author(s)
Moumita Chakraborty, Gayatri Kumari Padhi, Subrata Chatterjee, Dhiren Chettri and Ajoy Kumar Mukhopadhyay

abstract
A field experiment was conducted for two consecutive years to assess the effect of infestation of root knot nematode on population of aphid and whitefly infesting tomato plants under three different nutrient regimes. The whole experiment was laid out in split plot design, with three main plots of different levels of fertilizer regimes i.e. recommended doses of fertilizer, 75% of the recommended dose and 50% of the recommended dose and four sub plots of different levels of pest infestation i.e. only root knot nematode, only insects, both root knot nematode and insects and the plot in which plants were subjected to no pest infestation. Population of root-knot nematode i.e. J2 per 200cc of soil, female root knot nematode and egg mass per 5 g of root were recorded at 30, 60 and 90 DAT. Aphid and whitefly population were observed on weekly interval. The study revealed that both below ground and above ground population were lower in plants infested by both as compared to the plants subjected to sole infestation of these pests. The observation taken for yield of tomato were comparatively higher in the plots with no pest infestation and were the lowest in the plants subjected to infestation by both root knot nematode and sucking insects. The interaction of main plot and sub plot treatments had significantly influenced population of root knot nematode and sucking insects as well as yield of tomato plants.