Maize (Zea mays L.) Agro-Physiological Response to Potassium and Iron Fertilizer under Water Deficit Stress

This research was conducted to evaluate effect of potassium and iron fertilizers on agro-physiological traits affected different irrigation regime of corn in Shahryar (Tehran province, central of Iran) via a split-split plots arrangement based on randomized complete blocks design with three replications during 2015. The main plot included different irrigation regime (Normal irrigation and stop irrigation at grain filling period). Sub plot consisted different level of K2O (0, 25, 50 kg.ha-1), from water soluble potassium sulfate source. Sub-sub plot included Fe-EDDHA that apply as fertigation 2 kg.ha-1, foliar application Fe-EDTA 2 kg.ha-1, and no iron fertilizer application as control. Application of Fe-EDDHA as fertigation and Fe-EDTA as foliar application in normal irrigation increased corn seed yield from 5232 kg.ha-1 in control to 6622 and 6464 kg.ha-1 respectively but in water deficit situation were not effective. In normal irrigation, application 25 and 50 kg.ha-1 soluble potassium sulfate increased corn seed yield from 5294 kg.ha-1 in control to 6975 and 6048 kg.ha-1 respectively. Under water deficit stress application of 25 and 50 kg.ha-1 soluble potassium sulfate increased corn seed yield from 3921 kg.ha-1 to 4794 and 4807 kg.ha-1 respectively. Maximum corn seed yield was achieved when 25 kg.ha-1 soluble potassium sulfate and Fe-EDDHA applied together in 6392 kg.ha-1. Application soluble potassium sulfate and iron fertilizers increased chlorophyll a, b, and total content in different irrigation regimes. However fertigation of soluble potassium sulfate along with Fe-EDDHA was more efficient to improve chlorophyll a, b, and total and seed yield in water deficit situation.