白粉病是园林植物发生既普遍又严重的病害,除针叶树外,许多观赏植物都会发生白粉病。这类病害,病症常先于病状,病状最初不明显。病症初为白粉状,近圆形斑,扩展后病斑可联结成片。一般来说,秋季时白粉层上出现许多由白转黄、最后变为黑色的小点粒——闭囊壳。白粉病降低植物观赏性、切花产量,削弱植物生长态势。 Powdery mildew is a common and serious disease occurred in garden plants, in addition to conifers, many ornamental plants will occur powdery mildew. Such diseases, illness often precede the symptoms, the initial symptoms are not obvious. Early symptoms of white powder, nearly circular plaque, extended lesion can be linked into tablets. In general, there are many small particles called white vesicles turning yellow from white to black in the fall, and the vesicle is closed. Powdery mildew reduces plant ornamentation, cut flower yield, weaken the growth of plants.