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一、褐斑病发病症状该病主要发生在玉米叶片、叶鞘及茎秆上。先在顶部叶片的尖端发生,最初为浅黄色,逐渐变为黄褐色或深褐色小斑点,病斑呈圆形或椭圆形,严重时叶片上出现几段甚至全部布满病斑,在叶鞘上和叶脉上出现较大的褐色斑点,发病后期病斑的表面破裂,叶细胞组织呈坏死状,散出褐色粉末(病原菌的孢子囊),病叶局部散裂,叶脉和维管束残存如丝状。农业措施1.玉米收获后彻底清除病残体组织,并深翻土壤;施足底肥,适时追肥。一般应在玉米4~5片叶期追施苗肥,每667平方米追施氮、
First, the incidence of brown spot symptoms The disease occurs mainly in corn leaves, leaf sheaths and stems. First in the tip of the top of the blade occurs, initially light yellow, gradually become brown or dark brown spots, the lesion was round or oval, serious when the leaves appear several or even all covered with lesions on the leaf sheath And the veins appear larger brown spots, the onset of lesion surface rupture, necrosis of the leaf cell tissue, scattered brown powder (pathogenic bacteria sporangia), diseased leaves local splinter, veins and vascular bundles such as residual filamentous . Agricultural measures 1. Corn harvest after the complete removal of diseased tissue, and deep turn the soil; Shi enough base fertilizer, timely top dressing. Generally 4 to 5 leaves of corn should be topdressing Miao, every 667 square meters topdressing nitrogen,