The Effects of Foliar Nutrient Applications on Fruit Split, Quality, and Yield and Leaf Nutrient Concentration of 'Wonderful' Pomegranate (Punica granatum L.)

Fruit split is the most important physiological disorder in pomegranate production, causing devastating crop losses worldwide. Foliar nutrient applications have been used experimentally to mitigate pomegranate fruit split but none have been conducted using the industry standard cultivar, Wonderful, and little is known about the effects of foliar nutrient applications on pomegranate. ‘Wonderful’ pomegranate trees at 2 commercial orchards were treated with foliar applications of ZnSO₄ (3000 mg∙L^-1, 4000 mg∙L^-1, or 5000 mg∙L^-1), MgSO₄ (1%, 2%, or 3%), KNO₃ (1%, 2%, or 3%), or deionized (DI) water (control). Fruit were analyzed for fruit split incidence, yield, total soluble solids (TSS), titratable acidity (TA), and mineral nutrient concentrations of leaves and fruit. Foliar applications of MgSO₄ and ZnSO₄ resulted in significantly lower fruit split incidence. Treatments had no significant effect on yield. Leaf N, K, S, Mn, and Zn were significantly affected by the treatments. TSS and TA were not affected significantly by treatments. Zn-treated trees had greater fruit Zn concentrations. The results suggest that foliar ZnSO₄ or MgSO₄ could be used to decrease fruit split incidence and increase nutritional content of ‘Wonderful’ pomegranate and any of the three tested foliar nutrients could be applied as a foliar fertilizer without negatively impacting fruit yield, internal quality, or mineral nutrient concentration.