Dytso O. High-quality features of formation of seed production and sowing qualities of seeds of winter rye in the conditions of Forest-Steppe of Western Ukraine

This thesis presents the results of research on the formation of rye seed productive properties and sowing qualities in the Western Forest Steppe of Ukraine, which belongs to the zone of risky grain crops seed production. It was found that, depending on the biological characteristics, varieties exhibit different reaction to soil and climatic conditions of cultivation, which causes difference in their productivity. The highest coefficient of photosynthesis efficiency in the XI-VII stages of organogenesis and plant resistance to powdery mildew, leaves septariose, dark-brown rust, Septorios and Fusarios of ear was observed in varieties Knyazhe, Siverske, Veliten, Zabava. From 12 studied varietis the highest seed yield provided Veliten - 4,75 t/ha; Knyazhe - 4,62; Zabava - 4,57; Siverske - 4,39 t/ha. The strength of the varietis effect on productivity was - 29 %, the weather conditions - 39 %, their interaction - 27 %, other factors - 5 %. The yield of conditioned seeds in all varieties exceeded 70 %. The process of seeds formation held by laws specific to forest-steppe ecological type varieties. Compared with the phase of full ripeness mass of 1000 seeds "on the vine" 4 days was 2,2 g (6,0 %) 8 days - 3,2 g (8,8 %), 12 days - 4,8 g (13,2 %). The sowing qualities indicators of collected seeds were high, both in years of research and on varieties, respectively: germination - 80-82%, laboratory germination - 92-94 %. Genetically implicit weight of 1000 seeds ranged at 0,4-2,8 g under the influence of external factors and depending on the characteristics of varieties ranged from 35,7 to 38,5. The output of the coarse fraction of seeds (2,2-2,5 mm) in grades ranged from 51,9 to 56,7 %, medium (2,0-2,2 mm) - from 23,4 to 28,1%, and the small (1,7-2,0 mm) - 15,2 to 23,5 %. A high percentage of the output of large and middle fractions observed in varieties Veliten - 56,7 and 28,1 %, Knyazhe - 55,9 and 27,7 %, Siverske - 54,8 and 26,5 %, Zabava - 55,1 and 26,8 %. The highest seed productivity and sowing qualities of seeds provided varieties on resource-saving technology of winter rye cultivation.