A simplified cultivation technique of rapeseed grownin triple cropping system paddy fieldsⅡ. Effects of sowing dates, cultivars, sowing rates and sowing patterns on broadcastsowed rapeseed in notillage paddy fields

Chen Sheyuan Guan Chunyun Wang Guohuai(Oil Crops Research Institute, Hunan Agric. Univ., Changsha 410128)

Notillage paddy field Rapeseed Broadcastsowing

The rapeseed seeds were broadcastsowed in the notillage paddy field immediately after the late rice was harvested. The effects of cultivars, sowing dates, sowing rates and sowing patterns on the yield and growth of rapeseed were studied. The results indicated that the rate of emergence was about 90%, 80% or so of seedlings developed into the plants which produced the siliques, the plants were about 70% tall and had 65% of leaves compared with the transplanted plants, average prewinter leaf area coefficient for broadcastsowing was 1.6 greater than that for transplanting, there were more siliques per area, less branches per plant and less seeds per silique under the condition of broadcastsowing, the yield of broadcast sowed rapeseed reached 1200kg/hm2 and mainly affected was sowed later, yielded less than transplanted rapeseed, but matured earlier and 3～4 times higher in economic profit.