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.

Keywords:

• Bacterial blight disease
• foliar sprays
• nutritional quality
• soil application
• Zn fertilization

Disclosure statement

This is to acknowledge no financial interest or benefit that has arisen from the direct application of this research.

Additional information

Funding

The authors express gratitude to the Indian Council of Agricultural Research (ICAR), New Delhi for the financial support of this research project.