The use of Promalin for manipulation of growth and cropping of young sweet cherry trees

Abstract

SummaryPromalin (6-benzyl amino purine plus gibberellins A4 + A7) increased spur and lateral shoot development when applied in paint to one-year-old wood of several sweet cherry cultivars. Although applications close to bud burst were slightly more effective, good responses were obtained at all timings during the 10-to 18-day period from bud swell to bud burst. Brown paint was a more effective carrier for Promalin than white paint. Localized increases in axillary development were possible as the response to Promalin occurred at and above, but not below, the treated area. Increased spur and lateral development caused by Promalin caused marked increases in flowering and cropping in subsequent seasons. Sprayed applications of Promalin after bud burst had no effect on axillary development and caused a reduction in return bloom. Despite variation between cultivars in response to painted applications, the use of Promalin offers new prospects for the management of young cherry trees.