Pioneer Hi-Bred International, Inc. Petition (20-203-01p) for 

the Determination of Nonregulated Status for Insect 

Resistant and Herbicide-Tolerant DP23211 Maize

OECD Unique Identifier: DP-Ø23211-2

Final Environmental Assessment 

October 2023

Agency: United States Department of Agriculture, Animal and Plant Health Inspection

Service, Biotechnology Regulatory Services

Agency Contact: 

Alan Pearson

USDA, APHIS 

Biotechnology Regulatory Services 

4700 River Road 

Riverdale, MD 20737

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information. 
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TABLE OF CONTENTS Page

1 PURPOSE AND NEED FOR AGENCY ACTION.............................................................................................. 1-1

1.1 BACKGROUND ...............................................................................................................................................1-1

1.2 PURPOSE OF DP23211 CORN..........................................................................................................................1-1

1.3 COORDINATED FRAMEWORK FOR THE REGULATION OF BIOTECHNOLOGY ..................................................................1-3

1.4 REQUIREMENT TO ISSUE A REGULATORY STATUS DETERMINATION ..........................................................................1-4

2 SCOPING AND PUBLIC INVOVLEMENT...................................................................................................... 2-1

2.1 PUBLIC INVOLVEMENT FOR PETITION 20-203-01P ..............................................................................................2-1

2.2 ISSUES CONSIDERED IN THIS EA ........................................................................................................................2-1

3 ALTERNATIVES ........................................................................................................................................ 3-1

3.1 NO ACTION ALTERNATIVE: DENY THE PETITION REQUEST ......................................................................................3-1

3.2 PREFERRED ALTERNATIVE: APPROVE THE PETITION–ISSUE A DETERMINATION OF NONREGULATED STATUS FOR DP23211

CORN 3-1

3.3 SUMMARY OF THE NO ACTION AND PREFERRED ALTERNATIVE ANALYSES..................................................................3-1

4 AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES......................................................... 4-1

4.1 SCOPE OF ANALYSIS........................................................................................................................................4-1

4.2 NO ACTION ALTERNATIVE: DENY THE PETITION REQUEST ......................................................................................4-3

4.3 PREFERRED ALTERNATIVE: APPROVE THE PETITION REQUEST..................................................................................4-4

4.3.1 U.S. Corn Production.............................................................................................................................4-4

4.3.2 Physical Environment..........................................................................................................................4-28

4.3.3 Biological Resources ...........................................................................................................................4-37

4.3.4 Human Health.....................................................................................................................................4-65

4.3.5 Livestock Health and Welfare .............................................................................................................4-70

4.3.6 Socioeconomics...................................................................................................................................4-71

4.3.7 Climate Change and Greenhouse Gas Emissions................................................................................4-79

4.3.8 Compliance with Federal and State Laws and Regulations, Executive Orders, Policies, and Treaties4-84

4.3.9 Conclusions: Potential Impacts on the Human Environment..............................................................4-88

APPENDIX 1: THREATENED AND ENDANGERED SPECIES .................................................................................A1-1

APPENDIX 2: PUBLIC COMMENTS RECEIVED ON THE DRAFT ENVIRONMENTAL ASSESSMENT .........................A2-1

APPENIDX 3: LIST OF PREPARERS ...................................................................................................................A3-1

APPENDIX 4: REFERENCES.............................................................................................................................. A4-1
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LIST OF TABLES Page

Table 3-1. Summary of Potential Impacts for the Alternatives Considered............................................. 3-1

Table 4-1. Summary of Genetic Elements in DP23211 Corn .................................................................... 4-2

Table 4-2. Top Practices in Pest Management, 2018 Crop Year .............................................................. 4-7

Table 4-3. Fertilizer Applied to Corn Acres, 2021 Crop Year.................................................................... 4-9

Table 4-4. Herbicide Use in U.S. Corn Production – 2021 ...................................................................... 4-11

Table 4-5. Glufosinate Resistant Corn, Soybean, and Cotton Crops...................................................... 4-13

Table 4-6. Soil and Foliar Applied Insecticide Use in Corn – 2018.......................................................... 4-18

Table 4-7. Effects of DvSSJ1 dsRNA on Coleoptera and Lepidoptera Species........................................ 4-24

Table 4-8. DvSSJ1 dsRNA Tissue Expression Levels in DP23211 Corn .................................................... 4-25

Table 4-9. IPD072Aa Protein Spectrum of Activity Bioassay Evaluation ................................................ 4-25

Table 4-10. IPD072Aa Tissue Expression Levels in DP23211 Corn ......................................................... 4-26

Table 4-11. Tillage Practice on U.S. Cropland, 2012 – 2017................................................................... 4-30

Table 4-12. Causes of Impairment in Assessed Rivers and Streams, 2020 ............................................ 4-30

Table 4-13. Animals Commonly Found in Corn Fields............................................................................ 4-43

Table 4-14. DvSSJ1 dsRNA: Tissue Expression Levels in DP23211 corn*................................................ 4-45

Table 4-15. DvSSJ1 dsRNA: Spectrum of Activity in Representative Non-Target Organisms................. 4-46

Table 4-16. IPD072Aa Tissue Expression Levels in DP23211 Corn* ....................................................... 4-48

Table 4-17. IPD072Aa Protein: Spectrum of Activity in Representative Non-Target Organisms........... 4-48

Table 4-18. Agricultural Emissions Sources............................................................................................ 4-80

Table 4-19. Emissions from Agriculture (MMT CO2–Eq)......................................................................... 4-81

LIST OF FIGURES Page

Figure 4-1. Corn Uses in the United States, 2021..................................................................................... 4-4

Figure 4-2. Corn Cultivation in the United States by County, 2021.......................................................... 4-5

Figure 4-3. Biotech Corn Traits Planted in the United States, 2020......................................................... 4-6

Figure 4-4. Conservation Tillage Practices in Corn, 2005 – 2016 ............................................................. 4-8

Figure 4-5. Pesticides Applied to Corn, 2021............................................................................................ 4-9

Figure 4-6. Glufosinate Use in the Conterminous United States – 2017................................................ 4-13

Figure 4-7. HR Weeds in the United States, 1950 – 2020 ...................................................................... 4-16

Figure 4-8. Increase in the Development of Herbicide Resistance: Herbicide Modes of Action ........... 4-16

Figure 4-9. Insecticide Use in Bt Corn Production................................................................................... 4-18

Figure 4-10. Share of Corn Acreage Planted with Stacked-Trait HR/IR Seed – 2022 ............................. 4-22

Figure 4-11. Locations and Status of U.S. Croplands Subject to Erosion................................................ 4-29

Figure 4-12. Impaired Rivers and Streams in the United States ............................................................ 4-32

Figure 4-13. Agricultural Run-Off: Mississippi River Watershed ............................................................ 4-33

Figure 4-14. Sources of U.S. Greenhouse Gas Emissions ....................................................................... 4-79
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ACRONYMS and ABBREVIATIONS

a.i. active ingredient

AOSCA Association of Official Seed Certifying Agencies

Bt bacillus thuringiensis

CAA Clean Air Act

CEQ Council on Environmental Quality

CFR Code of Federal Regulations (United States)

CO carbon monoxide

CO2 carbon dioxide

CRW corn rootworm

CWA Clean Water Act

DNA deoxyribonucleic acid 

dsRNA double stranded ribonucleic acid

dvssj1 Gene encoding for the smooth septate junction protein 1

DvSSJ1 smooth septate junction protein 1

EA Environmental Assessment

EFSA European Food Safety Agency 

EJ Environmental Justice

EO Executive Order

EPA U.S. Environmental Protection Agency

ESA Endangered Species Act of 1973

FDA U.S. Food and Drug Administration 

FFDCA Federal Food, Drug, and Cosmetic Act

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act

FONSI Finding of No Significant Impact

FQPA Food Quality Protection Act 

FWS U.S. Fish and Wildlife Service 

HR herbicide resistant

ipd072Aa gene from Pseudomonas chlororaphis encoding IDP072a protein

IPD072Aa protein for control of corn rootworm

IR insect resistant

IRM insect resistant management

IWM integrated weed management

lb pound
iv

mRNA Messenger ribonucleic acid

N2O nitrous oxide

NAAQS National Ambient Air Quality Standards

NEPA National Environmental Policy Act of 1969 and subsequent amendments

NHPA National Historic Preservation Act

NMFS National Marine Fisheries Service

NOP National Organic Program

NPS non-point source (pollution)

NRC National Research Council

NWQI National Water Quality Initiative

OECD Organization for Economic Cooperation and Development

PAT phosphinothricin N-acetyltransferase (enzyme)

pat / mo-pat gene from Streptomyces viridochromogenes that encodes the PAT enzyme 

PIP plant-incorporated protectant

PMI phosphomannose isomerase

PPRA Plant Pest Risk Assessment

PPA Plant Protection Act

RNA ribonucleic acid

siRNA small interfering ribonucleic acid

TES threatened and endangered species

TSCA Toxic Substances Control Act

U.S. United States

USDA U.S. Department of Agriculture

USDA-AMS U.S. Department of Agriculture- Agricultural Marketing Service

USDA-APHIS or 

APHIS

U.S. Department of Agriculture-Animal and Plant Health Inspection Service

USDA-ERS U.S. Department of Agriculture-Economic Research Service

USDA-NASS U.S. Department of Agriculture-National Agricultural Statistics Service

USC U.S. Code

USFWS U.S. Fish & Wildlife Service

WCR Western corn rootworm

WPS Worker Protection Standard (40 CFR part 170)
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1 PURPOSE AND NEED FOR AGENCY ACTION

1.1 Background

In July 2020, Pioneer Hi-Bred International, Inc. (Pioneer) submitted a petition (20-203-01p) to the U.S. 

Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), requesting

that DP23211 maize (corn),1 which was developed using genetic engineering, no longer be considered 

regulated under Title 7 of the Code of Federal Regulations part 340 (7 CFR part 340). As described in 

more detail below under Section 1.4–Requirement to Issue to Regulatory Status Determination, APHIS 

regulations at 7 CFR part 340 provide that any person may submit a petition to APHIS requesting that an

organism should not be regulated, and APHIS must respond to petitioners with a regulatory status 

decision.

As part of evaluation of Pioneer’s petition APHIS has developed this Environmental Assessment (EA) to 

consider the potential impacts of a determination of nonregulated status for DP23211 corn on the human 

environment.2 The primary purpose of a NEPA analysis is to ensure agencies consider the environmental 

impacts of their actions in decision making. This EA is to provide a full and fair discussion of the 

potential environmental impacts, beneficial and adverse, so as to inform decision makers and the public of 

the potential outcomes of deregulation of DP23211 corn, and ways to avoid or minimize any potential 

adverse impacts. 

This draft EA has been prepared in compliance with the National Environmental Policy Act (NEPA, 42

U.S.C. § 4321 et seq.); the Council on Environmental Quality’s (CEQ) NEPA-implementing regulations

(40 CFR parts 1500-1508); and USDA and APHIS NEPA-implementing regulations (7 CFR part 1b, and 

7 CFR part 372).

1.2 Purpose of DP23211 Corn

There are three varieties of corn rootworm in the United States that are problematic crop pests; southern 

corn rootworm (SCR; Diabrotica undecimpunctata), northern corn rootworm (NCR; Diabrotica barberi), 

and western corn rootworm (WCR; Diabrotica virgifera virgifera). Pioneer developed DP23211 corn for 

resistance to WCR, and the herbicide active ingredient (a.i.) glufosinate-ammonium.3 WCR resistance is 

conferred by DP23211 corn production of a double-stranded ribonucleic acid (dsRNA), termed DvSSJ1

dsRNA, which interferes with production of DvSSJ1 protein in WCR via RNA interference (RNAi) and 

1 Maize is the botanical term used globally for the cereal plant Zea mays. In the United States maize is commonly referred to as 

corn. Both terms are used interchangeably in this document. For consistency with the common plant name and petition APHIS 

uses the term maize, but also refers to corn in certain instances, such as in reference to food products. 2 Human environment means comprehensively the natural and physical environment and the relationship of present and future 

generations of Americans with that environment. Impacts/effects include ecological (such as the effects on natural resources 

and on the components, structures, and functioning of affected ecosystems), aesthetic, historic, cultural, economic

(such as the effects on employment), social, or health effects (40 CFR §1508.1). 3 Note that “Resistance” to herbicides is defined by the Herbicide Resistance Action Committee (HRAC) as the inherited ability 

of a plant population to survive and reproduce following repeated exposure to a dose of herbicide normally lethal to the wild 

type. “Tolerance” is distinguished from resistance and defined by HRAC as the inherent ability of a plant to survive and 

reproduce following exposure to an herbicide treatment. This implies that there was no selection or genetic manipulation to 

make the plant tolerant; it is naturally tolerant. In reference to crops developed using genetic engineering, the terms 

“resistance” and “tolerance” are often used interchangeably. Throughout this EA, APHIS will use the term “resistance” and 

“resistant”, and “herbicide-resistant” (HR), when referring to biotechnology-derived corn. 
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causes WCR death. WCR resistance is also conferred by DP23211 corn production of an insecticidal 

IPD072Aa protein. Hence, WCR resistance in DP23211 corn is conferred via two different methods; 

RNAi, and a protein toxic to WCR.

The nucleotide sequence in DvSSJ1 dsRNA is targeted to match a portion of the smooth septate junction 

protein 1 messenger RNA (mRNA) in WCR, and down-regulate expression of the DvSSJ1 protein in the 

mid-gut epithelial cells via RNAi. Smooth septate junctions are intercellular junctions unique to 

invertebrate epithelial cells that support cell to cell adhesion, contribute to the epithelial cell barrier, and 

serve other physiological functions (Faivre-Sarrailh et al. 2004; Izumi et al. 2019). When DP23211 corn 

tissue is ingested by WCR, the DvSSJ1 dsRNA results in suppression of production of DvSSJ1 protein in 

the cells of the intestinal lining—it interferes with mRNA translation. Reduction in DvSSJ1 protein 

production results in the loss of smooth septate junction and gut epithelium integrity, which is lethal to

WCR (Hu et al. 2019). 

Most current insect resistant (IR) crops—those produced using genetic engineering—utilize insecticidal 

Cry toxins derived from the soil bacterium Bacillus thuringiensis (Bt).

4 Cry toxins, when ingested by 

WCR, cause cell lysis in the mid-gut epithelium and WCR mortality (Bravo et al. 2007). IPD072Aa is 

also orally active against WCR exhibiting a similar lethal effect when ingested (Schellenberger et al. 

2016). Though its exact insecticidal mechanism of action is still under investigation, IPD072Aa appears 

to have functional similarities to Bt-derived insecticidal proteins, albeit with a differing mechanism of 

action (Schellenberger et al. 2016). Field test data show that WCR resistant to Cry3Bb1, mCry3A, and 

Cry34Ab1/Cry35Ab1 were not cross-resistant to the insecticidal activity of IPD072Aa. Thus, the ability 

of IPD072Aa to kill WCR larvae resistant to these Cry toxins implies that its mechanism of action differs 

from Cry toxins (Schellenberger et al. 2016). 

Currently, there are four Bt Cry toxins (termed plant incorporated protectants, or PIPs) that are used in IR 

crops to manage WCR; Cry3Bb1, Cry34/35Ab1, mCry3A, and eCry3.1Ab, which were registered by the 

U.S. Environmental Protection Agency (EPA) in 2003, 2005, 2006, and 2012, respectively. As with 

synthetic chemical pesticides, insects are capable of developing resistance to Cry toxins. Field-evolved 

resistance by WCR to Cry3Bb1 corn, mCry3A corn, and eCry3.1Ab corn has been documented in 

multiple Midwestern states (Gassmann et al. 2016; Jakka et al. 2016). Additionally, cross-resistance 

among Cry3Bb1, mCry3A, and eCry3.1Ab has been reported (Jakka et al. 2016). 

Sustaining the agricultural and environmental benefits of Bt based crops—the efficacy of Cry toxins—is a 

primary objective among crop producers, industry, and EPA (US-EPA 2020j). Bt Cry toxins, in the form 

of powder and sprays, are also used in organic and conventional crops for control of insect pests—Bt

preparations have been used as an insecticide in conventional crops for over 40 years. To help counter the 

development of insect resistance to Bt (Cry) toxins in transgenic crop plants the EPA has mandated the 

implementation of an Insect Resistance Management (IRM) plan for each commercially registered Bt PIP

(US-EPA 2020j). 

4 Bacillus thuringiensis (Bt) are gram-positive spore-forming bacteria that produce insecticidal proteins during the sporulation 

phase that occur as parasporal crystals (Cry proteins/toxins).
1-3

DP23211 corn is intended to diversify strategies used for WCR control through utilization of an RNAi 

based mechanism, and the IPD072Aa toxin, both of which function through mechanisms of action that 

differ from Cry toxins (Schellenberger et al. 2016; Hu et al. 2019; Pioneer 2020). The introduction of

insecticidal traits that have mechanisms of action that differ from Cry toxins is intended to provide 

growers an additional corn variety for control of WCR in corn production, and help alleviate selection 

pressure for development of Cry resistance in WCR populations.

Resistance to glufosinate-ammonium in DP23211 corn is conferred by introduction of a modified gene

(mo-pat) derived from the soil bacterium Streptomyces viridochromogenes. The mo-pat gene encodes for 

expression of the enzyme phosphinothricin acetyl transferase (PAT), which acetylates and disables the 

herbicidal activity of glufosinate-ammonium, rendering DP23211 corn resistant to the herbicide. The PAT 

protein has been previously used in biotechnology-derived varieties of corn, soybean, cotton, and canola 

crops to confer glufosinate resistance (USDA-APHIS 2022a). The herbicide-resistance trait in DP23211

corn is intended to facilitate weed management. 

1.3 Coordinated Framework for the Regulation of Biotechnology

On June 26, 1986, the White House Office of Science and Technology Policy issued the Coordinated 

Framework for the Regulation of Biotechnology (Coordinated Framework), which outlined Federal 

regulatory policy for ensuring the safety of biotechnology products. The primary federal agencies 

responsible for oversight of biotechnology products are the USDA, the U.S. Environmental Protection 

Agency (EPA), and the U.S. Food and Drug Administration (FDA). 

In 2015, the Executive Office of the President issued a memorandum directing the USDA, EPA, and FDA

to update the Coordinated Framework to clarify current roles and responsibilities in the regulation of

biotechnology products; develop a long-term strategy to ensure that the Federal biotechnology regulatory 

system is prepared for the future products of biotechnology; and commission an independent, expert 

analysis of the future landscape of biotechnology products. On January 4, 2017, the USDA, EPA, and 

FDA released an update to the Coordinated Framework (USDA-APHIS 2020b), and an accompanying 

National Strategy for Modernizing the Regulatory System for Biotechnology Products (ETIPCC 2017).

USDA-APHIS is responsible for protecting animal and plant health. USDA-APHIS regulates 

biotechnology-derived products that may pose a risk to agricultural plants and agriculturally important 

natural resources under the authorities provided by the plant pest provisions of the Plant Protection Act

(PPA), as amended (7 U.S. Code (U.S.C.) 7701–7772), and implementing regulations at 7 CFR part 340. 

The purpose of EPA oversight is to protect human and environmental health. The EPA regulates 

pesticides, including plant incorporated protectants (PIPs) that have been introduced into plants using 

genetic engineering, under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) (7 U.S.C. 

136 et seq.). In addition, the EPA regulates certain microorganisms (agricultural uses other than 

pesticides) under the Toxic Substances Control Act (15 U.S.C. 53 et seq.). The EPA also sets tolerances 

(maximum limits) for pesticide residues that may remain on or in food and animal feed, or establishes an 

exemption from the requirement for a tolerance, under the Federal Food, Drug, and Cosmetic Act 

(FFDCA; 21 U.S.C. 301 et seq.). The USDA and EPA monitor tolerances, and the FDA enforces 

tolerances—except for meat, poultry, and certain egg products that are regulated by the USDA—to ensure 

the safety of the nation's food supply (US-EPA 2020k; USDA-AMS 2020). Under its National Residue 
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Program, the USDA’s Food Safety and Inspection Service (FSIS) monitors meat, poultry, and processed 

egg products for pesticide residue and takes enforcement actions if it finds pesticide residues that exceed 

EPA tolerance levels (USDA 2020a). 

The purpose of FDA oversight is to ensure human and animal foods and drugs are safe and sanitary. The 

FDA regulates a wide variety of products, including human and animal foods, cosmetics, human and 

veterinary drugs, and human biological products under the authority of the FFDCA and Food Safety 

Modernization Act (FSMA). The FDA created the Plant Biotechnology Consultation Program in the 1992

to cooperatively work with plant developers to help them ensure foods made from their new plant 

varieties are safe and lawful (US-FDA 1992b, 2006).In this program, the FDA evaluates the safety of 

food/feed from the new crop variety before it enters the market. Although the consultation program is 

voluntary, plant developers routinely participate in it before bringing a new plant variety to market. The 

FDA completed its first plant biotechnology consultation in 1994. Thus far, the FDA has evaluated more 

than 150 new plant varieties through this program.

Amore detailed description of the roles and responsibilities of USDA-APHIS, the EPA, and FDA under 

the Coordinated Framework can be found on the USDA’s website (USDA-APHIS 2020b).

1.4 Requirement to Issue a Regulatory Status Determination

Under the authority of the plant pest provisions of the Plant Protection Act, the regulations in 7 CFR part 

340, "Movement of Organisms Modified or Produced Through Genetic Engineering,” regulate, among 

other things, the importation, interstate movement, and environmental release of organisms modified or 

produced through genetic engineering that are plant pests or pose a plausible plant pest risk.5 APHIS

recently revised 7 CFR part 340 and issued a final rule, published in the Federal Register on May 18, 

2020 (85 FR 29790-29838, Docket No. APHIS-2018-0034).

6 The final rule was implemented in 

phases. APHIS’ new Regulatory Status Review (RSR) process, which replaced the petition for

determination of nonregulated status process, became effective on April 5, 2021 for corn, soybean, cotton, 

potato, tomato, and alfalfa. The RSR process became effective for all crops as of October 1, 

2021. However, as noted in the final rule, “Until RSR is available for a particular crop...APHIS will 

continue to receive petitions for determination of nonregulated status for the crop in accordance with the 

[legacy] regulations at 7 CFR 340.6.” (85 FR 29815).

Pioneer’s petition for a determination of nonregulated status subject of this EA is being evaluated in 

accordance with the legacy regulations at 7 CFR 340.6, as it was received by APHIS in July, 2020, prior 

to full implementation of the final rule. Pursuant to the terms set forth in the final rule, any person may 

submit a petition to APHIS seeking a determination that an organism should not be regulated under 7 

CFR part 340. APHIS must respond to petitioners with a decision to approve or deny the petition. An 

organism produced using genetic engineering is no longer subject to the requirements of 7 CFR part 340 

5 Genetic engineering in the context of 7 CFR part 340 refers to biotechnology-based techniques that use recombinant, 

synthesized, or amplified nucleic acids to modify or create a genome. Various terms are used in the lay and peer review 

literature in reference to new plant varieties that have been developed using biotechnology-based techniques, these include 

“agricultural biotechnology”, “genetically engineered”, and “genetically modified”. In this EA, the terms “genetic engineering”

and “biotechnology-derived” may be used interchangeably. The term “transgenic” may also be used when discussing or 

referring to a transgene introduced into the genome of a plant. 6To view the final rule, go to www.regulations.gov and enter APHIS-2018-0034 in the Search field.
1-5

or the plant pest provisions of the PPA if APHIS determines, through conduct of a Plant Pest Risk 

Assessment (PPRA), that it is unlikely to pose a plant pest risk. 
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2 SCOPING AND PUBLIC INVOVLEMENT

APHIS seeks public comment on draft EAs through notices published in the Federal Register. On March 

6, 2012, APHIS announced in the Federal Register updated procedures for the way it solicits public 

comment on petitions for determinations of nonregulated status. Details on policy and procedures for 

public participation in the petition review and NEPA process are available in the Federal Register notice 7

 

and on the APHIS website (USDA-APHIS 2020a). 

2.1 Public Involvement for Petition 20-203-01p 

On November 3rd, 2020 APHIS announced in the Federal Register that it was making Pioneer’s petition 

available for public review and comment to help identify potential environmental and interrelated 

economic issues that APHIS should consider in evaluation of the petition.8 APHIS accepted written 

comments on the petition for a period of 60 days, until midnight, January 4th, 2021. At the end of the 

comment period APHIS had received four comments on the petition. One comment was from an 

individual, which stated opposition to biotechnology-derived (biotech) crops in general. Three comments 

were received from industry organizations, which generally supported approval of the petition. 

On April 11th, 2023 APHIS published a notice in the Federal Register that it was making the draft EA and 

draft plant pest risk assessment available for public review and comment for a period of 30 days, ending 

midnight, May 11th, 2023. At the end of the comment period APHIS had received 3 comments on the 

draft EA. One comment submitted by an individual expressed concern about the insecticidal DvSSJ1 

dsRNA targeting Western corn rootworm. Another comment by an individual expressed opposition to 

biotechnology-derived crops, in general. A comment from the Tennessee Farm Bureau Federation 

expressed support for the deregulation of DP23211 corn; approval of the petition. 

A full record of all comments received on the petition, and draft EA, is available online at 

www.regulations.gov [Docket No. APHIS-2020-0098]. APHIS considered all comments received in 

preparation of the draft and final EA. APHIS response to comments on the draft EA, specifically, and 

development of the final EA, are provided in Appendix 2.

2.2 Issues Considered in this EA

APHIS developed a list of topics for consideration in this EA based on issues identified in public 

comments on the petition, public comments submitted for other EAs and Environmental Impact 

Statements (EISs) evaluating petitions for nonregulated status, prior EAs/EISs for biotechnology-derived

corn varieties, the scientific literature on agricultural biotechnology, and issues identified by APHIS 

specific to wild and cultivated Zea and Tripsacum species. The following topics were identified as 

relevant to the scope of the impacts analysis in this EA (40 CFR § 1501.9–Scoping): 

7 Federal Register, Vol. 77, No. 44, Tuesday, March 6, 2012, p.13258 – Biotechnology Regulatory Services; Changes 

Regarding the Solicitation of Public Comment for Petitions for Determinations of Nonregulated Status

for Genetically Engineered Organisms [http://www.gpo.gov/fdsys/pkg/FR-2012-03-06/pdf/2012-5364.pdf] 8 Federal Register, / Vol. 85, No. 213 / Tuesday, November 3, 2020, p. 69564. Pioneer Hi-Bred International, Inc.; Availability of a 

Petition for the Determination of Nonregulated Status for Insect Resistant and Herbicide Tolerant Maize [Docket No. APHIS–

2020–0098]. Available at https://www.federalregister.gov/documents/2020/11/03/2020-24267/pioneer-hi-bredinternational-inc-availability-of-a-petition-for-the-determination-of-nonregulated
2-2

• Agricultural Production: Acreage and areas of corn production, agronomic practices and inputs

• Physical Environment: Soils, water resources, air quality

• Biological Resources: Soil biota, animal communities, plant communities, gene flow and 

weediness, biodiversity

• Public health and worker safety

• Food animal health and welfare

• Domestic economy and international trade

• Potential impacts on threatened and endangered species 

• Compliance of the Agency’s regulatory status decision with Executive Orders, and 

environmental laws and regulations to which the action is subject.

Because the introduced genes are involved in insect pest and weed management, the primary focus of this 

EA is on: (1) insect and insect resistance management, (2) weed and herbicide resistant weed 

management, (3) potential effects of exposure to the introduced trait genes and gene products on human 

health and wildlife, and (4) gene flow and potential weediness of DP23211 corn.
3-1 

3 ALTERNATIVES

NEPA implementing regulations (40 C.F.R. 1500 – 1508) require agencies to evaluate alternatives to the 

proposed action that would avoid or minimize adverse impacts, or enhance the quality of the human 

environment, while meeting the purpose and need for the Agency’s action (in this case, a regulatory 

decision). Two alternatives are evaluated in this EA: (1) No Action, denial of the petition, and (2) 

Preferred Alternative, approval of the petition. 

3.1 No Action Alternative: Deny the Petition Request

One of the alternatives that APHIS considers is a “No Action Alternative”. APHIS discusses this 

alternative as required by CEQ NEPA implementing regulations at 40 CFR § 1502.14. Under the No 

Action Alternative APHIS would deny the petition request for nonregulated status and DP23211 corn 

would remain regulated under 7 CFR part 340. Permits issued by APHIS would be required for the 

environmental release or shipment of DP23211 corn. Because APHIS concluded in its PPRA that 

DP23211 corn is unlikely to pose a plant pest risk (USDA-APHIS 2022b), denial of the petition would 

not be a scientifically nor legally sound response as it would not meet the purpose and need in providing a 

science based regulatory status decision to the petitioner, pursuant to 7 CFR part 340. 

3.2 Preferred Alternative: Approve the Petition–Issue a Determination of

Nonregulated Status for DP23211 Corn 

Under this alternative APHIS would approve the petition and DP23211 corn would no longer be subject 

to regulation under 7 CFR part 340. APHIS permits would no longer be required for the environmental 

release or shipment of DP23211 corn. Because it was determined that, based on the scientific evidence 

before the Agency, DP23211 corn is unlikely to pose a plant pest risk (USDA-APHIS 2022b), this 

alternative satisfies the purpose and need to respond to the petition for nonregulated status with a science 

based regulatory status decision, pursuant to the requirements of 7 CFR part 340, and the Agency’s 

statutory authority under the PPA. 

3.3 Summary of the No Action and Preferred Alternative Analyses

Table 3-1 presents a summary of the environmental impacts associated with the No Action Alternative 

and Preferred Alternative that are evaluated in this draft EA. Detailed analysis of the affected 

environment and environmental impacts is discussed in Chapter 4. 

Table 3-1. Summary of Potential Impacts for the Alternatives Considered

Analysis No Action Alternative: Deny the 

Petition Request

Preferred Alternative: Approve the 

Petition for Nonregulated Status for 

DP23211 Corn

Meets Purpose and Need No Yes

Management Practices

Acreage and Areas of Corn 

Production

Denial of the petition would have no 

effect on the areas or acreage utilized 

for corn production. Regulated field 

trials would be conducted on lands 

allocated for this purpose.

Approval of the petition is unlikely to have 

any effect on an increase or decrease in 

total U.S. corn acreage. DP23211 corn, if 

adopted by growers, would be expected to 

replace other insect resistant (IR) and 

herbicide resistant (HR) corn varieties 
3-2 

Analysis No Action Alternative: Deny the 

Petition Request

Preferred Alternative: Approve the 

Petition for Nonregulated Status for 

DP23211 Corn

currently cultivated, as opposed to 

augmenting current corn crops.

Agronomic Practices and 

Inputs

Agronomic practices and inputs used 

in corn crop production, to include 

regulated field trials, would remain 

unchanged. Denial of the petition 

would have no effect on insect and 

weed management in corn.

Agronomic practices and inputs would be 

similar to other varieties of corn. DP23211 

corn would facilitate use of glufosinateammonium, in lieu of other herbicides. 

Thus, adoption of DP23211 corn could 

entail increased use of glufosinateammonium in the United States, with a 

decrease in use of other herbicides with 

similar spectrums of weed control. As an IR 

corn variety comprised of plant 

incorporated protectants (PIPs) with 

specify for western corn rootworm (WCR), 

cultivation of DP23211 would likely entail 

less use of soil- and foliar-applied

insecticides to control WCR. Because the 

DvSSJ1 dsRNA and IPD072Aa protein 

provide novel mechanisms of action for 

control of WCR, DP23211 corn may also 

prove useful in helping deter development 

of Bt Cry resistant WCR pest populations, 

and sustaining the efficacy of current and 

future Bt Cry based IR crops.

Use of Biotechnology-Derived 

Corn 

Denial of the petition would have no 

effect on grower choice in the 

planting of biotechnology-derived or 

conventionally bred corn. 

Approval of the petition would provide for 

cultivation of a corn variety resistant to 

WCR, an economically damaging insect 

pest, and the herbicide active ingredient 

glufosinate-ammonium. These traits are 

expected to facilitate insect pest and weed 

management. 

Physical Environment

Soil Quality Agronomic practices and inputs 

associated with corn production 

potentially impacting soils, to include 

regulated field trials, would continue 

along current trends.

The agronomic practices and inputs are 

similar for both DP23211 corn and

conventional corn varieties. Because 

DP23211 corn production could facilitate 

less insecticide use (~11% per crop cycle), 

potential impacts on soils could be 

potentially reduced, relative to non-IR corn 

varieties.

Water Resources Denial of the petition would have no 

effect on water resources in the 

United States. Regulated field trials 

are limited on a spatiotemporal scale, 

and present negligible risks to water 

resources. 

Because the agronomic practices and 

inputs utilized for DP23211 corn 

production would be similar, sources of 

potential impacts on water resources, 

namely NPS pollutants in agricultural runoff, would not be expected to substantially 

differ. Any reduced insecticide use would 

reduce the risk of insecticides in run-off. 

The EPA provides label use restrictions and 
3-3 

Analysis No Action Alternative: Deny the 

Petition Request

Preferred Alternative: Approve the 

Petition for Nonregulated Status for 

DP23211 Corn

guidance for pesticides, to include 

glufosinate based herbicides, that are 

intended to be protective of surface water 

and groundwater.

Air Quality Emission sources, namely tillage and 

machinery combusting fossil fuels, 

and the level of emissions associated 

with corn production, to include 

regulated field trials, would be 

unaffected by denial of the petition.

Because the agronomic practices and 

inputs used for DP23211 corn production

would be similar to conventional corn, and 

acreage would remain unchanged, 

significant changes to emission sources nor 

level of emissions are not expected. There 

would be minor reductions in National 

Ambient Air Quality Standards (NAAQS) 

emissions as a result of reduced insecticide 

applications. 

Biological Resources

Soil Biota Potential impacts of corn 

production/regulated field trials on 

soil biota would continue along 

current trends.

Commercial production of DP23211 corn or 

progeny is not expected to present any 

risks to soil biota. The introduced HR/IR 

transgenes and gene products are not 

expected to have any effects on the longterm viability and function of soil biota or 

community structures. 

Animal Communities Regulated field trials of DP23211 corn 

would present negligible risk to 

animal communities.

Approval of the petition, and subsequent 

commercial production of DP23211 corn, 

would not be expected to affect animal 

communities adjacent to or within 

DP23211 corn cropping systems any 

differently from that of current corn 

cropping systems. The DvSSJ1 dsRNA, and 

IPD072Aa, PAT, and PMI proteins do not 

pose any hazard to wildlife.

Plant Communities Regulated field trials of DP23211 corn 

would present negligible risks to plant 

communities in proximity to DP23211 

corn fields.

Because the agronomic practices and 

inputs that will be used for DP23211 corn 

production are similar, save for reduced 

insecticide use, potential impacts on plant 

communities would be similar as for other 

corn varieties currently cultivated. The EPA 

regulates and determines the use of 

glufosinate. Pesticide use requirements are 

intended to be protective of non-target 

plant communities, such as those in 

adjacent fields. 

Gene Flow and Weediness Tripsacum species are the only 

sexually compatible plants found in 

the United States. The potential for 

corn (Zea mays) to hybridize with wild 

relatives of Tripsacum is low; 

hybridization and successful 

introgression of Z. mays genes into 

DP23211 corn, if grown for commercial 

purposes, would be cultivated as are 

current corn varieties and present the 

same potential risk for gene flow, 

specifically the propensity for and 

frequency of gene flow, as current corn 

varieties. Conceptually, the IR trait could 
3-4 

Analysis No Action Alternative: Deny the 

Petition Request

Preferred Alternative: Approve the 

Petition for Nonregulated Status for 

DP23211 Corn

Tripsacum is rare (de Wet and Harlan 

1972; de Wet et al. 1978; Eubanks 

1995). Gene flow to Tripsacum

species during regulated fields trials 

of DP23211 corn is highly unlikely.

confer a competitive advantage to wild 

Tripsacum species. While conceptually 

possible, the likelihood of Tripsacum

populations comprising the IR trait genes 

developing is considered unlikely. First, the 

potential for hybridization and successful 

introgression of Z. mays genes into 

Tripsacum populations is remote (de Wet 

and Harlan 1972; de Wet et al. 1978; 

Eubanks 1995). Successful introgression of 

Zea mays genes into Tripsacum

populations, successful gene flow in this 

direction, has not been observed in the 

wild (USDA-APHIS 2007; FAO 2014b)). 

Second, while corn pollen can travel as far 

as 1⁄2 mile (800 m) in 2 minutes in a wind 

of 15 miles per hour (27 km/h) (Nielsen 

2016), most pollen is deposited within a 

short distance of the corn plant. Numerous 

studies show the majority (84-92%) of 

pollen grains travel less than 16 feet (5 

meters) (Pleasants et al. 2001). At a 

distance of 200 feet (60 m) from the corn 

plant, the pollen concentration averages 

only about 1%.

Biodiversity Denial of the petition, and any 

regulated field trials of DP23211 corn, 

would present negligible risks to 

biodiversity in an around DP23211 

corn crops.

Commercial production of DP23211 corn 

would affect biodiversity in and around 

DP23211 corn crops no differently than 

other corn cropping systems. The DvSSJ1 

dsRNA, and IPD072Aa, PAT, and PMI 

proteins are unlikely to present any hazards

to plant, animal, fungal, or bacterial 

communities. All pesticide use would be 

subject to EPA registration and use 

requirements.

Human and Animal Health

Human Health and Worker 

Safety 

Denial of the petition would have no 

effect on human health. DP23211

corn would remain regulated and 

would not be available for food uses.

Approval of the petition would provide for 

the use of DP23211 corn products in the 

food and feed industries. Pioneer 

completed a food safety consultation with 

the FDA in 2022; the FDA had no questions 

concerning human food derived from 

DP23211 corn (US-FDA 2022). The EPA’s 

regulation of pesticides, and worker 

protection standards, would remain 

unchanged.

Animal Health and Welfare Denial of the petition would have no 

effect on animal health and welfare. 

DP23211 corn would remain 

DP23211 corn would provide for animal 

feed products. Pioneer completed a an 

animal feed safety consultation with the
3-5 

Analysis No Action Alternative: Deny the 

Petition Request

Preferred Alternative: Approve the 

Petition for Nonregulated Status for 

DP23211 Corn

regulated and would not be available 

for feed uses.

FDA in 2022; the FDA had no questions 

concerning feed derived from DP23211 

corn (US-FDA 2022).

Socioeconomic

Domestic Economy Denial of the petition would preclude 

DP23211 corn being available for 

food, feed, and fuel uses. This, 

however, would have no effect on 

domestic markets. 

DP23211 corn, a field (dent) corn variety, is 

expected to be used for provision of 

standard corn-based food, feed, fuel, and 

industrial products. The potential impacts 

of DP23211 corn on domestic markets 

would be considered largely beneficial. 

DP23211 corn would provide farmers with 

an additional option for management of 

CRW pests and protection of corn grain 

yield. From 1996-2018, IR corn targeting 

corn boring pests provided a 7% increase in 

yield, and increased farm income of $81/ha 

($32.8/acre). IR corn targeting CRW 

provided a 5% increase in yield, and 

increased farm income of $78/ha 

($31.6/acre) (Brookes and Barfoot 2018c). 

Aggregate U.S. farm income benefit from 

1996-2018 for IR corn was $45.6 billion 

(Brookes and Barfoot 2018c). In 2018, the 

global gross farm income gains from using 

IR corn was $4.53 billion (Brookes and 

Barfoot 2018c).

International Trade Denial of the petition would have no 

impacts on the trade of corn 

commodities.

Approval of the petition is unlikely to have 

a substantial effect on the trade of U.S. 

corn commodities. 

Coordinated Framework

U.S. Regulatory Agencies Denial of the petition would have no 

effect on the roles of the FDA and 

EPA in the oversight of DP23211 corn.

As cited above Pioneer consulted with the 

FDA on the food and feed safety of 

DP23211 corn. Glufosinate and other 

pesticide use will be subject to EPA 

registration and label use requirements. 

Regulatory and Policy Compliance

ESA, CWA, CAA, SDWA, 

NHPA, EOs

Fully compliant (*not compliant with 

the Plant Protection Act (PPA) and 7 

CFR part 340)

Fully compliant
4-1

4 AFFECTED ENVIRONMENT AND ENVIRONMENTAL 

CONSEQUENCES

4.1 Scope of Analysis

Evaluation of the Potential Impacts of Agency Action

An impact would be any change, beneficial or adverse, from existing (baseline) conditions described for 

the affected environment. Thus, impacts/effects means changes to the human environment that could 

result from approval of the petition, subsequent commercial production of DP23211 corn, and market 

utilization of commodities derived from this variety. 

Pursuant to CEQ regulations (40 CFR § 1508.1(g)), impacts/effects considered are those that are 

reasonably foreseeable and have a reasonably close causal relationship to the petition decision. 

Impacts/effects may occur soon after the Agency decision or occur later in time. Potential impacts/effects 

include ecological (such as effects on the components and functioning of ecosystems), historic, cultural, 

social, economic, and effects on human health. Impacts/effects include those resulting from actions that 

may have both beneficial and detrimental effects.

