Gibberellin Effects on Photoperiodcontrolled Growth of Weigela

Abstract

Weigela, a woody ornamental plant, produces uninterrupted vegetative extension when grown at photoperiods in excess of 14 hr., whereas at shorter photoperiods (<14 hr.) vegetative growth ceases, and the plant enters a dormant condition^1–3. This communication describes the replacement of the photoperiodic requirement for the vegetative development of Weigela with gibberellin applied to plants grown under a short photoperiod, and the acceleration of growth under a long photoperiod.