference of mean of total cost, and mean of net income.

Results and discussionTotal costTable 1. Total mean cost of paddy cultivation Major paddy growing areas in Sri Lanka during Maha 2005 to 2015

Growing area Mean (Rs/ac) St Dev 95% CIAmpara East 31,176 6,111 (26552, 35801)Anuradhapura 33,341 8,047 (28716, 37965)Kurunegala Dry 32,891 8,690 (28267, 37516)Polonnaruwa 32,885 7,676 (28260, 37509)System C 31,398 7,400 (26774, 36023)Hambantota 34,654 8,441 (30029, 39278)Kandy 35,580 8,284 (30955, 40205)Kurunagala wet 29,469 6,669 (24844, 34093)Kaluthara 31,903 8,873 (27278, 36528)Gampaha 32,444 6,580 (27819, 37068)

* St dev = Standard Deviation CI = Confidence Interval

Table 2. Total mean cost of paddy cultivation Major paddy growing areas in Sri Lanka during Yala 2005 to 2015

Growing area Mean (Rs/ac) St Dev 95% CIAmpara East 32,169 5,378 (27733, 36606)Anuradhapura 33,870 7,429 (29434, 38307)Kurunegala Dry 32,257 8,962 (27821, 36694)Polonnaruwa 34,308 7,290 (29872, 38745)System C 32,270 7,614 (27834, 36707)Hambantota 35,316 7,289 (30879, 39752)Kandy 35,580 8,284 (31143, 40017)Kurunagala wet 31,222 6,710 (26786, 35659)Kaluthara 33,362 8,481 (28925, 37798)Gampaha 32,780 5,984 (28343, 37216)

* St dev = Standard Deviation CI = Confidence Interval

The result of the one way ANOVA test showed that Mean of total cost in each district in Maha and Yala seasons during 2005 to 2015 time period in the study area was not statistically significant (p=0.823 and p=0.925) at the α = 0.05 significant level. (Table 1 and Table 2)

96 Sudheera et al.

Net incomeTable 3. Mean Real Net income of paddy cultivation Major paddy growing areas in Sri Lanka during Maha 2005 to 2015 seasons

Growing area Mean (Rs/ac) St Dev 95% CIAmpara East 8948 1267 (8277, 9619)Anuradhapura 6214 1058 (5543, 6886)Kurunegala Dry 5819 1126 (5148, 6490)Polonnaruwa 6076 816 (5405, 6748)System C 6247 1079 (5576, 6918)Hambantota 7471 1512 (6800, 8142)Kandy 4397 1128 (3726, 5068)Kurunagala wet 5710 1040 (5039, 6381)Kaluthara 4991 1002 (4320, 5662)Gampaha 5689 1058 (5018, 6360)

Table 4. Mean Net income of paddy cultivation Major paddy growing areas in Sri Lanka during Yala 2005 to 2015

Growing area Mean (Rs/ac) St Dev 95% CIAmpara East 9117 1192 (8477, 9758)Anuradhapura 6537 1027 (5897, 7178)Kurunegala Dry 5752 991 (5111, 6392)Polonnaruwa 6175 890 (5535, 6816)System C 5983 848 (5343, 6624)Hambantota 7268 1282 (6627, 7908)Kandy 4397 1128 (3757, 5038)Kurunegala wet 5829 995 (5188, 6469)Kaluthara 5130 1073 (4489, 5771)Gampaha 6250 1201 (5609, 6890)

The result of the Mean separation of one way ANOVA test given that Mean of Net income in each district in Maha and Yala seasons during 2005 to 2015 time period in all the districts in the study area was statistically significant (p =0.000) at the α = 0.05 significant level (Table 3 and Table 4). Average yield was higher in irrigated area due to higher net income in location.

Paddy farming was more profitable in tested irrigated location compare to the rain-fed locations.The areas that come under low potential area mainly rain-fed districts, where paddy yields constrained by production instability causes such as flood, water logging and inherent infertility of soil. To improve net profit it is essential to develop stress resistant varieties to improve the yield stability in long run.

97

ConclusionThe result shows the differences of total cost of production of paddy cultivation

all the study area during 2005 to 2015 time period, which was not statistically significant

This study that the reals that the value of profitability in districts under rainfed condition is lower than that of the irrigated condition paddy farming in Sri Lanka. In the last ten years, average yield of paddy was low and due to that net income was very low. Paddy farming under rain fed condition is not economically profitable.

ReferencesAgstat. 2018. Cost of cultivation of agricultural crops. Agricultural economics study. Socio

Economic and Planning Centre, Department of Agriculture. 46-80.

Central Bank of Sri Lanka. 2018. Annual Report 2018. [online]. https://www.cbsl.gov.lk/en/publications/economic-and-financial-reports/annual-reports/annual-report-2018.

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Effect of aphids and whiteflies infestation on potato yield in Up Country Wet zone of Sri Lanka

H.A.S.N. Hettiarachchi, M.M. Kumarage and K.M.C.R.K. Bandara

Agriculture Research Station, Sita Eliya, Nuwara Eliya, Sri Lanka

IntroductionPotato (Solanum tuberrosum L.) is one of the most important and extensively

grown crops in Nuwara Eliya and Badulla districts of Sri Lanka. High cost of production is identified as one of the major constrains in the potato value chain. Avoiding use of unnecessary insecticides is therefore, identified as a key strategy in reduction of cost of production. Aphids and whiteflies act as minor pests of potato particularly in Nuwara Eliya region. According to a survey conducted within the Agriculture Instructor range in Nuwara Eliya during 2017, it was revealed that 66% of potato growing farmers rely heavily on insecticides in controlling aphids and whiteflies (Seasonal Report, 2017). In response to this, the efforts were made for evaluating the effect of use of insecticides to control aphids and whiteflies of potato under Up Country Wet zone climatic conditions.

Materials and methodsField experiment was carried out at the Agriculture Research Station (ARS),

Sita Eliya during Maha 2016/17, Yala 2017, Maha 2017/18 and Yala 2018. Uniformly sprouted potatos (variety - Granola) with 3-4 sprouts were planted in plots (6 m2) at the spacing of 60 x 25 cm (contained 40 plants). Crop planting and maintenance were done according to recommended agronomic practices of Department of Agriculture (DOA), Sri Lanka. Three treatments were arranged in a Randomized Complete Block Design (RCBD) with four replicates. Treatments were (T1) - Thocyclam hydrogen oxalate 50% SP and Imidacloprid 200 g/l SL sprayed at recommended dosages once a week alternatively (6 applications/ Season) and (T2) - Thocyclam hydrogen oxalate 50% SP and Imidacloprid 200 g/l SL bi-week alternatively (3 applications/ Seasons) to manage aphids and whiteflies. (T3) - untreated control. Application of insecticide was started at 5 Weeks After Planting (WAP) and continued up to 10 WAP. Number of aphids and whiteflies were recorded in weekly intervals throughout the season from 8 randomly selected plants and harvesting was carried out at the stage of physiological maturity i.e. 105 days after planting and total yield/plot was recorded. All plots were protected from diseases and other pests. Data were analyzed using analysis of variance (ANOVA) with SAS statistical package version 9.1 and mean separation was performed using Duncan Multiple Range Test at p<0.05.



99

Results and discussionAphid and whitefly populations

Development of aphids and whiteflies population was observed from 5 to 12 weeks. In comparison to the Yala 2017, lower number of aphids and whiteflies were reported during Maha 2016/17, Maha 2017/18 and Yala 2018 in unprotected plots and this may be due to the variation in climatic factors within the four seasons (Figure 1). The rise of aphids and whiteflies populations could be attributed by the relative low rainfall and low relative humidity (RH) prevailed during Yala 2017 season (Figure 2, A and B). Kelm et al. (2009) also reported that weather was the factor, which mostly determines the population buildup of aphid number in potato crops. Also whitefly is one of the most economically important pests in warmer climatic condition and negative correlation was reported between whitefly population and weather parameters on potato (Jha and Kumar, 2018). According to the survey conducted by ARS, Sita Eliya during 2006/2007 period, potato fields in Nuwara Eliya were abandant with natural enemies of aphids. Alyokhin et al. (2011) and Mohd Rasdi et al. (2012) have found out that aphid and whitefly population reach low due to their natural enemies without chemical control interventions.

Table 1. Potato tuber yield of insecticide treated and untreated plots during Maha 2016/17, Yala 2016, Maha 2017/18 and Yala 2018

Treatments Yield (t/ha)Maha

2016/17 Yala 2017

Maha 2017/18

Yala 2018

Weekly interval insecticides application 33.7 37.1 27.1 40.2 Bi-weekly interval insecticides application 33.1 34.2 25.7 39.0 Untreated control 32.5 33.7 25.1 37.8 CV % 9.09 5.44 8.54 14.6NS-not significant

100 Hettiarachchi et al.

Figure 1. Aphids and whitefly population in insecticide treated and untreated plots during Maha 2016/17, Yala 2017, Maha 2017/18 and Yala 2018 (N=8 and 4 replicates)

Figure 2. Average temperature, rainfall (A) and Relative humidity (B) in Maha 2016/17, Yala 2017, Maha 2017/18 and Yala 2018

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Tuber yieldThere was no significant difference observed between insecticide treated and

untreated plots during the four seasons (Table 1). This is mainly due to the low pest population development and the absence of viral disease infestations during four seasons. Evans et al. (2000), Machangi et al. (2003) and Nasruddin and Mound (2016) have pointed out that potato tuber yield reduction is caused by heavy infestation of aphid, whitefly and viruses.

ConclusionThis study revealed no significant yield reduction in the plots treated for aphids

and whiteflies weekly and bi-weekly compared to that of untreated under up country wet zone condition in Sri Lanka. Therefore, routine application of insecticides on potato for the control of the above pests is economically unproductive and insecticide application on aphids and whiteflies could be avoided.

ReferencesAlyokhin, A., F. A. Drummond, G. Sewell and R. H. Storch. 2011. Differential effects of weather

and natural enemies on coexisting aphid populations. Environ. Entomology 40: 570-580.

Evans A. 2000. Aphids and aphids borne virus diseases in potatoes. Technical note. The Scottish Agriculture College, Edinburgh.

Jha S. K. and M. Kumar. 2018. Fluctuation in whitefly Bemisia tabaci population in relation to environmental factors. Journal of Entomology and Zoology Studies 6: 3011-3014.

Kelm M., I. Fostiak and W. Kadlubiec. 2009. Factors determine the number of aphids/Hemiptera, Aphidoidea/ in conventional and organic potato crops, Aphids and other Hemipterous Insects 15: 85-105.

Machangi, J.M., F.M. Olubayo, J.H. Nderitu, R.W. Njeru, R. El-bedewy1 and E.O. Obudho. 2003. Effect of aphids and virus diseases on yield of seed potatoes in Kenya. African Crop Science Conference Proceedings 6: 220-223.

Mohd Rasdi, Z., M.R.C. Salman, A.A. Hassan, D. Hamady, A. Hamaseh and F. Ismail. 2012. Field Evaluation of Some Insecticides on Whitefly (Trialeurodes vaporariorum) and Predator (Macrolophus caliginosus) on Brinjal and Tomato Plants. Asian Journal of Agriculture and Rural Development. 2: 302-311.

Nasruddin, A. and L.A. Mound. 2016. First record of Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae) severely damaging field grown potato crops in South Sulawesi, Indonesia. Journal of plant protection research 56: 199-202.

Seasonal Report. Maha 2006/2007, Yala 2017. 2017. Agriculture Research Station, Sita Eliya, Department of Agriculture, Sri Lanka.

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Performance and comparative advantage of pineapple export from Sri Lanka

P.S.R. Premarathna

Socio Economics and Planning Center, Department of Agriculture, Peradeniya, Sri Lanka

IntroductionPineapple plays an important role in fruit sector, which is being one of the leading

commercial fruit crops in Sri Lanka. The present extent grown recorded as 4,783 ha and production reached about 52,786 mt (Dept. of Census, 2017). Sri Lanka has been exporting pineapple in both fresh and dried form. Pineapple has earned USD 5,027,595 of foreign earning by exporting 1,206 mt in year 2017 (ITC, 2017). However, there are continued variations that could be observed in pineapple exports. As a commercial venture, it is important to examine performance and the comparative advantage of pineapple exports from Sri Lanka to determine the strategies for improving the sector.

Materials and methodsThe export values and quantities of Sri Lanka and World wereextracted from

International Trade Center (ITC)and the data has been spanned from 2001 to 2017. Performance of pineapple exports were worked out on triennium basis. Analysis of export performance done through the method of Export Performance Ratio (EPR), which is also called as Revealed Comparative Advantage (RCA) suggested by Balassa (1965) as follows:

RCA = (Xijt÷Xit)/ (Xiwt÷ Xiw)…………………(1) Where;

Xijt = Value of Sri Lanka’s export of Pineapple (fresh and dried) at time “t”

Xit= Value of Sri Lanka’s export edible fruit and nuts at time “t”

Xiwt= Value of World total export of pineapple (fresh and dried) at time “t”

Xwt= Value of World total export of edible fruit and nuts at time “t”

As once RCA ratio is greater than unity it says that country has comparative advantage in export of the commodity. However, RCA possesses the issue of asymmetry, as the index indicates the value from zero to infinity and not comparable on both side of unity. This index has been transformed to, Revealed Symmetric Comparative



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Advantage (RSCA) and expressed mathematically as; RSCA = (RCA—1)/ (RCA +1). Then the index ranges between -1 to +1 and a commodity exhibits comparative advantage if RSCA value is positive.

Results and discussionStatus of Sri Lanka’s pineapple exports

The exports of pineapple have been presented in quantitative and value terms in Table 1 and data presented in triennium ending (TE) basis. The study concerned on pineapple category listed under the HS 080430, which denoted the fresh and dried form of pineapple exports. Table 1. Export of pineapple from Sri Lanka, average for triennium ending (2002-2017)

Year Quantity (mt) Value USD '000 Unit value (USD/mt)TE 2002 2423.67 1628.67 671.98TE 2005 2946.00 2157.00 732.18TE 2008 1852.67 2993.33 1615.69TE 2011 1013.33 1790.00 1766.45TE 2014 2732.33 3129.33 1145.30TE 2017 1459.67 4683.33 3208.50

Note: Computation made by author on the basis of international trade statistics in ITC and FAOSTAT

The data reflects that pineapple export has increased from 2423.67 mt in TE 2002 to 2946.00 mt at the TE 2005. In value terms, it has been increased from USD 1628.23 thousand to USD 2157 thousand. At next triennium ending (TE 2008) the export quantity has declined up to 1852.67 tons whereas export earning has increased up to US$ 2993.33 thousand. This has been proved by the increase in unit value of pineapple from 732.18 USD/mt at TE 2005 to 1615.69 USD/mt at TE 2008. Though, the unit value of pineapple exports has been maintained at higher level at TE 2011, it dropped to USD 1145.30 per 1 mt at TE 2014. However, the unit value of pineapple export has been increased up to USD 3208.50 per 1 mt at the triennium ending in 2017. Therefore, the study being evidenced the fluctuation of export prices of pineapple in Sri Lanka during the period.

104 Premarathna et al.

Table 2. Destinations for pineapple export from Sri Lanka (Triennium Ending 2017)Country Value

USD'000 TE 2017

Value Percentage (% ) to total

Quantity mt TE 2017

Quantity Percentage (% ) to total

Avg. unit value USD/mt TE 2017

Germany 1236.67 26.42 159.67 10.94 7745.30USA 1199.33 25.62 158.33 10.84 7574.74UAE 558.67 11.93 627.00 42.95 891.02France 390.67 8.34 114.00 7.81 3426.90Austria 336.33 7.18 27.67 1.89 12156.63Maldives 282.33 6.03 177.33 12.15 1592.11Netherlands 133.67 2.86 16.67 1.14 8020.00Canada 111.33 2.38 17.33 1.19 6423.08UK 104.67 2.24 34.67 2.37 3019.23Switzerland 76.67 1.64 6.33 0.43 12105.26Other countries 251.33 5.37 121.00 8.29 2077.13Total 4681.67 100.00 1460.00 100.00 3208.50

TE = Triennium Ending Avg. = averageNote: Computation made by author on the basis of international trade statistics in ITC

Countries’ share of pineapple import from Sri Lanka has been presented for the triennium ending at 2017 in Table 2. In quantity base, the largest share of pineapple has been exported to United Arab Emirates (UAE) which was almost 43% of total volume whereas the share of total earning was 11.93%. The 2nd largest quantity was exported to Maldives (12.15% of total quantity). In contrast, the quantity base export share of Germany and USA was showing similar shares of 11% and recorded the highest export share on value basis. In terms of value realization of pineapple export, European countries and USA has given higher unit price compared to UAE and Maldives. Austria and Switzerland have depicted the highest unit value yet their export volume is comparatively low.

Comparative advantage of Sri Lanka’s pineapple export In a liberalized world trade system, prevalence of consistent comparative

advantage is one of the important factors that assure the commodity trading. The comparative advantage of pineapple export from Sri Lanka has been depicted through revealed comparative advantage (RCA) and revealed symmetric comparative advantage (RSCA). The estimated RCA and RSCA values are presented in Table 3.

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Table 3. Revealed comparative advantage (RCA) and revealed symmetric comparative (RSCA) advantage of pineapple export form Sri Lanka (2001-2017)

Year RCA RSCA2001 2.52 0.432005 1.72 0.262009 1.08 0.042013 1.46 0.192017 1.55 0.22

Note: Computation done by author on the basis of international trade statistics in ITC and FAOSTAT

Pineapple export of Sri Lanka has comparative advantage, though RCA and RSCA have revealed unstable behavior during the study period (2001-2017). It is notable that the comparative advantage of pineapple exports has been reduced significantly during 2001-2009. Regardless of descending behavior of pineapple export, it has shown increasing movement from 2013 to 2017.

ConclusionThe study being evidenced the fluctuation of export prices of pineapple in Sri

Lanka during the period of 2001-2017. In terms of value realization of pineapple export, European countries and USA have given considerably higher unit price compared to other large importers i.e. UAE and Maldives. The comparative advantage indexes (RCA and RSCA) have depicted unpredictable pattern of pineapple export. Therefore, it is vital to address the confines which are impeding the pineapple exports from Sri Lanka while identifying the other potential destinations.

AcknowledgementAuthor wish to thank the Directors of SEPC at Peradeniya and FRDI, Horana, Sri Lanka for

their encouragement and providing facilities to carry out this study.

ReferencesBalassa, B. 1965. Trade liberalization and revealed comparative advantage, Manchester School

of Economics and Social Studies. 33 (2): 99-124

Department of Census and Statistics. 2017. Agricultural and Environmental Statistics Division, 2017.

International Trade Center (ITC). 2017. - International trade statistics 2001-2019 . [online]. http://www.intracen.org/itc/market-info-tools/trade-statistics (Accessed on 05.06.2018)

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Usage of potato micro tubers in slow growth conservation

E.S.C. Edirisinghe, K.M.G. Kulathunga and C.H. Denagamage

Plant Genetic Resource Center, Gannoruwa, Peradeniya, Sri Lanka

IntroductionPotato is a tetraploid, highly heterozygous plant and segregates on sexual

reproduction. Therefore, genetic integrity of the crop is maintained via vegetative propagation. Micro tubers, which originate from in-vitro plants and more tolerant to light and temperature variations than in-vitro microplants. They do not have the requirement of frequent sub-culturing instead of maintaining microplants. Micro tubers are convenient for handling, storage and exchange of germplasm than microplants (Tovar et al., 1985). However, their use in germplasm conservation is not common (Gopal et al., 1998). Micro tubers can be stored for a long period of time without losing their viability. Therefore, it represents a better alternative to microplants as a means of conservation and crop improvements (Ashmore, 1997). Potato germplasm has been conserved in the form of in-vitro cultures as a mandatory duty and national responsibility of the Plant Genetic Resources Centre (PGRC) of the Department of Agriculture as a national responsibility (PGRC manual, 1985). But in-vitro microplants have short subculture period of 4-6 months, resulting frequent transferring, which is cumbersome and costly. Therefore, the current research was conducted as an initial step to understand the use of micro tubers for slow growth conservation with long term goal of applying for other accessions as well.

Materials and methodologyIn-vitro grown shoots of three potato accessions, Bio Technology Potato

(BTP) 16 (CIP 800959), BTP 02 (CIP 390478.9), BTP 07 (CIP 397012.22) were used. Cultures were multiplied in 40 ml of potato multiplication medium (PMM), Murashige and Skoog (1962) medium (MS) supplemented with 0.1 mg/l NAA, 0.5 mg/l BAP, 0.1 mg/l Gibberelic Acid (GA3), 30 g/l sucrose and 8 g/l agar. Cultures were incubated at 24 oC temperature, 60 to 65% relative humidity under 16 /8 hour light/ dark photoperiod and 42-46 µmolm-2S-1 (Philips 36W/54) light intensity. The cultures were further multiplied in the same medium in liquid form under same condition. Each treatment consisted of ten replicates and each replicate consisted of ten microplants. 3 months incubation period was given for culture multiplication. Then the cultures



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were transferred into 40 ml of tuberization medium, MS with 5 mg/l of BAP and 80 g/l sucrose (in-vitro conversation labora-tory, PGRC). The cultures were incubated at 15 oC temperature under continuous dark for 90 days. After three months, tuberized cultures were hardened at room temperature for 10 days. Tubers were harvested under the laminar flow cabinet and tubers per bottle were counted and tuber diameter was recorded. Harvested tubers were dried for ten days and tubers were sorted under four different categories, < 0.3 cm, 0.3-0.5 cm, 0.5-1.0 cm, 1.0 cm according to diameters. Then, five tubers each was placed in sterilized 5ml test tubes and kept under three different temperatures, 1 °C, 4 °C and 24 °C. Each treatment combination was consisted of five replicates. Tuber regeneration was tested in three months after conservation. In-vitro tuberization trial was laid out as Completely Randomized Design and ANOVA performed to analyze data. Effects of accessions on tuber sizes were analyzed using categorical data analysis. Treatment means were compared using Duncan’s Multiple Range Tests (DMRT) and analysis performed with SAS potable 9.

Results and discussionIn in-vitro tuberization, analysis of variance showed that the micro tuber

production was significantly different among selected three accessions at probability level p=0.05. BTP 16 (CIP 800959) showed the highest and mean number of tuber production as 2.47 (tubers/micro plant) while the lowest resulted in accession BTP 07 (CIP 397012), it was 1.32. 1.56 mean number of tubers per microplant accession BTP 02 (CIP 390478.9) was produced. Gopal et al. (2004), highlighted that the genotypic differences were positively correlated with micro tuber production in potato. Islam (1995) reported that micro tuber initiation time varied with genotype. Tuber sizes were significantly different among accessions. The biggest micro tuber size 04, (>1.0 cm) was produced by accession BTP 07 (CIP 397012.22) followed by accession BTP 02 (CIP 390478.9). However, BTP 16 did not produce tubers >1 cm. BTP 16 produced the highest number of tubers in the tuber diameter categories of 0.3-0.5 cm and 0.5-1.0 cm. BTP 02 also produced more tubers in the same categories as well. Similar mean number of tubers was resulted in < 0.3 cm category from BTP 02 and BTP 16. BTP 07 produce the lowest tuber numbers in 0.5-0.1 cm range while its highest tuber numbers were resulted under >1 cm category (Figure 1). Nasiruddin and Rafiul (2018) were reported that tuber size depends on culture media and its genotype.

