Exogenous Pre-harvest Application of Abscisic and Jasmonic Acids Improves Fruit Quality by Enhancing Sugar Synthesis and Reducing Acidity in Pomegranate (Punica granatum L. cv. Wonderful)

Abstract

One of the major issues with pomegranate production in arid and semi-arid climate is the white arils of fruit. The known plant regulators abscisic and jasmonic acids play a variety of roles in plant growth and the reduction of abiotic stresses. However, little is known about their application to improve the quality of pomegranate fruit, particularly white arils, in semi-arid environments. Herein, the experiments, in this study, were performed in two consecutive seasons 2020 and 2021 on 10-year-old Wonderful pomegranate trees to spotlight the improvement of the aril coloration and fruit quality by spraying with abscisic and jasmonic acids under semi-arid climatic conditions. Fifteen Wonderful pomegranate trees were subjected to five treatments (three replications for each). The tested treatments included abscisic acid (ABA) at the concentrations of 600 and 800 µg−1 mL, jasmonic acid (JA) at the concentrations of 10 and 15 Mm, and the control treatment (distilled water). The physical and chemical characteristics of the fruit quality of Wonderful pomegranate improved significantly when the trees were treated with abscisic or jasmonic acids. The foliar addition of ABA at 600 and 800 µg−1 mL increased the anthocyanin index by 96.74 and 114.75%, respectively, in the first year and by 49.48 and 67.62% in the second year, in comparison with the control. The foliar addition of ABA at 800 µg−1 mL was more effective than jasmonic acid in enhancing most of the chemical fruit properties, especially the anthocyanin index. The high level of ABA (800 µg−1 mL) gave the minimum fruit acidity and the highest fruit quality. Abscisic acid induces the fruit acidity and enhances the aril coloration in Wonderful pomegranate. In semi-arid conditions, it is recommended to spray the Wonderful pomegranate trees with abscisic acid at 800 µg−1 mL to improve the fruit quality and to increase the aril coloration.