Alleviation of Drought Stress Effects on Safflower Yield by Foliar Application of Zinc

Drought stress limits the oilseed crops productivity in semi-arid areas. To alleviate drought stress effects during seed-filling stage, the effect of foliar application of different Zn concentration (0, 0.6 and 1.2 kg ha(-1)) on five safflower genotypes was investigated in a 2-year (2015-2016 and 2016-2017) field experiments. The results showed that supplemental Zn (1.2 kg ha(-1)) significantly increased drought resistance by enhancement in proline (20%) and carbohydrate accumulation (4.3%), relative water content (2.4%) and chlorophyll content (3.8%) in all studied safflower genotypes. The induced improve in safflower's physiological traits achieved in the Zn supplemented treatment resulted in a significant increase in genotypes yield and its components. Moreover, Zn foliar application significantly reduced the drought adverse effect on oil yield and improved the unsaturated fatty acids content. Finally, Zn foliar application can represent an effective means to mitigate the adverse effects of drought stress on growth and the yield of safflower genotypes in water shortage condition.