Experts Challenge SilvaBio Claim That Genetically Engineered American Chestnut Tree Has Been “Validated”
For Immediate Release: 28 April 2026
SilvaBio, the corporation seeking to mass clone and sell genetically engineered American chestnut trees, released a press release on 25 April claiming “four independent studies” validate the blight tolerance of their Darling 54 (D54) trees. SilvaBio repackages limited, short-term and previously available studies to create the appearance of momentum for a deeply flawed tree.
Limited and Short-Term Studies
Two of the cited sources are from SUNY-ESF. SUNY-ESF developed Darling 54 (mislabeled D58), is seeking Darling 54’s federal deregulation, and commercially licensed the Darling 54 to SilvaBio. Other “new data” includes 2019 and 2020 studies from Purdue University, a 2025 study from the University of New England, and SUNY-ESF’s 2023 “Science Update” as its sources. (ACCESS Newswire)
Far from validating the “blight resistance” of the Darling 54, these studies show limited and short-term results: smaller cankers under controlled inoculation conditions in young trees during a 2 year study.
They do not demonstrate that Darling 54 is fit for long-term survival, reproduction, or restoration in wild forests. SUNY-ESF’s 2023 summary acknowledged that Darling 54 trees were shorter than their non-GE siblings and that the trials were in “early stages” and would need years of monitoring, which has not happened. (ESF)
The American Chestnut Foundation Withdraws Support
The American Chestnut Foundation (TACF), once a major backer of the Darling 54, withdrew its support after exposing evidence of inconsistent blight resistance, a deleted gene, stunted growth, decreased survival, and a serious mislabeling error caused by SUNY ESF. TACF concluded that due to Darling 54’s genetic issues, it should not be propagated beyond permitted sites. (The American Chestnut Foundation)
TACF also challenged ESF’s commercialization license: “Commercializing the transgenic American chestnut tree is contrary to statements made in regulatory filings and assurances given in public statements and to academic partners. The considerable support TACF provided to help [ESF] negotiate the regulatory process was based upon the understanding that a deregulated tree would be in the public commons.” (The American Chestnut Foundation)
Independent Scientific Studies Underscore Concerns
Independent scientific analysis underscores these concerns. Geneticist Dr. Ricarda Steinbrecher’s recent scientific briefing on the Darling line of GE chestnut trees states, “the [D54] GE trees do not function as intended or predicted by their developers.”
Fundamentally, Dr. Steinbrecher notes that “a reliable long term risk assessment for the use of GE forest trees is near impossible.” (EcoNexus)
“This isn’t a breakthrough—it’s damage control,” said Anne Petermann of Global Justice Ecology Project. “After the very public failure of Darling 58—which turned out to be a mislabeled Darling 54—old problems are being repackaged as progress. A deleted gene, human error, and inconsistent performance have already raised serious concerns.”
“Using two-year field trials to justify releasing a genetically engineered tree into wild forests is not science—it’s marketing,” she added.
Smaller cankers in young, controlled trials are not the same as proven forest restoration.
An Irreversible Experiment
Once genetically engineered trees are released, they cannot be recalled. The American chestnut is known to live for hundreds of years. It’s pollen, seeds, and genetic traits could spread for generations. It is for these reasons that 170,000 people publicly rejected this defective GE tree during the USDA’s last public comment period for the Darling 54.
Darling 54 must not be deregulated, commercialized, or released into wild forests.
We reject the release of genetically engineered trees into wild ecosystems and call for precaution, transparency, and support for non-GE forest restoration.
Global Justice Ecology Project works across the US and internationally to advance forest protection, climate justice and human rights. They coordinate the Campaign to STOP GE Trees.
Notes to Editors:
Genetically Engineered American Chestnut: Discussion of the Performance Limitations of Darling 58/54 (August 2024) https://www.econexus.info/publication/genetically-engineered-american-chestnut
The American Chestnut Foundation “Darling 58/54 FAQ” https://tacf.org/darling-58/
Center for Food Safety scientific review of the Darling 58/54 as submitted to the USDA (2023) https://www.regulations.gov/comment/APHIS-2020-0030-17301
The Darling 58 Debacle, Earth Island Journal https://www.earthisland.org/journal/index.php/magazine/entry/lessons-from-the-unsuccessful-gm-chestnut-experiment/
Press Release: 170,000+ Demand USDA Reject Proposal for Release of Genetically Engineered American Chestnut into Wild Forests (July 2025) https://stopgetrees.org/press-release-170000-demand-usda-reject-proposal-for-release-of-genetically-engineered-american-chestnut-into-wild-forests/
Once Wiped Out by Blight, Thousands of American Chestnut Trees are Thriving on Biologist’s Land in Maine, The Good News Network (2026) https://www.goodnewsnetwork.org/once-wiped-out-by-blight-thousands-of-american-chestnut-trees-are-thriving-on-biologists-land-in-maine/
Biotechnology for Forest Health? The Test Case of the Genetically Engineered American Chestnut (2019) https://stopgetrees.org/wp-content/uploads/2019/04/biotechnology-for-forest-health-test-case-american-chestnut-report-WEB-1.pdf
See a list of organizational and scientific comments submitted to the USDA regarding the petition to deregulate the Darling 58/54 GE American chestnut tree (January 2023) https://stopgetrees.org/chestnut-comments/
SilvaBio Press Release (25 April 2026) https://www.accessnewswire.com/newsroom/en/biotechnology/four-independent-studies-validate-the-blight-tolerance-of-darling-american-chestnut-t-1161220