乐亭县是一个蔬菜生产大县,温室大棚甜瓜种植面积达10余万亩,随着种植年限的延长,各种病害发生越来越重,自2010年开始,在甜瓜产区发生了细菌性叶枯病危害,此病对甜瓜的产量和品质构成了严重的威胁。一、发病的症状主要为害叶片,也可为害果实,发病初期,叶片上呈现水浸状褪绿斑,逐渐扩大呈近圆形或多角形,直径1—2毫米,周围具褪绿晕圈,病叶背面不易见到菌脓,从而与细菌性角斑病相区别, Laoting County is a vegetable production county, melon greenhouse cultivation area of ​​more than 10 acres, with growing years, a variety of diseases occur more and more heavy, since 2010, occurred in the melon producing bacteria Leaf blight hazards, the disease on the yield and quality of melon pose a serious threat. First, the incidence of symptoms of the main damage leaves, but also harmful fruits, early onset, the leaves appear flooding-like chlorotic spots, gradually expanding was nearly circular or polygonal, 1-2 mm in diameter, surrounded by chlorotic halo halo, Sick leaves the back is not easy to see the bacteria pus, and bacterial angular leaf disease are different,