International Journal of Horticulture, 2025, Vol.15, No.6, 290-298 http://hortherbpublisher.com/index.php/ijh 292 3 Effects of Leaf Removal on Table Grape Quality 3.1 Fruit appearance traits Removing the leaves significantly enhances several appearance traits of table grapes. Studies show that the process makes the berries and clusters heavier, longer, and wider, resulting in fruits that are larger and better appearing. There are also enhancements in rind color, which has increased lightness and chroma values, correlated with increased anthocyanin deposition due to greater exposure to sun. Better coloration is particularly important for commercial quality, since brighter color is often associated with quality in the consumer's mind. Although less frequently reported, increased skin rupture force and berry detachment force after leaf removal are signs of a tougher, more resistant peel, beneficial to appearance and handling at harvest and transportation (Tarricone et al., 2020; Yue et al., 2020b; Yao et al., 2024). 3.2 Physicochemical indicators Leaf removal exerts a beneficial effect on principal physicochemical indexes of grape quality. The general improvement in content of soluble solids (SSC, Brix), a measure of increased deposition of sugar in the berries. Sugar-acid ratio and pH rise, titratable acidity decreases, with a resulting sweeter and more palatable fruit. All these are caused through improved microclimate conditions around the clusters which enhance photosynthesis efficiency and transport of sugar to the berries. These improvements in acid and sugar equilibrium are very crucial for both fresh fruit intake and processing quality (Bakhsh et al., 2021; Lanati et al., 2021; VanderWeide et al., 2021; Wang et al., 2021). 3.3 Flavor-related compounds Leaf removal leads to extreme elevation in flavor volatiles, including aroma volatiles and phenol compounds. Greater sunlight initiates biosynthesis of anthocyanins, flavonols, and other phenolics that contribute to color depth, antioxidant activity, and complex flavor. Accumulation of aroma volatiles like monoterpenes and norisoprenoids is also increased, which improves sensory quality of the grapes. These changes have been linked with the upregulation of important genes in phenolic and aroma biosynthesis pathways, making defoliation a powerful mean to enhance both sensory and nutritional qualities of table grapes (Figure 1) (Alessandrini et al., 2018; Quartacci et al., 2022; Li et al., 2023). Figure 1 Phenolic compound loading profiles after grape leaf removal; LR-BF: Leaves removed 10 days before flowering, LR-AF: Leaves removed 35 days after flowering, LR-V: Leaves removed at veraison (Adopted from Li et al., 2023) 3.4 Postharvest storage ability and market value Berry firmness, skin rupture strength, and detachment force following leaf removal enhance the potential for postharvest storage since more firm berries are less likely to get damaged during transport and handling. Higher antioxidant activity and phenolics could further guarantee higher shelf life through lesser oxidative spoilage. All together, these quality advancements build market value for table grapes because they are delivering what
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