玉米丝黑穗病俗称“火烟包”,是一种病原真菌所致的病害。威远县过去无大发生的历史,1978年前后由于从山东、河南、山西等省大量引种而传入。随着病原菌在土壤中的积累和感病品种的扩大种植,病害逐年加重。1981年,全县发病面积达14.5万亩,占玉米种植面积的69％。一般被害株率5％左右 Corn smut commonly known as “fire tobacco package” is a disease caused by pathogenic fungi. Weiyuan County in the past without major history, before and after 1978 due to a large number of introduction from Shandong, Henan, Shanxi and other provinces introduced. With the accumulation of pathogenic bacteria in the soil and the expansion of susceptible varieties of planting, disease is increasing year by year. In 1981, the county incidence of 145000 acres, accounting for 69% of corn acreage. The average victim strain rate of about 5%