Path analysis of yield and yield components in super-sweet maize (Zea mays L. var. Saccarata) inbred lines at drought-stress and normal conditions

To identify the most effective characteristics on grain yield, 24 super-sweet maize inbred lines were investigated under two moisture conditions (normal and drought stress) during the 2017 growing season. The experiment was carried out as a randomized complete block design with four replications. Analysis of variance for grain yield and eight agronomic characteristics showed significant differences among investigated inbred lines. Phenotypic correlations indicated that grain yield had a significant relationship with kernel number per row, ear diameter, row number per ear, and stem diameter under normal conditions, and with kernel number per row and plant height under drought-stress conditions. Stepwise multiple linear regression showed that kernel number per row, ear diameter, and stem diameter explained 72% of the variation for grain yield at normal conditions. On the other hand, cob present, plant height, ear diameter, and ear length governed 60% of the grain yield variation under drought-stress conditions. Path analysis under normal conditions revealed that kernel number per row had the highest positive direct effect (0.717) on the grain yield followed by the stem diameter (0.292) and ear diameter (0.273). In the drought stress conditions, ear diameter (0.455) and plant height (0.436) showed the highest positive direct effects on grain yield.