Striga asiatica

Striga asiatica, the Asiatic witchweed or the red witchweed, is a hemiparasitic plant in the family Orobanchaceae. It is native to Asia and sub-Saharan Africa, but has been introduced into other parts of the world including Australia and the United States. Asiatic witchweed is a serious agricultural pest, as it parasitises important crop species, including corn, rice, sorghum, and sugar cane, often causing substantial yield reductions.

While it is native to Africa and Asia, it is invasive in farmlands of Kenya, Tanzania and Uganda.

In the US, this witchweed was discovered in the Carolinas in 1956. It is considered an invasive agricultural pest, and a vigorous eradication campaign has reduced the affected area by 99% [from 450,000 acres (1,820 km²) to about 3,400 acres (1,400 ha)].

Biological control can be achieved by growing a Desmodium (tick-trefoil) undercrop (see push–pull technology). The trefoil can be used as green manure or animal fodder after the harvest.