In considering whether the effects of the proposed action are significant, agencies are to analyze the 

potentially affected environment, and degree of the effects of the action in relation to the affected 

environment (40 CFR § 1501.3). Agencies should also consider connected actions consistent with 40 

CFR§ 1501.9(e)(1). The potentially affected environment (summarized below) is defined by the area(s) 

potentially impacted by the proposed action (e.g., national, regional, or local), and associated resources 

(e.g., natural, cultural). In considering the degree of the effects, agencies are to consider the following, as 

appropriate to the proposed action:

• Short- and long-term effects

• Both beneficial and adverse effects

• Effects on public health and safety

• Effects that would violate federal, state, tribal, or local laws protecting the environment

Potentially Affected Environment

The potential impacts of commercial production of a biotechnology-derived crop on the human 

environment occur within the context of agriculture’s general contribution to environmental change (NRC 

2010). Crop production has historically converted biologically diverse natural grasslands, wetlands, and 

native forests into less diverse agroecosystems to produce food, feed, fiber, and fuel sufficient to meet 

societal needs. Potential effects on the environment depend on the intensity and scale of crop production

over time, the agronomic inputs applied (e.g., fertilizers, pesticides, irrigation water), and the effective 

management of inputs, pests, weeds, and tillage. Corn is used to produce a variety of food products, 

animal feed, fuel ethanol, and a wide range of industrial products. There are around 90 million acres of 

land area in the United States planted to corn, and 323 to 340 million acres of total U.S. cropland planted 

on annual basis. Thus, the scale of potential impacts, namely in an aggregate sense, requires integration of 

crop production with sustainability and mitigation practices, for both biotechnology based and 

conventional corn cropping systems. In general, tillage, crop monoculture, and fertilizer and pesticide 
4-2 

inputs can potentially have adverse effects on topsoil, water quality, air quality, and local biodiversity.

Agriculture is a leading cause of water-quality impairment in the United States as a result of run-off crop 

protection/production inputs (US-EPA 2020a). No-tillage systems, crop rotations, cover cropping, 

integrated pest and weed management, and other environmentally beneficial practices can help ameliorate 

some of the adverse impacts, although a tradeoff between the agricultural production food, feed, fiber, 

and fuel, and some degree of environment impacts, will always remain (Robertson and Swinton 2005). 

Gene flow, movement of a transgene to sexually compatible species, has also been a topic of concern with 

transgenic crops, more so in terms of potential economic, as opposed to ecological impacts. For corn, 

gene flow to wild relative species has not been an issue to date because sexually compatible relatives of 

corn do not exist in the United States. However, gene flow of transgenic traits in corn into non-modified

corn varieties, or other transgenic corn varieties, is a concern for farmers and markets that depend on 

adhering to strict identity preservation standards for certain food and feed commodities. Such gene flow 

can result in adverse economic impacts to the transgenic trait-sensitive market. 

Due to the scale of crop production in the United States (e.g., 300 to 330 million acres planted with

principal on an annual basis), developing and implementing environmentally sound, sustainable 

agricultural management practices is a primary goal of federal and state programs—applicable to 

biotechnology-based, conventional, and organic cropping systems alike (e.g., (USDA-NRCS 2015; USEPA 2020h; USDA-NRCS 2020a), and others). 

It is within this context that APHIS evaluates the potential impacts of DP23211 corn on the human 

environment if deregulated, and cultivated on a commercial scale for corn based commodities. 

DP23211 Corn: Assumptions used in Analysis

It assumed that, in the event Pioneer’s petition is approved, DP23211 corn would be grown for production 

of food, feed, fuel, and industrial commodities. It is also assumed that the only potential impacts that 

could derive from production and marketing of DP23211 corn that could be considered unique, as 

compared to other corn varieties, are relative to the trait genes and gene products (Table 4-1). DP23211 

corn would provide insect resistance traits, and facilitate weed management with the use of glufosinate–

ammonium based herbicides. 

Table 4-1. Summary of Genetic Elements in DP23211 Corn

Genetic 

Element 

Description Origin Species Occurrence

pmi Phosphomannose 

isomerase gene

Escherichia coli Soils, foods, and intestines of animals

mo-pat Maize-optimized 

phosphinothricin 

acetyltransferase gene

Streptomyces 

viridochromogenes

Soil bacterium

DvSSJ1 Fragment of the smooth 

septate junction protein 1 

(dvssj1) gene

Diabrotica virgifera 

virgifera (western corn 

rootworm)

Ubiquitous throughout the United 

States 

ipd072Aa Insect protection gene Pseudomonas chlororaphis Soil bacterium
4-3

4.2 No Action Alternative: Deny the Petition Request

Because APHIS concluded in its PPRA that DP23211 corn is unlikely to pose a plant pest risk (USDAAPHIS 2022b), denial of the petition for nonregulated status would be inconsistent with the Agency’s 

statutory authority under the plant pest provisions of the PPA, implementing regulations at 7 CFR part 

340 (as discussed in 1.4 – Requirement to Issue a Regulatory Status Determination), and federal policies 

embodied in the Coordinated Framework. Because it would be unreasonable to implement an alternative 

absent any jurisdiction to do so, this alternative is not a practicable option. 

While implementing the No Action alternative is not feasible, APHIS provides a summary evaluation for 

denial of the petition—where DP23211 corn would be regulated under 7 CFR part 340 and require 

APHIS authorization for importation, interstate movement, or release into the environment. 

APHIS’ regulation of DP23211 corn, which would effectively preclude commercial production of this 

variety, would have no effect on the acreage used for U.S. corn production, nor the current practices and 

inputs used for the commercial production of corn. Likewise, denial of the petition would have no effect 

on the physical environment, biological resources, human or animal health, or domestic or international 

corn markets. Any field testing or interstate movement of DP23211 corn would require APHIS 

authorization, which would be provided via permit, pursuant to 7 CFR part 340, described in more detail 

below. For both permits, APHIS Biotechnology Regulatory Services prescribes criteria and conditions 

that must be met in order to ensure that the regulated plant is introduced in such a way that it is not 

inadvertently released beyond the proposed introduction site, and it or its progeny do not persist in the

environment. Applicants submit documents for releases, such as design protocols, that address how the 

required conditions will be met. Permit applicants must describe how developers will perform field 

testing, including specific measures to keep the regulated organism confined to the authorized field site 

and measures to ensure that it does not persist after completion of the field test. The permitting provisions 

found in 7 CFR part 340 describe the information required for permit applications, the standard permit 

conditions, and administrative information. Standard permit conditions are listed in the regulation, and 

APHIS can supplement these with additional conditions or requirements, as necessary.

Actions taken by APHIS on permit applications are subject to NEPA. APHIS ensures compliance of 

permits issued with NEPA, and CEQ and USDA implementing regulations. 9 Issuance of permits are 

typically authorized under a categorical exclusion from the requirement to conduct an EA or EIS, 

consistent with APHIS’ NEPA implementation regulations (7 CFR part 372). APHIS conducts EAs or 

EISs for permits as applicable to the permit request. This process complies with CEQ and USDA 

regulations for implementing NEPA.

There are no impacts on the human environment that would derive from denial of the petition. To the 

extent individuals comply with APHIS permit requirements, EPA requirements for pesticide use, and 

ESA requirements, there would be little risk of harm to wildlife or natural resources as a result of APHIS 

authorized field testing of DP23211 corn. Interstate movement of DP23211 corn would present negligible 

environmental risks. 

9 CEQ regulations for implementing NEPA at 40 CFR 1500; USDA regulations implementing NEPA at 7 CFR part 1b; and APHIS 

regulations at 7 CFR part 372.
4-4

4.3 Preferred Alternative: Approve the Petition Request

4.3.1 U.S. Corn Production

4.3.1.1 Acreage and Area of U.S. Corn Production

There are three primary varieties of corn cultivated in the United States: Dent (or field) corn (Zea mays 

var. indenata), sweet corn (Zea mays var. saccharata), and popcorn (Zea mays var. everta). To a lesser 

extent flour (Zea mays var. amylacea) and waxy corn (Zea mays var. ceratina) varieties are produced.

Corn varieties are differentiated by the starch, protein, oil, water, or other properties of the kernel, and 

produced for specific uses; e.g., food, animal feed, industrial products.

DP23211 corn is a dent corn variety (Oestreich 1993; Pioneer 2020). Dent corn, at maturity, has an 

obvious depression (or dent) at the crown of the kernels—thus its name. Dent corn is primarily used for 

animal feed and fuel ethanol stock, and comprises the bulk of U.S. production, in excess of 90% of corn 

acres annually. Among dent corn commodities, animal feed accounts for around 38% – 48% of use, and

stock for the production of fuel ethanol for around 25% – 35%, on annual basis (NCGA 2022). The 

remainder is processed into a variety of food and industrial products such as starch, sweeteners, corn oil

and corn syrup, and beverage and industrial alcohol (Figure 4-1).

Figure 4-1. Corn Uses in the United States, 2021

Corn has food, seed, and industrial uses (FSI). Note that feed is comprised of grain, and distillers' dried grains with 

solubles (DDGS). Feed for both dairy and beef has been the primary use of DDGS, but increasingly larger quantities 

of DDGS are making their way into the feed rations of hogs and poultry. The statistics/percent allocations of corn, 

provided here for 2020, vary slightly on an annual basis. Source: (PRX 2019; USDA-ERS 2019; NCGA 2020)

Over the last ten years around 85 to 95 million acres of dent corn have been harvested in the United States

on an annual basis (USDA-NASS 2019a). This comprises approximately 25% of total U.S. cropland).

Production of popcorn comprises around 0.2 million acres, and sweet and waxy corn around 0.5 million 

acres, each, on an annual basis (< 1% of corn acreage on an annual basis). While dent corn can be grown 

in all states to some extent, the majority of commercial production occurs in the Corn Belt, generally 

defined as Illinois, Iowa, Indiana, southern and western Minnesota, eastern South Dakota and Nebraska, 
4-5

western Kentucky and Ohio, and the northern two-thirds of Missouri. The leading dent corn-producing 

states of Illinois, Iowa, and Nebraska account for approximately 40% of the annual U.S. harvest.

Substantial production also occurs in Idaho, California’s Central Valley, along the Mississippi River, and 

up the Eastern Seaboard from Georgia to Upstate New York (Figure 4-2). 

Figure 4-2. Corn Cultivation in the United States by County, 2021

Source: (USDA-NASS 2021)

Around 93% of the corn produced in the United States is comprised of biotechnology-derived varieties

(Figure 4-3), the majority of this dent/field corn, with limited quantities of biotech sweet corn being 

grown. Only about 1% of the corn grown in the United States is sweet corn—that consumed as canned, 

frozen, or fresh ears—and of that, only about 10% of sweet corn acreage is comprised of biotech varieties

(Reiley 2019). Most corn varieties are stacked-trait herbicide-resistant (HR) and insect-resistant (IR). 

Stacked-trait varieties with HR and IR traits accounted for 81% of the 2021 crop. Only 9% contained a 

single HR trait, and 3% a single IR in 2021. Of the ~90 million corn acres planted in 2021, around 7.3

million were conventionally bred. 
4-6

Figure 4-3. Biotech Corn Traits Planted in the United States, 2020

Source: (NCGA 2022)

In addition to the varieties described, there are around 12,000 acres of traditional or Indian corn produced 

in the United States, primarily on Indian reservations (USDA-NASS 2020b). Traditional or Indian corn is 

an open-pollinated (nonhybrid), non-biotech cultivar of Zea mays that was indigenously developed and 

consists of many heritage varieties of sizes, color, and drought tolerance. Traditional corn grown on 

southwest reservations has been passed from generation to generation through seed saving by American 

Indian and Hispanic communities. Traditional or Indian corn is culturally significant; it is reported to be 

grown in all states except Alabama, Michigan, Missouri, Montana, Nebraska, South Dakota, Vermont, 

Virginia, and West Virginia. 

4.3.1.2 Agronomic Practices and Inputs

Commercial corn production utilizes a variety of agronomic practices and inputs that aim to achieve 

optimal yield, product quality, and grower net returns. These include the occasional or regular application 

of manure or synthetic fertilizers; pesticides; tillage; crop rotation; and cover crops. Some of these

practices (e.g., tillage) and inputs (e.g., fertilizers, pesticides) can, when applied in excess or improperly, 

present challenges in maintaining air, soil, and water quality. Pesticide and fertilizer use can also present 

risks to wildlife and human health. The relationship between these practices and inputs and air, soil, and 

water quality, biological resources, human health, as well as the socioeconomic aspects of corn 

production, are discussed in the subsequent sections of this chapter. 
4-7 

Apart from the herbicide-, insect-, or disease-resistant trait(s), there are little differences in the agronomic 

practices and inputs used for biotech and conventionally bred crops. HR crops will influence the types of 

herbicides used. IR crops generally require less insecticide use, and disease resistant crops the use rates of 

fungicides and similar chemicals targeting plant pathogens. The agronomic practices, and current uses of 

the herbicides that will be used with DP23211 corn, are summarized below. 

4.3.1.2.1 Agronomic Practices

Growers employ several practices for the management of plant pests and weeds, summarized below

(Table 4-2). Among these, tillage is a practice that can have environmental impacts, and this topic, in 

relation to HR/IR corn, is discussed in more detail below.

Table 4-2. Top Practices in Pest Management, 2018 Crop Year

Practice % of corn planted acres

Monitoring: Scouted for weeds 94

Avoidance: Rotated crops during last three years 84

Prevention: Used no-till or minimum till 65

Suppression: Maintained ground cover, mulched, or used other physical 

barriers

45

Source: (USDA-NASS 2019c)

4.3.1.2.1.1 Tillage

Tillage is used to control weeds, soil-borne pests and disease, and prepare the seedbed. Tillage types are 

classified as conventional, reduced, and conservation tillage (e.g., no-till and mulch-till), which are 

characterized by the amount of plant material left on the field after harvest and the degree of soil 

disturbance they cause (Harper 2017). Conventional tillage involves intensive plowing leaving less than 

15% crop residue in the field; reduced tillage leaves 15% to 30% crop residue; and conservation tillage, 

such as mulch-till, involves leaving at least 30% of crop residue. No-till systems leave all crop residue on 

the field (Claassen et al. 2018; OSU 2019). 

Decisions concerning the amount, timing, and type of tillage to employ involve consideration of a wide 

range of interrelated factors such as the variety and extent of weeds and soil borne crop pests present, soil 

erosional capacity, fuel and other input costs, anticipated weather patterns, and potential air and water 

quality issues. Over the long-term conventional tillage impairs soil quality and results in soil erosion and 

run-off that can adversely affect surface waters (Wallander 2015). Conservation tillage systems are the 

least intensive and, as the name implies, aim to conserve topsoil and soil quality. Conservation tillage 

provides a variety of agronomic and economic benefits, such as preservation of soil organic matter, 

reductions in soil erosion and water pollution, as well as reductions in fuel use and crop production costs

(Claassen et al. 2018). However, conservation tillage, especially no-till, can also cause production 

problems such as increased soil compaction, perennial weeds or weed shifts, buildup of plant pathogens 

or pests in crop residue, and slow early crop growth due to cooler soil temperatures (Roth 2015). A 

systematic use of crop rotations can facilitate the benefits of conservation tillage by eliminating some of 

the stresses observed in continuous no-till crops (Roth 2015). 

The adoption of conservation tillage systems increased steadily throughout the 1980s and 1990s and 

continues to do so. While approximately 33% of corn acres were produced using conservation tillage 
4-8

systems in 1990, 65% of corn acres were produced using conservation tillage systems in 2016 (Claassen 

et al. 2018). No-till accounted for around 42% of conservation tillage in 2016 (27% overall) (Figure 4-4).

In part, an increase in conservation tillage was facilitated by the availability (since the 1980s) of postemergent herbicides (Fernandez-Cornejo et al. 2012), which can be applied throughout the growing 

season—not just before planting, as had previously been the case. Another factor has been the 

implementation of soil conservation programs that began in the mid-1980s, which encourage/incentivize

conservation tillage practices to help conserve soils (USDA-NRCS 2006). Continued increases in 

conservation tillage since the late 1990s have also been attributed to the use of herbicide resistant crops, 

which can facilitate the chemical control of weeds and reduce the need for mechanical weed control 

(Towery and Werblow 2010; USDA-ERS 2012). 

Figure 4-4. Conservation Tillage Practices in Corn, 2005 – 2016

Source: (Claassen et al. 2018)

4.3.1.2.2 Agronomic Inputs

In addition to the agronomic practices described, chemical inputs for control of insect pests, nematodes, 

pathogens, weeds, and the addition of plant nutrients to soils are an integral aspect of corn production—

biotech, conventionally bred, and organic cropping systems alike. These inputs are used to maximize

yield, product quality, and grower net returns. Agronomic inputs relative to DP23211 corn production are 

discussed following. 

4.3.1.2.2.1 Fertilizers

Since 1975, the majority of corn acreage has been treated with nitrogen, phosphate, and potash

(potassium), and about a third of planted acres treated with sulfur. Inputs for the 2018 crop year (latest 

data) are provided in (Table 4-3). Soils in many areas of the United States where corn is produced are 

naturally deficient in nitrogen, phosphorus, and other nutrients, requiring fertilizer inputs, to include 

manure, to produce the crop yields necessary to meet market demand. Given the importance of nutrient 

availability to corn growth, fertilization with nitrogen, phosphorus, and potassium is practiced widely in 

the United States. While nitrogen and phosphorus are important agricultural inputs, the application of 

amounts exceeding recommended thresholds can have adverse effects on air and water quality (discussed 

in Section 4.3.2–Physical Environment).
4-9 

Table 4-3. Fertilizer Applied to Corn Acres, 2021 Crop Year

 Fertilizer % of Planted Acres Avg. Rate for Year 

(lbs/acre) 

Total Applied 

(billion lbs)

Nitrogen (N) 95 150 12.3

Phosphate (P2O5) 75 64 4.1

Potash (K2O) 65 77 4.3

Sulfur (S) 34 19 0.5

Source: (USDA-NASS 2022b)

4.3.1.2.2.2 Pesticides 

Pesticides contribute to higher yields and product quality by controlling weeds, insect pests, nematodes, 

and plant pathogens. Herbicides, in particular, reduce the amount of labor and time required for the 

manual/mechanical control of weeds. Plant incorporated protectants providing insect resistance, such as 

the IR traits in DP23211 corn, can likewise reduce labor, as well as fuel and synthetic chemicals costs. 

Common corn pests include beetles (Coleoptera species), moth and butterfly larvae (Lepidoptera

species), pathogenic fungi (e.g., corn leaf blight), bacteria (e.g., stalk rot), and viruses (e.g., dwarf mosaic 

virus) (UMinn 2019). Numerous populations of weed species across the United States require annual 

management in corn cropping systems (Jhala et al. 2014). In corn production, herbicides are the most 

widely used, followed by fungicides and insecticides (Figure 4-5), exemplary of the significance of weed 

control in corn production. Because DP23211 corn is resistant to glufosinate-ammonium and WCR, 

emphasis in this EA is given to glufosinate use and weed and weed resistance management, and insect 

pest and insect resistance management, discussed in the following sections. 

Figure 4-5. Pesticides Applied to Corn, 2021

Source: (USDA-NASS 2022b) 

4.3.1.2.2.3 Weed and Herbicide Resistant Weed Management 

There are around 50 species of weeds among U.S. cornfields (Jhala et al. 2014). Currently, there are 

around 23 species that are particularly problematic due to herbicide resistance (Heap 2020). Weeds have 

been and will remain a problem in corn crop production, especially in the early part of the growing 

96

19

14

1

0 10 20 30 40 50 60 70 80 90 100

Herbicide

Fungicide

Insecticide

Other

Pesticides Applied to Corn Acres, 2021 Crop Year 

(% of planted acres)
4-10

season, due to the slow early growth rate of corn and wide row spacing (Jhala et al. 2014). Their presence 

can reduce yields and product quality, increase harvest costs, and reduce net economic returns by:

• increasing insect and disease damage in crops by serving as hosts for pests and pathogens;

• reducing seedbed soil moisture and structure as a result of increased tillage needed to kill weeds 

prior to seeding;

• increasing dockage with higher cleaning and transportation costs; and

• contamination, resulting in reduced grades and quality from similar inseparable size and shape 

weed seeds (cleavers, for example).

Exemplary of the potential impact of weeds on yield and net returns: On average, weeds cause 52% corn 

yield loss when using BMPs but no herbicidal weed control. More than half of corn production and value

across North America would potentially be lost with weeds left uncontrolled (Page et al. 2012; Dille et al. 

2015; Soltani et al. 2017). One study found that, averaged across seven years, weed interference in corn in 

the United States and Canada caused a 50% yield loss, which equates to a loss of 148 million tons of corn 

grain valued at over $26.7 billion annually (Soltani et al. 2017). Other studies have found that U.S. corn 

yield loss from weed interference can range as high as 15% with weed control (Bridges 1992; WSSA 

2020).

Weed Management with Herbicide Resistant Corn 

Prior to the development of chemical herbicides farmers controlled weeds by tillage, hoeing or pulling by 

hand, mowing, site selection, crop rotation, and use of crop seed free of weed seeds. U.S. farmers began 

widescale adoption of chemical herbicides after their commercial introduction in the 1950’s because they 

were inexpensive, effective, easy to apply, reduced labor costs, reduced the need for tillage, and increase 

crop yields (Fernandez-Cornejo et al. 2014c). Due to their efficacy and affordability synthetic chemical 

herbicides remain the most commonly used among weed management tools and are expected to remain so 

for the foreseeable future. Sixty years ago, herbicides accounted for around 18% of pesticide use by 

volume on U.S. crops, and insecticides 58% percent. Today, herbicide and insecticide use account for 

approximately 76% and 6% percent of total pesticide applications, respectively (GROi 2018). In the 

United States, herbicides are currently used on 97% of U.S. corn acres (USDA-NASS 2019c).

In discussing herbicide use and herbicide resistant crops it is important to clarify that simply looking at

the total pounds of active ingredient (a.i.) used per year, pounds a.i. per acre used, and trends in increase 

or decrease in lbs a.i. per year—evaluation of these metrics in isolation of other factors—is not 

particularly useful for assessment of potential environmental or human health risks. Potential risks to the 

environment and human health—which are evaluated by the EPA for all herbicides (US-EPA 2020i) —

are relative to the specific herbicide a.i., its biological activity (mode of action), the potential toxicity of 

the a.i. to various taxa, its environmental mobility and persistence, degradation products, as well as the 

toxicity of herbicide formulations as there may be synergistic effects that derive from such formulations. 

Bearing these factors in mind, as weight and use rates are some of the most commonly reported metrics, 

and in response to comments received on EAs and EISs for HR crops requesting evaluation of pesticide 

use, provided below are usage data on glufosinate and other herbicides that may be used with DP23211

corn (Table 4-4).
4-11

Table 4-4. Herbicide Use in U.S. Corn Production – 2021

Herbicide a.i. lbs a.i./Yr

Application: lbs 

a.i./acre/Yr (Average)

Treated 

Acres, % of 

Area

Planted

Portion of Total 

Herbicide Use

(lbs)

ATRAZINE 59,180,000 0.844 65 24.88%

ACETOCHLOR 41,675,000 1.26 34 17.52%

GLYPHOSATE ISO. SALT 32,934,000 0.768 41 13.85%

S-METOLACHLOR 27,002,000 0.995 27 11.35%

GLYPHOSATE POT. SALT 26,812,000 0.992 25 11.27%

GLYPHOSATE 12,691,000 1.037 11 5.34%

METOLACHLOR 7,254,000 2.022 3 3.05%

MESOTRIONE 5,343,000 0.112 47 2.25%

2,4-D, 2-EHE 4,188,000 0.717 6 1.76%

DIMETHENAMID-P 2,891,000 0.566 6 1.22%

DICAMBA, DIGLY. SALT 2,394,000 0.316 8 1.01%

2,4-D, DIMETH. SALT 2,081,000 0.604 3 0.88%

GLYPHOSATE DIM. SALT 2,059,000 0.81 2 0.87%

PENDIMETHALIN 1,163,000 0.98 1 0.49%

DICAMBA, DIMET. SALT 1,096,000 0.223 5 0.46%

CLOPYRALID 1,055,000 0.074 15 0.44%

PARAQUAT 898,000 0.485 1 0.38%

GLUFOSINATE-AMMONIUM 849,000 0.429 2 0.36%

SIMAZINE 642,000 0.912 1 0.27%

TEMBOTRIONE 627,000 0.1 7 0.26%

DICAMBA, SODIUM SALT 446,000 0.103 5 0.19%

CLETHODIM 308,000 0.534 1 0.13%

BICYCLOPYRONE 278,000 0.032 9 0.12%

ISOXAFLUTOLE 251,000 0.071 4 0.11%

CLOPYRALID MONO SALT 214,000 0.074 3 0.09%

METRIBUZIN 208,000 0.172 1 0.09%

FLUMETSULAM 167,000 0.029 7 0.07%

DIFLUFENZOPYR-SODIUM 164,000 0.043 4 0.07%

PYROXASULFONE 120,000 0.081 2 0.05%

SAFLUFENACIL 107,000 0.059 2 0.04%

DICAMBA, POT. SALT 69,000 0.096 1 0.03%

THIENCARBAZONE-METHY 63,000 0.019 4 0.03%

TOPRAMEZONE 62,000 0.012 6 0.03%

DICAMBA 54,000 0.381 (Z) 0.02%

FLUROXYPYR 1-MHE 54,000 0.082 1 0.02%

FLUMIOXAZIN 31,000 0.065 1 0.01%

RIMSULFURON 17,000 0.017 1 0.01%

THIFENSULFURON 10,000 0.012 1 0.00%

HALOSULFURON-METHYL 4,000 0.011 (Z) 0.00%

FLUTHIACET-METHYL 2,000 0.003 1 0.00%

TOTAL 237,818,000
4-12

*Z = less than one whole percent. Herbicides in bold type are used with HR corn varieties. The data provide is 

largely based on USDA-NASS statistics for corn. Most of the annual NASS survey data generally captures 

around 80-90% of acreage for a given crop during a given year. Hence, the data presented likely provides a 

good approximation of herbicide use in corn production. Source: (USDA-NASS 2022a)

Glufosinate-Ammonium Use

Glufosinate is a non-selective, broad spectrum foliar-applied herbicide that is registered for pre-plant and 

post-emergence control of over 120 grass and broadleaf weeds on crop and non-crop sites. It is marketed 

in herbicide formulations such as Basta®, Finale®, Rely®, and Liberty®. Glufosinate is registered for 

use on both HR corn and conventionally bred varieties of canola, corn, cotton, and soybeans, as well as a 

variety of other conventionally bred crops, including apples, berries, citrus, currants, grapes, grass grown 

for seed, potatoes, rice, sugar beets, and tree nuts (US-EPA 2016e). Non-crop use sites include golf 

course turf, residential lawns, industrial and residential sites, utility and roadside rights-of-way, and 

timber site preparation for tree plantings. The crops which account for the most glufosinate use are 

soybean, cotton, and corn (together, over 75% of usage) (US-EPA 2016e); these crops have glufosinate 

resistant varieties. Currently, corn acres are treated with glufosinate at a rate of 0.4 lbs.a.i./acre (USDANASS 2020b), while almond acres are treated at a rate of 1.4 lbs. a.i./acre (US-EPA 2016e; USDA-NASS 

2020b). Several other crops, including apples, cherries, grapes (raisin, table, and wine), oranges, peaches, 

pears, pistachios, and walnuts are treated with glufosinate at rates greater than 1.0 lb a.i./acre (US-EPA 

2016e; USDA-NASS 2020b). An overview of glufosinate is in the United States is provided in Figure 

4-6. 
4-13

Figure 4-6. Glufosinate Use in the Conterminous United States – 2017 

Source: (USGS 2020b) 

Glufosinate-Resistant Corn 

While glyphosate resistant corn varieties have been the most widely grown, glufosinate and 2,4-D 

resistant corn varieties have also been available. Glufosinate resistant corn varieties were first deregulated 

in the mid-1990s (Table 4-5). 

Table 4-5. Glufosinate Resistant Corn, Soybean, and Cotton Crops

Crop Stacked-Trait herbicide tolerance traits Trade name Year commercialized in 

the United States

Corn Glyphosate and glufosinate SmartStax 2010

Corn Glyphosate and 2,4-D Enlist Duo 2014

Corn Glyphosate, glufosinate, 2,4-D and ACCase-FOP SmartStax Enlist 2018

Corn Glufosinate Liberty-Link 1996

Soybean Glyphosate and glufosinate Liberty-Link 2009

Soybean Glyphosate and dicamba Roundup Ready 

Xtend

2016

Soybean Glyphosate, glufosinate and 2,4-D Enlist E3 2019

Soybean Glufosinate LibertLink 2009

Cotton Glyphosate and dicamba Roundup Ready 

Xtend

2016

Cotton Glyphosate, glufosinate and 2,4-D Enlist 2016

Cotton Glyphosate and glufosinate GlyTol Liberty Link 2014

Source: (USDA-APHIS 2022a). 

After glufosinate resistant corn varieties were first deregulated (1996) there was a minor increase in 

glufosinate, up to around 2005. Glufosinate use in corn declined from 2005 to 2014, with a minor
4-14

increase of an average 0.002 lbs a.i./acre from 2014 to 2018. Overall, use of glufosinate on corn, even 

with glufosinate resistant corn varieties available, has been relatively limited. For corn, 234,000 lbs were 

applied in 2016, and 488,000 lbs were applied in 2018 (USDA-NASS 2020b). As of 2018, glufosinate use 

comprised 0.36% of total herbicides applied to corn (in lbs a.i.), and was used on only around 2% of corn 

acres (prior Table 4-4). 

Glufosinate Mode of Action and Phosphinothricin Acetyltransferase (PAT)

Bialaphos is a naturally occurring herbicidal compound produced by certain species of soil bacterium 

among the genus Streptomyces (Dayan et al. 2009; Dayan and Duke 2014). Bialaphos is a prototoxin, or 

protoxin, a non-toxic precursor of the phytotoxic compound L-phosphinothricin (referred to as 

phosphinothricin from here out). Bialaphos, once taken up by plant cells, is converted to 

phosphinothricin, which inhibits glutamine synthetase, an enzyme necessary for the production of 

glutamine (an essential amino acid) and ammonia detoxification. Reduced levels of glutamine and 

accumulation of ammonia in plant cells interferes with photosynthesis and other metabolic processes, 

resulting in plant death. Glufosinate is a synthetic form of phosphinothricin, and used as a non-selective 

broad spectrum herbicide. Glufosinate is the only commercial herbicide that targets glutamine synthetase.

Resistance to glufosinate is conferred by the enzyme phosphinothricin acetyltransferase (PAT), which 

inhibits the phytotoxic activity of glufosinate by acetylation, altering its chemical structure and function. 

Genes encoding PAT have been isolated from the bacterium Streptomyces hygroscopicus (e.g., the bar

gene, which is short for bialaphos resistance) (Thompson et al. 1987) and Streptomyces

viridochromogenes (pat gene) (Wohlleben et al. 1988). The pat gene, that introduced into DP23211 corn,

is very similar to the bar gene with 87 % nucleotide sequence identity. Both bar and pat encode PAT 

proteins with similar substrate affinity and biochemical activity (Wehrmann et al. 1996). 

Herbicide Resistant Weeds

Herbicide resistant (HR) weeds are more of an agronomic than ecological concern, however, HR weed 

populations can potentially contribute to environmental impacts when herbicide use or/and tillage is 

increased for their control. HR weeds relative to glufosinate use are discussed below. 

Herbicides are highly effective in the control of crop weeds, however, they impart selection pressure on

plants inherently resistant to the herbicide active ingredient (a.i.), or plants capable of developing 

resistance, resulting in survival of those particular plants. Inherently resistant plants occur naturally within 

weed populations. They differ slightly in genetic makeup from the rest of the population but remain 

reproductively compatible. HR plants are normally present in a weed population in extremely small 

numbers; about 1 in 100,000 to less than 1 in 1,000,000 (Campbell et al. 2015). The repeated use of one 

herbicide—a single mode of action (MOA)—allows these few resistant plants to survive and reproduce; 

thereby selecting for the naturally resistant weeds.

10 The number of resistant plants then increases in the 

population. 

Weed populations can also “evolve” resistance to an herbicide a.i., where the weed adapts to an external 

chemical stressor. Evolved resistance is broadly classified into two types; target-site resistance (TSR) and 

10 The MOA is the unique biological mechanism at the cellular/molecular level by which an herbicide is lethal to a 

plant.
4-15

non-target-site resistance (NTSR). TSR mechanisms involve mutation(s) in the target site of action of an 

herbicide, resulting, for instance, in an insensitive or less sensitive target protein (Jugulam and Shyam 

2019). A mutation in a gene can cause a minor change in a protein’s structure resulting in an herbicide no 

longer being able bind and alter the protein’s function, rendering the plant “resistant” to the herbicide 

(e.g., (Yang et al. 2016; Rey-Caballero et al. 2017)). Additionally, TSR can also evolve as a result of the 

over-expression of the target gene (Jugulam and Shyam 2019). 

NTSR to herbicides in weeds can be conferred as a result of the alteration of one or more physiological 

processes, such as impeded herbicide absorption or translocation, sequestration of the herbicidal 

compound, and/or increased metabolism/breakdown of the herbicide. The mechanisms of NTSR are 

generally more complex to decipher than TSR. Development of NTSR can also impart cross-resistance to 

herbicides with different modes of action, and complicate resistance management strategies (Jugulam and 

Shyam 2019).

Over-reliance on herbicides for weed control in lieu of non-chemical methods, and continued issues with 

the development of HR weed populations, has generated considerable attention on how to best utilize

herbicides so as to sustain their longevity and prevent the development of HR weed populations (e.g., 

(Duke 2015; Owen 2016; Heap and Duke 2018; Beckie et al. 2019; Korres et al. 2019), and others). 

Currently, 48 states report the presence of HR weed populations (Heap 2020). This is not a recent 

concern, nor is it unique to HR crops. Herbicide resistant weed populations have been occurring since the 

advent of chemical herbicides in the 1950s. As illustrated in Figure 4-7, significant increases in HR weed 

populations began to occur in the mid-1980s. Currently, there are approximately 165 unique cases of HR 

weeds in the United States (weed species by herbicide mode of action (MOA)) (Heap 2020). 
4-16

Figure 4-7. HR Weeds in the United States, 1950 – 2020

Source: (Heap 2020) 

Globally, weeds have developed resistance to 23 of the 26 herbicide MOAs that are currently available, 

which reduces the number of herbicide options available to growers (Figure 4-8). Most corn growing 

states have from around 3 to 8 different species of weeds that are herbicide resistant (Heap 2020). There 

have been no herbicides with completely novel MOAs developed and commercialized over the last 

several decades. Consequently, there are no herbicides with new MOAs with which to control HR weeds. 

 

Figure 4-8. Increase in the Development of Herbicide Resistance: Herbicide Modes of Action

The herbicide groups with the most HR weeds are acetolactate synthase (ALS) inhibitors (i.e., imidazolinone and 

imazethapyr); ACCase inhibitors (i.e., phenylpyrazoline); triazine based photosynthesis II inhibitors (i.e., atrazine); 

synthetic auxins (i.e, dicamaba, 2,4-D); bipyridilium based photosynthesis I inhibitors such as paraquat; glycines, 

which include the EPSP synthase inhibitor glyphosate; various ureas and amides that inhibit the photosynthesis II 

process; and dinitroaniline based microtubule inhibitors such as trifluralin. Source: (Heap 2020) 

Problematic is that fact that many HR weed populations continue to develop resistance to more than one 

herbicide MOA. For example, in U.S. corn crops (as of the end of 2020), there were 16 instances with a 

weed population developing resistance to 2 MOAs, 5 confirmed weed populations with resistance to 3 

MOAs, 3 with confirmed resistance to 4 MOAs, and 1 species (tall waterhemp) with confirmed resistance 

to 5 herbicide MOAs (Heap 2020). Relative to DP23211 corn: To date there are only two weed species 

reported to be resistant to glufosinate-ammonium in the United States; Italian ryegrass (Lolium perenne

ssp. multiflorum), with populations reported in orchards in California and Oregon, and Palmer Amaranth

(Amaranthus palmeri), with a population reported in Arkansas’ Mississippi County, this being discovered 

in 2020 (Heap 2020; AgWeb 2021). 

0

25

50

75

100

125

150

175

1957197219751977197919811983198519871989199119931995199719992001200320052007200920112013201520172019

No. of Resistant Weed Biotypes Reported

Herbicide Resistant Weeds by Year and Mode of Action 

ACCase inhibitors ALS inhibitors

Photosystem II inhibitors PSII inhibitor (Ureas and amides)

PSI Electron Diverter EPSP synthase inhibitors

Microtubule inhibitors Synthetic Auxins

HPPD inhibitors Other
4-17

Herbicide Resistant Weed Management 

Strategies for managing weeds and avoiding the development of HR weed populations in U.S. agriculture 

are steadily being refined (e.g., (Duke 2015; Owen 2016; Heap and Duke 2018; Beckie et al. 2019; 

Korres et al. 2019), and others). A combination of preventive, cultural, mechanical, biological, and 

chemical methods are required for effective weed, and weed resistance management. The coordinated use 

of these is termed integrated weed management (IWM). Crop producers are advised to, and are 

implementing, IWM strategies to address development of HR weeds—strategies developed by the crop 

protection and seed industries, the USDA, university extension services, the EPA, and Weed Science 

Society of America (WSSA). In 2017, the EPA issued PR Notice 2017-2, Guidance for HerbicideResistance Management, Labeling, Education, Training and Stewardship (US-EPA 2017a), which 

provides registrants and growers detailed information on slowing the development and spread of HR 

weeds. The EPA focused on and provided the guidance for herbicide use because: (1) herbicides are the 

most widely used agricultural chemicals, (2) no new herbicide mechanisms MOAs have been developed 

in the last 30 years, (3) the number of HR weeds has rapidly increased over the last 30 years, and (4) the 

potential economic impact of HR weeds on U.S. crop production are significant (US-EPA 2017a). 

4.3.1.2.2.4 Insect and Insect Resistance Management

Corn and other crop plants modified to express insecticidal Bt based Cry toxins can provide effective pest 

control as well as economic gains for farmers (James 2014; Brookes and Barfoot 2018b). Reductions in 

insecticide use with insect resistant (IR) crops has also resulted in environmental and worker health

benefits (James 2014; Brookes and Barfoot 2018b). Due to the benefits provided by Bt crops there have

been significant levels of adoption; Bt corn currently comprises around 80% of U.S. corn crops, and Bt 

cotton 89% (USDA-ERS 2022b).

Studies conducted by USDA-ERS (Fernandez-Cornejo et al. 2014a; Fernandez-Cornejo et al. 2014b), the 

National Academy of Sciences (NAS 2016), and others (Osteen and Fernandez-Cornejo 2016; Fleming et 

al. 2018) have found that soil-applied and foliar insecticide use—in terms of lbs a.i./acre—has declined in 

corn production due in part to the adoption of Bt corn (Figure 4-9). For example, insecticide use among 

U.S. corn farmers fell by over 80% from 1996 to 2018 (Fernandez-Cornejo et al. 2014c; USDA-NASS 

2020b). A combination of use of integrated pest management (IPM) strategies, the success of the boll 

weevil eradication program, and introduction of Bt crops led to a significant reduction in the number of 

insecticide applications. Insecticide use with corn, which peaked in the late 1970s and 1980s at an average 

0.35 – 0.45 pounds per acre, declined throughout the 1990s and 2000s to an average of under 0.03 pounds 

per planted acre in 2018 (latest data). As of 2018, 80% of U.S. corn acres were planted with IR varieties, 

only 13% of corn acres were treated with insecticides (USDA-NASS 2019c; USDA-ERS 2022a). 

Insecticide use on corn and cotton are at near all-time lows, averaging around 0.02 – 0.03 lbs a.i./acre, and 

0.29 – 0.35 lbs a.i./acre, respectively (USDA-NASS 2020b). Soil and foliar applied insecticides currently 

use in U.S. corn production are provided in Table 4-6.
4-18

Figure 4-9. Insecticide Use in Bt Corn Production

Source: (Fernandez-Cornejo et al. 2014c; USDA-NASS 2020b) 

Table 4-6. Soil and Foliar Applied Insecticide Use in Corn – 2018

Insecticide Active Ingredient Class

Pounds 

a.i./yr

Application: 

lbs 

a.i./acre/Yr 

(Average)

Treated 

Acres, % 

of Area 

Planted

Portion of 

Total 

Insecticide 

Use

Bifenthrin pyrethroid 402,000 0.089 5 19.3%

Chlorantraniliprole ryanoid 6,000 0.062 < 1 0.3%

Chlorpyrifos organophosphate 623,000 0.818 1 29.9%

Cyfluthrin pyrethroid 10,000 0.015 1 0.5%

Lambda-cyhalothrin pyrethroid 59,000 0.026 3 2.8%

Permethrin pyrethroid 31,000 0.06 1 1.5%

Propargite organosulfur 587,000 2.031 < 1 28.1%

Spiromesifen butenolide 11,000 0.153 < 1 0.5%

Tebupirimphos organothiophosphate 45,000 0.109 < 1 2.2%

Tefluthrin pyrethroid 158,000 0.1 2 7.6%

Terbufos organophosphate 7,000 0.073 < 1 0.3%

Zeta-Cypermethrin pyrethroid 17,000 0.017 1 0.8%

TOTAL 2,087,000 13%

* Does not include seed treatments

Source: (USDA-NASS 2020b) 

In areas where cultivation of Bt corn and Bt cotton is high, the use of Bt crop varieties has also been 

associated with reduced insecticide use in adjacent cropping systems cultivating non-Bt varieties, a result 

of the area-wide suppression of insect pest populations (NAS 2016). For example, several studies have 

found that the use of Bt corn and Bt cotton are positively associated with the area-wide suppression of

European corn borer and pink bollworm, respectively (e.g., see review by Dively et al. (2018)). In 

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0

10

20

30

40

50

60

70

80

90

100

19601962196419661968197019721974197619781980198219841986198819901992199419961998200020022004200620082010201220142016

Average lbs a.i. / acre

TTL Corn Acres and % Bt Corn Acres

Insecticide Use: Bt Corn, 1960 - 2018

TTL Corn Acres Bt Corn % Acres lbs a.i. /acre
4-19

general, peer review literature and similar studies indicate that cultivation of Bt crops can potentially 

provide tangential benefits to adjacent farms by tempering the prevalence of certain insect pest 

populations, reducing the need for insecticide use in nearby cropping systems (NAS 2016)). 

