Allelopathic effects of Polygonum aviculare L. III. Isolation, characterization, and biological activities of phytotoxins other than phenols [Prostate knotweed, Cynodon dactylon, bermudagrass]

The authors have isolated potential inhibitors from P. aviculare residues and soil under Polygonum stands, and none of these occurred in soil under Cynodon dactylon stands. GC-MS analysis revealed that these additional inhibitors are long-chain fatty acids with 14-22 carbons. Nine were identified in P. aviculare residues and seven in soil under P. aviculare . Sodium salts of all the identified fatty acids inhibited seedling growth of C. dactylon and at least some test strains of the nitrogen-fixing bacteria, Azotobacter and Rhizobium .