Effect of K+ and Salicylic Acid on Broccoli (Brassica oleraceae var. Italica) Plants Grown Under Saline Water Irrigation

High salinity affects plant growth and productivity of most vegetable crops through osmotic effects which inhibition of water uptake by roots or specific ion effects and causes toxicity of salt ions, as well as changes in soil physical and chemical properties causing a decrease in the growth of the roots and plants. This research conducted to improve the agricultural practices of broccoli production by using the K+ and salicylic acid (SA); which will contribute to overcome the deleterious effect of salinity stress. The results of this study showed that broccoli plants grown under saline water that receiving K+ at concentration 1000 mg l-1 as foliar application were recorded minimum the deleterious impacts of salinity stress and achieved maximum plant height, number of leaves and branches, leaf area per plant, the main, secondary and total curd yield (t ha-1) and water use efficiency (WUE) over control treatment. Furthermore, the curd diameter (of main and secondary), curd weight (of main, secondary and plant) dry matter percentage of the curds and the leaf and curd mineral contents (N, P and K%) were improved with foliar application of K up to 1000 mg l-1. Moreover, the vegetative growth, cruds yield and its quality, WUE and leaf and crud mineral contents of broccoli plants irrigated with saline water increased significantly and successively as the SA concentration was increased up to 200 mg l-1. The combined foliar application of 1000 mg l-1 K+ with salicylic acid at 200 mg l-1 as a dernch and foliar application is the most efficient combination treatment, which gave the best results to alleviate the deleterious impact of salinity stress on the vegetative growth, curd yield and its quality characters, leaf and curds chemical contents of broccoli plants irrigated with saline water.