©CAB International 2013. Banana Systems in the Humid Highlands of Sub-Saharan Africa (eds G. Blomme, P. van Asten and B. Vanlauwe) 37

AbstractBanana is an important crop for food and income in Burundi. However, average annual yields are low (5 t/ha) because of low and declining soil fertility, and pest and disease pressure. To help overcome the challenges to banana production in the Great Lakes region of Central Africa, the Consortium for the Improvement of Agriculture-based Livelihoods in Central Africa (CIALCA) has been promoting and facil-itating access to new high-yielding, pest- and disease-resistant improved hybrid banana cultivars with good consumer acceptability. The agronomic performance of the improved hybrid ‘FHIA-17’ and six com-monly grown dessert banana cultivars was evaluated at six sites with contrasting altitudes across Burundi from 2008 to 2012. The data were analysed using linear mixed-effects modelling. ‘FHIA-17’ significantly outperformed the other cultivars as it had the heaviest bunch weight, was in the group of cultivars with the most hands and fruits, and the fruits were long and thick. The cultivars ‘ITC0680’, ‘Gros Michel’, ‘Prata’ and ‘Yangambi Km5’ had the next best agronomic performance, while the cultivars ‘Ikigurube’ and ‘Kamaramasenge’ had the poorest performance. The high agronomic performance of ‘FHIA-17’ shown in this research demonstrates how its increased cultivation may help to ensure the continued production of dessert types of bananas in Burundi and the food and income security of the population.

5 Agronomic Evaluation of Common and Improved Dessert Banana Cultivars

at Different Altitudes across Burundi

M. Kamira,1* R.J. Crichton,2 J.-P. Kanyaruguru,3 P.J.A. van Asten,4 G. Blomme,5 J. Lorenzen,4 E. Njukwe,6

I. Van den Bergh,2 E. Ouma6 and P. Muchunguzi4

1Bioversity International, Bukavu, Democratic Republic of Congo; 2Bioversity International, Montpellier, France; 3Bioversity International, Bujumbura,

Burundi; 4International Institute of Tropical Agriculture (IITA), Kampala, Uganda; 5Bioversity International, Kampala, Uganda; 6IITA, Bujumbura, Burundi

* E-mail: mkamira2@yahoo.fr

5.1 Introduction

The Great Lakes region in Central Africa is a major production area of bananas (Musa spp.), which has a higher per capita consumption than anywhere else in the world (Karamura et al., 1998). Burundi, located at the heart of

the Great Lakes region, is one of the poorest countries in the world, with more than half of the population living below the poverty line (UNDP, 2011). The majority of the population depends on agriculture for a living. With an annual production of close to 2 million t, banana is the main crop grown in Burundi,

38 M. Kamira et al.

before sweet potato and cassava (FAOSTAT, 2010). The crop occupies approximately 17% of the cultivated land area, represents 40% of the total agricultural production (CIALCA, 2007) and provides an important source of food and income. The banana fruit is eaten cooked as a vegetable or ripe as a fruit and is also used to produce beer and wine (Rishirumuhirwa, 2010).

The most common cultivars in the Great Lakes region belong to the East African high-land banana group (EAHB; AAA genome), and are mainly used for cooking and beer/wine production. EAHB plants grow well at altitudes of 1000–2000 m above sea level (masl) (Karamura et al., 1998). Other cooking types include the plantains (AAB) and ABB cooking bananas such as ‘Bluggoe’ and ‘Pisang Awak’. Both of these are more vigor-ous at lower elevations (0–600 masl for plantains and <1000 masl for ABB cooking types). The most common dessert cultivars in Burundi are ‘Kamaramasenge’ (AAB) and ‘Dwarf Cavendish’ (AAA) (Rishirumuhirwa, 2010), both of which can also be used for beer making. A number of newly introduced dessert banana cultivars are also grown, including ‘Gros Michel’ (AAA) and its dwarf mutant ‘Highgate’, and the ‘Giant Cavendish’ types (AAA) ‘Poyo’, ‘Lacatan’ and ‘Williams’. The Cavendish dessert bananas are generally found at lower altitudes (<800 masl), whilst Gros Michel types are found at a slightly higher altitude range (Karamura et al., 1998). ‘Prata’ (AAB, ‘Pome’) is another dessert cultivar, mainly grown at lower altitudes in the region, though in Burundi it still performs well in the highlands (De Langhe, 1986).

