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Welcome to the PDDC home page!

Please Note!

We do our best to always have at least one staff member present during normal business hours each day. However, it is always best to reach out to us before dropping off samples in-person to ensure we are available to receive your sample submission. We have two (2) full time staff members covering the Clinic and occasionally, both of us may need to be away for short periods of time. Additionally, we may have suggestions for the material you should include in your submission. Including images when you reach out for guidance is very helpful. Pictures of the overall symptoms or problem area and a close-up of the issue help us, help you!

Common Questions! 

Fees? Please go to the "Fees" link to see the current fee schedule and the services offered.

Pay using a credit card? To pay for your completed and invoiced sample submission using a credit card please use this secure link: Thank you!
Please do not use this link to pre-pay samples that have not yet been invoiced.

Sample submission? Contact the staff of the CU-PDDC via our general mailbox:, or see our sample submission instructions

Need to reach the diagnostician? You can reach Sandra Jensen at

Are you a state regulatory official? Please call or text Karen Snover-Clift at (607) 227-0397. Karen can also be reached at

The Plant Disease Diagnostic Clinic is a facility of the Section of Plant Pathology and Plant-Microbe Biology within the School of Integrative Plant Science 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 diagnose.

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Announcements and Upcoming Events

Check this area for Pest Alerts and upcoming meetings. NEW PEST ALERT 5-12-23


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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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Find an Expert

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