Overview of Dothistroma needle blight
Dothistroma needle blight is especially common on Austrian pines.
Signs and symptoms of Dothistroma needle blight
Affected needles develop brown bands, and the portion of the needle beyond the band dies. Trees are often affected from the bottom of the canopy working up.
See this article about Dothistroma needle blight.
Type of Sample Needed for Diagnosis and Confirmation
The Iowa State University Plant & Insect Diagnostic Clinic can help you to investigate and confirm if you plant has this disease. Please see our website for current forms and fees. Contact information for each states diagnostic laboratory for U.S. residents. If your sample is from outside of Iowa please do not submit it to the Plant & Insect Diagnostic Clinic without contacting us
To confirm Dothistroma needle blight we need to examine a sample under the microscope. Samples should include symptomatic needles, living and still attached to a branch. Branches can be packed into a box with paper towel for shipping. DO NOT add water to the samples. If you are uncertain about the type of sample feel free to contact us.