Effect of Water Deficit Stress on Yield and Yield Components in Corn Using Path Analysis

This experiment was conducted to study the effects of water deficit stress on yield and yield components of four corn hybrids. The experiment was laid out in split plot using randomized complete block design with three replications. This experiment was carried out at east Azarbayjan Agriculture and Natural Resources Research Center in 2008. Treatments consisted of four irrigation levels (without stress, water stress at 6-7 leaves stage, stress at anthesis stage and stress at kernel filling stage) as main plots, and four corn hybrids (single crosses 704, 604, 500 and double cross 370) as sub-plots. Results of data analysis revealed that in general, most of the traits under stress conditions had negative and significant correlation whit grain yield. Results of stepwise regression and path analysis showed that under average conditions, selection for higher ear weight may improve yielding ability of selected genotypes. Under average conditions ear weight had greatest positive direct effect on grain yield, and positive indirect effects through ear diameter, plant high, mean stem diameter and cob weight on grain yield. Water deficit stress at 6-7 leaves stage, ear weight had greatest positive direct effect on grain yield and indirect effects through plant height, length of tassel and ear length on grain yield. Water deficit at kernel filling stage 300-kernel weight had greatest positive direct effect on grain yield, and positive in direct effects through number of grain and kernel depth on grain yield.