牡丹常见的病害主要有叶斑病、褐斑病、锈病、白粉病、根结线虫病、炭疽病等。叶斑病此病的病原多为毛胞属的真菌,主要侵染叶片、新枝。一般在花后15天即五月中旬为发病初期,随7月中旬气温上升而加重。表现病状:初期叶背有褐色斑点,边缘略深,为不规则圆心环纹枯斑,枯斑连通后叶片枯焦凋落。病菌在病株、茎、叶、土壤中过冬。防治方法:入冬前将落叶焚烧,消除病源,花后及时喷波尔多液(1:1:160倍),1周1次至7月底。褐斑病病源为黑座孢,主要危害叶部。初期叶背出现2—10mm圆点,中心渐成黄褐色或灰褐色。正面呈细小黑点,显微 Peony common diseases are leaf spot, brown spot, rust, powdery mildew, root knot nematode disease, anthrax and so on. Leaf spot disease pathogens and more for the genus Genus fungi, the main infection leaves, new branches. Generally 15 days after flowering in mid-May for the early onset, with the temperature rise in mid-July and aggravate. The performance of symptoms: the early leaves brown spots, slightly darker edge of the ring for the irregular ring spot, dead leaf patchy connectivity litter clumps. Germs in the diseased plants, stems, leaves, soil winter. Prevention and treatment methods: before the winter will be deciduous burning, eliminate the source, after the flower spray Bordeaux mixture (1: 1: 160 times), 1 week 1 to the end of July. Brown spot disease source for the black sertoli, the main hazard leaves. 2-10mm dots appear on the back of the leaves in the early stage, and the center becomes yellowish brown or grayish brown. Positive small black spots, microscopic