Effect of Sowing Time and Density on Yield and Yield Components of Direct-seeding Rapeseed

Huayouza 9 and huashuang 5 were used to study the effect of sowing date and plant density on direct seeding rapeseed traits and yield components.The results showed that variety,sowing date and interaction of sowing time and density significantly affected yield.The yield of Huayouza 9 was larger than huashuang 5,mainly due to the increase of effective pods per plant.Early sowing was conducive to individual growth of direct-seeding rape before winter;the number of branches per plant,effective pod number per plant,seed number per pod and 1 000 grain weight all increased.The optimum sowing density differed according to differennt sowing time.Low density could help inspiring yield increasing potential under early sowing conditions;while high sowing density was suitable for late sowing time.