小麦赤霉病在我国分布很广,主要是在多雨潮湿的长江中下游冬麦地区发生。近年来,随着耕作制度的改变,品种的更换和施肥水平的提高,特别是灌溉面积的扩大,此病在一些过去很少发生或不发生的地方如苏北、皖北、陕西的关中,以及山东、山西、河南、甘肃等省的局部地区也有明显的发展趋势。一般每隔3—2年就有一次流行。在流行年份病穗率在50—100％,减产可达10—40％;中度流行年的病穗率在30—50％,减产幅度在5—15％之间。河南省由于轮作制度较为单一,大都是 Wheat head blight is widely distributed in China, mainly in the rainy and wet winter wheat in the middle and lower reaches of the Yangtze River. In recent years, with the change of cultivation system, the change of varieties and the improvement of fertilization level, especially the increase of irrigated area, the disease is rarely seen or occurred in places such as northern Jiangsu, northern Anhui, Shaanxi Guanzhong, As well as Shandong, Shanxi, Henan, Gansu and other provinces in some areas also have obvious trends. Generally every 3 or 2 years there is a popular. In the popular year disease ear rate in 50-100%, cut up to 10-40%; moderate pandemic disease panicle rate in 30-50%, the rate of reduction in the range of 5-15%. Henan Province, because the rotation system is more single, mostly