Predominance of invasive weeds in new habitat may be due to their chemical secretion and
contamination of soil. Changing the chemical compositions of soil by allelochemical secretion,
they alter the native flora and form the mono-species stands. This study was done to know about
the allelopathic interference of native species Artemisia dubia Besser. (one of which congener A.
vulgaris Linnaeus is invasive to Americas) on invasive weeds Ageratum houstonianum Mill,
Chromolaena odorata (L) King and Rob. and Mikania micrantha HBK. (native to Americas). For
this seed germination of selected invasive weeds was carried out in the leaf mulching of A. dubia
on soil and seedling lengths were measured. There was significant decrease in seed germination
of invasive weeds under study which indicates the adverse effect on germination. Germination
was dose dependent. Seedling germination was stimulating in M. micrantha for lower
concentration of leaf mulching while adverse effect had been recorded in case of A.
houstonianum and C. odorata.