The aim of this study was to evaluate the physiological potential of seeds of white

oat cultivars grown at different sowing dates and densities. Two independent experiments were

conducted with two different sowing dates in a randomized block experimental design in a 4 × 2

factorial arrangement, with four replications. The treatments consisted of four sowing densities

(180, 240, 300, and 360 viable seed.m-2) and two cultivars (IPR Afrodite and IPR Artemis).

The following evaluations were made: thousand seed weight, germination percentage, first

germination count, seedling length, seedling dry matter, emergence speed index, and seedling

emergence in sand. Joint analysis of variance was carried out on the data regarding sowing dates

separately for the cultivars. The mean values for sowing dates were compared by the F test;

and polynomial regression analysis up to the second degree at 5% probability was conducted

on the densities. The seeds produced by the plants grown from the first sowing date had better

vigor than those produced by plants from the later sowing date. The increase in sowing density

reduces the weight and vigor of the seeds produced by plants from the second sowing date. For

the IPR Afrodite and IPR Artemis cultivars, the use of 180 seed.m-2 in the first growing period

allows production of seeds with greater physiological potential.