108 Edirisinghe et al.

Figure 1. Accessions response for different sized micro tuber formation in MS + with 5 mg/l of BAP and 80 g/l sucrose medium.

There is a need for developing genotype specific protocol for efficient microtube-rization and it is important in planting material production system (Gopal et al., 2004). However, it may be difficult to develop genotype specific protocols for germplasm conservation. Hence, optimized cost effective techniques such as in-vitro induced reproductive organs can be applied (Nasiruddin and Rafiul, 2018). After 90 days, it was observed that all the treatment levels conserved under 4 °C and 24 °C showed 100% auto germination but micro tubers conserved at 1 °C could not show auto germination. The observation was common for all tested accessions. Gopal et al. (2002), reported that fresh micro tubers could be conserved satisfactorily in 6±1 °C for 15 months. However, micro tubers stored under 1 °C showed 100% tuber germination ability in PMM by producing shoots representing all the tuber categories of all accessions.

ConclusionPotato accession (BTP) 16 (CIP 800959) produced the highest total number

of micro tubers than tested other two accessions, BTP 02 (CIP 390478.9) and BTP 07 (CIP 397012.22). Micro tuber sizes are accessesion dependent and the highest micro tubers resulted in 0.5 - 0.1 cm diameter categories. Selected accessions cannot be conserved neither at 4 °C nor 24 °C temperatures at least for 3 months. All the tuber categories of three accessions can be conserved at 1 °C temperature for three months with 100% survival. Effective conservation period for micro tuber conservation at 1 °C temperature is to be identified by testing of germination percentage in regular time intervals.

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AcknowledgementAuthors wish to acknowledge Dr W.L.G. Samarasinghe, Additional Director/

PGRC for the provision of research facilities for this research. Our sincere thanks also go to Dr S.K. Wasala, Additional Director/ HORDI for her support given to statistical analysis. The staff of in-vitro conservation laboratory is highly appreciated for their continuous support given to make this research a success.

ReferencesAshmore, S.E. 1997. Status report on the development and application of in-vitro techniques for

the conservation and use of plant genetic resources. International Plant Genetic Resources Institute, Rome. 67.

Gopal J, A. Chamail and D. Sarkar. 2004. In-vitro production of micro tubers for conservation of potato germplasm: effect of genotype, abscisic acid, and sucrose. In-vitro Cell. Dev. Biol.—Plant 40:485–490.

Gopal, J., J.L. Minocha and H.S. Dhaliwal. 1998. Microtuberization in potato (Solanum tuberosum L.). Plant Cell Reports 17:794–798.

Gopal, J., C. Anjali and S. Debabrata. 2002. Slow-growth in-vitro conservation of potato germplasm at normal propagation temperature. Potato Research. 45(2-4): 203–213

Islam, M.S. 1995. Indigenous potato varieties of Bangladesh: Characterization by RAPD markers and production of virus free stock. Ph. D. Dissertation. Dept. of Horticulture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706. Bangladesh

Murashige T. and F. Skoog. 1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15:473–497.

Nasiruddin, M. and A.K.M.I. Rafiul. 2018. In-vitro slow-growth conservation for two genotypes of solanum tuberosum l. Bangladesh J. Bot. 47(3): 369-380.

Plant Genetic Resource Centre (PGRC).1985. PGRC Manual.

Tovar P., R. Estrada, L. Schilde-Rentschler and J.H. Dodds. 1985. Induction and Use of In- vitro Potato Tubers. CIP Circular 13. CIP, Lima, Peru. 1-5.

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Response of rice to site specific application of fertilizer

W.M.U.K. Rathnayake1, M.G.N. Rupasinghe2, D.N. Sirisena, W.M.N. Wanninayake1, K. Karunarathne1 and H.A.D.I. Maduroshika2

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka

2Regional Rice Research and Development Center, Bombuwala, Sri Lanka

IntroductionApplication of low rate of fertilizer diminishes the crop yield while high rates

of fertilizer enhances the accumulation of nutrients in the soil. This accumulation reduces the long term productivity in paddy fields and it may become a threat to long-term sustainability of paddy cultivation in Sri Lanka (Sirisena et al., 2016). To cope up with nutrient accumulations and to obtain a higher production per unit fertilizer, a soil test based fertilizer recommendation (STB) was introduced by the Department of Agriculture (DOA) in 1993. Because of the practical difficulties faced in getting soil samples analyzed at DOA soil testing laboratories at the time they needed, only a few farmers tested their soils before application of fertilizer. The policy of giving fertilizer at subsidized rates has worsened the situation. To encourage farmers to test their soils before application of fertilizer, DOA has decided to study the feasibility of introducing soil test kits to analyse soils at the time they need. As the first step of formulating soil test kit based fertilizer application, it is necessary to find out the most suitable soil test values beyond which fertilizer addition is not necessary. On the other hand, it is necessary to find out the fertilizer levels, need to be applied at different levels of nutrient in the soil. Therefore, experiments were conducted to find out the most suitable soil nutrient values beyond which fertilizer addition is not necessary and to find out fertilizer levels need to be applied at different levels of soil nutrients.

Materials and methodsSuitability of soil nutrient values introduced in 2013 to obtain optimum crop

production was evaluated for rice crop in Maha 2017/2018 in 26 farmer fields in Polonnaruwa, Kalutara and Kurunegala, districts covering Dry, Wet and Intermediate zones of Sri Lanka. Experiments were set up 11 locations in Kurunegala district, 6 locations in Polonnaruwa district and nine locations in Kalutara district. One replicate experiment was set up in each location. Irrespective of the location, there were five treatments in the experiments. They were, 1). Zero N, 2). Zero P, 3). Zero K, 4). Soil Test



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Based PK (STB) and 5) application of recommended level of N, P and K as in the DOA recommendation (DOA). Fertilizer levels for treatment number 4 was selected based on the soil nutrient values of the location. Soil test based fertilizer recommendations introduced by the Rice Research and Development Institute in 2013 (RRDI, 2013) was used to select fertilizer levels based on level of soil nutrients (Table 1).

Table 1. Soil Test based fertilizer recommendation for irrigated PaddyAvailable P

values (mg/kg)(Olsans’P)

Exchangeable K ppm

Recommend TSP fertilizer levels (kg/ha)

Recommended MOP levels (kg/ha)

4 WAE 6 WAE< 5 < 40 55 25 35

5 – 10 40 – 80 30 20 25>10 80 – 160 Nil 10 10

>160 Nil Nil

Soil sample collected from each location before land preparation were analyzed for pH, electrical conductivity (EC), available P (Olsen’s method), exchangeable K and organic matter contents. Estimated TSP levels according to soil P levels of paddy fields are shown in the Table 1. Paddy soils in the Kurunegala district had high level of soil P and K as such out of 11 locations only one location received full dose of TSP fertilizer. Accordingly, out of 11 locations; 4 locations received full dose of MOP fertilizer while 6 locations received 2/3 of the recommended MOP level and two locations received 1/3 of the recommended MOP level. None of the locations were suitable to grow rice without application of K fertilizer. In Polonnaruwa district out of 6 locations; four locations received no P fertilizer while two locations received half of the recommended TSP level. None of the locations were suitable to grow rice without K fertilizer. However three locations received 2/3 of the recommended, one location received 1/3 of the recommended and two locations received full dose of MOP fertilizer. In the Kalutara district, there were nine locations. Out of the nine, only one location received P fertilizer and others received no P fertilizer. Soil K levels were higher in Kalutara district than Kurunegala and Polonnaruwa districts and as such two locations in the Kalutara district received no K fertilizer. Five locations received 2/3 of the recommendation while one location received 1/3 of the recommended level. Crops were established and managed as recommended by the Department of Agriculture. Experimental plots were harvested at maturity, yield data were collected and statistically analyzed using SAS 9.1 statistical package. Single replicate experimental analysis method developed by Abeysiriwardena et al. (1991) was used to analysis yield data.

112 Rathnayake et al.

Results and discussionSoil test results were summarized for each district and average, maximum and

minimum values are given in the Table 2.

Table 2. Some soil fertility characters of the experimental sites. Area Level of

parameterspH (1: 2.5

soil: water)EC (dS/m) (1:5 soil :

water)

P mg/kg K mg/kg OM%

Kurunegala Average 7.2 0.05 15.7 61.6 1.6Maximum 7.9 0.07 41.8 114.0 2.7Minimum 6.5 0.03 4.2 28.0 0.8

Polonnaruwa Average 7.4 0.07 12.5 58.3 1.5Maximum 7.9 0.10 18.4 102.0 2.7Minimum 7.1 0.04 6.4 31.6 0.4

Kalutara Average 4.9 0.08 18.6 99.4 8.8Maximum 5.3 0.20 34.9 184.8 16.0Minimum 4.6 0.02 5.5 53.1 2.4

By looking at these results it can be assumed that soil pH and EC in all the experimental sites were at the suitable level for growing rice (Bandara, 2006). Since organic matter content is below the critical level (3%), application of organic manure is necessary to paddy soils in the Kurunagala and Polonnaruwa districts to obtain maximum paddy yields (Bandara, 2006). Results of all three districts have clearly shown that application of N fertilizer is necessary to obtain a better yield of rice (Table 3). Maximum available soil P of the rice growing soils in Kurunegla, Polonnaruwa and Kalutara were 41.8, 18.4 and 34.9 mg/kg, respectively. Therefore, application of P fertilizer is not necessary to obtain a better rice crop from these sites. On the other hand, minimum available soil P of the rice growing soils in Kurunegla, Polonnaruwa and Kalutara were 4.2, 6.4 and 5.5 mg/kg, respectively. So that application of full dose of P fertilizer is necessary for these sites to obtain a better rice crop. Omission of phosphorous from the recommendation has not shown any yield reduction in Kurunegala district (Table 3) while significant reduction in yield due to omission of P was observed in Polonnaruwa and Kalutara districts (Table 3). Therefore, level of soil P in the soil test based P application can be practiced for all three districts. Maximum exchangeable K levels in Kurunegala and Polonnaruwa were 114.0, 102 mg/kg respectively (Table 2). Accordingly, even at the maximum soil K levels, it is not possible to grow rice without application of some amount of K fertilizer in Polonnaruwa and Kurunegala paddy soils. In comparison to Kurunegala and Kalutara districts soil P and K levels were low in the

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Polonnaruwa district. This may be a reason for lower paddy yields obtained when P and K was omitted from fertilizer application in Polonnaruwa district. It is known that, in the Wet zone areas iron toxicity problem prevailed in many paddy fields (Bandara and Gunathilake, 1994) and as such omission of either P or K without considering the other did not give good results. As a result even with high level of available P and exchangeable K in the initial soil, omission of P and K gave a significantly lower yield in the Kalutara distrcit. Since there was no significant difference in yield and no significant deviation from maximum response between STB and DOA recommendation, application of fertilizer saves fertilizer and enhances the productivity of rice per unit fertilizer. Table 3. Mean yield of rice to different levels of fertilizer from 11 locations in the Kurunegala district and mean and variance of the deviation from maximum response in each location Treatment Kurunegla Polonnaruwa Kalutara

Mean yield (t/ha)

Deviation from maximum response

Mean yield (t/ha)


Mean yield (t/ha)


Mean Variance Mean Variance Mean VarianceN0 4.7 B 2.6 A 4.53 2.8 C 2.3 A 0.65 3.9 B 0.7 A 3.51P0 6.9 A 0.5 BC 3.41 4.5 B 0.6 B 1.05 3.7 B 1.1 A 3.62K0 7.0 A 0.4 BC 3.48 4.6 B 0.5 B 1.52 4.1 B 0.7 A 4.82STB 6.9 A 0.7 B 4.53 4.7AB 0.4BC 1.80 4.7 A 0.1 B 5.34DOA 7.3 A 0.2 C 3.63 5.1 A 0.02 C 1.28 4.6 A 0.2 B 4.42

Same letters appeared in each column are not significantly different at p= 0.05STB- Soil Test Based fertilizer applicationDOA- Department of Agriculture recommended fertilizer application

ConclusionStudy concludes that application of N fertilizer is necessary to obtain a better

yield of rice. Available P values above 10 mg/kg and exchangeable K values above 160 mg/kg are the most suitable soil test values beyond which P and K fertilizer addition is not necessary. On the other hand, available P values and exchangeable K values recommended to decide the fertilizer P and K requirement for rice under the soil test based fertilizer recommendation for rice can still be used. It is further concluded that omission of either P or K alone should not be practiced even with high level of P and K in the Kalutara district.

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AcknowledgementAuthors wish to acknowledge the financial support given by FAO to conduct

these experiments under FAO TCP project, (TCP/SRL/3606). They also wish to acknowledge the technical support given by Dr. P. Weerasinghe, National Project Coordinator of the FAO TCP project, (TCP/SRL/3606) and the Director HORDI.

ReferencesAbeysiriwardena D., S. de Z, G.R. Buss and P.P. Reese JR. 1991. Analysis of multi-environmental

yield trials for testing adaptability of crop genotypes. Tropical Agriculturist. 147: 85 – 96.

Bandara, W.M.J. 2006. A Site–specific fertilizer recommendation for rice (Oryza sative L.) using a systemic approach to soil fertility evaluation. Thesis submitted in partial fulfillment of the requirement of the degree of Doctor of Philosophy in Agriculture. University of Peradeniya, Sri Lanka.

Bandara W.M.J., G.A. Gunathilake. 1994. Effect of applied K and P on bronzing in rice grown in iron toxic soils. J. Nat. Sci. Coun. Sri Lanka. 22 (3): 219 – 230.

DOA. 1993. Soil – Test Based Fertilizer Recommendations. A Technical Working Document for Soil Scientists of the Department of Agriculture, Peradeniya, Sri Lanka. 30.

RRDI. 2013. Soil Test Based Fertilizer Recommendations. A Technical Working Document. 30.

Sirisena D.N., W.M.N. Wanninayake and A.G.S.D. Silva. 2016. Long term application of organic manure and chemical fertilizers on rice productivity and fertility in paddy growing soils in Kurunegala district. Annals of Sri Lanka Department of Agriculture 2016. 18: 124-132

Rathnayake et al.

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Growth and yield performance of different planting materials of potato variety granola in hydroponic and aeroponic systems

H.A.S.N. Hettiarachchi, A.M.N. Amarasingha, A.G.C. Babu, K. Dayani, A.P. Rathnakumara and M. Premalatha

Agriculture Research Station, Sita Eliya, Nuwara Eliya, Sri Lanka

IntroductionHydroponic and aeroponic are newly introduced technologies aimed to increase

the quantity and quality of seed potato production as a solution for less availability of high quality seed potato in Sri Lanka. Seedlings obtained from the seeds harvested from Rooted Stem Cuttings (RSC) are used to produce pre-basic seeds in aeroponics or hydroponics conventionally. Direct planting of potato in-vitro plantlets is considered to be the most efficient way to produce pre-basic seed potato to minimize the accumulation of diseases in the process of seed production. Micro tubers also considered as high quality planting material for pre-basic seed production. Hence, it is imperative to study the performance of different planting materials in hydroponic and areroponic systems to obtain high yield under local conditions. Therefore this research was conducted to identify the most appropriate planting materials under aeroponic and hydroponic systems.

Materials and methodsThe experiment was carried out during year 2017 as two experiments (trial 1

and 11) in Hydroponic and Aeroponic polytunnels at the Agriculture Research Station, SitaEliya. There were four treatments; T1- in-vitro plantlets, T2-Seedlings obtained from mini-tubers, T3- Seedlings obtained from micro tubers and T4-Seedlings obtained from RSC seeds arranged in a Complete Randomized Design (CRD) with ten replicates and 100 plants per treatment.

All four types of seedlings were established in hydroponic and aeroponic systems at 15 cm x 15 cm spacing. Albert’s mixture is dissolved in water as nutrient and EC was maintained at 1200 µs during the first two weeks and thereafter at 1500 µs till maturity. This solution is used to provide nutrients in both systems. In aeroponic system Albert’s solution was sprayed for 5 seconds at 20 minutes interval. In hydroponic system nutrient solution was circulated at 60 minutes interval. 10-20 mm mini-tubers were harvested starting from one month after planting and continued at 3-4 days interval for 3 1/2 months.



116 Hettiarachchi et al.

Plant height and stolen length at 4 weeks after transplanting and number of mini-tubers per plant at each harvest were recorded. Data were analyzed using ANOVA with SAS statistical package version 9.1. Means were compared using the Least significant difference test at p<0.05.

Results and discussionPlant height and stolen length

Plant height and stolen length of seedlings obtained from RSC seeds were significantly higher than that of any other planting material tested in hydroponic system (Table 1). However in-vitro plantlets recorded the lowest growth. The higher rate of growth recorded in seedling derived from RSC seeds could be attributed to higher amount of food reserves already available for their growth compared to in-vitro plantlets. This result was in agreement with Perira et al. (2009). Chang et al. (2012) reported that poor performance of in-vitro plantlets could be due to limitations in adequate aeration of root amongst other factors. In-vitro plantlets, although, acclimatized in polytunnel for two weeks, may have needed more time to recover from change of environmental conditions. Sharma and Pandey (2013) pointed out that pretreatment of the in-vitro plantlets before transplanting and subsequent crop husbandry management techniques are two crucial aspects for concern.

On the other hand, in-vitro plantlets recorded higher plant height and stolen length than that of seedlings obtained from different type of seed tubers in aeroponics (Table 2). This faster growth of in-vitro plantlets in aeroponics could be due to better root growth environment available. In aeroponic system, roots are hanged in an air chamber where roots are exposed to sufficient aeration to absorb more oxygen. Also, frequent refreshed supply of nutrients facilitated efficient absorption of nutrients. This would have triggered off the faster development of in-vitro plantlets in aeroponic system. Ritter et al. (2001) also observed faster growth of in-vitro plantlets in aeroponics due to higher absorption of nutrients than in regular hydroponics.

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Table 1. Plant height, stolen length at 4 weeks after transplanting and average number of mini-tubers per plant in hydroponic system during 2017 at ARS, SitaEliya

Treatments Plant Height at 4 weeks after

transplanting (cm)

Length of stolen at 4 weeks after

transplanting (cm)

Average no of mini-tubers/

PlantTrail 1 Trail 11 Trail 1 Trail 11 Trail 1 Trail 11

In-vitro plantlets 13.7c 11.5b 25.6b 23.0c 62.3ab 35.5c Seedlings from mini-tubers 31.9b 23.7a 44.0a 39.0b 55.5b 49.3b Seedlings from micro tubers 11.5c 15.1b 12.7c 37.1b 23.0c 33.0c Seedlings from RSC seeds 46.6a 25.0 a 48.8a 52.7a 72.6a 61.5a CV% 14.2 25.3 23.6 32.9 28.7 26.7

*Mean values with same letter were not significantly different at 5% level of probability

Table 2. Plant height, stolen length at 4 weeks after transplanting and average number of mini-tubers per plant in aeroponic system during 2017 at ARS, SitaEliya

Treatments Plant height at 4 weeks after transplanting

(cm)

Stolen length at 4 weeks after transplanting

(cm)

Average no of mini-tubers/Plant

Trial 1 Trial 11 Trial 1 Trial 11 Trial 1 Trial 11In-vitro plantlets 35.2a 50.3a 55.85a 99.45a 54.7a 66.2a

Seedlings from mini-tubers 32.8b 57.85a 60.3a 93.25ab 49.5ab 36.4b

Seedlings from micro tubers 32.05b 29.0b 57.2a 77.1b 45.8b 38.3b

Seedlings from RSC seeds 32.55b 31.3b 49.2b 81.1b 44.10b 34.1b

CV% 6.67 34.67 9.69 22.51 17.45 68.05*Mean values with same letter were not significantly different at 5% level of probability

Tuber YieldThe tuber yield per plant of the seedlings from RSC seeds was significantly

higher under hydroponic system in trial 1 and 2. While the seedlings obtained from micro tuber gave the lowest yield in hydroponic system (Table 1). According to the result of experiment conducted by Pereira et al. (2009), mini-tubers were more productive than in-vitro plantlets under hydroponic system. This could be due to more influence of food reserves in seeds which influence the initial development of plants. In-vitro plantlets gave a significantly higher yield under aeroponic system in both experiments (Table 2). According to the Brocic et al. (2018), in-vitro plantlets in aeroponic system influenced significantly on the production of number and total yield of potato mini-tuber. He also found out that certain varieties can perform better under aeroponics. In the present study performance of variety granola is very good in term of tuber yield. Otazu (2007) also showed that in-vitro plantlets yield more tubers than other conventional materials when produced under aeroponics and hydroponic systems.

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ConclusionIn-vitro plantlets are the most appropriate planting materials of potato variety

Granola for efficient pre basic seed potato production in aeroponic system. The seedlings obtained from the rooted stem cuttings found to be the most suitable planting material under hydroponic system.

ReferencesBrocic O., M. Milinkovic, I. Momcilovic, D. Postic, J. Oljaca, B. Veljkovic and D. Milosevic.

2018. Production of potato mini-tubers in the aeroponic growing system, Journal on Processing and Energy in Agriculture. 22: 49-52.

Chang, D.C., C.S. Park, S.Y. Kim and Y.B. Lee. 2012. Growth and tuberization of hydroponically grown potatoes. Potato Research 55: 69-81.

Otazu, V. 2007. Quality seed potato production using aeroponics, A potato production manual. Lima Peru.

Pereira J.E.S., C.A.B. Medeiros, G.R.D.L Fortes and A.D.S Pereira. 2009. Production of pre-basic potato seed by polyvinyl chloride PVC- articulate gutters hydroponic system, Brazilian Archives of biology and Technology. 52

Sharma, K.A. and K.K. Pandey. 2013. Potato mini-tuber production through direct transplanting of in-vitro plantlets in green or screen houses-A review. Potato Journal 40:95-103.

Ritter, E., B. Angulo, P. Riga, C. Herran, J. Relloso and M. Sanjose. 2001. Comparison of hydroponic and aeroponic cultivation systems for the production of potato mini-tubers. Potato Research 44:127-135.

Hettiarachchi et al.

