Abstract: A field experiment was conducted to investigate the effects of different sowing date and planting density on the seed yield and seed oil content of winter oilseed rape (Brassica napus). Sowing date mainly affected the seed yield of branch raceme, while planting density affected the seed yields of both branch raceme and main raceme. The seed oil content was less affected by sowing date. The proportion of the seed yield of main raceme to the seed yield per plant increased with increasing planting density, and the seed oil content of main raceme was about 1% higher than that of branch raceme. Consequently, the seed oil production per plot increased significantly with increasing planting density. In the experimental region, the sowing date of winter oilseed rape should be earlier than midOctober. When sowing in late October, the seed yield would be decreased significantly. A planting density of 36-48 plants·m^-2 could improve the seed yield and oil content of winter oilseed rape.

Key words: winter oilseed rape, sowing date, planting density, seed yield, oil production.