Interactions between water stress and zinc sulphate foliar application in late stages of growth on the yield and water use efficiency in wheat

Limitation of water resources and water stress in different final growth stages appear the importance of zinc sulphate foliar application in the vegetative growth phase.To investigate the effect of water stress and zinc sulphate foliar application and its interaction on grain yield and water use efficiency, a split factorial experiment as a randomized complete block design with three replications in crops was conducted in Isfahan Kabootarabad research station at 2009-10. Water stress treatments in this experiment at three water stress levels (no water stress, water stress at flowering stage and water stress at grain filling stage in the main plots and foliar application treatments were exposed to three zinc levels (0, 2.5, and 5 mg kg-1 as ZnSO4.7H2O) and wheat cultivars including Mahdavi, Shiraz and Pishtaz were leading in the sub plots. The results showed that the difference between water stress treatments on grain yield and harvest index at the 5% probability level and in total dry matter, and grain weight and water use efficiency at the %1 probability level were significant. Increasing zinc sulphate up to 2.5 mg kg-1 in the water stress at grain filling stage increased grain yield up to 12 percent. Grain yield response to leaf feeding zinc sulphate in cultivar Pishtaz to Shiraz and Mahdavi cultivars was higher. According to grain yield in water stress at flowering stage to no water stress decreased 13 percent, but less than two rounds done of irrigation (468m3 ha-1) and water use efficiency significantly 60% increased. According to the results, the use of zinc at 2.5 mg kg-1 concentration in reducing water stress and using Pishtaz cultivar in water stress condition is recommended.