70年代以前,小麦叶枯病只在河南省部分地区偶尔发生。1979—1985年我省引种春播小麦,根腐叶枯在春小麦上普遍发生,引起严重的叶枯和穗腐,减产一般在30％以上。1990年河南省小麦叶枯病发生650万亩,仅尉氏县西部沙丘陵发生11万亩,产量损失平均30—40％。1991年全省发生此病1000多万亩,其中周口、商丘、驻马店和南阳地区的发生面积均在100万亩以上。小麦叶枯病成为严 Before the 1970s, wheat leaf blight occurred only occasionally in parts of Henan Province. Spring introduced wheat from 1979 to 1985 in our province. Root rot rot occurred on spring wheat and caused serious leaf blight and spike rot. The yield was generally above 30%. In 1990, 65 million mu of wheat leaf blight occurred in Henan Province. Only 110,000 mu of sand dune hills in the west of Weishi County occurred. The average yield loss was 30-40%. In 1991, more than 10 million mu of this disease occurred in the province, of which, Zhoukou, Shangqiu, Zhumadian and Nanyang occurred in an area of ​​over 1 million mu. Wheat leaf blight becomes strict