EFFECT OF HEAT ON BUD-BREAK IN APPLE
Apple shoots of cultivars requiring low, intermediate and high chilling were excised from trees in the orchard in late November 1979, packed in damp peat moss and stored at 4°C. Shoot samples were removed from the peat at approximately monthly intervals through early April, held at 25°C in containers of water and observed over a 3 week period. Similar samples, chilled for various time periods, were placed in waterproof plastic bags, immersed in water and given a heat treatment of 39°C for 2 hours to test the ability of heat to overcome dormancy due to insufficient chilling. (Longer heating periods of 4 and 6 hours at 39° were tried without additional benefit). Observations were made for bud break as well as vigor of growth from brusting buds.
Huang, H. and Powell, Loyd E. (1981). EFFECT OF HEAT ON BUD-BREAK IN APPLE. Acta Hortic. 120, 252-252