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Assesment of native Trichoderma species against Rigidoporus and Fusarium isolates pathogenic to jak trees

M. Kuruppu, N.S. Jayawardhana and R.K. Nilmini

Fruit Research and Development Institute, Kananwila, Horana, Sri Lanka

IntroductionThe soil is a reservoir of inocula of soil borne plant pathogens and they cause

a wide array of soil borne diseases in a range of economically important crops, while silently hidden in the rhizosphere. Majority of soil-borne plant pathogens are widely distributed in agricultural soils. The fungal pathogens responsible for root rot and collar rot of jak were revealed as Rigidoporus microporus, Fusarium oxysporum and Fusarium solani in a previous study. R. microporus is the causal agent of white root disease which is a serious disease in rubber plantations in Sri Lanka (Jayasuriya and Wettasinghe, 2004). F. solani and F. oxysporum have been confirmed to pathogenicity of several other perennial trees suffering from root and stem rots (Javid et al., 2005).

Biological control through rhizosphere inhabiting microorganisms has been reported as a promising component in integrated management of root diseases of perennial trees. Among a wide range of potential bio-control agents of soil borne pathogens, Trichoderma spp. are in the forefront. Wider availability in many root ecosystems, free-living nature and ability to control pathogenic microbes through a wide range of modes of antagonism are favorable attributes that Trichoderma spp. possess, as biological control agents. They are considered as promising biological control agents against numerous phytopathogenic fungi since they are capable of inhibiting phytopathogenic fungi either by including resistance and plant defense reaction or by direct antagonism through mycoparasitism and competition or by producing antibiotics. Considering the multi-functional antagonistic ability of Trichoderma spp., the isolated species were tested in the present study to determine their efficiency in controlling R.microporus, F.oxysporum and F. solani the root rot/collar rot causing pathogens of jak tree. Through this in-vitro assay, it was intended to observe the mode of antagonism, especially focusing on competition, antibiosis and mycoparasitism.



120 Kuruppu et al.

Materials and methodologySix isolates of Trichoderma (T. hamatum, T. harzianum, T. viride, T. koningiopsis,

T. gamsii and T. erinaceum) were tested against R. microporus (R. microporus SEG and R. Microporus PM52) and Fusarium isolates (oxysporum and solani) which were isolated and molecularly confirmed in a previous study as the root rot and collar rot causal agents of jak. It was done by dual culture plate technique using PDA as the culture medium. PDA was used as the culture medium based on the results of the previous experiments on colony growth of fungal isolates on different culture media. Dual culture plate technique as described by Jayasuriya and Thennakoon (2007) was followed to check the antagonism of different Trichoderma isolates against the fungal pathogens, in-vitro. Briefly, an isolate of the fungal pathogens was inoculated on to PDA plate and three days later, an isolate of Trichoderma was inoculated to same plate with a distance of 3.5 cm. For six Trichoderma isolates, six separate experiments were carried out according to a complete randomized design with 10 replicates. The dual culture plates were incubated at room temperature under natural light conditions and pH of the medium was adjusted 5.5 which favors the growth of both organisms. For each experiment, controls were maintained by culturing the fungal isolate without the influence of Trichoderma isolate. Radius of the colony growth under the influence of Trichoderma and without the influence of Trichoderma was measured for each fungal isolate. Percentage colony growth inhibition of a given fungal pathogen was calculated using the following equation. Data was analyzed using SAS statistical software version 9.1 and significance of the effect of each Trichoderma isolate on colony growth inhibition was determined by ANOVA and mean separation was done by Duncan’s Multiple Range Test.

R1 – radius of the pathogen away from the antagonist (Trichoderma spp.) (cm)

R2 – Radius of the pathogen towards to the antagonist (Trichoderma spp.) (cm)

Percentage colony growth inhibition of the pathogen =R1- R2 x 100% R1

Results and discussionPercentage colony growth inhibition of the fungal pathogens by the six

Trichoderma spp. is summarized and depicted by Table 1.

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Table 1. Percentage colony growth inhibition of R. Microporus and Fusarium isolates by Trichoderma species in dual cultures

Trichoderma spp.

% of growth inhibition of root and collar rot pathogensRmj1 Rmj8 Fo Fs

T. hamatum 81a 24a 45ba 28cb

T. viride 42b 34a 70a 51ba

T. koningiopsis 26b 20a 50ba 50abc

T. gamsii 30b 21a 25b 25c

T. harzianum 25b 33a 67a 67a

T. erinaceum 24b 20a 53a 48abc

CV% 2.44 2.44 2.44 2.44Means with the same letter along given a column are not significantly different at P = 0.05

Rmj1 and Rmj8 were denoted as microporus two isolates which were molecularly equal to microporus SEG and R. microporus PM52 respectively. Fo and Fs were denoted as F. oxysporum and F. solani respectively.

Except for Rmj8 isolate, percentage colony growth inhibition of other fungal pathogens varied significantly under the influence of a given Trichoderma speices used for antagonistic assay (Table 1). For example, Rmj1isolate had the higher colony growth inhibition by T. hamatum. The rest of the five Trichoderma speices showed a significantly lower colony growth inhibition of Rmj1 than that by T. hamatum, and there were no significant differences of the inhibition ability among those five species (Table 1). With reference to F. oxysporum, the higher percentage colony growth inhibition was shown by T. viride and the lowest was shown by T. gamsii, T. harzianum and T. gamsii gave the highest and lowest colony growth inhibition of F. solani respectively.

It was observed that some of the Trichoderma species, namely T. hamatum, T. harzianum and T. erinaceum developed inhibition zones against Rmj1 and Rmj8 isolates and the colony growth of the two pathogens was inhibited (Table 2). No such inhibition zones were observed with the other Trichoderma species with the four fungal pathogens or the three Trichoderma species given in Table 2 with Fusarium isolates.

Table 2. Inhibition zones developed by Trichoderma species with R. Microporus isolates Trichoderma species Radius of the inhibition

zone (cm) with Rmj1Radius of the inhibition

zone (cm) with Rmj8T. hamatum 0.5 0.7T. harzianum 0.9 1.2T. erinaceum 0.9 1

Therefore, based on the observations of Table 1 and 2 the mode of antagonism of the six Trichoderma species used, can be summarized as follows (Table 3).

122 Kuruppu et al.

Table 3. Different modes of action of Trichoderma spp. Against fungal pathogens Trichoderma

speciesRmj1 Rmj8 Fo Fs

T. hamatum Competition and antibiosis

Competition and antibiosis

Competition Competition

T. harzianum Competition and antibiosis



T. erinaceum Competition and antibiosis



T. viride Competition Competition Competition CompetitionT. koningiopsis Competition Competition Competition CompetitionT. gamsii Competition Competition Competition Competition

Jayasuriya and Tennakoon (2007) have explained the possibility of introducing biological control agents, particularly Trichoderma spp. to management of white root rot pathogen of rubber. Isolation of T. harzianum from rubber growing soils in Sri Lanka and its high efficiency in controlling R. microporus has been reported by Jayasuriya and Tennakoon (2007). The results showed the availability of a wide range of Trichoderma spp. in the rhizosphere of homegardens and hence potential of using them for the biological control of root and collar rot diseases of jak. In-vitro efficiency of the six Trichoderma spp. used in this study to control the four fungal isolates, it was also observed the mode of antagonism exhibited by the Trichoderma spp. Findings of the peresent study revealed the ability of some Trichoderma spp. (i.e. T. viride, T. harzianum, T. gamsii, T. hamatum) to exhibit competiton and the ability of some Trichoderma spp. (i.e. T. erenacium, T. harzianum) to show antibiosis against the four fungal isolates. Our observations are in par with Kaewchai and Soytong (2010), who have reported similar observations. According to Kaewchai and Soytong (2010), T. hamatum STN07 and T. harzianum STN07 have shown more than 50% colony growth inhibition of R. microsporus through competition by rapidly growing over the colony of the pathogen. Bastakoti et al. (2017), have reported the bio-control ability of Trichoderma isolate TS215 against Fusarium solani has shown inhibition of the fungal pathogen (F. solani), and it has been suggested the antagonistic ability of the Trichoderma could be due to release of antibiotic or antibiotic-like substances. However, our findings revealed that a given isolate of a pathogen species show variation in colony growth inhibition by different Trichoderma spp. Moreover, different isolates of a given pathogen species showed variation in colony growth inhibition when subjected to the control by the six Trichoderma spp. Such biological variations are possible when biological control

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is practiced. Therefore, use of all potential Trichoderma spp. identified in the present study, as a mixture would be a more effective, as we have to target on several root rot and collar rot pathogens.

ConclusionAll six Trichoderma spp. were capable of inhibiting colony growth of the four

fungal pathogens under in-vitro conditions at varying degrees. Except for R. microporus (Rmj8) isolate, percentage colony growth inhibition of other fungal pathogens varied significantly under the influence of a given Trichoderma speices used for antagonistic assay. Competition and antibiosis were identified as the modes of antagonism of the Trichoderma spp. used for the study.

ReferencesBaskoti S, S. Belbase, S. Manandhar and C. Ariyal. 2017. Trichoderma species as biocontrol

agents against soil borne fungal pathogens.

Javid A., R. Bajwa and A. Shoaib. 2005. Fusarium root and stem rot of Erythrina suberosa Roxb. In Pakistan.

Jayasuriya K.E and B.I. Thennakoon. 2007. Biological control of Rigidoporus microporus, the cause of white root disease in rubber.

Jayasuriya K.E and D.S. Wettasinghe. 2004. The control of white root disease in Sri Lanka

Kaewchai S. and K. Soytong. 2010. Application of bio-fungiide against Rigidoporus microporus causing white root disease of rubber trees, Journal of Agricultural Technology. 6(2): 349-363.

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Weed seed entry to Sri Lanka with imported vegetable seed

Y.M.H. Liyanage1, S.M.A.R. Abekoon2, P.K.K.Wijayanthi1, K.M.P.D. Karunarathne2, H.M.J.C.K. Herath1 and K.L.M.I. Kondasinghe1

1Central Seed Testing Laboratory, Gannoruwa, Peradeniya, Sri Lanka2Seed Certification Service, Gannoruwa, Sri Lanka

Introduction Seed is considered as a major input in agricultural production. However, it is

effective carrier of invasive species across international borders. Sri Lanka imports about 1500 mt of vegetables and other field crop seeds annually (Personal communication). The National Plant Quarantine Service (NPQS) has taken several measures to minimize pest introductions including a mandatory import permit requirement under the provisions of the Plant Protection Act (PPA) for seed and planting material importation.

As an import permit condition, seed consignments entering Sri Lanka need to be accompanied either with an Orange International Seed Lot Certificate of ISTA (International Seed Testing Association) or government seed analysis report of the exporting country, if no ISTA-accredited laboratories are available.

Veronica arvensis (Cramer, 1981) and Parthenium hysterophorus (Marambe, 2012) were introduced weeds to Sri Lanka through imported seeds. Similar cases of many invasive plant introductions through global commerce have been recorded (Mack et al., 2000; Shimono and Konura, 2008). More recently, noxious weed species were detected in some of the seed lots by NPQS of Sri Lanka (Warshamana et al., 2012: Nimanthika, 2014). Several seed consignments of radish, knolkhol and carrot have been rejected when those were sampled and tested by the Seed Certification Service. Therefore, the objective of this paper was to compare information given in seed lot certificates with the local testing results and identify any lapses in the seed import permits which could lead the entry of weeds in to Sri Lanka.

Materials and methodsSeed quality data of 427 imported bulk vegetable seed samples tested during

2013 to 2018 in the Central Seed Testing Laboratory, Gannoruwa were taken for this study. Data on crop, family, country of origin and the seed quality, seed purity and number and names of weed species found were taken from seed testing database.



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Seed analysis reports which came along with the imported consignments from importing country were obtained from Seed Certification Service Head Quarters, Gannoruwa. Following data were collected by checking each and every analysis reports. The type of the analysis report/type of the laboratory: ISTA or non ISTA and Other Seed Determination (OSD) was done or not done (this was done by checking a statement under other determinations) were recorded by reading each analysis report. The data was analyzed using MINITAB statistical software.

Results and discussionAccording to local testing results, several regulated weed species were detected

in radish, carrot, knol kohl and leeks seed consignments. Fallopia convolvulus L., Rumex crispus L., Galium aperine L. and Chenopodium album L. were detected in different vegetable seed lots imported from Vietnam. According to crop protection compendium (www.cabi.org/CPC), Fallopia convovulus L. is widely distributed in Europe, Japan and India. A possibility of a strong establishment of Fallopia convovulus in Sri Lanka was confirmed by a Pest Risk Analysis (PRA) (Nimanthika, 2014).

Table 1. Regulated weed species found in one kilogram of each consignment of imported vegetable seed consignments during 2013-2018

Year Crop Country Lot number

Family of the other seed

Regulated species No. of seeds/ kg of sample

2013 Radish Thailand 130626 Rubiaceae Galium aparine L. 302014 Radish Thailand 140205 Rubiaceae Galium aparine L 552016 Carrot Vietnam 150915 Amaranthaceae Chenopodium album L. 69

Radish Vietnam R03 Polygonaceae Fallopia convolvulus L. 17Rubiaceae Galium aparine L. 17

Radish Vietnam R03r Rubiaceae Galium aparine L. 6Knol khol India 6386 Rubiaceae Galium aparine L. 69

2017 Leeks Vietnam L08 Polygonaceae Fallopia convolvulus L. 43Carrot South

AfricaZAO6318 Asteraceae Centaurea sp. 18

Knol khol Vietnam K06 Polygonaceae Rumex crispus L. 34Radish Thailand 161209 Rubiaceae Galium aparine L. 144

2018 Radish Italy 116/448 Rubiaceae Galium aparine L. 13

Determination of other seed by ISTA and Non ISTA Laboratories are given in Table 2. Other Seed Determination is more frequently (17% of the total submitted samples) done by ISTA laboratories than non ISTA laboratories. Irrespective of the type of laboratory only 8% of seed consignments had reports on determination of other

126 Liyanage et al.

seeds while 92% of consignments were accompanied reports with no information on the same. Further, most of those reports and our local test reports indicated 0.0 or Trace for other seed (%) in the physical purity test. It is because purity test result report to nearest 0.1%. Trace is indicated if the proportion is less than 0.05% (ISTA rules, 2013). Weight may not be indicated because of the very light weight of the weed seed composite. Table 2. Relationship between conducting other seed determination test and the laboratory type

Laboratory type Number of reports with other seed determinations (indicating OSD test)

Conducted Not conducted ISTA 35 (17%) 172 (83%)Non ISTA 1(0.5%) 219 (99.5%)Total 36 (8%) 391(92%)

(Percentages are given in the parenthesis)

All the testing reports of Vietnam and Thailand were issued by government laboratories. However, without information given on other species mixed in those seed lots. Further, three ISTA accredited laboratories in Italy, South Africa and India have not indicated the presence of regulated weeds seed species in their ISTA reports although they were detected during local testing. It is therefore, advisable to revise the permit condition that the seed testing laboratory in the exporting country must indicate the names and the numbers of other seed found in all seed consignments, especially of carrot, knol kohl and radish seeds destined for Sri Lanka.

ConclusionRegulated weed seeds are observed in bulk imports of radish, carrot and knol-

khol seeds. Verification of foreign seed analysis reports on surface value alone cannot be considered as a fool-proof quarantine measure to prevent entry of regulated weeds to Sri Lanka. The existing loop hole in the import permit condition should be rectified to insist that above vegetable crop seed consignments destined for Sri Lanka must be tested by ISTA and non-ISTA laboratories to indicate names of other species and their seed count in test reports.

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ReferencesCramer, L.H. 1981. Scrophulariaceae. In A Revised Handbook to the Flora of Ceylon. Eds.

M.D. Dassanayake and F.R. Fosberg. Amerind Publishing Co., New Delhi. 1: 386 – 449.

ISTA. 2013. International Rules for Seed testing.2013.pp.1-14 International Seed Testing Association, Bassersdorf, Switzerland. ISBN-13 978-3-906549-72-9

Marambe, B. 2012 Alien invasive plants threatening the Agro-Ecosystems of Sri Lanka Assessment and management of alien species that threaten ecosystems, habitats and species. CBD technical series. ISBN: 92-807-2007. 96 – 98.

Mack, R.N.D., W.M. Struberloff, H. Evans, M. Clout and F.A. Bazzaz. 2000. Biotic invasions: causes, epidemiology, global consequences, and control. Ecol. Appl. 10: 689-710.

Nimanthika, W.J. 2014. Fallopia convolvulus (L) (Poligonaceae): Predicting potential environmental and economic impact to Sri Lanka. Annals Sri Lanka Department of Agriculture.16: 247-262.

Shimono, Y. and A. Konura. 2008. Effects of human- mediated processes on weed species composition in internationally traded grain commodities Weed Research 48(1):10 – 18.

Warshamana I.K., R.W.P.M. Rajapakshe and S.C. Wanigasooriya. 2012. The potential for introducing pests through imported consignment of agricultural commodities. Annals of the Sri Lanka Department of Agriculture 14:173-185.

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In-vitro multiplication of gac fruit (Momordica cochinchinensis Lour. Spreng.)

D.A. Shirani1, S.H.C.K. Dharmarathna2, A.W. Gaminie1 and D.A.B.N. Amarasekara2

1Grain Legume and Oil crops Research and Development Centre, Angunakolapelessa, Sri Lanka

2Faculty of Agriculture, University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka

IntroductionMomordica cochinchinensis Lour. Spreng. commonly known as gac fruit belongs

to family cucurbitaceae. High market demand exists for the processed products of the M. cochinchinensis aril because of its high phyto-nutrient content. The red aril of a ripe fruit contains very high amounts of lycopene (3.728 mg/g) and β carotene (0.379 mg/g) (Nhung et al., 2010). These amounts are at least 5 times higher lycopene than in tomato (Lenucci et al., 2009) and 8 times higher carotenoids (β carotene) content reported than in carrot (Cephola et al., 2012). Gac fruit is mainly propagated through conventional methods like seed propagation, rooted cuttings, swollen root tubers and grafting. Seed propagation has several constrains due to its dioecious nature. Rooted vine cuttings and grafting are effective in vegetative propagation. Commercial cultivation of Gac fruit is mainly threatened by virus diseases and vegetative propagation increases the risk of spreading such diseases. So, there must be a propagation method to multiply virus free planting materials. Micro-propagation techniques are very much useful for popularizing the cultivation of this important crop in the country to provide clean planting materials. Therefore, the present experiment was undertaken to micro-propagate the Gac fruit with specific objectives to optimize the surface sterilization method and to identify suitable growing and shoot elongation for in-vitro multiplication.

Materials and methodsHealthy immature shoots were collected from a well-maintained female M.

cochinchinensis mother plant grown in the research field of Grain Legume and Oil crops Research and Development Centre, Angunakolapelessa. Explants were washed under running tap water for 15-20 minutes and cut in to manageable pieces and those cuttings were thoroughly washed with a liquid detergent (5% teepol) for 10 minutes. For further sterilization shoot cuttings were dipped in 70% ethyl alcohol for 30 seconds followed by HgCl2 in 3 different concentrations (0.1, 0.3 and 0.5%) for 5 and 10



129

minutes. Then the shoot cuttings were rinsed 3 times with sterilized distilled water. 1cm long nodal segments were cultured in solid MS medium (Murashiga and Skoog, 1962) and the experiment was laid in CRD with 20 replicates. Non contamination percentage and the survival percentage were calculated 2 weeks after culturing. In the second experiment, surface sterilized two types of explants (shoot tip (ST) and nodal cuttings (NC)) were cultured in 4 different media combinations (M1:MS+2 mg/l BAP+0.1 mg/l IAA, M2: MS+1 mg/l BAP+0.1 mg/l IAA, M3: 2 mg/l BAP+0.1 mg/l IAA+0.2 mg/l GA3 and M4: MS+1 mg/l BAP+0.1 mg/l IAA+0.2 mg/l GA3). Experiment was setup as 2 factor factorial in CRD with 20 replicates. All the cultures were incubated in the culture room at 26±1 oC temperature, under 2000-3000 lux light intensity, providing 16/8 D/N photoperiod. Data on number of non-contaminated explants, number of survived explants, number of shoots per explant and length of the shoots were collected and transformed where appropriate before analyzing. Data were analyzed using SAS portable version 9.1.3 following ANOVA and mean separation.

Results and discussionSurface sterilization of explants

The statistical analysis revealed that there exist significant differences among treatments with reference to the non-contamination and survival percentages of explants at p = 0.0001 (Table 1) .

Table 1. Non contamination and survival percentages of explants 2 weeks after culture initiation in different treatment combinationsTreatment

% of HgCl2 (w/v) Time duration (min)

Mean percentageNon contamination Survival

T1 0.1 5 14e 100e

T2 0.1 10 24d 100e

T3 0.3 5 74c 94d

T4 0.3 10 88b 90c

T5 0.5 5 90b 60b

T6 0.5 10 98a 46a

CV% 12.6 8.41Means with different letter along the column are significantly different at p=0.05

Due to the perennial nature of the crop and exposure to the high temperature conditions in the field, elimination of microorganisms was quite difficult. Therefore, strong sterilants were required. Mercuric chloride is highly toxic. Therefore, the concentration and the time duration of the treatment must be optimized to minimize tissue mortality of the explants caused by over sterilization. According to the results

130 Shirani et al.

0.3% HgCl2, for 10 minutes (T4) could be chosen as the most efficient concentration for surface sterilization of shoot cuttings. Due to high non contamination percentage (88%) and survival percentage (90%) of that treatment was higher than other five treatments (Table 1).

Selection of suitable growing medium for shoot induction of M. cochinchinensisIn this experiment four combinations of media were tested with two types of

explants. As shoot proliferation is promoted by BAP in the presence of IAA, constant level of IAA was added to all media with different levels of BAP and GA3. Then the number of shoots per explant was counted 6 weeks after culture initiation. Formation of callus at the base of the explants was observed in majority of the cultures and it may be due to the addition of auxin; IAA. In spine gourd micro-propagation, callusing and adventitious shoot productions have been reported in media containing BA and NAA (Nabi et al., 2002). Shekwhat et al. (2011) also observed callus formation at the cut end of nodal segments of spine gourd when IAA present (>1 mg/l) along with BAP in the medium.

Statistical analysis of data showed the interaction effect of medium and explants was highly significant on mean number of shoots per explant (at p=0.0001). According to Figure 1, the maximum number of shoots (5.6) per explant was obtained from the nodal segments cultured on MS medium supplemented with 2 mgl-1 BAP +0.1 mg/l IAA+ 0.2 mgl-1 GA3.

NC: nodal cuttings, ST: shoot tips, M1- M4: MediaCV% = 7.2

Figure 1. Effect of different treatment combinations on number of shoots per explant of Momordica cochinchinensis

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The highest multiplication rate was also observed (25.8/vessel) with nodal cuttings cultured in medium containing 2 mg/l BAP+0.1 mg/l IAA+0.2 mg/l GA3 (Table

2).Table 2. Effect of different treatment combinations on the rate of multiplication

Treatment combination No. of explants/subcultureNCM1 14.6c

STM1 13.88c

NCM2 10.4e

STM2 11.8d

NCM3 25.8a

STM3 16b

NCM4 14.5c

STM4 10.6e

CV% = 6.2Means with the different letter are significantly different at p=0.05

The findings of the present study were in agreement with results reported by Shekhawat et al. (2011). They found MS medium containing 2 mgl-1 BAP + 0.1 mgl-1 IAA as the most suitable medium for bud breaking of M. dioica and 4-6 shoots were regenerated per explant.