While IR crops can provide agronomic and economic benefits, they can also create selection pressure on

insect populations inherently resistant to transgenic Bt trait proteins (discussed further below). 

Insect Resistant Management With Insect Resistant Crops

Similar to HR weeds, continued exposure of insects to insecticides can result in the development of 

resistance in populations. The first documented case of insect resistance to an insecticide was in 1914, 

which described the resistance of the San Jose scale (Quadraspidiotus perniciosus) to lime-sulfur 

(Melander 1914). In 1916, resistance to hydrogen cyanide fumigant was identified in a citrus pest, the 

California red scale (Aonidiella auruntii (Maskell)), and in the black scale (Saissetia oleae (Olivier)) 

(Melander 1914; Quayle 1922). With the steady introduction and use of synthetic chemical insecticides in 

insect control programs, the number of documented cases of insecticide resistance, worldwide, had

increased to 600 species by 2017 (Mota-Sanchez and Wise 2017). 

The risk of resistance development is, as with synthetic chemical insecticides, an important issue for crop 

plants engineered to express insecticidal proteins—plant incorporated protectants (PIPs) (Fleming et al. 

2018).11 While there are agronomic, environmental, and economic benefits in the use of IR cropping 

systems, the potential for the development of insect populations resistant to PIPs is present and has 

occurred in some areas. For example, resistance of corn earworm (Helicoverpa zea) to Cry1Ab, Cry1Ac, 

and Cry1A.105+ Cry2Ab has emerged in the eastern and central Cotton Belt (Luttrell et al. 2004; Ali et 

al. 2006; Tabashnik et al. 2008; Bruce and Yves 2010; Dively et al. 2016). Evolved resistance of CRW to 

Cry3Bb1 corn, mCry3A corn, and eCry3.1Ab corn has also been documented, in multiple midwestern 

states (Gassmann et al. 2016; Jakka et al. 2016). Additionally, cross-resistance among Cry3Bb1, mCry3A, 

and eCry3.1Ab has been reported (Jakka et al. 2016). 

While insects are capable of developing resistance to chemical based insecticides, for PIP based crops

there can be other considerations: 

• insecticidal proteins may be expressed at high levels in plant tissues;

• the proteins are produced by the plant continually during the growing season (i.e., throughout the 

lifespan of the plant); and

• some of the major target pests, such as European corn borer, corn rootworm, and pink bollworm, 

feed almost exclusively on corn or cotton. 

These factors can increase insect exposure to an insecticidal protein and thereby increase selection 

pressure for development of resistant populations. The cases of pest resistance to Bt Cry proteins 

11 It should be noted, development of resistance is likewise possible with use of Bt sprays, one of the most widely 

used foliar applied insecticides used in conventional and organic crops (Tabashnik BE, Brevault T, and Carriere Y. 

2013. Insect resistance to Bt crops: lessons from the first billion acres. Nat Biotech,Vol. 31(6), pp. 510-521. 

Retrieved from https://www.nature.com/articles/nbt.2597.pdf .) 
4-20

produced by transgenic crops increased from 3 in 2005 to 16 in 2016 (Tabashnik and Carrière 2017). 

These 16 cases represent resistance of some populations of seven major pests in five countries to each of 

the nine Cry toxins produced by widely grown Bt crops: Cry1Ab, Cry1Ac, Cry1A.105, Cry1Fa, Cry2Ab, 

Cry3Bb, mCry3A, eCry3.1Ab, and Cry34/35Ab. Both corn earworm (Jakka et al. 2016) and CRW

(Gassmann et al. 2016; Jakka et al. 2016) have developed resistance to multiple Cry toxins (e.g., 

Cry3Bb1, mCry3A, and eCry3.1Ab). For the 16 cases of resistance that have been documented, the 

average time for evolution of resistance was around 5.2 years (Tabashnik and Carrière 2017). 

The use of Bt based crops has been effective in the control of crop pests, although the efficacy wanes

when a pest population adapts to the mechanism of action of the particular introduced PIP, and becomes 

less susceptible. Thus, when not judiciously utilized, the PIPs in IR crops decline in efficacy over time, 

while also contributing to increasingly limited pest management options for IR, conventional, and organic 

cropping systems. For instance, Bt based insecticides (Cry toxins) are widely used in organic farming, 

either as a spray or ground application to help control insect pests, and one of the few insecticides

permitted by USDA organic standards. 

Effective insect resistance management (IRM) is a basic aspect of IR cropping systems (Tabashnik and 

Carrière 2017). Several strategies, such as the use of multiple Cry proteins (PIPs) in transgenic crops, 

spatial and temporal refuges, and high or ultrahigh doses of Cry protein are employed to prevent the 

development of insect resistance. The IRM strategy that has received the most attention involves a “high 

dose/refuge” (HDR) concept (Bates et al. 2005; Siegfried and Hellmich 2012). With this approach, insects 

that feed on Bt crops are exposed to a high dose of toxin. This is complemented with a refuge, a non-Bt 

crop variety or other plant hosts, which supports a population of unexposed insects, thereby eliminating 

selection pressure on those insect populations. Resistant insect pest populations that develop as a result of 

exposure to Cry toxins, instead of mating with each other, are able to mate with individuals among a large 

number of non-resistant pests from the refuge. This process essentially dilutes resistance genes in 

populations and sustains populations of susceptible insects (Bates et al. 2005; Siegfried and Hellmich 

2012).

Other strategies include the use of combinations of different Cry proteins, proteins that have different cell 

surface receptors or different mechanisms of action (Reisig and Kurtz 2018), use of RNAi based PIPs (Ni 

et al. 2017; Vélez et al. 2020), and use of insecticidal non-Bt based proteins (Boeckman et al. 2019).

DP23211 corn utilizes the latter two, RNAi and a non-Bt toxin. 

To help counter the development of insect resistance the EPA has mandated the implementation of an 

IRM plan for each commercially registered Bt derived PIP (US-EPA 2020j). The goal of an IRM plan is 

to prevent or delay the development of resistant insect populations. In 2017, the EPA issued PRN 2017-

1, Guidance for Pesticide Registrants on Pesticide Resistance Management Labeling (US-EPA 2017b)

for all conventional pesticides and resistance management. The EPA also requires that any incidents of 

pest resistance for a regulated pesticide product be reported to the EPA. This reporting requirement is in 

accordance with the FIFRA Adverse Effects Reporting Section 6(a)(2), which requires pesticide product 

registrants to submit adverse-effects information about their products.

In 2018, the USDA announced updated guidance to the National Road Map for Integrated Pest 

Management (USDA 2018). The update is the product of the Federal Integrated Pest Management 
4-21

Coordinating Committee (FIPMCC), a joint effort that is coordinated by the Office of Pest Management 

Policy in the Office of USDA’s Chief Economist with representatives of all federal agencies with 

responsibilities in IPM research, implementation, or education programs. These agencies include 

Environmental Protection Agency (EPA), Department of the Interior (DOI), and Department of Defense 

(DoD).

4.3.1.3 Potential Effects on U.S. Corn Production

Potential Effects on Land Use

Approval of the petition and subsequent production of DP23211 corn would have little to no effect on 

lands used for U.S. corn production. U.S. corn acreage is primarily determined by market demand for 

corn-based food, feed, fuel, and industrial commodities, independent of APHIS’ regulatory status 

decision. Acreage could also be determined by the yields/acre achieved over time with given corn 

varieties, which in turn is determined by the inherent potential yield of a given corn cultivar, pest and 

weed pressures present, the potential contribution of HR and IR traits to effectively controlling weeds and 

insect pests (which also contributes to yield), weather, and agronomic production factors. DP23211 corn 

exhibited slightly lower yield per acre than the control corn in field trials, although is within the normal 

range for dent corn varieties (Pioneer 2020). DP23211 corn, if adopted by growers, would be expected to 

replace other HR/IR field corn varieties currently cultivated, as opposed to augmenting current corn 

crops. 

Agronomic Practices and Inputs 

Pioneer conducted agronomic and ecological evaluations to assess the comparability of DP23211 corn to 

conventional corn (Pioneer 2020). Agronomic characteristics evaluated included factors that influence 

reproduction, growth, and crop survival. In each field trial DP23211 corn was comparable to the 

conventionally bred, near-isoline control corn or conventional comparators, with the exception of the days 

to flowering and final population metrics. The mean values for days to flowering and final population are, 

however, within the reference range for Zea mays varieties (Anderson et al. 2020). Ecological evaluations 

included responses to biotic and abiotic stressors during multi-year and multi-site field trials. 

Observations included the presence of insect and disease stressors in the field and DP23211 corn 

responses. In each field trial DP23211 corn performed similarly to the conventionally bred, near-isoline 

control corn plants.

These studies demonstrated that the agronomic practices and inputs used for DP23211 corn would be

similar to those of other corn varieties, except for, as an HR variety, facilitating the use of glufosinate, and 

as an IR variety, less reliance on use of synthetic chemical insecticides for insect pest control. As an IR 

corn variety comprised of plant incorporated protectants (PIPs) with specify for WCR, cultivation of 

DP23211 corn would likely entail less use of soil- and foliar-applied insecticides to control WCR.

As summarized in Table 4-4, glufosinate is one of around 48 herbicides used in corn production, 

comprising 0.23% of total herbicide use on corn in 2018. Of 19 HR corn varieties APHIS has previously 

deregulated, 11 are glufosinate resistant (USDA-APHIS 2022a). There are several glufosinate resistant 

corn products currently available to growers (e.g., LibertyLink®, GenuityTM SmartStaxTM). DP23211 corn 

would present growers another option among currently available HR/IR varieties. Corn growers will
4-22

select a particular HR/IR variety based on insect and weed populations present; resistant insect and weed 

populations; the potential for high yield; efficacy of the PIP and herbicide(s) used with the crop; costs of 

pesticide inputs; and ease and flexibility in management of insect pests and weeds. At the national level, 

HR/IR corn varieties have emerged as the most favored by growers, currently comprising around 80% of 

U.S. corn acres (Figure 4-10). Note that adoption rates will vary at the state level on an annual basis due 

to weed and pest pressures, among other factors. 

Figure 4-10. Share of Corn Acreage Planted with Stacked-Trait HR/IR Seed – 2022

Source: (USDA-ERS 2022b)

In the event DP23211 corn is available for use growers would have the option to (1) produce DP23211 

corn in lieu of other glufosinate resistant varieties they are currently cultivating, or (2) produce DP23211 

corn in lieu of HR varieties that are resistant to herbicides other than glufosinate. To the extent growers 

do the latter, an increase in glufosinate use and decrease/substitution in use of other herbicides with 

similar spectrums of weed control would occur in corn production. Thus, DP23211 corn production, to 

the extent grown, would influence the mix of herbicides used on U.S. corn acres. No significant increase 

in total herbicide use on corn would be expected in either case (e.g., Table 4-4). Annual fluctuations in 

total herbicide use are expected due to variances in the use rates in lbs a.i./acre/year among herbicides, 

herbicide rotation, weed and HR weed pressures, and annual acreage planted to corn. 

Weed and HR Weed Management

The development of HR weeds continues in many areas of the United States and is problematic for 

growers (Heap 2020). Most corn growing states have from 3 to 8 different species of weeds that are 

herbicide resistant (e.g., Iowa has 8, with tall waterhemp and giant ragweed particularly problematic

(Heap 2020)). Glufosinate is considered a valuable herbicide for grower's in the management of weeds, 

and weed resistance (US-EPA 2016e; Takano and Dayan 2020). This is attributed to its MOA (a 

glutamine synthetase inhibitor), and the fact that there are only two reported weed species in the United 

States that have developed resistance; Italian ryegrass (Lolium perenne ssp. multiflorum), with 

0

10

20

30

40

50

60

70

80

90

Percent Adoption

Adoption of Herbicide and Insect Resistant Corn Varieties 

in the United States 

IR Corn HR Corn HR/IR Corn
4-23

populations in orchards in California and Oregon, and Palmer amaranth (Amaranthus palmeri), with a

population in Arkansas’ Mississippi County reported in 2020 (Heap 2020; AgWeb 2021). 

Certain herbicide MOAs are more susceptible to development of resistance. For example, development of 

resistance to ALS-inhibitors is the most common. As of the end of 2020, 166 cases of weeds resistance to 

ALS-inhibitors had been reported worldwide (Heap 2020), a trend that is attributed in part to the relative 

ease with which plants can evolve resistance to its MOA. Several single amino acid substitutions that are 

sufficient to confer resistance to ALS-inhibitors have been identified in genes (Holt et al. 2013). In 

contrast, development of resistance to the PSII-inhibitor herbicide group is considered more difficult (29 

reported cases worldwide) because in most cases reported resistance results from a specific base pair 

substitution in the psbA gene—from adenine in the susceptible to guanine in the resistant biotype—which 

is maternally inherited (Hirschber et al. 1984; Holt et al. 2013). Currently, there are only five reported 

weed species, worldwide, developing resistance to glufosinate—glutamine synthetase inhibition (Heap 

2020; AgWeb 2021). While development of glufosinate resistance in weedy plants has occurred, it 

appears the target and non-target pathways by which plants can evolve resistance to glutamine synthetase 

inhibition are comparatively limited, relative to other herbicide MOAs (Takano and Dayan 2020). 

Preventing the development of glufosinate resistance weed populations—sustaining the efficacy of the 

herbicide MOA—would be relative to implementation of EPA resistance management guidance (US-EPA 

2017a), Pioneer product stewardship requirements (Pioneer 2019), and use of recommended IWM 

strategies in DP23211 corn cropping systems (e.g., (Heap and Duke 2018; Beckie et al. 2019; Gage et al. 

2019)). Corteva Agriscience, the parent company of Pioneer, is a member of the global Herbicide 

Resistance Action Committee (HRAC 2020), an industry-based group administrated by CropLife 

International (CLI 2020). HRAC supports and equips regional offices to help educate farmers, 

agronomists, and industry members in the management of herbicide-resistant weeds. In 2017 the EPA 

issued PR Notice 2017-2, Guidance for Herbicide-Resistance Management, Labeling, Education, 

Training and Stewardship (US-EPA 2017a), which provides registrants and growers information on 

slowing the development and spread of HR weeds. In addition, the EPA has issued specific guidance for 

glufosinate resistance management (US-EPA 2016b). 

Insect Pest Management

Insects are highly adaptable and, over time, can evolve resistance to any single control method; synthetic 

chemicals, Bt toxins, or RNAi based mechanisms (Mallet 1989; Tabashnik and Carrière 2017). Western 

corn rootworm (Diabrotica virgifera virgifera LeConte) is a major pest of corn in the United States and

has adapted over time to many management tactics (Gray et al. 2009; Miller et al. 2009). Broadcast 

application of organochlorine insecticides starting in the late 1940’s became rapidly ineffective with 

WCR control issues apparent by late 1950’s (Ball and Weekman 1962). Aerial applications of carbamates 

and organophosphates selected for adult WCR resistance in the 1990’s (Melander 1914). Resistance to 

transgenic corn producing rootworm-specific Cry toxins was initially reported for Cry3Bb1 in 2009, 

mCry3a in 2011, and Cry34/35Ab1 in 2016 (Gassmann et al. 2016; Jakka et al. 2016). The practice of 

corn rotation with a nonhost crop was circumvented in areas of the eastern Corn Belt by WCR oviposition 

in nonhost crops, indicating the evolution of behavioral resistance (Levine et al. 2002; Gray et al. 2009; 

Meinke et al. 2009). These events collectively have made WCR management in U.S. cropping systems

very difficult (Souza et al. 2019).
4-24

A basic element of insect resistance management (IRM) is the implementation of several different types 

of control measures (Karlsson Green et al. 2020). RNAi is utilized as an alternative, or complement, to Bt 

toxins in IR crops to help diversify control methods (MOAs), and thereby reduce selection pressure for 

resistance in insect populations (Kim et al. 2015; Head et al. 2017; Ni et al. 2017). Similarly, the 

IPD072Aa protein provides a MOA that differs from Cry toxins. Because the MOAs so markedly differ 

between Bt toxins (cell surface receptor recognition and binding) and RNAi (targeted mRNA cleavage 

and disruption of mRNA translation), development of cross-resistance is unlikely. Development of dualresistance to both a Bt based toxin and RNAi is conceptually possible (Vogel et al. 2019), although the 

topic has not been well studied (i.e., controlled lab and field studies). In general, development of dualresistance to a Cry toxin and RNAi mechanism would be considered an unlikely event. Based on current 

data, development of cross-resistance to Bt toxins and the IPD072Aa protein would not be expected

(Schellenberger et al. 2016; Boeckman et al. 2019).

Current data indicate that RNAi can be highly species-specific if the dsRNA construct is well-designed

(Agrawal et al. 2003; Vogel et al. 2019; Christiaens et al. 2020). The DvSSJ1 dsRNA expressed in 

DP23211 corn has been shown to primarily affect Diabrotica species within the Chrysomelidae family of 

Coleoptera—namely WCR and southern corn rootworm (SCR) (Hu et al. 2019). WCR is the most 

sensitive species, based on 14 day feeding bioassays, with a median LC50 of 0.036 ng/mg diet (parts per 

million (ppm)) (Table 4-7). Of the other Coleoptera and Lepidoptera species evaluated, SCR was 

observed to be the only species affected, with decreased survival at a dietary concentration of 100 ng/ml

(ppm)—much less sensitive/susceptible than WCR. The remaining coleopteran and lepidopteran species 

evaluated were unaffected at diets containing 1 ng/mg DvSSJ1 dsRNA, and unlikely to be affected 

feeding on DP23211 corn under field conditions (Boeckman et al. 2019). For example, expression of 

DvSSJ1 dsRNA is around 0.001 to 0.007 ng/mg in grain, 0.002 to 0.038 ng/mg in leaf, and 0.0002 - 0.009 

ng/mg in root (Table 4-8). 

Note that because expression of DvSSJ1 dsRNA in DP23211 corn is low, it was necessary to produce 

RNA microbially using in vitro techniques in order to obtain enough DvSSJ1 dsRNA to perform 

specificity analyses. Sequence analyses confirmed that the microbially produce dsRNA was equivalent to 

the dsRNA produced in planta, and suitable for use in specificity studies (Pioneer 2020). 

 Table 4-7. Effects of DvSSJ1 dsRNA on Coleoptera and Lepidoptera Species 

Order Family Species Common Name Endpointsa LC50 or NOEC

Coleoptera Chrysomelidae Diabrotica virgifera

vergifera

Western Corn

Rootworm 

S, W LC50 = 0.036 

ng/mg

Chrysomelidae Diabrotica 

undecimpunctata

Southern Corn 

Rootworm 

S, W 100 ng/ml

Chrysomelidae Leptinotarsa

decemlineata

Colorado

Potato Beetle

S, W >1.0 ng/mgb

Tenebrionidae Tenebrio molitor Mealworm S, W >1.0 ng/mg

Tenebrionidae Zophobas morio Superworm S, W >1.0 ng/mg

Tenebrionidae Tribolium castaneum Red Flour Beetle S, W >1.0 ng/mg

Coccinellidae Epilachna varivestis Mexican Bean

Beetle

S, W >1.0 ng/mg
4-25

Coccinellidae Hippodamia convergens Convergent

Lady Beetle

S, W, AE >1.0 ng/mg

Coccinellidae Coleomegilla maculata Pink Spotted Lady 

Beetle

S, W, AE >1.0 ng/mg

Staphylinidae Dalotia coriaria Rove Beetle S >1.0 ng/mg

Lepidoptera Crambidae Ostrinia nubilalis European Corn

Borer

S, W >1.0 ng/mg

Noctuidae Helicoverpa zea Corn Ear Worm S, W >1.0 ng/mg

Nymphalidae Vanessa cardui Painted Lady S, W >1.0 ng/mg

Tortricidae Cydia pomonella Codling Moth S, W >1.0 ng/mg

a. S = Survival; W = Weight; AE = Adult Emergence 

b. For all species studied except for western corn rootworm and southern corn rootworm, there were no 

adverse effect observed (NOEC) at 1ng DvSSJ1_210 dsRNA per mg diet

Source: (Pioneer 2020) 

 Table 4-8. DvSSJ1 dsRNA Tissue Expression Levels in DP23211 Corn 

 ng/mg Tissue Fresh Weight

(parts per million)

Root 0.00019 - 0.00877

Leaf 0.00177 - 0.0379

Grain 0.00102 - 0.0073

Pollen 0.000330 – 0.00096

Boeckman et al. (2019) evaluated the spectrum of activity of IPD072Aa in diet bioassays. The IPD072Aa

protein used in these assays was microbially produced, versus in planta, although the activity of 

microbially produced and in planta IPD072Aa is considered equivalent (Pioneer 2020). IPD072Aa was 

fed at high concentrations in sub-chronic and chronic feeding studies to 11 different Coleoptera species 

representing four families, and an additional four species representing four families of Lepidoptera (Table 

4-9). No adverse effects were noted in the Lepidoptera species. A range of responses was observed within 

each of the four families of Coleoptera evaluated, which included either no-observed effects, or reduced 

growth, developmental delays, and/or reduced survival. The range of expression levels of IPD072Aa

protein in DP23211 corn tissue, over the course the DP23211 corn life cycle, are provided in 

Table 4-10. 

Table 4-9. IPD072Aa Protein Spectrum of Activity Bioassay Evaluation

Order Family Species Common Name Endpointsa LC50, Effects Concentration, 

or NOEC

Coleoptera Chrysomelidae Diabrotica virgifera

vergifera

Western Corn 

Rootworm

S LC50 = 26 ng/mg diet

Coleoptera Chrysomelidae Diabrotica

undecimpunctata

Southern Corn

Rootworm

S*

W* 

1000 ng/mg diet

100 ng/mg diet

Coleoptera Chrysomelidae Leptinotarsa

decemlineata

Colorado Potato

Beetle

S 

W 

1000 ng/mg diet

1000 ng/mg diet 
4-26

Coleoptera Tenebrionidae Tenebrio molitor Mealworm S*

W* 

1000 ng/mg diet

500 ng/mg diet

Coleoptera Tenebrionidae Zophobas morio Superworm S 

W* 

1000 ng/mg dietb

100 ng/mg diet

Coleoptera Tenebrionidae Tribolium

castaneum

Red Flour Beetle S, W No adverse effectc

Coleoptera Coccinellidae Epilachna

varivestis

Mexican Bean 

Beetle

S*

W* 

500 ng/mg diet

100 ng/mg diet

Coleoptera Coccinellidae Hippodamia

convergens

Convergent Lady

Beetle

S*

W* 

AE* 

1000 ng/mg diet

100 ng/mg diet

500 ng/mg diet

Coleoptera Coccinellidae Coleomegilla

maculata

Pink Spotted Lady

Beetle

S*

W* 

AE*

500 ng/mg diet

500 ng/mg diet

500 ng/mg diet

Coleoptera Coccinellidae Cryptolaemus

montrouzieri

Mealybug 

Destroyer

S 

W 

No adverse effectc

100 ng/mg dietd

Coleoptera Staphylinidae Dalotia coriaria Rove Beetle S No adverse effectc

Lepidoptera Crambidae Ostrinia nubilalis European Corn 

Borer

S, W No adverse effectc

Lepidoptera Noctuidae Helicoverpa zea Corn Ear Worm S, W No adverse effectc

Lepidoptera Nymphalidae Vanessa cardui Painted Lady S, W No adverse effectc

Lepidoptera Tortricidae Cydia pomonella Codling Moth S, W No adverse effectc

a. S = Survival, W = Weight, AE = Adult Emergence. Those with an asterisk (*) were statistically significant at the 

concentrations reported

b. 20% mortality was reported at 1000 ng/mg diet, although not statistically significant relative to the control

c. No adverse effects on survival or weight at 1000ng/mg diet

d. Weight gain was statistically lower for MBD in the 100 ng/mg concentration (P = 0.025); however, no effects were 

observed at 500 (P = 0.167) and 1,000 ng/mg (P = 0.468) IPD072Aa

Source: (Boeckman et al. 2019; Pioneer 2020) 

 Table 4-10. IPD072Aa Tissue Expression Levels in DP23211 Corn

 ng/mg Tissue Dry Weight

 (parts per million)

Root 0.93 - 84

Leaf 0.054 - 39

Grain 0.51 – 4.8

Pollen 0.14 – 1.3

The bioassay data indicate that IPD072Aa protein was shown to primarily affect WCR. This is due to 

binding specificity for mid-gut epithelial cell surface receptors in western corn rootworm—specifically 

for the brush border membrane of enterocytes—although the exact mechanism of binding has not yet 

been clearly elucidated (Pioneer 2020). Once in the midgut, the IPD072Aa protein dimer disassociates 

into a monomeric form which binds to receptors on the brush border membrane. After binding, disruption 

of gut function caused by death of enterocytes leads to WCR death. Lethal concentrations ranged from 12 

to 39 ng/mg IPD072Aa, with a mean of 26 ng/mg (Boeckman et al. 2019). 
4-27

The closely related southern corn rootworm also exhibited sensitivity to IPD072Aa, although at a much 

higher dose, where 17% of treated insects exhibited mortality at 500 ng/mg IPD072Aa. Reductions in 

weight were observed and statistically significant at dietary concentrations of 100 ng/mg and higher. No 

effects were observed on the survival or growth of Colorado potato beetle (Leptinotarsa) at

concentrations up to 1,000 ng/mg.

Within Tenebrionidae, survival of super worm (Zophobas morio) was unaffected when fed 1,000 ng/mg 

IPD072Aa; however, mean weight was lower at concentrations 100 ng/mg and higher (Boeckman et al. 

2019). Survival of yellow mealworm (Tenebrio molitor) was affected at 1,000 ng/mg, and weight affected 

at 500 ng/mg IPD072Aa. IPD072Aa had no effects on red flour beetle (Tribolium castaneum) at the

concentrations tested.

Species within the Coccinellidae showed varying levels of sensitivity to IPD072Aa. Mexican bean beetle

(Epilachna varivestis) was the most sensitive Coccinellidae insect tested—statistically significant effects 

on survival at 500 ng/mg IPD072Aa were observed. Reduced growth was observed in Mexican bean 

beetle fed 100 ng/mg IPD072Aa. The Mexican bean beetle is one of the few North American lady beetles 

that feed on plants rather than other insects and can be a significant agricultural pest in legume crops. 

Pink spotted lady beetles (Coleomegilla maculata De Geer) and convergent lady beetle (Hippodamia 

convergens) were both less sensitive to IPD072Aa than WCR, but affected at high concentrations. 

Convergent lady beetle exhibited reduced growth at 100 ng/mg, and adverse effects on survival were 

statistically significant at 1,000 ng/mg. For Pink spotted lady beetles, statistically significant reduced 

survival, weight, and time to emergence was observed at 500 ng/mg. No effects of IPD072Aa were 

observed on mealybug beetle (Cryptolaemus montrouzieri) at the concentrations evaluated. One 

representative of the Staphilinidae family, greenhouse rove beetle (Dalotia coriaria) was evaluated and 

no effects were observed up to a concentration of 1,000 ng/mg IPD072Aa. 

Pink spotted lady beetles and convergent lady beetle are beneficial predators and commonly found in 

agroecosystems feeding upon aphids and other prey species; thus, they provide a beneficial service in pest 

control. Potential IPD072Aa effects on non-target organisms are discussed below in Section 4.3.3.2–

Animal Communities.

Schellenberger et al. (2016) also tested IPD072Aa protein, at concentrations up to 875 μg/ml (ppm) in 

diet assays with several lepidopteran and hemipteran species, including black cutworm (Agrotis ipsilon

Hufnagel), corn earworm (Helicoverpa zea Boddie), European corn borer (Ostrinia nubilalis Hübner), fall 

armyworm (Spodoptera frugiperda J. E. Smith), soybean looper (Pseudoplusia includens Walker), and 

western tarnished plant bug (Lygus hesperus Knight). Tissue expression in DP23211 corn range from 

0.054 to 84 ppm across roots, leaf, grain, and pollen (Table 4-10). No mortality or inhibitory effects on 

any of these species were reported.

Current studies indicate the activity of IPD072Aa has been shown to be limited to the order Coleoptera. 

Western corn rootworm was the most sensitive species tested, followed by Mexican bean beetle, for 

mortality was affected at concentrations approximately 10 times greater than those required for western 

corn rootworm. Other representatives of the Coccinellidae showed varying levels of sensitivity to 

IPD072Aa. Statistically significant effects on survival for Convergent lady beetle (Hippodamia 
4-28

convergens) and pink spotted lade beetles (Coleomegilla maculata) were observed at concentrations > 

500 ng/mg diet. Southern corn rootworm (Diabrotica undecimpunctata) and yellow mealworm (Tenebrio 

molitor) likewise exhibited sensitivity, with survival affect at concentrations 1,000 ng/mg diet. Where 

effects on survival in these species were observed at > 500 ng/mg diet, these are dietary concentrations 

that are unlikely to be achieved in the field, considering the tissue expression levels summarized in 

Table 4-10.

While microbially produced IPD072Aa protein was used in the spectrum of activity studies, functional 

equivalency data shows that the activity of IPD072Aa is equivalent between in planta and microbially 

produced IPD072Aa protein (Pioneer 2020).

Based on these data, DP23211 corn is effective in control of WCR, with limited potential to affect other 

pest species. DP23211 corn was found to be comparable to control corn lines in respect to disease 

response (Pioneer 2020). APHIS has not identified any significant changes to agronomic practices or 

inputs, nor the DP23211 corn phenotype (other than the intended insecticidal activity) that would have 

adverse effects on plant diseases, insect pests, or their management.

4.3.2 Physical Environment

4.3.2.1 Soil Quality

Overview

Relative to crop production, concerns regarding soils are the potential for agronomic practices and inputs 

to affect soil fertility; erosional capacity; off-site transport of topsoil (sediments), pesticides, and 

fertilizers; and disturbance of soil biodiversity. Tillage, cover crops, crop rotation, irrigation, and pesticide 

and fertilizer inputs can influence the biological, physical, and chemical properties of soil and have a 

substantial impact on soil fertility and erosion (Baumhardt et al. 2015). Soil quality loss occurs through 

declines in soil organic matter (SOM), minerals (e.g., magnesium, calcium), essential nutrients (e.g., 

nitrogen, phosphorus, potassium), soil biota, and physical alteration of soil structure (compaction). 

Soil Erosion on U.S. Croplands

Due to the rate of soil formation, on the order of millimeters per year, soil is considered a nonrenewable 

resource that requires conservation and stewardship for sustainable crop production. Soil erosion not only 

increases fertilizer requirements and production costs, it leads to impaired air and water quality. Soil 

erosion occurs in all areas of the United States but is more concentrated in those regions where the 

percentage of total area in cropland is highest and a larger proportion of the land is highly erodible 

(Magleby et al. 1995; USDA-NRCS 2010; Baumhardt et al. 2015). Excessively eroding cropland soils are 

concentrated in the Midwest and Northern Plain States, to include the Corn Belt (Figure 4-11). 
4-29

Figure 4-11. Locations and Status of U.S. Croplands Subject to Erosion

Source: (USDA-NRCS 2018a)

Since 1985, conservation programs have specifically targeted highly erodible lands in the United States. 

As conservation tillage and cover cropping practices increased, soil erosion significantly declined 

(USDA-NRCS 2010, 2018b). In 1982, total annual water erosion (sheet and rill) on cultivated cropland 

was 3.82 tons per acre per year, versus 2.71 in 2015. For wind erosion, erosion rates reduced from 3.21 to 

1.91 tons per acre over the same time period (USDA-NRCS 2018b).

As of 2017 (latest survey), 41% of farmers applied continuous no-till practices, 14% rotational no-till, 

27% reduced tillage, and 4% vertical tillage (a type of conservation tillage), with only 14% using 

conventional tillage (SARE/CTIC 2017). Overall, surveyed farmers applied reduced tillage on 97.7

million acres, conventional tillage on 80 million acres, and no-till on 104.4 million acres (Table 4-11). In 

addition, they are adopting the use of cover crops to conserve soils, SOM, and soil quality (Ghabbour et 

al. 2017; SARE/CTIC 2017). 

An increase in conservation tillage has been facilitated by the availability (since the 1980s) of postemergent herbicides (Fernandez-Cornejo et al. 2012), which can be applied over crops throughout the 

growing season—not just before planting, as had previously been the case. The use of conservation tillage 

is also attributed, in part, to cultivation of HR crops, which provide for effective chemical means of weed 

control, and can reduce reliance on tillage for control of weeds (Fernandez-Cornejo et al. 2014b; Claassen 

et al. 2018). 
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Table 4-11. Tillage Practice on U.S. Cropland, 2012 – 2017

Cropland with

reduced tillage, 

excluding no-till

Cropland with notill practices 

Cropland with

intensive tillage 

practices

Cropland planted to 

a cover crop 

(excluding CRP)

2017 97,753,854 104,452,339 80,005,292 15,390,674

2012 76,639,804 96,476,496 105,707,971 10,280,793

Source: (USDA-NASS 2019a) 

4.3.2.1.1 Potential Effects on Soils

The agronomic characteristics of DP23211 corn are similar to conventionally bred varieties (Pioneer 

2020), and practices and inputs used for DP23211 corn production that can impact soil quality, namely 

tillage, chemical inputs, and cover cropping, are expected to be similar to/same as those currently used. 

Any potential impacts on soils resulting from DP23211 corn cultivation would be similar to that of other 

corn varieties. HR crops are correlated with use of conservation tillage practices, which help sustain soil 

health and water retention, and reduce runoff (NRC 2010; NAS 2016; Claassen et al. 2018). As discussed

below in Section 4.3.3.1, soil biota communities, which are primary determinants of soil quality, and in 

turn erosional capacity (Ghabbour et al. 2017), are unlikely to be affected by the PIPs in DP23211 corn. 

All farmers producing crops on highly erodible land are required to maintain and implement a soil 

conservation plan that is approved by the USDA National Resources Conservation Service (USDANRCS 2019a). These plans are prepared by the grower pursuant to the Food Security Act of 1985 (P.L. 

99-198, Farm Bill), which included a number of provisions designed to conserve soil and water resources

and minimize erosion. The 2014 and 2018 Farm Bills continued the requirement that producers adhere to 

conservation compliance guidelines to be eligible for conservation programs administered by USDA-FSA 

and USDA-NRCS. State agencies likewise provide assistance in development and implementation of soil 

conservation plans.

4.3.2.2 Water Resources 

Agronomic inputs, and in many areas tillage and irrigation, are necessary for efficient corn production. 

These practices and inputs can, however, potentially lead to the impairment of surface waters through 

runoff of pesticides, fertilizers (nutrients), and topsoil (Bricker et al. 2008; CENR 2010). Groundwater 

can also be impacted by agronomic inputs via leaching, as well as through irrigation withdraw. In many 

areas of Midwest corn yields can either be increased by irrigation, or irrigation is necessary for 

production. Irrigated corn accounts for 58% of total annual corn production in the Western U.S. Corn Belt

(Grassini et al. 2011). 

While pollutants come from various sources, the EPA’s National Water Quality Assessment finds that 

agricultural nonpoint source (NPS) pollution is a leading cause of impairment of surveyed rivers and 

streams, the third largest source for lakes/ponds, the second largest source of impairments to wetlands, 

and a major contributor to contamination of surveyed estuaries, coastal areas, and ground water (US-EPA 

2020a). The most common NPS contaminants in agricultural runoff are sediment, nutrients such as 

nitrogen and phosphorus, and pesticides (Table 4-12), all of which can adversely affect aquatic 

ecosystems.

 Table 4-12. Causes of Impairment in Assessed Rivers and Streams, 2020
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Rivers, Streams

Lakes, Reservoirs, 

Ponds Bays, Estuaries Wetlands

Miles Rank Acres Rank Miles Rank Acres Rank

Nutrients 118831 3rd 3943395 2nd 18279 2nd 67849 6th

Sediment 138874 2nd 502200 12th 400 18th 1237 15th

Pesticides 18069 16th 412672 13th 7543 8th 202 21st

Shown are national water quality data reported by the States to EPA under Section 305(b) and 303(d) of the 

Clean Water Act. The data shown is the most current available, which varies widely among states, spanning the 

years from 2004 to 2016. The EPA lists around 34 different factors that are the cause impairment of U.S. 

waters. For rivers and streams, the EPA lists sediments as the second most frequent cause of impairment, 

nutrients third, and pesticides sixteenth. For lakes, reservoirs, and ponds, nutrients are second, sediments 

twelfth, and pesticides thirteenth. For bays and estuaries, nutrients are second, sediments eighteenth, and 

pesticides 8th. For wetlands, nutrients are sixth, sediments fifteenth, and pesticides twenty-first. Source: (USEPA 2020a) 

Excess sediment in runoff can adversely affect aquatic ecosystems by covering fish breeding substrates, 

increased turbidity, and impairing growth of aquatic plants. Nutrient runoff (e.g., nitrogen and 

phosphorus) from agricultural fields contributes to eutrophication of surface waters. Sixty five percent of

U.S. estuaries have moderate to high levels of eutrophication (NOAA 2020). Eutrophic conditions cause 

impairments to human uses and living resources as a result of harmful algal blooms and hypoxic/anoxic 

conditions,

12 which lead to fish kills, fish consumption warnings, declines in tourism, and impacts on 

fisheries (Bricker et al. 2008; CENR 2010). Based on a USGS study by Munn et al. (2018) some the most 

impaired streams, as assessed by algae or invertebrate conditions, are in those areas with the greatest 

agricultural land use—primarily in the central United States, to include the Corn Belt (Figure 4-12). 

Watersheds with a high potential to discharge nitrogen and phosphorus from agriculture sites to estuaries 

are located primarily in the midwestern Unites States—Mississippi river basin—and Southern Seaboard 

regions (Wiebe and Gollehon 2006; CENR 2010; US-EPA 2020m). 

12 Hypoxia means low dissolved oxygen concentrations. Anoxia means a total depletion of dissolved oxygen. Both conditions 

are harmful to aquatic biota.
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Figure 4-12. Impaired Rivers and Streams in the United States

Based on USGS surveys conducted from 2003 to 2011, biological conditions in streams decreases as agricultural 

intensity increases in a watershed. Generally, biological condition was highest in the Western Region where the 

agricultural intensity is the lowest; conversely, biological conditions were lowest in the Central Region where 

agricultural intensity is highest. Assessing biological condition involves comparing the observed number of taxa at a 

site to the number of taxa expected based on a set of regional reference sites. A stream with a score greater than 

80 percent implies an unaltered stream, whereas a stream with a score less than 80 percent implies an altered 

biological condition. Source: (Munn et al. 2018)

Human uses impacted by impaired surface waters include commercial and recreational fishing, shellfish 

harvesting, fish consumption, swimming, aesthetics, and tourism (CENR 2010). The overall top four 

causes of these use impairments were listed as agriculture (crops and animal operations), wastewater 

treatment plants, urban runoff, and atmospheric deposition (Bricker et al. 2008; Boesch 2019). Nutrient

run-off has a major economic impact—causing an estimated $2.2 billion per year in damages related to 

recreational water usage, waterfront real estate, and drinking water treatment (Dodds et al. 2009). In all 

regions where crops are produced controlling non-point sources remain a primary focus (US-EPA 2020a, 

d).

The U.S. corn belt lies within the Mississippi River basin, which spans 1,245 million square miles across

31 states. Nitrogen and phosphorus run-off in the Mississippi River basin is particularly problematic for 

Gulf of Mexico ecosystems and fisheries (Wiebe and Gollehon 2006; US-EPA 2019d, 2020a). 

Agricultural sources contribute around 70% of the nitrogen and phosphorus delivered to the Gulf of 
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Mexico, versus 9% to 12% contribution from urban sources (Alexander et al. 2008). Corn, specifically, 

accounts for about 45% of U.S. crop acreage receiving manure, and 65% of the 8.7 million tons of 

nitrogen fertilizer applied by farmers each year (Ribaudo et al. 2011). Nitrogen run-off from cornfields in 

the Mississippi River basin is the single largest source of nutrient pollution to the Gulf of Mexico’s “dead 

zone” (Figure 4-13). The most heavily tile-drained areas are also the largest contributing source of nitrate 

to the Gulf of Mexico, leading to seasonal hypoxia (David et al. 2010). 

