Lesions by root rot are annually noted on the crops of spring wheat in the conditions of the Republic of Mari El. A special place in the technology of cultivation of any agricultural crop, in particular cereal crops should be given to the problem of optimizing the phytosanitary state of the soil and crops. In our republic, the soil used for the cultivation of spring wheat is mainly sod-podzolic and has a small variety of microbiocenosis. Such types of pests that previously did not cause noticeable harm to cultivated plants are often observed in agrobiocenosis. Chemicals significantly reduce plant damage by diseases, but do not improve the phytosanitary condition of the soil. Therefore, a special place in an integrated defense system is given to biological preparations in an integrated defense system. In recent years, interest in the use of microbiological preparations has increased. The aim of our research is to study the effectiveness of biological preparations Orgamika F and Trichodermin in the cultivation of spring wheat. Materials and methods. Seeds were pickled before sowing according to the instructions. The counts and analyzes were carried out according to generally accepted methods. The results of the study and discussion. The treatment of seeds with biological preparations contributed to the reduction of root rot of spring wheat. The biological effectiveness of the biological product Orgamika F was at the level of the chemical drug Sertikor (94.3–100 %). The biological preparation Trichodermin helped to reduce the spread and development of root rot of spring wheat. Its biological effectiveness was 80–90 %. Trichoderma fungi contained in the biological preparations of Orgamika F and Trichodermin have a positive effect on the micromycetic composition of the soil. They contributed to the activation of saprotrophic fungi and reduced the number of pathogens. The highest yield of spring wheat was obtained from the use of Orgamika F. The yield increase was 1.08 t/ha. Conclusions. Application of the biological preparation increases the profitability of spring wheat grain production.