Root-knot nematode (Meloidogyne incognita) management using botanicals in tomato (Lycopersicon esculentum)

Abstract

Root-knot nematode, Meloidogyne incognita, is the major limiting factor in tomato production in many regions of the world including Ethiopia. For its management, different plant species (botanicals) are being tried in different forms as an alternative to nematicides. The nematicidal potential of baker tree (Milletiaferruginea), bitter leaf (Vernonia amygodalina), parthenium (Parthenium hysterophorus), lantana (Lantana camara), Mexican marigold (Tagetes minuta), Mexican tea (Chenopodium ambrosioides), neem (Azadirachta indica) and pyrethrum (Chrysanthemum cinerariafolium) was assessedagainst M. incognitaon tomato under laboratory and pot house. Aqueous extracts of the botanicals (20 g/100 ml w/v) were evaluated at 1, 3 and 5% concentrations in the laboratory; and at 3 and 5% concentrations in pot-house. The majority of extracts caused high degree of reduction in juveniles hatching in the laboratory, especially @ 5% concentration. Mexican marigold leaf, bitter leaf, lantana leaf and baker tree seeds were the most efficacious (above 95% hatching inhibition). In pot house, application of botanicals was found to reduce the formation of galls, number of eggs/egg-mass and final nematode population density in the soil and increased plant height of tomato.Thus, Lantana and Mexican marigold appeared to be promising botanicals. However, further research is needed to evaluate their efficacy under field condition.