617 Effects of Nitrogen, Potassium, and Irrigation on Postharvest Pitting of White Grapefruit

in HortScience
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  • 1 Florida Department of Citrus, CREC, 700 Experiment Station Road, Lake Alfred, FL 33850
  • | 2 University of Florida, CREC, 700 Experiment Station Road, Lake Alfred, FL 33850
  • | 3 University of Florida, IRREC, 2199 S. Rock Road, Fort Pierce, FL 34945

Effects of N, K, and water relation on the incidence and severity of postharvest pitting in white grapefruit were evaluated in two field experiments. In the first experiment, a factorial combination of 3 N (56, 168, and 336 kg·ha–1) and 3 K (52, 156, and 312 kg·ha–1) rates were used with three broadcast applications per year. In the second experiment, there were two irrigation regimes (at 30% and 60% depletion of available soil moisture, ASM, content) with three subtreatments of variable N and K rates (Kg·ha–1) at 56: 52; 112: 104, and 336: 312 kg·ha–1. The fruit were harvested three times each season, waxed with shellac wax, and stored at 70°F for evaluation of pitting. The pitting incidence was lower at the optimal N and K rates than that at the low or high rates. The irrigation at 30% ASM significantly reduced pitting incidence. The higher incidence of pitting was found in an area in the grove with higher water table. This study suggested that effects of water may play an important role on peel physiology and pitting.