Improving Yield and Bunches Quality of Sultana ‘H4 strain’ Grapevines

Abstract

This study was carried out during the seasons of 2021-2022 to study the effect of GA3 plus urea each alone or with trunk girdling and bunches tipping on yield and bunch quality of Sultana 'H4 strain' grapevines. The data reveal that spraying vines with GA3 plus urea at the beginning of (15-20%) flowering significantly reduced the number of berries per bunch and the compactness coefficient of the bunch than the control. Furthermore, sprayed vines with GA3 plus urea with both trunk girdling and bunches tipping significantly produced a higher bunch weight, berry weight, and size. Despite this, treated bunches with GA3 plus urea gave no clear effect of SSC/acid ratio in berry juice than the control but increased the values of total chlorophyll a and b content in berry skin. Whereas, when girdling the trunk and tipping the bunch produced a higher SSC/acid ratio in berry juice and total carotenoid content in berry skin than the control.

The Impact of Bud Load on Berry Quality, Yield, and Cluster Compactness in H4 Strain Grapevines

“…H4 strain grapevines are a strain of Thompson Seedless grape that was developed in Egypt in the early 2000s [1]. It has quickly become one of the most popular grape varieties in the world, due to its high yield and large clusters [2]. However, this strain produces clusters with high compactness and small berries, thus negatively affecting the cluster's quality during marketing [3].…”