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The development of pathogen resistance and the relatively high cost of chemical fungicides dictate the necessity to develop alternative disease control strategies. These strategies include biological methods of plant protection. However, the effectiveness of biological plant protection depends on the biological agent's activity, which strongly depends on external physical factors. The applicant of biological remedies for seed inlay is one of the environmentally safe ways to combat seed and soil infection. However, nowadays, the impact of mechanical means during seed inoculation on the survival of microorganisms remains poorly studied. A laboratory installation has been created that makes it possible to imitate the working process of applying microorganisms to plant seeds during inlay, changing the pressure in the distribution system, the types of sprayers and the temperature of the working composition of the biological product with its further study in order to determine the number of living microorganisms remaining in it after processing. According to the results of the experimental data, graphical dependences were constructed showing the impact of pressure in the sprayer system, the temperature of the biological product and the type of spraying device on the viability of microorganisms. For microorganisms of RECB-50B (based on Bacillus sp.), RECB-14B (based on Pseudomonas putida), RECB-74F (Trichoderma viride) strains, the optimal parameters of the above factors were established during mechanical application of a biological product to the treated seeds: temperature of the working compound is 20 to 25 ºС, the pressure in the biopreparation delivery system is 0.4 MPa, the optimal type of spray nozzle is experimental, adapted for working with biopreparations.

The aim of the article is to study the effect of various biological agents of biofungicides on plant resistance to drought and formation of spring barley crops. Endophytic bacteria (Bacillus subtilis), rhizospheric bacteria (Pseudomonas fluorescens), actinomycetes (Streptomyces sp.), and micromycetes (Trichoderma viride) were used as bioagents of biofungicides. Preparations based on biological agents were used to treat spring barley seeds. The studies were carried out in laboratory and field conditions. In the conditions of the model artificial acute drought, it was found that seed treatment with Streptomyces sp. Stimulates the leaf and root growth, as well as increases peroxidase activity in the leaves. The maximum content of proline was during seed treatment with Pseudomonas fluorescens. An increase in the content of chlorophyll was observed when treating with Trichoderma viride seeds. In the field conditions, Pseudomonas putida and Streptomyces were more efficient by the content of proline in seedlings. In terms of the spring barley yield, seed treatment with Streptomyces sp., Pseudomonas putida and Bacillus subtilis was more efficient. Streptomyces sp., Pseudomonas putida and Bacillus subtilis are promising for increasing barley resistance to drought.

The aim of the study was to investigate the peculiarities of microbiome and seed bacterial endophytes isolated from different varieties of spring wheat grown in different areas of Eurasia (European part of Russia (Volga region), countries of Central Asia). The main method of the microbiome studies was PCR. Isolation of bacterial endophytes from the seeds allowed estimating their count and evaluating their activity towards Fusarium oxysporum. Quantitative analysis of the microbiome was performed on seeds from different spring wheat varieties (genotypes) obtained from the Russian Federation, the Republic of Kazakhstan and the Republic of Tadzhikistan. The differences in the bacterial endophytic microflora of the seeds and their activity towards Fusarium oxysporum were established. The seeds grown in Central Asia have higher count of both total microbiome and bacterial endophytes active against phytopathogens than the seeds grown in Volga region of the Russian Federation. Differences in the species composition of seed endophytic bacteria were established. Active strains of seed endophytic bacteria obtained from Tajikistan belonged to the species Bacillus jeuvensis. Active strains of bacterial endophytes were isolated from spring wheat seeds grown in Tadzhikistan for the development of highly potential biofungicides. The study results confirmed that seed microbiome depends on variety and the area of cultivation. The materials of the study can be useful for the evaluation of the seeds in the breeding of spring wheat and in the search for new biological agents for biofungicides development.

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