Why is it a problem?
It causes serious degradation of the veld, lowering biodiversity and reducing the grazing capacity by being unpalatable to large herbivores.
Three herbicides have been registered for this invasive. It is important to note that destroying the above-ground parts of the plant by means of mechanical or chemical method can actually make the problem worse. This is because it stimulates the rhizomes to shoot and therefore produce more flowers. If this is done repetitively however, it is possible that the plant may become exhausted.
Biological control is more efficient as well as more cost effective. The rust fungus, Puccinia eupatorii, was introduced un South Africa and tests have shown that the rust has a significant impact on prohibiting plant growth. Other potential biological control agents, the flower-feeding moth, Cochylis campuloclinium, and the stem-galling thrip, Liothrips tractabilis, are under investigation. Mechanical control has proven to be ineffective in areas of high infestation, but are certainly appropriate where very small numbers of plants occur.
Where is it a problem?
This plant has invaded the grassland regions of the Gauteng, KZN, Limpopo, Mpumalanga and Eastern Cape provinces.