Genetic and Environmental Effects on Nodulation and Yield Among Selected Cowpea (Vigna unguiculata [L.] Walp) Genotypes in Uganda

This study evaluated the performance of 35 cowpea genotypes using a 5 × 7 alpha lattice design across seven test environments in Uganda, focusing on genotype-environment interactions affecting nodulation capacity and yield performance. The research used additive main effect and multiplicative interaction (AMMI) analysis to assess genetic and environmental effects on cowpea productivity. Results showed that environmental effects were the largest contributor to variation in nodulation and seed yield compared to genetic and genotype-by-environment interactions, with specific genotypes identified as stable performers across different environments.