USDA Deregulates American Chestnut Engineered for Enhanced Blight Tolerance

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American chestnut

Contact: aphispress@usda.gov

WASHINGTON, D.C., August 27, 2026—The U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) is deregulating State University of New York College, Environmental Science and Forestry’s (SUNY-ESF) Darling 54 American chestnut. This American chestnut variety was developed using genetic engineering to enhance tolerance to chestnut blight caused by fungal pathogen Cryphonectria parasitica. After a thorough review, APHIS has determined that the modified American chestnut is unlikely to pose a greater plant pest risk than the unmodified comparator and therefore is no longer subject to our regulation governing the introduction of certain organisms developed using genetic engineering.

Our determination is based on our evaluation of the following:

  • Information and data SUNY-ESF submitted in its petition for deregulation
  • Available scientific data
  • Public comments received in response to the November 10, 2022, Federal Register notice announcing the availability of the draft plant pest risk assessment (PPRA)
  • Public comments received in response to the June 6, 2025, Federal Register notice announcing the availability of the revised petition and revised draft plant pest risk assessment (PPRA)

We are publishing the Determination of Nonregulated Status, PPRA, and response to public comments on the petition and draft PPRA. These documents support APHIS’ review and analysis of any potential plant pest impacts associated with deregulating SUNY-ESF’s American chestnut modified for enhanced blight tolerance. 

These documents and the Federal Register notice will be available on the Regulations.gov website on August 28, 2026. Enter “APHIS-2020-0030” into the "Search" field.