Abstract
Gibberellic acid (GA3), a plant growth regulator is commonly used for berry enlargement in grapes. Flame seedless grapes vines,
grown at NARC, Islamabad, were sprayed at bloom and fruit set (just after berry shatter) with GA3, at the concentration of 15ppm,
20pp and 25ppm. For each treatment, GA3 was applied twice with the first spray at 80% blooming and second spray a week later just
at fruit set. Water was sprayed to serve as a control. Average cluster and berry weight of sprayed vines increased significantly over the
non-sprayed vines and the largest cluster weight depicted as fruit yield per vine (344.22g) was found in the treatment with highest
concentration of GA3 (25ppm). Maximum berry weight, width, length and TSS i.e. 2.82g, 1.79cm, 1.85cm and 19.00% respectively,
were recorded at 25ppm. Statistical differences were observed for cluster weight, berry weight, berry width, length and TSS with GA3
at 15ppm and 20ppm. Based on this research, 25ppm of GA3 is recommended for spray on the flame seedless grape cultivar for
obtaining higher yield and better quality.
