2019 Volume 57 Issue 3 Pages 75-81
Medicinal plants are potential sources of secondary metabolites which may possess allelopathic properties. Hence, we investigated the allelopathic potential of 12 Thai medicinal plants against the growth of cress and barnyard grass. The 12 medicinal plant extracts showed a significant inhibition on the growth of those test plants. The inhibitory potentials depended on the extract concentration and test plant species. Comparing the average growth inhibition, the extracts from Crateva adansonii strongly inhibited the cress shoots and roots (96.0 and 95.6％), followed by Phlogacanthus pulcherrimus (93.1 and 93.4％), and Cuscuta chinensis (92.3 and 91.5％). Meanwhile, the barnyard grass shoots and roots were strongly inhibited by the extracts of P. pulcherrimus (88.2 and 97.6％), C. chinensis (73.7 and 82.3％), and Acanthopanax trifoliatus (73.0 and 94.3％). However, P. pulcherrimus extracts had a high allelopathic potential against both test plants, suggesting that P. pulcherrimus may be a potential candidate for purification of allelochemicals.