Bio-Efficacy of Purpureocillium lilacinum on Management of Root-Knot Nematode, Meloidogyne incognita in Tomato

The experiments were conducted to study the bio-efficacy of fungal bio-agent Purpureocillium lilacinum in three dosage, either alone or in combination with Farm Yard Manure (FYM) for management of root-knot nematode, Meloidogyne incognita in tomato. The effect of various treatment combinations on growth parameters of tomato plant, yield of tomato, population build-up of root-knot nematode, M. incognita as well as beneficial nematodes and phyto-toxic effect, if any, was observed. The treatment combination of pre-incubated Purpureocillium lilacinum @ 20 mg/kg of soil + FYM @ 10 g/kg of soil in pot experiment conducted in net house condition, enhanced the shoot length, root length, shoot weight and root weight of tomato plants to the tune of 35%, 47%, 45%, and 53% respectively over untreated control. It also reduced the number of galls, number of egg masses, root knot nematode population of pot soils and plant root by 62%, 71%, 66% and 67% respectively with lowest multiplication rate (0.95). Purpureocillium lilacinum @ 15 mg/kg of soil + FYM @ 10 g/kg of soil was found to be second best treatment with 32%, 44%, 44% and 47% enhancement of shoot length, root length, shoot weight and root weight of the tomato plant respectively. This treatment also recorded 53% less gall formation, 73% less egg mass production and 50% less soil nematode population and 59.5% less in nematode in plant roots as compared to untreated control. Basal application of pre-incubated P. lilacinum @ 3.0 kg/ha and 4.0 kg/ha along with FYM @ 1.0 t/ha during transplanting of 21 days old tomato seedling in open field condition were proved to be effective in management of M. incognita. Both the treatment combinations recorded enhanced yield (25.05% and 27.5% over untreated control) without exhibiting any adverse effect on beneficial nematodes and phyto-toxic symptoms on tomato plants. However, with the exhibition of better root colonization in the form of higher Colony Forming Units (3.33x10⁸CFU/g) in field soil and highest Incremental Cost Benefit Ratio (ICBR) of 1: 14.28, the basal application of P. lilacinum @ 3.0 kg/ha along with FYM @ 1.0 t/ha was proved to be the most bio-efficient and reasonable treatment in reducing population of M. incgnita in tomato.