Length of in-vitro shootsSignificant differences in shoot lengths were observed among the treatment

combinations at p=0.0001. Out of all the treatments the nodal segments showed the maximum shoot length (5.3 cm) in media containing 2 mg/l BAP + 0.1 mg/l IAA+0.2 mg/l GA3 and 1 mg/l BAP + 0.1 mg/l IAA+0.2 mg/l GA3 (Figure 2).

NC: nodal cuttings, ST: shoot tips, M1-M4: MediaCV% = 7.9Figure 2. Effect of different treatment combinations on mean length of shoots

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In-vitro rootingThe shoots were transferred to MS medium supplemented with 1 mg/l IAA for

rooting. However, very poor rooting was observed and it may be due to the perennial nature of the species (data are not shown). Rooting studies need to be undertaken to develop a protocol for planting material production.

ConclusionShoot cuttings of Gac fruit collected from filed grown mature wines could

be surface sterilized using 0.3% HgCl2 for 10 minutes after treating them with 70% ethyl alcohol for 30 seconds. Nodal explants cultured in the medium containing 2 mg/l BAP + 0.2 mg/l GA3 + 0.1 mg/l IAA performed better than the shoot tips in in-vitro multiplication.

ReferencesCephola, M., B. Pace, M. Renna, P. Santhamaria, A. Signore and F. Serio. 2012. Compositional

analysis and antioxidant profile of yellow, orange and purple polignanao carrots. Italian Journal of Food Science. 24: 284-291.

Lenucci, M.S., A. Caccioppola, M. Durante, L. Serone, M.D. Caroli, G. Piro. 2009. Carotinoid content during tomato (Solanum lycopersicum L.) fruit ripening in traditional and high-pigment cultivars. Italian Journal of Food Science. 21:461-472.

Murashige, T. and Skoog, F. 1962. A revised medium for rapid growth and bio assays with tobacco tissue cultures. Physiologiaplantarum, 15(3): 473-497.

Nabi, S.A., M.M. Rashid, M. Al-Amin and M.G. Rasul. 2002. Organogenesis in teasel gourd (Momordica dioica Roxb.). Plant Tissue Culture, 12(2):173–180.

Nhung, D.T.T., P.N. Bung, N.T. Ha and T.K. Phong. 2010. Changes in lycopene and beta carotene contents in aril and oil of gac fruit during storage. Food chemistry. 121:326-331.

Shekhawat, M.S., N.S. Shekhawat, K. Ram, M. Phulwaria and A.K. Gupta. 2011. High frequency plantlet regeneration from nodal segment culture of female Momordica dioica (Roxb.). Journal of Crop Science and Biotechnology. 14(2):133-137.

Shirani et al.

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Factors affecting the satisfaction of agricultural products suppliers at Hadabima authority

M.G.W.S. Kariyawasam and A.S. Rathnayake

Seed and Planting Material Development Centre, Peradeniya. Sri Lanka

IntroductionSri Lankan business pattern is more concerned about customers and very little

about the suppliers. But, exploring the factors that contribute to supplier satisfaction can be linked to enhance supply chain effectiveness, customer satisfaction, buyer supplier relationship and more over a management tool for strategic positioning of the supply chain.

Purpose of this study is to investigate the supplier satisfaction by exploring the factors that contribute to supplier satisfaction. These research findings can provide practical contributions that are beneficial to agribusiness managers where they can enhance their competitiveness in the industry through the development of sustainable buyer-supplier relationships.

Agribusiness has traditionally been a challenging and competitive industry. Recent natural disasters (e.g. droughts, flooding) and economic instability have led to significant changes in the market conditions across the industry and cost pressures are building up on agribusinesses. While the current situation may not be favorable to many agribusinesses, they need to remain competitive. Hence, many agribusinesses rely on fewer but more efficient and reliable business partners those are willing to establish long-term sustainable relationships, in which they can seek complementary resources, create synergy and add value to their respective business.

While business-to-business (B2B) relationships have been investigated extensively in the last decade (Ng, 2010; Andersen and Kumar, 2006; Rauyruen and Miller, 2007; Caceres and Paparoidamis, 2007), there is only a limited number of researches on the effects of these changes in agribusiness. Limited studies (Wilson, 1995; Bagdoniene and Zilione, 2009; Eid et al., 2002) have evaluated the success factors for developing B2B relationships, particularly from a dyadic perspective between supplier and buyer within the agribusiness industry. Therefore, the purpose of this study is to investigate the supplier satisfaction by exploring the factors that contribute to supplier satisfaction.



134 Kariyawasam et al.

Satisfaction defined as “a positive affective state resulting from the appraisal of all aspects of a firm’s working relationship with another company” in business relationship (Anderson and Narus, 1984). Satisfaction evolves as a consequence of one party's experience with the other's ability to fulfill norms and expectations (Biong, 1993).

Managing supplier satisfaction levels is thus essential to the future success of an organization, which implies that supplier perceptions regarding organizational image, relationship building and processes are understood. Through the use of supplier opinion surveys, various levels of supplier satisfaction are evaluated. These include: overall satisfaction over a period of time, key drivers of satisfaction including pricing, relationship management, ordering, receiving and payment and operational activities in relation to each satisfaction driver.

A supplier opinion survey is a management tool used to improve and further develop internal and external processes with suppliers and partners in the supply chain network. Survey results are inputs to the organization’s strategic planning as well as its every day operations and behavior. It is important for an organization to measure those activities in which it has recently invested, or areas in which performance is poor.

General objectives of this study is to find out the types and amounts of fruits, vegetables and value added products supplied to the sales outlet of Hadabima by both beneficiaries and non-beneficiaries and specific objective is to find out the level of satisfaction of suppliers at Hadabima Authority.

Conceptual Framework

Hadabima Involvement • Quality Control • Order Management • Pricing and Payments

Supplier Characteristics • Attitude • Relationship • Age • Experience

Supplier Satisfaction

Situational Factors • Land extent • Type of products • Distance to the Hadabima Other Factors

• Environment • Political • Economical • Social • Technological

Market Behavior • Price fluctuation • Demand • Competition

135

Materials and methods Study was conducted at the Sales outlet of Hadabima Authority, Gannoruwa.

Population of the study was suppliers who are the beneficiaries of development projects undergone by Hadabima Authority as well as registered non beneficiaries of Hadabima Authority. Total of 35 suppliers from the above population were randomly selected as the sample, using field sampling method. Data collection was done by using, questionnaire survey, key informant discussions with marketing staff, face to face interviews with suppliers and observations also done at Hadabima supply channel. For data analysis, descriptive statistics was used along with bar charts and pie charts. Further analysis was done by correlation.

Results and discussionAccording to gender, supplier involvement is much higher in males (63%) than

female’s respondent. The age range of suppliers varied from 25 to 64 years. The highest percentage (48.9%) of suppliers was in the age range of 45-54 years category. The distribution shows that the youngest age range of suppliers was 25-34 years.

With respect to supplying experience around 23% of the population has more than 3 years of supplying experience, while 40% of the population has 2-3 years of supplying experience.

Figure 1. Supplying experience of respondent

With respect to supplier categories, non-beneficiaries play a major role (60%), while beneficiaries consist of 40% in supplier channel.

According to item of supplies it was found that the highest percentage of respondents (66.77%) supplied vegetable and the next highest preference was fruits (30.05%).

136 Kariyawasam et al.

Figure 2. Distribution of supply items Most of the categories of suppliers were slightly satisfied on given price by

the Hadabima Authority. There were few categories of suppliers not satisfied and as well as fully satisfied on given price. With respect to overall satisfaction among supply categories, there were no dissatisfied supplier categories. Majority were slightly satisfied or satisfied on overall satisfaction.

According to Correlation Matrix for selected variables related to overall satisfaction, there is a positive relationship among quality maintained and price satisfaction, higher the quality received higher price, Lower the quality ends up with lower price. There is a significant negative relationship between qualities maintain and price amends. Whenever market price goes down Hadabima immediately revise the price. But, whenever market price goes up no immediate action for price revision. Therefore, then lower quality maintained. There is a significant positive relationship between price satisfaction and overall satisfaction which is a general truth. There is a negative relationship between price amendments and overall satisfaction.

ConclusionThe first objective of the study was to find out the types and amounts of

fruits, vegetables and value added products supplied by both beneficiaries and non-beneficiaries. It was found that, vegetables and fruits are the major products supplied by both beneficiaries and non-beneficiaries.

The specific objective of the study was to find out the level of satisfaction of supplier. It was found that there were no dissatisfied suppliers. Majority were slightly satisfied or satisfied on overall satisfaction. Satisfaction varies with price amendments, purchase price, payments, category of supply etc.

Non-beneficiaries play a major role in supplier channel at Hadabima Authority while beneficiaries underutilized the market facilitation. The focus areas of the survey results can be used as inputs for strategic planning and as actions in day to

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day management decision making at Hadabima Authority. Awareness is required to influence beneficiaries to utilize the marketing opportunities.

AcknowledgementThe authors are grateful to all the staff members of the Hadabima Authority,

Gannoruwa and Seed and Planting Material Development Cenrtre, Peradeniya for their support in conducting this study.

ReferencesAnderson, J.C and J.A. Narus. 1984. A model of the distributor’s perpective of distributor

manufacturer working partnerships. J Mark 1984(48): 62–74.

Andersen, P. H. and R. Kumar. 2006. Emotions, trust and relationship development in business relationships: A conceptual model for buyer-seller dyads. Industrial Marketing Management. 35(4):522-535.

Biong, H. 1993 Satisfaction and loyalty to suppliers within the grocery trade. European journal of marketing. 27(7): 21–38.

Caceres, R. C. and N.G. Paparoidamis. 2007. Service quality, relationship satisfaction, trust, commitment and business-to-business loyalty. European Journal of Marketing. 41(7): 836-867.

Rauyruen, P. and K.E. Miller. 2007. Relationship quality as a predictor of B2B customer loyalty. Journal of Business Research. 60(1): 21-31.

Ng, E. 2010. Understanding B2B supplier selection relationships: the case of Taiwan agribusinesses. Journal of Business-to-Business Marketing, 17(2):149-172.

Wilson, D. T. 1995. An integrated model of buyer-seller relationships. Journal of the Academy of Marketing Science. 23(4): 335-345

Bagdoniene, L. and R. Zilione. 2009. Business to Business Relationships: The Variables in the Context of Success. Social Sciences. 4(66): 16-25.

Eid, R., M. Trueman and A.M. Ahmed. 2002. A cross-industry review of B2B critical success factors. Internet Research. 12(2): 110-123.

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Use of gliricidia (Gliricidia sepium) leaves as a source for organic nutrient management of watermelon (Citrullus lanatus)

K.A. Renuka, P.G.R.K. Wickramasekara, H.L.G.R. Hewawasam, R.D.M. Ranaweera and K.R.S. Chamarika

Fruit Research and Development Institute, Horana, Sri Lanka

IntroductionWatermelon (Citrullus lanatus) of cucurbitaceae family originated from West

Africa subsequentlyspread to tropical and subtropical regions (Jarret et al., 1996). Watermelons are predominantly grown in Dry and Intermediate zones of Sri Lanka. However, well drained soils in wet zone are also suitable for watermelon cultivation. Sri Lankan farmers mainly rely on chemical fertilizer for watermelon cultivation. Therefore, some local consumers and exporters request organically grown watermelon. There is no systematic nutrient management protocol exists for organic watermelon production in Sri Lanka. Green manure has been considered as an ideal source for sustaining soil fertility in organic farming (Fageria, 2007; Joergensen, 2002, Palm et al., 2001). Leaves of Gliricidia (Gliricidia sepium) are used as a green manure (Wiersum and Nitis, 2016). Gliricidia leaves decompose rapidly and provide nutrients to the soil (Lehmann, 1995). Hence, this study was aimed to evaluate the potential of gliricidia leaves as a source of organic manure for organic nutrient management of watermelon.

Materials and methodsAn experiment was conducted in 2017 and 2018 at the Fruit Research and

Development Institute, Horana. Research field is located in Low Country Wet zone (WL1b) agro ecological region and the great soil group is Red yellow Podzolic soil, Hapludults (Panabokke, 1996). Two different locations of the research field were selected for two years. In 2017 and 2018, soil properties of the experiment site were pH 5.5, 5.6 (1:2.5), exchangeable potassium 77, 174 mg/kg, available phosphorus 38, 25 mg/kg, organic matter 2.2% 1.7% respectively. Efficacy of three different levels of gliricidia leaves as a manure were compared with Department of Agriculture (DOA) recommended fertilizer mixture and zero fertilizer application. Treatments were: 1. No fertilizer 2.105 kg N/ha, 90kg P2O5/ha, 105 kg K2O/ha and 10 t/ha compost (DOA recommendation) 3. Gliricidia leaves 7.5 t/ha 4. Gliricidia leaves 15 t/ha 5. Gliricidia leaves 30 mt/ha. Gliricidia leave were incorporated in to soil in three equal splits at 2 week before planting, 2 weeks after planting (WAP) and 4 weeks after planting. Fresh



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leaves were left on the soil for 2-3 days prior to incorporation. Seeds of variety Rocky were planted in 4 m x 5 m sized plots with 1m x1m spacing and two seedlings were maintained at one place. Treatments were arranged in Randomized Complete Block Design with four replicates. Nitrogen, P2O5 and K2O were applied as Urea Triple Super Phosphate and Muriate of potash respectively. Total amount of nitrogen and K2O was applied as three equal split at 2-3 days before planting 2 weeks after planting and five weeks after planting. Total amount of phosphorus was applied as basal. Compost was applied one week before planting. Pest management and irrigation were done according to DOA recommendations. Fresh fruit yield, total soluble solid of fruit, leaf nutrient (N, P and K) level at first flowering stage were measured. Most recent fully developed leaves were taken at flowering stage for leaf analysis. Soil and plant samples were analyzed using standard methods. Statistical analysis was performed using the SAS statistical package version 9.1.

Results and discussionResult revealed that fresh fruit yield increased with increasing levels of

gliricidia. Fruit yield of DOA recommended fertilizer applied treatment and that of the gliricidia leaves at the rate of 15 mt/ha were not significantly different. Furthermore no significant yield difference was observed in application of gliricidia leaves at the rate of 15 mt/ha and 30 mt/ha (Table 1). Gliricidia application did not show a significant effect on total soluble solids content of fruits in comparison with chemical fertilizer application (Table 1).

Table 1. Fresh fruit yield and total soluble solid of different treatments in 2017 and 2018Treatments Fresh fruit yield (t/ha) Total soluble solid (%)

2017 2018 2017 2018No fertilizer 19.23c 9.6c 8.2a 8.2a

105 kgN/ha,90 kgP2O5/ha, 105 kg K2O/ha, 10 mt compost /ha

29.3a 20.2a 9.1a 9.0a

Gliricidiarate - 7.5 mt/ha 25.2b 11.8bc 8.5a 8.1a

Gliricidiarate - 15 mt/ha 30a 17.4ab 8.9a 8.4a

Gliricidiarate - 30 mt/ha 33.9a 21.1a 9.0a 8.9a

CV% 13 28 6 8Note: In each column, means followed by the same letters are not significantly different at 5% probability level

Leaf nitrogen and potassium levels were increased with increasing levels of gliricidia (Table 2). Compared the gliricidia application rate of 15 mt/ha and DOA recommended fertilizer application, leaf nitrogen levels were not significantly different

140 Renuka et al.

(Table 2). Significant difference was not observed in leaf potassium level at gliricidia application rate of 15 mt/ha, 30 mt/ha and DOA recommendation. No significant differences were observed for leaf phosphorus level of gliricidia application rates, DOA recommendation and zero fertilizer application. Hence, phosphorus requirement of the plant might be fulfilled by soil available phosphorus level.

Table 2. Nitrogen potassium and phosphorus % (dry weight basis) in most recently matured whole leaf with petiole sampled at first flowerin different treatments in 2018

Treatment N (%) K (%) P (%)No fertilizer 0.59d 2.60d 0.14a

105 kg N/ha, 90 kg P2O5/ha, 105 kg K2O/ha, 10 mt/ha compost

1.31b 4.73a 0.17a

Gliricidia rate - 7.5 mt/ha 0.95c 2.98dc 0.16a

Gliricidia rate - 15 mt/ha 1.30b 3.96 ab 0.17a

Gliricidia rate - 30 mt/ha 2.46a 4.63a 0.17a

CV% 27 14 20

Note: In each column, means followed by the same letters are not significantly different at 5% probability level

ConclusionSoil incorporation of gliricidia leaves increased yield of watermelon and yield

increments were depend on the application rate of gliricidia leaves. Application of gliricldia leaves increased leaf nitrogen and potassium level. Fresh fruit yield of DOA recommended fertilizer application was comparable to Gliricidia leaves application rate of 15 mt/ha. Hence, gliricidia leaves could be used to organic nutrient management of watermelon and application of gliricidia leaves at the rate of 15 mt/ha fulfilled the nutrient requirement of watermelon.

ReferencesFageria, N.K. 2007.Green manuring in crop production, Journal of plant nutrition. 30: 691-719.

Jarret, B. R. Bill, W. Tom and A. Garry. 1996. Cucumber germplasm report, Watermelon National Germplasm System. Agricultural service, USDA. pp.29-66.

Joergrnsen, R.G. 2002. Challenges to organic farming and sustainable land use in the tropic and sub tropic, Journal Agri Tropic and Sub tropic. 103: 105-106.

Lehmann, J., G. Schrothand W. Zech. 1995. Decomposition and nutrient release from leaves, twigs and roots of three ally crop tree legumes in Central Togo Agroforestry System. 29: 21-36.

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Palm, C.A., C.N. Gachengo, R.J. Delve, G. Cadishand K. E. Greller. 2001. Organic input for soil fertility management in tropical agroecosystems: application of an organic resource base. Agriculture Ecosystem Environment. 83: 27-42.

Panabokke, C.R. 1996. Soil and agro ecological environment of Sri Lanka. Natural resources, Energy and Science Authority of Sri Lanka.

Wiersum, K. F. and I.M. Nitis. 2016. Gliricidiasepium. https//uses.plantnet-project.org/ Gliricidia Sepium

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Species diversity and dominance in Kandyan homegardens

A.G. Chandrapala, K.M.A. Kendaragama, I.C. Gunasekara and S.K. Wettasinghe

Natural Resources Management Center, Department of Agriculture, Peradeniya, Sri Lanka

IntroductionThe tropical homegardens are indicative of complex, multi-layer structure of

the natural forest with a rich plant diversity (Kumar et al., 2004) and are shaped by deliberate planting or retention, and assisted regeneration of useful woody species (Nair, 1993). This traditional agro-forestry system represent a valuable source of genetic resources, in addition to the natural and planted forests (Sistla et al., 2016). With their multi-layered vegetation structure, homegarden serve as an important habitat for wild flora and fauna in these areas.

The land use systems in Sri Lanka at present are challenged as never being before with mounting concerns of environment on one hand and pressure of economic development on the other. Land use system not evaluate only on their ability to fulfill any single objective such as production of a selected commodity, but also on how best they fulfill the sustainability criteria. Over the years, the number and total area of homegardens in Sri Lanka have been increasing annually. The area under homegardens has been reported and widely quoted as 14.3% based on the reports of Food and Agricultural Organization (FAO, 2009). Therefore, the main objective of this research study was to identify dominant (timber, export agricultural and fruit) tree species and calculate diversity, species richness and evenness of plant species in Kandyan homegardens of Kandy and Kegalle districts.

Materials and methodsThe assessment of dominant plant species and diversity was conducted in year

2017 and 2018 in four Grama Niladhari divisions (Pilimathalawa, Gampola, Ambatenna and Alpitikanda) in Kandy district (Mid Country Wet zone) and four Grama Niladhari divisions (Hingula, Makehelwala, Hemmathagama and Warakapola) in Kegalle district (Low Country Wet zone). The area was known for its widespread homegardens and rich in species diversity. Total of 30 homegardens representing different age of occupation and sizes in each Grama Niladhari division was selected for the study. Diversity and dominance of fruit, timber and food/export agricultural/plantation crops over 5 cm diameter at breast height (dbh) were computed using the count and diameter



143

of individual plants using 5 m x 5 m quadrats in four replicates in randomly selected locations in each homegardens.

Tree species Dominance Importance Value Index (IVI)Importance value Index is a measure of species dominance in a particular location.

Importance Value Index (IVI) = Relative frequency + Relative Density + Relative Basal area

Where,

Relative Density = Density of a species / Total density of all species x 100

Relative Frequency = Frequency of a species / Total Frequency of all species x 100

Relative Basal area = Basal area of a species / Basal area of all species x 100

Tree diversity indicesA diversity index is a quantitative measure that reflects how many different

types (such as species) are in a dataset (a community), and simultaneously takes into account how evenly the basic entities (such as individuals) are distributed among those types.

Shannon Diversity Index (Shannon, 1948) sH = ∑ - (Pi * ln Pi) i=1

Where;

H = the Shannon diversity index

Pi = fraction of the entire population made up of species i

S = numbers of species encountered

∑ = sum from species 1 to species S

Simpson's Diversity Index (Simpson, 1949)

D = 1- ( Ʃn(n-1) )N(N-1)

Where;n = the total number of organisms of a particular species N = the total number of organisms of all species

144 Chandrapala et al.

Margalef Richness Index (Margalef, 1958)d = (S - 1) / Log (n)

Where; d = Margalef Richness IndexS = Total Number of Species n = Total Number of Individuals in the Sample

Margalef Richness Index measures the evenness with which individuals are divided among the species present.

Gini Coefficient (Corrado, 1912) N N

G =1 Ʃ Ʃ Iyi-yjI

2μN2

i=1 j=1

Where;G = Gini CoefficientN = Total number of individuals in all speciesYi = number of individuals in species iYj = number of individuals in species j

The Gini Coefficient measures the inequality among values of a frequency distribution. Gini Coefficient varies from zero to one. A Gini Coefficient zero expresses the perfect equality, where all values are the same (each species have same number of individuals). A Gini Coefficient one (100%) expresses maximal inequality (only one species in monoculture) among values.

Sorensen’s Similarity index (Sorensen, 1948)Ss = 2a / (2a + b + c) x 100

Where,Ss = Sorensen’s similarity indexa = Number of species common to both locationsb = Number of species unique to first locationc = Number of species unique to 2nd location

Sorensen’s similarity index measures the percentage similarity of species in two locations.

All the plant diversity values were computed using the biodiversity calculator available at www. alyoung.com web site.

