Effect of foliar‐applied gibberellins and soil‐applied paclobutrazol on reproductive and vegetative growth of ‘Braebum’ apple trees growing under a high‐density planting system

摘要

Abstract Five‐year‐old ‘Braeburn'/MM.106 (Malus domestica Borkh.) trees growing under a high‐density (10 000 trees/ha) planting system were treated with paclobutrazol (PBZ) as a soil drench at 250 mg(a.i.) per tree in August 1993. Gibberellin (GA), GA, or GA4, was sprayed on vegetative buds at 0, 10, or 100 μg per bud at three times between 22 November and 22 December 1992 (before PBZ treatment), or in 1993 (after PBZ treatment). Data on yield and yield components and vegetative growth were collected for 2 years. Time of GA application did not affect vegetative and reproductive growth components. The total shoot number, total shoot length, and total bud number were consistently reduced with PBZ application for 2 years of application. GA caused a decrease in shoot number across 2 years whereas total shoot length and total bud number were increased with GA treatment across 2 years. Fruit yield was decreased with PBZ application by 42 and 23% across 2 years in Trial A and by 27 and 12% across 2 years in tria...