Peach Fruit Abscission as Influenced by Applied Gibberellin and Seed Development1

Postbloom application of gibberellin A 3 (GA 3 ) to open pollinated peach trees prevented seed development in some fruit, and also resulted in the persistence and maturation of both seeded and seedless fruit on the same trees. GA 3 temporarily promoted fruit growth and delayed abscission of both seeded and seedless fruit, but the final crop load was not altered. Both seeded and seedless fruit abscised from treated trees during physiological drop. The persisting seedless fruit, therefore, competed successfully with seeded fruit. Seedlessness was associated with smaller fruit size at maturity.