Yield adaptability and stability of semi-erect cowpea genotypes in the Brazil Northeast Region

The objective of this work was to evaluate the adaptability and the stability of the grain yield of 20 semierect cowpea genotypes, using the additive main effect and multiplicative interaction model. The trials were carried out in 16 environments of the Northeast Region of Brazil. The genotypes, environments and genotype x environment interaction, as well as the first three axes of the principal components analysis ( PCA) were significant. The first two axes of the PCA explained 55.11% of the sum of squares of the genotype x environment interaction, corresponding to 83.20% of the pattern of genotype x environment interaction. TE97-321G-4, EVX-92-49E and EVX-63-10E lines were highly adaptable, but only the last one was highly predictable. BRS Guariba cultivar as well as EVX-92-49E and TE97-321G-4 lines best express their genetic potential in environments of high yield.