Allelopathic effects ofPolygonum aviculare L. II. Isolation, characterization, and biological activities of phytotoxins.

In earlier work, we found thatPolygonum aviculare had pronounced allelopathic effects against several test species. Four inhibitors were isolated from livingPolygonum plants, three of which were glucosides. Four different inhibitors were isolated fromPolygonum residues and soil underPolygonum stands, and none of these occurred in soil fromCynodon dactylon (L.) Pers. stands. Three of these were glycosides containing both fructose and cellobiose as the sugars. Color reactions of all the inhibitors indicated that they are phenolic in nature. All the inhibitors reduced seed germination and/or seedling growth ofChenopodium album L. Moreover some of them inhibited growth of different strains ofRhizobium andAzotobacter.