Abstract:

In order to explore the effects of sowing date and sowing rate on the agronomic traits and yield of winter rapeseed, provide scientific basis for the production of winter rapeseed in central and southern Hebei Province, the effects of two factors on the growth period, population density formation, agronomic traits and yield of winter oilseed rape were analyzed. Using ‘Tianyou 1358’ and ‘Hengyou 8’ as materials, a two-factor split plot experiment with 5 sowing dates and 4 sowing rates was carried out. The results showed that with the delay of sowing date, the seedling density and branch height of winter rapeseed increased significantly, and the wintering rate, plant height, the number of primary effective branches, the number of effective pods per plant, 1000-seed weight and yield decreased significantly. With the increase of sowing rate, the seedling density and branch height of winter rapeseed increased significantly, the plant height, the number of effective pods per plant and the wintering rate decreased significantly, the number of primary effective branches, the number of seeds per pod and the 1000-seed weight did not change significantly, and the yield increased first and then decreased. The regeneration period of the same variety was the same, but with the delay of sowing date, the budding stage, the early flowering stage and the full flowering stage were also postponed and more obvious, and the final flowering stage and the maturity stage were postponed but the delay time was reduced. The yield of 'Tianyou 1358' and 'Hengyou 8' was the highest when the sowing rate was 6 kg/hm² and 4.5 kg/hm², respectively, and the corresponding sowing date was September 10th. The suitable sowing date in Shijiazhuang area is September 10th to 30th, and early sowing should be carried out if the stubble is allowed. The sowing rate should be controlled at 4.5-6 kg/hm². The reasonable cultivation techniques were summarized in order to provide scientific basis for winter rapeseed production in central and southern Hebei.

Key words: winter rapeseed, sowing date, seeding rate, agronomic traits, yield, Shijiazhuang area