Survey data confirm the high level of ba-nana cultivar diversity both in the aggregate (the country) and at the microlevel (on sin-gle farms) in both Uganda and Tanzania. In Uganda, 95 banana cultivars are currently grown only by sample farmers. The major-ity of the cultivars (86 percent) are endemic to East Africa (AAA-EA genomic group).
The remaining 14 percent are composed of exotic cultivars or banana hybrids (both classified here as nonendemic) introduced into East Africa (see further descriptions in Chapter 2 and Appendix A).
An average of 23 different banana culti-vars was identified at the village level across the sampled villages in Uganda (Table 5.8).
Surveyed households grow a large number of different banana cultivars simultaneously on their farms. Farmers tend to grow two or three different use groups. On average, households grow more cultivars (in general, and in particular, of cooking types) in high-elevation areas. This finding could be asso-ciated with the larger scale of banana pro-duction in high-elevation areas. here><Table 5.8 near
Major cultivars appear to be fairly uni-formly distributed across households. That is, the cultivars most frequently grown by farmers (percentage of households) on their Table 5.8 Average number of banana cultivars per household and per village, Uganda
Elevation
All
Low High
Banana cultivars per household 6.73*** 9.07*** 6.99
Cooking cultivars per household 4.42*** 5.57* 4.55
Banana cultivars per village 22.91 24.80 23.33
Note: *** and * indicate statistical significance at the 1 percent and 10 percent levels, respectively, in the difference of means or distributions across elevations within countries.
principal banana plots are generally the same as those most widely planted (percent-age of mats). Among them, the endemic cooking bananas predominate. Even the most popular banana cultivars occupy less than 10 percent of all mats grown by all farmers surveyed, however, reflecting the high diversity of banana cultivars found within and among farms in Uganda.
Cooking types are the most frequently sold and purchased banana cultivars at the market. Thus, cooking bananas, a food sta-ple, are important generators of cash in local markets. No significant differences in average farm-gate prices and average mar-ket prices are observable among major cul-tivars sold or purchased across elevation (Table 5.9). Households in the lowlands take longer to reach the point of purchase. Bicy-cles are the most frequent means of trans-portation of banana bunches to/from point of sale/purchase. here><Table 5.9 near
A total of 120 banana cultivars were identified in the sample of Tanzanian farm-ers, of which 96 (80 percent) are endemic, 9 exotic, and 8 hybrids (see Appendix B).
Based on common use, 79 banana cultivars were classified as cooking bananas, 20 were brewing bananas, 4 were dessert bananas, and 3 were roasting types. Banana cultivars with multiple uses were also recorded. As in Uganda, the most commonly grown group
of cultivars across elevations and subregions are the endemic cooking types. In contrast to Uganda, a few exotics, such Yangambi Km 5 and the hybrid FHIA17, were also among the 20 most frequently grown culti-vars in the lowlands.
The number of banana cultivars per household in Tanzania ranges from 3 to 29, with an overall average of 10 cultivars per household. All except two farmers were found growing at least one of the endemic cultivars (Table 5.10). The number of en-demic cultivars grown per household ranges from 1 to 16, with an average of 6. The num-ber of exotic cultivars ranges from 1 to 13, with an average of 4 per banana grove. Up to four hybrids are grown, averaging less than one per grove in the highlands. here><Table 5.10 near
Banana cultivars are bundles of attri-butes related to production traits and the consumption goods the harvest produces (see Chapters 2 and 6). Each cultivar sup-plies a combination of attribute levels, and demand for attributes is specific to each farmer, varying with farmer characteristics.
Previous field research in Uganda was used to identify a set of cultivar attributes (related to phenotypic characteristics, which in turn reflect genotype, at least in part) that farm-ers consider when choosing cultivars. Farm-ers were asked to rate cultivars according to the attributes supplied in a scale of 3 (very Table 5.9 Most common banana cultivar sold, prices, and time to market,
by elevation, Uganda
Elevation
All
Low High
Households participating as sellers Most common cultivar sold (percent of all cultivars sold)
Average farm-gate price (Ush) 798.26 863.93 803.75
Households participating as buyers
Time taken to reach point of purchase (hours) 1.12*** 0.65*** 1.07
Average market price (Ush) 1,643.49 1,874.78 1,649.11
Note: *** indicates statistical significance at the 1 percent level in the difference of means or distributions across elevations within countries.
