Evaluation of maize for dual-purpose traits across water-regime-diverse environments using multi-trait and G×E analyses

In Mediterranean agriculture, increasing climate variability calls for dual-purpose maize hybrids that perform well for both silage and grain yield under different irrigation regimes. This study evaluated seven maize hybrids (four candidate and three commercial checks) across eight environments (irrigated and non-irrigated trials in Antalya and Aydın, Türkiye, over 2022 and 2023). Using a randomized complete block design with two replications, we assessed traits including forage yield (FY), dry matter yield (DMY), plant height, flowering, senescence, and grain yield (GY). Mixed model analysis revealed that environments explained most of the variation in FY (81.2%), DMY (81.3%), and GY (85.5%). Genetic variance ranged from 2.8% (GY) to 6.8% (FY), while genotype × environment (G×E) interactions contributed 5.9-6.9%. Repeatability values were high: 0.90 for FY, 0.71 for DMY, and 0.80 for GY.Hybrid C3 showed the highest FY and DMY overall, ranking in the top three in all environments, especially under irrigation. H3 performed well in non-irrigated trials, showing greater stability. Plant height correlated strongly with FY and DMY (r = 0.48-0.79), supporting its use in indirect biomass selection. G×E interactions, visualized with AMMI and GGE biplots, revealed crossover patterns. A Dual-purpose Index based on standardized FY, DMY, GY, and moisture loss ranked C3 and H3 as top performers. This study highlights the importance of multi-trait, multi-environment selection. Hybrids C3 and H3 are promising for Mediterranean regions, offering high productivity, adaptability, and stress resilience.