Effect of Water Deficit Stress and Nitrogen on Yield and Compatibility Metabolites of Two Medium Maturity Corn Cultivars

In order to study the effect of water deficit stress and nitrogen on yield and compatibility metabolites in two hybrid corn cultivars, an experiment was conducted at the experimental farms of Tarbiat Modarres and Kermanshah Razi Universities. The experimental design was randomized complete block with treatments organized following a split-factorial with three replications. Drought stress at three growth stages (vegetative, reproductive and both vegetative and reproductive) and without water deficit or control were randomized to the main plot units. Combination of two levels of nitrogen fertilizer (100 and 200 kg/ha) and two maize varieties (S.C. 647 and T.C. 647) were appled to the subplot units. The results showed that water deficit stress, nitrogen and cultivar had significant effects on grain yield. Water deficit stress at vegetative phase had significant effect on leaf soluble proteins and was reduced in stress treatments as compared with the control. Soluble protein in the treatments with full fertilizer was more than nitrogen deficit treatments. At the end of each phase of stress (growth stage) water deficit induced a significant increase of proline in leaves. Nitrogen levels showed positive correlation with the loaf proline Content. Water deficit stress led to a significant decrease of chlorophyll content in examined cultivars. Water deficit had a significant effect on free amino acid content of leaf at the end of reproductive stage.