Effect of Ethephon and GA3 on Time of Flowering in Peach

Abstract

Ethephon at 200 ppm applied to ‘Cresthaven’ peach trees [Prunus persica (L.) Batsch] in October delayed flowering by 7 days in the first year of this study, but only by 3 days in the 2nd year. Flower bud survival was reduced in both years by this treatment, although the percentage of fruit set increased. The differences observed in the effectiveness of ethephon in delaying bloom may be due to differences in spring temperatures during bud expansion. High temperatures during the period of bud expansion tended to accelerate bud development, minimizing the effect of treatment, whereas low temperatures during this period tended to accentuate treatment effects. GA3 applied in October delayed leaf senescence and abscission, but did not delay flowering.