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Announcement! In 2016, Cornell’s Plant Disease Diagnostic Clinic identified the pathogen that causes Oak Wilt in two new locations in New York State. Go to the “Oak Wilt” link for more information.

The Plant Disease Diagnostic Clinic is a facility of the Department of Plant Pathology and Plant-Microbe Biology at Cornell University. The clinic provides fast and accurate plant disease diagnosis and up-to-date pest control recommendations for anyone from home owners to commercial growers. Services include analysis of plant material and soil for bacterial, fungal, viral, and nematode pathogen.


The Clinic promotes a "Test, Don't Guess" attitude. This is because we feel that knowing the pest affecting your plants and crops prior to treatment is essential for the best chances of recovery. The "Test, Don't Guess" policy allows for the appropriate selection and efficient use of control methods.

When sending a sample to the laboratory please include a Sample Submission Form. Please follow our collection tips when submitting samples! A sample that is improperly collected, packed, and/or shipped and arrives in poor shape is very difficult to diagnosis.

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Under the Scope

Weekly Diagnostic Review Reports are available here, and Feature Archives can be accessed here.

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Comprehensive collection of plant pest factsheets.

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Sample Submission Form

Please follow the submission guidelines to ensure your sample is properly collected, packed and shipped.

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Find an Expert

Have a question? Find the Cornell Cooperative Extension Office in your community.