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Results and discussionAccording to the Relative Importance Value of species, most dominant Fruit,

Timber and Food/Export agriculture/Plantation crops in Kandy and Kegalle districts (Combined value of four Grama Niladhari divisions in each district) were listed in table 1 and 2. Dominant fruit crop species and timber species in both districts were Banana and Jak tree respectively. Coconut was the dominant tree in the category of food/export agriculture/plantation crops in Kandy district. However, areca nut is the dominant tree species in Kegalle district in the same category. Although, there was a slight difference in dominancy, in a descending order of dominancy, first ten species of fruit, timber and food/export agriculture and plantation crops category were more or less similar in both districts. As there were similarity in agro-ecology and soil type in both districts, there may be a tendency of dominancy of similar species. In addition, most of the species were deliberately planted depending on the requirement of family members and marketing potentials. Therefore, there may be a tendency of planting popular crop and timber species in the region. There was also a tendency of removing less economic value tree species from homegardens and accommodating more valuable tree species disrupting the natural selection process of species. Easy access to the planting materials of some species might have played an important role in species dominancy. Therefore, there may not be the most ecologically adapted trees in the homegardens. The dominancy of species in homegardens might not a natural process in most cases but deliberate inclusion or retention and assisted regeneration of useful species.

Table 1. Importance Value Index (IVI) of species in homegardens in Kandy districtFruit IVI Timber IVI Food/plantation

and Export agriculture crops

IVI

Banana (Musa x paradisiaca)

24.6 Jak (Artocarpus heterophyllus)

22.1 Coconut (Cocos nucifera)

24.6

Guava (Psidium guajava)

19.5 Mahogany (Swietenia macrophylla)

18.3 Areca nut (Areca catechu)

19.7

Mango (Mangifera indica)

18.5 Ginisapu (Michelia champaca)

17.2 Coffee (Coffea Arabica)

17.7

Avocado (Persea Americana)

6.6 Kenda (Macaranga peltata)

16.8 Nutmeg (Myristica fragrance)

16.4

Rambutan (Nephelium lappaceum)

6.1 Tuna (Toona sinensis)

12.3 Clove (Syzygium aromaticum)

14.3

Papaya (Carica papaya)

5.9 Hawarinuga (Alstonia macrophylla)

9.5 Kithul (Caryota urens)

7.6


Fruit IVI Timber IVI Food/plantation and Export

agriculture crops

IVI

Anona (Annona muricata)

4.3 Halmilla (Berrya cordifolia)

4.2 Breadfruit (Artocarpus nobilis)

4.1

Ambaralla (Spondias dulcis)

4.0 Albizzia (Falcataria moluccana)

3.6 Rubber (Hevea brasiliensis)

3.4

Pomogranate (Punica granatum)

3.9 Lunumidella (Melia azedarach)

3.0 Cocoa (Theobroma cacao)

4.4

Durian (Durio zibethinus)

3.1 Teak (Tectona grandis)

2.8 Curry leaves (Murraya koenigii)

3.7

Table 2. Importance Value Index (IVI) of species in homegardens in Kegalle districtFruit IVI Timber IVI Food/plantation/

Export agriculture crops

IVI

Banana (Musa x paradisiaca)

32.9 Jak (Artocarpus heterophyllus)

28.1 Areca nut (Areca catechu)

32.7

Mango (Mangifera indica)

29.5 Mahogany (Swietenia macrophylla)

16.3 Coconut (Cocos nucifera)

27.7

Guava (Psidium guajava)

10.2 Hawarinuga (Alstonia macrophylla)

7.7 Clove (Syzygium aromaticum)

12.5

Rambutan (Nephelium lappaceum)

6.3 Kenda (Macaranga peltata)

6.8 Coffee (Coffea robusta)

11.4

Avocado (Persea Americana)

5.5 Kududavula (Neolitsea cassia)

5.2 Kithul (Caryota urens)

9.6

Jambu (Syzygium jambos)

4.1 Tuna (Toona sinensis) 4.2 Nutmeg (Myristica fragrance)

8.6

Ambaralla (Spondias dulcis)

3.6 Albizzia (Falcataria moluccana)

3.7 Breadfruit (Artocarpus nobilis)

2.1

Papaya(Carica papaya)

3.1 Ginisapu (Michelia champaca)

3.3 Cocoa (Theobroma cacao)

1.4

Durian (Durio zibethinus)

3.3 Lunumidella (Melia azedarach)

3.1 Curry leaves (Murraya koenigii)

1.2

Anona (Annona muricata)

2.8 Gadumba (Trema orientalis)

2.6 Rubber (Hevea brasiliensis)

1.1

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Table 3. Diversity and dominance of fruit crops in HomegardensParameter Location

Kandy KegalleAmba* Gamp Pili Alpi Hemm Hing Wara Make

Number of species 31 27 28 27 27 28 20 23Simpson’s diversity index 0.872 0.891 0.797 0.897 0.796 0.889 0.862 0.914Shannon diversity index 2.6 2.65 2.28 2.68 2.27 2.58 2.43 2.76Margalef richness index 4.66 4.14 4.49 4.26 4.33 4.17 4.15 4.05Gini coefficient 0.652 0.592 0.690 0.572 0.69 0.541 0.606 0.456Sorenson’s Similarity Index

84.75%

Amba* = Ambatenna, Gamp = Gampola, Pili = Pilimathalawa, Alpi = Alpitikanda, Hemm = Hemmathagama, Hing = Hingula, Wara = Warakapola, Make = Makehelwala

Table 4. Diversity and dominance of Export agriculture crops in HomegardensParameter Location

Kandy KegalleAmba* Gamp Pili Alpi Hemm Hing Wara Make


80%


Table 5. Diversity of timber species in homegardensParameter Location

Kandy KegalleAmba Gamp Pili Alpi Hemm Hing Wara Make


61.9%



Table 6. Diversity of all species in HomegardensParameter Location

Kandy KegalleAmba Gamp Pili Alpi Hemm Hing Wara Make

Number of species 67 50 52 51 54 52 40 49Simpson’s diversity index 0.930 0.90 0.86 0.906 0.896 0.892 0.851 0.938Shannon diversity index 3.12 2.96 2.43 2.88 2.75 2.39 2.31 3.21Margalef richness index 8.50 7.00 6.1 6.57 4.53 5.63 4.82 6.95Gini coefficient 0.74 0.69 0.57 0.71 0.56 0.59 0.51 0.54


In this study, 20 to 31 fruit crop species, 9 to 15 export agriculture crop species and 9 to 21 timber tree species were found in 240 homegardens studied in eight Grama Niladhari divisions in Kandy and Kegalle districts. Out of eight Grama Niladhari divisions studied, Makehelwala in Kegalle district recorded the highest species diversity of fruit crops, timber trees and overall species according to the Simpson’s and Shannon diversity indices (Table 3, 5, and 6.). However, highest species diversity of food/export agriculture and plantation crops was recorded in Ambatenna GN division in Kandy districts, may be due to the favorable micro climatic condition prevailed in the area for food/export agriculture/plantation crops (Table 4). Compared to the natural systems like natural forests, there are number of factors affecting to the diversity and dominance of species in homegardens. Apart from the soil and agro-ecology, preference of households play an important role in species diversity as the majority of species were selected deliberately according to their choices. According to the diversity indices, fruit crops were the most diverse species in both districts and except in Pilimathalawa and Alpitikanda, food/export agriculture/plantation crops was in lowest diverse category. In addition, as there was a tendency of planning those species as monocultures, even in homegardens may also lead to the low diversity of food/export agriculture/plantation crops in homegardens.

Highest species richness (Margalef richness index) of fruit crops, timber trees and overall species was recorded in Ambatenna Grama Niladhari division of Kandy district. However, highest species richness of food/export agriculture/plantation crops was recorded in Hemmathagama GN division of Kegalle district. Highest species richness in homegardens was recorded in Ambatenna GN division (67 species) of Kandy district (Table 5) was comparable to the species richness of homegarden species in Tanzania (56 species) (Fernandes et al., 1985) and Kerala state, India (71 species)

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(Chandrashekara, 2009). However, relatively low tree species richness (27 species) was recorded by Jacob and Alles (1987) in homegardens of Kandy, Sri Lanka which was relatively lower than the species richness values observed in present study in both Kandy and Kegalle Districts.

Lowest overall species uniformity (Lowest Gini coefficient) of species (Fruit, food/export agriculture/plantation crops, timber trees and overall species) was also recorded in Makehelwala grama niladhari division of Kegalle district, indicating the highly distributed individuals among the species in the area.

According to the Sorenson’s Similarity Index, there were 84.75% similarity of fruit crops, 80% similarity of Food/Export agriculture/Plantation crop and 61.9% similarity of timber species in homegardens between Kandy and Kegalle districts (Table 3, 4, and 5).

ConclusionBanana, Jak and Coconut were the dominant fruit, timber and food/export

agriculture/plantation crop species, respectively in homegardens in Kandy district. Although, dominant fruit and timber species in Kegalle district was same as in Kandy district, Areca nut was the dominant food/export agriculture/plantation crop species in Kegalle district. Highest overall species richness and diversity was recorded in Ambatenna GN division of Kandy district.

ReferencesChandrashekara, U.M. Tree species yielding edible fruit in the coffee-based home-gardens of

Kerala, India: Their diversity, uses and management. Food Secur. 2009. 1: 361–370.

Corrado, G. 1912. Variability and Mutability. Journal of the Royal Statistical Society. 76 (3): 326 – 327.

FAO. 2009. Sri Lanka forestry sector outlook study by Forest Department. Working Paper No. APFSOS II/WP/2009/29. FAO, Regional Office for the Asia and the Pacific, Bangkok, Thailand.

Fernandes, E.C.M., A. Oktingati and J. Maghembe. 1985. The Chagga home-gardens: A multistoried agroforestry cropping system on Mt. Kilimanjaro (northern Tanzania). Agrofor. Syst. 2: 73–86.

Jacob, V.J. and W.S. Alles. 1987. Kandyan gardens of Sri Lanka. Agrofor. Syst. 5: 123–137.

Kumar, B.M. and P.K.R Nair. 2004. The enigma of tropical home-gardens. Agrofor. Syst. 61(62): 135–152.

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Margalef, R. 1958. Information Theory in Ecology. International Journal of General Systems. 3: 36 – 71.

Nair, P.K. 1993. Classification of agroforesty systems; Kluwer Academic Publishers: Dordrecht, the Netherlands; Boston, MA, USA; London, UK. 73.

Shannon, C.E. 1948. A mathematical theory of communication. The Bell System Technical Journal, 27: 379–423.

Simpson, E.H. 1949. "Measurement of diversity," Nature. 163:688.

Sistla, S.A., A.B. Roddy, N.E. Williams, D.B. Kramer, K. Stevens and S.D. Allison. 2016. Agroforestry practices promote biodiversity and natural resource diversity in atlantic Nicaragua. PLoS ONE. 11: 1–20.

Sorensen, T. 1948. A method of establishing groups of equal amplitude based on similarity of species and its application to analyses of the vegetation on Danish commons. Kongelige Danske Videnskabernes Selskab. 5 (4): 1–34.

Chandrapala et al.

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Effect of coloured polythene mulch on growth, yield and quality of carrot var. Lanka carrot

I.C.S. Edirimanna, J.M.D.D.E. Jayamanne, H.M.V.S. Dharmasena, A.M.R. Darshana and S.M.U.I. Samaraweera


IntroductionCarrot (Daucus carota L.) is an important vegetable, which is ranked third

among the succulent vegetables in the world production (Yamaguchi, 1983). Carrots, which belongs to the family Apiaceae is a biennial and is usually cultivated as an annual crop in the tropics (De Lannoy, 2001). Different coloured natural soils and plant residues can reflect a wide range of photosynthetic and morphogenic light to influence yield and quality of growing plants and most influential colors of morphogenic light appear to be far red (FR), red (R) and blue. In a field experiment where different colors of soil covers were used to reflect lower FR/R ratios to that of incoming sunlight favored below ground growth (Kasperbauer, 1992). Therefore, the objective of the present study was to determine whether the colour of light reflected from the mulch to growing carrot leaves would affect growth, yield and quality of edible roots, (Pale colour, hard core and low taste) of var. Lanka Carrot.

Materials and methodsTwo successive field experiments were conducted at the Regional Agriculture

Research and Development Centre, Bandarawela in 2016 Yala and Maha 2016/17 seasons. In each season carrots were planted in raised beds (2.5 m x 1.1 m) with 25x10 m spacing and experiment was arranged as a Randomized Complete Block Design (RCBD) with 03 replicates. Five different colour polythenes (Gauge 100) were used as treatments, T1-Yellow, T2-White, T3-Transparent, T4-Blue, T5-Black and T6-Open field (Control). Plant growth, yield and root quality parameters were recorded from six randomly selected plants at harvest. Root colour was noted using visual scale and Munson’s color chart and T.S.S was notes using ATAGO, MASTER-10α (Brix 0-10%) hand held refractometer.

Results and discussionThe results of the study are given in Figure 1 and 2, crop growth characters

(Plant height and Number of leaves) were inconsistently related with two field seasons.



152 Edirimanna et al.

Figure 1. The effect of color polythene mulch on plant height of var. Lanka carrot

Figure 2. The effect of colour polythene mulch on leaf numbers of var. Lanka carrot

As depicted in Table 1 and 2, in both seasons the highest root/ shoot ratio was recorded in T1. But in Yala 2016 it was not significantly difference with control. In Yala 2016, the highest single root weight was observed in T6 and T3, where T1, T2 and T4 were observed significantly similar results with them.

Total yield in Yala 2016 was not significantly different among the treatments. Whereas in Maha 2016/17, highest total yield was observed in T5 (black). In Yala 2016 significantly highest marketable yield was recorded by T1 compared to control (T6). Further in Maha 2016/17, this difference was significant compared to all others, except T4 (Blue).

Table 1. The effect of colour polythene mulch on single root weight and root shoot ratio of var. Lanka carrot

Treatments Weight of single root (g) Root/Shoot ratioYala 2016 Maha 2016/17 Yala 2016 Maha 2016/17

T1–Yellow polythene 98.8ab 111.8b 2.6a 4.1a

T2–White polythene 95.5ab 156.6a 2.1abc 2.4b

T3–Transparent polythene 107.4a 142.1a 2.3abc 2.5b

T4–Blue polythene 92.4ab 134.3ab 2.5ab 2.7b

T5–Black polythene 86.7b 160.2a 2.4abc 2.3b

T6 – Open 108.6a 158.3a 2.0c 2.5b

CV% 23.18 21.8 20.03 27.7 Means having different letters differ significantly at 5% probabilityMeans with different letters (in superscripts) are significantly different at p=0.05

Plan

t hei

ght (

cm)

Plan

t hei

ght (

cm)

Treatments Treatments

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Table 2. The effect of colour polythene mulch on yield parameters of var. Lanka CarrotTreatments Total yield (mt/ha) Total marketable yield

(mt/ha)Yala 2016 Maha 2016/17 Yala 2016 Maha 2016/17

T1–Yellow polythene 29.8a 23.4ab 22.7a 22.9a

T2–White polythene 27.2a 14.2b 15.3ab 11.2bc

T3–Transparent polythene 29.0a 12.2b 18.4ab 10.4bc

T4–Blue polythene 30.1a 22.1ab 18.7ab 19.6ab

T5–Black polythene 31.4a 30.6a 18.5ab 12.7bc

T6- Open 30.6a 24.8ab 14.1b 9.6c

CV% 16.39 26.52 20.6 22.82 Means having different letters differ significantly at 5% probabilityMeans with different letters (in superscripts) are significantly different at p=0.05

The results of both tested seasons revealed that, the colour of polythene mulch were not significantly affected on root length. In Maha 2016/17 root circumference was significantly higher in T1 compared to control, but in 2016 was not observed significantly different among the treatments. As shown Table 3 core diameter was inconsistently related over two seasons.

Table 3. The effect of colour polythene mulch on root characters of Var. Lanka CarrotTreatments Root length (cm) Root circumference

(cm)Core diameter

(cm)Yala 2016

Maha 2016/17

Yala 2016

Maha 2016/17

Yala 2016

Maha 2016/17

T1–Yellow polythene 14.9a 18.8a 12.2a 4.1a 1.3b 1.4c

T2–White polythene 14.3a 18.5a 12.0a 2.4b 1.4b 2.3a

T3–Transparent polythene 14.5a 17.6a 13.0a 2.5b 1.5ab 1.9b

T4–Blue polythene 14.2a 18.5a 12.6a 2.7b 1.4b 1.9b

T5–Black polythene 14.1a 19.3a 12.6a 2.3b 1.5ab 1.9b

T6 – Open 14.2a 19.3a 13.2a 2.5b 1.7a 2.1ab

CV% 14.15 13.4 14.12 27.7 22.93 21.05Means having different letters differ significantly at 5% probabilityMeans with different letters (in superscripts) are significantly different at p=0.05

In Yala 2016, highest total soluble solids value in T3. In Maha 2016/17 , highest value was recorded in T1 compared to control (T6). In Yala 2016, the highest root colour was observed in T1, where T2, T3, T4 and T6 were not significant to them. In 2016/17 season highest root colour was recorded in T1 and T3 compared to control. (Table 3). Antonious and Kasperbauer (2002) have also observed yellow surfaces reflected more photosynthetic light and lower FR/R ratio than blue, green and red surfaces. Other

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spectral differences in reflection from yellow apparently had less influence than PPF and FR/R ratio on accumulation of ß-carotene in the carrot roots.

Table 4. The effect of colour polythene mulch on quality parameters of var. Lanka carrotTreatments Brix (T.S.S) Colour

Yala 2016 Maha 2016/17 Yala 2016 Maha 2016/17T1-Yellow polythene 6.7ab 7.2a 3 (2.8a) 4 (4.2a)T2-White polythene 6.8ab 6.6ab 3 (2.6ab) 3 (2.4b)T3-Transparent polythene 6.9a 6.3b 3 (2.5ab) 4 (3.8a)T4-Blue polythene 6.4ab 6.7ab 3 (2.8ab) 3 (2.6b)T5-Black polythene 6.2ab 6.9ab 2 (2.1b) 3 (2.7b)T6 - Open 6.1b 6.1b 3 (2.2ab) 3 (2.7b)CV% 13 15.4 20.84 16.3

Means having different letters differ significantly at 5% probabilityMeans with different letters (in superscripts) are significantly different at p=0.05Scale used for colour measurements - (Based on colour chart) 1-169B, 2-169C, 3-169D, 4-170A, 5-170B, 6-170C, 7-170D

ConclusionBased on the results, yellow color polythene mulch was found to increase total

marketable yield with high quality dark orange colour roots. The information gathered in this research will useful to maintain surface colour of soil to improve yield and quality parameters of different crops.

ReferencesAntonious, F.J. and M.J. Kasperbauer. 2002. Color of light reflected to leaves modifies nutrient

content of carrot roots. Journal of Crop science. 42: 1211-1216.

De Lannoy, G. 2001. Carrot. In: Crop production in Tropical Africa. R.H. Raemaekers (ed.) Directorate General for International Coorporation, Brussels,Belgium. 480-485.

Kasperbauer M.J. 1992. Phtochrome regulation of morphologies in green plants: From the Beltsville Spectrograph to colored mulch in the field. Photochem. Photobiol. 56: 823 – 832.

Yamaguchi, M. 1983. World vegetables, principles production and Nutritive values. Van Nostrand Reinhold, New York. 240-246.

Edirimanna et al.

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Cost benefit analysis on establishing of machinery hiring out centre

K.G.C.D.B. Wijesinghe, G.L. Nagahawaththa, R.B.T.M. Radeniya and D.M.B. Priyadarshani

Socio economics and Planning Centre, Department of Agriculture, Sri Lanka

IntroductionAccording to the Department of Census and Statistics (DCS) agriculture labour

has been reduced over the years and at present it is 25.5% (DCS, 2018). Mechanization will be a good solution for the problem of youth withdrawal from agriculture and establishment of machinery hiring centres as initiated by Yaya 2 programme will address this issue effectively. This study evaluates the financial and economic feasibility for one machinery hiring out centre. Study shows that machine usage has been increased over the years from 1980 to 2013 from 20% to 55%. The majority is imported machinery and tractors of which number of registered tractors was 343, 263 by 2015 (Abeyratne, 2017). In addition, Study shows low usage of machinery due to high capital cost. Drivers for mechanization identified as high cost of labour, unwillingness of youth for conventional agriculture operations and aging of population. Discounting rate for the project was calculated using weighted average cost of capital (WACC) of equity and loans (Farber et al., 2006). Equity cost of capital was calculated using the capital assets pricing model (CAPM) (Kisman and Shintabelle, 2015). Equity risk for Sri Lanka obtained as 12.2% (Country Default Spreads and Risk Premiums, 2019)

Materials and methodsMachinery hiring out centres provide the timely service by hiring out its

owned machinery to farmers at reasonable rate and consist of machinery used for land preparation, harvesters, processors etc. (Sidhu and Vatta, 2012). For this study technical information (operating time per batch, operating cost, useful life of the machines and maintenance cost) and prices were obtained from Farm Mechanization Research Centre (FMRC) Mahailluppallama. Total project investment worth is Sri Lankan Rupees (LKR) 16 million. Salary and wages were obtained from labour demand survey results (DCS, 2017) and 25% incentive was considered for Employee Provident Fund (EPF) and Employee Trust Fund (ETF) deductions. Machinery hiring out rate was obtained from machinery cost obtained from Cost of Cultivation (COC) survey reports of Department of Agriculture (COC, 2017). Financial analysis consists of financial statement analysis,



156 Wijesinghe et al.

financial measures of project worth and sensitivity analysis and economic analysis consist of economic worth of the project. Project economical life was assumed to be 10 years (Gryglewicz et al., 2008) and for economic analysis Social Discount Rate (SDR) used as 12% in India (ADB, 2013) and financial prices were converted to economic prices using shadow prices (Martin, 2004). Subsidized agriculture loan scheme “jaya isura” at 6.75 rate with grace period of 1 year and repayment period of 7 years was used as the financing option.

Results and discussionIn project financial analysis, income statement of the project shows profit of

rupees 27 million annually, cash flow statement shows high liquidity and balance sheet statement shows 277 Mn of strong financial position at the end of project economic life. Financial measures of project worth is shown in Table 1.

Table 1. Financial measures of project worth at 8.8% cost of capitalMeasure Without finance With finance

Internal Rate of Return (IRR) 23% 65%Pay Back Period (PBP) in years 4.37 1.54Net Present Value (NPV) (LKR ‘000) 9,427 10,532Net Present Value of benefits (NPV b) (LKR ‘000) 231,721 240,912Net Present Value of costs (NPVc) (LKR ‘000) 222,294 230,380Benefit/ Cost (B/C) Ratio 1.04 1.05

According to above results NPV of the project is positive and calculated IRR is higher than the cost of capital ensures the profitability of the project. In addition, higher NPV value and IRR in financing option show mixed financing option is more profitable over equity financing. Sensitivity analysis results shown in Table 2, product prices are sensitive than the input prices. In addition, project will not be profitable under the scenario 3 with changing all prices unfavourably. Economic analysis results show that the project is economically feasible (Table 3).

