The effect of talc, kaolin, and zinc oxide on heat stress in pomegranate cv. Malas saveh

Sunburn is one of the significant problems in pomegranate growing, which reduces fruit yield and quality. This study was conducted to evaluate the impact of the application of antiperspirants on the quality and biochemical properties of pomegranate fruits. The experiment was carried out as a completely randomized design with nine treatments and three replications. Treatments include 2% solution talc (T), zinc oxide (ZnO), kaolin (K), zinc oxide+talc (ZnT), talc+kaolin (TK), zinc oxide+kaolin (ZnT), zinc oxide+talc+kaolin (ZnTK), shading with 50% light passing and control (sprayed with water). The highest edible fruit was measured in the ZnO treatment. The maximum and minimum thickness of fruit peel was measured in the control and shading treatments, respectively. ZnO treatment reduced the thickness of the fruit peel by 30.8% compared to the control. The lowest temperature of fruit and leaf was measured in shading and ZnT treatment, respectively. The control treatment produced the lowest Fv/Fm and leaf area, (LA), and the shading treatment resulted the highest Fv/Fm, LA and chlorophyll. ZnO treatment increased Fv/Fm and LA by 11.95% and 15.55%, respectively, compared to the control. The highest anthocyanin and phenol of juice were recorded in shading treatment. The highest fruit peel phenol and the lowest fruit peel lipoxygenase activity were measured in the ZnTK treatment. The results indicated that the ZnO treatment is a suitable treatment due to the decrease in the percentage of fruit peel and the increase in the Fv/Fm and the decrease in the activity of the lipoxygenase enzyme.