Tree Diseases of Michigan

Monday, March 17, 2014 at 6:30 p.m.

Michigan is widely known for its serene forests, natural areas, and beautiful and productive orchards.  However, a changing environment and invasive organisms are leading to transformations throughout Michigan forests and landscape trees.  Widely publicized examples include oak wilt and beech bark diseases in the upper peninsula and northern lower peninsula, Dutch elm disease statewide, and the spread of the Emerald Ash borer infestation that began radiating from around Detroit.  Continuous economic challenges to Michigan orchards in the productive west and northwestern parts of the state include Fire Blight, Cherry knot, bacterial wilt and leaf curl diseases—and can lead to steep economic losses by farmers and orchardists. A significant epidemic that got its start around 1900 in the United States is a persistent threat to American and hybrid chestnut in both natural and nascent chestnut orchards throughout Michigan (and in the tree’s native range) is the destructive chestnut blight pathogen.  In addition to this historic and continuous disease in Michigan, a new epidemic called spruce decline is progressing throughout the state.