Roberto Soto-Ortiz, Jeffrey Silvertooth, and Abraham Galadima. Univ of Arizona-Soil, Water & Env Science Dept, PO Box 210038, Shantz 429 Bldg #38, Tucson, AZ 85721
Information regarding optimum fertilization and nutrient management for irrigated melons in AZ and the desert Southwest of the U.S.A. is very limited. There is very little information available concerning nutrient requirements for melons in terms of uptake patterns, distribution within the plant, and heat units after planting date (HUAP) relationships. In this study 19 field experiments involving 10 melon varieties were conducted from 2003 through 2005 at five locations in Arizona. Nutrient uptake (N, P, K, Ca, Fe, B, and Zn) was determined at four distinct stages of development (pre-bloom, early fruit set, early netting, and physiological maturity). Data were analyzed statistically as a repeated measures design and nutrient uptake models were developed for each plant nutrient among all experimental sites. In general, nutrient uptake patterns of melons developed with a high degree of consistency as function of HUAP among all varieties and all sites. A period of high nutrient demand at (~400 – 850 HUAP) was detected for several nutrients, which corresponds with the early fruit set period. Therefore, based on these results, fertilizer inputs prior to this stage of growth will be critical in developing nutrient management programs for optimum yield, quality, and efficiency.