# Pioneer Hi-Bred International, Inc.; Availability of a Request and Plant Pest Risk Similarity Assessment for an Extension of Determination of Nonregulated Status for Maize (Corn) Genetically Engineered for Insect Resistance and Herbicide Tolerance
**AGENCY:**
Animal and Plant Health Inspection Service, USDA.
**ACTION:**
Notice of availability.
**SUMMARY:**
We are advising the public that the Animal and Plant Health Inspection Service has received a request to extend our determination of nonregulated status of Pioneer Hi-Bred International, Inc.'s (Pioneer's) DP23211 insect-resistant and glufosinate-ammonium-tolerant maize (corn) to DP51291 maize (corn). Similar to DP23211 corn, DP51291 corn was genetically engineered to express the IPD072Aa protein for control of certain susceptible corn rootworm pests, the phosphinothricin acetyltransferase protein as a selectable marker and for tolerance to glufosinate herbicide, and the phosphomannose isomerase protein as a selectable marker. We are making the extension request, our draft plant pest risk similarity assessment, and preliminary determination of nonregulated status available for public review and comment.
**DATES:**
We will consider all comments that we receive on or before April 6, 2026.
**ADDRESSES:**
You may submit comments by either of the following methods:
• *Federal eRulemaking Portal:* Go to *www.regulations.gov.* Enter APHIS-2025-0411 in the Search field. Select the Documents tab, then select the Comment button in the list of documents.
• *Postal Mail/Commercial Delivery:* Send your comment to Docket No. APHIS-2025-0411, Regulatory Analysis and Development, PPD, APHIS, 5601 Sunnyside Ave., #AP760, Beltsville, MD 20705.
The extension request, draft plant pest risk similarity assessment, preliminary determination of nonregulated status, and any comments we receive on this docket may be viewed at *www.regulations.gov* or in our reading room, located in 1620 of the USDA South Building, 14th Street and Independence Avenue SW, Washington, DC. Normal reading room hours are 8 a.m. to 4:30 p.m., Monday through Friday, except holidays. To be sure someone is there to help you, please call (202) 799-7039 before coming.
**FOR FURTHER INFORMATION CONTACT:**
Mr. Alan Pearson, Biotechnology Regulatory Services, APHIS, USDA, 5601 Sunnyside Avenue, AP100, Beltsville, MD 20705; (301) 851-3944; email: *[email protected].*
**SUPPLEMENTARY INFORMATION:**
Under the authority of the plant pest provisions of the Plant Protection Act (7 U.S.C. 7701 *et seq.* ), the regulations in 7 CFR part 340, “Introduction of Organisms and Products Altered or Produced Through Genetic Engineering Which Are Plant Pests or Which There Is Reason to Believe Are Plant Pests,” regulate, among other things, the introduction (importation, interstate movement, or release into the environment) of organisms and products altered or produced through genetic engineering that are plant pests or that there is reason to believe are plant pests. Such organisms and products are considered “regulated articles.”
Section 340.6(e)(2) of the regulations provides that any person may request that APHIS extend a determination of nonregulated status to other organisms. Such a request shall include information to establish the similarity of the antecedent organism and the regulated article in question.
On December 1, 2023, APHIS announced [^1] its determination of nonregulated status of Pioneer Hi-Bred International, Inc.'s (Pioneer) DP23211 maize (corn), and the herbicide active ingredient glufosinate-ammonium (hereafter referred to as DP23211 maize) and progeny derived from it. DP23211 maize was developed using genetic engineering for resistance to western corn rootworm. APHIS has received a request for an extension of that determination of nonregulated status of DP23211 maize to insect resistant and herbicide tolerant maize DP-Ø51291-2 referred to as DP51291 (APHIS Petition Number 25-171-01ext), also from Pioneer. In its request, Pioneer stated that this maize is similar to the antecedent organism DP23211 maize, and, based on the similarity to the antecedent organism, is unlikely to pose a plant pest risk and, therefore, should not be a regulated article under APHIS' regulations in 7 CFR part 340.
[^1] To view the notice, go to *www.regulations.gov* and enter APHIS-2020-0098 in the Search field.
Similar to DP23211 maize, DP51291 maize was genetically engineered to express the IPD072Aa protein for control of certain susceptible corn rootworm pests. Also similar to DP23211 maize, DP51291 maize was genetically engineered to express the phosphinothricin acetyltransferase protein as a selectable marker and for tolerance to glufosinate herbicide, and the phosphomannose isomerase protein as a selectable marker. Further, DP51291 maize was developed using site-specific integration similar to DP23211 maize.
APHIS has prepared a plant pest risk similarity assessment (PPRSA) to compare DP51291 maize to the antecedent DP23211 maize. APHIS has analyzed information submitted by Pioneer, references provided in the extension request, peer-reviewed publications, and supporting documentation prepared for the antecedent organism. Based on APHIS' analysis of this information and the similarity of DP51291 maize to the antecedent DP23211 maize, APHIS has determined that DP51291 maize is unlikely to pose a plant pest risk. We have therefore reached a preliminary decision to approve the request to extend the determination of nonregulated status for DP51291 maize, whereby DP51291 maize would no longer be subject to our regulations in 7 CFR part 340 governing organisms developed using genetic engineering.
We are therefore publishing this notice to make available our evaluation and inform the public of our preliminary decision to extend the determination of nonregulated status for DP51291 maize.
APHIS will accept written comments on the request for extension, PPRSA, and our preliminary determination for DP51291 maize for 30 days. These documents are available for public review as indicated under *ADDRESSES* and from the individual listed under the *FOR FURTHER INFORMATION CONTACT* .
After the comment period closes, APHIS will review all written comments received during the comment period and any other relevant information. All comments will be available for public review. After reviewing and evaluating the comments, if APHIS determines that no information has been received that would warrant APHIS altering its preliminary regulatory determination, our preliminary regulatory determination will become final and effective upon notification of the public through an announcement on our website at *https://www.aphis.usda.gov/aphis/ourfocus/biotechnology/permits-notifications-petitions/petitions/petition-status.* APHIS will also furnish a response to the petitioner regarding our final regulatory determination. No further *Federal Register* notice will be published announcing the final regulatory determination of DP51291 maize.
*Authority:* 7 U.S.C. 7701-7772 and 7781-7786; 31 U.S.C. 9701; 7 CFR 2.22, 2.80, and 371.3.
Done in Washington, DC, this 3rd day of March 2026.
Kelly Moore,
Acting Administrator, Animal and Plant Health Inspection Service.