The effect of Zn and K application on some physiological traits and yield of wheat (Triticum aestivum L.) under drought stress

To investigate the effect of zinc and potassium application on some morphological traits and yield of wheat (Triticum aestivum L.) under drought stress, a split-factorial layout based on a randomized complete block design (RCBD) with three replicates were carried out at the experimental farm of the Research, Education and Extension Center of Agriculture and Natural Resources of Hamadan during 2017-2018. The main plot included irrigation levels (normal and water stress) and the subplot included two factors of foliar application of potassium (K) and zinc (Zn) fertilizers. Potassium fertilizer from K2O source (40%) including 2 L/ha at three levels; I) without fertilizer (control sample), II) leaf spray at the beginning of booting, III) leaf spray after pollination, and zinc fertilizer from water-soluble zinc source (10%) including four liters per ha in three levels; I) without fertilizer (control sample), II) leaf spray at the beginning of booting, III) leaf spray was used after pollination. The results of the analysis of variance showed a significant difference between treatments in all studied traits. Significant differences in all of the traits were observed under stress and normal irrigation. Co-application of potassium and zinc fertilizers compared to the control increased grain yield (4.5%) and RWC (5.8%) evaluated morphological indices under stress conditions.To investigat