Yield and fruit quality of melon plants grown under saline conditions in relation to phosphate and calcium nutrition

Melon plants were grown hydroponically in a greenhouse to investigate the i nteraction of phosphorus and Ca2+ under saline conditions on vegetative bio mass production, yield and fruit quality. Two levels of Ca2+ (2 and 8 mM) w ere combined factorially with two levels of phosphate (0.2 and 1 mM) under two regimens of NaCl salinity (10 and 80 mM). The increase of Ca2+ concentr ation in the nutrient solution under saline conditions improved to the same extent vegetative growth and fruit yield. Parameters of fruit quality were affected by salinity, phosphorus and Ca2+ nutrition. Salinity increased fr uit quality by increasing firmness, total sugars and total soluble solids ( TSS). High Ca2+ treatment increased sucrose, fructose and glucose, this eff ect being greater under low salinity conditions than under high. In the two saline treatments, the highest concentration of sucrose in flesh was found at 0.2 mM of phosphate in the nutrient solution.