EFFECT OF GIBBERELLIC ACID ON THE YIELD OF PARTENOCARPIC AND STENOSPERMOCARPIC GRAPE CULTIVARS

Abstract

The aim of this study was to determine the effects of gibberellic acid (GA₃) on yield of table grape cultivars at the relationships structure-function: Leaf ÷ Yield. The GA₃ was applied in “Flora”, “Talisman” and “Kishmish luchistii” grapevine cultivars by spraying clusters 4-6 days after full bloom. The GA₃ treatments were at the 0 (control); 20; 40; 50; 60; 80; 100 ppm. The application GA₃ changes of grape yield, bunch compactness parameter, and quality of grape berries. Permissible values of ratio Leaf ÷ Yield will be equal to 0.8 m² for ripeness under normal conditions of 1 kg of table grapes. In “Flora”, “Talisman” and “Kishmish luchistii” cultivars at the cordon trained system with a density of 2222 vines ÷ ha (3×1.5 m), the increase of the yields and quality of table grape occurred after the use of 40 ppm of GA₃ with one application after full bloom and norms 8-10 clusters per vine.