Guangzhou Fuerle Health Technology Co., Ltd , https://www.fuerlegroup.com
How to control poplar bacterial ulcer and rotten skin disease
Poplar bacterial ulcer and canker diseases are primarily found in the northeastern, northwestern, and northern regions of China. These diseases are common and frequently occur in shelterbelts, timber forests, and poplar trees planted in urban and rural areas. They are well-known worldwide as serious trunk diseases affecting poplar trees, and they often cause significant damage due to their widespread occurrence.
These diseases are caused by bacteria that naturally exist in the environment and can remain dormant within poplar trees for extended periods. The likelihood of infection is closely related to factors such as frost damage, sunburn, insect infestation, salt injury, and drought stress. Trees that have been heavily transplanted or have excessive root pruning may struggle to recover after planting, making them more vulnerable to disease.
Additionally, many poplar varieties are highly susceptible in years with unfavorable environmental conditions, such as drought, heat stress, sunburn, or frost. In such cases, the disease can develop rapidly, leading to severe losses in both forest and ornamental plantings.
Symptoms of the disease typically appear on the branches and trunks of poplar trees. In early spring and summer, dark brown, water-soaked lesions form on young shoots, creating small raised bumps. Over time, these bumps may dry out, shrink, and crack. Underneath the bark, soft rot can be observed, and the phloem and xylem in the affected area may show discoloration.
As the disease progresses, the discolored areas begin to crack in summer, releasing a foul-smelling brown mucus. In later stages, the tumors continue to grow, and wounds do not heal. When humidity is high or during rain, black spots appear on the damaged skin, and a milky white substance oozes from them, eventually turning orange. If left unchecked, the disease can spread up the branches and down to the roots, causing internal wood decay, discoloration, and the formation of dead branches.
The pathogenic bacteria can survive in infected bark for many years. In the following spring, during wet and rainy weather, the bacteria become active. In northern China, the disease usually starts in mid-to-late March, while in the northeast, it appears later, typically between May and June. The disease becomes less severe in July and stops developing by September. The bacteria spread through cracks in the bark, aided by rain, wind, insects, birds, and human activities. They enter the tree through wounds, leaf scars, bud scales, or other openings.
To prevent and control the disease, strict quarantine measures must be enforced. Diseased seedlings and cuttings should not be transported, and any suspicious material must be disinfected. Before planting imported seedlings or cuttings, they should be isolated and tested to ensure they are free of disease. Using disease-resistant poplar varieties is also an effective strategy.
Infected trees should be removed and destroyed promptly. For prevention, a mixture of Tianlin Plant Energy (600 times), Tianda 2116 Cell Membrane Stabilizer (600 times), and Tianda Organic Silicon (6000 times) can be applied in early spring and late autumn. For already infected trees, a combination of Tianda 2116 (50 times), Tianlin Plant Energy (50 times), and Tianda Silicone (100 times) can help strengthen the tree and promote recovery.