Application of a PhotoThermal model for container-grown conifer seedling production

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Steven Grossnickle


This study applied a total energy approach to model seedling growth for container-grown loblolly pine (Pinus taeda L.). Seedlings were grown in three container stocktypes representing a range of cavity volume and density patterns. These seedlings were grown under both controlled greenhouse and outside compound environmental conditions under well-defined cultural conditions. Models for temperature and light ranges were created from work on the ecophysiological performance and morphological development of loblolly pine to these atmospheric conditions. A PhotoThermal data set was created by generating hourly averages of these two environmental variables during the growing season. Light and temperature data were integrated, each weighted equally, into PhotoThermal hours (PTH) to assess the crop growth response. Loblolly pine seedling growth in both the greenhouse and outside compound was directly related to PTH. Seedling growth was also related to the container type with the largest cavity volume and lowest cavity density having the greatest growth per PTH. Application of the PhotoThermal model is discussed for growing seedlings in an operational program having multiple production steps, delivery dates and nursery locations.


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How to Cite
Grossnickle, Steven. “Application of a PhotoThermal Model for Container-Grown Conifer Seedling Production”. REFORESTA, no. 8 (December 31, 2019): 1-16. Accessed July 3, 2020.
Author Biography

Steven Grossnickle, NurseryToForest Solutions

Steve has conducted work in the plant sciences/forestry field for over thirty years within university and industry programs throughout the U.S. and Canada, regarding ecological and physiological processes of plants in operational nurseries and forested areas. These research programs focused on areas of genetic diversity, and the performance and development of plants in relation to nursery practices, silvicultural operations and ecosystem restoration. Steve has collaborated with the nursery industry, both forestry and horticulture, and the forest industry to address operational issues.Steve has earned an international reputation as a scientist and practitioner addressing basic biological and ecological processes of plants within research, extension and educational programs. These programs were conducted with external partners in universities, government, and the nursery and forest industries. Steve has published a book (Titled: Ecophysiology of Northern Spruce Species: The Performance of Planted Seedlings), 69 refereed scientific journal papers and chapters, 26 technical transfer papers and 4 patents. Steve holds a Bachelor of Science degree in Forest Resource Management from Southern Illinois University, and a Master of Science degree and a Doctor of Philosophy degree from Colorado State University in Plant Physiological Ecology.