Fate of toxic potato glycoalkaloids in a potato field.

The toxic glycoalkaloids, alpha-solanine and alpha-chaconine, are present in all parts of the potato plant and are possibly transferred to the terrestrial environment. The amounts of glycoalkaloids in plant, soil, and groundwater were followed in a potato field to investigate their distribution and fate during the season. The amount of glycoalkaloids in the plants was up to 25 kg/ha during maturity and decreased to below 0.63 kg/ha during plant senescence. The glycoalkaloids were detected in the upper soil (up to 0.6 kg/ha); this amount accounted only for a minor fraction of the amount present in the plants. Maximum glycoalkaloid concentration of 2.8 mg/kg dry weight soil was detected in September. Dissipation during winter appeared to be slow because glycoalkaloids were still present in the soil in March. No traces of glycoalkaloids were detected in the groundwater (detection limit 0.2 microg/L). From these results, the leaching potential of the glycoalkaloids is evaluated to be small.