Management of Root Knot Nematodes (Meloidogyne incognita) on Cowpea with Plant Extracts

Screen house experiment was conducted to test the efficacies of leaf powder of neem (azadirachta indica), kassod tree (cassia siamea), eucalyptus (eucalyptus gigantea) and locust bean tree (parkia biglobosa) in the management of meloidogyne incognita on cowpea yield. in this study, 50g of each of the leaf powder was separately mixed with 4 kg of soil in a 25-cm diameter plastic pot. non-amended pots served as the control. cowpea seeds were sown in each pot and each seedling was inoculated with about 3000 freshly hatched juveniles of meloidogyne incognita two weeks after sowing. the experiment was laid out in a completely randomised design with five replications. the obtained data were analysed using anova and means, while the significance values were separated using the duncan multiple test. the result of the study showed that all the treatments significantly (p<0.001) reduced root galling and nematode population, as well as improved plant growth and yield of cowpeas. although all treatments were effective in reducing root galls and nematode population, application of azadirachta indica leaf powder gave the highest reduction in root galls (0.293) and nematode population (24), followed by cassia siamea, eucalyptus gigantea and parkia biglobosa. the findings recorded root galls and nematode population of 28.25 and 37.34, 29 and 48, and 30 and 53.34 respectively as compared to the control treatment, which recorded root galls of 107.75 and nematode population of 189.34.