Field management
Zhongshuang 11, an elite conventional cultivar with high
pod shattering resistance, logging resistance and high oil
content (49.04%), was employed. Seeds were sown on
September 23, 2009 and October 5, 2010 with a sowing
machine (2BFQ-6, made in Wuhan, China), and the seeding
rate was 2.25 kg ha-1 with planting density of 375 000 plants
ha-1. Chemical fertilizer (525 kg ha-1) containing urea (46%),
super-phosphate calcium (16% P2O5), potassium chloride
(60% K2O), and borax (58.6% B) were applied before
sowing. The herbicide acetochlor (10%) was used to prevent
weeds after sowing. At seedling stage, aphids and
cabbage worm were killed with spraying 10% imidacloprid.
At blooming period, Sclerotinia was prevented with spraying
40% dimethachlon.