Average annual yields, however, are very low, at around 5 t/ha (FAOSTAT, 2010). Major production constraints include pests and diseases (Xanthomonas wilt, Fusarium wilt, bunchy top disease, black leaf streak, nematodes and weevils), low and declining soil fertility (Gold et al., 1994; INIBAP, 2003; CIALCA, 2007) and irregular weather pat-terns (CIALCA, 2008). These production con-straints are exacerbated by the fact that farmers have poor access to improved agro-nomic practices and production inputs, such as fertilizers, clean planting materials and improved cultivars with high yield and disease resistance traits.

To help overcome the challenges to banana production in Central Africa, the Con sortium for the Improvement of Agriculture-based Livelihoods in Central Africa (CIALCA) has been promoting and facilitating access to new high-yielding, pest- and disease- resistant improved hybrid banana cultivars that have good consumer acceptability (CIALCA, 2010). In this chapter, the results of a CIALCA-led agronomic evaluation in Burundi of the improved hybrid ‘FHIA-17’ (FHIA, 1993) and commonly grown dessert banana cultivars are reported. If ‘FHIA-17’ shows high agronomic performance, it is hoped that its wider dissemination to farmers and smallholders in the Great Lakes region could help to ensure food and income security in the face of present and future challenges to banana production.

5.2 Materials and Methods

Trials of the dessert banana hybrid ‘FHIA-17’ and the commonly grown cultivars ‘Gros Michel’, ‘Ikigurube’, ‘ITC0680’, ‘Kamara-masenge’, ‘Prata’ and ‘Yangambi Km5’ (Table 5.1) were carried out between January 2008 to March 2012 at six sites across Burundi (Table 5.2). The cultivars were planted from December 2007 to February 2008, with the exception of ‘FHIA-17’, which was planted in January–February 2010. Site latitude and longitude data were obtained by GPS (global position-ing system) (Table 5.2). The annual rainfall was derived from radar images provided by the CGIAR (Consultative Group on International Agricultural Research) Research Program on Climate Change, Agriculture and Food Security (CCAFS) for each year from 2008 to 2011, and averaged (Table 5.2). The soil chemical characteristics of the sites were determined by collecting soil samples using an auger, from 0 to 30 cm depth, at the middle and corners of each block. Soil samples were analysed at the Ugandan National Agri cultural Research Organisa-tion (NARO) Kawanda soils laboratory (Table 5.3).

Agronomic Evaluation of Dessert Banana Cultivars 39

Tissue culture plantlets of the cultivar ‘FHIA-17’ were obtained from the Inter-national Transit Centre (ITC), Leuven, Belgium and multiplied at the Agrobiotech tissue culture laboratory at Bujumbura, Burundi. Plantlet hardening was done at the Institut de Recherche Agronomique et Zootechnique (IRAZ) nurseries in Burundi. Suckers of the cultivars ‘Gros Michel’, ‘Ikigurube’, ‘ITC0680’, ‘Yangambi Km5’, ‘Kamaramasenge’ and ‘Prata’ were obtained from the IRAZ germplasm collection at Mashitsi. Fifteen plantlets of each variety, in three replicates of five plantlets, were planted out on the sites in a randomized design

(Carlier et al., 2003). Not all of the cultivars were planted at each site (Table 5.4). Plants were spaced at 3 × 2 m, providing a density of 1667 plants/ha. The planting hole was 60 × 60 × 60 cm. Decomposed cow manure was added into each of the holes at plant-ing, at 10 kg/hole. Weeding was done at monthly intervals. De-suckering and de- leafing (of dead leaves) were carried out as and when required. Some plants died after planting owing to extreme heat and these were replaced promptly where possible, either with new plantlets or with suckers from surviving mats of the same cultivar type in the trial. Three plants were kept per mat.

Table 5.3. Soil characteristics of the sites.

