Plant and Soil Science

Results of research, aimed at studying effect of various sowing regulations on productivity formation of sowings of investigated sunflower hybrids are presented. Studies were conducted during 2014-2016 in conditions of the Steppe of Ukraine on typical low-humus chernozems. Task o research was to identify influence of such agrotechnical methods as time of sowing and width between rows, productive moisture in a meter-thick layer of soil, water consumption by plants of studied hybrids on formation 1 ton of dry matter and 1 ton of seeds. In result of research was found that reserves of productive moisture at period of sowing were determined, both by sowing dates and weather features of the year of research. More provided by moisture, regardless of sowing time, was 2015, with indicators that were: early sowing time - 146.0 mm, recommended - 134.0 mm, late - 132.0 mm. A close correlation was established between yield and reserves of productive moisture in a meter-long layer of soil at sowing period with a correlation coefficient r = 0.89. The level of total water consumption was determined by moisture conditions before sowing and during the growing season of sunflower and amounted 2977-3893 m³/ha in 2014, 2500-2737 m³/ha in 2015, and 2798-4259 m³/ha in 2016. On average, over the years of research, hybrids differed a little by the total water consumption. On average, over the years of research, sunflower hybrids spent on formation 1 ton of dry matter from 424 to 705 m3/t of water. Clear dependencies in obtained results were not revealed either for influence of sowing dates, or for influence of width between rows.

sunflower, sowing time, row spacing, hybrids, productive moisture, water consumption ratio.