The Effects of Some Growth Regulators on Peach Flower Bud Abscission

SummaryApplications of growth regulators to detached peach laterals in winter had variable effects on flower bud abscission. GA3 and GA4+7 increased bud abscission while IAA, BA and ABA inhibited abscission. Ethephon had a variable effect. Interactions were obtained between the compounds generally with IAA or GA playing the major role. GA had a peak of activity during a critical period in late winter indicating a variation in responsiveness. Variations in sensitivity to GA were obtained for different cultivars. Field applications of GA3, GA4+7, and ethephon to Elberta peach trees in winter, alone and in various combinations, promoted bud abscission.