Optimizing Irrigation Rates and Antioxidant Foliar Spray Effects on Growth, Yield, and Fruit Quality of Manfalouty Pomegranate Trees

This study aims to identify the most effective irrigation rates for Manfalouty pomegranate trees to enhance their growth, yield, bioactive compound content, and fruit quality. Additionally, the research evaluates the effects of foliar spray applications of glycine, ascorbic acid, and riboflavin on the physiological responses of the trees. Morphological, physiological impacts, and fruit quality treatments were analyzed using Pearson correlation and cluster analysis. As irrigation levels were reduced up to 60%, all vegetative characters demonstrated a significant drop. Glycine treatment enhanced yielding shoot lengths, leaf area, and leaf number. Among the key findings was that there were no appreciable variations between 100% ETc and 80% ETc with riboflavin or glycine spraying for leaves total chlorophyll. Leaves treated with glycine, ascorbic acid, and riboflavin spraying had higher levels of total antioxidants, total phenols, and total flavonoids, while glycine gives the highest results and enhanced the antioxidant system of pomegranate leaves. Reducing irrigation from 100% to 60% ETc in both seasons, respectively, resulted in a progressive decrease in yield (ton/fed.), and fruit creaking (%); this effect was overcome using the glycine foliar spraying. The results also demonstrated that all spray treatments reduced the cracking rate, with the glycine spray treatment being the most effective in this respect that enhanced also fruit length, fruit diameter, fruit weight, and arils weight %, total soluble solids, total sugar, anthocyanin, vitamin C, and the antioxidant contents. The findings provide valuable insights for sustainable pomegranate cultivation practices that maximize productivity and quality while maintaining plant health using low irrigation and glycine as foliar sprayer.