Allelopathic Characteristic of a Noxious Weed Leptochloa chinensis

Leptochloa chinensis (L.) Nees, is known as a noxious weed species in upland and lowland crop cultivation, and has naturalized in many countries as an invasive plant species. In this study, the allelopathic characteristic of L. chinensis was evaluated to understand its invasiveness. An aqueous methanol extract of the above-grand parts of L. chinensis suppressed the growth of weed species; Echinochloa crus-galli (L.) Beauv., Vulpia myuros (L.) C. C. Gmel. and Lolium multiflorum Lam., and crop plants; cress (Lepidum sativum L.), lettuce (Lactuca sativa L.) and alfalfa (Medicago sativa L.). Significant reductions in the growth were observed as the extract concentration was increased. The effectiveness of the extract varied with the test plant species. The present research suggests that L. chinensis may have allelopathic characteristic and the characteristic of L. chinensis may contribute its invasiveness.