Effect of Cluster Tipping on Yield, Cluster Composition and Quality of Ruby Seedless Grapevines

This study was carried out during the seasons of 2019 and 2020 on Ruby Seedless grapevine cultivar (Vitis venifera L.) to study the effect of cluster tipping on yield, clusters and berries quality. Tipping was conducted by removing the terminal part of the cluster; when the berry diameter reached to 3–4 mm, at 16, 18 or 20 cm. In this respect, the data showed clearly that cluster tipping should be done to modify the clusters characteristics into suitable shape and compactness. The obtained results indicated that cluster tipping at 16 or 18 cm were more effective for improving cluster composition, berry diameter and berry quality. Inspite of these treatments didn’t show any significant effect on yield/vine and per feddan, but they were more effective in increasing berry diameter and improving berry quality. Since, these treatments also increased both SSC/acid ratio, total sugar, anthocyanin and total phenols contents compared to the untreated ones. Therefore, these treatments can be recommended to improve the clusters and berries quality of Ruby ​​ seedless grape under Egyptian Delta region conditions.