病害症状溃疡病主要危害树干,是一种慢性病,初期在皮孔边缘形成小泡状溃疡斑,圆形,极小。随后小泡变大鼓起,大小不等,泡内充满褐色液体,破裂后液体流出,遇空气变为铁锈色。继而病斑干缩下陷,中间有一裂缝。重病树病斑连成一 Disease symptoms Canker disease is a major risk to the trunk, is a chronic disease, the initial formation of vesicle-shaped ulcers on the edge of lenticels, round, very small. Then bulge bulge, size, bubble filled with brown liquid, rupture of liquid outflow, in case of air into rust color. Then shrink dry shrink depression, the middle of a crack. Severe disease spots into one