Biocontrol Efficacy of Trichoderma and Bacillus Isolates against Sclerotium rolfsii under in vitro Conditions

Background: Sclerotium rolfsii is a polyphagous pathogen which is uneconomical and difficult to control due to its broad host range and persistence due to its tough resting structures, i.e., sclerotia. Chemical control has been supplanted by biological phytopathogen control. Antibiotic microorganisms are regarded as one of the viable management techniques in an integrated approach for ecofriendly management. Methods: Twenty three Trichoderma spp. and twenty one Bacillus species were isolated at Groundnut Pathology Laboratory, ICRISAT, Patancheru from rhizospheric soils of Telangana during rabi 2022-23 and 2023-24 and examined for antagonistic activity against Sclerotium rolfsii in an effort to design an effective biocontrol system for the management of Sclerotium rolfsii in groundnut. Result: The highest antagonistic activity against Sclerotium rolfsii has been observed in Trichoderma viride and Bacillus cereus. In the dual culture assay, Trichoderma viride and Bacillus cereus inhibited Sclerotium rolfsii by up to 65.33 per cent and 58.22 per cent, respectively. In the metabolites assay, Trichoderma viride and Bacillus cereus inhibited Sclerotium rolfsii by 63.33 per cent and 55.40 per cent, respectively. Thus, Trichoderma viride and Bacillus cereus displayed promising biofungicidal capabilities against the stem rot pathogen. ​