[Responses of winter wheat growth to winter warming in Gansu Province].

Based on the observation data of the air temperature at Tianshui and Xifeng in 1951-2005 and of the phenology of winter wheat at Tianshui and Xifeng in 1981-2003, the tendency of winter warming in past 50 years and the responses of winter wheat growth to climate warming in Gansu Province were analyzed. The results showed that the growth and development of winter wheat were seriously influenced by winter warming. In recent 20 years or more, the overwintering mortality of winter wheat dropped to <2% , overwintering days reduced by 7-8 days, whole growth period shorted by 8-10 days, and jointing-flowering period extended by 7 days, which would benefit the production of winter wheat and the utilization of climatic resource. However, the higher winter temperature and lesser precipitation also made the grain yield instable and the plant diseases and insect pests more frequent, resulting in more uncertain factors in winter wheat safe production.