A study of the allelopathic effects of Centaurea maculosa on seed germination and rhizomal growth of associated species.

Abstract

Allelopathy can be defined as ""any direct or indirect harmful effect by one plant on another through the production of chemical compounds that escape into the environment."" We studied the allelopathic effects of spotted knapweed, Centaurea maculosa, on associated species. The rhizomes of Poa compressa and a Bromus species, and the seeds of Hypericum perforatum, Anemone virginiana, and Centaurea maculosa were treated with leachate from C. maculosa. We predicted that if there is an allelochemical in the roots of C. maculosa, the seeds and rhizomes which received treatment leachate would grow less than seeds and rhizomes which received no treatment. Significant evidence of allelopathy was observed only in the growth rate of Poa compressa rhizomes.