RT Journal Article SR Electronic T1 Effect of 2-Chloroethylphosphonic Acid (Ethephon) on the Endogenous Levels of Gibberellin-Like Substances and Abscisic Acid in Buds and Developing Shoots of Three Grape Varieties JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 164 OP 167 DO 10.5344/ajev.1982.33.3.164 VO 33 IS 3 A1 Franco Mannini A1 Kay Ryugo YR 1982 UL http://www.ajevonline.org/content/33/3/164.abstract AB Dormant buds and young developing shoots from grapevines sprayed with ethephon in the fall to hasten defoliation were analyzed for gibberellin-like substances and free and bound abscisic acid (ABA). The treatments which resulted in delayed budbreak had no effect on free gibberellic acid (GA) level but enhanced ABA and bound-GA syntheses. The presence of ABA in bud extracts, which depressed α-amylase activity in the barley endosperm bioassay, was confirmed by gas chromatography.