Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

Allelopathic interactions between rubber tree and Chromolaena odorata as measured by seed germination and/or seedling growth of the two species.

Abstract

Chromolaena odorata (L.) R.M. King & H. E. Robinson (Asteraceae) is one of the most important invasive alien plants in Hainan, China. To understand the allelopathic effects between rubber tree, Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg. (Euphorbiaceae), and C. odorata, an experiment was conducted to evaluate the effects of extracts of three types of rubber tree leaves on seed germination and seedling growth of C. odorata. Extracts of C. odorata stems plus leaves and roots were also evaluated on the effect on seedling growth of rubber trees. The studies showed that 0.25 g/ml extracts of all types of rubber tree leaves (mature, light-green and bronze), significantly inhibited the seed germination rate of C. odorata and resulted in a significantly lower germination index. Seedling growth of C. odorata was only significantly inhibited by extracts of light-green rubber leaves at 0.125 g/ml and bronze leaves at 0.25 g/ml. However, seedling growth of C. odorata was greater with exposure to most extracts of rubber tree leaves than those seedlings in the control treatments. This indicates that rubber tree leaves could inhibit seed germination of C. odorata but does not inhibit seedling growth of C. odorata. Extracts of C. odorata stems plus leaves at 0.25 g/ml significantly promoted rubber seedling growth. This suggests that the leaves and stems of C. odorata are good green manure that should promote rubber tree growth. This may also be a way to control C. odorata.