An improved technology for obtaining a biological product has been developed to prevent the occurrence of centers of infection by Heterobasidion annosum (Fr.) Bref. in the pine stands of Donbass. The technological process of obtaining a biological product includes liquid-phase fermentation of plant waste using a strain of the fungus Phlebiopsis gigantea (Fr.) Jülich. P-1-96; hydrolysis of plant raw materials with a liquid-phase fraction obtained during liquid-phase fermentation and containing enzymes that degrade cellulose and lignin; solid-phase fermentation in a layer of a mixture of products of liquid-phase fermentation and enzymatic hydrolysis of plant raw materials. The developed technology made it possible to shorten the technological cycle of obtaining a biological product and increase the yield of viable oidia to 6.5106 CFU/g.