Abstract: Abstract:【Objective】The studies were conducted for studying on feasibility of expanding winter rapeseed northwards into dry,cold regions in Northwest China and screening of the winter type rapeseeds cultivars adaped to this area.【Method】Field experiments were carried out in 2001-2006 at 10 locations in northwest China’s Gansu Province where latitude ranged 35°30’-39°46’N, elevation ranged 1477-2300 m, precipitation ranged 92.0-630 mm, and annual average temperature ranged 5.9-8.7 oC.【Result】The 40 Brassica napus cultivars or breeding lines tested did not survive the local winter. All the 15 B. rapa materials tested, all of which were native of northwest China, had >70% overwintering rates at most locations. At Jiuquan, the northernmost 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 unit land cash return. 【Conclusion】As a winter cover crop, it may eliminate a dust source that furnishes the damaging sand storms in northern 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.

Key words: Winter rapeseed, crop adaptation, cover crop, winter hardiness, northwest China, sand storm