Effect of Salicylic Acid Foliar Application under Deficit Irrigation Conditions on Yield and Water Use Efficiency in Cucumber (Cucumis sativus cv. Kish F1)

Deficit irrigation is a method for water use management that water use efficiency increases by eliminating excess water. Application of crop growth regulators such as Salicylic Acid increase the resistance of crops under water stress. The purpose of the current study was to investigate the effect of Salicylic Acid foliar application under deficit irrigation conditions on yield of cucumber and water use efficiency. This study was contacted as factorial test based on randomized complete blocks in 3 treatments since June to November 2018 in The Research Filed of University of Zanjan on cucumber (cv. Kish F1). Experimental treatments were Salicylic Acid concentration in 3 levels (3.0, 1.5 and 0.0 mM) and irrigation water amount in 3 levels (100, 80 and 60% of crop water requirement). The control treatment was 100% crop water requirement and 0.0 mM Salicylic Acid. Based on the results, the foliar applicasion of 3.0 mM Salicylic Acid increased chlorophyll index, 32% at 100% crop water requirement and leaf area and relative water contants, 21% and 9.4% (respectivevly) at 80% crop water requirement as compared to the control treatment. Maximum means of fruits number per plant, total yield and water use efficiency were obtained at 3.0 mM salicylic acid foliar application (respectivevly 9.9, 34.1 ton/ha and 15.1 kg/m3) that they were 38.4%, 39.0% and 40.0% more than the one in treatment of 0.0 mM Salicylic Acid. Considering the results of current research, applicasion of 20% deficit irrigation and 3.0 mM Salicylic Acid as foliar application are suggested for cucumber in the region of Zanjan.