XVI International Botanical Congess

Age of commercially harvested wild ginseng roots (N = 950) from 11 states ranged from one to 39 years (mean = 8.2, mode = 7 years). Roots from southern states had younger mean ages (mean + SE: KY = 6.8+0.2, AK = 7.4+0.3, GA 6.3+0.4) than those from northern states (WI 15.3+1.1, MN 12.3+1.2, NY 12.4+1.4.) Mean oven-dry root weight plotted over one-year age classes for all states produced a sigmoid curve that was fitted with a third order polynomial equation (r2 = 0.93). Root weight increased to about 20 years and then declined. Mean root weight for southern states (0.70g) was less than that for northern states (5.5g). As harvested roots become smaller younger plants are being harvested and the size of the wild population is being reduced. The shift in age structure to younger plants results in a reduction in fruit production.