POPULATIONS AND DISTRIBUTION OF NEMATODES IN SOIL TREATED WITH MUCUNA PRURIENS (VELVET BEAN) AS MANURE

Abstract

Research has shown that Mucuna pruriens is useful in the management of some plant[1]parasitic nematodes. However, in Nigeria, M. pruriens is still underutilised in that capacity. Consequently, the effect of Mucuna pruriens manure on the populations of soil nematodes was examined. Seeds of M. pruriens were sown for 2, 4, 6, 8 and 10 weeks in 2 2m plots, arranged in Randomised Complete Block Design in three replicates. Plots without mucuna served as control. The plants were shredded, and incorporated into the soil and allowed to decompose for three and nine weeks. Soil samples were collected 2 from each 2m plot before incorporation of the mucuna plants and after the decomposition period for the assessment of nematode populations using standard procedures. Data were analysed using ANOVAat á . The Relative Importance Value- 0.05 RIV (%) was determined using the frequency and density of nematodes. The average populations of bacterivores, omnivores, fungivores and predators were 5643.30, 3472.80, 2070.00 and 1302.30, respectively after nine weeks of manure application and were significantly higher than 148.19, 80.83, 59.72 and 40.42, respectively before manure application, respectively. The population of herbivores increased significantly from 39.11 to 195.61 after three weeks of manure application, but reduced to 131.50 after nine weeks of manure application. At nine weeks after manure application, the bacterivores had RIV of 33.1 and the herbivores had the lowest RIV of 10.0. The results of this study suggests that Mucuna pruriens manure can be recommended for the management of parasitic nematodes in soil.