Dutch Elm Disease-
All Elms are susceptible to this disease.
A Injection of fungicide can help the tree but should be done every two years. Keeping the tree treated with insecticides can help prevent the spread of elm disasease.
If the tree is showing wide spread syptoms of the dieseases it may be difficult to save.
Fungicide are used but the fungicide only stays active for a two year period.
Wilting or yellowing in the canopy, followed by a distinct flagging of leaves.
Leaves brown and some hang on branches while others are quickly shed.
the first visible symptom is a rapid wilting of the leaves on one or more branches in the top of the tree
The leaves turn yellow and then brown, become shriveled and brittle and may be shed prematurely.
Note that Tips of affected branches often develop a characteristic downward hook-like curve. Wilted and discolored leaves usually start showing up about mid-June and are most evident during July and August
If caught early, it is possible to save trees by , pruning out infected limbs and injecting the tree with a fungicide.
The disease can spread throught the roots of elms if they join.
it cannot be saved. Infected Elms showing symptoms of more than 10-15 percent have a high risk for death.
Dutch elm disease fungal spores are carried on the bodies of these beetles and deposited in egg galleries. European elm bark beetles transmit the fungus by feeding on small twigs.
Native elm bark beetles expose the Dutch elm fungus to the trees.
After feeding, bark beetles seek breeding sites under the bark of dead or dying elms. The fungus develops and it produces spores and carrried by the young beetles to the next tree.
Black Leaf Spot (fungus , Small, yellow spots appear first on upper surface of leaves, then gradually develop a shiny black appearance. Heavy spotting causes leaf yellowing and early defoliation in wet seasons.
Wet wood or Slime Flux Chronic bleeding of sap from wounds or cankers in the trunk, which cause a discoloration of bark. Sap frequently is sour smelling.
Elm Leaf Scorch – A bacterium has been associated with this condition. Vascular bundles are plugged to the point where water movement in the tissues is impaired. No control is known.
Powdery Mildew Powdery whitish to gray growth on both sides of leaves. Affected leaves may be cupped, stunted, and show yellowing.