Leguminous cover crops in nematode suppression and soil improvement

Nematodes cause yield losses to cultivated crops. Currently, synthetic chemicals are the most effective management strategy, but this option threatens man and the environment. Phytochemicals provide a sustainable management option. When inoculated with a Meloidogyne arenaria-incognita- javanica complex in a glasshouse experiment, Mucuna pruriens and Crotalaria spectabilis were poor or non- hosts. However, Dolichos lablab was highly susceptible. The root system of D. lablab stimulated population increase but the leaf eluant proved lethal. Thus, different parts of a plant contain different active ingredients or concentrations of compounds. A similar trend was observed in field trials at two locations. Okra cultivated on plots previously sown to M. pruriens, C. retusa and C. spectabilis had significantly lower gall, egg mass and susceptibility indices than the control treatment. The residual effect of M. pruriens controlled Meloidogyne spp., increased plant growth and resulted in significant 48% yield increase over the control treatment. This monograph would be beneficial to agricultural researchers, students, extension agents and farmers.