The article shows the economically valuable features the spring barley and analyzes the most relevant varieties for growing on the farm. It is studied that many varieties of the spring barley with competitive genetic potential of productivity have been created in Ukraine, which in 2021 makes 181 varieties. It is shown that the use the best varieties and high quality  seeds is one the most effective means of economic growth in the agro-industrial sector. In recent years, there has been an increase in the spread various diseases of plants spring barley, leading to significant yield losses. We analyzed modern methods of plant selection which allows faster searching new markers with partial resistance to diseases. It is shown that one the strategic direction of modern agriculture development is its biologization — the use of biological means to obtain quality products crop and the reproduction of fertility soils. Modern views on the effective use of biological preparations of different spectrum of action in the technologies of growing crops were presented. It is established that the use ecologycally safe technologies for growing spring barley is relevant. This does not only increase resistance to adverse conditions and phytopathogens, but increases yields and improves grain quality. We analyzed liquid microfertilizer Oracle and complex natural-synthetic preparation Vimpel 2, products of Dolyna company. These preparations have an inhibitory effect on plant diseases and building stimuli of natural plant immunity. Analysis of scientific and technical literature allows us to conclude that the urgent task is to find ways to regulate phytopathogenic microorganisms to ensure the harmonious flow of biological processes in the soil, improve plant nutrition, and the formation of full-fledged plant-microbial associations, which allows controlling the development and spread of pathogens.

One of the important factors in obtaining quality seeds of cereals is the technology of cultivation, which should ensure high yields and quality of grain and be safe for the environment. Therefore, the aim of our study was to determine the impact of different growing technologies on the pathogenic microflora of the seeds winter wheat and oats. It was established that on the seeds of winter wheat of the variety Oberig Myronivskyi according to the traditional growing technology 7 genera of phytopathogenic micromycetes parasitized such as Alternaria spp., Fusarium spp., Aspergillus spp., Acremoniella spp., Bipolaris spp., Penicillium spp., Cladosporim spp., which were characterized by different frequency of occurrence from 10% to 60%. On the seeds of oat variety Timbre we identified such phytopathogenic micromycetes as Alternaria spp., Fusarium spp., Aspergillus spp., Chaetomiums spp., Drechslera spp., Penicillium spp., Trichoderma spp., where their frequency of occurrence was from 10 to 50%. The highest frequency of occurrence the seeds winter wheat and oats by traditional growing technologies was characterized by genera Aspergillus spp. and Penicillium spp. This can create a significant problem when storing seeds and suppress its germination. Under organic growing technology on winter wheat seeds of the variety Oberig Myronivskyi micromycetes of the following genera: Alternaria spp., Fusarium spp., Aspergillus spp., Chaetomiums spp., Penicillium spp., Trichoderma spp., Bipolaris spp. were identified, where their frequency of occurrence was from 25 to 50%. On the seeds of oats of the variety Timbre there were micromycetes of genera: Alternaria spp., Fusarium spp., Aspergillus spp., Chaetomiums spp., Drechslera spp., Penicillium spp., Trichoderma spp. with frequency of occurrence from 10 to 50%. The dominant genus was Trichoderma spp. Fungi of this genus have the ability to multiply rapidly, which will compete with other microorganisms. The growing technology of cereal affect not only the number and frequency of occurrence phytopathogenic micromycetes on seeds, but also sporulation and their reproductive structures. It was found that the seeds of winter wheat and oats, in the conditions of traditional growing technology, the similarity of micromycetes was 56%. At the same time, the coefficient similarity of species the phytopathogenic micromycetes on the seeds of the studied crops, in terms of organic technology, was slightly higher and amounted to 63%. The analyzed indicators, such as the frequency of occurrence and the similarity coefficient, make it possible to evaluate the seeds of growing plant varieties in order to avoid biological contamination of agrocenoses with infectious structures of the phytopathogenic micromycetes.

