Nematicidal activities of Cannabis sativa L. and Zanthoxylum alatum Roxb. against Meloidogyne incognita

Because of being costly and pernicious to the environment and human health, the use of nematicides has become prohibitive in many countries and the management of plant parasitic nematodes using antagonistic plants can be a very attractive alternative. In the present studies the effectiveness of aqueous extracts of Cannabis sativa and Zanthoxylum alatum was assessed on hatching, mortality and infectivity of Meloidogyne incognita at different concentrations viz. S, S:1, S:5, S:10, S:25, S:50 and S:100. Both the plants had significant effects on juvenile mortality and hatching inhibition in a dose-dependent manner. Mortality and hatching inhibition caused by C. sativa were significantly higher than that of Z. alatum. Time duration also affected mortality and hatching inhibition significantly. Significant inhibition in invasion of M. incognita juveniles on cucumber cv. Royal Sluis was observed by different treatments with extracts. M. incognita juveniles exposed to ‘S’ extracts of C. sativa and Z. alatum for 24 and 48 h caused no infection. Exposure for 12 and 6 h caused more than 95 and 90% reductions in infectivity of M. incognita juveniles respectively. Similarly, soil drench and root dip treatments also caused significant reductions in infection. Reduction in infectivity was found to be significantly higher with extracts of C. sativa as compared to Z. alatum and decreased in a dose-responsive manner. The results of the studies showed that the extracts of test plants, commonly found locally, possess high potentials for the control of root-knot nematodes and could be the possible replacement for synthetic nematicides.

► Cannabis sativa and Zanthoxylum alatum caused mortality and hatch inhibition.
► Mortality and hatch inhibition of Meloidogyne incognita were dose-dependent.
► Both the plants caused significant reduction in infectivity of the nematode.
► Maximum reduction in infectivity was caused with root dip treatment.
► Results with C. sativa were significantly better than those with Z. alatum.