USDA deregulates blight-tolerant genetically engineered American chestnut

The Animal and Plant Health Inspection Service (APHIS) of the U.S. Department of Agriculture (USDA) has determined that the Darling 54 American Chestnut (Castanea dentata), developed through genetic engineering for tolerance to the fungal pathogen Cryphonectria parasitica, is no longer considered a regulated article. The change in regulatory status is recognized as of August 28, 2026, and was announced in a notice published in the Federal Register, Vol. 91, No. 166, under Docket No. APHIS–2020–0030 (FR Doc. 2026–17643).

The determination follows a petition for nonregulated status submitted by the State University of New York College of Environmental Science and Forestry (SUNY ESF). APHIS based its decision on an evaluation of the information and data in the petition, available scientific data, a plant pest risk assessment, and public comments received in response to earlier notices announcing the availability of the petition and a draft plant pest risk assessment.

What the decision means

Under the Plant Protection Act (7 U.S.C. 7701), the Secretary of Agriculture is authorized to prohibit or restrict the importation, entry, or movement of plants and plant pests to prevent the introduction or dissemination of pests and diseases. With this notice, APHIS advises the public that the Darling 54 American Chestnut no longer requires a permit or other regulatory oversight for movement within the United States.

The notice also announces the availability of APHIS’s written determination and supporting documents. The public can review the petition, the determination, and supporting materials through the following channels:

• The Federal eRulemaking Portal at www.regulations.gov, entering Docket No. APHIS–2020–0030 in the search field.
• The APHIS reading room at 1620 of the USDA South Building, 14th Street and Independence Avenue SW, Washington, DC, open 8 a.m. to 4:30 p.m., Monday through Friday, except holidays.

Background and significance

The American chestnut was once a dominant hardwood of eastern U.S. forests before the chestnut blight, caused by Cryphonectria parasitica, devastated the species in the early 20th century. The Darling 54 line is engineered to tolerate this fungal pathogen, making it a candidate for restoration efforts.

For further information, the notice directs inquiries to Mr. Alan Pearson, Biotechnology Regulatory Services, APHIS, USDA, at 5601 Sunnyside Ave., AP100, Beltsville, MD.

Why it matters

The deregulation of the Darling 54 American Chestnut marks a milestone both for the species’ restoration and for the regulation of genetically engineered trees in the United States. By removing the article from regulated status, APHIS clears a regulatory path for the tree’s broader use and distribution, potentially advancing efforts to return the American chestnut to its historic range.

Source: Federal Register, Vol. 91, No. 166, August 28, 2026, Notices, p. 55510 (official reference: Docket No. APHIS–2020–0030; FR Doc. 2026–17643).