American ginseng (Panax quinquefolius L.) produces natural products called ginsenosides. The biggest challenge Ontario commercial ginseng farmers face is ginseng replant disease. To understand the function of ginseng root exudates, ginsenoside accumulation and persistence over time were investigated. Currently, no reliable ginsenoside specific extraction method that characterizes changes in soil chemistry exists. Ginsenoside extraction protocol optimization was required to determine how ginsenoside composition changed over time. Overall, protocol optimization resulted in a 30% increase in yield of ginsenosides compared to previous extraction protocols. In the ginseng gardens, ginsenoside accumulation occurred slowly and did not reach significantly measurable amounts until the end of the second growing season. Until that time, only trace amounts of ginsenosides were detected, but with no pattern of persistence. High levels of variation existed within sites, reflecting the nonuniform distribution of ginsenosides within garden soils. Future sample collection will solidify patterns seen in these fields.
