Abstract
Most species of the genus Eucalyptus that possess rapid growth and good form characteristics are too cold-sensitive for use in the southeastern coastal plain. In recent tests, however, several species, sources, and individuals within sources have demonstrated cold-hardiness combined with good form and growth. Such hardy eucalypts have potential for production of large volumes of hardwood fiber on sites accessible to wet-weather logging. Trees in the oldest plantings have survived over 150 nights of temperatures below freezing. The largest of these trees were 50 to 60 feet tall and 8 to 12 inches d.b.h. at age 4.5 years. The growth, survival, selected wood qualities, and future potential of eucalypts are discussed, based primarily on plantings at Bainbridge, Georgia. Four species (E. viminalis, E. nova-anglica, E. macarthurii, and E. camphora) have been selected as the most promising of those tested. Although other species such as E. rubida, E. dalrympleana, and E. nitens have grown more slowly, they do have good cold-hardiness and deserve further testing. Screening of additional species and seed sources continues. The best trees of the most hardy sources are being used as a genetic base for a tree improvement program.
The Success of Tree Breeding in the Southern US
