近年来,随着保护地西芹栽培面积的增加,斑枯病发生有逐年加重的趋势,严重年份发病率高达70%以上,已经引起了广大菜农的重视。(1)病害症状西芹斑枯病有大斑型和小斑型两种。北方以小斑为主。叶片受害,两型病斑早期相似。病斑初为淡褐色油渍状小斑点,大斑型病斑可继续扩大到3～10毫米,多散生,边缘明显,外缘深褐色,中间褐色,在中央散生小黑点;小斑型病斑一般为0.5～2毫米,边缘明显,外缘黄褐色,中间黄白色至灰白 In recent years, with the increase of cultivated area of ​​celery in protected areas, the occurrence of spot blight has been increasing year by year. The incidence in serious years is as high as over 70%, which has attracted the attention of the majority of farmers. (1) disease symptoms Platycodon grandiflora has two large spots and small spots. North to patchy dominated. Leaf damage, two types of lesions early similarities. Lesions as a light brown early spot of small stains, large spot type spots can continue to expand to 3 to 10 mm, more scattered, obvious edges, dark brown outer edge, the middle brown, scattered in the central black spots; small spots Type lesions are generally 0.5 to 2 mm, the edge is obvious, the outer edge of tan, the middle yellow to white