Biocontrol potential & rhizosphere competence of Trichoderma harzianum against Meloidogyne incognita infecting tomato cv. Pusa ruby

One indigenous isolate of Trichoderma harzianum (ITCC accession number 6888) which was effective in causing Juvenile mortality in previous lab studies was tested for its bioefficacy against Meloidogyne incognita. Cell Free Filtrate of isolating in petriplate bioassay on pluronic gel exhibited significantly reduced J2 movement towards tomato root at 6h compared to water as a control. Soil application of T. harzianum ITCC 6888 @3% w/w could significantly reduce penetration of root-knot J2. The effectiveness of ITCC 6888 was seen in sterilised and unsterilized soil on tomato cv Pusa Ruby, as the isolate exhibited rhizosphere competence with a significant reduction in root galls, egg mass production, eggs/eggmass and reproduction factor in both sterilised and unsterilized soil. The effects of ITCC 6888 @ 3% w/w talc based formulation were at par with those of carbofuran (1kg a.i/ha) in reducing eggmasses/plant, and the effect of carbofuran was significant in Sterilized Soil but exhibited lowered effects in Un Sterilized Soil. ITCC 6888 was compatible with carbofuran application in soil, but no significant difference was observed in bioefficacy of the combination treatment. The number of M. incognita J2s recovered from soil 3 months after inoculation was significantly low in pots treated with ITCC 6888 alone or in combination with carbofuran, compared to untreated control. Thus this isolate holds the potential to develop into a biopesticide for field application as it reduced the nematode population significantly.