The effects of different GA3 concentrations and application times on fruit set, fruit development period, and fruit quality in rabbiteye blueberry (Vaccinium ashei Reade) were studied. Flower clusters were sprayed with 100 or 250 ppm GA3 at 90% full bloom and again 7 days later, or with 125 ppm GA3 at 90% full bloom and again 7, 21, and 42 days later, under greenhouse conditions. Fruit set was monitored every 10 days and fruit weight, fruit development period, soluble solids, and titratable acidity were measured at harvest.
Fruit set in GA3 treatments averaged 69 to 76% compared to an average of 43% for the pollinated control. Weight of GA3 treated berries averaged 1.2, g while that of pollinated berries averaged 2.0 g. However, calculated total yield was greater for the GA3 treatments compared to the pollinated control, averaging 244 and 206 g/treatment, respectively. GA3 increased the fruit development period by 2 to 11 days, depending on the treatment. Soluble solids and titratable acidity were not affected by any treatment.