INFLUENCE OF SOWING TERMS AND SEEDING RATE ON PRODUCTIVITY OF OIL-BEARING FLAX

It represents the results of the research on the influence of sowing time and sowing rate on the yields of oil flax intended for dual purpose. On the basis of the analysis of the yield and quality indexes, the study substantiated the value of the straw as a source of fiber raw material and the expediency of dual purpose of oil flax. It was proved that the shift of the crop sowing time for 10 and 20 days of the time when the soil has acquired the state of physical maturity, caused a decrease in the seed yields by 1.9 and 14.6%, and the straw yields – by 3.9 and 19.5%. It was established that the sowing rate of 6 million pieces per hectare maintains the highest seed yield of 1.3-1.34 tons per hectare, and the straw yield of 1.65-1.75 tons per hectare. In order to obtain the seed maximum yield under late sowing time, the sowing rate should be increased to 8 million pieces per hectare. When the time of sowing flax is shifted, there is a reduction of bast content, the general and technical length of the stem and its diameter. Regardless of the crop sowing time, an increase in the sowing rate is accompanied by an increase in bast content within 0.8 to 1.1 points, the technical stem length – within 17.7 to 23.6%, an increase in the stem strength – from 1.5 to 3 kgf, and a reduction of its diameter – from 0.61 to 0.78 mm. It was established that the shift of the sowing time of the time when the soil has acquired the state of physical maturity for more than 10 days has the most negative influence on the seed and straw yields and physical and mechanical properties of the stems. Using the results of the regressive analysis, mathematical models of the influence of the crop densification on the yield and bast content in the straw for different sowing times were proposed. The results of the research show that the sowing rate should be increased to 8 million pieces per hectare