Abstract
Field experiments were conducted at Gwagwalada in the Federal Capital Territory, Abuja, Nigeria during the 2002, 2003 and 2004 cropping seasons. Two varieties each of three leguminous crops, soyabean (Glycine max L.) (Samsoy 2 and TGX 1448-2E), cowpea {Vigna unguiculata (L.) Walp. (IAR 48 and dankurmi) and groundnut (Arachis hypogaea L.) (RMP12 and UGA2) were used as trap crops in maize. Two open pollinated maize varieties Acr 97 TZL Comp l-W (Striga resistant) and TZB-SR (Striga susceptible) were planted after cropping the varieties of the three leguminous crops either once or twice. Results indicated that the maize variety TZB-SR recorded a significantly higher Striga count, exhibited greater crop reaction syndrome of 22.5% in the first year and 15% in the second year rotation and produced 33.3% less grain yield than Acr 97 TZL Comp l-W. Maize grain yield was generally low after one year rotation, but it increased by an average of 55% after two years of cropping the legumes. While differences in the capacity of the legume varieties to stimulate Striga seed germination was only significant early in the cropping season of the first year, the reverse was the case after two years of cropping the legumes. The study reveals that the varieties of cowpea (IAR 48 and dankurmi) and groundnut (RMP 12 and UGA 2) were better candidate legumes for S. hermonthica trap cropping by rotation than others tested.
