| dc.description.abstract | The parasitic flowering plants, Striga gesnerioides (wild.) Vatke and Alectra vogelii (Benth.), cause substantial yield reduction in cowpea in the dry savcannas of sub-Saharan Africa. Alectra is more prevalent in the Northern Guinea savanna and Southern Sudan Savanna of West Africa, as well as in East and Southern Africa whereas Striga is mostly found in West and Central Africa. However, both are fast spreading beyond these limits. Collaborative studies with national and regional programs have revealed the presence of five strains of Striga generioides of which strain 1 is presently found in Burkina Faso, strain 2 in Mali, strain 3 in Nigeria, strain 4 in Benin Republic and strain 5 in Cameroon. A local landrace, B301 in Botswana, confers complete resistance to Striga and Alectra in Burkina Faso, Cameroon, Mali, Niger and Nigeria. However, it has moderate levels of resistanceto yhe strain from Benin Republic. Other lines such as IT81D-994-IT89KD-288, 58-57, and Gorom local confer complete resistance from Benin Republic and Burkina Faso. Therefore, crosses were made among the selected complementary parents and a number of new varieties have been developed with combined resistance to Alectra as well as the five strains of Striga. Most of these lines also serve as a false host for Striga hermonthica reducing its seed bank in the soil when grown as an intercrop or in rotation with cereals. |
