Use of Enriched Fertilization to Overcome Nutritional Deficiency in Grafted Melons

Melon plants grafted on Cucurbita rootstock can suffer from nutritional deficiencies due to reduced absorption and translocation of minerals to the foliage. Melon (Cucumis melo L.) cultivar 6023 was grafted onto two interspecific rootstocks (C. maxima x C. moschata)-TZ 148 and 53009. Nongrafted melons were used as controls. A fertilization experiment was conducted in a greenhouse in southern Israel. Two fertigation regimes were used: standard and enriched to Mg (150 mg/L), Mn (7.5 mg/L) and Zn (0.75 mg/L) to increase the concentrations of the lacking elements. Total contents of macro- and micronutrients (N, P, K, Ca, Mg, Na, Cl, Fe, Mn, Zn, and B) were determined in leaves of control and grafted plants. The rootstocks increased K and decreased Ca, Mg, Na, Mn and B in the leaf tissue relative to nongrafted plants. The enriched fertilizer significantly increased Mn and Zn contents in the leaf tissue, and decreased B concentration. Concentrations of N, P, Cl, and Fe were not affected by the enriched fertilizer. There were almost no deficiency symptoms in grafted plants supplied with the enriched fertilizer.