Published August 1962. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Chilling requirements of 43 apple and 38 pear cultivars
were estimated over a 2 year period by cutting shoots in the
field at weekly intervals and forcing them in a warm
greenhouse for 4 weeks. For apples, the mean values ranged
from 490 Chill Units (CU) +- 1 for 'Dorsett...