AMMI analysis of G × E interaction and identification of fodder cowpea genotypes for phosphorus deficient condition

Phosphorus (P) deficiency affects the productivity of fodder legumes and smallholder farmers do not have the resources to purchase Phosphate fertilizers. An alternative solution to the problem of P deficiency is the development of genotypes with the ability to perform well in P-deficient soils. In the present investigation, genotype × environment interaction (GEI) was assessed in 45 fodder cowpea genotypes for green fodder yield over two seasons under four phosphorus levels to identify stable high-yielding genotypes. Combined analysis of variance revealed that environmental factors (76.20 %) were the primary source of variation, followed by genotype (14.89 %) and G × E effects (8.47 %). The AMMI model for G × E interaction showed that the first two interaction principal components (IPCA1 and IPCA2) were highly significant. IPCA1 and IPCA2 contributed 51.00 % and 15.50 % of total G × E interaction variability. AMMI biplot showed differential interaction of the genotypes in different environmental conditions. Based on these two significant IPCAs, AMMI stability value (ASV) was calculated, that ranged from 0.21 to 7.24. In rabi season, genotypes MFC-18-4, MFC-09-1, IFC-9304, UPC-804, MFC-18-8, F-6R-211-184-2 were found to be stable for green fodder yield in phosphorus deficient condition. Genotypes UPC-2001, EC-402154 and UPC-618 were suitable for phosphorus deficient condition during kharif season and recorded stable green fodder yield. Based on ASV parameter, UPC-2001, UPC-805, UPC-804, UPC-4200, FD-739 were identified as the most stable and high-yielding genotypes. Identifying such phosphorus-efficient genotypes can ensure improved yields despite lower phosphorus inputs, reducing the cost for farmers and making agriculture more economically sustainable in resource-limited environments.