Effect of zinc sulfate on growth and yield of wheat under soil zinc deficiency and drought stress

Drought stress is a major contributor to deacrese growth and yield of wheat that decline the absorption of micronutrients especially zinc from the soil. To assess application methods of zinc in wheat cultivar Homa under drought stress conditions, an experiment was carried out as split plot in a randomized complete block design with three replications in Faculty of Agriculture, University of Maragheh, Maragheh, Iran, in 2013. Two factors including drought stress (complete irrigation, drought stress at emergence of flage leaf and stress at emergence of awns) as main factor and zinc application methods (no-application, priming, soil application, spraying) as sub-factor were used. The results showed that total dry matter, harvest index, yield, spike weight, spike length, plant height, peduncle weight, peduncle length, canopy temperature, proline, chlorophyll and grain zinc content significantly affected by drought stress at 1% probability level. Zinc consumption method under drought stress was also significant on total dry matter, harvest index, yield, spike weight, peduncle length, canopy temperature, chlorophyll and grain zinc content at 1% probability level. The soil application of zinc at emergence of flage leaf stage increased total dry matter up to 4733.3 kg/ha (22%), grain yield up to 1732 kg/ha (11%) and grain zinc content up to 27.7 mg/kg (77%). The results of this research showed that soil application of zinc can be recommended for rainfed fields.