Province Site pHOrganic

matter (%)N

(%)P (mg/kg)

Ca (cmolc/kg)

Mg (cmolc/kg)

K (cmolc/kg)

Cibitoke Muyange 6.2 7.07 0.33 8.82 3.37 1.88 0.91Gitega Gisuru 5.3 6.78 0.29 6.77 0.91 0.51 0.69

Mashitsi 4.7 7.82 0.34 trace 0.25 0.03 0.04Muririmbo 4.5 10.72 0.47 3.01 0.20 trace 0.25

Kirundo Murore 5.5 10.06 0.42 trace 3.23 1.97 0.44Yaranda 5.3 5.07 0.26 trace 1.64 0.99 0.72

Table 5.1. Origin, classification and use of cultivars.

Cultivar Landrace/hybrid Subgroup Genome group Use

‘FHIA-17’ ‘Highgate’ hybrid Gros Michel AAAA Dessert‘Gros Michel’ Synthetic hybrid Gros Michel AAA Dessert‘Ikigurube’ Landrace Cavendish AAA Dessert, beer‘ITC0680’ Landrace Cavendish AAA Dessert‘Yangambi Km5’ Landrace Ibota AAA Dessert, beer‘Kamaramasenge’ Landrace Kamaramasenge AAB Dessert, beer, wine‘Prata’ Landrace Pome AAB Dessert, beer

Table 5.2. Site location, altitude and annual rainfall.

Province Site Latitude (S) Longitude (E) Altitude (masl)a Annual rainfall (mm)

Cibitoke Muyange 2°46′17″ 29°7′2″ 1162 1245Gitega Gisuru 3°22′44″ 29°52′16″ 1600 1068

Mashitsi 3°18′58″ 29°54′14″ 1646 1068Muririmbo 3°11′35″ 29°50′40″ 1682 1140

Kirundo Murore 2°32′58″ 30°14′17″ 1632 1162Yaranda 2°30′42″ 30°6′53″ 1409 1162

amasl, metres above sea level

40 M. Kamira et al.

Mulching (with grass) was done at the begin-ning of each dry season. Where necessary, forked wooden sticks were used to provide support for the plants to prevent them from toppling over.

Data on growth and yield were collected from the plant and ratoon crop cycles at flowering and at harvest. Variables measured at flowering were: days from planting to flowering (only measured using plants that were not replaced); pseudostem height; pseudostem girth at 1 m above soil level; and number of functional leaves. Variables measured at harvest were: days from planting to harvest (only measured using plants that were not replaced); bunch weight; number of hands/bunch; total number of fruits; length of fruits; and the girth of fruits. For descriptions of how each trait was measured, see Carlier et al., (2003).

Statistical analysis was carried out using the R language and environment (R Devel opment Core Team, 2010) and the R packages lme4 (Bates et al., 2012), languageR (Baayen, 2011) and agricolae (Mendiburu, 2012). To account for the replication across the six sites and the pseudo-replication across crop cycles, the data were analysed using linear mixed-effects modelling, with a Gaussian distribution. Each plant trait was analysed as the response variable. The random effects were site and crop cycle, and no model selection was done on these. Fixed effects were cultivar and altitude. Model selection of the fixed effects was done by creating all possible models (a ‘null’ model using the intercept, cultivar only, altitude only, cultivar and altitude as additive effects, and cultivar and altitude as

interacting effects), comparing them with one another and choosing the model with the lowest Akaike Information Criteria (AIC) value.

The model fit was assessed by plotting the residuals. Data points outside the biologically acceptable range were removed as necessary. The following traits were square root transformed: pseudostem girth, bunch weight, number of hands/bunch and total number of fruits. Parameter estimates with lower and upper 95% confidence intervals (CIs) were obtained using the languageR package. Because of the small sample sizes, the CIs were very large and so the tables are presented using the mean and standard deviation (sd) of the raw data. To assess whether the means of each trait, by cultivar, where significantly different from one another or not, a Tukey HSD (honestly significant difference) test was done on the output of a one-factor ANOVA, implemented using the ‘agricolae’ package.

