MELON CROP RESPONSE TO DIFFERENT LEVELS OF CALCIUM IN THE NUTRIENT SOLUTION

It is well known that calcium is an important nutrient to good growth of the whole plant. Experimental trial was carried out in Southern Spain (Almeria). Two nutrient solutions were used to fertigate melon plants (Cucumis melo L. cv. Alpes RZ) in coconut peat under glasshouse. Different proportions of Ca in the nutrient solutions were adjusted to maintain the cation-anion composition of the nutrient solution at 20 mmol_c L^-1. In this experiment two different rates of Ca were used: 9 and 7. mmol_c L^-1 Low levels of Ca in nutrient solution started at ripening period. The effects of different levels of Ca in nutrient solution on yield and quality of fruits, nutrient and water uptake and emission were measured. Yield and nitrate, phosphate, potassium and magnesium uptake were greater with nutrient solutions containing high levels of Ca. No significant differences were observed among the nutrient solutions studied for the quality parameters of fruits measured (soluble solids, firmness, dry weight, diameter).