Herbicide (2,4-D), heavy metal [Pb(NO3)2] and plant competition (Bidens pisola) had no significant effect on the relative allelopahtic potential of volatile oil from Ageratum.

• 除草剂(2,4-D)和重金属[Pb(NO3)2]对胜红蓟挥发油的化感作用无明显影响。