Environmental modeling of interaction variance for grain yield of medium early maturity maize hybrids

Abstract

The phenomenon of genotype by environment interaction (GEI) represents permanent interest for breeders, geneticists and biometricians with its practical and theoretical aspects. We investigated GEI for grain yield of medium early maturity maize (Zea mays L.) hybrids from the official variety trial network by the Department of Protection and Recognition of Varieties of the Republic of Serbia that includes experimental maize hybrids on eight sites over two years. Environmental variables explained 77.6% and 60.7% of the GEI variation for two consecutive years, respectively. Factorial regression combined with stepwise procedure revealed the model which includes variables precipitation in July (pr7), minimum temperature in May (mnt5), maximum temperature in May (mxt5) and insolation hours in April (sh4), in 2004, and environmental index (EI) and average temperature in September (mt9) in 2005, to be the most explanatory models in the region of Vojvodina (Serbia) in two consecutive years. These results provide a base for further research in GEI and stability analysis, and are a useful tool in characterizing the sub-regions of maize growing area and extending the existing results to new sites.