Evaluation of Organic Soil Amendments on the Growth and Yield of Meloidogyne incognita on Cowpea Plants.

Abstract

Pot experiment was conducted in screen house to evaluate the efficacy of the leaf powder of neem (Azadirachta indica), swallow-wort (Calotropis procera), kassod tree (Cassia siamea), eucalyptus (Eucalyptus gigantea) and locust bean tree (Parkia biglobosa) in the control of Meloidogyne incognita on cowpea and their potency in growth and grain yield improvement. Four different doses viz. 25, 50, 75 and 100g of each of the leaf powder was separately mixed with 4kg of soil in a 25cm diameter plastic pot. Non-amended pots served as control. Three cowpea seeds were sown in each pot but the seedlings were thinned to one plant per pot six days after emergence. Each seedling was inoculated with about 3000 freshly hatched juveniles of Meloidogyne incognita two weeks after sowing. The experiment was laid out in completely randomised design with five replications and data obtained was analysed using ANOVA and means were significant were separated using the Duncan’s multiple test. The result of the study showed that all the treatments significantly (p<0.001) reduced root galling, nematode multiplication and improved plant growth and grain yield. Although all treatments were effective in reducing root galling and nematode population, application of Azadirachta indica leaf powder gave the highest reduction in nematode population, followed by Calotropis procera, Cassia siamea, Eucalyptus gigantea and Parkia biglobosa.

Key words: Cowpea, Meloidogyne incognita, Azadirachta indica, Calotropis procera, Cassia siamea, Eucalyptus gigantea and Parkia biglobosa