近年来,随着秸秆还田年限的增加,玉米褐斑病有加重趋势。特别是夏玉米感病高峰期基本与夏季雨热同步,有利于褐斑病发生,病株光合作用差,导致结穗小、产量低、品质差。褐斑病发生在玉米生长中后期,在喇叭口期始见病,抽穗期至乳熟期集中显症。主要危害叶片,也危害叶鞘及茎秆。症状首先表现在顶部叶片的尖端,最初出现黄褐色圆形或椭圆形斑点,病斑常汇集沿叶脉形成条斑,多个条斑形成横向病斑 In recent years, with the increase of straw returning years, maize leaf spot is aggravating. In particular, summer peak season of summer maize and summer rain and heat synchronization is conducive to the occurrence of brown spot disease, poor photosynthesis, leading to small spike, low yield, poor quality. Brown spot occurs in the late maize growth, the onset of the disease in the trumpet stage, heading stage to milky focus concentrated disease. The main hazard leaves, but also endanger leaf sheaths and stems. Symptoms first manifested in the tip of the tip of the blade, initially appeared brown or oval circular spots, lesions often gather along the veins to form a plaque, multiple plaque formation of lateral lesions