Regulation of Douglas-fir Seedling Growth and Hardiness by Controlling Photoperiod
Abstract:Three experiments were conducted to determine how treatments with various photoperiods affect the growth, dormancy, and frost hardiness of Douglas-fir seedlings. In the first experiment, seedlings were exposed to an 8-h main photoperiod plus an 8-h period of supplemental light of varying intensities. Seedling growth was significantly greater than the control when the intensity of the supplemental light was 37 or more microwatts per square centimeter. In the second experiment, aimed at determining the effects of a wide variety of nighttime lighting regimes on seedling growth, a broad range of lighting treatments effectively extended both the magnitude and duration of seedling growth in the spring. The third experiment determined how various daylight periods and various intensities of light leakage affect the development of frost hardiness of seedlings in the late summer and early fall. Artificially shortening the daylight periods substantially increased the level of hardiness, but relatively low levels of light leakage greatly reduced this hardiness. These results indicate that a controlled photoperiod can be an effective tool for raising Douglas-fir seedlings in greenhouses in the Pacific Northwest when off-season planting or multiple cropping is desired. Forest Sci. 24:142-152.
Document Type: Journal Article
Affiliations: Professor of Forest Physiology, Forest Research Laboratory, School of Forestry, Oregon State University, Corvallis, Oregon 97331
Publication date: 1978-06-01
More about this publication?
- Forest Science is a peer-reviewed journal publishing fundamental and applied research that explores all aspects of natural and social sciences as they apply to the function and management of the forested ecosystems of the world. Topics include silviculture, forest management, biometrics, economics, entomology & pathology, fire & fuels management, forest ecology, genetics & tree improvement, geospatial technologies, harvesting & utilization, landscape ecology, operations research, forest policy, physiology, recreation, social sciences, soils & hydrology, and wildlife management.
Forest Science is published bimonthly in February, April, June, August, October, and December.
2015 Impact Factor: 1.702
Ranking: 16 of 66 in forestry
Average time from submission to first decision: 62.5 days*
June 1, 2016 to Feb. 28, 2017
Also published by SAF:
Journal of Forestry
Other SAF Publications
- Submit a Paper
- Membership Information
- Author Guidelines
- Ingenta Connect is not responsible for the content or availability of external websites