An on-farm field trial was conducted to assess the residual effects of 2 multi-purpose trees (Sesbania sesban and Sesbania macrantha) and 3 cowpea cultivars (IT 90K-59, IT 18 and Kavara) grown in Striga asiatica-infested fields for 2 consecutive seasons, 1998/99 and 1999/2000 summer seasons on maize grain yield and Striga asiatica density. A three-way maize hybrid, SC 501, was used as a test crop. At two of the sites, there were no significant differences in the number of emerged S. asiatica plants, while plots previously planted to maize/Kavara and S. sesban supported the least number of emerged S. asiatica plants at 8 and 10 weeks after crop emergence. Maize grain yield was statistically the same at Mungoriwo, while grain yield for the other two sites was lost because farmers bulked the trials before the researchers could take the records.
