Stimulation of Lateral Bud Growth of Apple Trees by 6-Benzylamino Purine1

Abstract Orchard and greenhouse experiments were conducted to determine the influence of foliar applications of 6-benzylamino purine (BA) on branching of young apple trees. BA at 100 and 500 ppm, applied to actively growing shoots stimulated lateral bud growth on these shoots during the current season. The presence of fruit, termination of shoot growth, and the localization and non-persistence of BA reduced its effectiveness in breaking apical dominance. For optimum response to BA, multiple spray applications to actively growing shoots in a non-fruiting condition were required. Spray applications of BA failed to induce lateral bud growth on previous season’s wood.