Studies on feasibility of expanding winter rapeseed northwards into dry, cold regions in Northwest China

摘要

Field experiments were carried out in 2001-2006 at 10 locations in Gansu Province, the Northwest China, where the latitude ranged from 35°30' to 39°46'N, the elevation ranged from 1477 to 2300m, the precipitation ranged 92.0-630mm, and the annual average temperature ranged 5.9-8.7 °C. Forty The 40 cultivars/lines of Brassica napus tested could not survive the local winter. All 15 B. rapa materials tested, all of which were native of Northwest China, had the overwintering rates ＞70% at most locations. At Jiuquan, the northemmost location, only the ultra winter-hardy lines MXW-1 and DQW-1 survived the winter. The B. rapa winter rapeseed had desirable agronomic characteristics and outyielded spring rapeseed and flax. Its early maturity maximized the multiple crop index and increased unitland cash return.As a winter cover crop, it might eliminate a dust source that furnished the damaging sand storms in northem China. It is not only possible but also beneficial economically, environmentally and ecologically to grow winter rapeseed in the dried and cold regions in Northwest China.