Average annual yield (t/ha) for each cultivar was calculated as: (average bunch weight over all crop cycles (kg)/1000) × (days in a year, 365/crop cycle of the plant crop) × (planting density, 1667 plants/ha); this is based on a modified version of the yield calculation in Gaidashova et al. (2008). As the first crop cycle tends to be longer, and the bunch weights of the parent plant tend to be lower than subsequent ratoon crop cycles, the average annual yield estimates are likely to be conservative. The average annual yield was calculated using cultivar averages for bunch weight and crop cycle, instead of data from individual plants, as the plants that had both crop cycle and

Table 5.4. Sites of the experiments and the cultivars planted at each site.

Site Cultivars

Gisuru ‘FHIA-17’, ‘Yangambi Km5’, ‘Kamaramasenge’, ‘Prata’Mashitsi ‘FHIA-17’, ‘Yangambi Km5’, ‘Kamaramasenge’, ‘Prata’, ‘Ikigurube’Muririmbo ‘FHIA-17’, ‘Yangambi Km5’, ‘Kamaramasenge’, ‘Prata’, ‘Ikigurube’, ‘Gros Michel’Murore ‘FHIA-17’, ‘Yangambi Km5’, ‘Kamaramasenge’, ‘Prata’, ‘Gros Michel’, ‘ITC0680’Muyange ‘FHIA-17’, ‘Yangambi Km5’, ‘Kamaramasenge’, ‘Prata’, ‘Gros Michel’, ‘ITC0680’Yaranda ‘FHIA-17’, ‘Yangambi Km5’, ‘Gros Michel’, ‘ITC0680’

Agronomic Evaluation of Dessert Banana Cultivars 41

bunch weight data were too few and highly skewed across the cultivars and sites. Because the yield estimates use cultivar averages, no statistical analyses were performed on this variable.

5.3 Results

5.3.1 Plant performance at flowering

The number of days from planting to flowering was significantly affected by cultivar only (P < 0.001). ‘Gros Michel’ and ‘Kamaramasenge’ took the least amount of time to reach shooting (476 days) while ‘FHIA-17’ took the longest (563 days) (Table 5.5).

The pseudostem height and girth at 1 m above soil level were significantly affected by an interaction between cultivar and altitude (P < 0.001). All cultivars had the tallest and thickest pseudostems at the site with the lowest altitude, Muyange, 1162 masl. Between the altitudes of 1409 and 1682 masl, the cultivars tended to grow to a lower height and a thinner girth, though this occurred on a case-by-case

basis (Plate 1). ‘Ikigurube’ was the shortest cultivar (mean height 156 cm) while ‘Gros Michel’ and ‘Prata’ were the tallest (352 and 324 cm). ‘Kamara masenge’ had the thinnest girth (35 cm) whilst ‘FHIA-17’, ‘Gros Michel’, ‘ITC0680’ and ‘Prata’ had the thickest (ranging from 48 to 53 cm) (Table 5.5).

The number of functional leaves was significantly affected by cultivar only (P < 0.001). ‘Kamaramasenge’ and ‘ITC0680’ had the lowest number of functional leaves (6.4 and 7.6, respectively), while the remaining cultivars made up a group with a greater number of leaves (ranging from 7.7 to 8.4) (Table 5.5).

5.3.2 Plant performance at harvest

The number of days from planting to harvest (the crop cycle) was significantly affected by cultivar only (P < 0.001). ‘Kamaramasenge’, ‘Yangambi Km5’ and ‘Gros Michel’ took the least amount of time to reach harvest (ranging from 612 to 621 days), while ‘Ikigurube’ took the longest (718 days) (Table 5.6).

Table 5.5. Plant performance traits of cultivars at flowering, averaged over sites. Means followed by the same letter within a row are not significantly different at P = 0.05.

