近几年来,随着引进和培育杨树品种的增多,育苗面积的扩大,杨苗灰斑病相继发生。叶片被害后,引起苗木提早落叶,嫩梢被害后,常枯萎死亡,重生嫩芽,造成丛枝,严重影响苗木正常生长。为了解决对该病的防治问题,我们在1975年进行了药剂防治试验。试验情况如下: 一、室内药效试验 In recent years, with the introduction and cultivation of poplar varieties increased, nursery area expansion, poplar gray spot disease have occurred. After the leaves were killed, the seedlings were caused to fall earlier. After the young shoots were killed, they often wilted and died, which regenerated the shoots and caused the branches, which seriously affected the normal growth of the seedlings. In order to solve the problem of prevention and treatment of the disease, we carried out pharmaceutical control trials in 1975. Test conditions are as follows: First, the indoor efficacy test