Management of root-knot nematode, Meloidogyne incognita on tomato using extracts of indigenous plants of Nepal

Three indigenous plant species viz. Datura (Datura stramonium), Neem (Azadirachta indica) and Mugwort (Artemisia vulgaris) were evaluated against root-knot nematode, M. incognita, a major limiting factor in crop production, for their nematicidal potency under laboratory and greenhouse conditions. The results indicated that the aqueous neem leaf extract produced best results in larval mortality followed by datura and mugwort. Almost complete larval mortality (97.3%) was observed in 100% concentration of neem leaf extract as compared to datura and mugwort which exhibited 72.0 and 70.0%, respectively. In comparison with the effects of plant parts, leaf extract demonstrated greater nematicidal potential (97.3%) than seed kernel extract (73.3%) in larval mortality. The application of 20 g neem leaf powder proved effective in improving plant growth characters with maximum root and shoot length (61.0 cm) reducing root gall index (1.6%) comparing to the other treatment. Of the doses tested, application of higher doses were more effective than lower ones.