Residual Effects of Chemical Induction of Branching of Apple Trees in the Nursery on Their Performance after Transplanting

Abstract

One-year-old trees of three apple selections [NY73334-35 (A), NY75414-1 (B), and NY75413-30 (C)] from the Geneva Breeding Program were transplanted into an orchard. While at the nursery, the trees were treated with Promalin and Accel, by themselves or in combination, to promote lateral branch formation (feathering). After trees were transplanted, no growth regulators were applied to the trees. One year after transplanting, treated trees of B and C had produced more feathers than the controls. This was particularly pronounced with the very difficult-to-branch selection C. No differences between chemical treatments were found. Regardless of selection, each chemical treatment significantly influenced increase in total extension growth compared to the control and contributed to rapid build up of tree structure. There were no differences between the treatments in tree height, tree caliper, or the number of spurs.