BANANA-GROWING HOUSEHOLDS AND BANANA CULTIVARS 57
good), 2 (neither good nor bad), and 1 (bad).
Average ratings of hybrid and endemic cul-tivars are compared for the households in the sample growing both types of cultivars in Table 5.11. here><Table 5.11 near
In both Uganda and Tanzania, findings support banana researchers’ observations that farmers perceive endemic bananas to be superior in terms of consumption quality characteristics. Hybrid cultivars appear to be better suited for beer making than
en-demic types, because they are used for multiple purposes in both Uganda and Tan-zania. Bred for favorable production traits, hybrids are found to yield larger bunches in Tanzania—but not among Ugandan grow-ers. Tanzanian farmers perceived hybrids as more resistant to black Sigatoka and, in both Uganda and Tanzania, weevils. Endemic cultivars were perceived to be more resistant to Fusarium wilt in Tanzania, as is expected given the genomic group.3 Though the data Table 5.10 Average number of banana cultivars per
household, by genomic group, Tanzania
Genomic group
Elevation
All
Low High
Endemic 6.5 6.6 6.5
Nonendemic
Exotic 4.0 2.6 3.7
Hybrids 0.4 0.02*** 0.3
All cultivars 10.8 9.2 10.4
Note: *** indicates statistical significance at the 1 percent level in the difference of means or distributions across elevations within countries.
Table 5.11 Average rating of endemic and hybrid bananas, by attribute, Uganda and Tanzania
Uganda Tanzania
Trait Endemic Hybrid Endemic Hybrid
Cooking quality 2.9** 2.0** 2.6** 2.1**
Suitability for beer 1.1** 1.6** 1.3** 1.7**
Bunch size (yield) 2.2** 2.9** 2.0** 2.3**
Resistance to black Sigatoka 2.0 2.4 2.3** 2.7**
Resistance to Fusarium wilt 2.5 2.7 3.0** 2.8**
Resistance to weevils 1.5** 2.4** 1.7** 2.6**
Notes: ** indicates statistical significance at the 5 percent level. In Uganda, 23 households grow both hybrid and endemic banana cultivars in their groves. In Tanzania, 50 households grow both groups of cultivars simultaneously. Rating system: 1 = bad, 2 = neither good nor bad; 3 = very good.
3 The score for Fusarium wilt among endemic cultivars clearly supports the view established in the banana lit-erature that farmers often confuse cause and effect (Gold et al. 1998, 2004). In our sample, we found strong cor-relation between the attributes “resistance to Fusarium wilt” and “resistance to weevils,” which is attributed to farmers’ misperceptions of cause, because the effect of both biotic constraints is visually similar on the plant.
do not confirm the same relationship for Uganda, it should be borne in mind that the number of farmers growing hybrids, and thus the number of observations compared, are few. A t-test comparing the expected yield losses for endemic and hybrid ba-nanas, for the farmers in Tanzania who grow both, indicates that they are on aver-age less susceptible at a 10 percent signifi-cance level. These data, though sparse, pro-vide some epro-vidence that farmers perceive benefits from the introduction of hybrids in Tanzania. The evidence is less clear in Uganda, perhaps as a consequence of the smaller volume of hybrids disseminated, differences in disease pressures, and farm-ers’ knowledge of the diseases.
In Uganda, expected yield loss distribu-tions were compared for the three biotic constraints of interest (black Sigatoka, Fusarium wilt, and weevils) by elevation across use types. The p-values of test results comparing the distributions are shown in Table 5.12.4 Data support the hypothesis that the underlying statistical distributions of expected yield losses from black Sigatoka
differ by elevation for cooking, beer, sweet, and roasting cultivars. The geographical focus of the disease is the low-elevation areas, with limited incidence in the high-lands. This pattern is less evident for Fusar-ium wilt and weevils, with no statistically significant differences being evident be-tween expected yield loss distributions for most banana use groups. The importance of altitude in the incidence and severity of bi-otic pressures that farmers perceive sup-ports biophysical studies conducted previ-ously and the sample stratification scheme (Gold, Kiggundu, and Abera 1998; Gold et al. 2004), although the data indicate that leaf spots and weevils are less important considerably above 1,200 m.a.s.l., the divid-ing line used in this study. here><Table 5.12 near