The invention relates to an antagonist Trichoderma viridae strain Td50, deposited under number (P) 001158 to NCAIM Budapest, presenting a strong antagonistic character related to a series of phytopathogenic fungi and to a process for using the same for the bioconversion of marc resulting from ethanol manufacturing into a an antifungal biopreparation, by passing the marc resulting from ethanol manufacturing into a mixer to which 0.4...0.5% of potassium superphosphate is added for normalizing the potassium content, inoculating with 0.1% hydrogellified biopreparation based on Trichoderma viridae obtained by drying granules of Td50 fungi formed after having been cultured onto an agarized Weidling medium and then inoculated on a hydrogellified medium for industrial multiplication, for 7 days and maintaining the resulting composition for 7...8 days while stirring with 1 rot/h frequency for aerating the substrate, to result a highly efficient biopreparation for the phytosanitary management of vegetable waste.
