Effect of Dormex, CPPU and GA3 on berry growth and ripening of Pusa Seedless cultivar of grape.

Abstract: The effects of Dormex (40% aqueous hydrogen cyanamide), CPPU [forchlorfenuron], and gibberellic acid (GA3) on the fruit growth and ripening of grape cv. Pusa Seedless were studied in New Delhi, India, in 1998. The treatments consisted of spraying plants with 1.5% Dormex solution immediately after pruning (T1); T1 + dipping of bunches in 0.15% CPPU solution after fruit set (T2); and T2 + dipping of bunches in 45 ppm GA3 at the full bloom stage. Fruits were sampled at weekly intervals from two weeks after flowering until harvest. Plants treated with Dormex exhibited earlier bud break (by 30 days), flowering (by 12 days), and ripening (by 7 days) than the control. Unlike in the control and Dormex-treated plants, fruit fresh weight in plants under T2 and T3 increased continuously until harvest. Ripening date did not significantly vary between the control plants and plants under T2 and T3; however, fruit growth period was longer in plants under T2 and T3 than in the control. Treated plants had higher fruit fresh w