地上部病害 褐斑病(Cercospora varricolor Winter)为牡丹常见病害之一,病原菌为芍药杂色尾孢霉菌(Cercospora varricolor Winter),以病叶组织内的菌丝体和分生孢子越冬,翌年以分生孢子侵染叶片。5月上中旬开始发病,植株下部的叶片首先发病,产生病斑,随着病斑的逐渐扩大,分生孢子的再次侵染,病菌向植株的上部蔓延,7月以 Cercospora varricolor Winter is one of the common diseases of peony, and the pathogen is Cercospora varricolor Winter. The mycelia and conidia in diseased leaves are overwintered. Conidia invade the leaves. The disease started in mid-May. The leaves of the lower part of the plant first appeared, causing the lesion. With the gradual enlargement of the lesion and the re-infection of the conidia, the bacteria spread to the upper part of the plant. In July