The number phytopathogenic micromycetes is determined in the seeds of such cultivated varieties of cultural plant as soybeans, sunflowers, yellow mustard, buckwheat and thistle, which are grown by organic technology. It is shown that the number of micromycetes in the plant seeds differs significantly and ranges from 0.2 to 1.3 thousand NCO/g seeds. It depends on properties plants variety and hybrid, which are characterized by some certain set of physiological and biochemical characteristics that influences the formation seed mycobiome and it is quantitative composition. In the seeds varieties of these crops we identified such species of the phytopathogenic fungi as Alternaria alternate Fr., Fusarium oxysporum Schleht, Cladosporium herbarum Lket Gray, Botrytiscinerea Pers. Ex Fr., Ascochyta fagopyri Bres., Alternaria tenuissima (Kunze) Wiltshire, Aspergillus P. Micheliex Haller, Pénicillium Link. It was found that the species composition of phytopathogenic micromycetes in the seeds of soybean cultivar Kent and thistle Riches is much more diverse than the seeds other crops dominated by fungi A. alternate and F. oxysporum, which are characterized by different frequency of occurrence. These phytopathogenic fungi can cause plant diseases at different stages of ontogenesis, produce mycotoxins and reduce the quality of plant products. In the mycobiome of seeds buckwheat varieties Sophia, Sуn and sunflower hybrids Oscar and Oliver are dominated by fungi of the genus Pénicillium аnd Aspergillus (60–90%). The seeds affected by saprotrophic fungi can be reinfected during storage. This reduces its field and laboratory germination of the seeds. Saprotrophic fungi that dominate the seeds significantly impair its quality during storage and cause dangerous plant diseases in agrophytocenoses during the cultivation of this variety/hybrid. This requires the application of additional preventive protection measures of plants. Mycobioma mustard seeds of а yellow variety Ford represents a small number the phytopathogenic micromycetes. This may indicate its environmental safety in organic production. Thus, the analyzed research results indicate a significant differentiation in varieties species as to composition and number of phytopathogenic species of micromycetes in the seed mycobioma. Therefore, in order to avoid ecologic risks and biological contamination of agrocenoses, it is necessary to test the seeds, as on the density of the mycobiome and on the frequency of phytopathogenic micromycetes damage.

Phytopathogenic aggressiveness is the ability of a fungus to reproduce in the tissues of host plants, which is manifested in different growth rates of mycelium, intensity of spore formation, viability of fungal spores, duration of development cycle and its resistance to extreme conditions. Varieties and hybrids of crops have a significant effect on changing the aggressiveness of phytopathogenic micromycetes. Therefore, the aim of the study was to determine the aggressiveness of the fungus Alternaria alternata (Fr.) Keiss under the influence of sunflower hybrids grown in different technologies. The influence of sunflower hybrids on the change of aggression was studied using the methods given in the methodological recommendations of M.O. Lemezi. The aggressiveness of A. alternata under the influence of sunflower hybrids grown by different technologies was analyzed. The following indicators were used for evaluation: viability of phytopathogenic micromycete spores, intensity of its spore formation and score of sunflower seedlings by the studied fungus. And also determined the degree of aggressiveness and pathogenicity of the fungus A. alternata. According to the results of the study, a high dependence of the aggressiveness of the studied micromycete on the biological properties of sunflower hybrids of different breeding origin was established. The Dushko hybrid, compared to the Oliver hybrid, both in traditional and organic cultivation technologies, can significantly reduce the aggressiveness of the phytopathogenic fungus A. alternata. This indicator should be used for ecological research of sunflower hybrids as a factor of biological pollution of the agrocenosis, that will allow to managing the stability of agroecosystems and obtain environmentally friendly and safe crop products.

Soil microbiota is one of the most important factors that determine the formation processes as well as the biological properties of the soil. The use of microbiological preparations in modern technologies not only increases the resistance of plants, productivity, and quality of products, but also contributes to the formation of the microbial complex inherent in each plant. The aim of our study is to determine the number of microorganisms of individual ecological and trophic groups of the rhizosphere soil for spring barley plants depending on the elements of the cultivation technology (application of the preparations). The number of the main ecological and trophic groups of the soil during the ontogenesis of spring barley of Sebastian and Helios varieties changes depending on the elements of cultivation technology (application of the preparations), the phase of ontogenesis, as well as soiland-climate conditions. During the ontogenesis of spring barley plants, the increase in the number of pedotrophic micromycetes was observed. The most of pedotrophic micromycetes was found in the soil were plants of Sebastian and Helios varieties were planted, with the use of Vimpel 2 and the mixture of Vimpel 2 + Oracle multicomplex. This confirms that the soil contains a sufficient amount of organic matter. Also, throughout the vegetation season, the pathogenic mycobiota was characterized by a high number in agrocenoses of spring barley. The variants in which Vympel 2 and mixtures of Vympel 2 + Oracle multicomplex had been used, the number of pathogenic micromycetes in the soil were the spring barley plants were planted decreased significantly. That shows the fact that the preparation Vimpel 2, both individually and in a mixture, is able to protect plants from diseases by improving their immunity. The number of oligotrophic microorganisms was the highest in the control variant, and it was the lowest with the use of all the studied preparation, respectively. The number of humate-forming micromycetes also decreased by 1-1,5 times compared to the one in the control variant. The application of Vimpel 2 and Oracle brought to the situation in which multicomplex significantly intensified the development of ammonification microorganisms. Amylolytic microorganisms and cellulose-destroying micromycetes also increased. These microorganisms degraded cellulose-containing substrates in the presence of enzymes. They don't require a large amount of the nutrients, but thereby provide an opportunity for the development of other micromycetes that absorb hydrolysis products. Therefore, rhizospheric soil under sowing of spring barley plants is able to form a microbial complex that significantly depends on the elements of growing technologies. The confirmed coefficients of mineralization-immobilization nitrogen, pedotrophicity, and oligotrophicity, determined the regularities of the processes of nitrogen mineralization and immobilization as well as the availability of easily digestible organic substances in the soil depending on the elements of culti...