Amin Abbasi

In order to study the effect of potassium on drought resistance and evaluate physiological reactions and grain yield of wheat cultivars under farmer field at chickpea rotation conditions in Hashtrood, a research-extension project as factorial based on randomized complete block design at three replications was conducted. Treatments including potassium-sulfate levels control, 75 and 150 kg/ha and three wheat cultivras Baran, Homa, Hashtrood. Potassium (K) treatments mixed with Nitrogen and Phosphorus according to designated ratio applied during plants sowing. With application of potassium sulfate, accumulation of K increased in plants and in Hashtrood it was more than Baran and Homa. Relative water content of Hashtrood was more than other varieties and this variety produced high chlorophyll and had more NDVI. By application of K-75 the contents of relative water and chlorophyll were increased. At this level of K, Hashtrood variety had more stomatal conductance than that of other varieties. With application of K-75 the value of Fv/Fm and PIabs were increased and thus the number of grain, grain weight and yield were also improved. Concluded application of K under severe water condition can improve wheat grain yield, considering the enough amount of potassium in dryland soils.