Stability and phenotypic adaptability by AMMI analysis in cowpea beans (Vigna unguiculata (L.) Walp.)
ABSTRACT Cowpea beans (Vigna unguiculata (L.) Walp), is the most important legume in the Colombian Caribbean and is cultivated mainly by family-economy farmers under variable environmental conditions. This demands the identification of cultivars with greater adaptation and stability, since genotype - environment interaction (GEI) hinders the process of selection and recommendation of cultivars that, because of their genetic potential, exceed the current yield (600 kg ha-1). The objective of this study was to evaluate the adaptability and stability of 10 cowpea bean genotypes of semi-prostrate habit in eight environments of the Colombian Caribbean, during the years 2017B and 2018A; using the randomized complete block design with four repetitions. The analysis was performed using the additive main effects and multiplicative interaction (AMMI) model. The results showed highly significant differences at the level of environments, genotypes and GEI. The first three axes of the interaction were significant, selecting the first two for accumulating 81.84% of the sum of squares of the genotype by environment interaction. Genotype 2 showed the greatest adaptability and stability, but its performance was slightly lower than the average; genotypes 6 and 10 presented the highest grain yields, but were influenced by the environments, with the best response in favorable environments. The best environments corresponded to VN8A and SA7B.