Figure 4-13. Agricultural Run-Off: Mississippi River Watershed

This image from a NOAA Environmental Visualization Lab animation illustrates how run-off from farms (green 

areas) and cities (red areas) drains into the Gulf of Mexico (GOM). This run-off contains nutrients from fertilizers, 

wastewater treatment plants, and other sources, which leads to hypoxic "dead zones" on an annual basis; areas in 

the GOM where the oxygen concentration is so low that aquatic biota can suffocate and die. The largest hypoxic 

zone in the United States, and the second largest hypoxic zone worldwide, forms in the northern Gulf of Mexico 

near New Orleans. Source: (NOAA 2019)

4.3.2.2.1 Water Quality Regulation

Point and Non-Point Source Discharges

Pollutant sources are classified by the EPA and state agencies as NPS and point source. NPS pollution is

the most significant source of pollution, overall (US-EPA 2020g). NPS contaminants in runoff originate 

from sources such as construction sites (e.g., residential and commercial development, construction of 

roads/highways), impervious surfaces (parking lots, roads/highways, rooftops), and crop fields and 

livestock rearing facilities. NPS pollutants include fertilizers and pesticides applied to residential, 

commercial, and agricultural sites, and sediments from the built environment and croplands, as well as 

unmanaged landscapes. The most common NPS contaminants in agricultural run-off are sediment, 

nitrogen and phosphorus, and pesticides.
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Point source pollutants are discharged from any identifiable, singular source, such as a pipe, drain, or 

vessel. Factories and sewage treatment plants are examples of point sources. Factories, such as oil 

refineries, pulp/paper mills, and chemical manufacturers typically discharge one or more pollutants in 

EPA regulated effluents. Livestock rearing facilities (e.g., dairy and beef cows, hogs, chickens) are other 

sources of point source pollution (e.g., nutrients, microbial pathogens, pharmaceuticals) (Burkholder et al. 

2007).

The Clean Water Act (CWA) established the National Pollutant Discharge Elimination System (NPDES) 

for regulation of point sources (US-EPA 2019a). Under the NPDES program, factories, certain livestock 

rearing facilities (concentrated animal feeding operations (CAFOs)), sewage treatment plants, and other 

point sources must obtain a permit from the state and EPA before they can discharge their waste or 

effluents into any body of water. Prior to discharge, the point source must use the latest technologies 

available to treat its effluents and reduce the level of pollutants. 

NPS pollution, which is the primary type of discharge from cropping systems, is not regulated under the 

CWA/NPDES permit program, rather, it is left largely to voluntary controls implemented by states and 

local authorities. Thus, most crop production activities do not require a Section 404 permit. To be exempt, 

the farming activity must be part of an ongoing farming operation, cannot be associated with bringing a 

wetland into agricultural production, or converting an agricultural wetland to a non-wetland area. While 

the CWA does not provide for direct regulation of nonpoint sources, Section 319 of the CWA created a 

federal grant program that provides money to states, tribes, and territories for developing and 

implementing NPS management programs. 

Pesticides

The EPA determines use requirements for pesticides that are intended to be protective of water quality, 

including drinking water, and to protect aquatic life (US-EPA 2019e, b). The EPA provides label use 

restrictions and guidance for product handling intended to prevent impacts to surface and groundwater. 

4.3.2.2.2 Potential Effects on Water Resources

The potential impacts of crop production on water quality primarily derive from the collective/aggregate 

inputs from crop fields into surface waters. Certain pesticides—depending on mobility and persistence 

characteristics—can leach into groundwater at sites where the pesticide is mixed or applied. Total U.S. 

corn acreage comprises round 90 million acres annually (USDA-NASS 2019a). Collectively, runoff of 

nutrients, pesticides, and topsoil from croplands can have adverse impacts on surface waters and 

nearshore coastal waters. Because the agronomic practices and inputs utilized for DP23211 corn 

production would not substantially differ from other corn varieties, the sources of potential impacts on 

water resources, namely NPS pollutants in agricultural run-off, would not substantially differ (e.g., 

sediments, fertilizers, insecticides, herbicides, fungicides). 

DP23211 corn would facilitate the use of glufosinate in lieu of other herbicides. No significant increase in 

total herbicide use (lbs a.i./year) on corn would be expected. Minor annual fluctuations in total herbicide 

use would occur due to variances in the use rates in lbs a.i./acre/year among herbicides, herbicide rotation, 

and annual acreage planted to corn. Glufosinate use would be subject to EPA label and other use 

requirements, which are in part established to be protective of water quality (US-EPA 2019b). Any 

reduced insecticide use with DP23211 corn—relative to the IR PIP traits—would reduce the risk of 
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insecticides in run-off. Adopters of IR corn crops have been found to use around 11.2% (0.013 kg/ha) 

less insecticide than nonadopters—growers of non-Bt crops (Perry et al. 2016).

4.3.2.3 Air Quality 

National Ambient Air Quality Standards 

Air pollution is inherently a problem resulting from the collective emissions of various sources. To 

protect environmental and public health the EPA, pursuant to the Clean Air Act, establishes National 

Ambient Air Quality Standards (NAAQS) that aim to limit atmospheric emissions (US-EPA 2019h). 

NAAQS are established for six criteria pollutants: ozone (O3), nitrogen dioxide (NO2), carbon monoxide 

(CO), sulfur dioxide (SO2), lead (Pb), and particulate matter (PM). In addition to criteria pollutants, the 

EPA regulates 187 hazardous air pollutants, such as ammonia and hydrogen sulfide, as well as 

greenhouse gas emissions. To help regulate emissions the EPA has categorized primary emissions sources 

into point, mobile, biogenic, and area. Point sources include major industrial facilities such as chemical 

plants, oil refineries, and power plants. Mobile sources include cars, trucks and buses and off-road 

equipment such as ships, airplanes, and agricultural and construction equipment. Area sources are defined 

as smaller operations such as dry cleaners and gas stations. Biogenic sources are comprised of vegetation, 

soils, and animals.

All areas of the United States are classified as to their consistency with the NAAQS; for example, having 

attained NAAQS, or not. States enforce the NAAQS through creation of State Implementation Plans

(SIPs), which are designed to achieve the EPA-established NAAQS. The EPA designates a region as 

being in attainment for a criteria pollutant if atmospheric concentrations of that pollutant are below the 

NAAQS, or being in nonattainment if criteria pollutant concentrations violate the NAAQS.

Crop production practices, on a regional scale, can generate air pollutants that can contribute to 

challenges in maintaining NAAQS. Agricultural emission sources from corn production include smoke 

from agricultural burning (PM); fossil fuel combustion associated with equipment used in tillage, 

pesticide application, and harvest (CO2, NOx, SOx); soil particulates from tillage (PM); soil nitrous oxide 

(N2O) and ammonia (NH3) emissions from the use of fertilizers/manure; and atmospheric emissions 

through the volatilization of pesticides, and gases from manure (Aneja et al. 2009; Hill et al. 2019; USEPA 2019g).

Prescribed burning is a land treatment used under controlled conditions to accomplish resource 

management objectives. Open combustion produces particles of widely ranging sizes, depending to some 

extent on the rate of energy release of the fire (US-EPA 2019g). The extent to which agricultural and 

other prescribed burning may occur is regulated by individual SIPs to achieve/maintain compliance with 

NAAQS. Prescribed burning of fields would likely occur only as a pre-planting option based on 

individual farm characteristics. There is no known association between prescribe burning and GM HR/IR 

crops that is unique or differs from conventional corn crops.
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While the EPA establishes NAAQS, the standards do not set emission control requirements for any 

particular industry, including agriculture.13 The USDA and EPA provide guidance for regional, state, and 

local regulatory agencies, and farmers, on how to best manage agricultural emissions sources (USDAEPA 2012). These measures allow stakeholders the flexibility in choosing which measures are best suited 

for their specific situations/conditions and desired purposes. The EPA has also developed USDAapproved measures to help manage air emissions from cropping systems to help satisfy State 

Implementation Plan requirements. The EPA recommends that in areas where agricultural activities have 

been identified as a contributor to a violation of NAAQS, USDA-approved conservation systems and 

activities be implemented to limit emissions. The USDA Environmental Quality Incentives Program Air 

Quality Initiative provides financial and technical assistance to help farmers and ranchers limit air 

pollution (USDA-NRCS 2020a).

Pesticides

Apart from NAAQS emissions, spray drift, and volatilization of pesticides from soil and plant surfaces, 

can result in the introduction of constituent chemicals into the air, which can present risks to human 

health and wildlife, non-crop plants, and nearby crops. Thus, drift and volatilization of pesticides can be a

source of concern to both farmers and the general public in regard to potential environmental and human 

health effects.

Volatilization is dependent on pesticide chemistry, soil wetness, and temperature (US-EPA 2019j). Drift 

is more likely to occur with fumigants (gasses), dusts, or when liquid pesticides are applied as a very fine 

mist (US-EPA 2019c). Certain pesticide ingredients stay in the atmosphere for only a short period of 

time, while others can persist longer (NPIC 2020). Some pesticides can give off chemicals called volatile 

organic compounds, which can react with other chemicals and form a pollutant called tropospheric ozone. 

Pesticide use accounts for about 6% of total tropospheric ozone levels (UC-IPM 2006; Zeinali et al. 

2011).

The EPA, in addition to label use requirements, introduced initiatives to help pesticide applicators 

minimize off-target pesticide drift through voluntary Drift Reduction Technology Program, which 

encourages the manufacture, marketing, and use of spray technologies that reduce pesticide drift (USEPA 2019c). The EPA also, through the National Emission Standards for Hazardous Air Pollutants 

(NESHAP), established standards to reduce emissions of hazardous air pollutants (HAP) from existing 

and new facilities that manufacture organic pesticide active ingredients used in herbicides, insecticides, 

and fungicides (US-EPA 2020f).

4.3.2.3.1 Potential Effects on Air Quality

Because the agronomic practices and inputs for DP23211 corn production would be the same as/similar to 

other corn varieties, and there would be no increase/decrease in acreage resulting from DP23211 corn 

production, no changes to emission sources (i.e., tillage, fossil fuel burning equipment, the application of 

fertilizers and pesticides), or volume of emissions from U.S. corn production, would be expected. As 

13 Many types of stationary engines exist and are found on farms, including diesel engines, spark ignited engines, 

and reciprocating internal combustion engines. Air quality requirements vary for stationary engines, depending on 

whether the engine is new or existing, where the engine is located, and what type of ignition system is used. The 

National Emission Standards for Hazardous Air Pollutants (NESHAP) for Reciprocating Internal Combustion Engines 

(RICE) are outlined in the Code of Federal Regulations under 40 CFR 63 Subpart ZZZZ.
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compared to production of non-IR corn varieties, due to fewer insecticide applications (approx. 11% 

reduction (Perry et al. 2016)) and associated fuel use, there would be, to some extent, fewer NAAQS 

pollutant emissions with DP23211 corn production.

4.3.3 Biological Resources

4.3.3.1 Soil Biota

Soil biota determine soil health, which in turn determines the efficacy by which crops can be produced 

and soil erosional capacity (FAO 2017). Soil biota consist of microorganisms (bacteria, fungi, archaea 

and algae), soil animals (protozoa, nematodes, mites, springtails, spiders, insects, and earthworms), and 

plants (e.g., algae) that live all or part of their lives in or on the soil (Fortuna 2012). Soil biota play a key 

role in the formation and cycling of soil organic matter (including mineralization), biodegradation of 

anthropogenic substances (e.g., pesticides), nutrient cycling, suppression of plant diseases, promotion of 

plant growth, soil structure formation, and most biochemical soil processes (Gupta et al. 2007; Fortuna 

2012; Parikh and James 2012). Plant roots, including those of corn, release a variety of compounds into 

the soil creating a unique environment for microorganisms in the root zone (rhizosphere). Millions of 

species of soil organisms exist but only a fraction of them have been cultured and identified (Fortuna 

2012).

Some soil borne microorganisms can cause plant diseases that can result in substantial economic losses in 

crop production. Soil borne corn diseases include fungal corn rusts, corn leaf blights, ear smuts, ear and 

kernel rot fungi, and maize mosaic viruses. Soils are commonly treated to control plant pathogens.

Relative to crop production, the main factors affecting soil biota populations and diversity are soil type 

(texture, structure, organic matter, aggregate stability, pH, and nutrient content), plant type (providing

specific root exudates and carbon and energy sources into the soil), and agricultural management 

practices (crop rotation, tillage, pesticide and fertilizer application, and irrigation) (Kowalchuk et al. 

2003; Garbeva et al. 2004; Gupta et al. 2007). Climate, particularly the moisture and heat content of soil, 

is a principal determinant of soil biological activity.

4.3.3.1.1 Potential Effects on Soil Biota

HR and IR Crops

Potential changes to the soil microbial community as a result of cultivating HR and IR crops has been of 

much research interest since their introduction in the late 1990s (e.g., (Motavalli et al. 2004; Locke et al. 

2008; Kremer and Means 2009)). Potential impacts considered include changes to the structure and 

function of microbial and insect communities near the roots of transgenic plants due to altered root 

exudation, transfer of novel proteins into the soil, or a change in microbial populations due to changes in 

agronomic practices used to produce transgenic crops (e.g., pesticide use). The majority of these studies 

have focused on Bt crops due to their insecticidal activity. Most studies to date have found no significant 

effect of Bt crop traits on soil community structures (Kowalchuk et al. 2003; Hannula et al. 2014; Zaman 

et al. 2015; Xie et al. 2016; Yasin et al. 2016). 

As summarized below, the HR and IR traits in DP23211 corn are not expected to have any significant 

long-term effects on soil biota or community structures in DP23211 corn fields. Apart from the dsRNA, 
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the introduced genes/gene products in DP23211 corn naturally occur in soils; they are derived from soilborne bacteria. 

Pat Gene and the Enzyme Phosphinothricin N-Acetyltransferase 

Phosphinothricin N-acetyltransferase (PAT) is an enzyme that confers glufosinate resistance in transgenic

plants. PAT acetylates glufosinate—changes its structure—which inhibits its herbicidal activity. The gene 

encoding the PAT protein in DP23211 corn was isolated from Streptomyces viridochromogenes, which 

occurs predominantly in soils (Liu et al. 2013; GCM 2019). The EPA conducted an ecological risk 

assessment for PAT and concluded that no unreasonable adverse effects on non-target organisms, to 

include soil biota, are expected from exposure to the PAT protein (US-EPA 2005). There are no 

identifiable risks to soil biota associated with the PAT expressed in DP23211 corn.

Phosphomannose Isomerase 

Phosphomannose isomerase (PMI) is an enzyme involved in carbohydrate metabolism and it, or

homologous enzymatic proteins, are expressed in various taxa including bacteria, fungi, insects, some 

species of plants and nematodes, and mammals—including humans (de Lonlay and Seta 2009; Hu et al. 

2016a). The PMI protein produced in DP23211 corn is encoded by the native pmi gene from E. coli

(Pioneer 2020), which commonly occurs soils. The EPA conducted an ecological risk assessment for E. 

coli derived PMI and concluded that no unreasonable adverse effects on non-target organisms, to include 

soil biota, are expected from exposure to the PMI protein (US-EPA 2005). There are no identifiable risks 

to soil biota associated with the PMI expressed in DP23211 corn.

DvSSJ1 dsRNA and IPD072Aa: Soil Degradation and Potential Risks Posed

The risks DvSSJ1 dsRNA and IPD072Aa may present to soil biota is a function of the potential hazard 

they may pose, and exposure. The transport and fate of dsRNA and IPD072Aa in soils determines the 

potential routes and duration of exposure. DvSSJ1 dsRNA and IPD072Aa will be produced continually in 

DP23211 corn, in all tissues. The primary route of direct exposure to the dsRNA and IPD072Aa trait 

protein for soil-dwelling invertebrates would be from feeding on root tissue. It is expected that potential 

exposure of soil biota to DvSSJ1 dsRNA and IPD072Aa via root tissues would be continuous, throughout 

the life cycle of DP23211 corn. It is not known whether DvSSJ1 dsRNA and IPD072Aa would be present 

in root exudates, though upon root cell lysis, small amounts of DvSSJ1 dsRNA and IPD072Aa could be 

released into the soil. Soil biota could also be exposed to dsRNA and IPD072Aa via decaying postharvest plant material left on the field, or plant material plowed into the soil. 

DNA/RNA, to include dsRNA and other small RNAs (sRNA), are continuously released into soils

through the decomposition of plants, animals, fungi, bacteria—all life forms—and common components 

of soils. Some soil microbes and macrofauna can potentially uptake exogenous (environmental) dsRNA 

and sRNA. Bacteria (prokaryotes) do not have a homologous RNAi process found in eukaryotes, and 

targeted modification of gene expression via RNAi is thus not possible (Shabalina and Koonin 2008; 

Rusk 2012). In general, environmental DNA/RNA is ubiquitous in most soil environments. Utilization of 

environmental/exogenous DNA/RNA by bacteria is for (1) horizontal gene transfer among bacteria, and

(s) as a nutrient source. Many species of bacteria actively take up DNA from their environment through a 

genetically programmed process called transformation. Natural transformation is a common mode of 

horizontal gene transfer in bacteria. It results from the intrinsic capacity of bacteria to import exogenous 
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DNA and integrate it by recombination into their chromosome (Attaiech et al. 2016). For bacteria to take 

up extracellular genetic material via transformation, it must be what is termed “competent”. Natural 

competence is the genetic ability of a bacterium to uptake environmental DNA under natural or in vitro 

conditions. Bacteria can also be made competent artificially by chemical treatment and heat shock to 

make them transiently permeable to DNA. When bacteria uptake DNA and incorporate it into their

genome, changing the cell's genotype, the bacteria is said to be transformed (Lorenz and Wackernagel 

1994; Sinha and Redfield 2012; Mell and Redfield 2014). Bacterial transformation is presumed to allow 

for bacteria populations to adapt to harsh/extreme environmental changes. 

Apart from the utilization of extracellular DNA for transformation, environmental DNA/RNA provide a

source of nucleotides—used as a nutrient source for soil microbes (Lorenz and Wackernagel 1994; Mell 

and Redfield 2014). All bacteria cells take up preformed nucleotides where possible (as opposed to de 

novo synthesis), and many species produce nucleases that degrade DNA/RNA and allow them to use the 

derived nucleic acids as nutrients (Mell and Redfield 2014). One major fate of extracellular DNA/RNA in 

in the soil environment is degradation by indigenous soil microbial extracellular deoxyribonucleases 

(exDNases) into smaller fragments (Kamino and Gulden 2021). Most intact DNA/RNA that is taken up 

by bacteria is degraded upon uptake and used as a nutrient source, even when it has sequence homology

to that of the bacterial chromosome (Mell and Redfield 2014). 

Environmental RNA uptake by eukaryotes was initially discovered in the nematode Caenorhabditis 

elegans, which uses transmembrane channel proteins to assimilate environmental RNAs, namely long 

dsRNAs (Fire et al. 1998; Winston et al. 2007; Whangbo and Hunter 2008). Some of the exogenous 

dsRNAs assimilated by C. elegans have been shown to induce gene silencing—RNAi (Wang et al. 2016). 

RNAi triggered by environmental exposure to dsRNA has also been documented in planaria and parasitic 

nematodes (Newmark et al. 2003; Orii et al. 2003; Bakhetia et al. 2005). In C. elegans, RNA uptake from 

the environment requires dsRNAs that are longer than 50 bp; shorter dsRNAs cannot be effectively taken 

up by C. elegans (Wang et al. 2016). Similarly, some fungal plant pathogens can take up long dsRNAs, 

as well as sRNAs, from the environment, though the precise mechanism for uptake remains unknown

(Wang et al. 2016). The DvSSJ1 dsRNA in DP23211 corn is 210 bp (Pioneer 2020), thus, it is 

conceptually feasible that uptake by micro- and macro-fauna could occur. 

Bidirectional cross-kingdom RNAi via transfer/uptake of sRNA among plants and plant pathogens is also 

known to occur (Wang et al. 2016). For example, plants have been found to transport sRNAs into fungal 

pathogens, using extracellular vesicles, to suppress virulence-related genes (Huang et al. 2019). 

Arabidopsis plants have similarly been shown to deliver sRNAs into an oomycete pathogen to induce 

gene silencing (Huang et al. 2019). Endogenous plant sRNAs are known to play a regulatory role in 

symbiotic plant-microbe interactions (Song et al. 2019). 

The decay rate, which determines the environmental availability of DNA/RNA in soils, is affected by 

microbial activity, pH, temperature, soil nuclease activity, the valence and concentration of cations, water 

content, and size and characteristics of the DNA/RNA (Greaves and Wilson 1970; Antheunisse 1972; 

Keown et al. 2004). As previously summarized, the majority of species of soil microbiota, such as bacilli, 

non-coryneform rods, streptomycetes, and fungi produce nucleases that degrade environmental DNA and 

RNA (Antheunisse 1972). Both DNA and RNA have been found to be fully degraded in soils, 

mineralized to nitrogen, within about 30 days (Greaves and Wilson 1970; Keown et al. 2004; Levy-Booth 
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et al. 2008). The dissipation of the DvSSJ1 dsRNA was observed to be around 80% within 24 hours, and 

90% or more at 7 days, in three soil types (loam, sandy clay loam, and silt loam) (Pioneer 2020). In 2015, 

the EPA registered a similar plant incorporated protectant in Monsanto MON87411 corn; an insecticidal 

DvSNf7 dsRNA that also targets corn rootworm. This dsRNA is of similar size and molecular 

characteristics; DvSNf7 dsRNA is 240 base pairs and DvSSJ1 dsRNA 210 base pairs. DvSnf7 dsRNA 

was undetectable after 48 hrs (Dubelman et al. 2014). Other studies found DT90 values (time to 90% 

degradation) for DvSNf7 dsRNA to be 39 and 50 hours for sandy clay and sandy soil, respectively 

(Joaquim et al. 2019). These dissipation rate estimates are comparable to those observed when DvSnf7 

dsRNA is exposed to temperate agricultural soils (DT50 < 30 hours) and suggest that the dissipation rate 

of dsRNA is largely independent of soil physical and chemical characteristics (Joaquim et al. 2019). 

DvSSJ1 dsRNA was, however, observed to be biologically active after 54 days in one study on terrestrial 

degradation. 

Given the structural and size similarities, and common processes by which DNA/RNA are degraded by

soil microbiota (e.g., nucleases), the environmental fate and degradation of DvSSJ1 dsRNA, its typical 

residence time in soil, would be expected to be around 2 weeks or less, depending on soil type and 

environmental conditions. Generally, studies have shown 90% degradation within 7 days, with only trace 

quantities of DvSSJ1 dsRNA persisting after that (Pioneer 2020).

The DvSSJ1 dsRNA targets an mRNA sequence encoding for translation of the DvSSJ1 protein, which is 

unique to WCR. Previous work with WCR (Diabrotica virgifera virgifera; Coleoptera: Chrysomelidae) 

demonstrated that at least one ≥ 21 nucleotide (nt) match must be present in DvSnf7 dsRNA of 

approximately ≥ 60 base-pairs (bp) for activity. Neither 19 nor 20 nt sequence matches were active, 

supporting that a ≥ 21 nt sequence match is required for activity (Bachman et al. 2020). Using 

bioinformatics analyses, the closest sequence match (percent identity to the 210-bp dvssj1 sequence) was 

the ssj1 homologous gene from WCR, which as intended had a 100% sequence match, and 190 21-nt 

matches. The ssj1 homologous gene from the closely related species, northern corn rootworm, shared 

97.1% sequence identity with the 210-bp dvssj1, with 135 21-nt matches. The ssj1 homologous gene from 

southern corn rootworm shared 92.9% sequence identity with 79 21-nt matches. The ssj1 homologous 

genes from the other Coleoptera within the family Chrysomelidae as well as species within the family 

Tenebrionidae, the family Coccinellidae, and the family Staphylinidae had decreasing percent identity 

with the dvssj1 mRNA sequence, ranging from 77.6% to 61.9% similarity. All Lepidoptera species tested, 

as well as the honeybee and the insidious flower bug also had lower percent identity with the 210-bp 

dvssj1 sequence, ranging from 68.1% to 60% similarity. There were zero 21-nt matches observed across 

all of the non-Diabrotica species analyzed (Pioneer 2020).

To date, there is limited data on the potential effects of DvSSJ1 dsRNA on soil biota, specifically. At 1 ng 

DvSSJ1 dsRNA/mg diet no effects on springtails (Folsomia candida) were observed—this is the only 

data on soil biota APHIS is aware of. This dietary exposure was at 33 times the worst-case estimated 

environmental concentration (Pioneer 2020). Studies evaluating a similar DvSnf7 dsRNA targeting corn 

rootworm found no effects on earthworm (Eisenia andrei), Collembola (Folsomia candida), or

microbially-mediated soil processes, nor were any adverse effects on a battery of non-target arthropods 

observed (Bachman et al. 2016). This was attributed to the limited spectrum of activity of DvSnf7 

dsRNA—its nucleotide sequence specificity for DvSnf7 mRNA (Snf7 gene) and protein translation in 

corn rootworm (Bachman et al. 2016). 
4-41

Based on these data, exposure of eukaryotic soil biota would be limited to entry of DvSSJ1 dsRNA into 

soils upon decaying plant matter, with approximately 90% of DvSSJ1 dsRNA decaying within about 7 

days. Were eukaryotic soil biota exposed to DvSSJ1 dsRNA, and assuming cell uptake, dsRNA 

recognition, and processing of sRNA into a RNA-induced silencing complex (RISC), absent a matching 

mRNA target sequence in the organism—the dvssj1 mRNA sequence— it is unlikely any potential 

hazard, alteration of physiology via RNAi, would be presented to eukaryotic soil biota. Considering all of 

the factors discussed, DvSSJ1 dsRNA would be present in soils for a short period of time and present 

negligible risk to eukaryotic soil communities, nor any risk to communities of soil bacteria. Rather, 

DvSSJ1 dsRNA would likely serve as a nucleotide (nutrient) source for soil bacteria.

The ipd072Aa gene extant in DP23211 corn was derived from an Escherichia coli protein expression 

system. It is a cloned form of the naturally occurring ipd072Aa expressed by the common soil bacterium

Pseudomonas chlororaphis (Schellenberger et al. 2016; Boeckman et al. 2019). Most Pseudomonas 

species, including P. chlororaphis, are ubiquitous in the environment—have widespread distribution in 

soil and water (Anderson et al. 2018). Considering P. chlororaphis naturally produces the IPD072Aa 

protein (Schellenberger et al. 2016), IPD072Aa protein commonly occurs in soils. Interestingly, P. 

chlororaphis has also been reported to promote plant growth, and protect plants, by producing various 

other compounds (e.g., phenazine-type antibiotics, hydrogen cyanide, chitinases, and proteases) that 

inhibit fungal growth (EFSA 2015), as well as insects and nematodes (Anderson and Kim 2018). For this 

reason, Pseudomonas chlororaphis is widely used as a soil inoculant in agriculture and horticulture on 

various cereal and vegetable crops; it can act as a biocontrol agent against certain fungal plant pathogens 

via production of phenazine-type antibiotics (Chin-A-Woeng et al. 2000; Anderson et al. 2018). Studies 

presented by Pioneer indicate that the dissipation of IPD072Aa protein in diverse soil types occurs in less 

than 7 days; the protein is therefore unlikely to persist or accumulate in soils (Pioneer 2020). 

The only soil dwelling organism evaluated to date, that APHIS is aware of, is springtail (Folsomia 

candida). There were no biologically relevant adverse effects on springtail reproduction and survival at 

500 ng IPD072Aa protein/mg diet (tissue expression levels in DP23211 corn range from about 1 ng/mg to 

84 ng/mg). As discussed later in 4.3.3.2.3.1–Non-Target Organisms, the IPD072Aa protein has 

insecticidal activity limited to species among the order Coleoptera, primarily Diabrotica species

(Schellenberger et al. 2016; Boeckman et al. 2019; Carlson et al. 2019). APHIS is unaware of any data 

describing IPD072Aa bioactivity outside the order of Coleoptera.

Based on the data reviewed, there are no identifiable risks to non-target soil biota posed by the IPD072Aa

protein expressed in DP23211 corn.

Glufosinate Use with DP23211 Corn

DP23211 corn would facilitate use of glufosinate-ammonium based herbicides. Herbicides can differ 

from each other with regard to their potential effects on soil biota relative to their biological activity 

(mode of action) and environmental behavior (Wolmarans and Swart 2014; Dennis et al. 2018).

Herbicides used at normal field application rates—in part because their modes of action target plant 

specific physiological processes—generally have no major long-term effect on soil biota (Busse et al. 

2001; Zabaloy et al. 2008; Rose et al. 2016; Nguyen et al. 2018). Most herbicides are degraded by and 

serve as sources of carbon, nitrogen, and phosphorus for soil microorganisms. A global review by the 
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Food and Agriculture Organization (FAO) likewise found that there is limited evidence that the observed 

effects of herbicides on soil organisms have led to significant and long-lasting decreases in soil functions 

(FAO 2017). Some herbicides can however transiently effect soil organisms, namely shifts in community 

structure, and associated soil biochemical and enzymatic processes (Bünemann et al. 2006; FAO 2017).

Studies on the effects of glufosinate based herbicides on soil communities are limited. Among those that 

have been conducted, no significant adverse effects on the composition of soil bacterial and archaeal 

communities, or nematode communities, have been identified (Tothova et al. 2010; Dennis et al. 2018).

Studies by Dennis et al. (2018) found that recommended treatments of glufosinate in the form of Basta® 

and Liberty® have been shown to have negligible effects on microbial community composition, or 

microbial enzyme activity. Using microbe sequencing technologies, a study by Tang et al. (2019)

concluded that glufosinate (Basta®) application had no adverse effects on the rhizosphere bacterial 

community composed of a wide variety of phyla, including proteobacteria, bacteroidetes, acidobacteria, 

gemmatimonadetes, and actinobacteria. Mandl et al. (2018) found shifts in community structures with the 

use of glufosinate. Composition of soil bacteria and archeobacteria communities in vineyard rows after 

mechanical weeding and three herbicide treatments (glyphosate, glufosinate, and flazasulfuron) were 

evaluated. Interestingly, next-generation sequencing analyses showed that abundances of soil bacteria 

under all herbicide treatments were on average 264% higher than under mechanical weeding (Mandl et al. 

2018); this was presumed to be due to soil biota use of the herbicide active ingredient, or other 

ingredients, or both, as carbon/energy sources. However, due to high data variability this increase in 

microbial biomass was not statistically significant. Glufosinate, as other herbicides, can stimulate or 

suppress certain fungi, in particular, which suggests that herbicide-specific active ingredients, adjuvants, 

or other herbicide ingredients might be responsible for this effect (Mandl et al. 2018). Whether such shifts 

in soil fungal species composition has adverse effects on soil processes and health is unknown—it has not 

been well studied. 

While the application of glufosinate may lead to temporary variations in species composition—and 

thereby biomass, enzymatic activity, and soil respiration—the resiliency of soil organisms, and functional 

redundancy across various taxa, serve to limit the long-term effects of herbicides on soil ecosystem 

processes (Locke and Zablotowicz 2004; FAO 2017). Any exposure of soil biota to glufosinate would be 

transient and short-lived. For glufosinate, and most all other herbicides, soil microbial degradation is the 

primary process by which it is degraded in the environment. The aerobic half-life for glufosinate in soil is 

typically 3-11 days with an anaerobic half-life of 5-10 days. Field dissipation half-lives of 6-20 days (avg.

13 days) are typical (TOXNET 2020). All pesticide use on DP23211 corn would be subject to EPA label 

use requirements.

4.3.3.2 Animal Communities

4.3.3.2.1 Birds and Mammals 

Commercial cornfields, which are intensively cultivated, provide less habitat for wildlife than undisturbed 

lands. As such, the types and numbers of animal species found in and near cornfields will be less diverse. 

Cornfields can, however, provide food and cover for wildlife, such as for birds, as well as large and small 

mammals. 
4-43

Following harvest, it is common to find large flocks of migratory bird species foraging in cornfields, such 

as Canada geese (Branta canadensis), snow geese (Chen caerulescens), sandhill cranes (Grus 

canadensis), and various other species (Best et al. 1990; Taft and Elphick 2007; Sherfy et al. 2011). The 

types and numbers of birds that inhabit cornfields will vary regionally and seasonally.

A variety of mammals may forage on corn at various stages of plant growth. Large- to medium-sized 

mammals that are common foragers of cornfields include those in Table 4-13. The most notable of these 

is the white-tailed deer that inhabit woodlots adjacent to cornfields and frequent corn fields for both food 

and cover, especially in mid-summer. Agricultural crops, particularly corn and soybean, comprise a major 

portion of deer diets in Midwestern agricultural regions; deer are considered responsible for more corn 

damage than any other wildlife species (MacGowan et al. 2006). Losses to crop yield from feeding by 

raccoons have also been documented (Beasley and Rhodes Jr. 2008). Mature corn has been shown to 

constitute up to 65% of the diet of raccoons in some areas prior to harvest (MacGowan et al. 2006). As 

with larger mammals, small mammals may use cornfields for shelter and forage (USDA-NRCS 1999; UIllinois-Ext 2000; Sterner et al. 2003). 

Table 4-13. Animals Commonly Found in Corn Fields

Birds Mammals

Common Name Scientific Name Common Name Scientific Name

Red-winged blackbird Agelaius phoeniceus Large Mammals

Grackle Quiscalus quiscula White-tailed deer Odocoileus virginianus 

Horned lark Eremophila alpestris Raccoon Procyon lotor 

Brown-headed cowbird Molothrus ater Wild boar Sus scrofa 

Vesper sparrow Pooecetes gramineus Woodchuck Marmota monax 

Ring-necked pheasant Phasianus colchicus Small Mammals

Wild turkey Meleagris gallopavo Deer mouse Peromyscus maniculatus 

American crow Corvus brachyrhynchos House mouse Mus musculus 

Blackbird Turdus merula Meadow vole Microtus pennsylvanicus 

Various quail species Coturnix spp. Ground squirrel Spermophilus tridecemlineatus 

Source: (Fleharty and Navo 1983; ODNR 2001) 

4.3.3.2.2 Invertebrates 

Although certain invertebrates in corn fields are considered pests, such as the European corn borer 

(Ostrinia nubilalis) and corn rootworm (Diabrotica spp.), the majority are beneficial, performing valuable 

functions; they pollinate plants, contribute to the decay and processing of organic matter, reduce weed 

seed populations through predation, cycle soil nutrients, and prey on other insects and mites that are 

considered plant pests (Landis et al. 2005). Some of these beneficial species include the convergent lady 

beetle (Hippodamia convergens), carabid beetles, caterpillar parasitoids (e.g., Macrocentrus cingulum), 

and predatory mite (Phytoseiulus persimilis) (Landis et al. 2005; Shelton 2011). Earthworms, termites, 

ants, beetles, and millipedes contribute to the decay of organic matter and the cycling of soil nutrients 

(Ruiz et al. 2008). 

4.3.3.2.3 Potential Effects on Animal Communities

DP23211 corn cropping systems would not be expected to affect vertebrate animal communities any 

differently from that of current corn cropping systems. As summarized in Section 4.3.3.1–Soil Biota, and 
4-44

Section 4.3.4.2–Safety of the Herbicide Resistance and Insect Resistance Traits, it is unlikely PAT nor 

PMI present any hazard to wildlife. DvSSJ1 dsRNA expressed in DP23211 corn has been shown to 

primarily affect a subset of arthropods—Diabrotica species within the Chrysomelidae family of 

Coleoptera (Hu et al. 2019). The IPD072Aa protein expressed in DP23211 corn has likewise been shown 

to primarily affect Diabrotica spp. (Boeckman et al. 2019). A review of the potential risks of DvSSJ1 

dsRNA and IPD072Aa protein to non-target arthropods is provided below. 

The potential impacts of glufosinate use on wildlife have been assessed by the EPA as part of the 

pesticide registration process (US-EPA 2016e). Glufosinate use with DP23211 corn would be subject to 

the EPA label and other use requirements. 

4.3.3.2.3.1 Non-Target Organisms

The potential risk to non-target organisms, as a matter of hazard assessment, would be from exposure to 

the trait genes and gene products via consumption of the kernel, leaf, pollen, or root tissues. Invertebrate 

kernel and leaf feeders are primarily members of four insect orders: Lepidoptera (larval butterflies and 

moths), Coleoptera (beetles), Hymenoptera (larval wasps) and Orthoptera (grasshoppers). Many 

invertebrates such as honeybees, wasps, and beetles feed upon pollen. Invertebrate root feeders are 

primarily among the order Coleoptera. The most ecologically relevant route of exposure for soil-dwelling 

organisms, such as earthworms and Collembola, is considered primarily to be from root tissue or root 

exudates, with some addition of post-harvest decaying plant tissue that enters the soil (Bachman et al. 

2016). 

DP23211 produces the insecticidal protein IPD072Aa, insecticidal dsRNA targeting Dvssj1, the PAT 

protein for tolerance to glufosinate herbicides, and the PMI protein that was used as a selectable marker 

during the plant transformation process. PAT and PMI are not known to be toxic to any nontarget 

organisms beneficial to agriculture. PAT and PMI are present in numerous deregulated crop plants that 

are commercially available to growers (ISAAA 2022). Therefore, this part of the assessment focuses on 

the novel insecticidal compounds produced by DP23211 corn. 

When rats and broiler chickens were fed grain from DP23211 corn, which expresses both the IPD072Aa 

protein and dsRNA of DvSSJ1, no adverse effects were observed (Smith et al. 2021). In summary, these

studies suggest no adverse impacts to humans and vertebrate non-target organisms due to the insecticidal 

compounds produced by DP23211; therefore, subsequent analyses below focus primarily on invertebrate 

non-target organisms.

DvSSJ1 dsRNA: Terrestrial Biota

RNA interference (RNAi) is a conserved gene-silencing mechanism—across the plant and animal 

kingdoms—initiated by double-stranded RNA (dsRNA) (Fire et al. 1998; Shukla et al. 2020). One of the 

primary functions of RNAi is the protection of the genome against invasion by mobile genetic elements 

such as transposons and viruses, which can produce aberrant RNA or dsRNA in the host cell (Jensen et al. 

1999; Ratcliff et al. 1999; Elbashir et al. 2001). In general, mRNA silencing provides protection against 

diverse RNA viruses in many eukaryotic organisms (Ding 2010; Llave 2010; Qu 2010), to include 

mammals (Schuster et al. 2019). Specific mRNA degradation prevents transposon and virus replication—

although it is noted that some viruses are able to overcome or prevent this process by expressing proteins 

that suppress posttranscriptional gene-silencing (Lucy et al. 2000; Voinnet et al. 2000). 
4-45

The presence of DsRNA in a cell can trigger the specific degradation of mRNAs with homologous 

nucleotide sequences after being recognized and processed into smaller 21–23 nucleotide (nt) RNA 

fragments (Zamore et al. 2000). Different types of small RNAs (sRNA) have been identified over the 

years, of which microRNAs (miRNAs) and small-interfering RNAs (siRNAs) are the main types (Knip et 

al. 2014). sRNAs are typically 21–23 nt long (although can range from 19–25 nt) and produced from 

larger dsRNA or hairpin RNA (hpRNA) by Dicer or Dicer-like proteins. sRNAs then associate with 

Argonaute proteins to from what is called an RNA-Induced Silencing Complex (RISC). Posttranscriptional gene silencing (RNAi) in cells via a RISC involves mRNA cleavage and inhibition of 

protein synthesis (translation). This process of RNAi via RISC is widely conserved in eukaryotes (plants 

and animals); the RNAi process is also highly specific, based on the particular 21–23 nt sequence (Castel 

and Martienssen 2013; Martínez de Alba et al. 2013; Knip et al. 2014). 

The DvSSJ1 dsRNA in DP23211 corn was developed to target and inhibit dvssj1 mRNA expression in 

western corn rootworm (Diabrotica virgifera virgifera). The dvssj1 and dvssj2 genes in corn rootworm

encode cell membrane proteins associated with smooth septate junctions, which are cell-to-cell structures

that are required for gut cell integrity and function in arthropods. When ingested by corn rootworm, plantderived DvSSJ1 dsRNA is processed into 21-nt siRNAs, which decreases synthesis of DvSSJ1 protein in 

WCR via RNAi. Loss of DvSSJ1 protein production in the gut cells of WCR disrupts the formation and 

maintenance of the smooth septate junction complex, leading to loss of cell barrier integrity and larval 

mortality (Hu et al. 2019). Expression of DvSSJ1 dsRNA in DP23211 corn tissues is provided in Table 

4-14. 

