Allopathic effects of aqueous extracts from leaves of four invasive compositae plants on seed germination of Cynodon dactylon.
Objective: The present paper aimed to provide basic data and theoretical reference for the feasibility research and technological development of the replacement control of the relevant invasive plants by using Cynodon dactylon. Method: Using assays with petri dishes and filter papers, the effects of the aqueous extracts from leaves of four invasive plants (Argeratina adenophora, Conyza Canadensis, Chromolaena odoratum and Tithonia diversifolia) with different concentration (0.00, 0.25, 0.50, 1.00 and 2.00 g.L-1) on the germination rate, germination potential and allopathic effect index of Cynodon dynodon seeds were investigated and compared. Result: Aqueous extracts from leaves of four invasive plants had significant inhibitory effects on seed germination of Cynodon dynodon; and the inhibitory effects increased with the corresponding concentrations. Moreover, at the low or medium concentrations (0.25, 0.50 and 1.00 g.L-1), the four invasive plants showed significantly different inhibitory and allopathic effects on the seed germination of Cynodon dynodon; while at the high concentration (2.00 g.L-1), the most powerful inhibitory and allopathic effects arose from Chromolaena odoratum, but there was no significant differences among the other three plants. Conclusion: The four invasive plants had a strong inhibitory allopathic effect on Cynodon dynodon, and appropriate measures should be taken to avoid or alleviate these negative effects for the application of Cynodon dynodon in the replacement control and ecological restoration.