朝阳地区是新麦区,七十年代以后,冬麦的播种面积和种植范围不断扩大。但在冬麦生产中存在的突出问题是麦苗越冬死亡严重。特别是1976—1977年的冬麦越冬死亡面积达50—70%以上。对冬麦越冬大面积死亡原因和死亡时间说法不一,归纳起来有以下几种观点:有的说是“倒春寒”造成的;有 Chaoyang area is a new wheat area, seventy time later, winter wheat sown area and growing range. However, the prominent problem existing in the production of winter wheat is the serious death of wheat seedlings during the winter. In particular, winter wheat winter 1976-1977 over 50-70% of the death area. Winter wheat winter over large area of ​​death causes and death time, different, summed up the following points: Some say is “late spring” caused; there