Plant parasitic nematodes were caused serious problems to the cultivated crops (Sasser and Frackman, 1987). These were not only suppressing plant growth but also interfere in the nodulation, nitrogen fixation and adversely affect the overall yield. During in vitro study leaf extracts of C.
procera was found highly deleterious to M. incognita juveniles (Singh et al. 2001). This is due to metabolites present in the plants as a potential source of nematicidal compounds. Many of them have been found in plants as source of alkaloids, diterpenes, fatty acid, glucosinolates, isothiocyanates, phenols, polyacetylenes, sesquiterpenes and thienyls, which are generally safe for the environment and humans (Chitwood 2002).
Different plant extracts have been tested by different scientists for their nematicidal properties (Netscher and Sikora, 1990; Akhtar, 1999). After that effect of chopped leaves of all tested plants with combination of nematicide in pot condition also found highly efficacious against root-knot nematode M. incognita affecting tomato. It was concluded that all the tested plants have nematicidal properties (Sosamma and Jayasree 2002). Moreover, the nemato-toxicity due to presence of some chemicals in the extracts of plants cannot be ruled out. All the treatments significantly reduced the root-knot index caused by M.
incognita. Among the tested plants against the root-knot nematode C. procera was found most effective as organic amendment (Ramakrishnan et al., 1997). The highest reduction in root-knot development was found in amended with C. procera leaves (50 g) with carbofuran followed by increase in growth tomato plants. Nematicides are generally recommended for the control of root-knot nematodes and targeted by 48% of globally use across crops (Coyne et al. 2009) but these are costly and produce environmental hazards (Zureen and Khan, 1984).
High cost of nematicides were not afforded by farmers and to overcome this condition, new alternative strategies was undertaken to control root-knot nematode population and disease intensity. This may be partly due to the reduction in root-knot development and partly due to fact that organic additives also served as manures. Thus, it can be concluded after the thorough study of above mention observation that chopped leaves alone and in combination with carbofuran could be of great use in solving of some of nematode problems. As these phyto-chemicals are easily available in wild condition and do not harm environment. Hence, the present study has been carried out to evaluate plant parts for their nematicidal properties against root-knot nematode M. incognita.