Zinc nutrition improves fruit yield, quality, and reduces bacterial blight disease severity in pomegranate (Punica granatum L.)

Abstract

The study was designed to identify the most effective way of fertilizing Zn for improved productivity and quality of pomegranate cv. Bhagwa on calcareous soil. Fertilization methods included foliar sprays of ZnSO4, Zn-EDTA, and amino acid chelated Zn; irrigation applied ZnSO4 and Zn chelate (Zn-EDTA); soil application of ZnSO4 (@ 12.5 and 25.0 g tree−1) and were evaluated on full grown pomegranate orchard for 2 years. All the Zn treatments of foliar and irrigation-applied methods were effective in raising the leaf Zn concentration above the recommended adequate level (>15.98 mg kg−1). Higher number of hermaphrodite flowers was observed with foliar sprays of ZnSO4, amino acid chelated Zn, irrigation applied Zn-chelate, and soil application of ZnSO4 @ 25 g Zn tree−1. Various Zn application methods except irrigation-applied ZnSO4 increased fruit yield by 4.33–23.63%. Some of the Zn treatments viz. foliar sprays of ZnSO4, amino acid chelated Zn and irrigation-applied Zn-chelate caused substantial improvement in fruit quality attributes such as fruit size, aril and juice percent, biochemical attributes like juice acidity (by 8.33–13.89%), anthocyanin, ascorbic acid concentration, and enrichment of Zn in the edible part of the fruit. Interestingly, sprays of ZnSO4 also enriched Fe, Mn, and Cu in the arils. While some of the Zn treatments viz. foliar spray of ZnSO4, irrigation-applied Zn-chelate and soil application of ZnSO4 could reduce bacterial blight disease incidence by 19.29–25.97% and severity by 22.18–47.36%. Hence, foliar sprays of ZnSO4 are recommended for enhancement of fruit yield as well as quality in pomegranate.