 Table 4-14. DvSSJ1 dsRNA: Tissue Expression Levels in DP23211 corn*

ng/mg tissue Fresh Weight ng/mg tissue Dry Weight

(parts per million; ppm)

Root 0.00019 - 0.00877 0.00150 - 0.0944

Leaf 0.00177 - 0.0379 0.00240 - 0.0985

Grain 0.00102 - 0.0073 0.00122 – 0.0109

Pollen 0.000330 – 0.00096 0.000561 – 0.00202

Whole Plant 0.00153 - 0.0120 0.00459 - 0.0359

Forage 0.00264 – 0.0177 0.00977 – 0.0565

 *Range of tissue expression levels from V6 to R6 growth stages

For non-target organisms (NTOs) to be adversely affected by dsRNA, NTOs must possess a genetic 

sequence matching the dsRNA, and ingest it in sufficient quantities to elicit an RNAi response. Exposure 

can occur when NTOs feed directly on plant material, consume prey that ingested the dsRNA, or are 

exposed through root exudates. Evaluation of DvSSJ1 dsRNA activity in representative NTOs, including 

pollinators and pollen feeders, soil-dwelling organisms, and predators and parasitoids was conducted 

using diet-based bioassays. The DvSSJ1 dsRNA median lethal concentration (LC50), no observed effect 

dose (NOED), no observed dietary dose (NOEDD), or no observed effect concentrations (NOEC) were 

determined for the NTOs listed in Table 4-15. Note that lyophilized DP23211 corn tissue incorporated 

into insect diets was used for the DvSSJ1 dsRNA bioassays (Pioneer 2020). This methodology is 

considered to provide more consistent data as the DvSSJ1 dsRNA protein concentrations in fresh corn 

tissue can add variability to the data due to varying levels of moisture and range of DvSSJ1 dsRNA 

expression among corn tissues. 
4-46

Table 4-15. DvSSJ1 dsRNA: Spectrum of Activity in Representative Non-Target Organisms

Class Order Family Species Common 

Name

Bioassay 

Duration

(days)

Endpointsa Test Dose/

Dietary 

Concentration

Insecta Hymenoptera Apidae Apis 

mellifera

Honeybee 

(larvae)

22 LPS, AE, AW 4.0 ng/larvab

Insecta Hymenoptera Apidae Apis

mellifera

Honeybee

(adult)

14 W, AS 26 ng/bee/dayc

EntomobryomorphaCollembola Isotomidae Folsomia

candida

Springtail 28 R, AS 1 ng/mg dietd

Insecta Neuroptera Chrysopidae Chrysoperla 

rufilabris

Green 

Lacewing

21 AS, P 1 ng/mg dietd

Insecta Coleoptera Coccinellidae Coleomegill

a maculata

Pink spotted

Lady Beetle

28 AS, W, DE 1 ng/mg dietd

Insecta Coleoptera Coccinellidae Hippodamia 

convergens

Ladybird

Beetle

28 AS, W, DE 1 ng/mg dietd

Insecta Hymenoptera Eulophidae Pediobius 

foveolatus

Parasitic

Hymenoptera

14 AS 1 μg/ml dietd

Aves Galliformes Odontophoridae Colinus

virginianus

Northern 

bobwhite

quail

14 AS, AB, T >105 mg/kg 

body weighte

a. LPS = Larval and Pupal Survival, AE = Adult Emergence, W = Adult Weight AW = Adult Weight at emergence, AS = 

Adult Survival, R = Reproduction, P = Pupation, DE = Days to Emergence, AB = Abnormal Behavior, T = Toxicity 

b. NOED – No Observed Effect Dose 

c. NOEDD – No Observed Effect Diet Dose 

d. NOEC – No Observed Effect Concentration. For pink spotted lady beetle 10.3% mortality was observed at 1

ng/mg diet, although not statistically significant (P = 0.1124) 

e. LD50 – Median Lethal Dose 

Source: (Pioneer 2020) 

Similar to that reviewed for corn insect pests in 4.3.1.3 – Potential Effects on U.S. Corn Production, the 

specificity of DvSSJ1 dsRNA, observed effects on NTOs, was limited to Diabrotica species. No other 

Coleoptera or Lepidoptera species evaluated were affected by exposure to DvSSJ1 dsRNA. Thus, the 

spectrum of activity of DvSSJ1 dsRNA—its specificity—appears to be primarily limited to western corn 

rootworm, namely dvssj mRNA. Based on the data summarized in Table 4-15, adverse effects on NTOs 

via exposure to DvSSJ1 dsRNA would not be expected. 

Four species representing the predator and parasitoid group were assessed: two Cocinellidae (Ladybugs; 

C. maculata and H. convergens), one Neuroptera (net-winged insects; C. rufilabris), and one 

Hymenoptera (parasitic wasp; P. foveolatus). Additionally, one surrogate non-target soil dweller 

(springtail; F. candida) was assessed. No effects on survival were observed for any of these species. 

Honeybees consume both pollen and nectar from flowers. Nectar provides carbohydrates and small 

amounts of other nutrients, while pollen provides the bulk of the honeybee’s protein and lipid 

requirements (Carroll et al. 2017). Individual bees consume no more than a few mg during a feeding 

event (Carroll et al. 2017). Average pollen consumption by bees is generally reported to be around 3.4 to

3.9 mg/bee/day (see review by Rodney and Purdy (2020)). For DP23211 corn, the maximum 
4-47

concentration of DvSSJ1 dsRNA in pollen is very low relative to expression in other tissues. The 

maximum concentration of DvSSJ1 dsRNA in DP23211 corn pollen is 0.00096 ng/mg. For honeybee, 

there were no observed effects at 4.0 ng/larva, or 26 ng/bee/day. Assuming larva consume 2 mg of pollen

(= 0.002 ng DvSSJ1 dsRNA), the observed no effect dose of 4.0 ng/larva is 2000 times the potential 

exposure level to DvSSJ1 dsRNA. For adult honeybees, assuming consumption of 10 mg pollen (=0.0096 

ng DvSSJ1 dsRNA), or around twice the reported consumption rates, the observed no effect dose of 26 

ng/bee/day is 2,700 times the potential exposure to DvSSJ1 dsRNA. Considering these data—DvSSJ1 

dsRNA specificity for Diabrotica species, and no observed effects on Apis mellifera or other species

reviewed—the risks of DP23211 corn pollen presenting any hazard to species of Apidae (bees) is 

considered unlikely.

The molecular target of DvSSJ1 dsRNA, smooth septate junction protein 1 (dvssj1 mRNA), is arthropodspecific; it has not been identified in vertebrates (Hu et al. 2016b). Bioinformatic sequence comparisons 

of DvSSJ1 dsRNA 21 nucleotide (21-nt) small interfering RNA (siRNA) with mammalian, avian, and 

fish transcriptomes identified no 21-nt siRNA exact matches (Mirsky 2019). Sequence comparison of the 

210-bp dvssj1 (dsRNA) sequence to ssj1 homologous genes among Coleoptera, Lepidoptera, 

Hymentoptera, Hemiptera found 100%, 97.1%, and 92.9% identity for western, northern, and southern 

corn rootworm, respectively. The next closest matches were crucifer flea beetle (77.6%), striped flea 

beetle (76.2%), and Colorado potato beetle (73.3%). All other sequence matches among Coleoptera, 

Lepidoptera, Hymentoptera, and Hemiptera species evaluated were below 70% (Pioneer 2020).

Based on these data, summarized in Table 4-15, the DvSSJ1 dsRNA expressed in DP23211 corn would

not be expected to present any hazard to NTO populations— adverse effects on NTOs via exposure to 

DvSSJ1 dsRNA would not be expected. The DvSSJ1 dsRNA appears to be highly specific for Diabrotica 

virgifera vergifera. The only other species showing sensitivity to DvSSJ1 dsRNA was southern corn 

rootworm, which was observed to have decreased survival at a concentration of 100 ng DvSSJ1 

dsRNA/ml diet.

A similar RNAi PIP introduced into a commercial corn variety, SmartStax® corn, was evaluated for 

potential off-target effects. SmartStax® corn expresses a DvSnf7 RNA that likewise targets corn 

rootworm using a similar MOA—disruption of protein synthesis in the gut epithelium of Coleoptera 

species. The MOA of DvSnf7 RNA has been well characterized and shown to, likewise, have a narrow 

spectrum of activity within Diabrotica species (Bolognesi et al. 2012). The potential effects of DvSnf7 

RNA on NTOs included a pollinator (honey bee, Apis mellifera), six beneficial insect species that 

function as biocontrols (parasitic wasp (Pediobius foveolatus), ladybird beetle (Coleomegilla maculata), 

carabid beetle (Poecilus chalcites), rove beetle (Aleochara bilineata), green lacewing (Chrysoperla 

carnea), and insidious flower bug (Orius insidiosus)), soil biota (earthworm (Eisenia andrei) and

Collembola (Folsomia candida)), and microbially-mediated soil processes (Bachman et al. 2016). 

Laboratory tests evaluated ecologically relevant endpoints such as survival, growth, development, and 

reproduction and were of sufficient duration to assess the potential for adverse effects. Survival, growth 

and/or developmental observations were examined in the ladybird beetle, carabid beetle, insidious flower 

bug, honey bee, and vertebrate studies. Survival and reproduction were evaluated with Collembola, rove 

beetle and green lacewing, and survival and biomass with earthworm. All NTO bioassays were conducted 

with diet-incorporation methodology and the organisms fed as much as much as desired (ad libitum). No 

adverse effects were observed with any species tested at, or above, the maximum expected environmental 
4-48

concentration (MEEC). All margins of exposure for NTOs were >10-fold the MEEC (Bachman et al. 

2016). 

The EPA reviewed NTO hazard data for DvSnf7 (SmartStax® corn) on two species of birds, two 

mammal species, a freshwater fish, seven species of non-target arthropods, an earthworm, and honey 

bees. The EPA also included assumptions about common barriers to dsRNA uptake in vertebrates and 

bioinformatics analyses. Based on these data, the EPA concluded that adverse effects to NTOs would not 

be expected to result from cultivation of corn comprised of DvSnf7 dsRNA (US-EPA 2016c). 

The studies summarized for SmartStax® corn, examining the potential effects of DvSSJ1 dsRNA and 

DvSnf7 dsRNA on corn rootworm and NTO species support the concept that dsRNA constructs can be 

highly specific with targeted effects on a limited spectrum of insect pest species. 

IPD072Aa Protein: Terrestrial Biota

The ranges of IPD072Aa protein expression in DP23211 corn leaf, root, grain, and pollen tissues over the 

course of the growing season are summarized in Table 4-16. 

 Table 4-16. IPD072Aa Tissue Expression Levels in DP23211 Corn*

 ng/mg Tissue Dry Weight 

(parts per million; ppm)

Root 0.93 - 84

Leaf 0.054 - 39

Grain 0.51 – 4.8

Pollen 0.14 – 1.3

Whole Plant 1.7 - 24

Forage 0.51 - 28

 *Range of tissue expression levels from V6 to R6 growth stages. 

 Source: (Pioneer 2020) 

Evaluation of the potential effects of IPD072Aa protein on NTOs across several orders/families, including 

pollinators and pollen feeders, soil-dwelling organisms, and predators and parasitoids was conducted 

using diet-based bioassays (Table 4-17). The IPD072Aa protein used in the bioassay studies was 

extracted from lyophilized DP23211 corn tissue and reconstituted in an artificial diet. The targeted 

IPD072Aa protein concentrations in treatment diets used in the bioassays were based on ng/mg 

IPD072Aa in the diet wet weight (Pioneer 2020). As with the DvSSJ1 dsRNA bioassays, this 

methodology is intended provide more accurate data than use of fresh DP23211 corn tissue-based diets. 

The NTO bioassay studies indicate that IPD072Aa primarily affects species within the order Coleoptera, 

with no activity observed within tested species among the orders Lepidoptera, Hymenoptera, Collembola, 

Neuroptera, Hemiptera, or Galliformes (Schellenberger et al. 2016; Boeckman et al. 2019). 

Table 4-17. IPD072Aa Protein: Spectrum of Activity in Representative Non-Target Organisms 

Class Order Family Species Common 

Name

Study

(days)

Endpointa Test Dose/

Dietary 

Concentration
4-49

Insecta Hymenoptera Apidae Apis mellifera Honeybee 

(larvae)

22 LPS, AE, AW 200 ng/larvab

Insecta Hymenoptera Apidae Apis

mellifera

Honeybee

(adult)

10 AS, W 1300 ng/bee/dayc

Entomobry

o-morpha

Collembola Isotomidae Folsomia candida Springtail 28 R, AS 500 ng/mg diete

Insecta Neuroptera Chrysopidae Chrysoperla 

rufilabris

Green

Lacewing

21 AS, P 500 ng/mg diete

Insecta Coleoptera Coccinellidae Coleomegilla

maculata

Pink spotted

lady beetle

28 AS,W,AE 100 ng/mg diete

Insecta Coleoptera Coccinellidae Hippodamia

convergens

Convergent

ladybird

beetle

28 AS, 

W, AE

500 ng/mg diete

100 ng/mg dietf

Insecta Hymenoptera Eulophidae Pediobius 

foveolatus

Parasitic

wasp

7 AS 1000 μg/ml diete

Aves Galliformes Odontophoridae Colinus 

virginianus

Northern

bobwhite 

quail

14 AS, AB, T >2000 mg/kg 

body weighte

Mammalia Rodentia Muridae Mus musculus Mouse 14 AS, T >2000mg/kg

body weight

a LPS = Larval and Pupal Survival, AE = Adult Emergence, AW = Adult Weight at emergence, W = Adult Weight, AS = Adult 

Survival, R = Reproduction, P = Pupation, DE = Days to Emergence, AB = Abnormal Behavior, T = Toxicity 

b NOED – No Observed Effect Dose 

c NOEDD – No Observed Effect Diet Dose 

d NOED – No Observed Effect Dose 

e NOEC – No Observed Effect Concentration. For pink spotted lady beetle 26.7% mortality was observed at 500 ng/mg 

IPD072Aa diet, and statistically significant (P=0.045). Weight was affected at 500 ng/mg diet (P=0.007). Adult emergence was 

affected at 500 ng/mg (P=0.0015). A statistically significant difference was observed in mortality between convergent ladybird

beetle fed the test diet containing 1000 ng IPD072Aa protein per mg diet. Convergent ladybird beetle fed 500 ng/mg and 1000 

ng/mg (median 17 and 22 days, respectively) had significantly greater probability to take longer to emerge.

f For convergent lady beetle, statistically significant effects on weight were observe at all doses.

Source: (Boeckman et al. 2019; Pioneer 2020)

Based on the expression level of the IPD072Aa protein in DP23211 corn pollen (0.14 – 1.3 ng/mg), no 

observed effects doses summarized in Table 4-17, and pollen consumption rate of honeybees, 

summarized following, the IPD072Aa protein would not be expected to present any hazard to honeybees. 

Bees have been reported to consume on average around 3.4 to 3.9 mg pollen/bee/day (see review by 

(Rodney and Purdy 2020)). Worker honeybee larvae under experimental conditions have been observed 

to consume a total amount of 1.5 mg to 2 mg corn pollen during development (Babendreier et al. 2004). 

Maximum consumption by larva—during development, which lasts about six days—would be about 2.6 

ng IPD072Aa protein /larva. Maximum consumption by adult bees would be about 5 ng IPD072Aa 

protein/bee/day. The NOED are 200 ng IPD072Aa/larva and 1,300 ng IPD072Aa/bee/day, which are 77 

and 260 times potential dietary exposure, respectively. 

Two surrogate species representing predator and parasitoid groups were assessed: Green lacewing (C. 

rufilabris: Neuroptera) and parasitic wasp (P. foveolatus: Hymenoptera). No effects on survival or 
4-50

pupation were observed for green lacewing at 500 ng/mg IPD072Aa diet. Similarly, no effects on survival 

were observed for the parasitic wasp at 1000 ng/mg diet.

IPD072Aa has been found to affect the survival, weight, and emergence time of pink spotted lady beetles 

(Coleomegilla maculata De Geer; Coleoptera) and convergent lady beetles (Hippodamia convergens: 

Coleoptera), albeit at dietary concentrations that would be difficult to achieve in the field. Both are 

beneficial predators that feed upon aphids and other insect pest species. Convergent lady beetles will also 

feed on pollen and nectar from flowers when prey is scarce. Statistically significant effects on convergent 

lady beetle weight were observed at 100 ng/mg and above (Table 4-17). For pink spotted lady beetles, 

there was no significant effect of IPD072Aa at 100 ng/mg on survival, growth, or days to adult 

emergence, although statistically reduced survival was observed in pink spotted lady beetles at the 500 

and 1,000 ng/mg concentrations (Pioneer 2020). No effects on survival were observed in experiments 

with convergent lady beetle exposed to 100 and 500 ng/mg IPD072Aa; however, survival was reduced at 

1,000 ng/mg. Convergent lady beetle exposed to 500 and 1,000 ng/mg IPD072Aa showed reduced growth 

and required longer to emerge as adults (Pioneer 2020).

Lundgren et al. (2005) estimated that spotted lady beetle (Coleomegilla maculata) consumed 0.66, 1.67 

and 3.30 mg of corn pollen per day (over a 24 hour period) during the second, third, and fourth stadia, 

respectively. Adults consumed an estimated 13.15 mg/day during flowering (anthesis), which for corn can 

last for approximately 8 days. The observed IPD072Aa expression levels in pollen were 1.3 ng/mg dw or 

less. Adults consuming 13 mg/day of DP23211 corn pollen would intake approximately 17 ng IPD072Aa

total. Based on a No Observed Effect Diet Dose of 100 ng/mg IPD072Aa for Coleomegilla maculata, 

there are no adverse effects on Coleomegilla maculata populations that would be expected to arise from

feeding on DP23211 corn pollen. For convergent lady beetle it is noted that weight was affected at all 

experimental exposure concentrations of 100 ng/mg IPD072Aa and above (Pioneer 2020). However, 

assuming similar pollen consumption rates (13.15 mg/day), it is improbable that convergent lady beetles 

would be exposed to this level of IPD072Aa via pollen consumption. APHIS is unaware of any specific 

data as to the amount of pollen consumed by convergent lady beetles (Hippodamia convergens), although 

it is surmised pollen intake would be similar to that of the pink spotted lady beetle given the overall 

similarity of their dietary preferences (e.g., aphids and other soft-bodied insects, pollen when prey is 

scarce).

Lady beetles may also be exposed to IPD072Aa by feeding on prey that have consumed DP23211 corn 

leaf or kernel tissue (maximum expression of 39 ng/mg IPD072Aa in leaf (dw)). Much of the lady beetle 

diet is comprised of sucking insects (e.g., aphids, spider mites, scale insects, thrips) that feed on plant sap 

or other fluids from the phloem sieve tube or xylem of the plant, respectively. Aphididae feed exclusively 

upon sap in the plant sieve tube (or sieve element; SE) where they ingest sugars, nitrogen compounds, and 

other nutrients. The xylem in plants is the main conduit for water, minerals, and other compounds from 

roots to shoots. Other insects, such as the leaf hopper, feed from the xylem. 

There is currently no data on the amount of IPD072Aa that may be present in corn phloem sap or xylem 

fluids. Hence, an accurate assessment of potential lady beetle exposure to IPD072Aa via consumption of 

prey that have fed upon DP23211 corn phloem sap or xylem is not possible. Bearing this limitation in 

mind a review of potential lady beetle exposure to IPD072Aa via consumption of prey is provided.
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The phloem sap and xylem fluid both play key roles in long and short distance transport of compounds

vital to plant development, maintenance, and defense. Sugars, potassium, and amino acids are the main 

nutritional components for aphids that are commonly found in phloem sap (Sjolund 1997). The xylem 

transports water, minerals, metabolic products, and signaling compounds from the root to the shoot 

(Peuke 2009). These plant fluids also contain/transport proteins which are vital to plant physiology and 

health, protecting against local and systemic pathogen infection (Dinant et al. 2010). A comparison of the 

proteomes of the these fluids indicates that although functional categories are somewhat similar, proteins 

are likely to be fluid-specific, except for a small group of proteins present in both fluids, which may have 

a universal role, such as in cell wall maintenance and defense (Rodríguez-Celma et al. 2016). 

The phloem sap of corn has not been well studied, although various studies have quantified the phloem 

sap protein content of rice, melon, cucumber, pumpkin, canola, and castor bean plant (e.g., see (Sjolund 

1997; Dinant et al. 2010)). Several hundred phloem sap proteins have been identified among these species

(Turgeon and Wolf 2009), to include transcripts encoding proteins related to metal homeostasis, stress 

response, protein degradation or turnover, and phloem structure and metabolism (Turgeon and Wolf 

2009). Current studies have provided accumulating evidence that proteins and other macromolecules may

sporadically appear in phloem sap (e.g. in response to stress of infection), while a large number of RNAs 

and soluble proteins are constantly present in phloem sap (Hayashi et al. 2000; Walz et al. 2004). Most of 

the identified phloem sap proteins repeatedly occur in more than one plant species; this indicates a high 

degree of conservation of the phloem sap protein composition in higher plants (Kehr 2006).

Because mature sieve element (SE) cells, which form the phloem sieve tube, lack the capability for 

protein synthesis (Sjolund 1997; Kehr 2006), phloem sap proteins are believed to be synthesized and 

imported through specialized, adjacent companion cells (CCs) (Kehr 2006). In general, there are studies 

that indicate that protein movement in and out of the phloem, protein occurrence in the phloem, is an 

active transport, highly regulated event (Turgeon and Wolf 2009; Yesbergenova et al. 2016). 

There is a high degree of conservation of the phloem sap and xylem fluid proteins in higher plants—

constitutively expressed proteins, signaling compounds, and plant nutrients are actively and selectively 

secreted into and out the plant phloem and xylem (Alvarez et al. 2006; Kehr 2006; Djordjevic et al. 2007; 

Turgeon and Wolf 2009; Neumann et al. 2010). While IPD072Aa is not a normal component of 

constitutively expressed proteins in corn, present in the sap of the phloem sieve tube or xylem fluid,

whether it may occur in phloem sap and xylem fluid is unknown as IPD072Aa content in the phloem sap

and xylem fluid of DP23211 corn has not been quantified. In the event IPD072Aa were to occur in 

phloem sap or xylem fluid, a general estimate of potential exposure is provided below. Because there is 

no quantitative data on the individual protein content of corn phloem sap or xylem fluid, a putative 

IPD072Aa protein concentration in phloem sap and xylem fluid can only be roughly estimated based on 

the concentrations of other proteins identified in the phloem and xylem of other plants. 

Phloem sap proteomes have been analyzed in rice, melon, cucumber, pumpkin, pumpkin, canola, and 

castor bean plant. Proteins serving various functions have been observed to include plant defense, signal 

transduction, RNA trafficking, In general, the phloem sap in most plant species studied have total protein 

concentrations in the range of 0.1–2.0 μg/μl (Schobert et al. 1998; Thompson and Schulz 1999; Dinant et 

al. 2010). However, cucurbits are known to have significantly higher protein concentrations in phloem 

sap, up to 60 μg/μl in cucumber and 35 μg/μl in pumpkin. Most proteins identified range in size from 5 to 
4-52

100 kDa. Individual plant species appear to exhibit a characteristic set of soluble proteins within their 

sieve-tube exudate, with total protein concentrations of 0.1 μg/μl for wheat (Triticum aestivum), 0.2 μg/μl 

for Asian rice (Oryza sativa), 0.1 -0.3 μg/μl for linden tree (Tilia platyphyllos), 0.2 -0.4 μg/μl for black 

locust (Robinia pseudoacacia), 0.2 - 0.5 μg/μl for castor bean plant (Ricinus communis), 0.5 - 1.0 μg/μl 

for yucca (Yucca filamentosa), and 19 – 30 μg/μl for winter squash (Cucurbita maxima) (Schobert et al. 

1998). Studies have established that there is a set of constitutive proteins present in the sieve-tube system 

of monocot and dicot plants, which likely reflects some basic function in the highly specialized phloem 

long-distance transport system. In addition, for certain sieve-tube exudate proteins, there is wide speciesto species variation in the respective abundance of individual proteins. Furthermore, some phloem sap 

proteins appear to be species specific (Schobert et al. 1998).

Up to 200 soluble polypeptides with a wide range of molecular masses and isoelectric points have been 

identified in the plant species studied (Thompson and Schulz 1999; Dinant et al. 2010). The number of 

proteins identified in phloem vary widely across species, from 140 in canola, over 300 in Cucurbita 

maxima (winter squash), and 107 in Oryza sativa (Asian rice), with other studies identifying 50 or fewer 

proteins in Cucumis species (melon), Lupinus species (flowering plants), and Ricinis communis (castor 

bean plant) (Carella et al. 2016). In tomato, (Ogden et al. 2020) observed 169 proteins whose abundance 

changed significantly within the phloem sap, either during drought or recovery from drought. Proteomics 

analyses of xylem sap collected during host interactions with Fusarium oxysporum, a plant pathogen, 

were performed using tomato and Brassica oleracea (Gawehns et al. 2015; Pu et al. 2016). Both studies 

identified substantially more total proteins (∼150–285) with a relatively high proportion of those proteins 

showing differential abundance during infection. 

In summary, most plants exhibit total protein in phloem around 0.1–2 μg/μL, while the phloem sap of 

cucurbits contains around 10–60 μg/μL. Studies on Cucurbita maxima have identified from 11 to 320 

proteins in phloem sap (Carella et al. 2016). Based on available data, this would yield individual protein 

concentrations ranging from 30 ng/μL to 900 ng/μL. Cucurbit phloem sap-purified phloem protein II 

(PP2) has been found at a concentration of between 25 and 40 ng/μl (Balachandran et al. 1997). In 

Cucurbita maxima proteins in the 10 – 20 kDA range were found at a total concentration of 50 ng/μl, and 

in the 50 – 80 kDA range at a total concentration of 25 ng/μl; the number of individual proteins in these 

mass ranges, and their respective concentrations, was not quantified (Balachandran et al. 1997). For castor 

bean plant (Ricinus communis) individual protein concentrations in phloem sap, based on the data 

reviewed, would range from 10 - 20 ng/μl.

The extracted xylem fluid of corn has been shown to have a total protein concentration of 12 μg/mL 

(Alvarez et al. 2006). This concentration is comparable with xylem sap extracted from squash roots which 

contained 19 μg/mL total protein. A total of 154 proteins were identified in corn xylem fluid, although 

many were observed to have had the same molecular weight with a variable isoelectric point, indicating 

the presence of multiple forms of a protein (Alvarez et al. 2006). Among this total, 54 proteins were 

considered unique (Alvarez et al. 2006). Average protein concentration in the xylem fluid, for individual 

proteins, would be around 0.2 μg/mL (0.2 ng/μl). The proteins in the xylem fluid belong to three major 

categories: cell wall metabolism (58%), plant defense (26%), and proteins involved in proteolysis and 

peptidolysis (11%) (Alvarez et al. 2006). 
4-53

Corn phloem sap composition has been analyzed in only a limited number of studies. The specific protein 

content of corn phloem sap has not been studied, to date. Profiling of corn phloem sap exudates identified 

45 compounds including carbohydrates, amino acids, organic acids and a number of less abundant 

molecules such as sterols, vitamins, and polyamines (Yesbergenova et al. 2016). Potassium, chloride, and 

sucrose were the primary phloem sap constituents in corn, comprising 21%, 11.6%, and 38.3% 

respectively (Yesbergenova et al. 2016). Soluble sugars represent on average around 88% of the overall 

metabolite content of the phloem sap exudates. Sucrose was the most abundant carbohydrate, representing 

up to 76% (mean value) of the soluble sugars, depending on the line examined (Yesbergenova et al. 

2016). Amino acids have been found to comprise 5% to 16%, and nucleotides 0.2% (Ohshima et al. 1990; 

Yesbergenova et al. 2016). Over 40% of the nucleotide pool has been found be comprised of ATP. ATP, 

ADP and AMP can comprise up to 80% of the total pool of nucleotides (Ohshima et al. 1990). Other 

compounds such as myo-inositol, putrescine, and ethanolamine, were also identified, although they 

represented less than 2% of the total (Yesbergenova et al. 2016). Smaller amounts of arginine, asparagine, 

alpha-aminobutyrate (GABA), glycine, histidine, isoleucine, lysine, phenylalanine, proline, threonine, 

tyrosine, and valine were also detected in the phloem exudates (Yesbergenova et al. 2016). The 

concentration of these compounds in corn phloem sap was not analyzed. 

Douglas (2006) estimated that larvae of Acyrthosiphon pisum (pea aphid) ingested, on average, 1.92 μL 

phloem sap over 2 d (from days 6 to 8 after birth), during which time they increase in weight from 0.7 mg 

to 1.32 mg, equivalent to protein growth of 31 μg (31,000 ng). Assuming IPD072Aa protein could occur 

in the phloem sap in the range of protein concentrations found in other plants, summarized above, at 

around 30 ng/μL (ppm), pea aphid larvae of would intake 28 ng/day IPD072Aa protein. How much of this 

putative intake would be excreted or otherwise transformed via digestion is unknown. Adverse effects via 

direct consumption in diet studies on Coccinellidae were observed at 500 ng/mg (ppm) diet and higher

(Table 4-16).

Potential exposure of Coccinellidae to any IPD072Aa via sap would likely be below an effects level of 

100 ng/mg diet; consequently, it is unlikely that any IPD072Aa present in DP23211 corn phloem sap and 

xylem fluid presents a hazard to Coccinellidae that may feed on aphids or other species of sucking insects 

that have ingested DP23211 corn phloem or xylem fluids. 

Based on the leaf, grain, and pollen expression levels of IPD072Aa, specificity for western corn rootworm 

with an LC50 of 26 ng/mg diet; absence of adverse effects on honeybee larvae at 200 ng/larva and adults 

1300 ng/bee/day; absence of adverse effects on most NTOs studied at dietary concentrations below 100 

ng/mg diet, and limited effects on coccinellids at 100 ng/mg diet or higher, dietary concentrations that 

would not be achieved in the field; the IPD072Aa protein in DP23211 corn is not expected to present a

any hazard to NTO populations, to include coccinellids.

Aquatic Invertebrates

As previously discussed, the DvSSJ1 dsRNA nucleotide sequence is specific for smooth septate junction

protein (DvSSJ1) mRNA in mid-gut epithelial cells of western corn rootworm (Diabrotica virgifera 

vergifera; Coleoptera), with no activity observed in other orders. The IPD072Aa proteins has targeted

activity in Coleoptera. Hence, it is unlikely DvSSJ1 dsRNA and the IPD072Aa protein would have 
4-54

biological activity in aquatic invertebrate species (e.g., among the orders Plecoptera, Megaloptera, 

Diptera, Anostraca). Nevertheless, an overview of potential exposure is provided. 

The worst-case EEC for aquatic organisms to DvSSJ1 dsRNA and the IPD072Aa protein in DP23211 

corn tissues was estimated using the EPA standard agricultural field-farm pond model (also called the 

U.S. EPA standard pond model). Based on the assumptions in the EPA farm pond model, the worst-case 

EECs for aquatic organisms are 2.46 x 10-4 mg/L and 0.124 mg/L (ppm) for the DvSSJ1 dsRNA and the 

IPD072Aa protein, respectively. The LC50 of DvSSJ1 dsRNA for western corn rootworm is 0.036 ng/mg

(ppm), which is 146X higher than the worst-case EEC for aquatic organisms. The LC50 of the IPD072Aa

protein for WCR is 26 ng/mg (ppm), which is 210X higher than the worst-case EEC for aquatic 

organisms (Pioneer 2020). 

Several factors would limit aquatic exposures to DP23211 corn plant material. It would generally take a 

very heavy rain event to transport corn plant material to nearby water bodies (i.e., a fallen leaf or kernel). 

Topsoil would be more readily transported. DvSSJ1 dsRNA and IPD072Aa would not be expected to 

commonly occur in soils; only as a matter of degradation of plant material that was left on the field postharvest, plant material that may have fallen to the ground as a result of animals foraging on the crop, plant 

material that may have fallen to the ground during drying for silage—or decaying root material. As 

previously discussed for potential impacts on soil biota, environmental DNA/RNA is generally degraded

within a week, most studies stating two or three days (Dubelman et al. 2014; Parker et al. 2019). The 

IPD072Aa protein is fully degraded after about a week (Pioneer 2020). Albright et al. (2017) examined 

dissipation of a 100 base pair dsRNA in three different microcosms (laboratory water over sterilized 

sediment, sterilized pond water over sterilized sediment, and active pond water over active sediment). 

This study concluded that the dsRNA degraded rapidly within all three microcosms and was undetectable 

by 96 hrs. Degradation kinetics estimated a half-life of less than 3 days and a time to 90% dissipation of 

approximately 4 days. Studies by Fischer et al. (2017) found DvSnf7 RNA to fully degrade in surface 

waters within 4 to 6 days. There is no data on the degradation rate of IPD072Aa in water.

Considering the slow rate of plant tissue decay, amount of dsRNA and IPD072Aa that would be deposited 

in soils, and residence times of dsRNA and IPD072Aa in soils, it is unlikely that intact dsRNA or 

IPD072Aa of sufficient quantity to elicit biological activity would enter surface waters via topsoil runoff. 

Hence, the risk of exposure of aquatic invertebrates to DvSSJ1 dsRNA or IPD072Aa via com detritus is 

expected to be negligible. While some exposure to DvSSJ1 dsRNA may conceptually occur in the water 

column, it would likely be short lived. 

Based on these factors, the buildup of post-harvest plant debris or topsoil comprised of DvSSJ1 dsRNA

and IPD072Aa protein in surface waters, particularly those waters with continual movement, is expected 

to be of negligible quantity and limited in occurrence. 

Synthetic Chemical Insecticides: Invertebrates and Aquatic Biota

To some extent, there could be less reliance on use of insecticides with DP23211 corn to control WCR.

As an IR corn variety comprised of PIPs (DvSSJ1 dsRNA and IPD072Aa protein) with specify for WCR, 

cultivation of DP23211 corn would likely entail less use of soil- and foliar-applied insecticides to control 

WCR. Adopters of transgenic PIP based IR corn have been found to use around 11.2% (0.005 kg/acre) 

less insecticide than nonadopters (Perry et al. 2016). These types of IR crops have also been found to 
4-55

facilitate reductions in use of insecticides in nearby non-IR grain and vegetable crops, owing to the areawide suppression of insect populations targeted by the PIP. For example, Dively et al. (2018) found that 

insecticides (total active ingredient) applied in non-IR sweet corn declined from 1.1 kg/acre (2.64 kg/ha) 

in 1992 to 0.23 kg/acre (0.55 kg/ha) in 2016, a 79% decrease. In pepper crops, insecticides applied 

declined from 2.05 kg/acre (4.92 kg/ha) in 1992 to 0.31 kg/acre (0.75 kg/ha) in 2016, an 85% decrease. 

Insecticide usage in peppers significantly declined as a function of proximity of Bt corn, while in sweet 

corn, the negative association was marginally significant. These results indicate that a significant 

proportion of the decreased insecticide usage in Mid-Atlantic vegetable crops could be attributed to the 

regional pest suppression associated with widespread Bt field corn adoption (Dively et al. 2018).

Certain insecticides can be toxic to invertebrates and fish at relatively low concentrations. Thus, any 

reductions in insecticide use, or limitation of insecticide use, would be environmentally beneficial. The 

four main agricultural insecticides used are pyrethroids (PYs), organophosphates (OPs), carbamates 

(CBs), and biological insecticides (BIs) (Helfric 2013; US-EPA 2019f). Among these, PYs, OPs, and 

CBs are used for CRW control at planting and post-planting (Wright 2009). 

PYs can be toxic to fish and aquatic invertebrates and use in proximity to waterways is cautioned (USEPA 2016d). EPA risk assessments for freshwater, estuarine, and marine vertebrate and invertebrate

species indicate pyrethroids can be highly toxic to aquatic organisms on an acute basis (US-EPA 2016d). 

Chronic effects are also seen in aquatic taxa. LC50 values for aquatic biota are in the parts per billion 

(ppb) and parts per trillion (ppt) range; thus, highly toxic (US-EPA 2016d).

Many OP and CB insecticides are also highly toxic to fish and wildlife. Fish kills involving these 

insecticides have been documented (US-EPA 2016d). OP insecticides can bioconcentrate in fish, frogs, 

tadpoles, and toads to levels that pose hazards to their predators (Hall and Kolbe 1980; Helfric). U.S. 

Geological Survey (USGS) studies found OP insecticides to be major contributors to toxicity in over half 

of the streams studied (Nowell et al. 2018). The CB insecticide carbofuran— used to control insects in a 

wide variety of field crops, including potatoes, corn, and soybeans—is highly toxic to wildlife and fish 

(Struger et al. 2016).

While the use of IR crops typically limits the use of broad-spectrum chemical insecticides (foliar sprays 

and soil insecticides), it is noted, however, that this benefit can to some extent be countered by the use of 

insecticidal seed treatments (to both IR and non-IR crop seed) for the management of early season pests,

and as insurance against sporadic soil-borne pests (Allen et al. 2018; Sappington et al. 2018). For 

example, neonicotinoids, which are used on more than 90% of corn acres (USGS 2020a), can persist in 

the environment, accumulate in soils, enter waterways via runoff, and can pose a threat to a number of 

non-target species, especially bees and other pollinators, and soil and aquatic invertebrates (Perry and 

Moschini 2020; Schulz et al. 2021). Neonicotinoid use for seed treatment is related to their toxicity in

broad array of insect species, and simultaneously low acute toxicity to mammals (Douglas and Tooker 

2016). Pyrethroids are effective in controlling a broad range of insect pests, although are toxic to aquatic 

organisms (US-EPA 2016d). While this point is noted, use of neonicotinoid seed treatment, which may be 

applied to conventional and biotechnology based seeds, is unrelated to the introduced IR traits in 

DP23211 corn. 

Summary 
4-56

The DvSSJ1 dsRNA has been shown to have a narrow spectrum of activity, primarily affecting corn 

rootworm (Diabrotica; Coleoptera) (Boeckman et al. 2019; Hu et al. 2019). The IPD072Aa protein 

likewise has specific activity targeting western corn rootworm. The tissue expression levels of both in 

DP23211 corn are expected to effect western corn rootworm populations, with negligible effects on 

nontarget species. 

No synergism among DvSSJ1 dsRNA and IPD072Aa has been observed, nor it is expected: Based on the 

separate mechanisms of action for IPD072Aa protein and DvSSJ1 dsRNA, it is unlikely that DvSSJ1 

dsRNA and IPD072Aa can combine to elicit an increased synergistic effect on insects that ingest 

DP23211 corn (Pioneer 2020). IPD072Aa protein binds to brush border membrane receptors in the 

western corn rootworm gut causing disruption of the mid-gut epithelium function. The DvSSJ1 dsRNA 

acts to inhibit translation of the target mRNA, which, as a result, diminishes the level of an essential 

protein needed for the formation/maintenance of smooth septate junctions in WCR (Pioneer 2020). 

Due to the species specificity of the insecticidal traits, and to some extent reduction/limitation in the use 

of synthetic chemical insecticides with DP23211 corn, as well as possible contribution to 

reductions/limitations in insecticide use in nearby corn crops owing to area-wide suppression of 

Diabrotica virgifera virgifera, DP23211 corn production would be expected to present fewer hazards to

non-target insect populations, as compared to broad spectrum chemical insecticides. As discussed in 

Section 4.3.1.2.2–Agronomic Inputs, over the top insecticide use in corn production has significantly 

declined during the last 20 years due in part to the adoption of IR corn varieties. The use rate of 

insecticides applied to corn fell from an average of around 0.08 kg/acre in 1998 to about 0.02 kg/acre in 

2011 (a 75% decrease), as the adoption of IR corn crops increased (Perry et al. 2016). In general, adopters 

of IR corn use around 11.2% less insecticide than nonadopters (Perry et al. 2016). Limits on chemical 

insecticide use with IR corn, and possible contributions to reductions in insecticide use in nearby

cropping systems, is of environmental benefit to both terrestrial and aquatic biota. In this respect, 

production of IR crops, to include DP23211 corn, has the potential to be more environmentally benign—

have less of an effect on non-target pest populations—as compared to conventional synthetic chemicalbased pest management approaches. 

Overall, studies to date have shown that the effects of IR crops on non-target populations are minimal to

negligible in comparison to the effects of broad-spectrum chemical insecticides (e.g., see review by (NAS 

2016; Romeis et al. 2019)). Because DP23211 corn crops would have more targeted control of a specific 

species of plant pest (Diabrotica virgifera virgifera) with less reliance on broad-spectrum synthetic 

chemistries, this could, in a comparative sense, be favorable to sustaining beneficial insect activity, and 

reduce the adverse effects of synthetic chemical insecticides on non-target insect populations (Gatehouse 

et al. 2011; Dively et al. 2018; Romeis et al. 2019).

Lastly, transgenic corn hybrids expressing Cry3Bb1, mCry3A, eCry3.1Ab as well as Cry34/35Ab1 were

introduced into the market to manage WCR. Development of resistance in some WCR populations to 

Cry3 based PIPs has constrained the options for management of WCR (Zhao et al. 2019), ultimately 

resulting in greater reliance on broad-spectrum chemical insecticides to control resistant pest populations.

Because the modes of action of both DvSSJ1 dsRNA and IPD072Aa MOAs differ from the Cry3A, 

Cry3Bb1, Cry 34/35Ab1, Cry3.1Ab toxins, this corn variety, to the extent grown, could help alleviate 
4-57

selection pressure for Cry resistant WCR populations, and thereby the potential for increased insecticide 

use to control Cry resistant WCR populations. 

