Influences of Potassium Foliar Fertilization and Irrigation by Diluted Seawater on Growth and Some Chemical Constituents of Cotton

A pot experiment was conducted in the greenhouse of the NRC, Dokki, Giza, Egypt aimed to evaluate the influences of K foliar fertilization [one or two sprayings in the rate of 200 ppm potassium chloride more than the distilled water (as a control)] and irrigation by (DSW) diluted seawater (with EC 3.91 and 7.82 dS/m more than the fresh water 0.30 dS/m as a control) on growth and some chemical constituents of cotton plants. Contentious decreases were detected in plant height, area of green leaves, number of bolls, stem, bolls and top fresh weight (FW) and dry weights (DW) exerted by the increasing in salt concentration in the DSW. However, the response of number, FW and DW of green leaves to both salt levels was approximately equal. Significant effects were shown in area of green leaves, FW and DW of bolls and top FW and DW/plant. The increments in bolls and stem numbers, FW and DW of bolls, top FW and DW increased by one spraying of K fertilizer and depressions were induced as a result of application K fertilizer twice. The differences in plant height, number of leaves and stem and leaves FW as well as DW were not significance. In plants irrigated by fresh water (0.38dS/m) area of green leaves increased by 8.46 and 46.25 %, FW increased by 25.55 % and decreased by 22.54 % and bolls DW by 22.54 and 49.62 % when plants receive one or two sprayings of potassium chloride, respectively. Effect of salinity and potassium spraying on some chemical constituents (Chlorophyll and some macronutrients) were also evaluated. Nitrogen, phosphorus and potassium concentrations in cotton leaves increased as the salt concentration increased in irrigation water. Foliar application increased the concentration as well as content of N, P and K in leaves.