TOLERÂNCIA AO DÉFICIT HÍDRICO EM HÍBRIDOS INTERVARIETAIS DE MILHO

ABSTRACT In the period of planting of second-season maize, there is high climatic instability with greater probability of occurrence of water deficit. This is one of the factors that most cause reduction in maize grain yield. In this context, the aim was to identify stable, irrigation-responsive and drought-tolerant maize genotypes. The experiments were conducted in Mococa / SP and Tatui / SP, at Instituto Agronomico, in two assays, one under full irrigation conditions and the other under water stress. The experimental design was randomized blocks with 3 replicates. Male flowering, female flowering, plant height, ear height, hectoliter weight, one hundred grain weight and grain yield were evaluated. Joint analysis of variance and stability analysis were performed by the GGEBiplot method. Significant genotype and site effects were observed for all traits. Significant effects of genotype x site interaction were found for all traits except ear height and male flowering. The characteristics most affected by water deficit were male flowering, plant and ear heights and grain yield. Genotypes F2 BM709 x PopTol 2, IAC 46 x PopTol 2, F2 30K75 x PopTol 3 and F2 BM709 x PopTol 3 are considered ideotypes because of their high grain yield, phenotypic plasticity and drought tolerance.