Identification and control of poplar canker

The typical symptoms of poplar canker disease can be divided into two types: ulcer type and withered tip type. In the early stage of ulcerative disease, brown round or oval bark appeared in the infected tree trunk, showing waterlogged or blister-like disease spots, and there was liquid outflow under hand pressure. After the blister burst, the liquid flowed out with wine lees, the disease part shrank and sank into ulcer spots, and the cortex of the lesions became brown and rotten. The withered tip type mostly occurred in the young trees in the same year, and there were inconspicuous small spots on the trunk, showing reddish brown. 2-3 days later, the disease spot quickly surrounded the trunk, resulting in the death of the upper tip. Poplar canker pathogen usually exists in the bark in a latent state, and poplar seedlings can be infected in the nursery, and the incidence of poplar seedlings transplanted in spring is the highest. The disease begins in the middle of April every year, and the peak period is from late May to June. Prevention and control methods: do a good job in the origin quarantine and transportation quarantine of poplar seedlings in the disease area, so as to avoid planting susceptible seedlings. At the same time, strengthen fertilizer and water management, enhance the tree potential, avoid trauma, and enhance the resistance of trees. For the infected trees, methyl topiramate, carbendazim and other pesticides can be used to brush the trunk, trunk injection, root irrigation or crown spray control. Seriously diseased trees should be truncated and diseased branches and dead trees should be removed.