Efficacy of Different Oil–Cakes on The Incidence of Root–Knot Nematodes (Meloidogyne Javanica) on Tomato

India is the second largest producer of vegetables in the world. Tomato is the most important vegetable crop in India but the production of tomato is still lower in India as compared to developed countries due to various factors, of which root–knot nematodes are also a serious problem. During recent years, the root–knot nematodes (Meloidogyne spp) have become a cosmopolitan pest of economic crop plants. Chemical pesticides are hazardous to human health and environment so certain plants extracts have been used as pesticides to control different pests by various researchers. In the present investigation a comparative evaluation of five types of oil–cakes viz. Linseed, Karanj, Groundnut, Castor, and Mustard was carried out to study their effects in minimizing the population of Meloidogyne javanica on tomato at Muzaffarpur (Bihar), India. All oil cakes included in the trial caused a reduction in galling. The mustard cake was found most effective. There was minimum infestation (7.65 galls/gm of root weight) in mustard oil cake treated soil while maximum (70.08 galls/gm of root weight) in plants of untreated soil.