Fruit Set of Eight Rabbiteye Blueberry ( Vaccinium AsheiReade) Cultivars in Response to Gibberellic Acid Application

Abstract

Eight rabbiteye blueberry ( Vaccinium asheiReade) cultivars were treated with gibberellic acid (GA ₃) under greenhouse conditions to determine the growth regulator's effectiveness in inducing parthenocarpic fruit set. Cultivars were ‘Baldwin’, ‘Bluebelle’, ‘Briteblue’, ‘Brightwell’, ‘Climax’, ‘Premier’, ‘Tifblue’, and ‘Woodard’. All cultivars had less than 10% fruit set in the absence of pollination or GA ₃. Fruit set of most cultivars was increased to 25% or more by a single application of 250 mg/L GA ₃applied at stage 5 to 6 of development (just before anthesis). A second application of GA ₃7 to 10 days later further increased fruit set of all cultivars except ‘Premier’ and ‘Woodard’. Fruit set in response to GA ₃ranged from 30% for ‘Briteblue’ to over 74% for ‘Brightwell’. Average weight of the parthendcarpic fruit ranged from 0.62 g/berry for ‘Briteblue’ to 1.08 g/berry for ‘Baldwin’. These results suggest that exogenously applied GA ₃can induce parthenocarpic fruit on many rabbiteye cultivars, although the resulting fruit set and size may vary.