Productivity of oil flax sowings under perfection of the elements of the adaptive technology

Influence of the elements of the adaptive technology (sowing dates and seed sowing rates) on productivity of oil flax varieties bred at All-Russia Research Institute of Oil Crops (VNIIMK 620 and Nilin), the Siberian experimental station (Severny) and Don experimental station (Raduga) were studied in three-factors field trials at VNIIMK (the Krasnodar region) on leached chernozem in a zone of unstable moistening and at Don experimental station (the Rostov region) on common chernozem in a zone of insufficient moistening in 2015-2017. It was determined that seed yield of oil flax were significantly higher in the zone of unstable moistening when sowed at the first date (April 1-20) compared to the second sowing date (April 21-30) - by 0.56 t per ha, and in the zone of insufficient moistening - by 0.23 t per ha. The highest yield were fixed at sowing rate 8 and 10 million seeds per ha on leached chernozem - 1.36 t per ha and common - 1.80 t per ha. The varieties VNIIMK 620 (1.51 t per ha) and Raduga (2.01 t per ha) were the most productive in the conditions of the Krasnodar and Rostov regions, respectively; they exceeded the other varieties by 0.08-0.30 and 0.18-0.47 t per ha, respectively. Oil content in seeds was higher when planted at the first date by 1.6% in the Krasnodar region and by 0.3% in the Rostov region; however, it did not depend on seed sowing rates. The highest oil content in seeds was fixed for the variety VNIIMK 620 - 45.0% in the zone of unstable moistening and 49.8% in the zone of insufficient moistening. Oil yield was significantly higher (by 0.23 t per ha in the Krasnodar region and by 0.11 t per ha in the Rostov region) when flax varieties were planted at the first sowing date. Seed sowing rates did not influence the oil yield. The varieties VNIIMK 620 (0.60 t per ha) in the zone of unstable moistening and Raduga (0.87 t per ha) in the zone of insufficient moistening were the most productive on oil yield. Thus, the studied oil flax varieties in the different soil and climatic conditions of the southern regions of Russia should be planted not later April 20 with sowing rate 8 million seed per ha at production under adaptive technology.