1981年淮北地区北部,自4月底小麦开花到5月底灌浆结束期间,连续出现19天6—7级干热风的侵袭,占这个时期总日数的61.3％,致使小麦受到严重危害,减产甚大。这一年,我们对受干热风危害后小麦的生理变化和各项防御措施的效果作了一些调查,现综合整理如下。一、小麦受害后植株的生理变化 (一)开花高峰期转移,花期缩短,小花败育率增多。据我们对泰山1号的观察,小麦开花期由于干热风的影响,上午开花量只占 In the northern part of Huaibei in 1981, since the wheat flowering from the end of April to the end of filling of the end of May, 19 successive dry-hot winds of grade 6-7 hit consecutively, accounting for 61.3% of the total number of days in this period, resulting in severe damage to wheat and a great yield reduction. During the year, we made some investigations on the physiological changes of wheat and the effects of various defensive measures after it was harmed by hot and dry winds. First, the physiological changes of plants after wheat damage (A) flowering peak flowering, flowering shortened, abortion increased. According to our observations on the Taishan 1, the flowering of wheat due to the impact of hot and dry wind, flowering in the morning accounted for only