Cultivar ‘FHIA-17’ ‘Gros Michel’ ‘Ikigurube’ ‘ITC0680’‘Yangambi

Km5’ ‘Kamaramasenge’ ‘Prata’

Days from planting to floweringNo. plants 57 19 17 13 86 31 29Mean 563a 476b 556ab 520ab 516ab 476b 516absd 74 106 78 91 119 69 70

Pseudostem girth (cm)No. plants 101 34 27 27 182 100 72Mean 48ab 53a 43bc 48ab 40cd 35d 53asd 12 9 9 10 12 6 8

Pseudostem height (cm)No. plants 101 34 27 27 182 100 72Mean 207c 352a 156d 271b 247b 268b 324asd 35 85 30 76 56 41 45

No. functional leavesNo. plants 101 34 27 27 182 100 72Mean 7.8a 7.9a 8.4a 7.6ab 7.7a 6.4b 7.8asd 2.1 2.0 2.1 1.8 2.4 2.2 2.4

42 M. Kamira et al.

Bunch weight was significantly affected by an interaction between cultivar and altitude (P < 0.001). ‘Yangambi Km5’, ‘Kamara masenge’ and ‘Prata’ tended to produce heavier bunches at lower altitudes, ‘Gros Michel’ tended to produce bunches with similar weights across all altitudes, while ‘ITC0680’ tended to produce heavier bunches at higher altitudes (Plate 2). ‘Ikigurube’ was only grown at two sites (Mashitsi and Muririmbo), both at an altitude greater than 1600 masl, and there was a significant difference between the bunch weights at these sites. ‘FHIA-17’ had the heaviest bunches (26.7 kg). This bunch weight was almost 11 kg heavier than the bunch weights of the cultivars ‘Yangambi Km5’, ‘Gros Michel’, ‘Prata’ and ‘ITC0680’, which formed the next group (weight range 11.9 to 15.7 kg).

‘Kamara masenge’ and ‘Ikigurube’ had the lightest bunch weights (8.0 and 9.5 kg, respectively) (Table 5.6).

Average annual yield was calculated using cultivar averages for crop cycle and bunch weight and thus the difference between cultivars was not statistically tested. ‘FHIA-17’ had the greatest average annual yield of 23.6 t/ha. ‘ITC0680’ had the next greatest average annual yield (14.2 t/ha), ‘Gros Michel’, ‘Prata’ and ‘Yangambi Km5’ had similar yields to one another (12.7 t/ha, 12.6 t/ha and 11.7 t/ha respectively), while ‘Kamaramasenge’ and ‘Ikigurube’ had the lowest (8.0 and 8.1 t/ha respectively).

The number of hands per bunch was significantly affected by cultivar only (P < 0.001). ‘Gros Michel’, ‘Yangambi Km5’ and ‘FHIA-17’

Table 5.6. Plant performance traits of cultivars at harvest. Means followed by the same letter within a row are not significantly different at P = 0.05. The average annual yield (t /ha) was calculated using the following formula: average bunch weight over all crop cycles (kg/1000) × (days in a year, 365/crop cycle of plant crop) × (planting density, 1667 plants/ha) and was not subject to statistical analyses because cultivar averages were used rather than individual data points.

Cultivar ‘FHIA-17’ ‘Gros Michel’ ‘Ikigurube’ ‘ITC0680’‘Yangambi

Km5’ ‘Kamaramasenge’ ‘Prata’

Average annual yield (t/ha)Mean 23.6 12.7 8.1 14.2 11.7 8.0 12.6

Bunch weight (kg)No. plants 67 14 11 11 119 76 47Mean 26.7a 13.0bc 9.5cd 15.7b 11.9bc 8.0d 13.3bcsd 9.8 2.4 3.0 6.1 4.0 3.5 3.4

Days from planting to harvest (crop cycle)No. plants 55 13 16 8 67 26 24Mean 688ab 621b 718a 670ab 620b 612b 641absd 74 98 61 59 122 68 81

Fruit girth (cm)No. plants 67 14 11 11 119 76 47Mean 12.7a 11.4ab 11.2ab 12.8a 10.1bc 8.4c 10.7bsd 1.8 1.9 2.4 1.1 2.0 2.9 1.9

Fruit length (cm)No. plants 67 14 11 11 119 76 47Mean 15.2a 14.1abc 13.5abc 14.5ab 11.9cd 9.8d 12.9bcsd 2.6 2.5 2.7 2.6 2.4 2.4 2.6

