Influence of CPPU (N- (2-Chloro-4-pyridinyl) -N-Phenylurea) on the berry size and fruit composition of several Vitis vinifera table grape cultivars

N-(2-Chloro-4-pyridinyl)-N-Phenylurea (CPPU), a synthetic cytokinin-like compound, was applied to clusters of Thompson Seedless, Flame Seedless, Ruby Seedless, and Crimson Seedless table grapes by dipping at concentrations of 0, 5, 10, and 20 mg/liter following fruit set to determine its effect on berry size and fruit composition. Treatments of 40 mg/liter GA3+IO mg/liter CPPU and 40 mg/liter GA3 alone, were included in the Thompson Seedless and Flame Seedless experiments to evaluate the synergistic effects of these materials on fruit quality. CPPU increased berry weight, length, and diameter of each cultivar and delayed fruit maturation by reducing soluble solids accumulation and anthocyanin in the colored cultivars. CPPU increased the force required to remove capstems from Thompson Seedless berries. CPPU+GA3 had a synergistic effect on the diameter of Flame Seedless berries as well as on the force required to remove capstems from Thompson Seedless berries.