Assessment of the impact of deficit irrigation on seed corn yield and its components in Miyandoab region

Deficit irrigation is one of the major methods for water use optimization in irrigatinglands. The main aim of this research is two fold: to evaluate the impact of deficitirrigation, first on the yield its components by measuring the increase the yield and thedecrease in the amount of water usage per hectare, and secondly on the different growth stages of the seed corn. RCBD was used as the experimental design and repeated four times. The plots of irrigation intervals were at three levels: 100 mm, 130 mm and 160 mm of cumulative evaporation from class A pan. The sub plots were different amounts of water requirements: 50%, 75% and 100% of total required water. Statistical calculations including simple analysis of variance, complex analysis and mean comparisons were performed for the traits: seed yield, ASI, corncob length, plant height, number of seeds in row, 1000 kernel weight and the percentage of green coverage. The results of the complex analysis showed that the effects of irrigation intervals (the main factor) and water requirement (the sub factor) had a significant difference regarding seed yield, ASI, corncob length, plant height, number of seeds per row and 1000 kernel weight. The interaction impact between irrigation intervals in water requirement became significant only for ASI at statistical 5% level. It is recommended in the region where the trial was conducted the irrigation intervals to be 15 days. With regard to the low decrease in yield and other yield-dependent traits in 75% water requirement relative to 100% water requirement, it is recommended to use 75% water requirement for irrigation of corn in the region in order to save water and cultivate more lands with the saved water.