Effect of gibberellic acid and para-chlorophenoxyacetic acid on the cropping and quality of Anab-e-Shahi grapes

Abstract

SummaryThree-year-old vines were selected at Ludhiana to study the effect of gibberellic acid (GA) and para-chlorophenoxyacetic acid (4-CPA) on bunch and berry weight, seedlessness and quality of Anab-e-Shahi grapes. Four concentrations each of GA (25, 50, 75, and 100 ppm.) and 4-CPA (5, 10, 15 and 20 ppm.) were applied by dipping the clusters at full-bloom. GA at 50 ppm. was highly effective in increasing the weight of berries and bunches. Among the 4-CPA treatments, 10 ppm. concentration was most effective in this regard. GA at 100 ppm. was more effective in inducing parthenocarpy in the berries than other concentrations of this chemical. The 4-CPA treatments had very little effect on the induction of parthenocarpy. The GA treatments resulted in increased acidity as compared with the control.