Maple Trees With Anthracnose
- Anthracnose is a fungal disease caused by fungi in the genera gnomonia and gloeospotium, according to Iowa State University. Each species of fungi attacks a specific species of plant. Gardeners may see their maple tree exhibit signs of the disease during moist warm weather. Anthracnose is particularly severe in the rainy season. The disease needs leaf moisture to germinate. Also, rainwater spreads the disease to different parts of the maple tree. Check your maple trees when your region is experiencing high humidity and rainy weather.
- Infected maple trees display a brownish discoloration along the veins of leaves, according to the Ohio State University Extension. Gardeners who closely examine their maple leaves may see fungal growth. Heavily infected leaves may defoliate, or fall off. If the tree loses too many leaves, it may become stressed. Defoliation inhibits the maple tree's ability to photosynthesize. Trees that are compromised by the disease are targets for other pests, such as borers and other fungal diseases.
- Spray the maple tree with a fungicide that contains thiophanate-methyl, chlorothalonil or mancozeb, as directed by the Ohio State University Extension. Apply the fungicide at the maple's bud break or when the tree is growing new foliage. Reapply the fungicide according to its directions. Refrain from applying the fungicide if tree is water stressed. Fungicide applications to water stressed trees can further harm their health. Water your maple at the drip line and not on the leaves.
- Clean up all diseased debris underneath the maple tree. Diseased leaves can continually infect the maple tree. Bag up debris and burn or throw away. Avoid placing the debris in your compost. Fertilize the tree with a balanced fertilizer to encourage new growth. By providing nutrients, you help the tree increase its vigor. Also prune any branches that are causing too much shade inside the tree. Remove branches that are rubbing against each other or growing inward.
