To address the issue of increasing the sowing qualities of seeds and reducing their injury during post-harvest processing, a prototype of the universal dryer US-0.35 was designed, manufactured, and tested. A new energy-efficient three-stage convective drying method has been implemented in the dryer. The author carried out a series of the laboratory and field experiments on the effect of the developed method of drying on the sowing qualities of seeds using the example of winter rye, spring wheat, and spring oats. The experiments allowed determining germination, the germination energy of seeds and the completeness of sprouts. Before the start of the experiment, each crop was harvested by a combine harvester DON-1500B, carefully adjusted according to the manufacturer instructions. The combine straw walker keys were upgraded with flexible pads. Reference samples of grain crops were dried according to the standard technology, by the convective method with the SKU-2.5 dryer. The experimental samples were dried with the developed universal dryer US -0.35. It has been shown that the output of experimental rye seeds stockpiled for storage was 12.5% more as compared to the reference group. The output of experimental wheat seeds was 11.7% more as compared to the reference group. The output of experimental oats in the group was 4.6% higher as compared to the reference group. The seed germination rates of rye, wheat and oats exceeded those of the reference group, respectively by 7.6, 5.4, and 4.2%, and the germination rates, respectively, by 15.1, 19.5, and 4.2%. The field experiment results have shown that the completeness of rye sprouts from the experimental group was 12.5% higher as compared with the reference group, while wheat and oats were significantly higher by 10.1%.