Assessment genotype x environment interactions for grain yield in maize hybrids using AMMI and GGE biplot analyses

Seventeen hybrid maize genotypes were evaluated at four locations (Yenişehir- Marmora Region; Bornova-Aegean Region; Ceyhan-Mediterranean Region; Seyhan- Mediterranean Region) in 2005 and 2006 cropping seasons under irrigated conditions in Turkey. The analysis of variance for grain yield of the 17 hybrid genotypes tested in eight environments showed mean squares of environments, genotypes and GEI (genotype x environment interaction) were highly significant and accounted for 62.1%, 12.5% and 25.4% of treatment combination sum of squares, respectively. To determine the effects of GEI on yields, the data were subjected to additive main effects and multiplicative interaction (AMMI) and the GGE biplot analysis. Although mean grain yield of the check cultivar G12 was higher than those of experimental hybrids, difference between G12 and G16, which is the most stable genotype according to AMMI and GGE biplot, was insignificant. It is understood that the experimental hybrid maize G16 can be proposed in reliably for growing by the farmers. Also, it was detected that only the test environment E3 (Ceyhan location) may be sufficient for deciding about which experimental hybrids can be recommended, instead of four test locations (Ceyhan, Seyhan, Bornova and Yenişehir) in this study. In addition, it is concluded that there is no difference between the AMMI and GGE biplot analysis in evaluation of experimental maize hybrids and test environments in this research and that both methods can be used successfully in determining suitable locations for maize hybrids in the environments under Mediterranean climate conditions.