Correlation and regression between traits and grain yield in maize hybrids under normal and stress conditions

This experiment was conducted to study of changes yield and yield components in 22 corn hybrids. The experiment was split plot by using randomized complete block design with three replications under stress and non-stress during 2013 and 2014 at the Research Station Agriculture, Islamic Azad University of Tabriz, Iran. Treatments consisted of two irrigation levels (Irrigation after 70 mm evaporation from class A evaporation pan and irrigation after 140 mm evaporation from class A evaporation pan at the beginning of the Tasseling) as main plots and 18 maize hybrids and 4 maize varieties as sub–plots. Combined analysis in two years showed that genotype × water stress interaction had significant difference for most of measured traits. Genotype L2 × K1263/1 was the highest yield in the 6/38 kg under normal conditions and also genotype L3 × A679 was the highest yield under drought conditions in the 3/82 kg. The results of correlation analysis showed the number of kernels per row and numbers of grains per ear have a maximum significant positive correlation under stress and non-stress conditions. Results of step wise regression in non-stress conditions, 100 seed weight, number of kernels per ear, number of leaves and plant height and under stress conditions 100 grain weight, number of kernels per ear and plant height remained. Path analysis showed that the non-stress conditions and under stress conditions number of number of grains per ear had a direct effect on grain yield.