Wheat is the main agricultural crop in many countries of the world, as well as the main food in the steppe zone, so the system of agrotechnical measures should be aimed at creating favourable conditions for obtaining a high yield. The issue of intensification of grain production is inseparable from the production and use of new biogenic effective drugs that have a positive effect on the growth and development of cultivated plants. The purpose of this study was to establish the effect of foliar fertilisation with bacterial preparations, precursors, and doses of mineral fertilisers on grain yield and productivity elements of winter wheat. The paper provides data on the results of the research of winter wheat of the Duma Odeska variety in the conditions of the Educational and Practical Centre of the Mykolaiv NAU in 2019–2021. During the study, generally accepted methods were used: monographic, systematic approach and systematic analysis, analysis and synthesis, field and statistical. The influence of the precursor, foliar feeding with modern bacterial biopreparations and the use of different doses of mineral fertilisers on the elements of the crop structure and grain yield of winter wheat was analysed. It was established that the yield level depended and changed on the precursor taken for foliar feeding of the bacterial preparation, the level of mineral nutrition and to a large extent on the influence of the weather conditions of the growing year. Over the years of research, precursors, mineral fertilisers, and treatment of plant sowing with biological preparations affected the number of productive stems, the number of grains from an ear, the mass of grain from one ear and the mass of 1,000 grains of winter wheat. The conducted studies confirmed the expediency of foliar fertilising in the main periods of vegetation with biological preparations to optimise the nutrition of winter wheat plants with the aim of forming a stable grain yield. The obtained scientific results of the research will contribute to the wide application of biological preparations, which will ensure the rapid and full growth and development of winter wheat plants, which will further contribute to increasing the yield and gross harvest of grain.

Winter wheat is one of the main food crops that ensures the national food security of Ukraine with general production and high-quality grain. The area of winter wheat sowing ranks first in Ukraine, and the production of high-quality grain is of particular relevance. In the technology of its cultivation, the selection of varieties is a decisive factor in increasing yield and improving the quality of grain. The purpose of this study was to determine the influence of weather conditions and variety characteristics during the year on plant height, lodging resistance, and yield of winter wheat. This paper presents data on the results of the research of 20 varieties of soft winter wheat in the conditions of the Research-to-Practice Centre of the Mykolaiv National Agrarian University from 2017 to 2022. During the study, generally accepted methods were used: system approach, system analysis, analysis and synthesis, field and statistical method. The study also analysed the influence of variety characteristics and weather conditions in the years under study on the yield of soft winter wheat. It was established that the optimal plant height of winter wheat varieties ranged within 94.9-100.7 cm, at which the highest grain yield is formed, from 7.09 t/ha in the Staleva variety to 7.73 t/ha in the Duma Odeska variety. An increase in the height of the winter wheat varieties under study by 4.0-6.4% led to a decrease in yield from 4.5 to 20.9%. It was established that the awned varieties of soft winter wheat formed a higher grain yield, compared to the thornless forms, which had a higher plant height and less lodging resistance. The conducted studies confirmed that, on average, the resistance to lodging was higher in the thornless forms of winter wheat plants, which is 0.4 points higher than in the awned ones. The higher average grain yield of soft winter wheat was formed by varieties of spiny forms, which is 5.8% more than that of awned varieties. The obtained results will contribute to the wide application of the varieties of soft winter wheat under study for this soil and climate zone, which will further contribute to the increase in yield and gross grain harvests.

Winter wheat is the main food crop in the Steppe zone and the main agricultural crop in many countries of the world. The issues of intensifying grain production are inseparable from the production and use of new effective biological products for pre-sowing seed treatment, which positively affect the growth and development of winter wheat plants. The purpose of the study was to establish the effect of seed treatment before sowing with biological products on the productivity of winter wheat varieties. The study presents data on the results of an examination of 10 varieties of winter wheat for seed treatment with biological products in the conditions of the Educational and Scientific Practical Centre of the Mykolaiv National Agrarian University from 2020 to 2022. In the course of the study, generally accepted methods were used: system approach and system analysis, analysis and synthesis, field, and statistical. The influence of seed treatment with biological products and varietal characteristics of winter wheat on productivity was analysed. It was determined that the yield level depended and varied depending on the biological product used for pre-sowing seed treatment and the examined variety. Over the years of the study, biological products have affected the Winter wheat is the main food crop in the Steppe zone and the main agricultural crop in many countries of the world. The issues of intensifying grain production are inseparable from the production and use of new effective biological products for pre-sowing seed treatment, which positively affect the growth and development of winter wheat plants. The purpose of the study was to establish the effect of seed treatment before sowing with biological products on the productivity of winter wheat varieties. The study presents data on the results of an examination of 10 varieties of winter wheat for seed treatment with biological products in the conditions of the Educational and Scientific Practical Centre of the Mykolaiv National Agrarian University from 2020 to 2022. In the course of the study, generally accepted methods were used: system approach and system analysis, analysis and synthesis, field, and statistical. The influence of seed treatment with biological products and varietal characteristics of winter wheat on productivity was analysed. It was determined that the yield level depended and varied depending on the biological product used for pre-sowing seed treatment and the examined variety. Over the years of the study, biological products have affected the

The autumn growth and development of plants depend on a complex of external factors: the average daily air temperature, the amount of precipitation, the humidity of the seed layer of the soil, nutrients, light, etc. If winter wheat is sown at a later date, there are risks that the plants will enter the winter not well developed. It is possible to accelerate the passage of interphase periods with the help of irrigation, which is a necessary agrotechnical measure in the Southern Steppe of Ukraine. The purpose of the research is to establish the influence of varietal characteristics, irrigation and weather conditions on the duration of interphase periods of winter wheat in the autumn period on an international scale. Experimental research was carried out during 2020-2021 on southern chernozem, on the basis of the Educational Scientific and Practical Center of the Mykolaiv NAU with two varieties of winter wheat. Field, laboratory and comparative calculation methods were used during the research. The establishment and conduct of experiments were carried out according to the methodology of the research case. Soil moisture was determined by the thermogravimetric method, and phenophases were determined simultaneously throughout the experiment. It was determined that irrigation for 1-2 days reduces the duration of the interphase period of BBCH 00-09; for 3 days – BBCH 10-12; for 11 days – BBCH 13-19; for 5-7 days – BBCH 20-22. In natural conditions (without irrigation), the duration of the interphase periods (from BBCH 00-09 to 20-22) of the growth and development of plants of the studied varieties of winter wheat in 2020 was 93-96 days, which is 23-25 days more than in 2021. In plants of the Ovid variety under conditions of natural moisture (without irrigation), the interphase periods came 1-3 days later than in the Duma Odeska variety, while under irrigation conditions there was no significant difference. The obtained scientific results of the research will contribute to the wider implementation of irrigation, which will ensure the rapid and full growth and development of winter wheat plants in the autumn period, which will further contribute to increasing the yield and gross harvest of grain