Cornell University is a center of active research on the development of American ginseng (Panax quinquefolium) as a high-value forest farming product in the hardwood forests of eastern North America. An update on several current research projects was featured during the recent fifth North American Agroforestry Conference at Cornell.
Ginseng research is being conducted at the Arnot Forest near Ithaca, New York, which is managed by the Cornell Dept. of Natural Resources. Sugar maples at Arnot Forest are managed for maple syrup production, and ginseng is a compatible understory crop which benefits from the shade, leaf litter nutrients and improved soil moisture provided by the maple trees.
Several Cornell researchers were on hand to describe their current projects on ginseng. Their research has two goals: to reduce the collection pressure on wild American ginseng, and to determine optimal management requirements for producing it using “woods-grown” (forest farming) methods.
One project is seeking to characterize the optimal ecological and soil conditions for ginseng in its native habitat. Cornell senior extension associate Louise Buck described how the project has enlisted the aid of “shang hunters” (wild ginseng collectors), who have an intimate knowledge of where the best roots can be found, to collect soil samples from those sites.
That project is related to another study conducted by Cornell researchers Jillian Gregg and Todd Dawson which seeks to determine how climatic region, slope aspect and species composition of the forest canopy affect the growth and ginsenoside content of ginseng. Preliminary results indicate that microclimate or soil characteristics are likely to be more important than any of those factors.
Concurrent with the field studies, laboratory analyses are being conducted to quantify the ginsenoside content of ginseng roots that differ in age, shape, geographic origin, and whether they are wild or cultivated.
Ginsenosides are the biologically active chemicals in ginseng roots that produce a quantifiable physiological effect on mammals and therefore arethe basis for its medicinal value. The first step of this research is to develop a quick and easy method for measuring the seven most common and diagnostic ginsenosides.
The goal is to investigate whether or not the traditional criteria used to judge the quality (and therefore price) of ginseng roots, e.g. age, shape, color, are reliable indicators of ginsenoside content and thus medicinal value. Market price should logically be based on ginsenoside assays, and growers will receive a better return once they know how to grow ginseng to maximize its ginsenoside content.
Small plots have been established at Arnot Forest to demonstrate various cultivation methods and to evaluate the growth of ginseng from different geographic provenances. Young ginseng plants require 70-80% shade. During the first year of establishment plants are most susceptible to animal damage (e.g. slugs and rodents) and fungal pathogens (e.g. alternaria, phytophthora). Woods-grown roots are thinned to a final spacing of one per square foot and harvested after 7-10 years.
Several private organizations are cooperating with Cornell in these demonstration trials, including the New York State Ginseng Association and a newly formed growers' group, the North American Ginseng Association.