A range of concentrations of a number of herbicides was tested in field trials, for the control ofChromolaena odorata(L.) R.M. King and H. Robinson. The results obtained show that triclopyr, 2,4,5-T and tebuthiuron were consistently the most effective, regardless of application time or site. A dose-related response was evident in the treatments, the higher the concentration the greater the percentage mortality ofC. odorata.Application during late summer (March) resulted in greater mortality than early summer (December) application. Tebuthiuron and in one case, imazapyr, caused mortality of plantation trees. Based on these studies, triclopyr was adjudged to be the most suitable herbicide for the control ofC. odorataoccurring in a number of situations.S. Afr. J. Plant Soil1986, 3: 66–70