Effects of plant growth regulators in seedless grape cv. BRS Clara, in tropical region

The purpose of this study was to evaluate the effect of the use of plant growth regulators, gibberellic acid and thidiazuron on berries size of BRS Clara in Tropical Region. The experiments were conducted in 2006 and 2007, in the Experimental Station of Tropical Viticulture in Jales, SP, northwestern region in the state of São Paulo. It was tested different concentrations of GA3 applied in isolation, combined with Crop set and thidiazuron, in single or sequential applications (2 and 4 times). The assessments were made during the ripening of the grapes, considering the masses of fresh bunch of rachis and berry, determined by analytical balance, the average length and the diameter of the berries, using caliper and the content of soluble solids (TSS), through manual refractometer. The experiments were conducted in a randomized complete block design, represented by a plant, with 15 repetitions in 2006 and 10 repetitions in the 2007. The data were subjected to analysis of variance and for the comparison of the average number of treatments it was used the Skott Nott test at the level of 5% probability. It was observed that the use of plant growth regulators promoted the growth of berries in BRS Clara, in all treatments differing of the control.