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In the present study, 12 varieties of tomato, viz., Arka Vikas, Damayanti, F-hybrid, Hybrid Padmarag, Hybrid Tripti, Marudam, Punjab chhoara, Pusa early dwarf, Punjab kesari, P.K.M.I, Roma and Pusa Ruby were screened for the presence of the root-knot nematode, M. javanica to obtain information on the varying degrees of resistances to tomato cultivars. All the cultivars of tomato tested were found to be infected with the root-knot nematode, M. javanica, however, to a varying extent. Consequently, there was a reduction in the growth parameters of cultivars leading to have an impact on the yield and quality of fruits. The cultivar, Marudam was found resistant while the cultivar the Pusa early dwarf was moderately resistant and rest of the 10 cultivars was highly susceptible.

The results of experiment clearly reveal that cadmium inhibited root penetration by the second stage juveniles (J2) of Meloidogyne incognita which subsequently affected the development of root galls in tomato. The heavy metal was highly injurious to tomato plants at all the concentrations tested for (7.5, 15.0, 30.0 and 60.0 ppm). The inhibitory effect on plant growth and other parameters (fresh and dry weight of plant, chlorophyll content of leaves, water absorption capability of roots) significantly increased with an increase in the concentration of the metal. It was further increased in the presence of the nematode.

All the cultivars of tomato tested were found to be infected with the root‐knot nematode, Meloidogyne incognita, however, to varying extent. There was also reducton in plant growth parameters accordingly. Further reduction in plant growth of tomato cultivars was recorded when plants also received the treatment with the heavy metal, lead, notwithstanding the fact that the presence of lead also reduced the root‐knot development. Tomato cv. Arka Vikas showed minimum reduction in plant growth with single or combined treatment with the nematode and the heavy metal.

Pollution Pathology has emerged as a distinct discipline which deals with the impact of pollutants on plants and its disease causing agencies. Pollutants have been found to adversely affect not only the plants but also the phytopathogens and above all their pathogenesis. The hitherto scattered information on this aspect has been reviewed in the present write‐up.