Table 2. Project sensitivity at 5% change in pricesItem

Sensitivity 1 Sensitivity 2 Sensitivity 3

Without loan

With loan

Without loan

With loan

Without loan

With loan

IRR 6.3% 6.0% 5.4% 4.3% -11.9% -18.4%PBP 15.9 16.8 18.4 23.0 -8.4 -5.4NPV (LKR ‘000) -1,688 -987 -2,160 -1,514 -13,274 -13,033B/C Ratio 1.0 1.0 1.0 1.0 0.9 0.95

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Table 3. Economic project worth at SDR 12%Measure Value

Economic Internal Rate of Return (EIRR) 34%Pay Back Period (PBP) in years 2.95Economic Net Present Value (ENPV) (LKR ‘000) 11,843Net Present Value of benefits (NPV b) (LKR ‘000) 195,954Net Present Value of costs (NPVc) (LKR ‘000) 184,111Economic Benefit/ Cost (B/C) Ratio 1.06

ConclusionSince project generates positive net financial benefits and net social benefits,

it is concluded that the project investment is financially and economically viable. Therefore, it is recommended to establish machinery hiring out centres at financial and economic platform.

AcknowledgementContribution given by the FMRC staff and engineering division staff by

providing technical information is highly appreciated in this exercise.

ReferencesAbeyratne, F. 2017. Small farm agriculture mechanization in Sri Lanka: its growth and

constraints: https://www.slideshare.net/essp2/small-farm-agriculture-mechanization-in-sri-lanka-its-growth-and-constraints-81495679 (Accessed on 18.08.2019)

Asian Development Bank (ADB). 2013. Cost Benefit Analysis for Development. [online]. https://www.adb.org/sites/default/files/institutional-document/33788/files/cost-benefit-analysis-development.pdf.

Cost of cultivation survey reports (COC). 2017. Department of Agriculture

Country default spreads and risk premiums. January 2019. http://pages.stern.nyu.edu/~adamodar/New_Home_Page/datafile/ctryprem.html (Accessed on 04.01.2019)

Farber, A., R. Gillet and A. Szafarz. 2006. A general formula for the WACC: https://www.ssrn.com/abstract=898420 (Accessed on 18.08.2019)

Gryglewicz, S., J.M.K. Huiseman and P.M. Kort. 2008. Finite project life and uncertainty effects on investment: https://personal.eur.nl/gryglewicz/files/finlife.pdf (Accessed on 18.08.2019)

Kisman Z. and R.M. Shinatabelle. 2015. The validity of capital assets pricing model (CAPM) and arbitrage pricing theory (APT) in predicting the return of stocks in Indonesia stock exchange 2008-2010: files.aiscience.org/journal/article/pdf/70200023.pdf (Accessed on 17.08.2019)

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Martin A.L. 2004. Shadow exchange rates for project economic analysis: towards improving practice at the Asian development bank, ADB: https://www.adb.org/sites/default/files/publication/29856/tn-11-shadow-exchange-rates.pdf (Accessed on 08.01.2019)

Sidhu R.S. and K. Vatta. 2012. Improving economic viability of farming: a study of cooperative agro machinery service centres in Punjab: https://pdfs.semanticscholar.org/bb2c/464397124cc3f00d3dc0ba6a64da695f1ade.pdf (Accessed on 17.08.2019)

Wijesinghe et al.


**This abstract has been presented as a poster at the Annual Symposium of Department of Agriculture, 2019

Performance and economic returns of cultivating reed plants (Cyperus corymbosus) under rainfed conditions in paddy fields

of Wet zone for traditional craft weaving industry in Sri Lanka

G.D.A. Priyantha1, I. Madhavi2 and J.N. Silva1

1Regional Rice Research and Development Centre, Bombuwala, Sri Lanka,

2Mahee Soba Environmental Organization, Handapangoda, Sri Lanka

AbstractTraditional craft weaving industry based on rush and reed plants, make use of

different types of plant materials. The most commonly used local reed plant is known as Gallehe (Cyperus corymbosus) and it is traditionally considered a good quality weaving material. Rush and reed plants (more than 12 species) are raw materials for many traditional and modern finished products of mats, baskets, hats, ropes, wall hangers, sleepers, and also eco friendly wrappings of some commercial products. The demand for rush and reed products is increasing at a rapid rate in the local and export market. Presently the minimum whole sale price for 1 kg of dry reed is Rs. 250. The natural habitats of C. corymbosus are in the declining trend. A research was conducted to study the feasibility and economic returns of growing Cyperus corymbosus in the agro ecological zone of WL2a under rainfed condition. Experimental design was RCBD with two replicates and trial was established in Maha 2016/17 season as two constructed reed beds with plot area of 10 m2. The results reveal that time for harvesting of mature reed of C. corymbosus was 91 days while flowering initiated at 42 days under the tested rain fed condition. Mean height, tiller number, leaf number and leaf length were 54.4, 3, 2 and 5.7 cm, respectively. The mean fresh weight of 1.875 kg/m2 of reed was harvested at least every 90 days under the tested rain fed conditions. Shade drying of reed harvest results in mean dry weight of 0.61 kg/m2 with an economical gain of Rs, 152.5 kg/m2 as gross return by reed harvest at the rate Rs. 250 per 1 kg of dry reed which is suitable for weaving.

Key words: Environmental conservation, Reed, Rush, Women labour



Stump suckers as planting materials in cabbage cultivation

N.S. Senanayake, K.P. Somachandra, T.K.A.I. Hadji, K.D.M. Kularathna and A. Dharmasena


AbstractCabbage (Brassica oleracea var. capitata) is a popular vegetable crop cultivated

in Up Country Intermediate zone as well as in Dry zone areas of Sri Lanka. Cabbage is solely propagated by seed and Sri Lankan farmers totally depend on exotic hybrid varieties and imported seeds. Annually, Sri Lanka imports 1,607 kg of cabbage seeds spending Rs. 120.8 Mn foreign exchange. The cost of production (COP) of cabbage is Rs. 510,088/ha (Anon., 2017) and most farmers (53%) used to purchase seedlings from commercial nurseries. They spend reasonable sums of money (Rs. 65,519.00/ha) on planting materials which is nearly 12.8% of COP. Therefore, an alternative method of propagation of cabbage will have added benefits on cabbage cultivation. Though it is possible to propagate cabbage through stump suckers, the published information on the technique is scarce in Sri Lanka as well as worldwide. Therefore, this preliminary study was undertaken to determine the possibility for use of cabbage stump suckers as alternative planting material. The experiment was conducted in 2018 at the Regional Agriculture Research and Development Centre, Bandarawela. Thirty cabbage heads were harvested at the correct maturity stage and mature leaves remained on the stumps were removed leaving bare stump. Then these stumps were kept in the field to produce suckers. Two to three weeks old suckers were removed and established in a nursery. The rooted suckers were established in the field and maintained following Department of Agriculture recommendations up to head formation and maturity. Number of suckers produced by a stump, time taken from transplanting to maturity of suckers, canopy diameter of plant at the head formation and head weight were measured. Results revealed that each stump can produce 15 suckers within two weeks. After two weeks in the nursery, suckers were ready for transplanting and it was two weeks early compared with seedlings. Stump suckers produced 0.850 kg to 1.250 kg cabbage heads and average head weight was 1.060 kg. It was significantly lower compared to the cabbage heads obtained from conventional seedlings (1.960 kg). There are many other advantages in this technique. Stump suckers presently consumed as a leafy vegetable can be used to produce planting materials with no added cost.

Key words: Alternative planting material, Cabbage, Propagate, Stump suckers



Developing a protocol for production of planting materials of apple (Malus domestica) by using tissue culture and graftting

L.G.I. Samanmalie1, E.G.A.R. Mallika1, K.G.G. Indika1, S. Widyaratne1 and H.M.S. Bandara2

1Plant Virus Indexing Center, Homagama, Sri Lanka 2National Fruit Crop Conservation Center, Kundasale, Sri Lanka

AbstractApple is one of the most important temperate-zone fruit crop in the world.

According to market report Sri Lanka imported USD 16 billion worth of apple in 2016. In Sri Lanka some locations have a suitable climatic condition for apple cultivation. There are apple cultivations that are being maintained in Kundasale and Bandarawela by the Department of Agriculture Sri Lanka. 100-150 apple fruits per plant are harvested from apple trees in the National Fruit Crop Conservation Center at Kundasale. There is a big demand for planting material of apple. However, production of planting material is found to be difficult. Hence a protocol development for apple planting material is very important as a solution to the above problem. Micro propagation technique for rootstock has already been developed. In this research, an apple planting material production procedure was developed with in-vitro propagated apple rootstocks and scion from fruit beard apple plants. Shoot proliferation was carried out in Murashige and Schooge media (MS) containing 4 mg/l of Benzyl Amino Purine and rooting of micro shoots were done in MS media containing 2 mg/l concentration of Indol Butric Acid. The rooted apple plantlets were grown up to 25 cm in sterilized coir pellets with liquid fertilizer media in a single propagator. Plantlets were transplanted in plastic pots containing top soil, sand and compost 1:1:1 ratio. Plants were grown in net house condition with weekly application of liquid fertilizer. Plants with matured stems were cut and budding process was carried out. The scions were taken from a selected field planted apple plant. 10 cm long scions were taken from field planted apple plants with suitable stem size for root stocks. Budded plants were placed in a net house with a single propagator. After 3 weeks, plants were observed and removed from the propagators. At the end of two months plants were well grown and a 90% budding success rate was observed. This method can be used as an effective method for the production of planting material in apple. Most of the apple cultivating countries use this technology for apple planting material production.

Key words: Apple, Planting material, In-vitro propagation



Value added products from pumpkin (Cucurbita maxima) to reduce post harvest losses and increase farmer income

D.N. Hettiarachchi, D.L.C.N. Hitigedara, H.M.D.K. Jayarathna, R.A.Wijerathna and S.M.A.C.U. Senarathne

Food Research Unit, Gannoruwa, Sri Lanka

AbstractPumpkin is a very nutritious major vegetable widely grown in Sri Lanka. Due

to surplus in the season, farmers face a severe problem in selling pumpkins as price becomes very low. Hence a big amount of harvest is wasted causing a big issue in agriculture sector every year. To solve this problem it is very important to develop technologies to preserve pumpkin, to minimize loss during the season and use them during off season. Further, introducing value added products to popularize pumpkin and increase the consumption is needed. Therefore, this study was aimed to develop technologies to preserve pumpkin and introduce naval delicious value added products to enhance farmer income and reduce post harvest losses. Dehydration of pumpkin was done using hot-air dryer (Phoenix, Japan). Washed, peeled and grated pumpkin was pre-treated and dehydrated at 55 0C for 8 hours. Then half of dehydrated product was ground and sieved to make flour and other half was incorporated to in foods as unground form. Further flour and unground dehydrated pumpkin were packed in clean sterilized glass jars and in 300 gauge polypropylene respectively and tested for keeping quality. Physico-chemical parameters including color and moisture percentage were measured. Pumpkin flour was tested in bread, bun and biscuit making for possible introduction to bakery industry. Use of unground form in noodles industry, fried rice and other food items was tested. Fresh pumpkin was used to prepare fresh juice, ready to serve drinks, chutney, candy and incorporated in to rotti, pittu, fried rice, noodles, kottu and etc. Sensory attributes of all food products were highly acceptable when tested. Therefore, use of dehydrated and fresh pumpkin in various value added products can boost selling of pumpkin, reduce post harvest loss and enhance farmer income.

Key words: Dehydration, Pumpkin, Value added products



Identification and characterization of soft-rot causing pathogen in Aglonema maria; A key exporting ornamental plant in

Sri Lanka

M.H.A.D. Subhashini1, C.M. Nanayakkara2, L.C.K. Senaratne1 and D. Piyatissa1

1National Plant Quarantine Service, Canada Friendship Road, Katunayake, Sri Lanka

2Faculty of Science, University of Colombo, Sri Lanka

AbstractSoft rot of Aglonema maria is one of the most destructive diseases occurring

in serious form in export nurseries, affecting the quality which leads to reduction in quantities to be exported. Some of the most vulnerable host plants are Philodendron spp., Chrysanthemum spp., Dianthus caryophyllus and Euphorbia pulcherrima etc. Therefore, this study was aimed at identifying the pathogen associated with soft rot in Aglaonema maria by using morphological, physiological and bio-chemical methods. In this situation, rapid identification of an unknown pathogen was necessary and plants with the indication of characteristic water soaked, necrotic lesion on leaves and a distinctive foul-smelling odor associated with the rot or blight were collected from export nurseries for isolation of the pathogen. The standard protocol was followed for isolation. Potato Dextrose Agar (PDA) and Nutrient Agar (NA) medium were used as basic culture media and plates were incubated for 2-3 days at 28 0C. Individual colonies were further transferred and pure cultures were maintained on NA plates. For identification and confirmation of suspected bacteria, a serious of morphological, biochemical and physiological tests, which were specific to Erwinia chrysanthemi were performed. All the tests were replicated thrice. Two selective media, such as Crystal Violet Pectate medium (CVP) and Nutrient agar with 1% Glycerol (NGM) were used to observe morphology. In addition, a series of biochemical tests were performed namely, use of 3% KOH, carrot test, gram reaction, growth at 36 0C, Nitrate Reduction, Gelatin liquefaction, Oxidative Fermentative test, Indole production test, Methyl red test, Citrate utilization and Sugar Fermentation tests, sensitivity to erythromycin (50 μg/ml) and oxidase test. The Koch’s postulation was conducted to prove pathogenicity. On NA young colonies were circular, convex, smooth and entire and after 3-4 days, margin of colonies resembled a fried egg, which later took a feathery appearance. A clear zone appeared around produced colonies where the substrate had degraded on CVP media.



The pathogen had grown well on the NGM medium developing a characteristic dark-blue pigment diffusible in the medium and easily distinguishable from other Erwina spp. with the help of 3% KOH and gram reaction, the bacterium was proved as gram negative and all other tests were positive for E. chrysanthemi except Maltose and Oxidase tests, which imparted negative results. The pathogen was identified as Erwinia chrysanthemi on the basis of morphological and biochemical studies.

Key words: Biochemical tests, Erwinia chrysanthemi, Morphology, Soft rot



Pumpkin incorporated nutritionally rich burger bun

H.B. Sasiprabha1, S.P. Rebeira1, R.M.S.K. Ranathunga2, K.G.U.K. Koongahage1 and A.D. Amaraweera1

1Food Research Unit, Gannoruwa, Sri Lanka2University College of Anuradhapura, University of Vocational Technology,

Anuradhapura, Sri Lanka

AbstractBun is a ready to eat food consumed by people and also they are adapted to

such easy foods with their busy life styles. Bun is usually made using wheat flour, which contains mainly carbohydrate but lack of other nutrients. Therefore, fortification of such foods with a source of high nutritional value is important to overcome nutritional imbalance of consumers. Research are found in literature on bakery products fortified with other grains and pulses however, very few bakery products are fortified with vegetable pulp or flour. Pumpkin is a nutrient source which is rich in β carotene, vitamin A and having considerable content of other vitamins and minerals. Last few years, considerable over production of pumpkin was recorded arising the timely need of value addition on pumpkin. This study was undertaken to develop value added bakery product; Burger bun incorporating pumpkin flour or pumpkin pulp in addition to wheat flour. As basic ingredients, wheat flour, sugar, yeast, bread improver, salt, margarine and milk powder were used with different levels of pumpkin flour or pumpkin pulp. Two levels of pumpkin pulp (15%, 25%) and two levels of pumpkin flour (10%, 20%) were selected through preliminary trials. Sensory evaluation was conducted for appearance, colour, aroma, taste, texture and overall acceptability using 7- point hedonic scale test to select best level of pumpkin pulp / flour. Burger bun incorporated 25% of pumpkin pulp recorded to have significantly higher sum of rank with respect to overall acceptability and texture. The highest sum of ranks for appearance, colour and taste was recorded by 25% pumpkin pulp incorporated bun. But, there was no significant difference at 0.05 probability level. According to the results, it can be concluded that 25% of pumpkin pulp can be incorporated in burger buns to improve the nutritional value and sensory acceptability.

Key words: Burger bun, Nutritional value, Pumpkin flour, Pumpkin pulp, Ready to eat



System for issuing electronic phytosanitary certificates in Sri Lanka

M.P.M. Senarathne, G.M.S.T. Gajanayake and W.A.R.T. Wickramaarachchi

National Plant Quarantine Service, Katunayake, Sri Lanka

AbstractElectronic phytosanitary certificate (ePhyto) is the electronic version of a

phytosanitary certificate, which is exchanged electronically between National Plant Protection Organizations of exporting countries and importing countries. ePhyto speeds up information exchange, reduces the cost and minimize the opportunities for fraud and loss of certifications during the exchange and thereby facilitates to plant and plant product trade across the globe. Sri Lanka has been selected by the International Plant Protection Convention (IPPC) as a pilot country to implement the ePhyto project since Sri Lanka has a huge potential for the ePhyto implementation due to its strategic location based on knowledge of process and enthusiasm of exporters, importers and National Plant Protection Organization (NPPO) officers where outcome of the global survey conducted by IPPC in 2015. At present, some developed countries electronically exchange ephyto through point to point exchange method by using their own national systems. However, Sri Lanka does not have an own national system. Thus Generic ePhyto National System (GeNS) has been introduced by the United Nations Computing Centre (UNICC) to countries which do not have their own national systems to create ePhyto. NPQS has implemented pilot GeNS project in collaboration with IPPC, UNICC and Australian Department of Agriculture and Water Resources (DAWR). GeNS is a web based system and it facilitates generating and sending ePhyto. ePhyto implementation project in Sri Lanka was started in 2016. IT infrastructure development of seventeen workstations was completed in 2017 with the support from the Ministry of Telecommunication and Digital Infrastructure, Sri Lanka. Industry awareness sessions on implementation of GeNS were conducted by ePhyto Steering Group of IPPC in December 2016. Qualified staff with sound knowledge of English and ICT in addition to plant quarantine aspects is the key strength of Sri Lanka. Since November 2018, GeNS is under User Acceptance Testing (UAT) in Sri Lanka. UAT of GeNS are being conducted with NPPO officials and with selective representatives from the industry by Sri Lankan ePhyto team. GeNS has also been modifying based on feedback of them. Since Electronic Phytosanitary certificate system is more beneficial for all the stakeholders, this system has been implemented under testing level in Sri Lanka. ePhyto will be shared under production environment in near future.

Key Words: Electronic certificate, National System, Phytosanitary certificate, Plant quarantine, GeNS, Workstations



Impact of Permanent Crop Clinic Programme (PCCP) for the management of pest and diseases in Galle district

S.H. Kahingala

Provincial Department of Agriculture, Southern Province, Sri Lanka

AbstractAgriculture is one of the most important sectors in Sri Lankan economy. It is

an important source of employment for the Sri Lankan workforce. Crop cultivation is the main economic activity of the people living in rural areas and need to improve crop cultivation and its productivity. There are more advantages and needs in improving crop production. The provision of accurate and effective pest control measures to the farmers is the responsibility of the Department of Agriculture in Sri Lanka. This study was conducted to evaluate the permanent crop clinic programs in Galle district. This was conducted by Galle - western zonal area and covered the 23 plant doctors including 16 permanent plant crop clinics. The sample consisted of 60 farmers those who comes to the plant crop clinics during the Maha 2016/17 season. The primary data collection methods were interviews, questionnaire surveys and key informant discussions. Personal individual interviews were done by investigator using the prepared questionnaire. The results were analyzed using SPSS software. Nearly 45% of the farmers visited to plant crop clinics at least two times during Maha 2016/17 season. 77% of farmers visited to crop clinics to identify unknown pest and diseases in respect to their cropping fields. Majority of the farmers are highly satisfied of the advices given by plant doctors (56%). Majority of the farmers (36%) preferred to visit plant crop clinics conducted on Saturdays. Meantime 22% of farmers willing to visit plant crop clinics on Wednesdays because due to availability of plant doctors. When considring the farmers’ preference time to visit crop clinic is around 85% of the farmers were preferred to visit clinic in the evening and 15% willing to visit in the morning. 88% of farmers have strongly positive attitudes towards the tools using when diagnose. Only 12% of farmers have the moderate attitudes towards the tools using when diagnosing. Around 35% of farmers get prescription sheets which are easy to understand. None of the farmers got prescription sheets that were very difficult to understand. From plant crop clinics 53% of farmers got the prescription instructions with highly practicle solutions and only 7% of farmers mentioned the given instructions were not practical. Need to address household farming sector with the plant crop clinic and co-ordination among the private agrochemical dealers and government plant doctors are needed. It will reduce the wrong prescriptions, mishandling and over usage of agrochemicals in crop fields.

Key words: Maha season, Plant crop clinics, Prescription sheets.



Analysis on failure to comply with export phytosanitary requirements by Sri Lanka

G.G.D. Lalani and D.C.H. Kumarasinghe

National Plant Quarantine Service, Canada Friendship Road, Katunayake, Sri Lanka

AbstractThe National Plant Quarantine Service (NPQS) acts as the National Plant

Protection Organization (NPPO) for Sri Lanka to the International Plant Protection Convention (IPPC) which is an international plant health agreement that aims to protect cultivated and wild plants by preventing the introduction and spread of pests in regard of phytosanitary requirement fulfillment for international trade. According to ISPM 13 standard of IPPC, adopted by the third session of the interim commission on phytosanitary measures in April 2001 common reasons for receiving of Non Compliance (NC) with violation of phytosanitary requirements including failure to comply with phytosanitary import requirements, detection of regulated pests, failure to comply with documentary requirements, prohibited consignments, prohibited articles in consignments (e.g. soil), evidence of failure of specified treatments, repeated instances of prohibited articles in small, non-commercial quantities carried by passengers or sent by mail. Considering the past four years’ non-compliances; presence of harmful organism, document errors, prohibited items and absence of special requirements are the major reasons for receiving non-compliances by Sri Lanka. There is an increasing trend of receiving non-compliance in 2019 due to unauthorized exports without phytosanitary certificates, which is beyond the control of National Plant Quarantine Service. Further export through postal and courier services and carrying in accompanied baggage in small quantities without complying with the export conditions have led to the interception at the destinations and subsequent increase non-compliances against Sri Lanka. Number of corrective measures have been taken by the National Plant Quarantine Service to reduce the number of non-compliance notifications. Raising awareness, strengthening field certification and auditing, bringing many crops under certification program, banning of farmer fields inability to comply with the phytosanitary conditions are the key measures taken to rectify this issue. Complying with phytosanitary conditions is most important to Sri Lanka to secure in international trade and it is all our responsibility as Sri Lankans to be in line with the required phytosanitary requirements for relevant countries.

