4落葵圆斑病①症状主要为害叶片，苗期、生育后期均可发生，初在叶缘或叶面现圆形或半圆形大小木等的凹陷斑，病斑中间褪为白色至灰白色，从褪色部向外一圈紫褐色或红褐色圈，褪色部与紫褐色圈及其与健部交界明显，故病斑形状似鸟眼。植株衰老时，叶片枯死，病班上长出灰黑色霉 4 Fallen leaves spot ① The main symptoms of damage leaves, seedling, reproductive late may occur at the beginning of the leaf margin or leaf surface is round or semicircular size wood and other concave spots, the lesion faded to white to gray , Outward from the faded Department purple brown or reddish brown circle, fade Department and purple brown circle and its obvious junction with the Department of Health, so the lesion shape is like a bird’s eye. When the plants are senescing, the leaves are dead and the gray black mold grows on the diseased classes