Effect of Potassium on Yield, Fruit Quality, and Chemical Composition of Greenhouse-Grown Galia Melon

ABSTRACT The effect of different potassium (K) rates on yield, fruit quality, and chemical composition of greenhouse-grown melon (Cucumis melo L., cv. Galia) was investigated. The experiment was carried out in a greenhouse similar to that used by farmers in the coastal Mediterranean region of Turkey. Control and three rates of potassium (0, 200, 400, 600 mg L−1) were applied to cv. Galia in a randomized complete block design with 3 replications. Leaf and fruit quality analyses were carried out and yield was determined. Different rates of potassium had no effect on yield. However, fruit number and fruit firmness were higher than the control at the 400 and 600 mg L−1 rates. Total soluble solids were higher than the control at the 600 mg L−1 rate. Average fruit weight was lower than the control at the 600 mg L−1 rate. Treatments did not affect nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), and zinc (Zn) contents of leaves, but leaf K content was higher than the control at all three rates. Iron (Fe) content was lower than the control at the 600 mg L−1 rate and manganese (Mn) content was lower at the 400 and 600 mg L−1rates. The data from our study indicate that 300 mg L−1 K in the root zone was sufficient for optimum yield of greenhouse-grown Galia melons. In terms of total yield, it is not necessary to apply higher rates of K. However, results show that it is possible to improve fruit quality by applying as much as 600 mg L−1 additional K to the plants without a reduction in yield.