Key words: International Standards for Phytosanitary Measures, National Plant Quarantine Service, Non-compliance, Phytosanitary Certificate, Phytosanitary requirement



Strategies for sustainable management of Fall Army Worm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) in Sri Lanka

K.N.C. Gunewardena, S.M.A.O. Nadeeshani and P.A.I. Sandaruwani

Field Crops Research and Development Institute, Mahailluppallama, Sri Lanka

AbstractFall Army Worm (FAW) Spodoptera frugiperda (Lepidoptera: Noctuidae) is

a destructive pest of maize and several other food crops. It is native to tropical and sub-tropical regions of America and has been reported for the first time in India in July 2018 and in Sri Lanka in October 2018. As the first line of defense, the Department of Agriculture identified a few safer and effective insecticides for the management of FAW. In order to develop sustainable management strategies for FAW, the Field Crops Research and Development Institute initiated several experiments during Maha 2018/19. Experiments conducted included field evaluation of 16 varieties including 14 hybrids for resistance to FAW, field evaluation of female sex pheromones as a monitoring device and testing of candidate insecticides and seed treatments for FAW control. Of the sixteen varieties evaluated, PAC 984, MI MZ HY 02, Jet 999 and Rambo performed better than the other hybrids in terms of FAW damage. Severity of cob damage was low in all the tested hybrids. Of the two female sex pheromone lures tested, lure from UK (Russel IPM) attracted more male moths than to the female sex pheromone lure from Greece (SpoFru). Of the Thirteen insecticides tested in farmers’ fields, five (Spinotoram 25% WG, Spinosad 2.5 SC Emamectin benzoate 5% SG, Chlorantraniliprole 20 SC and Chlorantraniliprole 20% + Thiamethoxam 20 % WG) were identified as effective against FAW. None of the seed treatments (Thiamethoxam 70% WS and Imidacloprid 70% WS) tested were not effective in controlling FAW at seedling stage.

Key words: Fall Army Worm, Insecticides, Maize, Seed treatments, Spodoptera frugiperda



Introduction of the potential to develop pumpkin (Cucurbita maxima) based food products

H.M.N.D.B. Hennayake1, S.M.A.C.U. Senarathne1, N.W.K.U. Niranjala2, N. Liyanage2, K.W.P.D. Karandawala1 and D.K. Wijerathne1

1Food Research Unit, Department of Agriculture, Gannoruwa, Sri Lanka 2University of Ruhuna, Mapalana, Kamburupitiya, Sri Lanka

AbstractPumpkin is one of the food items recommended by dieticians for controlling

cholesterol and reducing weights. Although the surplus production is available in the market, the demand for the product is low. A study was conducted to develop pumpkin based food products to face the said problem, to increase palatability of pumpkin and to improve vegetable consumption among Sri Lankans. Two pumpkin drinks; smoothie and ready to serve drink (RTS) and puree were produced. Pumpkin smoothie was prepared by adding two milk types; Soy milk and cow milk and yoghurt to the pumpkin pulp. Ready to serve drink of pumpkin was prepared by pumpkin pulp, water, sugar and citric acid in different combinations. Pumpkin puree was directly extracted pulp of the pumpkin. The organoleptic properties of the smoothie and drink including color, taste, odor, texture and overall acceptability were assessed by 15 member semi trained panelists, through five point hedonic scale and analyzed using Kruscal-Wallis One-Way ANOVA Test. Parameters of physiochemical properties such as TSS, °Brix, pH, % Acidity and microbiological examination of bacterial counts, yeast and mold were measured for storage period of 2 months. RTS, Smoothie and puree showed 8%, 11% and 4% total soluble solids, acidity of all products were <0.1% and pH were 4.1, 5.6 and 4.05 respectively showed SLS recommended results with significant sensory attributes. Microbiological analysis was also revealed that products were safe for consumption for two months period of storage life. The production cost of 1 l of pumpkin smoothie, ready to serve drink and puree did not exceed Rs. 100.00, 50.00 and 80.00 respectively even at the end of the season. Therefore, pumpkin smoothie, ready to serve drink and puree have great potential to be popularized among the health concerned consumers.

Key Words: Food products, Organoleptic properties, Pumpkin



Effect of admission qualification on the performance of students of the diploma in agriculture and demand for

public sector employment

A.K. Jayawardena

Extension and Training Centre, Peradeniya, Sri Lanka

AbstractCourse of diploma in Agriculture producers middle level technical officers for

both local and foreign labour markets. The diploma in Agriculture has been upgraded to Higher National Diploma in Agricultural Production Technology (NVQ - 06). Similarly, students intake has been increased by broadening the opportunity to apply for the course by giving a chance to students who follow newly introduced subject stream of technology in Advanced Level. The objectives of the study were to determine the effect of the admission qualification on the performance of students of diploma and to assess their potential in meeting the demand for middle level technical officers in public sector. Number of subjects passed in Advanced Level examination does not show considerable effect on the passing out rate of diploma holders. However, it had a relationship with the class obtained by the diploma holders. Thus, the number of drop outs and repeaters are governed by the pattern of passing out diploma holders and there is no positive relationship between number of intake and rate of passing out. Most of the drop outs comes under student group having 03 passes in Advanced Level examination because, they are the most capable and willing group for higher education and ensured jobs. Major reason that affect for the shortage of diploma holders in Agriculture in public sector was the recruitment of only the diploma holders who have 03 passes in advanced level examination to the post of Agriculture Instructor in public sector in terms of the existing recruitment procedure. Therefore, 26% out of the 60% of diploma holders who pass out from the School of Agriculture are only able to be recruited as Agriculture Instructor of the public service. It can be concluded that the shortage of diploma holders in public sector cannot overcome only through the increment of student intake to the School of Agriculture.

Key words: Admission Qualification, Demand, Middle level technical officers, Performance of Diploma students, Public sector



Introducing nutrition labeling for a better choice of Helabojun food

D.S. Rathnasinghe1, S. Gunathilaka2 and U.H.M. Subuddhika3

1Agro-enterprise Development and Information Service, Peradeniya, Sri Lanka2Womens’ Agriculture Extension Unit, Peradeniya, Sri Lanka

3Young Farmers’ Club Head Quarters, Peradeniya, Sri Lanka

AbstractHelabojun (HB) is the local food promotion initiative of the Department of

Agriculture, while providing entrepreneurship opportunities for low income women. With the introduction of many attractive features, HB food outlets are becoming very popular. The foods served at HB are prepared only from local raw material, of which majority are cereal and pulse based preparations. There are claims about high starch and oil contents and the healthiness of the available traditional food at HB. With the DOA intension of using HB outlets as places to give nutritional messages to public the message of nutrient based intake is expected to transfer to its consumers through nutrition labeling. Hence HB food compositions were analyzed by inputting data of ingredients and measurements of recipes into a nutrition data base. Energy, Total fat, Protein, Calcium, Iron, Folate, Vitamin A and Vitamin C were found and the percentages of values in a single serving were calculated in terms of the daily recommendation.The food served at HB was categorized as breakfast substitutes, snacks, sweets, beverages, and desserts to become the results meaningful. Out of the breakfast meals, the highest calories are provided by red and white rice string hoppers (180 g) with green gram curry (100 ml) and sambol (60 g). The percentage of calorie supply is 46.1% of the daily calorie requirement which is considered as 2100. Recently introduced vegetable plate and balanced roti were recently introduced but they were not very demanding. Vegetable salads are among the lowest calorie providers. Out of the sweets, rice flour pan cake, followed by rice flour dodol provides the highest calories, i.e. 376 (17.9%) and 362 calories (17.2%) respectively. Herbal porridge with 20 g jaggery provides the highest calories i.e. 232 (11%) of all available beverages. Out of the available snacks Unduwade (blackgram wade) provides the highest amount of calories, (401 calories) i.e. about one fifth of daily calorie requirement (19%) by consuming one item. Similarly Protein, Fat, Calcium, Vitamin A supplies by HB food were measured. Nutrition labels describe the nutrient contents of available food and the percentage of daily dietary requirement provided by one serving. This will educate the consumers about nutrient content of food, increase awareness on reasonable serving sizes and will motivate consumers to make healthy choices.

Key words: Nutrition labelling, Healthiness, Serving size, Nutrition data base, Calorie requirement



Farmer empowerment in Damana Agrarian Service Center of Ampara inter provincial area through small farmer production

society approach

J.R. Sudasinghe1, U.C.S. Perera2, M.F.A. Zaneer2, A.B.M. Wijatatunga1 and P.N.M. Dayarathna2

1Extension and Training Centre, Peradeniya, Sri Lanka

2Deputy Director of Agriculture Office (IP), Ampara, Sri Lanka

AbstractFormal farmer organizations registered under Irrigation Management Division

of the Department of Agriculture mainly focuse on Water management in the major irrigation area. Existing issues in farming practices in Agricultural production are not being properly addressed through such farmer organizations. In order to bridge the gap, Department of Agriculture introduces an extension approach known as small farmer societies which have been implemented since early 1990s in the Interprovincial Areas. However, this approach was not sustainable due to a number of reasons such as inappropriate planning, lack of monitoring and evaluation. Phalalanda Agriculture Instructors Range under Damana Agrarian Services Centre Division in Ampara Interprovincial Area has shown significant performance towards the farmer empowerment by successful implementation of four small farmer production societies. Cultivation plan and burning technical issues are discussed in regular monthly meetings. Scheduled cultivation programmes formulated specially for each society are being discussed for their better implementation at the regular monthly meetings while addressing all technical issues faced by the farmers. Further, specific field issues are instantly attended by the extension worker. Implementation of seasonal extension targets assigned to relevant extension worker through these production societies is an added advantage. Adoption of appropriate Agricultural technologies and their sustainability are assured due to mutual bond and recognition among members and extension officers. Revolving fund totaled up to LKR 6 million of the societies are an excellent means making affordable credit available to the members for input supply and their welfare activities. Three societies have used these revolving funds to acquire agro-machinery like combine harvesters which are being utilized as a model of custom hiring. Farmer empowerment with increased yield, additional income sources, small scale financial investments and better welfare have been achieved through this small farmer production society approach.

Key words: Agriculture Extension, Small farmer production society, Farmer empowerment



Evaluation of moss gel as a low cost solidifying agent to substitute agar in plant tissue culture

S.M. Nagahawaththa1, L.I.A. Amarawansha2, D.L.D. Lakmali1, L.G.G. Indika1 and P.A. Weerasinghe2

1Tissue Culture Division, Plant Virus Indexing Center, Gabadawaththa, Homagama, Sri Lanka

2Department of Plant Sciences, Faculty of Agriculture, Rajarata University of Sri Lanka, Anuradhapura

AbstractHigh cost of production is one of the major constraints in Plant Tissue

Culture which is mainly due to high chemical cost. Agar is the most commonly used solidifying agent (LKR 8000/kg:Brand-Meron-India) which costs 60-70% of the total media production cost. Mossgel is one of the low cost solidifying agents (substitute for Gelatine) that can be found in the local market (LKR 3800/kg). Moss gel is extracted from sea weeds like Chondruscrispus, Gracilaria. This study was conducted to identify the suitability of moss gel as a low cost substitute for Agar in shoot induction and multiplication of Banana, shoot multiplication and rooting of Orchids and Anthurium. Suitability and best concentration of the moss gel were assessed using survival percentage, multiplication rate and number of shoots and roots per culture. Moss gel concentrations of 6.5 gl-1, 7 gl-1, and 7.5 gl-1 were selected as treatments and those were compared with the control (Agar 7 gl-1). In Banana initiation, highest shoot survival percentage (94.4%) was recorded in 6.5 gl-1 moss gel treatment and the lowest (55.5%) was in the control treatment. There were no significant differences among four treatments (p>0.05) for multiplication rate, number of shoots per culture in Banana and number of roots per culture in Orchid and Anthurium. Therefore, the lowest moss gel concentration(6.5gl-1) can be used for initiation and multiplication of Banana, multiplication and rooting of Orchids and Anthurium. However, highest multiplication in Banana and Anthurium was observed in moss gel 7 gl-1 concentration while moss gel 7.5 g/l is best for rooting of Anthurium. In conclusion, agar can be replaced with moss gel effectively and the cost of tissue culture media can be reduced by 50%.

Key words: Low cost tissue culture, Moss gel, Solidifying agent



Blyxa octandra (Family: Hydrocharitaceae): A newly emerging aquatic weed in rice fields of Wet zone and Intermediate zone

in Sri Lanka

R.M.U.S. Bandara1, R.M.N.H. Senanayake1, T.K. Illangakoon1, S.R. Sarathchandra1, W.M.U.B. Wickrama1, Y.M.S.H.I.U. de Silva1, H.M.M.K.K.H. Dissanayaka1,

D.G.K.P. Wijerathne1, H.M.G.M.K. Weerasooriya2, U.G.S.P. Gunasekara2, E.M.P. Ekanayake2 and R.A.S.W. Ranasinghe3

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka2Provincial Department of Agriculture, Central Province, Sri Lanka3National Herbarium, Department of Botanical Garden, Sri Lanka

AbstractBlyxa octandra is an aquatic herb characterized by elongate leaves with a length

of 10-16 cm and a width of 0.5-1 cm. During Maha 2018/19 season this weed plant was reported in the rice fields of Batalagoda and rice fields of Giragama area. A farmers’ field experiment was carried out to find out herbicides which effective on this weed. It was found out that application of post-emergent one-shot herbicides; Bispyribac sodium 100 g/l at the rate of 300 ml/ha within 8-14 Days After Establishment (DAE) and Pretilachlor 300 g/l + Pyribenzoxim 20 g/l EC at the rate of 1.25 l/ha within 06-10 DAE were effective in controlling this weed. Blyxa octandra weed controlling efficacy of Bispyribac sodium 100 g/l and Pretilachlor 300 g/l + Pyribenzoxim 20 g/l EC were 94% and 91% respectively.

Key Words: Aquatic herb, Blyxa octandra, Rice, Herbicides


** Research News

New threaten pest to Annona muricata L.

K.A.J.C. Premawardhane, H.K.Kumuduni, W.A.C.K. Wickramasinghe and W.M.C.N. Wijesinghe

Regional Agriculture Research and Development Centre, Makandura, Gonawila,

Sri Lanka

AbstractAnnona cultivation in some areas in North Western province found to be

damaged by an unrecorded pest, bark eating caterpillar (Indarbela quadrinotata) (Lepidoptera: Metarbedelidae). The biology and ecology of this insect was studied by making regular larval samplings in the field and rearing them in the laboratory on true branches of Annona to identify the pest, 2015. It had a single generation per year in the host range of Annona, Guava, Pomegranate and Nelli in the observational period in Sri Lanka and it infested at highly bearing stage in trees causing young shoots dry and die away giving die-back symptoms. The infestation of the pest was clearly identified by small holes in the bark and irregular tunnels covered with silken web consisting of wooden particles and excreta on the bark of the main stems and branches. Eggs are laid in clusters on the bark of trees hatched after 8-10 days. Larvae with dark brown heads bore into the trunk or main branches and the larval period lasts for 7-9 months. The full grown larvae are 30-50 mm with sparse hairs and body has simple thoracic legs with the last segment ending in a curved claw. The pupa is light brownish, 1.5 cm in length and with 2 short pointed cephalic processes. Adult moths are 35-40 mm, pale brown or grey wavy markings on the wings and measures 15-18 mm across the wings. Forewing has a sub-apical brown spot and with several transverse rows of brown scales. Hind wing is light black in color. Antennae have strong and uniform pectination. The larval period was from July to March, pupal period in February - March and moth emergence during April to May. Maintaining the good sanitation, observe the field periodically for die-back symptoms, pruning the infested parts, removing the larvae mechanically by inserting a hooked metallic probe, removing the webs and sealing it with mud kills the larvae effectively.

Key words: Indarbela quadrinotata, Annona cultivation, New pest


** Research News

Pre-plant, total killer herbicide, Tiafenacil 50 g/l ME: as an alternative for Glyphosate and Paraquat

R.M.U.S. Bandara1, D.M.J.B. Senanayake1, W.M.U.K. Rathnayake1, U.A.K.S. Udawela1, J.A. Sumith4, H.A.S.N. Hettiarachchi2, L.C. Silva3,

U.S.K. Abeysinghe4, W.M.U.B. Wickrama1, Y.M.S.H.I.U. de Silva1, H.M.M.K.K.H. Dissanayaka1, M.R.A.B. Madduma1, I.B.J. Bandara3, S. Sivanason5,

P.R.T.E.W.M.R.B. Ekanayake6 and J.D.H.E. Jayasinghe6

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka2Agriculture Research Station, Seetha Eliya, Sri Lanka

3Field Crop Research and Development Institute, Mahailuppallama, Sri Lanka4Office of the Registrar of Pesticides,Getambe, Peradeniya, Sri Lanka

5Rice Research Station, Paranthan, Sri Lanka6Lankem Ceylon PLC, Sri Sangaraja Mawatha, Colombo, Sri Lanka

AbstractGlyphosate and Paraquat like total weed killers have been banned in Sri Lanka

in the past. Since then, most of the agricultural sectors; specially paddy, tea and other field crop cultivations had to find solutions to control weeds. However, most of the methods used currently are highly labor required, high time consuming and highly expensive. Therefore, to address the issue a total weed killer is highly required at the moment. Tiafenacil 50 g/l ME is a newly developed herbicide molecule by Farm Hannong, South Korea. It is a non-selective, post emergent, contact herbicide which is effective in low concentration and showing a speedy action, short soil residual activity, wide spectrum and adjuvant built in. It is a protoporphyrinogen oxidase enzyme inhibitor. Protoporphyrinogen oxidase (PPO) is an enzyme in the chloroplast cell that oxidizes protoporphyrinogen IX (PPGIX) to produce protoporphyrin IX (PPIX). PPIX is a precursor molecule for both Chlorophyll and Heme. A multi-locational field experiment was conducted adopting RCB Design with 03 replicates during the month of July 2018 at four different locations namely Manapaha, Mukalanyaya, Mahailluppallama and Seetha Eliya in order to evaluate bio efficacy of Pre-plant herbicide; Tiafenacil 50 g/l ME in paddy and non-crop land and to find out the most suitable dosage to be used in Sri Lanka in paddy and non crop lands. Tiafenacil 5% ME is a broad spectrum, non-selective weed killer with newly invented mode of action. This study was conducted to evaluate bio efficacy of Tiafenacil 50 g/l ME in paddy and non-crop land and to find out the most suitable dosage to be used in Sri Lanka in paddy and non-crop lands. Tiafenacil 5% ME formulation at the rate of 3750-5000 ml/ ha could be recommended to control weeds in highlands whereas Tiafenacil 5% ME formulation at the rate of 2500 - 3125 ml/ ha could recommended to control weeds in lowlands. As this is a contact type herbicide wetting of entire foliage is a must to have a good efficacy.

Key words: Noncrop land, Pre-palnt herbicide, Rice, Tiafenacil, Total killer


** Research News

Phytotoxicity of Herbicide, Florpyrauxifen benzyl 25 g/l EC to cultivated rice

R.M.U.S. Bandara1, B. Marambe2, D.M.J.B. Senanayake1, W.M.U.K. Rathnayake1, U.A.K.S. Udawela1, W.M.U.B. Wickrama1, Y.M.S.H.I.U. de Silva1,

H.M.M.K.K.H. Dissanayaka1, D.G.K.P. Wijerathne1, M.A.R.B. Madduma1, R.P. Upali3, K.A.K. Premarathna3, U.B.U. Attanayaka3 and U.S.K. Abeysinghe4

1Rice Research and Development Institute, Batalagoda, Ibbagamuwa, Sri Lanka2Department of Crop Science, Faculty of Agriculture,University of Peradeniya,

Sri Lanka3Office of the Deputy Director of Agriculture, Polonnaruwa Inter Province,

Department of Agriculture, Sri Lanka4Office of the Registrar of Pesticides, Getambe, Peradeniya, Sri Lanka

AbstractFlorpyrauxifen benzyl 25 g/l EC is a one shot post-emergent herbicide recently

recommended in rice cultivation in Sri Lanka. It is a synthetic auxin. It has been recommended to apply at the rate of 1500 ml/ha within 7-12 days after establishment. Farmers of Polonnaruwa, Anuradhapura, Ampara, Moneragala and Hambantota had applied this herbicide during Maha 2018/19 and experience herbicide injuries in their crops. Growth of the main tiller of the rice plant ends up with a leaf like onion leaf, plant getting twisted in some of paddy fields. Mainly in farmers fields Bg 360, Bw 367, Bg 379-2 had experienced a severe herbicide injuries compared to other rice varieties. Therefore, a set of field experiments were conducted to study the phyto-toxicity of herbicide Florpyrauxifen benzyl 25 g/l EC on rice. Four rice varieties namely Bg 300, Bg 360, Bw 367 and Bg 379-2 were used as check varieties. Four herbicide treatments namely 2250 ml/ha, 1875 ml/ha, 1500 ml/ha (DOA recommendation) and 1125 ml/ha were tested for above rice varieties. Percentage herbicide injury severity was recorded at 15 days after herbicide application according to the Standard Evaluation System for Rice (IRRI, 2014). Per plant yield was recorded. Meanwhile 20 rice varieties bred at RRDI, Batalagoda were screened for their herbicide injury severity. Bw 367, Bg 359, Bg 360, Bg 366, Bg 374, Bg 379-2, Bg 403 and Bg 406, Bg 358 and Bg 94-1 are found to be more sensitive varieties to phyto-toxicity of Florpyrauxifen benzyl 25 g/l EC. The rate of herbicide, Florpyrauxifen benzyl 25 g/l EC has to be revised in a manner that there is no toxicity to rice crop while the dosage of herbicide effective on weed control through a research study. If we proceed with current recommended dosage, there is a risk of herbicide injuries for sensitive varieties.

Key words: Herbicide injuries, One-shot herbicide, Phyto-toxicity, Post-emergent, Sensitive varieties


** Research News

Adaptability of a newly released Horana Hybrid - 01 papaw under Low Country Dry zone condition

S.J. Arasakesary, S. Rajeshkanna, S. Mugunthini and A. Amirthalojanan

Regional Agriculture Research and Development Centre, Iranaimadu Junction, Kilinochchi, Sri Lanka

AbstractPapaw is a popular fruit which is famous for its high nutritive and medicinal

value, and it is cultivated primarily in home gardens. However, there is limited extent under commercial scale and this extent is steadily increasing. It is primarily being cultivated in 5,913 ha with total production of 74,492 mt/year (Agstat,2017). Ratna, Known Your Number One, Sun rise, Solo Hawai and Red lady are the common F1 hybrids and varieties cultivating in Sri Lanka. A recently released Horana Hybrid-1 papaw was cultivated in Regional Agriculture Research and Development Center Kilinochchi during September 2016 to 2018 August (2 years) in order to test the crop adaptability in Low Country Dry zone. 150 plants were planted with the spacing of 2.5 x 2.5 m. Basin irrigation was applied. Basal, Top and other split fertilizers and crop protection measures were adopted as per the Department of Agriculture recommendations. Growth and yield parameters were recorded and averaged values were compared with standard value of Horana hybrid-1 (VRC, 2014).

