Management of plant parasitic nematodes with antagonistic plants in the forest-savanna transitional zone of Ghana

Objective: Usage of synthetic agro-chemicals continues to threaten the environment and mankind. This study was done to offer the peasant farmer with a sustainable nematode management option. Methodology and results : Mucuna pruriens L., Tithonia diversifolia (Hemsl.) Gray, Solanum lycopersicum L. (control) and a clean fallow treatment were established in a randomized complete block design (RCBD). To evaluate their reaction to Meloidogyne spp., Pratylenchus brachyurus , Helicotylenchus multicintus , Rotylenchulus reniformis , Paratrichodorus minor and Tylenchulus semipenetrans : root gall index (RGI), population per 200 ml rhizosphere soil and one gram of root samples were analyzed. M. pruriens and T. diversifolia were antagonistic to Meloidogyne spp., P. brachyurus, H. multicintus and R. reniformis, but S. lycopersicum was a favorable host to the four nematode species. M. pruriens reduced populations of Meloidogyne spp. and P. brachyurus in root samples by 93 and 95% while T. diversifolia reduced populations by 86 and 87% respectively, compared to the control treatment. Their nematicidal potential was further demonstrated by lower root gall indices ( M. pruriens recorded 0.5 compared with tomato which recorded 8.8), and population per 200 ml rhizosphere soil (M. pruriens recorded 49 and 42 for Meloidogyne spp., and Pratylenchus brachyurus respectively, compared with tomato which recorded (166 and 227) respectively. Conclusion and application of findings: The spreading leguminous crop M. pruriens and the erect Asteraceae T. diversifolia were antagonistic to plant parasitic nematodes under the conditions of this study. Mucuna pruriens is a more favorable management candidate because of its potential to fix atmospheric nitrogen, smother noxious weed species and reduce the adverse effects of soil erosion. The use of antagonistic plants is environmentally acceptable. The two candidates are readily available in Ghana and could fit in the farming systems of peasant farmers. They could be included in a rotation system where they would be cultivated first and harvested before the cultivation of the economic crop.