Gibberellic Acid: A Management Tool for Increasing Yield of Rabbiteye Blueberry

Field and growth chamber experiments, as well as grower trials, were conducted to determine the effects of GA₃ sprays on fruit set and yield of rabbiteye blueberry (Vaccinium ashei Reade) in north Florida and south Georgia. Multiple GA₃ sprays at different stages during bloom increased fruit set and yield in field experiments in Florida and in grower trials in Georgia. However, GA₃-treated fruit were smaller and matured later than untreated fruit. Similarly, GA₃ application to non-pollinated flowers under controlled environmental conditions increased percent fruit set, decreased average fruit weight, and increased fruit development period when compared to hand-pollinated fruit. High night temperature (21°C) reduced fruit set and average fruit weight compared to 10°C night temperature for both GA₃-treated and hand-pollinated fruit. Overall, results indicate that use of GA₃ under conditions of low natural fruit set in the field may significantly increase yield, although much of the yield increase would be comprised of later maturing, smaller fruit. [Article copies available from The Haworth Document Delivery Service: 1-800-342-9678.]