Bloom (20 mg/L) and various postbloom (40 to 100 mg/L) applications of gibberellic acid (GA) ± basal leaf removal (BLR) were imposed on Sovereign Coronation vines over a three-year period. GA increased yield in one of three years and berry weight in all three years, while vestigial seed development decreased in two of three years as a linear function of the concentration of GA applied. Brix was reduced linearly with increasing GA in two of three years, pH was generally unaffected, but titratable acidity decreased with increasing GA. Color intensity and anthocyanins increased relative to GA in 2002 only. Methyl anthranilate increased relative to GA in one season while total volatile esters also increased with increasing GA. Treatments involving 40 mg/L GA led to higher fruity and labrusca flavor, sweetness, persistence of flavor, and overall impression, as well as lower acidity and bitterness. Basal leaf removal delayed berry maturity slightly but increased light penetration into the canopy. Berries from non-GA-sprayed control treatments ± BLR were separated into several maturity categories (based on berry Brix) by sucrose buoyant density gradients and were thereafter subjected to sensory evaluation. Increased berry maturity was associated with decreased berry weight and titratable acidity, and increased color intensity, anthocyanins, phenols, methyl anthranilate, and total volatile esters. Principal component analysis coupled with discriminant analysis suggested that soluble solids ≥17 Brix was associated with sweetness, fruity, labrusca, and overall impression.
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