Leguminous cover crops are promising as Meloidogyne spp. suppressants but where populations of mixed species occur, their potential remains uncertain. When inoculated with a Meloidogyne arenaria-incognita-javanica complex in a glasshouse experiment, Mucuna pruriens and Crotalaria spectabilis, were poor or non-hosts, did not gall and plant height and shoot biomass were not affected. 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. In ancillary experiments, M. pruriens, C. retusa and C spectabilis inhibited hatching of eggs, caused juvenile mortality, decreased population density and roots were either not invaded by juveniles or invasion was minimal.