What is Dogwood Anthracnose?
Dogwood Anthracnose is a fungal disease that affects flowering dogwood trees (Cornus florida). The disease is caused by the fungus Discula destructiva and primarily impacts trees in the eastern United States. Dogwood Anthracnose can cause severe damage to infected trees, leading to leaf blight, twig dieback, and even death if left untreated.
What are the symptoms of Dogwood Anthracnose?
Symptoms of Dogwood Anthracnose typically appear in the spring and early summer. Infected trees may exhibit irregularly shaped, tan to reddish-brown spots on the leaves, which can eventually lead to leaf blight. Twigs may also show signs of dieback, with cankers forming on the bark. In severe cases, the disease can cause defoliation and even death of the tree.
How is Dogwood Anthracnose diagnosed?
Diagnosing Dogwood Anthracnose involves a combination of visual inspection of the tree’s symptoms and laboratory testing. A trained arborist or plant pathologist can examine the tree for characteristic signs of the disease, such as leaf spots and twig dieback. In some cases, a sample of the infected tissue may be sent to a diagnostic lab for further analysis to confirm the presence of the fungus.
What are the causes of Dogwood Anthracnose?
Dogwood Anthracnose is caused by the fungus Discula destructiva, which thrives in cool, wet conditions. The disease is most prevalent in areas with high humidity and frequent rainfall, making flowering dogwood trees in the eastern United States particularly susceptible. The fungus can spread through spores that are carried by wind, rain, or insects, infecting healthy trees and causing the disease to spread.
How can Dogwood Anthracnose be treated?
Treating Dogwood Anthracnose involves a combination of cultural practices and chemical treatments. Pruning infected branches to improve air circulation and reduce moisture can help prevent the spread of the disease. Fungicides containing active ingredients such as chlorothalonil or thiophanate-methyl can be applied to infected trees to control the fungus. It is important to follow label instructions and consult with a professional arborist before applying any chemical treatments.
How can Dogwood Anthracnose be prevented?
Preventing Dogwood Anthracnose involves maintaining healthy trees and implementing proper cultural practices. Planting disease-resistant dogwood varieties can help reduce the risk of infection. Avoiding overhead irrigation and watering at the base of the tree can help prevent excess moisture, which can promote fungal growth. Pruning trees to improve air circulation and removing infected plant debris can also help prevent the spread of the disease. Regular inspections by a trained arborist can help detect early signs of infection and prevent the disease from spreading.