Abstract
In a series of experiments, gibberellic acid (GA 3 ) was applied to rabbiteye blueberries ( Vaccinium ashei Reade) under field and greenhouse conditions to determine if fruit set could be improved following physical or freeze injury to flowers. In field experiments, physically damaged flowers (i.e., corollas and styles removed, styles only removed, or ovaries lanced) of `Climax' and `Tifblue' treated with GA 3 (4% ProGib at 250 mg·liter –1 ) set substantially more fruit than nontreated, damaged flowers. Under green-house conditions, GA 3 applied postfreeze to `Tifblue' and `Brightwell' resulted in increased fruit set compared to unsprayed control plants of the same cultivars. Freeze-damaged plants had substantially reduced fruit set overall but to a much lesser extent for GA 3 -treated plants than for those not treated with GA 3 . Individual fruit weight was reduced by GA 3 applications, as was berry seediness. Results from these greenhouse and field trials suggest that GA 3 can be used to salvage a blueberry crop following a moderate freeze during bloom.