A comprehensive field survey was carried out in 2011 spanning thirty locations within the forest and savannah agroecologies of Kwara State, Nigeria. This was with the objective of having an overview of the prevalence of virus disease symptoms and to specifically identify the viruses infecting cowpea (Vigna unguiculata .L.) in Kwara State. Data were collected on the prevalence of some peculiar virus symptoms on cowpea plants on growing on farms in each location. Symptomatic cowpea leaves were also collected from each location for virus identification in the laboratory. The serological protocol employed for virus detection in the leaf samples was the antigen-coated plate Enzyme linked immunosorbent assay (ACP-ELISA) method. The results of the field survey indicated that the symptoms observed on the cowpea plants were peculiar to those associated with virus disease infection. The symptoms observed were leaf mottling (36.8%), mosaic (24.9%), leaf curl (15.6%), necrotic spots (8.2%) and other symptoms (14.5%). The result of the laboratory assay to detect the viruses present in the leaf samples revealed the presence of four (4) different viruses. The viruses identified were, Cowpea Aphid Borne Mosaic Virus (CABMV), Cowpea Yellow Mosaic Virus (CYMV), Blackeye Cowpea Mosaic Virus (BICMV) and Cowpea Mottle Virus (CPM o V). These viruses were detected infecting the cowpea plants in mixtures of two or three. These results are indicative of the presence of viruses in all the ecological zones of Kwara State where cowpea is cultivated.

A Screen house experiment using potted plants was carried out to assess the effects of time and rate of application of Rice-husk powder as an organic amendment on cowpea (Vigna unguiculata L Walp) cv. Ife Bimpe, that were mechanically inoculated with Cowpea Mottle Virus (CM e V). The results showed that the organic amendment was very effective on plants with soils amended with rice-husk powder, as the plants exhibited better yields and productivity. The amended plants also showed considerable less susceptibility to the virus pathogen compared to the non-amended plants. The results of the experiment further showed that the rate and time of application of the Rice-husk powder was a key factor in the ameliorative effect of this organic amendment in the suppression of the viral inoculum. An application rate of 0.50kg of Rice-husk powder per 10kg of soil two weeks before sowing the cowpea seeds was observed to confer on the plants the highest growth and yield attributes and also the least susceptibility to Cowpea Mottle Virus (CM e V). On the other hand, cowpea sown on soils amended at a lower rate of 0.125kg of Rice-husk powder per 10kg of soil two weeks after planting were found to have higher susceptibility to Cowpea Mottle Virus (CM e V). This is indicative that Rice-husk which is cheap, readily available and environmentally friendly offers a promising prospect in Agriculture both as an Organic amendment and in the control of virus disease in Cowpea if applied at recommended rates and time.

Potted experiment was carried out in the screenhouse of the Crop Protection Department, Faculty of Agriculture, University of Ilorin, Nigeria to determine the yield reaction of cowpea to single and mixed viral infection with Blackeye Cowpea Mosaic Virus (BICMV) and Cowpea Yellow Mosaic Virus (CYMV) at different inoculation regimes. The experiment was laid out in a complete randomized block design (CRD). The two viral inoculums (BICMV and CYMV), were mechanically inoculated to cowpea plants, singly and in mixtures at 2 and 4 weeks after planting (WAP). Plants which served as the control were only buffer inoculated. The results of the experiment showed that mixed inoculation with the two viruses, induced greater susceptibility to the viral pathogens in the plants, compared to single virus inoculations. The study also indicated that, early viral infection at

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