Dothistroma Needle Blight
Need to know:
- Brown bands will appear on infected needles and the portion beyond the band will die.
Overview of Dothistroma needle blight
Dothistroma needle blight is especially common on Austrian pines.
Symptoms of Dothistroma needle blight
Early symptoms of dothistroma needle blight include resin-soaked needles with dark green bands and spots that may be dark green, yellow, or tan in color. Trees are often affected from the bottom of the canopy working up. As the disease progresses the bands and spots turn to a brown or reddish-brown color. In the fall or over winter the parts of the needle past the band may die and turn brown.
See this article about Dothistroma needle blight.
Early symptoms of dothistroma needle blight include resin-soaked needles with dark green bands and spots that may be dark green, yellow, or tan in color. Trees are often affected from the bottom of the canopy working up. As the disease progresses the bands and spots turn to a brown or reddish-brown color. In the fall or over winter the parts of the needle past the band may die and turn brown.
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.
Fungicide applications may be avoided by following good Integrated Pest Management practices like those listed in this encyclopedia article. Often, the only preventative application is effective to manage plant diseases. If the problem requires a fungicide, state law requires the user to read and follow all labels accordingly. For more information, read Proper fungicide use.
Lina Rodriguez Salamanca Extension Plant Pathologist and Diagnostician
Dr. Lina Rodriguez-Salamanca is a diagnostician and extension plant pathologist with the Iowa State University Plant and Insect Diagnostic Clinic (clinic.ipm.iastate.edu), a member of the National Plant Diagnostic Network (NPDN, ...
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