Effect of some Treatments on Reducing Sunburn in Red Globe Grapevines

Abstract

study the effect of some treatments shows that sunburned berries % was significantly reduced with spraying Kaolin at 4 %, Purshade at 4%, Screen Duo at 12 cm 3 /L, GA3 at 10 ppm+ 2 % Urea was investigated on the control of sunburn effects, berry temperature and yield quality of red globe grapevines grown under the Egyptian hot conditions during 2019 and 2020 seasons. The vines received three sprays of Kaolin, purshade and Screen Duo at (first-June, mid-June and mid-July), while GA3 and Urea were sprayed twice at two weeks after fruit setting and 30 days later for both seasons. Results showed that all treatments reduced berry temperature. The application of Screen Duo surpassed the application of Kaolin, Purshade and GA3 plus Urea in this respect as it was one of the most effective techniques in controlling. However, spraying in all treatments effectively reduced sunburned berries %, total acidity and improved yield quality, cluster weight, total soluble solids, anthocyanin and reducing sugar. Treatment with Screen Duo at 12 cm 3 /L+ GA3 at 10 ppm+ 2 % Urea gave the best results concerning Growth parameters, yield, cluster weight, cluster length, cluster width, sunburns and some physical and chemical properties of berries grapes. Control treatment gave the lowest value concerning all parameters in two seasons.