Nematicidal Activity of Essential Oils of Various Medicinal Plants Under in vitro Conditions

Nematicidal efficacy of various medicinal viz., turmeric (Curcuma longa), marwatulsi (Origanum majorana), mentha(Mentha arvensis), aonla (Phyllanthus emblica) and jatropha (Jatropha curcas) was evaluated in vitro against root-knot nematode, Meloidogyne incognita. Essential oil of these plants were extracted and tested against root-knot nematode at different dilutions i.e. 1: 5, 1: 10, 1: 20, 1: 40 and 1: 80. Oils of all plants showed nematicidal effect against M. incognita at varying degree. Percentage larval mortality and inhibition of egg hatching were directly proportional to the dilution of plant oils and exposure period to each extract. Oil of mentha (M.arvensis) was found to be more effective amongst all other plant oils in increasing mortality and inhibited the egg hatching.