EFFECTS OF CHILLING AND HEAT ON GROWTH OF GINKGO BILOBA L.

The effects of chilling on growth and development of ginkgo biloba (Ginkgo biloba L.) seedlings were evaluated in a study initiated on February 1, 1999, and terminated on September 10, 2002. Thirteen levels of chilling were applied to trees in increments of 100 hours, with 12 replications per treatment. Increased chilling led to a decreased heat unit requirement, resulting in greater overall growth and development. Within the group of trees receiving the same treatment for three consecutive years, trees receiving 1,100 chill hours had greater caliper, terminal shoot extension, and total plant height. In this same group, greater limb structure was obtained from trees receiving 600 chill hours. Chilling was a determinate factor in growth and development.