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Since it began in 1966, the "progressive" system of tree improvement has been applied on 18 million acres of the Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) region. It departs markedly from earlier practice, needing no grafted seed orchard. Its flexibility, low cost, minimal needs for skilled personnel, and large genetic base attracted landowners who were reluctant to invest in grafted orchards, which were then beset with many problems. The early adoption of a second phase, involving crossing of all parent trees and establishment of seedling seed orchards, has accelerated the region toward widespread use of second-generation seed about 15 years earlier than originally anticipated.
Document Type: Journal Article
Director, Tree Improvement Laboratory, Industrial Forestry Association, Olympia, Washington
Publication date: February 1, 1979
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The Journal of Forestry is the most widely circulated scholarly forestry journal in the world. In print since 1902, the Journal has received several national awards for excellence. The mission of the Journal of Forestry is to advance the profession of forestry by keeping forest management professionals informed about significant developments and ideas in the many facets of forestry: economics, education and communication, entomology and pathology, fire, forest ecology, geospatial technologies, history, international forestry, measurements, policy, recreation, silviculture, social sciences, soils and hydrology, urban and community forestry, utilization and engineering, and wildlife management. The Journal is published bimonthly: January, March, May, July, September, and November.