Review of the status and integrated control of the invasive alien weed, Chromolaena odorata, in South Africa

Chromolaena odorata (L.) King & Robinson, a perennial, semi-woody, herbaceous scrambling shrub of neotropical origin, is an invasive weed of agriculture, forestry and conservation in many parts of the world. Although considered beneficial in parts of central Africa, in southern Africa it rapidly degrades indigenous forests and savannas and is a weed problem in commercial plantations. Research has shown that C. odorata is easily killed by herbicides applied to the foliage, stumps or to the soil at the base of the plant, or by mechanical or cultural means. A cost-effective integrated control and. management strategy has been developed in South Africa which incorporates rehabilitation by oversewing or natural succession and makes provision for judicious follow-up control, Notwithstanding these efforts, the spread of the weed has not been curbed. Successful biological control remains the only viable solution for reducing the current and potential impact of C. odorata in southern Africa.