Gibberellins Stimulate Lateral Branch Development in Young Sweet Cherry Trees in the Orchard

Abstract

Previous studies showed that successful stimulation of lateral branch development from 1-year-old wood in young sweet cherry trees without reliance on pruning could be accomplished if suitable cytokinin- or cytokinin/gibberellic acid-containing products were applied to assure penetration into active tissues. The goal of the trials reported here was to determine the potential for stimulating lateral branching by applying gibberellic acid alone under similar conditions. Three commercially available products containing gibberellic acid were evaluated. Treatments included the isomers GA3, GA4, and GA4 combined with GA7. All gibberellic acid isomer/formulations were similar in their ability to stimulate branching from lateral buds on 1-year-old wood. In one trial, GA4+7 alone was nearly as effective as the cytokinin 6-benzyladenine. Combining the surfactant Pentra-bark with gibberellic acid resulted in successful branch induction without the need to apply gibberellic acid to scoring or nicking cuts in the bark.