Yield stability studies in indigenous and exotic maize hybrids under genotype by environment interaction

Identification of superior maize hybrids for targeted environment is very complex due to the existence of lager genotype-by-environment interaction (GEI). This study considered G × E interaction of nine genetically diverse, indigenous and exotic maize hybrids with eleven environments of Pakistan for grain yield in two consecutive spring seasons (2017 and 2018) under randomized complete block design in split plot arrangement with two replicates. Combined analysis of variance showed that environments, genotypes and their interactive effects were significant (p<0.01) for grain yield. Average grain yield of the maize hybrids ranged from 8369 kg ha-1 for YH-5140 to 11066 kg ha-1 for FH-1046. The first two principal components (PC1 and PC2) were used to produce two-dimensional genotype + genotype × environment interaction (GGE) biplot that accounted for 62.3% and 18.69%, respectively. Results showed a crossover type of interaction between hybrids and environments, with differential performance of maize hybrids across test environments. The "which won where" GGE biplot proposed the presence of two maize mega-environments with two wining hybrids i.e., FH-1046 and YH-5482. The "mean vs. stable" biplot suggested that FH-1046 was the most productive hybrid but was less stable, whereas YH-1898 was the most stable hybrid across the test environments. The "discriminativeness vs. representativeness" biplot showed that Depalpur was the most ideal test environment while Jhang was the most discriminative location. Highly productive but less stable maize hybrids across test environments are proposed for cultivation in those test environments/locations wherever they performed outstandingly. (author)