Grain yield stability analysis of maize (Zea mays L.) hybrids under different drought stress conditions using GGE biplot analysis

Drought stress is the most important environmental constraint contributing to grain yield instability of maize
(Zea mays L.). Evaluation of maize genotypes under different stresses would be useful for identifying genotypes that combine stability with high yield potential for stress-prone areas. This study was conducted to estimate grain yield stability of maize hybrids and to identify hybrids that combine stability with high yield potential across stress and non-stress environments. Seven maize hybrids were tested in three consecutive growing seasons under four irrigation regimes (E1 = well-watered; E2 = water deficit at the vegetative growth stage; E3 = water deficit at flowering; E4 = water deficit at grain-filling) at Ultan Agricultural Research Station, Moghan, Iran. Combined analysis of variance showed that environments, genotype and genotype × environment (GGE) interaction effects were highly significant. Genotype and genotype × environment analysis using GGE biplot explained 94.7% of the total grain yield variation. The GGE biplot analysis ranked maize hybrids with above-average yield across growing seasons (SC704 > SC724 > SC703 ≈ SC720 > SC647) and grain yield stability (SC700 > TWC600 > SC724). According to the variation in maize hybrids as well as G × E interaction sources, hybrids SC704 and SC724 in environments E1, E2 and E4 as well as hybrid SC647 in E3 were the superior hybrids and had better specific adaptation. The hypothetical ideal genotype's biplot indicated that hybrid SC704 had higher grain yield and yield stability and was better adapted to all the test environments.