cover crops with an initial slow growth habit such as P. phaseoloides which has less aggressive growth habit and competition. However, in this present study, grain yield in P. phaseoloides plots was much lower than that of M. pruriens var. utilis which suggests some degree of competition by P. phaseoloides. Low cassava tuber yield obtained under S. guianensis, M. pruriens var. utilis and M. jaspeada might be as a result of high competition for both above and below ground resources as all the cover crops climbed or spread aggressively to smother the cassava crop for about 20 weeks before their senescence. Chikoye et al (2001) also observed the same trend of result when cassava was intercropped with M. cochinch- inensis or P. phaseoloides. In this present study, M. preta plots produced the highest average tuber yield for both cropping seasons which is significantly different from the yields of other cover crops.
Conclusion
The cover crops showed varying potentials for weed supper- ssion. Significantly lower weed densities were obtained under S. guianensis and M. pruriens var. utilis at cassava harvest compared with P. phaseoloides, M. jaspeada and M. preta. These cover crops were easily established especially if planted early to receive enough rain. Average Cassava tuber yield was significantly high in M. preta plots.