Inhibition of winter seedling raising in greenhouse of prematurebolting in Angelica sinensis

OBJECTIVE: To study the inhibition effect of winter seedling raising in sunlight-greenhouse on premature bolting of Angelica sinensis. METHOD: One factor of sowing date with 4 levels was tested at random design with 3 repeats. RESULT: Sowing date of winter seedling raising had an important effect on seedling growth, seedling mature, plant growth, premature bolting, yield, quality, and extreme significant effect on yield. The bolting date of winter raised seedlings started in middle of July, 50 d later than tranditional seedlings, and bolting peck date was in the last ten days of July, 40 d later than the traditional seedlings. The highest ratio of premature bolting for winter raised seedlings was 1%, and the lowest was 0. A. sinensis roots sowed in November 28 had the highest yield, root dry ratio, ethanol extract, essential oil and ferulic acid contents compared to that in other sowing dates. The best sowing time was from end of November to middle of December. CONCLUSION: Premature bolting of A. sinensis could be greatly inhibited by winter seedling raising, end of November to middle of December would be the best sowing time for winter seedling raising in greenhouse.