Perfection of agricultural technologies of oil flax varieties on leached and typical chernozems

Studying of influence of seed sowing dates and seed sowing rates on yield of oil flax varieties bred at VNIIMK (VNIIMK 620 and Nilin), the Siberian experimental station (Severny), and the Don experimen-tal station (Raduga) was conducted at VNIIMK (Krasnodar) on leached chernozem in conditions of unstable moistening and at the Don experimental station by Zhdanov L.A. of VNIIMK (settl. Oporny, Azov district, Rostov region) on typical chernozem in conditions of insufficient moistening, in three-factor field trials in 2015-2016. Seed yield of oil flax varieties appeared to be significantly higher (on 0.21- 1.04 t per ha) when planting on April 1-20 compared to planting on 21-30 of April in conditions of unstable moistening; in conditions of insufficient moistening this increase was only 0.03-0.42 t per ha. The highest yield of oil flax varieties on leached cher-nozem in 2015 was recorded at sowing rate 8 mln seeds per ha, and in 2016 - at 6 and 8 mln seeds per ha. In Rostov region oil flax yield was similar at the different sowing rates in 2015, but in 2016 the highest yield was reached at sowing rate 8 mln seeds per ha. The variety VNIIMK 620 showed the best results on yield in conditions of Krasnodar region, it exceeded the other varieties on 0.18-0.63 t per ha. In Rostov region the variety Raduga had the highest yield (on 0.09-0.27 t per ha higher) in 2015, and the variety Severny (on 0.10-0.64 t per ha) in 2016. The variety VNIIMK 620 had the highest oil content in seeds: in Krasnodar region it was 44.0-46.2% and in Rostov region - 48.9-49.5%. Oil yield was much more higher (on 20-91%) at flax planting in first sowing date. The most productive varieties on oil yield were VNIIMK 620 (on 0.10-0.31 t per ha) in Krasnodar region, and VNIIMK 620 and Raduga (on 0.07- 0.29 t per ha) in Rostov region. Thus, the studied varieties of oil flax in conditions of the south of Russia should be planted not later than on 10-21 of April with sowing rate 8 mln seeds per ha.