近年来春季麦田草害调查时,发现草害重的田小麦纹枯病也较重。1983～1984两年的调查结果,重草田内重病田比例大:总草复盖度>40％的三级草害田10块内,发病率>50％的重病田块占80％;总草复盖度20～40％的二级草害田37块内,重病田占64.7％;总草复盖度<20％的一级草害田内,重病田占47.7％。这主要因为杂草增加 In recent years, investigation of spring wheat field grass weeds found that grass blight wheat sheath blight is also heavier. From 1983 to 1984, the results showed that in the heavy grassland, the proportion of severe diseases in the heavy grassland was large: in the 10 grassland of the third grade grassland with the grass coverage> 40%, the severe diseases with the incidence> 50% accounted for 80% of the total; In the second grade grassland with coverage of 20-40%, 37 seriously ill fields accounted for 64.7% of the total. The first grade of grassland covered less than 20% of total grasslands accounted for 47.7% of seriously ill fields. This is mainly because weeds increase