冻害是由于温度过低所引起的对作物的伤害现象。遭受冻害的程度与降温强度、低温持续时间的长短和作物忍耐低温的能力有密切的关系。成都地区冬季温度较高(最冷月平均气温5℃以上),小麦一般都不停止生长,冻害亦不多见。但若提前播种,过早拔节(小麦拔节后的耐寒力大大减弱),一旦低温来临,就易遭 Frost damage is caused by the temperature is too low on the phenomenon of crop injury. The degree of frost damage is closely related to the intensity of the temperature drop, the duration of the low temperature and the ability of the crop to tolerate the low temperature. Chengdu winter temperatures are higher (the coldest month average temperature of 5 degrees Celsius), wheat generally do not stop growing, frost damage is rare. However, if the early sowing, premature jointing (cold weakened wheat jointing greatly weakened), once the cold, it is easy to suffer