杨树灰斑病(Coryneum populinum Bres)是东北地区杨树的主要病害之一。该病在黑龙江省各地都有不同程度的发生,特别是小黑杨苗期发病严重,经济损失很大。对灰斑病的防治已经有了较好的方法,但到目前为止,该病对苗木所造成的损失程度尚不十分清楚。搞清该病的为害损失,将为防治提供科学的依据。而林病的防治需要有充分的时间准备,并 Corylus populinum Bres is one of the major diseases of poplar in Northeast China. The disease in different parts of Heilongjiang Province have occurred in varying degrees, especially the young black poplar seedlings serious illness, great economic loss. The prevention and cure of gray spot disease already has a better method, but so far the extent of damage caused by the disease to seedlings is not well understood. To find out the damage caused by the disease will provide a scientific basis for prevention and treatment. The prevention and treatment of forest disease need to have sufficient time to prepare, and