Impact of Foliar Application with Potassium, Calcium and Humic Acid on Growth, Fruit Yield and Quality of Muskmelon

The area under cultivation of muskmelon (cv. ‘Ananas’) is increasing in Iran. This cultivar is very sweet but has soft flesh and short shelf life. The present trial studied the interactive effects of foliarly applied with potassium (K); 0, 1 and 2 g l-1, calcium (Ca); 0 and 3 g l-1 and humic acid (HA); 0 and 1.5 g l-1 on growth parameters, fruit yield and quality. Compared with control treatment, K, Ca or HA increased relative water content (RWC), lateral branches, plant length, fruit length and diameter, flesh firmness at harvest and postharvest and peel thickness. Fruit number and brix were influenced by interactive effects of K and HA and flesh firmness and shelf life by K and Ca. Leaf number, final fruit yield and vitamin C, leaf and flesh K, Ca and Mg contents were increased by combinations of K (2 g l- 1), Ca (3 g l-1) and HA (1.5 g l-1) and therefore this treatment can be recommend to increased fruit yield and improve shelf life.