Allelopathic suppression by Conyza canadensis depends on the interaction between latitude and the degree of the plant’s invasion

ABSTRACT Allelopathic suppression of the growth of co-occurring plant species in invaded ecosystems is an important factor in some plant invasions. This study uses leaf extracts of the invasive plant species Conyza canadensis to determine its allelopathic effects along a latitudinal gradient, and under different cover classes and degrees of invasion, on seed germination and growth of Lactuca sativa, a sensitive bioindicator of allelochemicals. The allelopathic effects of C. canadensis on seedling height, root length, seedling biomass, germination percentage, germination potential, germination ...