主要症状:早疫病又称轮纹病,该病主要危害叶片、茎秆和果实。在发病初期,叶片上出现褐色或黑褐色圆形或椭圆形小病斑,逐渐扩大到4~6毫米,一般在病斑边缘具有浅绿色或黄色晕环,中部有同心轮纹。茎秆在发病时,一般在分叉处产生褐色或深褐色的不规则圆形或椭圆形病斑,表面有灰黑色霉状物。果实在发病时,病斑多在花萼附 The main symptoms: Early blight, also known as ring disease, the disease mainly endanger leaves, stems and fruits. In the early stages, the leaves appear brown or dark brown round or oval small lesions, gradually expanded to 4 to 6 mm, usually in the edge of the lesion with a light green or yellow halo, the central concentric pattern. Stems at onset, usually at the bifurcation of the brown or dark brown irregular round or oval lesions, gray-black mildew on the surface. When the fruit is on the disease, the lesion is mostly attached to the calyx