The Effect of Temperature and Bud Type on Rest Completion and the GDH°C Requirement for Budbreak in ‘Redhaven’ Peach

Abstract

Abstract Dormant ‘Redhaven’ peach [Prunus persica (L.) Batsch.] cuttings with flower, lateral vegetative, and terminal vegetative buds were exposed to either 7.2°, 3°, or 2°C for 600, 1340 or 2040 hr. Terminal vegetative (TV) buds had the shortest chilling requirement and showed less differential response to the various temperature levels than the other bud types. ‘Redhaven’ lateral vegetative (LV) and flower buds (FL) had similar chilling requirements. In general, 7.2° was more effective in releasing buds from rest than 3° or 2°. Prolonged chilling (2040 hr) decreased the growing degree hours (GDH°C) required for vegetative bud opening regardless of temperature. However, the GDH°C required for flower bud opening was decreased only by prolonged chilling at 7.2°C.