Plant sources of Chinese herbal remedies: Effects on Pratylenchus vulnus and Meloidogyne javanica

More than 500 plant species, used alone or in combination, are documented i n Chinese traditional medicine to have activity against helminth and micro- invertebrate pests of humans. We subjected 153 candidate medicines or their plant sources to multilevel screening for effectiveness against plant-para sitic nematodes. For extracts effective in preliminary screens, we determin ed time-course and concentration-response relationships. Seventy-three of t he aqueous extracts of medicines or their plant sources killed either Meloi dogyne javanica juveniles or Pratylenchus vulnus (mixed stages), or both, w ithin a 24-hour exposure period. Of 64 remedies reported as antihelminthics , 36 were effective; of 21 classified as purgatives, 13 killed the nematode s; of 29 indicated as generally effective against pests, 13 killed the nema todes. Sources of extracts effective against one or both species of plant-p arasitic nematodes are either the whole plant or vegetative, storage or rep roductive components of the plants. Effective plants include both annuals a nd perennials, range from grasses and herbs to woody trees, and represent 4 6 plant families.