Influence of Salicylic Acid on Cucumber Plants under Different Irrigation Levels

Abstract

In order to evaluate the effect of foliar application by salicylic acid (SA) on vegetative growth and yield responses in cucumber plants under different irrigation levels. Two field experiments were performed at a private farm in Dekernes, Dakahlia governorate, Egypt, in summer seasons of 2017 and 2018, to investigate the impact of four foliar application rates of salicylic acid (0.0, 0.15, 0.30 and 0.45 g/l) and three irrigation levels (1200, 900 and 600 m3/fed.) on growth and yield of cucumber cv. Gabbar. Water shortage stress significantly reduced vegetative growth (main stem length, branches number, foliage fresh weight, leaves number and leaves area per plant and yield components; fruits weight and numbers per plant, Vit. C, TSS and total yield (ton/fed.). On contrary, foliar application of SA significantly improved these parameters under water shortage stress conditions. However, the lowest used water irrigation quantity increased leaf and fruits dry matter percentage, sex ratio and water use efficiency. On the other hand, water shortage stress significantly reduced leaf pigments (chlorophyll a, b and carotenoid) as compared to the highest rate (1200 m3) and these were further increased by using SA. Salicylic acid at a concentration of 0.30 g/l gave the highest fruits yield and its components. As well as, 1200 m3/fed and 0.3 g/l salicylic acid treatments were recorded the highest values for most effective mentioned criteria.