北京1960年普遍发生桃树腐烂病(Leucostoma Spp.),被害株达24—90%。1960—1961年两年来的研究指出:其为害部位,主要集中在主干与主枝上,两者合计占树体病疤总数之80%。其中主干与主枝基部被害尤多。主干症状表现为流胶,内部皮层腐烂呈红棕色,可直达木质部。枝条上虽亦流胶,然在老龄与弱枝上则以长条凹斑形式发展, Beijing 1960 Peach tree rot disease (Leucostoma Spp.), The victim strain of up to 24-90%. The study from 1960 to 1961 pointed out that the damaged parts mainly concentrated on the trunk and main branches, which together accounted for 80% of the total number of tree scars. Among them, the main stem and the main branch were particularly victimized. The main symptoms of the flow of plastic, decay internal cortex was reddish brown, direct access to xylem. Although the branches also flow plastic, but in the aging and weak branches in the form of a long concave plaque development,