Parasitic Weeds: A World Challenge

While witchweed is nearing eradication in the United States, it continues to thrive in other parts of the world, especially in Africa, together with other witchweed species. The continuing problems from witchweeds and other parasitic weeds, the broomrapes, dodders and mistletoes, are outlined, including their extent, the degrees of damage caused, and the difficulties in their control. While a small minority are being successfully controlled by the use of immune varieties, most are currently controlled by existing techniques only partially, or on a local basis, and they may even be spreading or intensifying. The challenges they present are emphasised. Nomenclature: witchweed, Striga asiatica (L.) Kuntze; dodders, Cuscuta spp.; broomrapes, Orobanche spp.; mistletoes, Viscaceae, Loranthaceae.