玉米大斑病是玉米的主要叶部病害,可以流行成灾。在我国,最早的报导是1888年在东北发生,之后在华南、西南、中部各省曾多次发生。建国后先后在河南、河北、山东、辽宁、吉林、黑龙江、山西、陕西、甘肃及四川、云南、广西等省的玉米产区严重发生。病害严重发生年份一般减产15—30％,重病区可减产50％左右。我省属玉米大斑病发生区,该病对我省玉米生产威胁很大。为摸清其发生及流行规律, Maize leaf spot is the main leaf disease of corn, can be epidemic. The earliest reports in our country took place in the northeast in 1888, and then many times in south China, southwest and central provinces. After the founding of new China, maize production in Henan, Hebei, Shandong, Liaoning, Jilin, Heilongjiang, Shanxi, Shaanxi, Gansu and Sichuan, Yunnan and Guangxi provinces occurred seriously. A serious disease occurred in the general reduction of 15-30% of the year, severe disease reduction of about 50%. My province is a spotted area of ​​corn blight, the disease is threatening the corn production in our province. To find out its occurrence and prevalence laws,