Search The Connecticut Agricultural Experiment Station Filtered Topic Search
The Plant Disease Information Office

The Plant Disease Information Office (PDIO) is part of the Department of Plant Pathology and Ecology at The Connecticut Agricultural Experiment Station (CAES). The PDIO is a full-service plant disease diagnostic laboratory that assists all Connecticut stakeholders, including homeowners and professionals.  Plant samples are diagnosed utilizing molecular, serological, biochemical, and traditional diagnostic methods. The PDIO also assists with inquiries about plants, plant identification, and plant health. Inquiries and samples can be submitted via phone, email, mail, and in person. More information can be found in the Sample Submission and  PDIO Brochure sections.

Contact Information

Dr. Yonghao Li, Plant Pathologist
Phone: (203) 974-8601
Toll Free Phone: 1-877-855-2237

Office Hours: The PDIO is open 8:30 a.m. to 4:30 p.m. Monday - Friday

PDIO Hours of Operation and Holiday List

PDIO Mailing Address

Plant Disease Information Office
The Connecticut Agricultural Experiment Station
P.O. Box 1106
New Haven, CT 06504

Office Location Address

(use this address for UPS and FedEx, as well as to visit)

Plant Disease Information Office
Jenkins-Waggoner Laboratory
Connecticut Agricultural Experiment Station
123 Huntington Street
New Haven, CT 06511
Photo of Jenkins-Waggoner Laboratory
Follow this link for a map to the CAES New Haven campus

Sample Submission

Link to Sample Submission Page


- Fact Sheet and other Publications -

Link to Publication Page

What's New

- Updates, Alerts, and News from the PDIO -

Link to What's New Page

Image Gallery

This gallery contains images of common plant disease problems which occur in Connecticut. Clicking the link below an image will open a fact sheet which explains the disease and options for management.

Link to Image Gallery Page


--Boxwood Blight Information--

Boxwood Blight

The Experiment Station's PDIO is a member of the National Plant Diagnostics Network (NPDN) and the Northeast Plant Diagnostic Network (NEPDN)