Adaptation and stability of cowpea (Vigna unguiculata (L.) Walp) bean cultivars in the tropical dry forest of Colombia

Cowpea (Vigna unguiculata (L.) Walp) is a source of low cost protein for food, and is currently used in family farming in northern Colombia. The aim of this study was to estimate the adaptability and phenotypic stability of the grain yield (per hectare) of nine advanced lines (plus control) of cowpea and a commercial control in eight contrasting environments of the tropical dry forest of the Colombian Caribbean region. We employed five analysis methods: Eberhart and Russell, Lin and Binns, Annichiarico, Carneiro, and Nascimento et al. A completely randomized block design was used with 9 genotypes +1 control and four repetitions per environment. The analysis of variance detected significant differences in environments, genotypes and in the genotype x environment interaction, confirming that the crops have become sensitive to differences of the environments. At the same time, we forced to consider adaptability and stability for the selection of the best genotype. The five methods of analysis coincided with identification of line L-019 as the best genotype due to its grain yield, adaptability and phenotypic stability. Therefore, L-019 is a new planting alternative for family agriculture of cowpea producers in the Colombian Caribbean.