First flowering was observed at the average Plant height of 146 cm and 50% flowering observed at 120 days after planting. 2.32 mt/ha plot yield was received with 120 fruits per plant (standard-90) and average fruit weight of 1.45 kg (standard 1.2-2.6 kg) in life span of the plant. One Plant also produced 174 kg (standard 120 kg/plant) fruits from a life cycle. Already adopted Imported red lady variety is extra dwarf, early bearing and vigorous and productive. Plants begin to bear at 60-80 cm height and could yield over 30 fruits per plant in each - fruit bearing season. Fruits are short - oblong on female plants and rather long shaped on bi-sexual plants, weighing about 1.5-2 kg. Therefore these results revealed that Horana Hybrid -1 papaw also have high adaptability in Low Country Dry zone and it can be cultivated by Dry zone farmers to get better yields in papaw cultivation commercially.

Key words: Horana Hybrid - 01, Adaptability, Dry zone

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Ms A.S.K. Abeysekara No. 166, Seeradunna, Mawathagama.

Dr S. Abeysiriwardhana CIC Agribusiness, Pelwehera, Dambulla.

Dr L. Amarasinghe C 289/4, Dompitiya, Hingula.

Prof. D.P.S.T.G. Attanayaka Department of Biotechnology, Faculty of Agriculture and Plantation Management, Wayamba University.

Dr (Ms) W. Balasooriya Department of Biotechnology, Faculty of Agriculture and Plantation Management, Wayamba University.

Dr K.A.N.P. Bandara Horticulture crops Research and Development Institute, Gannoruwa.

Dr C. Benaragama Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr W. Chitral 100A, Ganhatha Road, Kirinda, Weligalla.

Prof. N.D.K. Dayawansa Department of Agric. Engineering, Faculty of Agriculture, University of Peradeniya.

Prof. (Ms) D. de Costa Department of Agric. Biology, Faculty of Agriculture, University of Peradeniya.

Mr R.S.Y. de Silva Gunamuni Niwasa, Godagama, Kosgoda.

Dr (Ms) U. Dissanayake Department of Agric Extension, Faculty of Agriculture, University of Peradeniya.

Dr D.M.N. Dissanayake No. 10, Keerthi Mawatha, Mahaweli Uyana, Watapuluwa, Kandy.

Prof. (Ms) J.P. Eeswara Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Mr S. Emitiyagoda No 284, Balagolla, Kengalla.

Dr (Ms) D.R.R.M. Fonseka Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr H. Fonseka 256F, Jasmine Garden, Arattenna, Peradeniya.

List of Reviewers

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Dr (Ms) D.R. Gimhani Department of Biotechnology, Faculty of Agriculture and Plantation Management, Wayamba University.

Prof. L.H.P. Gunarathne Department of Agric. Economics, Faculty of Agriculture, University of Peradeniya.

Dr S. Heenkenda 78, Warapitiya, Kundasale.

Dr K.S. Hemachandra Department of Agric. Biology, Faculty of Agriculture, University of Peradeniya.

Dr K. Hettiarachchi No 288, Sri Jayawardhanapura Mawatha, Rajagiriya.

Prof. H.M.G.S.B. Hitinayake Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr D.P.P. Jayakodi National Plant Quarantine Service, Canada Miththrathwa Mawatha, Katunayaka.

Prof. I.D.A.N. Jayakody 481 - 1E, Homagama Road, Athurugiriya.

Prof. S.J.B.A. Jayasekara No 482/B, Suhada Mawatha, Millennium Drive, Chandrika Kumaranathunga Mawatha, Malambe.

Dr L.N.A.C Jayawardena Department of Agric. Extension, Faculty of Agriculture, University of Peradeniya.

Dr T.A. Jayaweera Department of Zoology, Faculty of Science, University of Peradeniya.

Mr K.E. Karunathilaka 42/A, Tissarama Mawatha, Dangolla, Kandy.

Mr K.M.A. Kendaragama No 155/1, Sirikulam Watta, Mallawapiriya, Kurunegala.

Dr (Ms) K.W. Ketipearachchi Natural Resources Management Centre, Peradeniya.

Prof. T. Madhujith Department of Food Science, Faculty of Agriculture, University of Peradeniya.

Prof. L. Manawadu Department of Geography, Faculty of Arts, University of Colombo.

Prof. B. Marambe Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

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Dr (Ms) B.E.P. Mendis Department of Food Science, Faculty of Agriculture, University of Peradeniya.

Dr K.A. Mettananda 303C1, Dengamuwa watta, Madarariyagoda, Kadugannawa.

Dr (Ms) J. Mohotti Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Prof. U.K.J. Mudalige Department of Agribusiness Management, Faculty of Plantation Management, Wayamba University.

Dr M.S. Nijamudeen Filed Crops Research and Development Institute, Mahailluppallama.

Prof. S.P. Nissanka Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr L. Nugaliyadda No. 1/75, Batuambe Road, Nugawela, Kandy.

Dr (Ms) M. Nugaliyadda No 81, Sinhapitiya Waththa, Gampola.

Dr (Ms) C. Perera Department of Biology, Faculty of Agriculture, University of Peradeniya.

Dr (Ms) P.I.P. Perera Department of Horticulture and Landscape Gardening, Faculty of Agriculture and Plantation Management, Wayamba University.

Dr S. Premalal No 23/1, 1/1, Polhengoda Road, Narahenpita.

Prof. D.K.N.G. Pushpakumara Faculty of Agriculture, University of Peradeniya.

Dr R.G.A.S. Rajapaksha Horticultural Crops Research and Development Institute, Gannoruwa.

Dr R.P.N.P. Rajapaksha Department of Food Science, Faculty of Agriculture, University of Peradeniya.

Dr B. Ranaweera Department of Horticulture and Landscape Gardening, Faculty of Agriculture and Plantation Management, Wayamba University.

Prof. Ranjith Premalal Department of Agriculture Engineering, Faculty of Agriculture, University of Peradeniya.

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Ms Rose Rupasinghe No 274, Shrimath Kuda Rathwatha Mawatha, Dodamwala.

Dr G. Samarasinghe Horticultural crops Research and Development Institute, Gannoruwa.

Dr (Ms) P.W.S.M. Samarasinghe Thapathiyawa, Oththampitiya, Nelumdeniya.

Dr K.H. Sarananda No. 36, Wijethunga Mawatha, Pilimathalawa.

Dr (Ms) R.D.P.D. Senanayake Tea Research Institute, Thalawakele.

Dr D.M. Senavirathna Central Research Station, Department of Export Agriculture, Matale.

Dr D.N. Sirisena 4th Stage, Uyandana State, Kurunegala.

Prof. T. Sivananthawerl Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Prof. C. Sivayoganathan No 41, Initium Road, Dehiwala.

Prof. B.M.L.D.B. Sooriyagoda Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr H.M.P.A. Subhasinghe Intercropping & Betel Research Station, Narammala.

Prof. V.A. Sumanasinghe Department of Biology, Faculty of Agriculture, University of Peradeniya.

Prof. R.O. Thattil Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr (Ms) V.R.M. Vidhanarachchi Bandirippuwa Estate, Lunuwila.

Prof. W.A.D.P. Wanigasundera Wattaranthenna Passage, Kandy.

Prof. (Ms) J. Weerahewa Department of Agriculture Economics, Faculty of Agriculture, University of Peradeniya.

Prof. W.A.P. Weerakkody Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

Dr S. Weerasena 77B, Fair Lane, Peradeniya.

Dr K.W.L.K. Weerasinghe Department of Crop Science, Faculty of Agriculture, University of Peradeniya.

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Dr P. Weerasinghe 100/12, Weerakoon Walaw Waththa, Alawella Road, Hiththatiya, Matara.

Dr W.M.A.D.B. Wickramasinghe Wijayasiri Mawatha, Dadahogama, Kulugammana.

Dr R.R.A. Wijekoon Agriculture Modenization Project, Ministry of Agriculture, Rajagiriya.

Dr P.M. Wijerathna Devi Road, Mawilmada, Kandy.

Dr D.B.T. Wijerathna 202, Bauddhaloka Mawatha, Colombo.

Dr A. Wijesekara 47/1, Wewa Ihala road, Jaburaliya, Madapatha.

Prof. (Ms) K.M.S. Wimalasiri Department of Food Science, Faculty of Agriculture, University of Peradeniya.

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Instructions to authors

1. Annual Symposium of the Department of Agriculture will consider research papers, short communications, and abstract of posters authored by the officers of the Department of Agriculture for publications. In addition to the findings from the regular departmental work, collaborative work with institutions outside the department and postgraduate research relevant to Sri Lanka will also be considered.

2. Manuscripts should be written in English. They will first be evaluated by an internal committee and followed by a double blind review. The Annals of Sri Lanka Department of Agriculture will collaborate with the Tropical Agriculturist (TA) in publishing full paper. Papers with highly technically sound and scientific in nature will be selected as a full paper in TA. The abstract of full paper published in Tropical Agriculturist, Short Communications, abstract of the poster presentation of the symposium, will be published in the Annals of the Sri Lanka Department of Agriculture. In any case, the decision of the Editorial will be final.

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Journal articlesJoachim, A., W.R.S. Kandiah and D.G. Pandithesekera. 1933. Studies on paddy

cultivation 2. The effect of manures on the composition of paddy and soil. Tropical Agriculturist 81: 11-35.

Books (identical author and editor)De Datta, S.K. 1981. Principles and practices of rice production. John Wiley and

Sons, New York.

Books (edited by someone other than the author of article)Ladd, J.N. 1985. Soil enzymes. In Soil Organic Matter and Biological Activity,

Eds. D. Vaughan and R.E. Malcolm. pp. 176-221. Martinus Nijhoff Publishers, Dordrecht. The Netherlands.

ThesisPieper, R.D. 1963. Production and chemical composition of arctic tundra

vegetation and their relation to the lemming cycle. Unpublished Ph.D. Thesis. University of Peradeniya, Peradeniya, Sri Lanka.

Online Lachke, A. 2002. Biofuel from D-xylose the Second Most Abundant Sugar:

http://www.iisc.ernet.in/academy/resonance/pdf/p50-58.pdf (Accessed on 10.07.2014)

Research ReportsAnnals will also consider research reports for publication developmental activation of the extension division. Reports should include an abstract, an introduction, results,

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conclusion and references. Materials and methods and discussion could be included only if necessary. A report can be up to maximum of 8 printed pages.

Short Communications, Research News and PostersShort communications should not be more than five pages long and research news should be limited to one page. Abstracts of Posters shall not exceed 300 words.

ASDA SecretariatIn-service Training InstituteP.O. Box 21Peradeniya 20400

Telephone and Fax: 94-81-2385354E-mail: [email protected]

New varieties released by the Department of Agriculture - 2018


Pummello - Citrus maxima L.Variety - HRPummelo 1

Type of cultivar - Local cultivar (Clone)Origin - Selection from local cultivarsMethod of propagation - Vegetative propagation by grafting

Character Parameter

Yield 230 kg/Tree/YearFruiting season May-June (Major) and Oct-NovImportant traits

TreeSpines on tree AbsentFlower Solitary/InflorescenceInflorescence Axillary and terminalFlower type HermaphroditeFlower colour White

FruitShape SpheroidWeight 1,900 gFruit skin color YellowFruit surface texture RoughFruit attachment to stalk MediumFlesh colour Pinkish white (56 D)Number of segments 14Albedo colour WhiteJuice sac arrangement IrregularAlbedo thickness 1.5 cmBrix 9.1Acid 1.15


Annals of Sri Lanka Department of Agriculture 2019. 21 191

Pummello - Citrus maxima L.Variety - HRPummelo 2

Type of cultivar - Local cultivar (Clone )Origin - Selection from local cultivarsMethod of propagation - Vegetative propagation by grafting

Character ParameterYield 210 kg/Tree/YearFruiting season May-June (Major) and Oct-NovImportant traits

TreeSpines on tree AbsentFlower Solitary/InflorescenceInflorescence Axillary and terminalFlower type HermaphroditeFlower colour White

FruitShape Spheroid to EllipsoidWeight 1,325 gFruit skin color Greenish yellowFruit surface texture PapillateFruit attachment to stalk MediumFlesh colour Pink (23 C)Number of segments 10Segment shape uniformity UniformAlbedo colour PinkJuice sac arrangement UniformAlbedo thickness 2 cmBrix 8Acid 1.12



Wood Apple - Feronia limoniaVariety - ANKWoodApple 1


Character Parameter

Yield 800 - 1,000 kg/Tree/YearFruiting season June - AugustImportant traits

TreeSpines on tree Very lowFlower Solitary/InflorescenceInflorescence Axillary and terminalFlower type HermaphroditeFlower colour Light yellow

FruitShape SpheroidWeight 463 gDiameter 17.4 cmFruit skin color Dull WhiteFruit surface texture RoughShell Thickness 4 mmFruit attachment to stalk StrongPulp Colour Light BrownColour intensity UniformPulp Texture FibrousNo of Seeds 85 - 525



Wood Apple - Feronia limoniaVariety - ANKWoodApple 2


Character Parameter

Yield 800 - 1,000 kg/Tree/YearFruiting season June - AugustImportant traits

TreeSpines on tree Absent or rareDensity of branches DenseFlower Solitary/InflorescenceInflorescence Axillary and terminalFlower colour Light yellowFlower type Hermaphrodite

FruitShape OvalWeight 565 gDiameter 17.5 cmFruit skin color Dull WhiteFruit surface texture RoughShell Thickness 3.25 mmFruit attachment to stalk StrongPulp Colour Dark BrownColour intensity UniformPulp Texture FibrousNo of Seeds 60 - 508



Cluster Onion - Allium cepa L.Variety - ARLRO 2

Pedigree - Jafna local x Agrifound RoseOrigin - Locally developedMethod of propagation - Clones/Seeds

Character Parameter

YieldAverage no of bulbs per cluster 4.8Average bulblet weight 2.9 g

BulbPollar diameter 2.7 cm

Equatorial dimeter 3.0 cmTotal soluble solid content 14Flowering ability YesShape Broad ellipticSkin color Light pinkFlesh color Purple whiteNo of hearts 2 - 3

PlantOrientation ErectWaxiness Mediumpungency 13.5 - 14.5



Cluster Onion - Allium cepa L.Variety - ARLRO 3

Pedigree - ACA27 x ACA13Origin - Locally developedMethod of propagation - Clones/Seeds

Character Parameter

YieldAverage no. of bulbs per cluster 5.4Average bulblet weight 2.3 g

BulbPollar diameter 2.2 cm

Equatorial dimeter 2.2 cmTotal soluble solid content 16Flowering ability YesShape Index Value 1.15Shape OvateSkin color PinkFlesh color Purple whiteSkin thickness ThickNo of hearts 1 - 2

PlantColor Dark greenOrientation ErectPlant height 25 - 27 cmWaxiness Mediumpungency 15 - 18.3



Mung bean - Vigna radiata L.Variety - MIMB7

Pedigree - VC6371-94/VC6368(46-40-6)Type of cultivar - InbredLine designation - MIMB 14 - 254Origin - Locally DevelopedMethod of propagation - Seeds

Character Parameter

Growth habit ErectPlant height 50 - 65 cmStem color Light green

Leaf color GreenDays to 50% flowering 25 - 30 cmFlower color YellowSeed color GreenSeed surface SmoothSeeds per pod 10 - 12Seed shape RoundPod color BlackPod length 10 - 12 cmDays to mature 50 - 65 daysSeed soaking period 8 hrsCooking period 15 minutes

New technology released by the Department of Agriculture - 2019


Sprinkler irrigation based agronomic management package for chilli, big onion and mung bean

Technology z Mulching with paddy straw (5 t/ha), incorporation of organic manure (15 t/ha) and

manual application of inorganic fertilizer (Department of Agriculture recommended inorganic fertilizer)

z The similar agronomic management package with the addition of Albert’s Mixture (micro nutrient source)

Benefits z Crop productivity enhancement

- Onion 30 t/ha- Mung bean 2.5 - 3 t/ha- Chilli 45 t/ha

z The water saving compared to the surface irrigation systems is about 30 % in all three crops.



Drip irrigation based agronomic management package for chilli and big onion

Technology z Mulching with paddy straw (5 t/ha), incorporation of organic manure (15 t/ha) and

split application of fertilizer (Department of Agriculture recommended inorganic fertilizer) through fertigation.

Benefits z Crop productivity enhancement

- Chilli 45 t/ha- Onion 40 t/ha

z The water saving compared to the surface irrigation systems is about 70 % in chilli and 50 % in onion.



Desiccation and defoliation technique for machinery harvesting of Mung bean

Technology z To defoliate and dessicate, table salt should be applied when the first matured set

of pod become black colored and the second set of pods is starting to convert from yellow to black.

z Irrigation should not be practised 6-7 days before salf application.

z Apply salt at the rate of 35-40 g/l of water (0.5M Nacl)

z After 3 days of salt application, foliar dessication will occur and after 7 days of

application defoliation will take place.

Benefits z Facilitate machinery harvesting in mungbean to reduce the cost of cultivation



A feasible method to enhance storability and fruit quality of sweet orange

Technology z Shelf life of Sweet orange fruits can be extended in refrigerated conditions with

black polythene packing materials.

Benefits z Enhance fruit quality, shelf life and reduce post-harvest losses of Sweet orange.



Improved Alternate Wetting and Drying technique (Improved-AWD)

Technology

z 2 - 3 weeks after the crop establishment, irrigate the field up to 5 cm and allow to drain until water level goes down to 15 cm from the soil surface.

z Irrigate again up to 5 cm and allow to drain as above.

z Continue this process until first flowering.

z Continue irrigation to maintain 0 - 5 cm water level for two weeks from first flowering.

z After two weeks, stop irrigation and allow to drain out up to 15 cm from the soil surface.

z 2 weeks before expected date of harvesting, stop irrigation gradually.

Important z To measure the water level in the soil, use a PVC pipe/tube (diameter - 4”, length -

20 cm) making several holes on the wall.

z Insert the PVC tube into the soil up to 15 cm by removing mud inside.

z Number of tubes per area should be decided according to the landscape of the paddy tract (e.g. 3 tubes/ac, if the land is flat).

z Put a mark in the field where PVC tube is installed.

z Measure the water level using a ruler inside the tube.

z Pay attention to control weeds well at land preparation and before starting improved-AWD technology.

z Apply fertilizer when the soil is moist.

z Improved-AWD is a good practice for paddy fields having iron toxicity whereas it should not be applied for saline paddy fields.

Benefits z Save 10 - 20% of total water use in paddy cultivation in Dry and Intermediate zones

of major and minor irrigated areas.



Seedling treated with phosphorous fertilizer in parachute nursery P fertilization for seedling broadcasting method

Technology z Place 3 - 4 particles of phosphorous fertilizer (TSP) into the seedling hole of the

parachute tray before placing soil and paddy seeds.

z Broadcast TSP treated seedlings after 12 to 14 days.

Benefits z 25 kg TSP can be saved from one hectare, of paddy field.

z Reduced soil and water pollution.



Phosphorous fertilizer application in alternative seasons

Technology z Apply P fertilizer at the rates recommended by the Department of Agriculture only

in Yala season (at the rate of 55 kg/ha for irrigated paddy and 35 kg/ha for rainfed paddy)

z This can be practiced when soil P level is above 5 mg/kg. Check soil P levels using soil P maps before practicing this

Benefits z Saves 50% of the Phosphorous fertilizer (TSP) requirement in paddy cultivation

z Reduced soil and water pollution



Fumigation standards for liquid Phosphine for the control of quarantine pest of rice pineapple and bitter gourd

Technology z The following optimized standards are recommended as a quarantine treatment for

plant and plant products.

z 1,400 ppm Phosphine (100 g ECO2FUME/m3), 24 hour exposure period can be recommended as the most effective treatment standard for controlling melon fly infestation in Bitter gourd with minimum deterioration of fruit quality

z 300 ppm Phosphine (21.3 g ECO2FUME/m3), 7 hours exposure period can be recommended as the effective treatment standard for Mealy bug control in Pineapple with minimum deterioration of food quality

z 700 ppm Phosphine (50 g ECO2FUME/m3), 36 hours exposure period can be recommended as the effective treatment standard for in controlling all life stages of rice weevils

Benefits z Phosphine can be effectively used as a quarantine treatment for plant and plant

products to minimize the use of Methyl bromide to prevent risks involved in the use of metallic Phosphides.



Development of two types of jackfruit based vegetarian fingers enriched with mung been and okra

Technology z Incooperating three protein sources (Sprouted mung bean, Okra and Mushroom)

to jackfruit arils, two types of fingers were produced with different tastes and with different nutrient levels.

z One finger was made with sprouted mung bean and mushroom and the other with okra and mushroom.

Benefits z Utilization of Jackfruit through value addition



Preparation of Biochar as a soil amendment from rice husk and corn cob by slow pyrolysis process

Technology z “Kunthaniya” was modified and used to produce rice husk biochar.

z An inhale tube is introduced as modifications to the opening not to block the air supply into the chamber and the length of the chimney is adjusted with the introduced adjustable part which created sufficient draught of fresh air for continues and controlled combustion.

z Because of the same reason, pyrolyzing process is to be carried out consistently in modified Kunthaniya within the slow pyrolysis temperature range producing a homogenous product.

z “Double Barrel Technique” (DBT) is introduced to produce corn cob biochar (CC-BC) according to the particle size differences of the feedstock.

z In the DBT, two barrels with different sizes are used as the furnace and retort.

z Barrel used as the retort is smaller than the barrel used for the furnace and has a ring lock.

z Holes are made at the bottom of the exhaust to burn syn-gas produced during the pyrolysis process.

z Steps involved in the process are optimized and they are under slow pyrolysis condition to produce CC-BC.

Benefits z Farmer scale Pyrolyses and Pyrolysis methods to produce good quality rice husk

biochar (RH-BC) & corn cob biochar (CC-BC)



A soil P map to manage P fertilizer application in rice

Technology z Select the particular paddy field by opening the map in Google Earth Pro

Soil P maps of the Kurunegala, Polonnaruwa, Anurahapura and Puttalam districts

Average soil P map of Anuradhapura district in Google earth pro

z Click on the place and obtain soil P level and P fertilizer requirement as in Table.

Soil Test values and recommended TSP fertilizer levels for paddyAvailable P values (mg/ kg) TSP Recommend Basal fertilizer levels (kg/ ha)

Irrigated Paddy Rainfed Paddy< 5 55 35

5 – 10 30 20> 10 Nil Nil

Benefits z Reduce unwanted application of P fertilizer and save money that spend for P fertilizer,

otherwise minimize soil and water pollution in Anuradhapura, Polonnaruwa, Kurunegala and Puttalam distrcits

ASDA 2019 - Department of Agriculture Sri lanka

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