Healthy Trees, Healthy Communities

Troubleshooting Tree Problems xviii

Symptoms

Possible disorder

Irregular spots, and dead areas on leaves that often follow the veins of the leaves.

Anthracnose

Defoliation of trees, holes in leaves and egg masses on tree trunks or any outdoor furniture

Spongy moth infestation

Dieback of leaves and twigs on major portions of a tree.

Blight

Infected wood often found on conifer that has a dry, burnt, cubical appearance.

Brownrot (Sometimes called Dryrot)

Defoliation of leaves. Tent-like web in tree.

Eastern Tent Caterpillar or Fall Webworm infestation

Localized dead tissue, often discolored, and shriveled.

Canker

Yellowing of green tissues because of a lack of chlorophyll.

Chlorosis

Rotting or decomposing wood tissue in the tree. Wood cells are breaking down in the tree. Swollen or irregular growth that may be induced by insects or other organisms. Oozing sap or gum from wounds or openings. Dead areas on the foliage, bigger than leaf spots and irregular in shape. Discolored spots of dead tissue on the foliage, usually on small areas of a leaf.

Decay

Gall

Gummosis Leaf blotch

Leaf spot

Dead tissue.

Necrosis

White or gray fungal growth on leaves or stems. Orange to red/brown pustules on leaves, or fruit.

Powdery mildew

Rust

Browning, dead areas around the margins of leaves or between leaf veins. Wood has a water-soaked or burnt look in areas that appear infected.

Leaf scorch

Soft Rot

Abnormally small growth on the tree.

Stunting

Darkening of the tree wood vascular areas, often along growth rings. Bleached appearance on wood, typically on broadleaf trees. May appear in a hollow in the tree.

Vascular discoloration

Whiterot

Drooping leaves or shoots.

Wilt

Abnormal development of multiple shoots.

Witch’s broom

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