Growth Promotion and Biocontrol Potential of Some Isolated Soil Fungi against Brown Root Rot (Fomes Lamoensis) Disease of Tea in Barak Valley of Assam India

Biological control of plant pathogens involves antagonists are biological agents with the potential to interfere in the life process of the plant pathogens. Therefore these are important inputs for sustainable agricultural. In the experiment, Plant growth promoting fungi (PGPF) were isolated from tea rhizosphere soil. Isolated PGPF were screened for efficacy against the brown root rot pathogen (Fomes lamoensis) in vitro. From the study, four isolates namely Trichoderma viride, T. harzianum, T. citrinoviride and Aspergillus niger were exhibited good antagonistic activity against the pathogen. Later, these four selected isolates were examined for their ability to promote growth and disease suppression in pathogen infested soil under nursery conditions. It was found that the treatment in which the tea plants treated with the pathogen only have shown more disease incidence whereas the plant treated in pathogen infested soil with BCF, were found plants longer survival, healthy upto 120th days of observation. Besides disease reduction, It was also observed that plant treated with BCF viz. Trichoderma viride T. harzianum and T. citrinoviride have shown tremendous growth promotion ability in terms of shoot height, root length, biomass of shoot and root etc.