Relationship of Endogenous Flower Bud Abscisic Acid to Peach Chilling Requirements, Bloom Dates, and Applied Gibberellic Acid1

Abstract

Abstract Concentrations of total abscisic acid (ABA) in flower buds from 7 clones of peach (Prunus persica (L.) Batsch) were measured on 4 sampling dates and compared with chilling requirements (CR) of these clones. In December the correlation coefficient between ABA content and CR was r = 0.89. ABA concentration increased with tree vigor. Fall-applied gibberellic acid (GA3) decreased ABA concentration in flower buds in December and delayed bloom the following spring.