大叶黄杨受到白粉病的危害,受害部分初期呈淡灰色或褪绿小斑点,逐渐扩大为白粉状病斑,严重时迅速蔓延至整个叶片及嫩枝,造成叶片和嫩枝扭曲干枯而死亡。 发病适温为15℃～24℃,通风不良、光照不足、浇水过多、多雨过湿或长期无雨、空气过于干燥、植株过密都容易引起病害的繁殖和传播。白粉病的病原菌适应能力很强,春季或夏季都可能发病。由于真菌菌丝体能在休眠芽中越冬,若在入冬前不彻底清除病源,就会连年发病,给防治工作带来难度。 Euonymus japonicus is susceptible to powdery mildew. Some of the damaged parts are grayish-gray or chlorotic small spots at the initial stage, which gradually expand to white powdery spot and rapidly spread to the whole leaves and twigs in severe cases, resulting in the twisting and death of the leaves and shoots. . Disease onset temperature of 15 ℃ ~ 24 ℃, poor ventilation, lack of light, excessive watering, rainy or wet long-term, the air is too dry, too dense plants are likely to cause disease propagation and spread. Powdery mildew pathogenic bacteria adaptable, spring or summer may be disease. As the fungal mycelium can survive in the dormant buds, if the pathogen is not completely eliminated before winter, it will be year after year, which will bring difficulty to prevention and control work.