Bourma Dembele, Amadou Diarra, John S. Caldwell, Brhane Gebrekidan
In the second year of on-farm research on control of the parasitic weed Striga hermonthica, trials on improved intercropping practices for millet / cowpea association and three sorghum varieties selected for resistance to Striga spp.were conducted during the 1996/1997 growing season in four villages in two zones of north central Mali. In the northern Mourdiah zone, planting the Striga resistant cowpea variety ‘IT 89KD 245’ in either alternate rows (“inter-row” arrangement) or alternate hills (“intra-row” arrangement) with millet resulted in 61-80% reductions of Striga counts compared to millet grown in pure stand. The “intra-row” arrangement had 20-30% higher yield than the control in both villages, but the “inter-row” arrangement decreased yield in one of two villages. Economic analysis is needed to determine the best choice between the two improved arrangements. The effects of the three introduced sorghum varieties on Striga counts and their yields were inconsistent between two villages in the Sirakorola zone, but the variety ‘Malisor 92-1’ showed tolerance of Striga by maintaining yield equivalent to the farmer variety under 2.4- 3.5 times higher Striga infestation in one village. While the adoption of varieties with such tolerance to Striga could have benefits for food production, it also could lead to a build-up of Striga population. The third year of these trials on 23 farms is in currently progress in the 1997-1998 agricultural season, which will end in January 1998.