Nosov S. Optimization of technological measures of grain corn growing in the conditions of Northern Steppe of Ukraine

Object of study – the growth, development and formation of grain yield of modern corn hybrids of different groups of repeness depending on the application of optimized technological methods of their growing – sowing times, plant densities, herbicides. Purpose – optimization the certain technological measures of growing of modern corn hybrids of different groups of repeness – the early-ripening hybrid Pochaivskyi 190 MV, the middle-early hybrid Yarovets 243 MV, the middle-repening hybrid Krasyliv 327 MV and the middle-late repening hybrid Bystrytsia 400 MV in the conditions of the Northern Steppe of Ukraine. Methods – field, augmented with the visual and measuring and weighting method to determine the duration of interphase periods of corn plants development, species and weights of weeds, as well as plant density, crop productivity and crop structure; analytical – to determine the chemical composition of production; mathematical and statistical – to assess the reliability of the data; calculated method - to determine the economic and bioenergy efficiency of technological methods. Results: the technological measures of corn grain growing for the production are recommended, that provide obtainment of corn grain yield 3,43–4,62 t/ha with the level of profitability 42,8–88,5 %. The results of research have been introduced into production on the territory of limited liability company Agrofirm "Obrii", Pokrovskyi district, Dnipropetrovsk region on the area of 221 hectares. The use of the proposed measures of growing technology provided to obtain grain yield 3,92 t/ha with the profitability of grain production 59,2 %. Novelty – for the first time optimum parameters of preharvesting density of planting for corn modern hybrids of different ripeness groups are determined – early-ripening Pochaivskyi 190 MV, middle-early ripening Yarovets 243 MV, middle-ripening Krasyliv 327 MV, middle-late ripening Bystrytsia 400 MV; improved protection from weeds of corn sowings with application of soil-applied and postemergence herbicides under different sowing times; has got the further development peculiarities of growth, development and formation of productivity and quality of grain of corn hybrids depending on factors to be investigated. Sector – agricultural science.