4.3.3.3 Plant Communities

Plant diversity in areas surrounding crop fields is an important component of a sustainable agricultural 

system (Scherr and McNeely 2008; CBD 2020b). Hedgerows, woodlands, and fields provide not only 

wildlife habitat but serve as important reservoirs for beneficial insects (although plant pests as well). By 

providing habitat, pollen and nectar resources, and serving as hosts, plants adjacent to corn fields can 

support a suite of beneficial arthropod species that serve as pollinators of insect-pollinated crops, and 

biological control agents—insects that prey on corn plant pests, such as lady beetles, spiders, and parasitic 

wasps (Scherr and McNeely 2008; Nichols and Altieri 2012). However, for corn production, pollinators 

would not be as valued from an agronomic perspective, as corn is primarily wind pollinated. Surrounding 

plant communities can also help regulate run-off, reduce soil erosion, and improve water quality. Hence, 

sustaining surrounding plant communities can provide benefits to corn crop production via control of 

insect pests and agricultural run-off (Altieri and Letourneau 1982), and provide pollinator services to 

other plants that benefit from insect pollination (Nichols and Altieri 2012). 

Members of plant communities in and around cornfields that adversely affect corn cultivation are 

generally characterized as weeds, and the presence of these plants controlled to maximize crop yield and 

quality (Section 4.3.1.2.2.3). Most relevant to environmental review of transgenic cropping systems are 

those sexually compatible plant communities with which the transgenic crop plant can interbreed

(discussed following in Section 4.3.3.4).

4.3.3.3.1 Potential Effects on Plant Communities

Cultivation of DP23211 corn would be expected to have similar impacts on vegetation proximate to 

DP23211 corn fields as currently cultivated corn varieties, relative to the particular herbicides used. When 

crops are sprayed, sublethal doses of herbicides may reach non-target plant species in adjacent habitats 

through drift, runoff, and/or volatilization. Sublethal effects on sensitive species could include negative 

impacts on leaves (photosynthesis), seed production, delays in flowering times, and reductions in flower 

production. Reviews of this topic suggest that after application typically less than 1% of herbicide 

applied is lost to groundwater leaching, approximately 1%–4% is carried away in surface runoff, with 

losses via drift and volatilization ranging between 5%–25% (Boutin et al. 2014; Prueger et al. 2017).

Glufosinate is a broad spectrum herbicide that affects monocotyledonous (monocot) and dicotyledonous 

(dicot) species. Glufosinate spray drift may inadvertently impact non-target plants proximate to DP23211 

corn fields. Consequently, glufosinate herbicides must be used in accordance with the spray drift 

management precautions on the EPA label to minimize off-site exposures (US-EPA 2020e). Herbicides 

that contain glufosinate are often applied with a boom-mounted sprayer. However, they can be 

occasionally applied aerially on corn, cotton, potato, and soybean. Generally, less than 1% of the total 

amount of glufosinate-containing herbicides were applied from the air, with the largest part on potatoes 

(22% of potato crops are treated with glufosinate by air) (US-EPA 2016e). The EPA provides guidance 

and label use requirements for reducing the probability of herbicide spray drift and volatilization (USEPA 2019c, j).
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4.3.3.4 Gene Flow and Weediness of Corn

Gene flow among transgenic crops and conventional and organic cropping systems, as wells as other 

transgenic crops, is of particular interest to farmers, and federal and state regulators, as such gene flow 

can adversely affect farmers’ net returns on crops, and domestic and international trade.14 Gene flow from 

transgenic plants to sexually compatible wild relative species is a topic of interest among ecologists and 

environmentalists, as well as federal and state regulators, due to concerns that a transgene may confer 

weediness traits to, or alter the fitness of, wild relative species. 

Of interest to APHIS is the possible occurrence of gene flow from a transgenic plant to sexually 

compatible wild relative species that could lead to introgression of the trait gene into a wild population, 

and development of a phenotype that could adversely affect agricultural interests and/or the environment. 

4.3.3.4.1 Factors Governing Gene Flow among Crop Plants and Wild Relative Species

The rate and success of pollen mediated flow is dependent on numerous factors such as the presence, 

abundance, and distance of sexually-compatible plant species; overlap of flowering times among 

populations; method of pollination; biology and amount of pollen produced; and weather conditions, 

including temperature, wind, and humidity. 

The salient environmental concern is whether the flow of a transgenic trait gene (i.e., herbicide resistance, 

insect resistance) to a wild relative will have adverse ecological consequences. For a significant 

environmental impact to occur, gene flow would have to lead to the production of a fertile hybrid plant 

that produces viable offspring, and the resulting transgenic–wild plant hybrid having some type of 

competitive advantage that can lead, ultimately, to introgression of the transgene into a wild plant 

population. Gene flow itself does not necessitate the increased fitness of a hybrid. The transgene in a wild 

relative or other crop plant may very well prove detrimental to the hybrid, or have no effect (Ellstrand et 

al. 2007; Ellstrand 2014; Goldstein 2014). The ecological consequences of a transgene in a wild species 

depends on the type of trait, the stability of the gene in the genome, the fitness conferred to the hybrid 

through expression of the trait gene, and ecological factors in the area of the hybrid (Felber et al. 2007; 

Ellstrand 2014). 

It is generally assumed that traits that impart increased fitness or are neutral will persist in populations 

and those that impart negative effects on plant fitness will not. If a resulting transgenic-wild type hybrid 

had a competitive advantage over wild populations, it could persist in the environment and potentially 

disrupt the local ecology. Where the transgenic trait does not provide fitness, and is not deleterious to 

survival of the hybrid, the transgene may still persist in wild populations with no effects on the local 

ecology. 

In respect to the occurrence of a transgenic-wild type hybrid, gene flow from a transgenic crop plant to 

wild or weedy relative species does not necessarily constitute an environmental harm in and of itself, nor 

does it inherently imply environmental damage. The salient issue is what the resultant ecological 

consequences of such gene flow to a wild population may be (Ellstrand 2014). Current understanding 

14 The term “gene flow” can be synonymous with “outcrossing” and the terms are used here interchangeably. Neither term 

implies the long-term persistence or introgression of gene(s) into a recipient population. A hybrid is the offspring of two 

genetically dissimilar but sexually compatible species, generally within the same genus, although hybrids between different 

genera are possible.
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suggests that the presence of a transgenic trait outside the area of cultivation will likely have little or no 

adverse consequences unless: 

(1) the trait confers novel or enhanced fitness or weediness to the wild relative hybrid, resulting in 

the evolution of increased weediness or invasiveness in wild type hybrids, or

(2) the trait confers to transgenic-wild relative hybrid progeny reduced fitness, resulting in a selective 

disadvantage in wild relative populations (Ellstrand 2014). 

Hence, in evaluating potential environmental impacts it is not the risk of gene flow itself that is the chief 

concern, but rather the environmental consequences that could occur as the result of such an event; 

whether the transgene will persist in a wild population, and whether hybrid or introgressed populations 

will have adverse ecological consequences. 

4.3.3.4.2 Gene Flow among Corn (Zea mays L.) and Wild Relative Species

Corn (Zea mays L. subsp. mays) is one of the oldest domesticated food plants in the world, the origins of 

which date back to around 5,000 – 3,600 years ago in southern Mexico (de Wet et al. 1978; Eubanks 

1995). How corn evolved is still a matter of investigation, although most investigators agree that what we 

know as cultivated corn most likely descended from an annual species of “teosinte” (Zea mays ssp. 

parviglumis), a closely related wild grass endemic to Mexico (Wilkes 1967; Iltis and Doebley 1980; 

Piperno and Flannery 2001). Teosinte is the common name applied to several distinct wild Zea species 

closely related to corn (Zea mays L. ssp. mays). Cultivated corn (Zea mays L. subsp. mays) is sexually 

compatible with teosinte (Zea spp.), with a few exceptions. The closest relative of Zea in the United 

States is among the genus Tripsacum, with which corn does not readily hybridize (discussed further 

below). 

Teosinte

Wild teosinte relatives of corn comprise a group of annual and perennial species that commonly occur 

within the tropical and subtropical areas of Mexico, Guatemala, Costa Rica, Honduras, El Salvador, and 

Nicaragua (Sánchez González et al. 2018). The natural geographic distribution of teosinte extends from 

the Western Sierra Madre of the State of Chihuahua, Mexico, to the Pacific coast of Nicaragua and Costa 

Rica, including the western part of Mesoamerica. The Mexican annuals Zea mays ssp. parviglumis and 

Zea mays ssp. mexicana show a wide distribution in Mexico, while Zea diploperennis, Zea luxurians, Zea 

perennis, Zea mays ssp. huehuetenangensis, Zea vespertilio and Zea nicaraguensis have more restricted 

and distinct ranges, representing less than 20% of the total occurrences from published sources for the 

period 1842-2016 (Sánchez González et al. 2018). 

Except for Z. perennis, Zea mays and teosinte cross readily, and their hybrids are fully fertile (de Wet and 

Harlan 1972). Hybridization and introgression between Z. mays and the subspecies Z. mays subsp. 

mexicana occurs in Mexico, and has probably been taking place since the advent of corn domestication 

wherever these two taxa are sympatric (de Wet et al. 1978; Ellstrand et al. 2007). In general, humans 

breed in the direction of corn (Zea mays), and nature strongly favors teosinte over their hybrid, which is 

less well adapted for natural seed dispersal (de Wet and Harlan 1972). The rate at which domesticated 

corn crop genes may enter teosinte populations will be limited by genetic barriers, phenological 

differences, and the relative fitness of the hybrids (Ellstrand et al. 2007). 
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Teosinte do not appear to be present in the United States other than in botanical gardens or at research 

stations. The USDA Plants Database lists Zea mexicana (Syn. Z. mays ssp. mexicana) as present in 

Florida, Alabama, and Maryland, having been introduced from Mexico (USDA-NRCS 2019d). Teosinte 

has, apparently, occasionally been cultivated in the Southern United States for forage (Hitchcock 1951). 

The documentation cited for occurrence in Florida only shows distribution of native or naturalized 

populations in Miami-Dade, Orange, and Levy Counties (Wunderlin et al. 2019). While citations were 

provided in the Plants database for distribution in Maryland and Alabama, current Maryland plants 

databases have no listed Zea species, other than Z. mays (UMD 2005; MPAWG 2016), nor are any Zea

species or subspecies other than Z. mays (corn) listed in Alabama (Kral et al. 2019).

Zea perennis (Syn. Euchlaena perennis Hitchc.) is listed as occurring in Texas and South Carolina. It is 

described as having been cultivated at academic research stations in Texas, and established on James 

Island, South Carolina (Hitchcock 1951). It is not known if the James Island population has persisted. 

There are no Zea species found in the comprehensive online South Carolina Plant Atlas (USC 2020); 

which catalogues over 3000 species.

Teosinte identified as Zea mays ssp. parviglumis is listed as having occurred in Miami-Dade County, 

Florida (Wunderlin et al. 2019), an area that is now largely urban. Zea diploperennis and Zea luxurians

are also listed in the USDA Plants database, but there is no information about the presence of any wild 

populations in the United States. 

Experts familiar with the teosinte collections in the United States, some of whom were involved with 

revision of the Manual of Grasses for North America (Roché et al. 2007), are not aware of any naturalized 

or native populations of teosinte currently growing in the United States (USDA-APHIS 2013).

Tripsacum 

The closest relative of Zea in the United States is the genus Tripsacum (OECD 2003). Three species of 

Tripsacum have been identified in the United States: T. dactyloides, Eastern gamagrass, is known to occur 

in the eastern half of the United States, T. lanceolatum, Mexican gamagrass, occurs in the southwest of 

the United States, and T. floridanum, Florida gamagrass, is native to South Florida and Cuba (OECD 

2003; USDA-NRCS 2019b). T. dactyloides is the only Tripsacum species of widespread occurrence and 

agricultural importance in the United States, and commonly is grown as a forage grass (USDA-NRCS 

1996). T. fasciculatum and T. latifolium occur in Puerto Rico (USDA-NRCS 2019b). Tripsacum species 

(2n=18) can be represented by diploid, triploid, tetraploid, and higher ploidy levels (Lee et al. 2017). 

Hybrid combinations with Z. mays (as pollen donor) and T. dactyloides are known to give rise to 

recovered Z. mays within three or more further backcrosses with Z. mays. It is, however, not too likely 

that this process commonly occurs in nature (de Wet et al. 1978). With each successive backcross, the 

offspring become more Z. mays like, and less capable of surviving in competition without the help of 

humans. Hybrids have been observed to not only produce low yields, but are also partially female sterile 

(de Wet et al. 1978).

In summary, gene exchange is possible between Zea and Tripsacum, and several South American races of 

corn exhibit past evidence of hybridization (de Wet et al. 1978). Natural introgression between Zea and 

Tripsacum, however, appears unlikely (de Wet et al. 1978). Hybrids between Z. mays and Tripsacum, as 
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well as their derivatives when backcrossed with Z. mays, are poorly adapted for survival in competition 

with both their wild and cultivated parents (de Wet et al. 1978). Although hybridization of Tripsacum and 

Z. mays has been accomplished in the laboratory using special techniques under highly controlled 

conditions (Wozniak 2002; Lee et al. 2017), pollen-directed gene flow from corn (Zea mays) to wild 

Tripsacum species is considered an unlikely event (Wozniak 2002; Lee et al. 2017). APHIS is unaware 

of any reported cases of hybridization among naturally occurring Tripsacum and Z. mays in the United 

States.

4.3.3.4.3 Corn as a Weed or Volunteer 

In the United States, there are no Zea species listed on the Federal Noxious Weed List (7 CFR part 360) 

(USDA-NRCS 2019b). Corn (Zea mays), as a highly domesticated crop plant with limited seed dispersal 

and dormancy, does not readily form persistent feral populations; does not present as a weed outside of 

areas of cultivation (USDA-NRCS 2019d; USDA-APHIS 2022b). 

Corn can and periodically does occur as a volunteer plant in subsequent crops planted in the same field. 

Corn seed can remain in fields as a result of harvester inefficiency, dispersal by birds and other foraging 

wildlife, or from fallen ears. When seeds survive to the next growing season, volunteer plants may 

develop within subsequent crops rotated with corn, such as soybean, dry beans, sugar beets, as well as 

subsequent corn crops. 

Volunteer corn is more of agronomic/economic than environmental concern; the presence of volunteers 

can result in minor to significant yield impacts on subsequent crops planted in the same field, depending 

on the density of the volunteer corn (Nicolai et al. 2018; Jhala et al. 2019). In controlled agronomic 

studies, volunteer corn densities ranging from 800 to 13,000 plants per acre resulted in yield losses of 0 to 

54% in soybean and 0 to 13% in corn (Nicolai et al. 2018). Similarly, soybean yield reductions have been 

found to range from 10 to 41% where early-emerging volunteer corn densities ranged from 0.5 to 16 

plants m2

, although no soybean yield loss occurred with a late-emerging cohort of volunteer corn 

(Marquardt et al. 2012). Successful control of volunteer corn is accomplished with the use of various 

combinations of cultivation practices and use of herbicides with differing modes of action (Jeschke and 

Doerge 2010; Nicolai et al. 2018). 

4.3.3.4.4 Probability and Potential Effects of Gene Flow

DP23211 corn, if grown for commercial purposes, would be cultivated as are current corn varieties and 

present the same potential risk for gene flow, specifically the propensity for and frequency of gene flow, 

as current corn varieties. As APHIS concluded in its PPRA, the introduced trait genes in DP23211 corn 

are not expected to alter characteristics associated with reproductive biology—change the ability of the 

plant to interbreed with other plant species (USDA-APHIS 2022b). Accordingly, a determination of

nonregulated status for DP23211 corn and subsequent commercial production would not be expected to 

present more or less risk for gene flow to wild relative species, or other corn crops, as do current corn

varieties.

As previously reviewed, teosinte (Zea spp.) do not appear to be present in the United States other than in 

botanical gardens or at research stations. Thus, there is no plausible opportunity for interbreeding. Three 

species of Tripsacum have been identified in the United States: Eastern gamagrass, Mexican gamagrass, 

and Florida gamagrass. Eastern gamagrass is the only Tripsacum species of widespread occurrence
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(USDA-NRCS 2002). Conceptually, the IR trait could confer a competitive advantage to wild Tripsacum 

species. The pat transgene would confer resistance to glufosinate-ammonium. In the event gene flow from 

DP23211 corn to Tripsacum species occurred, the HR trait would not be expected to confer any fitness 

advantage, or disadvantage, in areas where glufosinate was not regularly used. While conceptually 

possible, the likelihood of Tripsacum populations harboring the IR and HR trait genes is considered 

remote. First, in contrast with corn and teosinte (Zea spp.), which may hybridize relatively easily under 

certain conditions, the potential for hybridization and successful introgression of Z. mays genes into 

Tripsacum populations is rare (de Wet and Harlan 1972; de Wet et al. 1978; Eubanks 1995). Special 

techniques are required to hybridize Z. mays and Tripsacum; hybrids of Tripsacum species with Zea

species do not commonly occur outside of a laboratory. Offspring are often sterile or have reduced 

fertility, and are unable to withstand even mild winter conditions (de Wet and Harlan 1972; de Wet et al. 

1978; Eubanks 1995). 

Second, while corn pollen can travel as far as 1⁄2 mile (800 m) in 2 minutes in a wind of 15 miles per hour 

(27 km/h) (Nielsen 2016), most pollen is deposited within a short distance of the corn plant. Numerous 

studies show the majority (84-92%) of pollen grains travel less than 16 feet (5 meters) (Pleasants et al. 

2001). At a distance of 200 feet (60 m) from the corn plant, the pollen concentration averages only about 

1%, compared with pollen samples collected about 3 feet (0.9 m) from the pollen source (Burris 2002; 

Brittan 2006). In terms of pollination: The number of potential outcrosses is reduced to one-half at a 

distance of 12 feet (3.6 m) from the pollen source, and at a distance of 40 to 50 feet (12 to 15 m), the 

number of outcrosses is reduced by 99%. Thomison ( 2004) showed cross-pollination between cornfields 

could be limited to 1% or less by a separation distance of 660 feet (200 m), and to 0.5% or less by a 

separation distance of 984 feet (300 m). However, cross-pollination frequencies could not be reduced to 

0.1% consistently, even with isolation distances of 1,640 feet (500 m). 

4.3.3.5 Biodiversity

Biological diversity in the context of agriculture means the variety of and interactions among the 

communities of animals, plants, and microorganisms that comprise the structure and functions of 

agroecosystem (FAO 1999). Agricultural biodiversity provides stability, adaptability, and resilience to 

cropping systems, and central to sustainable cropping systems and food security (FAO 2008; Mijatović et 

al. 2013).

Various taxa contribute to essential ecological functions upon which agriculture depends, such as 

pollinators, soil biota, and predators of crop pests (CBD 2020b). One invaluable function of sustaining 

diverse insect populations on farms is the natural control of plant pest populations via predation, 

parasitism, and feeding competition among herbivores. In one study of corn farms across the Northern 

Great Plains, Lundgren and Fergen (2014) found that farms with lower insect diversity had more plant 

pests, and that more bio-diverse cornfields had fewer plant pests. The results from their study show that 

designing cropping systems for high insect diversity— increasing vegetation diversity on farms by 

lengthening crop rotations, using cover crops in rotations, intercropping, managing field margins, and 

using minimal-till agriculture— can facilitate control of plant pests, requires fewer insecticide inputs, and 

can save farmers time and money. 

Relative to HR/IR crops, by facilitating conservation tillage, limiting insecticide use, and helping sustain 

maximum yield—which alleviates pressure to convert additional land into agricultural use—HR/IR crops 
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can contribute to reducing the impacts of agriculture on biodiversity (Carpenter 2011; Raman 2017). A 

U.S. National Research Council assessment of the relationship between crop production and farm 

sustainability in the United States concluded that, generally, HR and IR crops have had fewer adverse 

effects on the environment than crop varieties produced conventionally (NRC 2010). During the 1996 –

2016 timeframe the adoption of HR and IR technology reduced pesticide spraying in the United States by 

361 million kg (796 million pounds), and facilitated reductions in tillage and fossil fuel use (Brookes and 

Barfoot 2017).

Studies in sweet corn, which is routinely treated with foliar insecticides during production, have 

documented that the conservation of natural enemies of plant pests with Bt based crops can facilitate

biological control in cropping systems. Musser and Shelton (2003) found that Bt sweet corn (lepidopteran 

resistant) was less toxic to the major predators in the cropping system (ladybeetles C. maculata and H. 

axyridis and the minute pirate bug, Orius insidiosus), than the commonly used pyrethroid insecticide 

lambda cyhalothrin, and the insecticides spinosad and indoxacarb. This study demonstrated that Bt corn 

provided effective control of lepidopteran pests, and did not negatively affect the predation rates of egg 

masses of the European corn borer (a significant plant pest), as did lambda cyhalothrin and indoxacarb

(Musser and Shelton 2003; Romeis et al. 2019). A follow-up study proposed a model that integrates

biological and chemical control with transgenic IR crops for suppressing not only the target pests, but 

secondary pests such as aphids that affect marketability (Musser et al. 2006).

HR and IR crops have also made important contributions to increasing global production levels. As of 

2018, these traits have facilitated—since the introduction of the technology in the mid-1990s—the 

addition of 278 million metric tons and 498 million metric tons to the global production of soybeans and 

corn, respectively (Brookes and Barfoot 2018c). The average yield impact across the total area planted to 

HR and IR corn during the 1996 – 2018 timeframe has been +16.5% (Brookes and Barfoot 2018c). To 

maintain global production levels at 2018 levels, without crops with HR and IR traits, would have 

required farmers to plant an additional 4.9 million acres (12.3 million hectares) of soybeans, 3.3 million 

acres (8.1 million hectares) of corn, 1.25 million acres (3.1 million hectares) of cotton, and 0.2 million 

acres (0.7 million hectares) of canola, an area equivalent to the combined agricultural area of the 

Philippines and Vietnam (Brookes and Barfoot 2018c).

4.3.3.5.1 Potential Effects on Biodiversity

Commercial production of DP23211 corn would not be expected to affect biodiversity in and around 

DP23211 corn crops any differently than other corn cropping systems. As previously reviewed, the

DvSSJ1 dsRNA, and IPD072Aa, PAT, and PMI trait proteins are unlikely to present any hazards to plant, 

animal, fungal, or bacterial communities—apart from the intended impacts of the DvSSJ1 dsRNA and 

IPD072Aa traits on targeted Diabrotica virgifera virgifera. While there would be reductions in 

Diabrotica virgifera virgifera with perhaps some cascading effects on predator/parasitoid populations in 

terms of availability of prey species (Chaplin-Kramer et al. 2011; Letourneau et al. 2011; González et al. 

2016), this would not be expected to have a significant effect on insect populations and community 

dynamics within DP23211 corn crops, or areas adjacent to DP23211 corn crops (e.g., predators, 

pollinators) (Strand and Obrycki 1996; Obrycki et al. 2021). While some predatory species are highly 

specific and feed on only one species of prey, most others feed on either a limited range of related taxa

(are stenophagous or oligophagous), or a wide variety of prey (are polyphagous—general feeders).

Predators of Diabrotica virgifera virgifera include beetles (Carabidae, Staphylinidae, Dermestidae), mites 
4-64

(Hypoaspis aculeifer), ants (Lasius neoniger, Myrmica americana, Pheidole bicarinata), and spiders 

(Araneae) (Kuhlmann and Burgt 1998; CABI 2020), all of which also feed on range of other species 

(Adalbert et al. 2008; Carvalho et al. 2017; Gathalkar and Sen 2018; Raupp et al. 2021).

In general, IR crops such as DP23211 corn, for the most part, have the potential to be more 

environmentally benign than chemical insecticide-based pest management approaches (Gatehouse et al. 

2011; Romeis et al. 2019). While biodiversity will be inherently limited in commercial corn crops due to 

frequent disturbance of the landscape, tillage, mechanized planting, planting of a monoculture crop, and 

application of pesticides, HR/IR crops have generally reduced the environmental impacts of crop 

production, relative to conventional broad-spectrum chemical approaches to pest management (NRC 

2010; NAS 2016; Raman 2017; Brookes and Barfoot 2018a; Romeis et al. 2019). Glufosinate use for 

weed control would be subject to EPA label requirements, no different than for other corn crops.

Growers and federal and state agencies well recognize the need for maintenance of cropland biodiversity. 

A variety of federally supported programs, such as the USDA funded Sustainable Agriculture Research 

and Education Program (SARE), and partnership programs among the EPA and the agricultural 

community support agricultural practices that are intended to protect the environment, conserve natural 

resources, and promote cropland biodiversity (i.e., (US-EPA 2019i; USDA-NIFA 2020)). The USDA 

Natural Resources Conservation Service, through its Conservation Stewardship Program, Landscape 

Initiatives, Environmental Quality Incentives Program, Landscape Planning, and other services provides 

technical and financial support to growers to assist in managing the complex interaction of cropping 

systems and the natural environment (USDA-NRCS 2019a). Tools are also developed by the industry. 

For example, Field to Market: The Alliance for Sustainable Agriculture supports various programs that 

helps farmers and the food supply chain benchmark sustainability performance, to included biodiversity 

(Field-to-Market 2019).

4.3.3.6 Threatened and Endangered Species

Section 7(a)(2) of the ESA requires that federal agencies, in consultation with the U.S. Fish and Wildlife 

Services (USFWS) and/or the National Marine Fisheries Services (NMFS) ensure that any action they 

authorize, fund, or carry out is “not likely to jeopardize the continued existence of a listed species or 

result in the destruction or adverse modification of designated critical habitat.” It is the responsibility of 

the federal agency taking the action to assess the effects of their action on threatened and endangered 

species (TES) listed under the ESA, and to consult with the USFWS and NMFS if it is determined that 

the action “may affect” listed species or designated critical habitat (a process is known as a Section 7 

Consultation). 

4.3.3.6.1 Potential Effects on TES

After reviewing the possible effects of a determination of nonregulated status for DP23211 corn, 

discussed in Appendix 1, APHIS has not identified any stressor that could affect listed TES or species 

proposed for listing. APHIS also considered the potential effect of DP23211 corn on designated critical 

habitat and habitat proposed for designation, and could identify no differences from effects that would 

occur from the production of other corn varieties. Corn is not sexually compatible with, nor serves as a 

host species for, any listed species or species proposed for listing. A discussed previously in 4.3.3.2–

Animal Communities, consumption of DP23211 corn by any listed species or species proposed for listing 

would pose negligible physiological risks.
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Based on our evaluation provided in Appendix 1, APHIS has concluded that a determination of 

nonregulated status of DP23211 corn, and subsequent commercial production of this corn variety, will 

have no effect on listed species or species proposed for listing, and would not affect designated habitat or 

habitat proposed for designation. Because of this no-effect determination, consultation under Section 

7(a)(2) of the Act or the concurrences of the USFWS or NMFS are not required.

4.3.4 Human Health

Human health considerations are those related to (1) the safety and nutritional value of foods derived from 

biotechnology-derived crops, and (2) the potential health effects of pesticides that may be used in crop

production. As for food safety, consumer health concerns are in regard to the potential toxicity or 

allergenicity of the introduced genes/proteins, the potential for altered levels of existing allergens in 

modified plants, or the expression of new antigenic proteins (substances capable of stimulating an 

immune response). Some consumers may be concerned about the potential consumption of pesticide

residues on/in foods derived from biotech crops. Occupational exposure to pesticides is also considered.

4.3.4.1 Food Safety

The safety assessment of biotechnology-derived crop plants includes characterization of the 

physicochemical and functional properties of the introduced gene(s) and gene products, determination of 

the safety of the gene products (e.g., proteins, enzymes), and compositional assessment of the plant.

Compositional assessments compare the biotechnology-derived crop plant with conventional varieties of 

that crop, and evaluate characteristics such as moisture, protein, fat, carbohydrates, ash, minerals, dietary 

fiber, essential and non-essential amino acids, fatty acids, vitamins, and antinutrients. 

Safety and compositional assessments comparing biotechnology-derived and conventionally bred corn are 

typically performed using the principles and guidelines outlined in the Codex Alimentarius (Codex), 

established by the World Health Organization and Food and Agriculture Organization of the United 

Nations, and Organization for Economic Co-operation and Development (OECD) consensus documents 

for specific crop varieties (e.g., for corn (OECD 2003)). The FDA participates and exercises leadership in 

the Codex Commission. The Codex is a set of international standards, principles, and guidelines for the 

safety assessment of foods derived from plants that were modified using biotechnology based techniques 

(WHO-FAO 2009). These standards help countries coordinate and harmonize review and regulation of 

foods derived from biotechnology-derived plants to ensure public health and facilitate international trade. 

Currently, the Codex Commission is comprised of over 180 member countries, to include the United 

States. Most governments incorporate Codex principles and guidelines in their review of foods derived 

from biotechnology-derived crop plants. 

As summarized in Section 1.3 – Coordinated Framework for the Regulation of Biotechnology, the FDA 

created a voluntary premarket food safety consultation process in the 1990’s. This consultation process 

enables developers of new crop varieties to engage with the FDA to ensure the safety of food and feed 

products derived from the biotechnology-derived crop (US-FDA 1992a, 2006). Pioneer completed a 

food/feed safety consultation with the FDA in 2022; the FDA had no questions concerning human or 

animal food derived from DP23211 corn (US-FDA 2022).

In addition to the FDA consultation, foods derived from plant varieties developed using genetic 

engineering undergo a safety evaluation among international agencies before entering foreign markets, 
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such as reviews by the European Food Safety Agency (EFSA 2020) and the Australia and New Zealand 

Food Standards Agency (ANZFS 2020). These reviews likewise adhere to Codex standards.

4.3.4.2 Safety of the Herbicide Resistance and Insect Resistance Traits

PAT Safety Evaluations: Glufosinate-Ammonium Resistance

PAT, as an introduced trait in crop plants, can be encoded by the bar gene derived from the naturally 

occurring soil bacterium Streptomyces hygroscopicus, and by the pat gene derived from S. 

viridochromogenes. Streptomyces are gram-positive bacteria of the actinomycetal order with more than 

600 species described in soils, sediments, and seawater (Labeda et al. 2012; Bontemps et al. 2013). The 

gene encoding the PAT protein in DP23211 corn was isolated from Streptomyces viridochromogenes, 

which occurs predominantly in soils (Liu et al. 2013; GCM 2019). Because the PAT enzyme occurs 

naturally in soils, it stands to reason that wildlife and humans, globally, have been and are potentially 

exposed, incidentally, to the pat gene and PAT enzyme through environmental sources on a daily basis 

(e.g., incidental ingestion, inhalation).

APHIS has evaluated and deregulated 11 varieties of corn comprised of either the pat or bar genes, as 

well glufosinate resistant varieties of soybean, cotton, canola, beet (USDA-APHIS 2022a). There are no 

human health or ecological risks associated with exposure to PAT; the enzyme has a long history of safe 

use in commercially produced corn, soybean, and cotton varieties. The FDA has previously consulted on 

PAT, and the pat and bar genes encoding for expression of PAT, for over 30 glufosinate resistant crop 

varieties (US-FDA 2020); these include canola, corn, cotton, soybean, and sugar beet. None of these 

modified crop varieties have been identified as presenting any risk to human or animal health. Previous 

evaluations of PAT have shown that it does not share amino acid sequence similarity to known toxins, nor 

does it possess characteristics associated with food allergens (Herouet et al. 2005; ILSI-CERA 2011).

Due to the negligible human health risks associated with PAT, the EPA granted an exemption from the 

requirement of a tolerance for PAT when used as plant-pesticide inert ingredients in all food commodities

(40 CFR § 174.522).

Safety of DvSSJ1 dsRNA

There are no health hazards associated with consumption of DNA/RNA in foods. The mediators of RNAi, 

such as dsRNA, small interfering RNAs (siRNA), and microRNAs (miRNA), are present in all commonly 

consumed plant and animal based foods (Ivashuta et al. 2009; Petrick et al. 2013; Frizzi et al. 2014; 

Wagner et al. 2015). It follows, dietary nucleic acids, to include dsRNAs, are safely consumed on a daily 

basis worldwide—this includes plant dsRNAs with nucleic acid sequences complementary to human 

genes/transcripts (Ivashuta et al. 2009; Jensen et al. 2013; Dever et al. 2015). The FDA concluded that 

nucleic acids introduced into crop plants, in and of themselves, present no safety concerns (US-FDA 

1992b).

IPD072Aa Protein Safety Evaluations

Bioinformatic assessment of the IPD072Aa protein sequence for potential allergenicity was conducted 

according to Codex guidelines (CODEX 2003; Pioneer 2020). The comparisons of the IPD072Aa protein 

sequence to the allergen sequences found no association between the IPD072Aa protein and potential 

allergenicity. 
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The potential toxicity of the IPD072Aa protein was assessed by comparison of its nucleic acid sequence 

to the sequences in the Pioneer toxin database (Pioneer 2020). No alignments were returned between the 

IPD072Aa protein sequence and sequences in the toxin database that suggested an association between 

the IPD072Aa protein and potential toxicity.

Carlson et al. (2019) conducted a 14-day acute oral toxicity study in mice using IPD072Aa protein. The

IPD072Aa protein produced no evidence of adverse effects following administration of 2000 mg/kg body 

weight/day. There were no instances of clinical abnormalities, changes in body weight, or mortality 

observed in any of the animals. The concentration of IPD072Aa protein in DP23211 corn is 0.51 to 4.8 

ng/mg tissue dry weight (dw) in grain and 0.054 to 39 ng/mg tissue dw in leaf (depending on growth 

stage). At these levels, humans or other animals could not consume enough grain or leaf tissue via diet to 

obtain an exposure of 2000 mg/kg body weight/day. 

Phosphomannose Isomerase Safety Evaluations 

Phosphomannose isomerase (PMI) is an evolutionary conserved enzyme found in various taxa including 

bacteria, fungi, insects, some species of plants and nematodes, and mammals—including humans (de 

Lonlay and Seta 2009; Hu et al. 2016a). In eukaryotes it is involved in carbohydrate metabolism, in 

prokaryotes it is involved in a variety of metabolic pathways including polysaccharide biosynthesis.

The PMI protein produced in DP23211 corn is encoded by the native pmi gene from E. coli (Pioneer 

2020). In DP23211 corn, the pmi gene was used as a selectable marker in modification of this corn variety 

(Pioneer 2020). Plant cells lacking this enzyme are incapable of surviving on a mannose (sugar) based 

growth medium used to culture plant cells. Plant cells expressing the pmi gene/PMI are capable of growth 

in a mannose medium, which utilize mannose as a carbon source. PMI as a selectable marker has been 

previously used in corn and rice, crops that have been evaluated for food safety by the FDA (see FDA 

Biotechnology Consultations 113 and 128, and 158, respectively (US-FDA 2019c)). As described further

below, due to its inherent safety (endogenously expressed in prokaryotes and eukaryotes), PMI is exempt 

from the requirement of a tolerance in food and feed. 

4.3.4.3 Pesticides, PIPs, Tolerance Limits for Foods, and Exemption from the Requirement for 

a Tolerance

The EPA regulates the sale, distribution, and use of pesticides under FIFRA (Section 1.3–Coordinated 

Framework). Before a pesticide may legally be used in the United States the EPA must evaluate the 

pesticide to ensure that it will not result in an unreasonable risk to human health or the environment. 

Pesticides that complete this evaluation are issued a "registration" that permits their sale and use 

according to requirements set by the EPA.

Before a pesticide can be used on a food crop, the EPA, pursuant to the FFDCA and Food Quality 

Protection Act of 1996 (FQPA), also establishes a tolerance limit, which is the amount of pesticide 

residue allowed to remain in or on each food commodity (21 U.S. Code § 346a - Tolerances and 

exemptions for pesticide chemical residues). Pesticide tolerance limits established by the EPA are to 

ensure the safety of food and feed for human and animal consumption. If pesticide residues are found 

above the tolerance limit, the commodity will be subject to seizure by the government.
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Section 408(c)(2)(A)(i) of the FFDCA allows the EPA to establish an exemption from the requirement for 

a tolerance if the EPA determines that the exemption is “safe.” Safe is defined as meaning that there is a 

"reasonable certainty that no harm will result from aggregate exposure to the pesticide residue." To make 

a safety finding, the EPA considers, among other things; the potential toxicity of the pesticide and its 

break-down products, aggregate exposure to the pesticide in foods and from other sources of exposure, 

and any special risks posed to infants and children. 

Both the FDA and USDA monitor foods for pesticide residues to enforce tolerance limits and ensure 

protection of human health. The USDA Pesticide Data Program (PDP) collects data on pesticides residues 

on agricultural commodities in the U.S. food supply, with an emphasis on those commodities commonly

consumed by infants and children (USDA-AMS 2020). The Monitoring Programs Division administers

PDP activities, including the sampling, testing, and reporting of pesticide residues on agricultural 

commodities in the U.S. food supply. The program is implemented through cooperation with state 

agriculture departments and other federal agencies. The EPA uses PDP data to prepare pesticide dietary 

exposure assessments pursuant to the FQPA. PDP data:

• enable the EPA to assess dietary exposure;

• facilitate the global marketing of U.S. agricultural products; and

• provide guidance for the FDA and other governmental agencies to make informed decisions.

The EPA has established tolerance limits for glufosinate at 40 CFR §180.473, for a wide variety of 

commodities, including field corn for grain and forage (US-EPA 2019k). 

Due to the negligible risk PAT and PMI pose to human health, summarized above, the EPA has issued 

permanent exemptions for the requirement of a tolerance limit in all food commodities in the United 

States (40 CFR §174.522 and 40 CFR § 174.527, respectively). Nucleic acids, because they are normal 

components of human and animal diets and have a history of safe consumption in food and feed, are also

exempt from the requirement of a tolerance (40 CFR §174.507). Pioneer has submitted a registration 

application to the EPA Biopesticides and Pollution Prevention Division (BPPD) under FIFRA Section 3

for the DvSSJ1 dsRNA and the IPD072Aa protein. This submission included a petition for exemption 

from the requirement of a tolerance for the IPD072Aa protein under the FFDCA.

15 The DvSSJ1 dsRNA is 

exempt from the requirement of a tolerance under 40 CFR 174.507.

The EPA also sets limits for potential drinking water contaminants that need to be regulated in order to 

protect public health (40 CFR part 141). These contaminant limits are required by the Safe Drinking 

Water Act (SDWA). The EPA works with States, Tribes, and many other partners to implement SDWA 

standards.

4.3.4.4 Worker Safety 

Agricultural worker hazards are primarily those associated with potential pesticide exposure, and the 

operation of farm machinery and other equipment. Agricultural operations are covered by several 

15 Federal Register / Vol. 85, No. 73 / Wednesday, April 15, 2020 / p. 20910: EPA, 40 CFR Part 180, Receipt of a 

Pesticide Petition Filed for Residues of Pesticide Chemicals in or on Various Commodities (February 2020). 

https://www.govinfo.gov/content/pkg/FR-2020-04-15/pdf/FR-2020-04-15.pdf
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Occupational Safety and Health standards including Agriculture (29 CFR 1928), General Industry (29 

CFR 1910), and the General Duty Clause. Further protections are provided through the National Institute 

of Occupational Safety and Health (NIOSH).

To address the potential hazards associated with exposure to pesticides during field application and 

handling the EPA issued the Worker Protection Standard (WPS) (40 CFR Part 170) in 1992. The WPS 

contains requirements for pesticide safety training, notification of pesticide applications, personal 

protective equipment, restricted entry intervals following pesticide application, decontamination supplies, 

and emergency medical assistance. OSHA also requires employers to protect their employees from 

hazards associated with pesticides. 

In November 2015, the EPA revised the WPS to decrease pesticide exposure incidents among agricultural 

workers, handlers, and their families (80 FR 211, November 2, 2015, p. 67495). The revised WPS 

requirements went into effect during 2017–2018. On October 30, 2020, the EPA finalized narrow updates 

to the Application Exclusion Zone (AEZ) provisions under the Worker Protection Standard regulation.

4.3.4.5 Potential Effects on Human Health

As discussed below there are no food safety issues associated with the consumption of DP23211 corn 

products. Production of DP23211 corn seed/hybrids would present the same potential risks to public 

health and worker safety as production of other corn varieties. Risks to public health would be those 

associated with the potential contribution of crop production to impacts on air and water quality (e.g., 

runoff of pesticides and fertilizers into surface waters, leaching of pesticides into groundwater, drift of 

pesticides offsite). Risks to worker safety would be in relation to pesticide mixing and application. 

DP23211 Corn Food Products and Consumption

Direct consumption of corn in the United States is primarily that of corn on the cob (sweet corn; Zea mays

convar. saccharata var. rugosa) and popcorn (flint corn; Zea mays var. everta), and in certain areas grits 

or hominy (dent corn; Zea mays var. indentata). Humans also consume corn products such as corn meal, 

corn oil, and corn syrup in food items such as cereals, salad dressings, and snack foods. While most dent 

corn is grown for animal feed and production of fuel ethanol, certain dent corn hybrids with specific 

starch properties are used for food purposes—generally referred to as food grade corn. There are various 

dent corn varieties that have been developed—bred—for specific purposes/markets and given 

designations to distinguish which markets the grain is suited for. For example, HAE – High Available 

Energy (Pork & Poultry Feed); HTF – High Total Fermentables (Dry-Grind Ethanol); HES – High 

Extractable Starch (Wet Milling); WX – Waxy (starch for industrial and food uses); WH – White food 

corn; and YFC – Yellow food corn. Hence, varieties of dent corn designated WX, HES, WH, and YFC 

are used for food purposes. These are typically contracted and sold to wet-millers and dry-millers for 

processing into tortilla chips, corn starch, grits, corn syrup, corn oil, and other corn products.

