Exogenous Gibberellic Acid (GA3) and Benzylaminopurine Enhance the Antioxidant Properties of Vaccinium corymbosum L. ‘Biloxi’ Fruits Without Affecting Yield

Vaccinium corymbosum L. ‘Biloxi’ is a cultivated blueberry variety valued for its rich content of phenolic compounds, which contribute to its strong antioxidant activity and recognized health benefits. There is little information on the effects of GA3 and BA on blueberry, especially when used in combination. This study aimed to evaluate whether GA3 and BA alter the yield and quality of V. corymbosum ‘Biloxi’ fruits. The experiment included 12 treatments consisting of GA3 (25, 50 and 100 mg L−1) and BA concentrations (50 and 100 mg L−1) alone and combined and a control. The following parameters were analyzed: yield (g) and number of fruits per plant, mass, diameter, pH, soluble solids (SS), titratable acidity (TA), soluble sugars, total phenols, flavonoids, anthocyanins and antioxidant activity. The results indicate that foliar GA3 and BA application improved the antioxidant capacity and biochemical composition of fruits, without negatively affecting production traits such as yield, fruit size or maturation period. The increases in antioxidant activity, phenol metabolites (total phenols, anthocyanins and flavonoids), soluble sugars, SS and SS/TA ratio were higher with the combination of GA3 and BA at 100 mg L−1. These results suggest that the combination of GA3 and BA is a promising approach to sustainably improve fruit quality in commercial blueberry cultivation, providing both economic and nutritional benefits.