Effect of Zinc Applications on the Productivity of Thompson Seedless Grapevines

Abstract

The most significant table grape cultivar in Egypt is the Thompson Seedless. Table grape production aims to improve grape quality attributes, primarily in response to market demand. A healthy grapevine's growth and development depend on zinc. To achieve optimal yield and berry quality, foliar treatment of zinc must be done while keeping an eye on suitable zinc levels. Twenty-eight uniform Thompson Seedless grapevines were used in the current experiment, which took place at the Fruit Section of the Faculty of Agriculture, Assiut University, at the Experimental Orchard throughout two consecutive seasons of 2021 and 2022. Seven treatments were conducted in four replicates (vines) and organized in a randomized complete block design. The treatments are: nano zinc oxide (1 and 2 ppm), zinc sulfate (100 and 200 ppm), chelated zinc (100 and 200 ppm), and control. Spraying was achieved when the new shoots reached 10-15 cm long, after fruit set, and one month later. The study's findings demonstrated that spraying the clusters with various forms and concentrations of zinc improved the Thompson Seedless grape cultivar's fruit quality and yield components in comparison to the control treatment. Following zinc sulfate at 100 ppm and chelated zinc at 100 ppm in that order, nano zinc oxide therapy at 2 ppm was likewise the most successful. Therefore, it might be suggested to spray the clusters with nano zinc at a concentration of 2 ppm or zinc sulfate at a concentration of 100 ppm for the best results.