DP23211 corn could potentially be used for production of food grade hybrids and processed into starch, 

grits, meal, flour, oil, and sweetener products. As discussed previously (4.3.4.2), there are no risks to 

human health associated with the DvSSJ1 dsRNA, and the IPD072Aa, PAT, and PMI proteins. 

Compositional analyses of DP23211 corn grain demonstrate that it is nutritionally equivalent to other dent 

corn varieties (Pioneer 2020). A voluntary safety and nutritional assessment for DP23211 corn was 

submitted to the FDA’s Center for Food Safety and Applied Nutrition in 2019 (Pioneer 2020). Pioneer
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completed a food safety consultation with the FDA in 2022; the FDA had no questions concerning human 

food derived from DP23211 corn (US-FDA 2022).

The National Bioengineered Food Disclosure Law (NBFDL), passed by Congress in July of 2016, 

directed USDA to establish a national mandatory standard for disclosing foods that are or may be 

bioengineered. The mandatory compliance date was January 1, 2022. The Standard requires food 

manufacturers, importers, and certain retailers to ensure bioengineered foods are appropriately disclosed. 

Any food products derived from DP23211 corn would require labeling subject to NBFDL standards, and 

consumers would choose to consume such foods based on preference. 

The EPA WPS regulations provide protections to agricultural workers, pesticide handlers, and other 

persons via training, pesticide safety and hazard communication requirements, personal protective 

equipment requirements, and provision of supplies for routine washing and emergency decontamination. 

Agricultural workers and handlers, owners/managers of agricultural establishments, commercial (for-hire) 

pesticide handling establishments, and crop production consultants are provided guidance for compliance 

with WPS regulations (US-EPA 2016a).

4.3.5 Livestock Health and Welfare

The term livestock is defined in different ways, although for the purposes of this EA livestock means all

domesticated animals reared in an agricultural setting to produce commodities such as meat (e.g., pork, 

poultry, fish), eggs, milk, leather, and wool. Horses, which provide labor, are also considered livestock in 

the United States.

Dent corn accounts for around 90% to 95% of feed grain in the United States on an annual basis; it is a 

primary feed source for beef and dairy cattle, poultry, and hogs. Animal feed derived from dent corn 

comes not only from the grain, but also from silage (the above-ground portions of the corn plant), stalk 

residues in fields that might be grazed, and residuals derived from corn refining and milling, such as corn 

gluten feed, corn gluten meal, corn germ meal, corn steep liquor, and amino acids.

4.3.5.1 Potential Effects on Livestock Health and Welfare

If used for animal feed, DP23211 corn/progeny would be expected to be of benefit to animal health and 

welfare. As discussed for human health, there are no risks to food animal health and welfare that are 

associated with the DvSSJ1 dsRNA, IPD072Aa, PAT, and PMI traits present in DP23211 corn. The 

nutrient composition of grain and forage samples derived from DP23211 corn and a near-isogenic control 

corn was evaluated. The compositional analyses of grain included crude protein, crude fat, crude fiber, 

ash, carbohydrates, fatty acids, total amino acids, key anti-nutrients, and key secondary metabolites. 

Compositional analyses of forage included crude protein, crude fat, crude fiber, ash, carbohydrates, 

calcium, and phosphorus. No statistical differences were observed in any of the analytes measured in 

DP23211 corn and as compared to other dent corn varieties. Based on these analyses, the grain and forage

of DP23211 corn are comparable to conventional corn with respect to nutrient composition (Pioneer 

2020). Pioneer completed an animal feed safety consultation with the FDA in 2022; the FDA had no 

questions concerning feed derived from DP23211 corn (US-FDA 2022).
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4.3.6 Socioeconomics

4.3.6.1 Domestic and International Markets

U.S. Dent Corn Commodities

The production of corn and the various corn derived commodities utilized by the food, feed, fuel and 

industrial sectors is major component of the U.S. economy. In 2019, the United States produced 13.7

billion bushels of corn for grain (USDA-NASS 2020a) with a market value of $51.5 billion (USDANASS 2019b). The primary dent corn commodities are animal feed and fuel ethanol, which account for 

around 38% – 48%, and 25% – 35% of use, respectively. The remainder is processed for food and 

industrial products. During processing, corn is either wet or dry milled depending on the desired end 

products: 

• Wet millers process corn into high fructose corn syrup (HFCS), glucose and dextrose, starch, corn 

oil, beverage alcohol, industrial alcohol, and fuel ethanol.

• Dry millers process corn into flakes for cereal, corn flour, corn grits, corn meal, and brewers grits 

for beer production. 

Both the dry-milling and wet-milling methods of corn processing generate economically valuable coproducts, the most prominent of which are distillers' dried grains with solubles (DDGS), which can be 

used as a feed ingredient for livestock (USDA-ERS 2019). In the United States, feed for both dairy and 

beef cattle has been the primary use of DDGS, but increasingly larger quantities of DDGS are making 

their way into the feed rations of hogs and poultry (USDA-ERS 2019).

Dent/field corn accounts for around 70% to 90% of total U.S feed grain production and use on an annual 

basis (DIS 2017). The other three major feed grains are sorghum, barley, and oats. Across the United 

States, more than 9.6 billion food-producing animals are raised annually. These include broilers, turkeys, 

egg-laying hens (layers), hogs, dairy cows, cattle, fish (aquaculture), and sheep, all of which are raised on 

corn-based feeds (DIS 2017). Around 120 to 140 million tons of corn grain per year are used in feeds for 

these animals (DIS 2017).

Ethanol

The Renewable Fuel Standard (RFS) is a federal program that requires transportation fuel sold in the 

United States to contain a minimum volume of renewable fuels. It originated with the Energy Policy Act 

of 2005 and was expanded by the Energy Independence and Security Act of 2007. Congress created the 

RFS program to reduce greenhouse gas emissions and expand the nation’s renewable fuels sector while 

reducing reliance on imported oil. The EPA implements the program in consultation with the USDA and 

the Department of Energy (US-EPA 2020l). 

The RFS requires renewable fuel to be blended into transportation fuel in increasing amounts each year, 

escalating to 36 billion gallons by 2022. The four renewable fuel categories under the RFS are: biomassbased diesel, cellulosic biofuel, advanced biofuel, and total renewable (conventional) fuel, the latter of 

which typically refers to ethanol derived from corn starch. The RFS began mandating the use of corn 

ethanol in U.S. fuels in 2006.
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U.S. corn processing capabilities allow for production of fuel ethanol and DDGS on a level currently 

unmatched by any other country. The ethanol industry was comprised of approximately 205 plants in 27 

states with a production capacity of 17.1 billion gallons as of 2019. The United States produced 15.8 

billion gallons of corn ethanol in 2019, this comprised 54% of global corn ethanol production (RFA 

2019). The industry created $23.3 billion in household income and contributed $43 billion to the national 

Gross Domestic Product (RFA 2020).

Industrial products 

Corn wet-mill and dry-mill are also used to produce a variety of industrial products, such as soaps, paints, 

corks, linoleum, polish, adhesives, rubber substitutes, wallboard, dry-cell batteries, textile finishings, 

cosmetics, candles, dyes, pharmaceuticals, lubricants, insulation, and wallpaper.

HR Crops

HR crops have proven economically beneficial (Brookes and Barfoot 2018b). Globally, the adoption of 

HR corn has mainly resulted in lower costs of production, although yield gains from improved weed 

control have arisen in Argentina, Brazil, the Philippines, and Vietnam (Brookes and Barfoot 2018b). In 

the United States, the average gross farm income benefit from using HR corn (after deduction of cost of 

technology) has been around $12.2/acre (Brookes and Barfoot 2018b). During the 1996-2018 timeframe, 

the aggregate income benefit from using HR corn in the United States has been estimated to be around 

$10.8 billion (Brookes and Barfoot 2018c).

Globally, the total aggregate farm income gain from using HR corn during the 1996–2018 time frame was

$17 billion (Brookes and Barfoot 2018c). Within this, $6.1 billion (36%) was due to yield gains and the 

rest derived from lower costs of production (Brookes and Barfoot 2018c).

Herbicide Resistant Weed Costs

Currently, HR weeds may be costing U.S. growers as much as $2 billion a year in decreased yields, 

increased input costs, and decreased land values, according to University of Wisconsin extension weed 

scientist Vince Davis (Van Deynze et al. 2020). Herbicide resistance can increases growers’ chemical 

costs by 30%-40% as they try to maintain weed control (Weaver 2019). Reported costs to farmers for 

control of HR weeds range from $14 to $150 per acre, dependent on the weed species present (e.g., once 

Palmer amaranth gets above 6 inches tall—it can reach 6 ft in height at maturity—there’s no herbicide 

that will control it), prevalence of HR weed populations, and number of herbicide MOAs to which it is 

resistant (Hurley et al. 2010; Hembree 2011; Livingston et al. 2015; Bayer-CropSci 2018). HR weeds are 

not unique to HR crops, development of HR weeds has been an issue since the widescale use of chemical 

herbicides in the 19050s.

IR crops

IR crops have proven effective in control of insect pests, and economically beneficial, thus the extent of

their adoption in the United States (USDA-ERS 2022a). From 1996 to 2018, IR corn targeting corn 

boring pests provided a 7% increase in yield, and increased farm income by $81/ha ($32/acre). IR corn 

targeting CRW provided a 5% increase in yield, and increased farm income by $78/ha ($31.6/acre)

(Brookes and Barfoot 2018c). In 2018, the global gross farm income gains from using IR corn in 2018 
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were $4.53 USD billion (Brookes and Barfoot 2018c). At the aggregate level, the global gross farm 

income gains from using IR corn was $4.5 billion (Brookes and Barfoot 2018c).

Another economic benefit derived from IR crop varieties is the area wide suppression of insect pest 

populations. In areas where cultivation of Bt corn and Bt cotton is high there has been observed a

reduction in insecticide use and associated costs in adjacent cropping systems cultivating non-Bt 

varieties—a result of the area-wide suppression of insect pest populations (NAS 2016). For example, 

several studies have found that the use of Bt corn and Bt cotton are positively associated with the areawide suppression European corn borer and pink bollworm, respectively (e.g., see review by (FernandezCornejo et al. 2014b)). In general, current peer review literature and other reports indicate that cultivation 

of Bt crops can potentially provide tangential benefits to adjacent farms by tempering the prevalence of 

certain insect pest populations, reducing the need for insecticide use in nearby cropping systems, and the 

associated costs (Dively et al. 2018; Frisvold 2019).

International Trade

The United States is the world's largest corn producer providing over a third of the total supply of corn in 

the world market. Field (dent) corn is the largest component of global coarse grain trade—other grains 

include sorghum, barley, oats, rye, millet, and mixed grains—generally accounting for about two-thirds of 

the volume over the past decade (USDA-ERS 2019). Field corn grain exports represent a principal source 

of demand for U.S. producers and make the largest net contribution to U.S. agricultural trade for all 

agricultural commodities—reflective of the importance of field corn exports to the U.S. economy. The 

United States currently exports between 10% and 20% of its annual production (USDA-ERS 2019). In 

2019, around 14.3% of production (13.7 billion bushels) was exported to more than 73 different countries

(USGC 2020a), at an estimated value of around $7.6 billion (USDA-FAS 2020). The United States 

produces more ethanol and DDGS than consumers and industry can use, providing an ample export 

supply. As a result, the United States dominates trade in these two corn-based commodities. In 

2018/2019, 1.55 billion gallons of U.S. ethanol—548 million bushels in corn equivalent—were exported 

to 69 countries (USGC 2020b). U.S. corn processed into fuel ethanol and DDGS generates around $4 to 

$5 billion in trade annually (USDA-FAS 2019).

U.S. corn exports are expected to remain steady over the next decade, largely due to demand for feed 

grains in support of meat production, and fuel ethanol (WAOB-IAPC 2020).

Identity Preservation

As food, feed, fuel, and industrial crop commodities and production systems have diversified to meet 

market demands, the need for segregation and identity preservation of agricultural commodities has 

increased. Farmers who grow corn that is used for different purposes in the same general area need to 

communicate and plan with their neighboring growers to ensure their crop commodity identities are 

preserved and price premiums can be realized (e.g., specialty starch corn, waxy corn, high lysine corn, 

blue corn). Identity preservation (IP) refers to a system of production, handling, and marketing practices 

that maintains the integrity and purity of various agricultural commodities (Sundstrom et al. 2002). IP

typically involves independent, third-party verification of the identification, segregation, and traceability 

of a product's unique, value-added characteristic (USDA-AMS 2019). Verification is provided at every 

stage, including seed, production, processing, and distribution. Seed certification programs such as that 
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used by the Association of Official Seed Certifying Agencies (AOSCA) play a major role in maintaining 

seed purity standards at levels established by the industry for national and international trade (Sundstrom 

et al. 2002). Similarly, commodity traders, marketing organizations, and food processors have established 

purity and quality standards for specific end-product uses. 

IP is important to international trade. The low-level presence (LLP) or adventitious presence (AP) of 

biotechnology-derived trait material in internationally traded conventional, organic, or other 

biotechnology-derived crop commodities can disrupt trade and incur economic losses. LLP refers to the 

unintended presence, at low levels, of biotechnology-derived crop material that is authorized for 

commercial use or sale in one or more countries, but not yet authorized in an importing country. AP refers 

to instances when trace amounts of biotechnology-derived crop material that has not been approved for 

commercial use by any country is found in the commercial crop or food supply.

Asynchronous approvals—some countries may lag approval for import of biotechnology-derived corn

varieties— and zero tolerance policies can result in the diversion of trade by some exporters, and rejection 

or market withdrawals by importers of corn. Consequently, incidents of LLP or AP can lead to income 

loss for exporters and consequently for producers, and consumers in importing countries can potentially 

face higher domestic prices when an import is deterred or directed to another trading partner (Atici 2014). 

The challenges associated with maintaining product identity in international trade can also increase costs, 

as well as the premiums paid, for certain biotechnology-derived crops.

In general, LLP/AP or compromise of corn commodity identity can cause disruptions in international 

trade when biotechnology-derived crop material is inadvertently incorporated into food or feed shipments. 

As such, countries producing biotechnology-derived crop varieties are required to take those measures 

necessary in the production, harvesting, transportation, storage, and post-harvest processing of 

biotechnology-derived crops to avoid the potential for LLP/AP in conventional or organic crop 

commodities.

4.3.6.2 Potential Socioeconomic Impacts

4.3.6.2.1 Crop Protection and Yield

DP23211 corn could be cultivated to produce corn-based food, feed, fuel, and industrial products. 

DP23211 corn would provide protection against corn rootworm (yield), an economically significant pest 

in corn, and as a glufosinate resistant variety, may prove useful in the management of weeds, and HR 

weeds and their development. To the extent this HR/IR varietal facilitates insect pest and weed 

management, and obtaining optimal yields, it would be expected to support growers achieving optimal 

net-returns on crop production and limiting commodities costs. 

These factors considered, the potential impacts of DP23211 corn on domestic markets would be largely 

beneficial. There are no adverse economic impacts associated with the introduction of DP23211 corn to 

commercial markets, crop production, or crop protection. Corn rootworm is a significant crop pest in the 

United States that can cause economic losses exceeding $1 billion annually, resulting from both 

management costs and yield losses (Shrestha et al. 2018). Corn rootworm damage has historically been 

managed with crop rotation, broad-spectrum soil insecticides, and transgenic crops expressing Bt Cry 

proteins. 
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As with synthetic chemical pesticides, insects are capable of developing resistance to Cry toxins—

including those targeting corn rootworm. As adoption of Cry based IR corn increased over the last 20 

years, without fully implemented insect resistance management (IRM) planning, the selection pressure on

insects resistant to Cry toxins, or evolving resistance, became greater (Cullen et al. 2013). Field-evolved 

resistance by corn rootworm to Cry3Bb1 corn, mCry3A corn, and eCry3.1Ab corn has been documented 

in multiple Midwestern states (Gassmann et al. 2016; Jakka et al. 2016). Insect resistance to transgenic 

Cry traits can pose a threat to the long-term viability of the trait (US-EPA 2020j). New modes of action in 

PIPs targeting corn rootworm would be beneficial in maintaining sustainable corn rootworm management 

strategies in U.S. crops (Gassmann et al. 2016; Niu et al. 2017). DP23211 corn would diversify the 

currently available Cry protein-based MOA for corn rootworm control through the combination of an 

RNAi mediated MOA and new IPD072Aa protein MOA. Because DP23211 corn would provide farmers 

with an additional control option for management of corn rootworm—diversify PIP MOAs for control of 

corn rootworm—it would be expected to provide economic benefits to growers and corn markets by 

protection of corn grain yields, and helping sustain the efficacy of Cry3 based corn varieties. 

4.3.6.2.2 Beneficial Insect Populations

Biological control of plant pests provided by populations of predator and parasitoid species is an 

invaluable ecosystem service. It is an underlying pillar of IPM, and likely provides one of the highest 

returns on investment in IPM, yet its economic value has rarely been estimated (Naranjo et al. 2015). 

One seminal estimate valuing biological control, as an ecosystem service, arrived at a value of around 

$400 billion per year worldwide (Costanza et al. 1997). Studies providing sufficient data to estimate a 

value for arthropod natural enemies alone are rare and generally have valuated the avoided-costs of 

insecticides, which, for an array of cropping systems have ranged from $0/acre to $918/acre ($2,202/ha).

Conservation biological control involves changes to the crop environment, such as the landscape in which 

the crop is embedded, to favor the abundance and pest-suppression activity of native or introduced natural 

enemies.16 This involves minimizing factors that can harm natural enemies and/or providing them 

additional food and shelter (Naranjo et al. 2015). Cropland estimates for conservation biological control

have suggested a value of around $14/acre ($33/ha) to $45/acre, although for cotton crops the value can 

be substantially higher (Pimentel et al. 1997; Naranjo et al. 2015). Losey and Vaughan (2006) estimated a 

value of $4.5 billion annually for the natural biological control of crop pests in the United States (Losey 

and Vaughan 2006), but this estimate may be very conservative (Landis et al. 2009).

In addition to functioning as biological controls for crop pests through predation and parasitism, 

beneficial insects provide pollination for more than two-thirds of the world ́s cultivated plant species 

(Costanza et al. 1997). In the United States, the value of the pollination services has been estimated to be 

between $5 and $14 billion per year (Southwick and Southwick Jr 1992; Morse and Calderone 2000), 

16 There are several approaches to biological control: natural, classical, augmentative, and conservation. Natural 

means the control of insect pests by predators and parasitoids as an ecosystem service. Classical means the 

intentional introduction of an exotic biological control agent for permanent establishment and long-term pest 

management. Augmentative means the release of additional numbers of a natural enemy when too few are 

present to control a pest effectively. Conservation means the intentional management of a landscape to support 

beneficial species.
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from which a large proportion is attributed to insect pollinators (Losey and Vaughan 2006; González et al. 

2016). 

Insecticides are one of the more important and widely used tactics in IPM, but they can also become 

barriers to effective biological control. IR crops incorporating PIPs targeting specific species of insects, 

and which are less reliant on chemical insecticides, generally have fewer impacts on arthropod 

biodiversity in and around crop fields, relative to broad-spectrum chemical insecticide based cropping 

systems (Gatehouse et al. 2011; Romeis et al. 2019). While DP23211 corn would reduce populations of 

Diabrotica virgifera virgifera, which could have some indirect cascading/trophic effects on beneficial 

predator/parasitoid populations (e.g., loss of prey) (Chaplin-Kramer et al. 2011; Letourneau et al. 2011; 

González et al. 2016), this would not be expected to result in deleterious effects on beneficial insect 

populations in DP23211 corn crops, or adjacent crops. Predators of Diabrotica virgifera virgifera include 

beetles (Carabidae, Staphylinidae, Dermestidae), mites (Hypoaspis aculeifer), ants (Lasius neoniger, 

Myrmica americana, Pheidole bicarinata), and spiders (Araneae) (Kuhlmann and Burgt 1998; CABI 

2020), all of which feed on range of species (Adalbert et al. 2008; Carvalho et al. 2017; Gathalkar and 

Sen 2018; Raupp et al. 2021). For example, beetles (Pterostichus species, Poecilus species, Scarites

quadriceps), spiders, and mites are common predators of rootworm larvae and eggs (Lundgren 2010; 

Spagnol et al. 2020). Ground beetle feeding preferences are generally not fixed; most carabids will 

opportunistically feed on whatever food is available (Hodgson and Patterson 2007). Pterostichine species, 

including members of the genera Pterostichus and Poecilus, are the most diverse consumers, known to 

feed upon slugs, aphids, moth larvae, beetle larvae, and weed seeds (Jones et al. 2013). Predatory mites 

are increasingly used in biocontrol and consume large numbers of other pest mites (Xu and Enkegaard 

2010; Schausberger et al. 2018). Spiders are opportunistic hunters and feed on a variety of insect prey. 

Thus, any cascading/trophic effects on Diabrotica virgifera virgifera predatory species would most likely 

be adaptive in nature, were predators fed on other prey available—prey other than corn rootworm. 

In general, PIP based insecticidal crops such as DP23211 corn, for the most part, have the potential to be 

more environmentally benign than chemical insecticide-based pest management approaches (Gatehouse et 

al. 2011). While biodiversity will be inherently limited in commercial corn crops due to frequent 

disturbance, tillage, mechanized planting, planting of a monoculture crop, and application of fertilizers 

and pesticides, HR/IR crops have generally reduced the environmental impacts of crop production (NRC 

2010; Carpenter 2011; NAS 2016; Romeis et al. 2019). Glufosinate use would be subject to EPA label 

requirements, no different than for other corn crops.

4.3.6.2.3 Environmental Justice

Environmental justice (EJ) refers to the just treatment and meaningful involvement of all people, 

regardless of income, race, color, national origin, tribal affiliation, or disability, in federal agency 

decision-making and other activities that may affect human health and the environment. All people 

require equitable access to a healthy, sustainable, and resilient environment in which to live, play, work, 

learn, grow, worship, and engage in cultural and subsistence practices. 

Communities with EJ concerns can experience disproportionate and adverse human health or 

environmental burdens. These burdens can arise from a number of causes, including inequitable access to 

clean water, clean air, resources for other basic human health and environmental needs, and increased 

exposure to pollution, hazardous waste, or toxic substances. Communities with EJ concerns may be 
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comprised of a significant proportion of people who have low incomes or are minorities, including 

individuals who are Black, Latino, Indigenous and Native American, Asian American, Native Hawaiian, 

and Pacific Islander. 

Benefits to Small-Scale Farmers

The main goals of sustainable agriculture are to produce high yields of healthy crop products, efficiently 

use environmental resources in production of the crop with minimal environmental impacts, enhance 

quality of life through provision of food security and the just distribution of food, and provide economic 

benefits for farmers (Tseng et al. 2020; Abdul Aziz et al. 2022). These goals have become a prominent 

issue in agricultural production, given it can be challenging to produce large amounts of food, with 

minimal environmental degradation (Abdul Aziz et al. 2022).

The introduction of biotechnology-derived crops into commercial markets can create the potential for 

social and economic effects (NAS 2016). For example, there can be some disparity in how biotechnologyderived crops may benefit large- and small-scale farmers. The category of small-scale farmers includes 

those who are resource-poor—constrained in terms of capital and labor—and can include minority and 

low-income farmers. Access to biotechnology-derived crop seed by small-scale farmers and marginalized 

communities can potentially face financial barriers. For farmers who want to grow biotechnology-derived 

crops, the price of biotechnology-derived crop seeds tends to be higher than that of other types of seed 

(NAS 2016), thus, the cost of biotechnology-derived crop seed may limit adoption by small-scale farmers, 

particularly resource-poor farmers. Although biotechnology-derived crop varieties often produce greater 

yields and sometimes reduce other input costs, some studies have found it was not always economically 

feasible for small-scale farmers to adopt biotechnology-derived crops or to continue planting in seasons 

after initial adoption (NAS 2016). 

This limitation considered, in general, based on current studies, existing biotechnology-derived crops 

have been useful to both large-scale farmers of cotton, soybean, corn, and canola, as well a number of 

smaller-scale farmers (NAS 2016). Each of these crops have generally had favorable outcomes in 

economic returns to producers who have adopted these crops (NAS 2016; Brookes and Barfoot 2018c). 

However, benefits have varied widely, and are connected to the institutional context in which these crops

have been deployed, marketed. Small-scale farmers were more likely to be successful with 

biotechnology-derived crops when they also had access to credit, extension services, and markets, and to 

government assistance in ensuring an accessible seed price (NAS 2016). Biotechnology-derived corn, 

cotton, and soybean have provided economic benefits to some small-scale adopters of these crops. 

However, sustained gains will typically—but not necessarily—be expected in those situations in which 

small-scale farmers also have institutional support, such as access to credit, affordable inputs, extension 

services, and markets (NAS 2016). 

Food Security 

Biotechnology-derived crops have also been found to be largely beneficial to supporting food security 

(NAS 2016; Brookes and Barfoot 2018b; Brookes and Barfoot 2020), which is important for 

marginalized, poor, and underserved communities. Food security exists when all people have consistent 

physical and economic access to sufficient, safe, and nutritious food that meets dietary needs and food 

preferences for a healthy life. Food security means (1) food availability (e.g., food production and 
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supply); (2) food access (e.g., availability in physical proximity and economic resources to purchase); (3) 

food utilization (e.g., Sufficient energy and nutrient provided by the food); and (4) food system stability 

(e.g., adequate access to food at all times) (FAO 2014a). For food security objectives to be realized, all 

four dimensions must be fulfilled simultaneously.

Given population growth and rising incomes, it is estimated that the demand for food will rise by 70% to 

100% by 2050. To meet this need, it is estimated that production in developing countries will need to 

almost double (USDA 2023). Biotechnology-derived crops could help to mitigate potential food shortages 

related to population growth and the effects of climate change in specific regions worldwide. For 

example, biotechnology-derived crops could impact food availability by providing seeds which are 

resistant to adverse climate conditions, plant pests, and diseases; bio-fortified crops could increase the 

nutritional status of households worldwide. (Garcia-Yi et al. 2014; NAS 2016). 

In brief, biotechnology-derived crops may be a means of contributing to crop-productivity gains, but the 

effect of biotechnology-derived crops on hunger will depend on development of appropriate crop varieties 

and the appropriate political, social, and cultural context (Anthony and Ferroni 2012; NAS 2016). 

Biotechnology-derived food crops have a record of increasing the potential yield of a crop; 

biotechnology-derived crops that have affected yield have done so by protecting yield (NAS 2016). At the 

subsistence-agriculture level, protection of yield from biotic stresses (insects and pathogens) and abiotic 

stresses (drought and temperature extremes) should decrease the year-to-year variation in food 

availability, which is important in support of food security and prevention of hunger (NAS 2016). 

Biotechnology-derived crops that have already been commercialized have the potential to protect yields 

in places where they have not been introduced, and future biotechnology-derived crops, such as pest and 

disease resistant, and drought tolerant, may protect yields of a wider array of crops (for example, diseaseresistant cassava and climate-resilient rice) (NAS 2016). 

4.3.6.2.4 International Trade

U.S. corn exports—grain, ethanol, DDGS, corn oil, high fructose corn syrup, corn gluten feed and meal, 

corn starch, and corn groats/flour—averaged around 9.5 billion annually from 2015 to 2019 (USDA-FAS 

2019). By facilitating achieving maximum yield and thereby domestic production, the potential impacts 

of DP23211 corn on the commodities pricing and U.S. trade of corn commodities would likely be

beneficial.

As with all biotechnology-derived crop commodities there exists the potential for LLP occurring in 

countries importing U.S. agricultural commodities that have not yet been approved. The issue of 

asynchronous approval (AA), and resulting LLP situations, can lead to trade delays, shipment rejection, 

and costs to traders (FAO 2014b). International trade is facilitated by the World Trade Organization 

(WTO) and the Organization for Economic Cooperation and Development (OECD). Standards and 

guidelines for the safety evaluation and trade of biotechnology-derived crop commodities are established 

under international policy and agreements such as the Codex Alimentarius (FAO 2009), the FAO

International Plant Protection Convention (FAO 2020), WTO Sanitary and Phytosanitary Measures 

(WTO 2020b), WTO Technical Barriers to Trade Agreement (WTO 2020a), and the Cartagena Protocol 

on Biosafety (CBD 2020a). 
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DP23211 corn would be subject to the same international standards and requirements, discussed above, as 

currently traded corn varieties. In general, developers have various legal, reputational, and marketing 

motivations to implement rigorous stewardship measures to ensure IP, prevent commingling, and avoid 

AP and LLP. By necessity, all international and industry standards and requirements must be met for the 

marketing of DP23211 corn commodities. Pioneer is a member of Excellence Through Stewardship®, a 

global organization that promotes product stewardship programs and quality management systems for the 

full life cycle of agricultural biotechnology products (ETS 2020). Pioneer products are commercialized in 

accordance with Pioneer policies regarding stewardship of those products and with Excellence Through 

Stewardship policy. This stewardship program in part helps growers and marketers understand and meet 

their grain and grain byproduct marketing responsibilities and export approvals (Pioneer 2019).

4.3.7 Climate Change and Greenhouse Gas Emissions

The primary sources of greenhouse gas (GHG) emissions in the United States are: Transportation (around 

28% - 29%), electricity production (25% - 27%), industry (22% - 23%), commercial and residential

properties (12% - 13%), and agriculture (10% - 11%). In 2019, U.S. greenhouse gas emissions totaled 

6,558 million metric tons of CO2-eq, or 5,788 million metric tons of CO2-eq after accounting for 

sequestration from the land sector (Figure 4-14). 

Figure 4-14. Sources of U.S. Greenhouse Gas Emissions

Source: (US-EPA 2020b)

GHGs associated with agriculture are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). N2O 

emissions derive from cropped and grazed soils, CH4 emissions from ruminant livestock production and 

rice cultivation, CH4 and N2O emissions from managed livestock waste, and CO2 emissions from on-farm 

energy use. The management of cropped, grazed, and forestland can help offset GHG emissions by 

promoting the biological uptake of CO2 through the incorporation of carbon into biomass, wood products, 

and soils—termed carbon sequestration. Net emissions equate to total GHG emissions minus CO2
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sequestration or removal of CO2 from the atmosphere, including the net forest sink, as well as the net soil 

sink from grazed lands and croplands.

Agricultural emission sources can be grouped into mechanical and non-mechanical (Table 4-18). 

Mechanical sources are equipment or machinery operated on farms, such as mobile machinery (e.g., 

harvesters), stationary equipment (e.g., boilers), and refrigeration and air-conditioning equipment. These 

sources emit CO2, CH4, and N2O, or HFCs and PFCs, and their emissions are determined by the 

properties of the source equipment and material inputs (e.g., fuel composition). Emissions from nonmechanical sources are larger than mechanical sources, with enteric fermentation (CH4) and soils (N2O) 

being the largest sources. Roughly 60% of all N2O emissions and 50% of all CH4 emissions derive from 

non-mechanical agricultural activities, namely agricultural soil management practices and enteric 

fermentation livestock, respectively (US-EPA 2020b). The exact contribution of agriculture to global CO2

emissions is difficult to quantify, because the biomass and soil C pools not only emit large amounts of 

CO2, but also take up CO2 (sequester). Nevertheless, C sequestration offers most of the global emissions 

mitigation potential in agriculture (~89%). 

Table 4-18. Agricultural Emissions Sources

CO2 CH4 N2O

HFCs and 

PFCs

Mechanical 

Purchased electricity1 x x x

Pesticide Production and Use (use under mobile machinery below) x

Mobile machinery, fossil fuel combustion (e.g., tilling, seeding, harvesting, and 

transport) x x x

Stationary machinery (e.g., milling and irrigation equipment) x x x

Refrigeration and air-conditioning equipment: x

Non-mechanical 

Tillage of soils x x x

Addition of synthetic fertilizers, livestock waste, and crop residues to soils x x x

Addition of urea and lime to soils x

Enteric fermentation x

Rice cultivation x

Manure management x x

Land-use change x x x

Open burning of crop residues left on fields x x x

Managed woodland (e.g., tree strips, timberbelts) x

Composting of organic wastes x

Oxidation of horticultural growing media (e.g., peat) x

1. These gases are released during the combustion of fossil fuels, such as coal, oil, and natural gas, to produce 

electricity. N2O emissions from stationary combustion sources result predominantly from the burning of coal at 

electric power plants (8 MMTCO2e, or 60 percent of all nitrous oxide emissions from stationary combustion). 

At the farm scale, the magnitude of different emission sources and GHGs will vary widely depending on 

the type of farm, management practices, and natural factors at play. These factors include land cover; 

farm topography and hydrology; soil microbial density and ecology; soil temperature, moisture, organic 

content and composition; crop or livestock type; cover cropping practices; and land and waste 
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management practices (CLI 2012). It can be difficult to accurately predict the relative magnitude of 

different sources for a given farm, although general sources and patterns of emissions can be expected 

(CLI 2012). 

Together, agricultural sources contributed about 10% of total anthropogenic emissions in 2019—around 

628.6 Million Metric Tons (MMt) of CO2 equivalent (CO2–eq) (Table 4-19). Cropland agriculture is 

responsible for almost half (46%) of all emissions from the agricultural sector (USDA 2016). Methane 

emissions from enteric fermentation and manure management represent around 27% and 9% of total CH4

emissions from anthropogenic activities, respectively. Of all domestic animal types, beef and dairy cattle 

are the largest emitters of CH4. Rice cultivation and field burning of agricultural residues were minor 

sources of CH4. Emissions of N2O by agricultural soil management through activities such as fertilizer 

application and other agricultural practices that increased nitrogen availability in the soil was the largest 

source of U.S. N2O emissions, accounting for around 75% percent. Manure management and field 

burning of agricultural residues are smaller sources of N2O emissions. Urea fertilization and liming 

accounts for around 0.10% and 0.05% of total CO2 emissions from anthropogenic activities, respectively 

(US-EPA 2020c). 

 Table 4-19. Emissions from Agriculture (MMT CO2–Eq) 

Gas/Source 1990 2005 2015 2016 2017 2018 2019

CO2 7.1 7.9 8.5 8.0 8.1 7.4 7.8

Urea Fertilization 2.4 3.5 4.7 4.9 5.1 5.2 5.3

Liming 4.7 4.3 3.7 3.1 3.1 2.2 2.4

CH4 218.2 239.3 241.4 248.1 251.0 255.7 256.4

Enteric Fermentation 164.7 169.3 166.9 172.2 175.8 178.0 178.6

Manure Management 37.1 51.6 57.9 59.6 59.9 61.7 62.4

Rice Cultivation 16.0 18.0 16.2 15.8 14.9 15.6 15.1

Field Burning of Agricultural Residues 0.4 0.4 0.4 0.4 0.4 0.4 0.4

N2O 330.1 329.9 366.2 348.4 346.4 357.9 364.4

Agricultural Soil Management 315.9 313.4 348.5 330.1 327.6 338.2 344.6

Manure Management 14.0 16.4 17.5 18.1 18.7 19.4 19.6

Field Burning of Agricultural Residues 0.2 0.2 0.2 0.2 0.2 0.2 0.2

Total 555.3 577.1 616.1 604.4 605.5 621.0 628.6

Source: (US-EPA 2020c) 

Note the above figures do not fully account for carbon sequestration by crops, and soil management 

practices. Crop production systems can be both sources and sinks of GHGs, with the balance depending 

on a complex relationship of management practices, geographic region, and site-specific factors (e.g., 

weather conditions, soil type, proximity to surface and ground water bodies, topography). At the farm 

level, the following practices have overlapping and interacting effects on GHG emissions, particularly 

CO2 and N2O: tillage system, the timing of tillage and other field operations, residue management, crop 

selection and rotation, cover cropping practices, and the amount and timing of nutrient applications and 

other soil amendments. Cropland sources of CH4 emissions include rice cultivation and the burning of 

agricultural residues.

Isolated areas with high rates of C accumulation occur throughout the agricultural land base in the United 

States (US-EPA 2020c). In particular, higher rates of net C accumulation in mineral soils occur in the 

Corn Belt region, which is the region with the largest amounts of conservation tillage, along with 

moderate rates of Conservation Reserve Program (CRP) enrollment. The regions with the highest rates of 
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emissions from drainage of organic soils occur in the Southeastern Coastal Region (particularly Florida), 

upper Midwest and Northeast surrounding the Great Lakes, and isolated areas along the Pacific Coast 

(particularly California), which coincides with the largest concentrations of organic soils in the United 

States that are used for agricultural production (US-EPA 2020c). 

Calculation of GHG emissions from crops involves evaluation of the life cycle of an agricultural product 

starting from the processes of extracting raw materials, through crop production, to the use of crop 

products and waste management (Vermeulen et al. 2012). Life-cycle analysis (LCA) of emissions can be 

assessed using the carbon footprint (CF) method (Pandey et al. 2011; Holka and Bieńkowski 2020). In 

identifying the most significant sources of GHG emissions in the corn production process, LCA is a 

useful tool to work towards solutions aimed at reducing emissions in crop production. The total energy 

required to grow a crop (LCA) can be calculated by accounting for the energy associated with the inputs 

required for production. Energy and GHG emissions from agricultural inputs can be divided 

into primary (e.g., fuel for machinery operations), secondary (e.g., production and transportation of 

inputs), and tertiary (e.g., raw materials to produce items such as machinery and buildings) sources.

Holka and Bieńkowski (2020) performed LCAs and used life-cycle costing methodologies to assess the 

GHG emissions and costs associated with corn grain production in the stages from “cradle-to-farm gate”, 

i.e., through the processes of corn cultivation to grain harvesting (e.g., seed production, fertilizer and 

pesticide production and use). The calculated values of the carbon footprint indicator for corn production 

in conventional, reduced, and no-tillage systems were 2,347.4, 2,353.4, and 1,868.7 CO2 eq. ha−1, 

respectively. The largest source of GHG emissions was the use of nitrogen fertilizers. Non-inversion 

tillage with cover crops and leaving a large amount of crop residues in the field increased the 

sequestration of organic carbon and contributed to a significant reduction of the carbon footprint in maize 

production. The conventional tillage system demonstrated the highest overall life-cycle costs per 

hectare.(Holka and Bieńkowski 2020). These studies showed that the CF per functional unit of one ton of 

grain amounted to 184.8 kg CO2–eq. in CT, 189.8 kg CO2–eq. in RT and 178.0 kg CO2–eq. in NT. Other 

studies have found the CF value for corn ranges from 2440 to 4200 kg CO2–eq/ha (Camargo et al. 2013)- 

Including the sequestration of organic carbon (C) into the total LCA GHG emissions from corn 

production provides a net carbon footprint (CF net) value which was reduced compared to the baseline CF 

value by 42.9% in CT, 72.1% in RT, and 78.3% in NT (Holka and Bieńkowski 2020). Relating GHG 

emissions to the functional unit of one ton of corn grain shows that the inclusion of C sequestration 

contributes most effectively to lowering the total GHG emissions in NT and RT systems (by 78.3% and 

72.1%, respectively). Leaving large amounts of crop residues in the field contributed to the prevention of 

C losses and its sequestration. Moreover, the application of organic fertilizers also influenced the 

accumulation of C in the soil of the fields with CT and RT. The importance of the C sequestration process 

in reducing GHG emissions has been emphasized in the literature (Holka and Bieńkowski 2020). 

Among the analyzed technological operations in the grain maize production, the processes of mineral 

fertilization (from 36.7% in CT to 41.7% in RT), soil cultivation and sowing (from 31.2% in RT to 37.6% 

in CT) had the most significant share in shaping life-cycle costs. This resulted from the costs of mineral 

fertilizers, fuel, and machinery. Processes of harvesting and plant protection were of less importance 

(their shares were not higher than 17% in RT and 14% in CT) (Holka and Bieńkowski 2020). 
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The reduction of GHGs is a significant challenge for agriculture. There is a need to accurately identify the 

sources of emissions and to disseminate knowledge on agricultural practices that can contribute to 

reducing emissions in crop production (Holka and Bieńkowski 2020). The management of soil cultivation 

operations to increase the sequestration of organic carbon in the soil plays an important role in balancing 

GHG emission from agriculture (Holka and Bieńkowski 2020). The conducted research has shown that 

the use of no-tillage with a large amount of crop residues in the field significantly contributes to the 

reduction of GHG emissions in maize production. Regardless of the tillage system, the mineral 

fertilization process had the most potential impact on the GHG emission. Designing low-emission 

technologies requires considering the threats resulting particularly from the use of nitrogen fertilizers. To 

reduce emissions from fields and, at the same time, reduce the consumption of raw materials in fertilizer 

production, it is important to optimize fertilization (taking into account natural constraints, soil 

conditions) and the level of crop productivity (Holka and Bieńkowski 2020).

Farrell et al. (2006) compared six publications and found that the energy use and GHG emissions 

associated with corn (Zea mays L.) production ranged from 5728 to 12,066 MJ per ha per year and from 

2441 to 4201 kg CO2e per ha per year, respectively. One major factor causing variability in the results is 

the different energy and GHG emissions parameters used in the studies (Camargo et al. 2013). 

