Separation of switchgrass seeds by aerodynamic properties as a way of quality improvement

The article presents the research results on the effect of seed separation (by aerodynamic properties) regime on germination energy and germination in order to reduce the biological dormancy of seeds and significantly improve the quality. Methods. Laboratory, measuring and weighing, mathematical and statistical. Results. With speed increasing in the aspiration column channel from 2.5 to 5.2 m/sec there was a slight change in the 1000-seed weight. There was not dependency in increase in the 1000-seed weight along with increasing air velocity.  Thus, if in the control the 1000-seed weight was 1.65 g, then at the maximum 5.2 m/sec air velocity in the aspiration channel it was 1.68 g (SSD0.05 = 0.10 g).  Germination energy and seed germination significantly increased in all separation modes except for the mode with 2.50 m/sec air velocity in the aspiration channel. The 1000-seed weight that fell into the waste naturally increased with increasing air velocity in the aspiration channel from 0.15 g to 0.40 g, and germination energy and seed similarity were at the level of 0−1%. Increasing the air speed to 7.87 m/sec provided a significant increase in seed germination energy and germination compared to the control and sorting of seeds at an air speed of 5.6 m/sec and 7.49 m/sec, and waste losses in waste increased by 28.0%. Conclusions. Separation of switchgrass seeds of different years of vegetation, collected from panicles of different tiers and maturation dates provided a significant increase in its germination energy and germination and can be introduced into production but it does not completely solve the problem of reducing the biological dormancy of seeds.