Stimulation of Witchweed Germination by Run-Off Water and Plant Tissues

Abstract
Water from several bodies of surface water and sections from several plants were collected from eastern North Carolina and bioassayed for stimulation of witchweed (Striga luteaLour.) seed germination. Stimulatory activity was detected in water from 22 of 29 different ponds, streams, and lakes and in sections from 118 (57 families) of 163 plant species. Witchweed germination stimulants evidently occur widely in nature.