Growth regulators applied on seedless grape 'Centennial Seedless'

The objective of present research was to evaluate the effects of increasing doses of forchlorfenuron associated, or not, to gibberellic acid on physical and chemical components of the 'Centennial Seedless' grapes. The treatments were gibberellic acid (GA(3)) (0 and 5mg L-1) associated with forchlorfenuron (0, 2, 4, 6, 8 and 10mg L-1). The variables were mass, width and length of bunches, berries and rachis, total soluble solids, pH, acidity and total ratio soluble solids/titratable acidity (SS/TA). The experiment was conducted in a vineyard located in the municipality of Sao Miguel Arcanjo, southwest of Sao Paulo State, and the regulators were applied at 15 days after full bloom by spraying the bunch. The interaction of the estimated dose of 5mg L-1 forchlorfenuron associated with GA(3), provided increases on the mass and width of the berries, and the estimated doses of 4 and 6.5mg L-1 of forchlorfenuron associated with GA(3) showed the lowest soluble solids and ratio SS/TA, respectively. The treatment with GA(3) resulted in gains in the diameter of the pedicels, mass of bunches, berries and rachis, and increasing the length and width of berries.