Effect of foliar application of zinc on yield quality and quantity in wheat under water deficit

To investigate the effect of foliar application of zinc on yield production and seed quality of wheat under water deficit, an experiment was conducted as split factorial based on a randomized complete block design with three replications during 2009 and 2010 growing seasons. The main plot consisted of different water conditions (complete irrigation, halted irrigation after pollination, and after grain milk stage) and sub-plots comprised three wheat genotypes including Mahdavi, Shiraz and Pishtaz and three different concentrations of zinc including 0, 2.5 and 5 mg.kg-1. The results indicated that increasing stress intensity caused decreased grain yield, total dry matter and harvest index, but seed protein increased. Although, by increase water deficit, grain yield was reduced in all cultivars. Pishtaz showed the maximum grain yield (6107 kg/ha) when irrigation halted at pollination phase. However, all varieties, especially Mahdavi, produced higher yield at complete irrigation condition. Zinc sulfate application had a positive and significant effect on the most studied traits, so that application of 2.5 mg/kg zinc sulfate at complete irrigation treatment increased grain yield up to 27%. Besides, zinc concentration of seeds increased as zinc sulfate was applied.