Effects of dormancy factors on the growth of vegetative buds of young apple trees

Abstract

Controlled temperature conditions were used to investigate the chilling requirements of potted 1-year-old apple trees cv. Jonathan. The rate of bud break, the number of buds growing and extension growth were increased by prior chilling.

Temperature effects over the range 2–10°C were greatest at the lower end of the range. Chilling early in the dormant period was less effective than later chilling, and interruption of chilling with periods of high temperature reduced subsequent growth.