Zavalypich N. Formation of winter barley grain productivity depending on growing conditions in the Northern Steppe of Ukraine

The research aim is to study the reaction of winter barley plants to sowing dates and sowing rates, to study the peculiarities of barley productive potential formation in the northern steppe of Ukraine depending on the studied factors. To achieve the aim it was planned to solve the following tasks: to establish the growth and development peculiarities for winter barley plants depending on sowing date and seeding rates; to study the researched factors influence on leaf surface areaformation, photosynthetic potential in different development phases; to study the soil water regime; to identify the peculiarities of soluble carbohydrates accumulation and consumption, plants winter hardiness; to study sowing dates and sowing rates influence on the formation of crop structure elements for winter barley plants; to identify the productivity structural elements influence on the formation of winter barley yield depending on the studied factors; to study yield and grain quality of winter barley depending on sowing dates and seeding rates when sown after sunflower; to determine the efficiency economic evaluation of growing winter barley for grain depending on the studied elements of technology. Scientific novelty of the obtained results. For the first time in the conditions of the Northern Steppe of Ukraine different winter barley sowing dates after sunflower predecessor were investigated and the influence of different standing density of plants on their growth and development was studied. The influence of the studied factors on the photosynthetic potential of winter barley has been established. The optimal parameters of cultivation technology techniques, which ensure maximum winter barley grain yield, have been identified. The economic efficiency of growing winter barley at different sowing dates and sowing rates after sunflower has been determined. The practical significance of the obtained results. According to the research results, the optimal parameters of winter barley cultivation technology were established and recommended for production, they contribute to fuller realization of its genetic potential in the Northern Steppe of Ukraine and provide grain yield over 5.10 t/ha with profitability level of 114.3 %. Key words: winter barley, sowing dates, sowing rates, winter hardiness, grain yield and quality, economic efficiency. Field – agricultural science and food supply.