Formation of high-productive agrocenoises of corn and sorghum crops on agro grey soils of Bryansk high plains
The article presents results of studying corn hybrids of different ripening groups and the range of varieties of sorghum crops in agroclimatic conditions of Bryansk region. On average, over the years of variety testing of corn hybrids, the highest yield of normalized dry matter was recorded in crops of midspring hybrid Voronezhsky 279 SV (16,771 / ha) or over 801 / ha of green mass. High-yield hybrids of sorghum such as Porumben 4 and Porumben 5 should be distinguished from the variety of sorghum crops, their yield was more than 15 t/ha of dry matter. The early hybrid Ladozhskiy 181 MV (8,75 t / ha) and hybrids Voronezhskiy 279 SV (8,461 / ha), Voronezhskiy 185 SV (7,05 t / ha) were note for high yield of corn grain; from the group of foreign selection - the hybrid Irondel, the originator is RAGT semences (7,03 t / ha), MAS14.G (7,44 t / ha) - the selection of Maisadour semences, France. The greatest reaction to year conditions had a sorghum hybrid Porumben 5 (b<sub>i</sub> = 1,2) with the most stable increase or decrease of yield (S<sub>i</sub><sup>2</sup> = 5,1). The influence of density and seeding methods on production process of sugar sorghum hybrids (Slavyanskoe Priusadebnoye), sorghum-Sudan hybrid (Kinelskaya 100) and sorghum-Sudan hybrid (Slavyanskoe pole 15 F<sub>1</sub>) was studied. Different reaction of the variety range of feed sorghum to crop overcrowding and application of mineral fertilizers was established. The coefficient of energy efficiency of sorghum feed of exchange energy was 3,7-6,6, it means that there is more energy in biomass than the energy spent for its production. The economic cultivation efficiency of Russian hybrid Ladoga 181 MV for grain was 46,1% higher than that of the hybrid of foreign selection.