Lately, the organic cereals field has been progressively developing. A limitation of conventional untreated seed application plays an important role there. On the other hand, there has been a longtime deficiency of certified organic seeds. Therefore, oat was experimentally used as a model crop in order to demonstrate results of the assessment of particular biological traits of various seed categories (certified organic, conventional untreated, farm). The seeds' biological traits (energy of germination, germination, energy of emergence, emergence, thousand grain weight - TGW) were assessed before seeding and the impact of the seed quality on the grown seeds was also studied. Small-plot trials including four varieties of naked and hulled (common) oat were set up in three localities in the Czech Republic between 2010 and 2011. As for the quality of the seeds serving for the establishment of the small-plot trials, the conventional untreated seeds proved the highest quality for the energy of germination (86.3%), the germination (88.3%), the energy of emergence (72.8%), the emergence (79.1%) and the TGW (31.9 g). On the other hand, as for the organic seeds, these originating from the certified organic crop stands proved the highest quality for the energy of germination (90.4%), the germination (92.6%), the energy of emergence (79.4%), the emergence (85.8%) and the TGW (30.8 g), just as these originating from the farm crop stand the energy of germination (90.2%), the germination (88.3%), the energy of emergence (79.2%), the emergence (85.4%) and the TGW (30.4 g). The energy of germination, the germination and the energy of laboratory emergence were ( p
