Sequential extraction and chromatographic procedures were used to isol
ate inhibitors of yellow nutsedge growth from sweet potato periderm ti
ssue. Most of the inhibitory activity was found in a single high press
ure liquid chromatography peak that contained 1.2% of the periderm dry
weight. Concentration-response data indicated that yellow nutsedge is
highly sensitive to this fraction. Several other fractions inhibited
yellow nutsedge root growth, but they did not compose a major portion
of the inhibitory capacity of the periderm extracts.