USDA Deregulates Blight-Tolerant American Chestnut, Paving Way for Restoration Efforts Amidst Public Debate
The U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) announced on August 28, 2026, its determination that the Darling 54 American Chestnut (Castanea dentata), a genetically engineered variety developed by the State University of New York College of Environmental Science and Forestry (ESF), no longer requires regulation under federal plant pest laws. This landmark decision marks a pivotal moment for efforts to restore the American chestnut, a species nearly eradicated by a devastating fungal blight.
The Blight and the Promise of Engineering
For over a century, the American chestnut, once a dominant tree in Eastern U.S. forests, has been decimated by Cryphonectria parasitica, commonly known as chestnut blight. This airborne fungus, introduced from Asia in the early 1900s, has reduced billions of trees to mere stump sprouts. The Darling 54 chestnut was engineered to express a gene from wheat that provides tolerance to this fungal pathogen, offering a beacon of hope for ecological restoration. ESF has championed this genetic engineering approach as a means to reintroduce a blight-resistant tree that retains the genetic characteristics of the native American chestnut.
A Long and Winding Regulatory Path
The path to deregulation for the Darling 54 chestnut has been protracted and subject to considerable public scrutiny. APHIS operates under the Plant Protection Act, which mandates the regulation of organisms developed through genetic engineering that are or are believed to be plant pests. ESF initiated the formal process on January 21, 2020, by submitting a petition for nonregulated status. Initially, the petition referred to a different line, Darling 58, but a subsequent amended petition in August 2024 corrected the designation to Darling 54. This correction was necessitated by a labeling error, with analyses revealing that nearly all offspring from initial crosses were derived from Darling 54.
Throughout the review, APHIS conducted multiple public comment periods. The initial public comment phase in August 2020 on ESF's petition saw a majority of comments favoring deregulation. However, as the process unfolded, public sentiment became more divided. A Notice of Intent (NOI) to prepare an Environmental Impact Statement (EIS) in August 2021 elicited a large majority of comments opposing deregulation. A subsequent release of a draft Plant Pest Risk Assessment (PPRA) and draft EIS in November 2022 once again saw a majority in favor. The publication of a revised draft EIS and PPRA in June 2025, following the corrected petition, notably garnered a large majority of comments in opposition to deregulation, indicating persistent and significant public concerns.
One critical development in this regulatory journey was APHIS's decision to withdraw its NOI for an EIS on August 18, 2025, effectively terminating work on the EIS. This meant the final determination would rest primarily on the PPRA rather than a comprehensive EIS.
The Basis for Deregulation
APHIS's ultimate determination of nonregulated status for Darling 54 is grounded in its evaluation of scientific data and information provided by ESF, including a comprehensive Plant Pest Risk Assessment. The agency concluded that the Darling 54 American Chestnut is