Number of fruits/bunchNo. plants 67 14 11 11 119 76 46Mean 171a 166ab 105de 145abc 127bcd 91e 111cdesd 55 52 30 17 52 51 29

Number of hands/bunchNo. plants 67 14 11 11 119 76 47Mean 10.8a 9.1ab 7.0c 8.7bc 9.3ab 8.3bc 8.5bcsd 1.9 3.3 2.0 2.1 2.3 2.4 1.7

Agronomic Evaluation of Dessert Banana Cultivars 43

had the most hands per bunch (ranging from 9.1 to 10.8), while ‘Ikigurube’, ‘Kamara-masenge’, ‘Prata’ and ‘ITC0680’ had the least (ranging from 7.0 to 8.7 hands) (Table 5.6).

The number of fruits per bunch was significantly affected by an interaction between cultivar and altitude (P < 0.001). ‘FHIA-17’, ‘Yangambi Km5’ and ‘Prata’ tended to produce more fruits at lower altitudes, while ‘ITC0680’ tended to produce more fruits at higher altitudes. For the remaining cultivars, altitude either increased or decreased the number of fruits per bunch on a case-by-case basis (similar to bunch weight, Plate 2). ‘ITC0680’, ‘Gros Michel’ and ‘FHIA-17’ had the greatest number of fruits per bunch (ranging from 145 to 171), while ‘Kamaramasenge’, ‘Ikigurube’ and ‘Prata’ had the least (91 to 111) (Table 5.6).

The length and girth of a fruit were both significantly affected by an interaction between cultivar and altitude (P < 0.001). Finger girth tended to be a more stable trait across altitude than finger length (Table 5.6). ‘Gros Michel’, ‘Yangambi Km5’ and ‘Kamara masenge’ tended to produce longer fruits at lower altitudes, while ‘FHIA-17’, ‘Ikigurube’ and ‘Prata’ tended to produce a stable fruit length across altitude, and ‘ITC0680’ tended to produce longer fruits at higher altitudes (Plate 3). ‘Ikigurube’, ‘Gros Michel’, ‘ITC0680’ and ‘FHIA-17’ had the long-est fruits (ranging from 13.5 to 15.2 cm); ‘Ikigurube’, ‘Gros Michel’, ‘FHIA-17’ and ‘ITC0680’ had the thickest fruits (ranging from 11.2 to 12.8 cm); and ‘Kamaramasenge’ and ‘Yangambi Km5’ had the shortest (9.8 and 11.9 cm, respectively) and thinnest (8.4 and 10.1 cm, respectively) (Table 5.6).

5.4 Discussion

The agronomic performance of the introduced improved hybrid dessert banana ‘FHIA-17’ and six commonly grown ‘local’ dessert banana cultivars was evaluated in up to six sites across Burundi.

The improved hybrid cultivar ‘FHIA-17’ significantly outperformed the other cultivars as it had the heaviest bunch weight and

an average length crop cycle compared with the other cultivars. Using this information, average annual yield (t/ha) for ‘FHIA-17’ was calculated as 23.6 t/ha using a modified and conservative version of the yield calculation that appears in Gaidashova et al. (2008). This average annual yield is much greater than the estimated annual banana yield currently attained in Burundi of 5 t/ha (FAOSTAT, 2010). ‘FHIA-17’ was also in the group of cultivars with the most hands and fruits per bunch, and the fruits were long and thick. Furthermore, ‘FHIA-17’ had a robust, short and thick pseu-dostem, which is a desirable trait in East Africa, where bananas are often cultivated in hilly conditions (Vigheri, 1997) and the short plant stature makes the removal of the early male buds – to prevent insect vector transmission of Xanthomonas wilt – easier.

