Abstract:
Yield in legumes is the result of many plant processes, which are
usually expressed in yield and have been shown to be affected by
management, genotype and environment. The objectives of this study
were to assess the extent of genotype x environment interaction and to
select the stable cowpea genotypes in Ugandan environments over
seasons. Seventy-two cowpea genotypes were evaluated for yield in
three locations and two seasons in Uganda. The yield data were
subjected to analysis of variance and additive main effects and
multiplicative interactions (AMMI) analysis. The results showed a
highly significant (P<0.001) genotype by location and by year
(season) interaction effects for grain yield, with 69.16% of the total
variation attributable to environmental effects, 5.36% to genotypic
effects and 12.74% to G x E interactions effects. Genotype MU9 had
the highest yield (854.68 kgha-1) but was only adapted to specific
environments (Arua 2015B and 2016A). Hence, genotypes WC 30,
NE 45, NE 31, NE 51 which were equally high yielding, stable and
adapted to the tested environments, and should be recommended for
genetic improvement of cowpea germplasm in Uganda
