The phytopathogenic fungus Pyrenophora tritici-repentis is a causal agent of tan spot. Antagonistic microorganisms can be used as a non-chemical alternative treatment against the tan spot of wheat. Bacillus velezensis BZR 336 g and BZR 517 stains were selected as the most active microorganisms and potential biocontrol agents. We found that B. velezensis strains BZR 336 g and BZR 517 exhibited antagonistic activity against P. tritici-repentis Kr-15/2016 in vitro: they inhibited mycelium growth by 72.4–94.3% and caused its degenerative changes. Treatment of seeds and plants with strains BZR 336 g and BZR 517 provided a biological efficiency of 31.2–38.4% against tan spot, while artificial inoculation of plants provided only 28.4–43.8% biological efficiency. Treatment of seeds and plants with BZR 336 g and BZR 517 in a three-year field trial demonstrated 24.6–50% biological efficiency. BZR 336 g and BZR 517 provided 5.0–7.6% additional yield. We conclude that BZR 336 g and BZR 517 are promising options for novel bioproducts that can control P. tritici-repentis tan spot.

As a result of stage screening, there were selected promising bacterial strains to create laboratory samples of biological products on their basis to protect winter wheat from the causative agents of fusarium root rot. The purpose of the work is to determine the growth-stimulating and protective effect of laboratory samples of Bacillus subtilis BZR 336g and B. subtilis BZR 517 on winter wheat plants, as well as to determine the antagonistic effect of strains on Fusarium fungi. As a result of the work, there was established a positive effect of laboratory samples on the growth, development and germination of plants in greenhouse conditions and the ability to significantly inhibit the mycelium of phytopathogenic fungi F. graminearun, F. culmorum and Microdochium nivale in laboratory conditions. The study of the samples artificially infected in a climatic chamber showed not only a high protective effect of these laboratory samples, but also made it possible to determine the regimes for their use. The conducted tests prove the viability of new bioagents as environmentally friendly plant-protective products.

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The article presents some aspects of the interaction between biocontrol Bacillus subtilis strains and phytopathogenic fungi Fusarium and Pyrenophora. The presence of antifungal metabolites complexes in the culture fluid of the strains, including surfactin and iturin A has been found. The nature of the changes in the mycelium of phytopathogenic fungi is examined when co-cultivated with B.subtilis strains.

The insecticidal activity of strains from DBK of the Federal State Budget Scientific Institution VNIIBZR “State Collection of Entomoacarifagi and Microorganisms” was studied with respect to the test object Galleria mellonella L. and with respect to the target insect Cydia pomonella L. It was revealed that strain BZR 14 is promising for further study and development of a laboratory sample based on it.