This strong agronomic performance of ‘FHIA-17’ has also been demonstrated in Uganda (Nowakunda et al., 2000), Kenya (Njuguna et al., 2008), Rwanda (Gaidashova et al., 2008) and Mozambique (Uazire et al., 2008), where it outperformed all other banana cultivars. The agronomic performance of ‘FHIA-17’ in the Burundi experiment described in this chapter is, however, lower than the performance attained in most of these other experiments. For instance, in Rwanda, at an altitude of 980 masl, ‘FHIA-17’ had a crop cycle of 462 days and a mean bunch weight of 53.4 kg (Gaidashova et al., 2008), and in Kenya, at an altitude of 1500 masl, ‘FHIA-17’ had a crop cycle of 565 days and a mean bunch weight of 36.03 kg (Njuguna et al., 2008). In Mozambique, at an altitude of 12 masl, ‘FHIA-17’ had a shorter crop cycle (461 days) than was attained in Burundi, but also produced lighter bunches (21.5 kg) (Uazire et al., 2008).

The next best performing cultivars in the trials were ‘ITC0680’, ‘Gros Michel’, ‘Prata’ and ‘Yangambi Km5’. These cultivars had crop cycles that were shorter than that of ‘FHIA-17’ (but not significantly so) and were the group that had the second heaviest bunch weights after ‘FHIA-17’. Both ‘Gros Michel’ and ‘ITC0680’ tended to perform equally well or better at higher, rather than lower, alti-tudes. ‘Gros Michel’ has been noted as grow-ing well at higher altitudes around Lake

44 M. Kamira et al.

Victoria (above 1100 masl) (De Langhe, 1986). ‘ITC0680’, though, belongs to the ‘Cavendish’ subgroup and cultivars of this subgroup are generally grown in low-lying (less than 800 masl) coastal regions (Karamura et al., 1998). These results, which are contrary to general expectations, may be a result of the absence of sites at altitudes lower than 1162 masl, and to a lack of replication among sites at the lower altitudes, i.e. there was only one site at 1162 masl and one site at 1409 masl, compared with four sites above 1600 masl. Thus, strong differ-ences between high and low altitude sites may simply represent differences due to site (e.g. management practices, local weather pat-terns, observer effect), rather than to altitude.

The cultivars with the poorest perfor-mance were ‘Ikigurube’ and ‘Kamaramasenge’. The crop cycles for these cultivars were not significantly different from that of ‘FHIA-17’, but the bunch weights were much lower, at 9.5 kg and 8.0 kg respectively. The corresponding average annual yields for these cultivars were low, at 8.1 t/ha and 8.0 t/ha, respectively. Cultivars in the AAA ‘Cavendish’ subgroup, such as ‘Ikigurube’, and AAB genome culti-vars such as ‘Kamaramasenge’, are generally considered to be lowland varieties (Karamura et al., 1998) and this may account for the rela-tively poor performance of these cultivars at the comparatively high altitude sites used in these trials. Although the average annual yields obtained for these cultivars are low, they are still greater than the current annual yield for banana production in Burundi. This improved performance may be the result of improved agricultural practices, such as mulching, as taught by CIALCA.

A key reason for introducing improved hybrids into production systems is their increased resistance to, or tolerance of, pests and diseases because of their genetically diverse pedigrees. Pests and diseases were not specifically measured during these exper-iments, though they are thought to be low/absent at the trial sites that were used. It is, however, possible that pests and diseases may have been partially responsible for the lower performance of the commonly grown local cultivars compared with that of ‘FHIA-17’. For instance, ‘FHIA-17’ has demonstrated resistance/tolerance to Fusarium oxysporum

f.sp. cubense race 1 (Nowakunda et al., 2000; Orjeda et al., 2000), Mycosphaerella fijiensis (FHIA, 1993; Nowakunda et al., 2000; Molina Tirado and Castaño Zapata, 2003); M. eumusae (Mourichon et al., 1997; Sulliman et al., 2012) and the banana weevil (Nowakunda et al., 2000). ‘FHIA-17’ may, therefore, be a good cultivar to use in areas where these pests and diseases are present. But is susceptible to Xanthomonas campestris pv. musacearum (Tripathi et al., 2008), banana bunchy top virus (BBTV) (Gaidashova et al., 2008; Molina et al., 2010) and the nematode Radopholus similis (Viaene et al., 1997; Moens et al., 2005).

