Assessment of the effect of rate and time of application of rice-husk powder as an organic amendment on cowpea (Vigna unguiculata L.,walp) inoculated with cowpea mottle virus

Abstract

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 (CMeV). 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 (CMeV). 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 (CMeV). 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.