TOXICITY OF SOME PLANT EXTRACTS FOR MELOIDOGYNE INCOGNITA

Abstract

The effect water soluble extracts of the roots of siam weed (Chromolaena odorata) castor (Ricinus communis), tomato (Lycopersicon esculentum cv. Ife 1) and cowpea (Vigna unguiculata ssp unquiculata cv. Ife Brown) on root-knot nematode, Meloidogyne incognita was studied in vitro. All the concentrations of the root extract tested were toxic to the nematode larvae. The extracts also inhibited the hatching of the eggs into larvae, extracts from C. odorata being particularly effective. Extracts from roots of R. communis were most toxic followed by C. odorata while those from tomato and cowpea were less toxic.

It is suggested that water soluble root extracts of C. odorata could be used to control root-knot nematodes in nursery beds in raising vegetable crops that are to be transplanted to the field later.