In vitro study on the nematicidal activity of entomopathogenic bacteria against the root knot nematode Meloidogyne incognita

Abstract

National loss of Rs. 21,068.73 million has been estimated due to plant-parasitic nematodes in India. Among plant-parasitic nem-atodes, one of the major nematodes, root-knot nematodes (RKNs), are well-known diseases causing major losses in vegetable crops. An in vitro experiment was conducted to evaluate the nematicidal activities of the cell-free culture filtrate (CFCF) of ento-mopathogenic bacteria Photorhabdus spp. and Xenorhabdus spp. isolated from entomopathogenic nematodes Heterorhabditis indica (DH3) and Steinernema abbasi (CS-39), respectively. The applied doses were 90, 50, 25 and 10% CFCFs. The experiment was performed on the plant-parasitic nematode Meloidogyne incognita, and the % mortalities were determined at 6, 12, 24 and 48 hr intervals. The results of the present study revealed that 100% mortality was achieved after 48 hrs with a 10% filtrate of H. indica isolate DH3, while no significant result was achieved even after 48 hrs and at 90% CFCF of isolate CS39. There-fore, 10% CFCFs may be recommended for application in root-knot nematode-infected fields for the control.