Dimethoate 0.5% for 6 h was the most effective dip for suppressing the root-knot nematode,Meloidogyne incognita(Kofoid and White, 1919) (Chitwood, 1949). It was better than all the other treatments except 0.025% dimethoate for 6 h. Dimethoate at 0.1 and 0.2% and 0.2% parathion and diazinon as 6 h root-dips were phytotoxic. Diazinon controlled the nematode poorly and malathion was ineffective.