A major impediment to the wider uptake of ‘FHIA-17’ may be a lack of consumer acceptability. For example, of 200 respondents in Mozambique, 46% thought it did not smell good, 38% thought it was not similar to tradi-tional varieties, 64% rated it as ‘not ideal’ and 53% would not continue to consume it (Uazire et al., 2008). Similar consumer acceptance results have been reported around the world for the FHIA hybrids, and the hybrids of other breeding programmes (Molina et al., 2010).

Nevertheless, in Burundi, ‘FHIA-17’ is appreciated for its short height, sweet fla-vour and large finger size, and is gradually replacing the most common dessert bananas – ‘Kamaramasenge’ and ‘Gros Michel’. ‘Gros Michel’ and ‘Kamaramasenge’ are widely cultivated in the rural areas surrounding Bujumbura, the capital of Burundi, and these zones are now increasingly affected by Xanthomonas wilt. ‘FHIA-17’ is grown by farmers in Kayanza, Ngozi, Karusi, Kirundo, Muyinga and Makamba provinces. In paral-lel, top government officials are also involved in its cultivation in Ngozi and Muyinga provinces.

‘FHIA-17’ is sold as a dessert banana in the Bujumbura markets, where a bunch is sold for around 10,000 Burundian Francs (1 US$ = 1494 BIF, January 2013) (J.-P. Kanyaruguru and E. Njukwe, December 2012, Bujumbura, per-sonal observation). The ‘Garukirigitoke Farmers’ Association’ in Muyinga province, eastern Burundi, sells FHIA bunches to factories in Tanzania where they are processed into banana juice and banana chips (J.-P. Kanyaruguru and E. Njukwe, December 2012, Bujumbura, personal observation). These farmers, trained

Agronomic Evaluation of Dessert Banana Cultivars 45

to use macropropagation technology by CIALCA, have installed four macropropa-gation units; in December 2012, they had over 8 ha of both ‘FHIA-17’ and ‘FHIA-25’varieties established. They recently started selling plantlets of FHIA varieties to farmers in neigh-bouring provinces and are involved in farmer-organized training on macro propagation and field management practices led by NGOs and the Provincial Department for Agriculture and Livestock (DPAE).

With an ever-increasing interest in ‘FHIA-17’, this cultivar is now also multiplied using macropropagation techniques in Makamba Province by the NGO (non-government organization) CADEK (Collectif des Associations pour le Développement Economique de la Paroisse Kibago), for its own use, and around Bujumbura by the NGO Floresta as an income-generating activity. Floresta has already sold over 1700 ‘FHIA-17’ plantlets. A remaining bottleneck is the higher cost of macropropagation-derived FHIA plantlets (1200 BIF) compared with suckers of local cultivars (500 BIF). The higher cost of macropropagation-derived FHIA plantlets may be attributed to the scarcity of FHIA varieties and to the high demand for them. FHIA suckers are sold for 800–1000 BIF. In con-trast, macropropagation-derived plantlets of ‘Incakara’ and ‘Sohokunkorere’ (local AAA-EA cultivars) are sold for only 700 BIF by Muyinga

farmers. With technical support from CIALCA, Floresta received financial support from the governments of Belgium, the Netherlands and USA, while CADEK received financial support from the government of Italy to expand macropropagation activities. With the support of the Belgian government, the NGOs Concern World wide in Kirundo and Caritas International Belgique in Mwakiro and Muyinga are also promoting the false decapitation technique for the production of healthy ‘FHIA-17’ planting material. The pri-vate tissue culture laboratory Phytolabu, based in Bujumbura, has also received mate-rial and technical support from the govern-ment of Belgium to expand and produce more tissue culture-derived banana planting material as starting stocks to establish new fields free of Xanthomonas wilt.

Because of the high agronomic perfor-mance of improved hybrids, the govern-ment of Burundi has ordered a large amount of FHIA planting material for distribution throughout the regions. Donors have also shown interest in fast-tracking the distribu-tion of healthy ‘FHIA-17’ plantlets to over-come food insecurity in Burundi. Wide-scale cultivation of ‘FHIA-17’ in Burundi may contribute to the sustainable production of a dessert banana cultivar in the region and to food and income security for the population.

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