Evaluating of the Role of Soluble Potassium Sulfate and Chelated Iron on Corn Yield and Yield Components under Water Deficit Stress

Proper crop nutrition is a key factor for achieving suitable crop yield, even under drought stress conditions. To evaluate the effects of soluble potassium sulfate fertilizer and iron chelate on corn (Zea mays L.) seed yield and its yield components under water deficite stress a split split plot experiment based on randomized complete block design with three replications was caried out in Shahryar, Tehran province, in 2014. The main plots were assigned to water deficit stress and normal irrigation and subplots to soluble potassium sulfate and chelated iron. Soluble potassium sulfate levels were 0, 25, 50 kg.ha-1 K2O and iron fertilizer sprayed as Fe-EDDHA. The results showed that interaction of potassium sulfate, iron fertilizer and water deficit stress at seed milky stage was significant (P> 0.05) as to total chlorophyll, plant dry weight, thousand seed weight and corn seed yield. The application of iron, potassium and water deficit stress had also a significant effect (P> 0.01) on biological yield and number of seeds per ear, but their interactions were not significant. Application of 25 kg.ha-1 of potassium sulfate and iron chelate as foliar spray increased seed yield from 5294 kg.ha-1 in control (without fertilizer application) to 6978 kg.ha-1 and seed yield, under water deficit stress at seed milky stage, increased from 3921 kg.ha-1 in control treatment to 4794 kg.ha-1. According to the results of this study, application of 25 kg.ha-1 of potassium sulfate along with the application of iron chelate, at pre-tasseling stage, may produce acceptable yield under water deficit stress condition.