Plant parasitic nematodes associated with three medicinal plants and the pathogenicity of root-knot nematode

A survey of plant parasitic nematodes carried out in the rhizosphere of Ammi visnaga Lamark, Costus speciosus (Koen Ex. Retz.) Sm. and Solanum indicum L. in the crop museum and fields revealed the occurrence of Tylenchus sp., Tylenchorhynchus vulgaris: Hoplolaimus sp., Helicotylenchus sp., Pratylenchus thornei, Rotylenchulus reniformis, Longidorus pisi and second stage juvenile of Meloidogyne species. Pathogenicity test undertaken in a glasshouse with root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood, with different initial levels revealed signficantly low plant growth and suppressed root development in all the three medicinal plants. Damage varied proportionally to the nematode initial density and nematode reproduction was inversely proportional to initial density.