Effect of plant extracts on hatching and mortality of rootknot nematode

Root-knot nematode (Meloidogyne spp.) is an important pest of vegetables. Overall, 5% global yield losses are guessed due to root-knot nematode only, which may be much higher in tropics and sub tropics. Experiments were carried out to study the nematicidal effect of different plant extracts namely neem (Azadirechta indica) seed kernel, neem leaf, neem cake, neem oil, marigold (Tagetes erecta), aak (Calotropis gigantia) and carbofuran on hatching and mortality of M. incognita larvae under laboratory conditions. Extracts of all six plants and one market chemical carbofuran showed toxic effect against M. incognita at varying degree. Mortality and hatching inhibition of M. incognita were directly proportional to the concentration of plant extracts and exposure period to each extract. Among all plant extracts, neem seed kernel showed most inhibitory effect followed by neem cake, aak, neem oil, marigold and neem leaf, respectively.