采用培养皿滤纸法比较了南美蟛蜞菊（Wedelia trilobata (L.) Hitchc.）和蟛蜞菊（W. chinensis (Osbeck.) Merr.）水浸提液对萝卜（Daucus carota L.）和菜心（Brassica parachinensis Bailey）种子萌发和幼苗生长的化感作用. 结果表明：随着南美蟛蜞菊和蟛蜞菊水浸提液浓度的升高，萝卜和菜心的种子最大发芽率逐渐降低；相同浓度下，南美蟛蜞菊水浸提液对植物种子发芽势、发芽率和发芽指数的抑制作用小于蟛蜞菊；南美蟛蜞菊和蟛蜞菊对植物幼苗的生长影响表现为低促高抑的趋势，其中蟛蜞菊对受试植物的化感抑制作用较南美蟛蜞菊更强.
Allelopathic effects of aqueous extracts of Wedelia trilobata （L.)Hitchc. and Wedelia chinensis （Osbeck.）Merr. on seed germination and seedling growth of Daucus carota L. and Brassica parachinensis Bailey were investigated using the petri dish bioassays. The results showed: (1) the maximum germination rate decreased with increased concentrations of the aqueous extracts of W. trilobata and W. chinensis, and the time to reach the maximum germination rate was also delayed in varied degrees; (2) the inhibitory effect of aqueous extracts of W. trilobata on seed germination potential, germination rate and germination index of the tested plants was less than that of W. chinensis under the same concentration; (3) the aqueous extracts of W. trilobata and W. chinensis promoted the seedling growth of the tested plant at low concentrations and inhibited them at high concentrations, and the root elongation was more sensitive to the inhibitory effects of the donor materials; (4) comprehensive experiments showed that the inhibitory effect of W. chinensis on the tested plants was stronger than that of W. trilobata.