Impact of foliar herbicides on germination and viability of Siam weed (Chromolaena odorata) seeds located on plants at the time of application

Abstract

A field study was undertaken to determine the effects of foliar spraying on germination and viability of Chromolaena odorata (L.) King and Robinson (Siam weed) seeds at three different stages of maturity. Viability of Siam weed seeds was not significantly affected by herbicide application, irrespective of the stage of seed maturity. However, some
inhibition of germination occurred. The application of herbicide reduced germination of intermediate seed by 65% compared with the unsprayed control. These results suggest that effective control will be more likely if plants are sprayed and killed prior to flowering.