猝倒病也称立枯病,在我国各地苗圃普遍发生,幼苗死亡率很高,严重的达50%以上,是许多针阔叶树幼苗的主要病害。1症状病害多在4～6月间发生,因发病时期不同,可出现四种症状类型。(1)种腐型:播种后,土壤潮湿板结,种芽出土前被病菌侵入,破坏种芽的组织,未出土就引起腐烂,地面表现为缺苗。 Damp down disease, also known as blight, is common in nurseries all over China. The mortality rate of seedlings is very high, reaching over 50%, which is the main disease of many coniferous and deciduous tree seedlings. 1 Symptoms Mostly occur in 4 to 6 months, due to different stages of onset, there may be four types of symptoms. (1) Kind of rot: After sowing, the soil is wet and compacted, the germs invade before the seed germination, and the tissue that destroys the seed germination causes decay without being unearthed, and the ground is lack of seedlings.