危害症状温室栽培时切花菊叶斑病在整个生长期均可发生,湿度大、温度高时容易发生,蔓延速度快。主要危害菊花的下部叶片,发病初期叶片出现圆形或椭圆形黄色或褐色病斑,后期转为暗褐色凹陷的病斑,中心呈浅灰色,分生孢子形成后产生黑点,自下而上蔓延,严重时叶片变黄变黑干枯,久不脱落。 Danger symptoms Chrysanthemum leaf spot in the cultivation of greenhouse flowers can occur throughout the growing season, humidity, high temperature prone, rapid spread. The main damage to the lower leaves of chrysanthemum, the early onset of leaves appeared round or oval yellow or brown lesions, the latter turned to dark brown sunken spots, the center was light gray, black spots formed after the conidia, bottom-up Spread, serious when the leaves turn yellow black dry, long time off.