PENDLETON, S.C. — Clemson University’s Plant and Pest Diagnostic Clinic (PPDC), part of Regulatory Services, has earned Core Accreditation through the National Plant Diagnostic Network (NPDN). The designation recognizes the clinic’s quality management system and commitment to reliable plant diagnostics.
The accreditation took effect Oct. 1, 2026. Xiao Yang, laboratory quality manager; Jordan Withycombe-Green, assistant laboratory quality manager; and other PPDC staff worked together to develop and implement a quality management system that meets NPDN Core Accreditation Program requirements.
“Core Accreditation recognizes the effort our team puts into every step of plant diagnostics, from receiving a sample to communicating results. For our clients, it reflects our commitment to consistent, quality-focused diagnostic procedures they can trust when making decisions about managing plant problems and safeguarding plant health,” Yang said.
“Building and implementing our quality management system was a yearlong effort made possible by the dedication of our lab team and Ridgely Jackson, an accreditation intern with Clemson’s University Professional Internship and Co-op Program. We worked together to compile our lab documents, procedures and protocols into an updated, sustainable system that will allow us to continue providing consistent, high-quality diagnostic services,” Withycombe-Green said.
As of Oct. 1, 2026, 26 NPDN laboratories had earned Core Accreditation, including 21 at land-grant universities.
PPDC diagnoses plant and turf problems and provides management recommendations. Its work includes identifying diseases, nematodes, weeds, environmental issues, nutritional deficiencies and insect pests. The clinic also identifies insects that affect plants, structures, people, pets and livestock.
In 2025, PPDC diagnosticians processed 1,312 samples from 45 South Carolina counties and 15 other states. The clinic’s specialty services are provided through three laboratories: the Molecular Pathogen and Pest Detection Lab, the Nematode Assay Laboratory and the Commercial Turfgrass Clinic.
Clemson’s broader public-service laboratory community also includes the separate Agricultural Service Laboratory. Established in 1938 as a public soil-testing facility, it provides analytical testing for soil, plant tissue, feed and forage, animal waste, irrigation water, compost and research samples. The NPDN accreditation applies specifically to PPDC.
“Our PPDC is unique in the nation, serving the public as well as state and national regulatory programs from a university-based lab. This accreditation recognizes the strength of our lab and staff and our ability to support increased sample loads while maintaining high-quality plant diagnostics,” said Steven Long, assistant director of the Department of Plant Industry.
NPDN connects plant diagnostic professionals and laboratories across the United States. Established in 2002, the network supports plant health and biosecurity by strengthening diagnostic capacity, expertise, quality and partnerships. It also curates pest and disease detection data to inform decisions. NPDN operates through five regional centers and an IT center.
“Core Accreditation demonstrates a laboratory’s commitment not only to having a quality management system in place, but also to building a culture of quality that supports reliable, consistent diagnostic services. Clemson’s achievement is an important step in strengthening the quality and capacity of the NPDN, ultimately supporting the agricultural and biosecurity communities that depend on these laboratories,” said Stephanie A. Shea, NPDN accreditation program manager.
