Phenotypic Variations of Drought Tolerance Parameters in Maize (Zea mays L.) under Water Stress at Vegetative and Reproductive Stages

Two field experiments were conducted at Shambat and Medani in Sudan under water stress in vegetative and reproductive growth stages during the season (2003/2004). The objective of the study was to assess phenotypic variability and phenotypic correlation between drought tolerance parameters in maize genotypes. A split-plot layout within randomized complete block design with three replications was used for the experiment. Fifteen genotypes of maize were examined through the study. The effect due to genotypes x location was highly significant for all drought tolerance parameters studied. Highly significant and favorable correlation for Yw with SSI2, SSI3, GMP2, GMP3, STI2 and STI3, while highly significant and negative with Yd2/Yw and Yd3/Yw. Based on the result's drought stress at vegetative and reproductive stages of maize results in a drastic reduction in grain yield, and the strong positive correlation of Yw with SSI, GMP and STI, indicates that selection for high values of these parameters improves yield under stress and non-stress environments. Drought tolerance parameters can be used for improving grain yield and facilitate further efforts in maize breeding programs