Management of the root-knot nematode Meloidogyne incognita in tea by two plant extracts, in Tripura, India
AbstractExperiments were undertaken under in vitro and in vivo conditions to assess the nematicidal activity of the indigenous medicinal plants Glycosmis pentaphylla and Holarrhena antidysenterica on Meloidogyne incognita. Leaf extract of G. pentaphylla and bark of H. antidysenterica showed strong nematicidal properties. Different concentrations (20, 10, 5, 1, 0.5%) of G. pentaphylla leaf extract showed greater ovicidal activity on the egg masses and larvicidal activity on juveniles of M. incognita (98.1% to 35.9% inhibition) than those of bark extract of H. antidysenterica (84.3% to 28.3% inhibition) at the same concentration. The percentage mortality of the nematode juveniles increased with the rise in concentration of the plant extracts and time of exposure. Amendment of the soil with chopped leaves of G. pentaphylla reduced the reproduction of M. incognita and improved growth of tea more than did bark extract of H. antidysenterica.