The yield of cowpea varieties is affected by environmental variability. Hence, candidate varieties must be tested for yield stability before release. This study assessed the impacts of genotypes, environments, and their interaction on the performance of elite cowpea lines for key adaptive, grain yield, and associated traits across different locations. A total of 42 elite genotypes were evaluated in five Nigerian environments, representing various savanna ecologies, during the 2021 growing season. The experimental design employed was an alpha lattice arrangement, with each genotype replicated three times. The results revealed significant differences among genotypes, environments, and genotype-by-environment interaction (G × E) for most traits, including days to maturity, 100-seed weight, and grain yield. The genotype and genotype-by-environment interaction (GGE) biplot showed G21 (IT14K-2111-2) and G25 (IT15K-2386-1) as the most stable genotypes across the five environments, G41 (IT11K-61-82) was best adapted to Ibadan and Shika, G5 (245-1) was best adapted to Bagauda and Gumel, and G30 (IT16K-2365-1) was best adapted to Bauchi. G21 (IT14K-2111-2) and G25 (IT15K-2386-1) could be recommended across the five test environments, whereas G41 (IT11K-61-82), G30 (IT16K-2365-1), and G5 (245-1) were specific to the adapted environments.

In the West African sub-region, intercropping is a critical element in cowpea product profiles. This study aimed to investigate the impact of intercropping cowpea with pearl millet on genetic correlations, heritability, and response to selection. Thirty-five cowpea genotypes and one pearl millet variety were used to create three cropping patterns: sole cowpea, 1:1 (one row of millet to one row of cowpea), and 2:4 (two rows of millet to four rows of cowpea). Split-plot experiments were conducted for two years with cropping patterns considered as the main plots and genotypes as sub-plots. Data were captured on grain yield (GY), 100 seed weight (Hsdwt), pod weight (Pdwt), fodder weight (Fdwt), and harvest index (HI). Genotype, cropping pattern, year, and genotype-by-cropping pattern interactions were significant for most of the traits. Higher heritability and predicted genetic advance were depicted under sole cropping rather than in the intercropped systems. High positive genetic correlations (r_g ≥ 0.9) were obtained between cropping patterns. Genetic correlations among traits were higher under sole cropping than in the intercropping. Path analysis portrayed the HI as having the highest significant and positive direct effect on GY. This study identified short duration cowpea genotypes that are stable and adapted to unique cropping systems.

This study assessed the impacts of genotypes, environments, and their interaction on the performance of elite cowpea lines for key adaptive, grain yield, and associated traits across different locations. A total of 42 elite genotypes were evaluated in five Nigerian environments, representing various savanna ecologies during the 2021 growing season. The experimental design employed was an alpha lattice arrangement, replicating each genotype three times. The results revealed significant differences among genotypes, environments, and genotype-by-environment interaction for most traits, including days to maturity, 100 seed weight, and grain yield. GGE biplot showed G21 (IT14K-2111-2) and G25 (IT15K-2386-1) as the most stable genotypes across the five environments, G41(IT1K-61-82) was best adapted to Ibadan and Shika, G5 (245-1) was best adapted to Bagauda and Gumel while G30 (IT16K-2365-1) was best adapted to Bauchi. G21 and G25 could be recommended across the five test environments while G41, G30 and G5 are specific to the adapted environments.