author(s)
Jayita Hore, Kusal Roy and Asim Kumar Maiti

abstract
A field experiment was conducted to evaluate the bio-efficacy of Bio-Nematon (Purpureocillium lilacinum 1.15%WP) in comparison to carbofuran 3%G against root-knot nematode (Meloidogyne incognita) in tomato cv. Patharkuchi (local susceptible) at the C-Block Farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, Nadia, West Bengal during the main and late rabi season of 2016-17. Five treatments comprising rhizospheric soil drenching with Bio-Nematon 1.15%WP @ 46g, 57.5g and 69g a.i./ ha, root zone application of carbofuran 3G @ 1000 g a.i./ha and an untreated control were replicated four times. The study revealed that Bio-Nematon @ 57.5-69 g a.i./ha was effective and economic for the management of root knot nematode infestation along with simultaneous crop health improvement and fruit yield enhancement. Increase in fruit yield by 11.6% and 11.4% over untreated control was recorded with Bio-Nematon @ 69 g a.i./ha in the 1^st and 2^nd season, respectively. It implies that the fungus, P. lilacinum is a potential biological control agent of M. incognita. There was no detrimental effect of Bio-Nematon @ 46-69 g a.i./ha on the beneficial nematode population in the tomato field. The incremental cost benefit ratio (ICBR) revealed the superiority of all the doses of Bio-Nematon over the treated check and untreated control. The maximum ICBR was recorded in soil drenching with Bio-Nematon @ 69 g a.i./ha being, 1:9.33 and 1:12.89 in the main and late rabi crop, respectively. The study emphasizes that Bio-Nematon 1.15%WP @ 69 g a.i./ha can safely be recommended for the management of menacing infestation of root-knot nematodes in tomato crop.