Effect of different potassium levels on growth and quality in two melon cultivars and two growing-seasons.

摘要

Effects of potassium levels on fruit quality were evaluated in two Hami melon cultivars, 'Flavor No.4' and 'Xuelihong' in soilless medium culture under a plastic greenhouse. Four potassium (K) levels, K0 (control), K1 (insufficient), K2 (suitable), and K3 (excessive) in nutrient solution, which represent 0, 117, 234, and 351 mg/L of potassium, respectively, were applied. Fruit weight, size, soluble sugars concentrations, organic acids concentrations, and aromatic compounds were evaluated at fruit ripeness stage, in order to optimize potassium fertilizer application. Results revealed that at potassium level of 234-351 mg/L, the concentrations of total soluble solids, sucrose, K content, and volatile acetate components significantly increased in fruit flesh, which should improve the taste and aroma of melon. Favorable quality of melon in soilless culture was achieved when potassium level was adjusted to near 234 mg/L in nutrient solution.