Across all crops, the largest contributor to the total amount of GHG emissions was N2O, which ranged 

from 157 kg CO2e per ha per year (17% of the total) in soybeans to 1539 kg CO2e per ha per year (45% of 

total) in corn silage. N production and on-farm fuel followed N2O emissions, representing 16% and 14%, 

respectively, across all crops. When it was averaged across crops, N2O emissions accounted for the 

greatest GHG contribution, with 44% of the total, followed by N production (16%), on-farm fuel (14%), 

lime (12%), K2O (4%), P2O5 (3%), transportation of inputs (3%), seed (2%), herbicide (1%), drying (1%), 

and insecticide (0.6%) (Camargo et al. 2013).

4.3.7.1 Potential Effects on Greenhouse Gas Emissions, and Effects of Climate Change on 

Corn Cropping Systems

DP23211 corn, and the agricultural inputs and management practices that would be used in cultivation of 

this variety would contribute to GHG emissions, and the potential for carbon sequestration, as do other

corn cropping systems. Any GHG emissions from cultivation of DP23211 corn would be the same 

as/similar to current crops emissions data (US-EPA 2020c). The agronomic practices and inputs are the 

same as for other corn varieties, and apart from the HR/IR traits, DP23211 corn is phenotypically the 

same as most other dent corn varieties—in growth and nutrient utilization requirements. 

GHG emissions directly impact the environment in which farmers operate, and agriculture stands to be 

significantly influenced by the effects of climate change (USDA 2012). Extremes in precipitation; more 

severe storms; soil moisture; nighttime air temperature; heat waves; humidity; drought spells; cropgrowing region migration; weed range and infestation intensity; migration and increased incidence in 

plant insect pests and pathogens; effects on insect generations per season; and effects on pollinators and 

pollinator management; are all factors that will be influenced by a changing, warming, climate, and in 

turn effect crop production (USDA 2012). 
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To help protect future crop production from, and adapt to, the effects of climate change the USDA 

contributes to climate assessments, provides analyses of adaptation and mitigation options, cost-benefit 

analyses, and tools to support agriculture, forests, grazing lands, and rural communities. The Climate 

Change Program Office (CCPO) operates within the Office of Energy and Environmental Policy (OEEP) 

to coordinate agricultural, rural, and forestry-related climate change program and policy issues across the 

USDA. The CCPO ensures that USDA is a source of objective, analytical assessments of the effects of 

climate change and proposed response strategies. 

In an effort to mitigate climate-related risks the USDA has established seven regional hubs for risk 

adaptation and mitigation to climate change (USDA 2020b). The USDA is taking steps to create modern 

solutions to the challenge of climate change. New uniform, science-based guidance on cover crop 

management helps producers prevent erosion, improve soil properties, supply nutrients to crops, suppress 

weeds, improve soil water content, and break pest cycles. The following are some of the USDA

assessments that project climate impacts, adaptive strategies, and mitigation opportunities/strategies: 

• Climate Change and Agriculture in the United States: Effects and Adaptation (USDA 2012) 

• Climate Indicators for Agriculture (Walsh et al. 2020) 

• Climate Change, Global Food Security, and the U.S. Food System (Brown et al. 2015) 

• Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, 

Volume II (USGCRP 2018) 

The USDA provides farmers guidance on tracking and mitigating GHG emissions. In 2014 the USDA 

released “Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale 

Inventory” (Eve et al. 2014). Through the development of this guidance, the USDA prepared two primary 

products: 1. A comprehensive review of techniques currently in use for estimating GHG emissions and 

removals from agricultural and forestry activities; and 2. A technical report outlining the preferred 

science‐based approach and specific methods for estimating GHG emissions at the farm or forest scale. 

The USDA also released a Carbon Management Evaluation Tool (COMET-FARM) to help producers

calculate how much carbon their land's soil and vegetation can remove from the atmosphere (USDA 

2020d). 

4.3.8 Compliance with Federal and State Laws and Regulations, Executive Orders, 

Policies, and Treaties 

4.3.8.1 Federal Laws and Regulations 

The laws most relevant to APHIS determinations of regulatory status are the National Environmental 

Policy Act of 1969 (NEPA), the Clean Water Act of 1972 (CWA), the Safe Drinking Water Act of 1974 

(SDWA), the Clean Air Act of 1970 (CAA), the Endangered Species Act of 1973 (ESA), and the National 

Historic Preservation Act of 1966 (NHPA). Compliance with the requirements of the ESA has been 

addressed in Appendix 1. Compliance with the requirements of NEPA, CWA, SDWA, CAA, and NHPA, 

are specifically addressed in the following subsections. 

4.3.8.1.1 National Environmental Policy Act (NEPA)

NEPA (42 United States Code (U.S.C) 4321, et seq.) is designed to ensure transparency and 

communication of the possible environmental effects of federal actions prior to implementation. The Act 

and implementing regulations require federal agencies to document, in advance and in detail, the potential 

effects of their actions on the human environment, so as to ensure that there is a full understanding of the 
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possible environmental outcomes of federal actions by both the decision-makers and the public. This EA

documents the potential environmental outcomes of the alternatives considered, approval or denial of 

Pioneer’s petition, consistent with the requirements of NEPA and Council on Environmental Quality 

implementing regulations at 40 CFR parts 1500–1508. 

4.3.8.1.2 Clean Air Act, Clean Water Act, and Safe Drinking Water Act

The CAA, CWA, and SDWA authorize the EPA to regulate air and water quality in the United States. As 

discussed in this EA, DP23211 corn production would entail the use of pesticides and fertilizers, and to 

some extent tillage. Because DP23211 corn is agronomically equivalent to currently utilized corn 

varieties, the potential impacts on water resources and air quality would be similar to that of other corn 

crops—both biotechnology-derived and conventionally bred corn cropping systems. APHIS assumes use 

of all pesticides on DP23211 corn will be compliant with EPA registration and label use requirements.

There are several federal, state, and private sector collaborative initiatives to help farmers alleviate the 

impacts of crop production on water resources and air quality, for example, the EPA Mississippi 

River/Gulf of Mexico Hypoxia Task Force (US-EPA 2020h) and USDA National Water Quality Initiative 

(NWQI) (USDA-NRCS 2019c). The USDA and EPA provide guidance for farmers on how to best 

manage agricultural emissions sources (USDA-EPA 2012). Considering these factors, it is unlikely 

approval of the petition would lead to circumstances that resulted in non-compliance of DP23211 corn

production with the requirements of the CAA, CWA, and SDWA. 

4.3.8.1.3 National Historic Preservation Act 

The NHPA of 1966 and its implementing regulations (36 CFR part 800) requires federal agencies to: 1) 

determine whether activities they propose constitute "undertakings" that have the potential to cause 

effects on historic properties and 2) if so, to evaluate the effects of such undertakings on such historic 

resources and consult with the Advisory Council on Historic Preservation (i.e., State Historic Preservation 

Office, Tribal Historic Preservation Officers), as appropriate. 

Approval of the petition is not a decision that would directly or indirectly result in alteration of the 

character or use of historic properties protected under the NHPA, nor would it result in any loss or 

destruction of cultural or historical resources. DP23211 corn would be cultivated on lands allocated or 

zoned for agricultural uses. As discussed in this EA, there are no weedy or invasive characteristics 

associated with DP23211 corn that could impact historic properties. 

4.3.8.2 Executive Orders

The following executive orders (EO) require consideration of the potential impacts of federal actions on 

human health, cultural resources, wildlife, and the environment. 

• EO 12898 – Federal Actions to Address Environmental Justice in Minority Populations and 

Low-Income Populations

The purpose of EO 12898 is to focus federal attention on the environmental and human health 

effects of federal actions on minority and low-income populations and Tribal nations with the goal 

of achieving environmental protection for all communities. EO 12898 directs federal agencies to: 

(1) identify and address the disproportionately high and adverse human health or environmental 

effects of their actions on minority and low-income populations, to the greatest extent practicable 

and permitted by law; (2) develop a strategy for implementing environmental justice (EJ); and (3) 
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promote nondiscrimination in federal programs that affect human health and the environment, as 

well as provide minority and low-income communities access to public information and public 

participation. 

• EO 13045 – Protection of Children from Environmental Health Risks and Safety Risks 

Children may suffer disproportionately from environmental health and safety risks due to their 

developmental stage, higher metabolic rates, and behavior patterns, as compared to adults. This EO

requires each federal agency to identify, assess, and address the potential environmental health and 

safety risks that may disproportionately affect children.

• EO 13175 – Consultation and Coordination with Indian Tribal Governments

Executive departments and agencies are charged with engaging in consultation and collaboration 

with tribal governments; strengthening the government-to-government relationship between the 

United States and Indian tribes; and reducing the imposition of unfunded mandates upon Indian 

tribes. The EO emphasizes and pledges that federal agencies will communicate and collaborate with 

tribal officials when proposed federal actions have potential tribal implications. 

• EO 13985 – Executive Order on Advancing Racial Equity and Support for Underserved 

Communities Through the Federal Government

This EO requires federal agencies to advance equity for all, including people of color and others 

who have been historically underserved, marginalized, and adversely affected by persistent poverty 

and inequality. Because advancing equity requires a systematic approach to embedding fairness in 

decision-making processes, executive departments and agencies are required to recognize and work 

to redress inequities in their policies and programs that serve as barriers to equal opportunity. 

Consistent with these aims, each agency must assess whether, and to what extent, its programs and 

policies perpetuate systemic barriers to opportunities and benefits for people of color and other 

underserved groups. Such assessments will better equip agencies to develop policies and programs 

that deliver resources and benefits equitably to all.

• EO 14091 – Further Advancing Racial Equity and Support for Underserved Communities 

Through the Federal Government 

This EO expands on EO 13895, and targets major barriers faced by underserved communities. It 

establishes mechanisms for advancing environmental justice and racial equity: A White House 

Steering Committee on Equity, Agency Equity Teams, and the requirement for an annual Equity 

Action Plan. 

• EO 14096 – Revitalizing Our Nation’s Commitment to Environmental Justice For All 

This EO builds on EO 12898 by expanding the definition of environmental justice, adding agency 

accountability measures, and emphasizing the role of the National Environmental Policy Act in 

evaluating EJ impacts. It requires federal agencies to create EJ strategic plans, directs research on 

EJ issues, expands notifications for toxic chemical releases, extends the membership of the EJ 

Interagency Council, and establishes the White House Office of Environmental Justice.
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Neither alternative evaluated in this EA is expected to have any disproportionate adverse impacts on 

minorities, low-income populations, or children, or adversely affect tribal entities. There are no 

challenges to establishing or maintaining equity for underserved communities identified with either 

alternative. As reviewed in this EA, there are no risks to human health, nor to food animal health and 

welfare, associated with the trait genes and gene products in DP23211 corn. DP23211 corn is 

compositionally and nutritionally comparable to other dent corn varieties. Tribal entities are recognized as 

independent governments and agricultural activities on tribal lands would only be conducted if approved 

by the tribe. Approval of the petition would have no effect on Indian tribal self-governance or 

sovereignty, tribal treaties, or other rights. APHIS conducted outreach to tribal nations informing tribes of

the Pioneer petition for DP23211 corn. APHIS received one reply from the Ysleta del Sur Pueblo Tribe, 

stating that this project will not adversely affect traditional, religious, or culturally significant sites.

• EO 13751 – Safeguarding the Nation from the Impacts of Invasive Species

Invasive species are a significant issue in the United States, causing both adverse economic and 

environmental impacts. This EO directs actions to continue coordinated federal prevention and 

control efforts related to invasive species. The order maintains the National Invasive Species 

Council (Council) and the Invasive Species Advisory Committee; expands the membership of the 

Council; clarifies the operations of the Council; incorporates considerations of human and 

environmental health, climate change, technological innovation, and other emerging priorities into 

federal efforts to address invasive species; and strengthens coordinated, cost-efficient federal 

action.

One concern with the cultivation of certain transgenic crops is their potential dispersal or spread into nonagricultural areas. Field corn (Zea mays) is a crop plant that was domesticated, bred for thousands of 

years, for large-scale food production. Domestication of Zea mays has rendered this cultivar less capable 

of survival in the wild, it is largely dependent on humans for persistence in the environment and not 

typically found outside areas of cultivation (OECD 2003). 

APHIS evaluated the potential weediness and invasiveness of DP23211 corn and concluded that it is 

unlikely that DP23211 corn will become weedy or invasive in areas where it is grown (USDA-APHIS 

2022b). As discussed in Section 4.3.3.4 – Gene Flow and Weediness of Corn, the potential for a weedy or 

invasive species of corn to develop as a result of outcrossing of DP23211 corn with other sexually 

compatible species of corn, or wild Tripsacum species, is negligible. As APHIS concluded in its PPRA, 

the introduced trait genes in DP23211 corn are not expected to alter characteristics associated with 

reproductive biology—change the ability of the plant to interbreed with other plant species (USDAAPHIS 2022b).

• EO 13186 – Responsibilities of Federal Agencies to Protect Migratory Birds

The United States has recognized the critical importance of migratory birds as a shared resource by 

ratifying international, bilateral conventions for the conservation of migratory birds. These 

conventions impose substantive obligations on the United States for the conservation of migratory 

birds and their habitats. Through the Migratory Bird Treaty Act (Act) the United States has 

implemented these conventions with respect to the United States. This Executive Order directs 

executive departments and agencies to take certain actions to further implement the Act.
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Migratory birds may transit corn fields and forage on corn, namely residual corn cobs/kernels left in the 

field post-harvest (Sherfy et al. 2011). For example, during migration, about 90% of the sandhill crane

diet consists of corn, when corn is available (NGP 2020). As reviewed in this EA, it is highly unlikely the 

DvSSJ1 dsRNA, and IPD072Aa, PAT, and PMI proteins present any risks to the health of birds. Thus, it 

is unlikely that approval of the petition, and subsequent production of DP23211 corn, would present any 

hazard to migratory bird populations that may transit DP23211 corn fields. Rather, DP23211 corn would 

likely provide a food source for some species of migratory birds. 

4.3.8.3 State and Local Requirements

The PPA contains a preemption clause (7 U.S.C. § 7756) that prohibits state regulation of any “plant, 

biological control organism, plant pest, noxious weed, or plant product” to protect against plant pests or 

noxious weeds if the Secretary (USDA) has issued regulations to prevent the dissemination of biological 

control organisms, plant pests, or noxious weeds within the United States. The PPA preemption clause 

does however allow states to impose additional prohibitions or restrictions based on special needs 

supported by sound scientific data or risk assessment. Consequently, while the PPA limits states' issuance 

of laws and regulations governing regulated organisms and bars conflicting state regulation, it does allow 

state oversight when there is a special need for additional prohibitions or restrictions. 

States use a variety of mechanisms to regulate the movement or release of biotechnology-derived crops

within their jurisdiction. For example, South Dakota simply authorizes holders of a federal permit issued 

under 7 CFR part 340 to use it within the state (SD Stat § 38-12A-31 (2015)). Minnesota issues state 

permits for release of biotechnology-derived organisms only after federal applications or permits are on 

file (MN Stat § 18F.07 (2015)). Nebraska may rely on APHIS or other experts before they issue their 

permit (NE Code § 2-10,113 (2015)). These illustrative examples show the range of state approaches to 

regulating the movement and release of biotechnology-derived crops within state boundaries.

Neither of the alternatives considered would affect APHIS partnerships with states in the oversight of 

biotechnology-derived crops, specifically in the regulation of environmental releases. Under both 

alternatives, APHIS would continue working with states. The range of state legislation addressing 

agricultural biotechnology, namely in the way of permitting, crop protection, seed regulation, and 

economic development, would be unaffected by denial or approval of the petition.

4.3.9 Conclusions: Potential Impacts on the Human Environment

As discussed in the Scope of Analysis for this EA (Section 4.1), in considering whether the effects of the 

proposed action could be significant APHIS analyzed the affected environment and degree of the 

potential effects identified (40 CFR § 1501.3). As part of this analysis APHIS considered those 

requirements outlined in sections 102(2)(C) of NEPA, 40 CFR § 1502.16–Environmental consequences, 

40 CFR § 1501.3–Determine the appropriate level of NEPA review, 40 CFR § 1502.24–Environmental 

review and consultation requirements, and 40 CFR § 1502.15–Affected environment, which are addressed 

below. APHIS has not identified any significant impacts on the human environmental that would derive 

from approval nor denial of the petition. 
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4.3.9.1 Potential adverse environmental effects that cannot be avoided should the proposal 

be implemented

Commercial crop production, whether a conventional, organic, or biotechnology-based cropping system 

will always has some degree of environmental impact (Robertson and Swinton 2005; NRC-IM 2015; 

Ritchie 2017). The potential introduction of pesticides and fertilizers to surface water or groundwater, soil 

erosion, fossil fuel use and emission of air pollutants, and effects on wildlife habitat and biodiversity are 

issues that all farmers, and the agricultural sector at large, work with in providing sufficient food, feed, 

fiber, fuel, and industrial products to meet societal needs. The degree of environmental impacts can be 

minor or noticeably adverse depending on a variety of factors that include the type and quantity of 

chemical/fertilizer inputs utilized; tillage practices; prevalence and diversity of crop insect pests and 

weeds; the efficacy of nutrient, insect pest, disease, and weed management programs; geography and 

proximity of surface waters and groundwater to crops; local biota; weather; and cover cropping and crop 

rotation practices. With around 360,000 corn farms utilizing around 90 million acres of the land in the 

United States (USDA-NASS 2019a), the scale of potential impacts, namely in an aggregate sense, 

necessitates integration of crop production with sustainability and conservation practices—for 

biotechnology-derived, conventionally bred, and organic crops alike. Implementing such practices can 

often result in significant mitigation of environmental impacts, however, not all impacts can be fully 

attenuated and accepting some degree of environmental impact/change in meeting the market demand for 

corn-based food, feed, fuel, and industrial commodities is inevitable (Robertson and Swinton 2005; NRCIM 2015).

On approval of the petition, and subsequent grower adoption of DP23211 corn, the agronomic practices 

and inputs that would be used in the cultivation of DP23211 corn, and any contribution of these practices 

and inputs to impacts on soils, water quality, or air quality, as well as biological resources, would be 

similar to that of other corn crops currently cultivated. APHIS did not identify any significant changes to 

agronomic practices and inputs, nor in DP23211 corn physiology that would have effects on plant 

diseases and insect pests or their management. It is expected that DP23211 corn would be produced on 

lands already converted to cropland—replace other HR/IR corn crops currently cultivated. Hence, 

adoption of DP23211 corn is not expected to have any effect on wildlife habitats or biodiversity.

There are various federal, state, and private sector collaborative initiatives that support sustainable 

agricultural practices to help alleviate the collective impacts of crop production on the physical 

environment, as well as biological resources—some of which are summarized below in Section 4.3.9.9.

4.3.9.2 The relationship between short-term uses of man’s environment and the maintenance 

and enhancement of long-term productivity

Long-term agricultural productivity depends on the sustainable utilization of natural resources over 

continued production cycles—namely topsoil, groundwater, beneficial insect populations such as plant 

pest predators and pollinators, the plants that support beneficial insects, and products such as pesticides 

and fertilizers that derive from natural resources. DP23211 corn is agronomically equivalent to other dent 

corn cultivars and would utilize the same types, and same/similar quantities of resources (e.g., 

groundwater, pesticides, fertilizers), as all other conventional and biotechnology-derived dent corn 

varieties. The annual production of DP23211 corn would face the same challenges in sustaining top-soils 

and soil quality, and air and water quality, as other corn crops. Any groundwater use is expected to be 
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similar to that of other dent corn varieties—there is no indication this variety utilizes more or less water 

during development. 

There could be, to some extent, reductions in insecticide and fossil fuel use with this corn variety—the 

utilization of the natural resources from which insecticides and fuels are derived. As a PIP based IR corn 

variety targeting Diabrotica virgifera virgifera, there would be a potential reduction in hazards to

pollinators, and beneficial predator and parasitoid species (Bale et al. 2008; Barratt et al. 2018). This 

would be relative to how this IR corn variety facilitated reductions in, or limited use of, broad spectrum 

chemical insecticides, and the particular insecticides used (e.g., neonicotinoids, pyrethroids, or 

organophosphates). The novel RNAi (DvSSJ1 dsRNA) and IPD072Aa MOAs could facilitate 

management of development of insect resistance by broadening the variety of PIP MOAs in crops. These 

aspects of DP23211 corn would be expected to be of potential benefit to sustaining the long-term 

productivity of U.S. corn cropping systems, in association with the efficacy of implemented IWM and 

IPM programs. 

4.3.9.3 Irreversible or irretrievable commitments of resources that would be involved in the 

proposal should it be implemented

An irreversible or irretrievable commitment of resources refers to impacts on or losses of resources that 

cannot be recovered or reversed. Irreversible commitments of resources involve those where the resources 

cannot be restored or returned to their original condition, such as the use of nonrenewable fossil fuel

based products, and resources that are renewable only over long time spans. Irretrievable is a term that

refers to those resources that, once used or utilized, would cause the resource to be unavailable for use by 

others or future generations (e.g., land use).

The production of corn and the food, feed, fuel, and industrial products derived from corn involves the

irreversible and irretrievable utilization of resources. For example, corn production involves the 

irreversible consumption of nonrenewable petroleum-based products (e.g., fuels necessary to operate 

equipment, cleaning agents, pesticide additives/adjuvants). Crude oil cannot be replaced once utilized for 

energy or other purposes. Some crop production systems may utilize wind or solar energy sources—

renewable sources. Topsoil is considered nonrenewable, its erosional capacity can be affected by the 

types of tillage and irrigation systems employed on cropland. Over the long-term continued crop 

production on the same site can potentially contribute to wind and water erosion; cover cropping can help 

preserve and rebuild topsoil. Materials such as aluminum, steel, wood, and plastics would be utilized as 

part of the process of crop production. Most of these materials are non-renewable and would be 

irreversibly utilized if not recycled (plastics, metals). Crop production inherently entails the irretrievable 

removal of natural habitat and associated wildlife from the landscape; the relocation of associated wildlife 

to other landscapes.

DP23211 corn would be used to supply standard corn-based feed, fuel, food, and industrial commodities, 

and is physiologically and agronomically equivalent to other dent corn varieties (Pioneer 2020). Any 

irreversible or irretrievable commitments of resources in the production of DP23211 corn, and marketing 

of DP23211 corn commodities, would be similar to that of other dent corn cropping systems. As an IR 

crop variety utilizing PIPs, reductions in fossil fuel use could occur in production of the crop, relative to 

conventionally bred non-IR corn varieties on which pesticides are sprayed. Fossil fuels are commonly 

used in the manufacture, transportation, and application of insecticides to commercial corn crops.
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4.3.9.4 Whether the action would violate or conflict with a federal or state laws or local 

requirements governing protection of the environment and environmental justice

Based on the data reviewed in this EA, approval of the petition would not lead to circumstances that 

resulted in non-compliance with any federal or state laws, local ordinances, or Executive Orders 

providing protections for the environment, public health, underserved communities, or minority or low 

income populations. The EPA regulates the use of pesticides on DP23211 corn. Pioneer completed a food 

safety consultation with the FDA in 2022; based on the information Pioneer presented to the FDA, the 

FDA had no further questions concerning the safety of human or animal food derived from DP23211 

corn, noting that it is Pioneer’s continuing responsibility to ensure that foods marketed by the firm are 

safe, wholesome, and in compliance with all applicable legal and regulatory requirements (US-FDA 

2022).

4.3.9.5 Possible conflicts between the proposed action and the objectives of federal, regional, 

state, tribal, and local land use plans, policies, and controls for the area concerned

There would be no conflicts with approval of the petition, and subsequent commercial production and 

marketing of DP23211 corn, with federal, state, tribal, or local land use plans or policies. 

Federal Lands

There are four major federal land management agencies that administer around 606.5 million acres (as of 

September 30, 2018). These are the Bureau of Land Management (BLM), Fish and Wildlife Service 

(FWS), National Park Service (NPS) in the Department of the Interior (DOI), and the Forest Service (FS) 

in the USDA. A fifth agency, the Department of Defense (DoD), administers 8.8 million acres in the 

United States (as of September 30, 2017). Together, the five agencies manage about 615.3 million acres, 

or 27% of the U.S. land base (CRS 2020). Many other agencies administer the remaining federal acreage. 

The lands administered by the four major agencies are managed primarily for purposes related to 

preservation, recreation, and development of natural resources (CRS 2020).

APHIS approval of the petition would have no effect on lands governed by federal land management 

agencies, nor federal oversight of these lands. Any cultivation of DP23211 corn on federal lands would 

require approval by a federal land management agency. 

Tribal Nations, State, and Local Land Use Plans and Policies

As reviewed in Section 4.3.8–Compliance with Federal and State Laws and Regulations, Executive 

Orders, Policies, and Treaties, approval nor denial of the petition would have any effect on Indian tribal 

self-governance or sovereignty, tribal treaties, or other rights, nor affect state or local authority in the 

oversight of biotechnology-derived crops, to include the production of DP23211 corn on state, county 

lands, or other governed lands. 

4.3.9.6 Energy requirements and conservation potential of various alternatives and mitigation 

measures 

DP23211 corn is agronomically equivalent to other corn varieties—the energy requirements involved 

with the full life cycle of DP23211 corn production and marketing would differ little from that of other 

commercial corn crops. USDA-NRCS provides guidance on energy management in crop production via 

practices such as integrated pest management, precision agriculture, irrigation water and nutrient 

management, and crop residue management (USDA-NRCS 2020b). Energy conservation estimation tools 
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are also provided to help growers estimate costs and saving associated with irrigation, nitrogen use, and 

tillage.

4.3.9.7 Natural or depletable resource requirements and conservation potential of various 

alternatives and mitigation measures

There are no depletable resource requirements unique to the production and marketing of DP23211 corn. 

Use of natural resources (e.g., irrigation water, land/soils, production or herbicides and fertilizers) would 

be no different than that of other corn varieties. Natural resource conservation opportunities, whether 

USDA funded or otherwise implemented by growers or/and state agencies would not differ from that of 

other conventional and biotechnology-derived corn crops. Available resources to help mitigate potential 

environmental impacts, such as those summarized below in 4.3.9.9, would likewise not differ. 

4.3.9.8 Urban quality, historic and cultural resources, and the design of the built environment, 

including the reuse and conservation potential of various alternatives and mitigation 

measures

As reviewed in 4.3.3.4–Gene Flow and Potential Weediness of DP23211 Corn, there are no weedy or 

invasive characteristics associated with DP23211 corn that could impact historic properties—result in 

alteration of the character or use of historic properties protected under the NHPA. The design of the built 

environment in relation to crop production activities would be resolved at the state and local levels of 

governance (e.g., city, county, and/or state authorities governing land use).

4.3.9.9 Means to mitigate adverse environmental impacts

There are a number of federal, state, and private sector collaborative initiatives to help farmers alleviate 

the collective impacts of crop production on the physical environment, as well as biological resources. 

Some of the USDA and partner programs supporting agricultural sustainability and natural resources 

conservation are summarized below. Practices will vary from region to region and farm to farm, however, 

some common sets of practices have emerged, which include integrated insect pest and weed 

management, soil conservation tactics, water resources conservation and water quality protection, 

conservation of cropland biodiversity, and nutrient management. Each contribute in some way to 

environmental stewardship and long-term farm sustainability. A more detailed description of USDA 

sustainability and conservation initiatives are provided in the references below.

The EPA Mississippi River/Gulf of Mexico Hypoxia Task Force (US-EPA 2020h) and USDA Natural 

Resources Conservation Service (NRCS) National Water Quality Initiative (NWQI) (USDA-NRCS 

2019c) aim to reduce NPS contaminants in agricultural run-off, and run-off itself. The purpose of the 

NWQI, in collaboration with the EPA and state water quality agencies, is to reduce nonpoint sources of 

nutrients, sediment, and pathogens related to agriculture in high-priority watersheds in each state.

The USDA Climate Change Program Office (CCPO) operates within the Office of Energy and 

Environmental Policy (OEEP) to coordinate agricultural, rural, and forestry-related climate change 

program and policy issues across USDA. OEEP's CCPO works across USDA to help ensure that the 

effects of climate change on working lands and rural communities are understood across the Department 

and that adaptation is integrated into USDA programs, policies and operations based on the most up-todate science. OCE also provides data, tools and information to assist land managers, stakeholders and 

USDA agencies and mission areas with adaptation assessments, planning and implementation (USDA 

2020c).
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The USDA funded Sustainable Agriculture Research and Education Program (SARE) supports

sustainable agricultural practices that are intended to protect the environment, conserve natural resources, 

and promote cropland biodiversity (USDA-NIFA 2020). 

The USDA-NRCS's Natural Resources Conservation Programs help people reduce soil erosion, enhance 

water supplies, improve water quality, increase wildlife habitat, and reduce damages caused by floods and 

other natural disasters (USDA-NRCS 2019a). 

The USDA-NRCS Environmental Quality Incentives Program (EQIP) provides financial and technical 

assistance to agricultural producers to address natural resource concerns and deliver environmental 

benefits such as improved water and air quality, conserved ground and surface water, increased soil health 

and reduced soil erosion and sedimentation, improved or created wildlife habitat, and mitigation against 

increasing weather volatility (USDA-NRCS 2020a).

The USDA–NRCS Regional Conservation Partnership Program (RCPP) specifically promotes 

coordination of NRCS conservation activities with partners that offer value-added contributions to expand 

USDA’s collective ability to address on-farm, watershed, and regional natural resource concerns (USDANRCS 2020c). The 2018 Farm Bill made a number of substantial changes to RCPP: It is now a standalone 

program with its own funding of $300 million annually.

The USDA National Institute of Food and Agriculture (NIFA) promotes sustainable agriculture through 

national program leadership and funding for research and extension. It offers competitive grants programs 

and a professional development program, and it collaborates with other federal agencies through the 

USDA Sustainable Development Council (USDA-NIFA 2020). 

The USDA Conservation Reserve Program (CRP) is a voluntary land retirement program that provides

financial compensation to landowners to remove highly erodible and environmentally sensitive land from 

agricultural production and install resource-conserving practices or preserve wildlife habitat. CRP is the 

largest federally administered private-land retirement program, with annual outlays approaching $2 

billion per fiscal year. CRP enrollment is capped each year, and under the 2014 farm bill, enrollment was 

limited to no more than 24 million acres during fiscal years 2017 and 2018. The 2018 farm bill expanded

CRP acreage to a maximum of 27 million acres by 2023. Nearly 24 million acres are enrolled in CRP as 

of 2019 (NSAC 2020).

4.3.9.10 Economic and technical considerations, including the economic benefits of the 

proposed action

Economic considerations have been evaluated in Section 4.3.6 – Socioeconomics. The economic impacts 

associated with the utilization of DP23211 corn for production of food, feed, fuel, and industrial 

commodities could be potentially beneficial, to both farmers and corn commodities markets.

4.3.9.11 The degree to which the action may adversely affect endangered or threatened 

species protected under the Endangered Species Act of 1973

Based on APHIS’ evaluation provided in Appendix 1 of this EA, a determination of nonregulated status 

of DP23211 corn, and subsequent commercial production of this corn variety, would have no effect on 

listed species or species proposed for listing, nor would it affect designated habitat or habitat proposed for 

designation. 
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4.3.9.12 The degree to which the proposed action affects public health or safety

As reviewed in Section 4.3.4 – Human Health, approval of the petition and subsequent availability of 

DP23211 to commercial markets would not present any risks to public health or worker safety.

4.3.9.13 Whether the affected environment includes reasonably foreseeable environmental 

trends and planned actions in the affected areas

Approval of the petition would provide for the commercial production of DP23211 corn, subject to any 

FDA, EPA, state, or tribal requirements. APHIS maintains a publicly available list of petitions and 

determinations of nonregulated status on its website (USDA-APHIS 2022a). Insect and herbicide resistant 

varieties of corn were first deregulated in 1995, with adoption rates increasing rapidly in the years that 

followed. As of May 2023, APHIS has issued determinations of nonregulated status in response to 41

petitions for biotechnology-derived corn varieties. Currently, over 90% of U.S. corn acreage is comprised 

of biotechnology-derived varieties (USDA-ERS 2022b).

Farmers generally adopt a biotechnology-derived crop based on the benefits they can derive from it, such 

as effective insect pest or/and weed control, maximal crop yields per acre, increased farm net returns, and 

time savings (Fernandez-Cornejo et al. 2014b; Brookes and Barfoot 2018b). Potential net benefits are a 

function of the particular crop farmed and geographic location; pest and weed pressures; agronomic input 

and market commodity prices; and efficacy of on-farm crop production practices (e.g., IWM, IRM). 

Advances in agricultural biotechnology are expected to continue, and refine the precision with which crop 

varieties will be developed, leading to a greater diversity of commercial crop varieties (NAS 2016). While 

it is difficult to predict the scope of improved crop varieties that will emerge in the coming years, traits 

likely to be introduced and adopted by growers include improved tolerance to abiotic stresses such as 

drought and temperature extremes; increased efficiency in plant physiological processes such as 

photosynthesis and nitrogen use; resistance to fungal, bacterial, and viral diseases; and new types of

herbicide resistance (NAS 2016).

For those biotechnology-derived plants that APHIS has determined are not subject to 7 CFR part 340, 

which were evaluated for potential plant pest risks, and potential environmental impacts via NEPA 

analyses: The available science provides little evidence that the cultivation of the presently 

commercialized biotechnology-derived corn plants have resulted in any adverse environmental impacts 

that are unique, or differ from conventional crops and cropping systems (e.g., (Sanvido et al. 2007; 

Klümper and Qaim 2014; Brookes and Barfoot 2018b; Brookes and Barfoot 2020), and others).

Generally, to date, biotechnology-derived crops, which undergo evaluation by USDA, the EPA, and FDA 

under the Coordinated Framework (ETIPCC 2017; USDA-APHIS 2020b), have been found to have no 

more or fewer adverse effects on the environment than conventionally bred crops (NRC 2010; NAS 2016; 

Brookes and Barfoot 2020).

.
A1-1

APPENDIX 1: THREATENED AND ENDANGERED SPECIES

The Endangered Species Act (ESA) of 1973, as amended, is one of the most far-reaching wildlife 

conservation laws ever enacted by any nation. Congress passed the ESA to prevent extinctions facing 

many species of fish, wildlife, and plants. The purpose of the ESA is to conserve threatened and

endangered and species and the ecosystems on which they depend as key components of America’s 

heritage. To implement the ESA, the U.S. Fish & Wildlife Service (USFWS) works in cooperation with 

the National Marine Fisheries Service (NMFS), other federal, state, and local agencies, tribes, nongovernmental organizations, and private citizens. Before a plant or animal species can receive the 

protection provided by the ESA, it must first be added to the federal list of threatened and endangered 

wildlife and plants.

A species is added to the list when it is determined by the USFWS/NMFS to be threatened or endangered

because of any of the following factors:

• The present or threatened destruction, modification, or curtailment of its habitat or range;

• Overutilization for commercial, recreational, scientific, or educational purposes;

• Disease or predation;

• The inadequacy of existing regulatory mechanisms; and

• The natural or manmade factors affecting its survival.

Once an animal or plant is added to the list, in accordance with the ESA, protective measures apply to the 

species and its habitat. These measures include protection from adverse effects of federal activities. 

1 Requirements for Federal Agencies

Section 7(a)(2) of the ESA requires that federal agencies, in consultation with USFWS and/or the NMFS, 

ensure that any action they authorize, fund, or carry out is “not likely to jeopardize the continued 

existence of a listed species or result in the destruction or adverse modification of designated critical 

habitat.” It is the responsibility of the federal agency taking the action to assess the effects of their action 

and to consult with the USFWS and NMFS if it is determined that the action “may affect” listed species 

or designated critical habitat (a process is known as a Section 7 Consultation). 

To facilitate the development of its ESA consultation requirements, APHIS met with the USFWS from 

1999 to 2003 to discuss factors relevant to APHIS’ regulatory authority and effects analysis for petitions 

for nonregulated status of biotechnology-derived crop lines. By working with USFWS, APHIS developed 

a process for conducting an effects determination consistent with the Plant Protection Act (PPA) of 2000

(Title IV of Public Law 106-224). APHIS uses this process to help fulfill its obligations and 

responsibilities under Section 7 of the ESA for regulatory actions. 

APHIS regulatory authority under the PPA is limited to those organisms that could pose a plant pest risk, 

or where APHIS does not have sufficient information to determine that the organism is unlikely to pose a

plant pest risk. After completing a PPRA, if APHIS determines that DP23211 corn seeds, plants, or parts 

thereof do not pose a plant pest risk, then this DP23211 corn would no longer be subject to the plant pest 

provisions of the PPA or to the regulatory requirements of 7 CFR part 340, and therefore, APHIS must 

reach a determination that DP23211 corn is not subject regulation. As part of this EA, APHIS analyzed
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the potential effects of DP23211 corn on TES and critical habitat. APHIS thoroughly reviewed data 

related to DP23211 corn to inform the ESA effects analysis. For each transgene the following 

information, data, and questions are considered by APHIS: 

• A review of the biology, taxonomy, and weediness potential of the crop plant and its sexually 

compatible relatives;

• Characterization of each transgene with respect to its structure and function and the nature of the 

organism from which it was obtained;

• A determination of where the new transgene and its products (if any) are produced in the plant 

and their quantity;

• A review of the agronomic performance of the plant including disease and pest susceptibilities, 

weediness potential, and agronomic and environmental impact;

• Determination of the concentrations of known plant toxicants (if any are known in the plant); and

• Analysis to determine if the transgenic plant is sexually compatible with any threatened or 

endangered plant species (TES) or a host of any TES.

• Any other information that may inform the potential for an organism to pose a plant pest risk.

APHIS met with USFWS officials on June 15, 2011, to discuss and clarify whether APHIS has any 

obligations under the ESA regarding analyzing the effects on TES that may occur from use of pesticides 

associated with biotechnology-derived crops. As a result of these joint discussions, USFWS and APHIS

have agreed that it is not necessary for APHIS to perform an ESA effects analysis on pesticide use 

associated with biotechnology-derived crops because the EPA has both regulatory authority over the 

labeling of pesticides under FIFRA, and the necessary technical expertise to assess pesticide effects on the 

environment. APHIS has no statutory authority to authorize or regulate the use of pesticides by corn

growers. Under the PPA and APHIS’ 7 CFR part 340 regulations, APHIS only has the authority to 

regulate DP23211 corn and other organism developed using genetic engineering as long as APHIS

believes they may pose a plant pest risk. APHIS has no regulatory jurisdiction over any other risks 

associated with organisms developed using genetic engineering, including risks resulting from the use of 

pesticides on those organisms.

Relative to herbicide use with DP23211 corn, the EPA issues Endangered Species Protection Bulletins as

part of the EPA's Endangered Species Protection Program, and pesticide use requirements. Bulletins set 

forth geographically specific pesticide use limitations for the protection of threatened and endangered 

(listed) species and their designated critical habitat. These bulletins contain enforceable pesticide use 

limitations that are necessary to ensure a pesticide's use will not harm a species listed as threatened or 

endangered under the Endangered Species Act, or their designated critical habitat (US-EPA 2021). 

2 Potential Effects of DP23211 Corn on TES

Based on the information submitted by Pioneer and reviewed by APHIS, DP23211 corn, with the 

exception of insect resistance and resistance to glufosinate-ammonium, is agronomically and 

compositionally comparable to conventional corn (Pioneer 2020). Pioneer has presented results of 

agronomic field trials for DP23211 corn. The results of these field trials demonstrate that there are no 

differences in agronomic practices between DP23211 corn and conventional corn, apart from the specific 

use of use of glufosinate-ammonium, and potential reduction in chemical insecticide use. The common 
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agricultural practices that would be carried out in the cultivation of DP23211 corn are not expected to 

deviate from current practices. DP23211 corn is not expected to directly cause a change in U.S. corn

acreage or the areas devoted to corn production (see Subsection 4.3.1—U.S. Corn Production). It is 

expected that DP23211 corn will replace other varieties of HR/IR corn without expanding the acreage or 

area of corn production.

Corn can be grown in all 50 states and U.S. territories. The issues discussed herein focus on the potential 

environmental consequences of approving the request for nonregulated status of DP23211 corn on TES 

and critical habitat in the areas where corn is currently cultivated. APHIS obtained and reviewed the 

USFWS list of TES species (listed and proposed) for all 50 states and U.S. territories where corn is 

produced from the USFWS Environmental Conservation Online System (USFWS 2021). 

For its analysis on TES plants and critical habitat, APHIS focused on the agronomic differences between 

DP23211 corn and corn varieties currently grown; the potential for increased weediness; and the potential 

for gene movement to native plants, listed species, and species proposed for listing. 

For its analysis of effects on TES animals, APHIS focused on the implications of exposure to the DvSSJ1 

dsRNA, and IPD072Aa, PAT, and PMI proteins expressed in DP23211 corn, and the ability of the plants 

to serve as a host for a TES.

2.1 Threatened and Endangered Plant Species and Critical Habitat

The agronomic data provided by Pioneer were used in the APHIS analysis of the weediness potential for 

DP23211 corn and evaluated for the potential to impact TES and critical habitat. Agronomic studies 

conducted by Pioneer evaluated the weediness and invasiveness potential of DP23211 corn with respect 

to conventional corn (Pioneer 2020). The results obtained from these studies demonstrated that the 

agronomic characteristics of DP23211 corn were comparable to those of conventional corn. Statistically 

significant differences were identified in days to flowering and final population, with 39 of 47 

observations for days to flowering and 46 of 47 observations for final population within the reference 

range. These differences are not anticipated to be biologically meaningful as they are within the normal 

ranges of variation in conventionally bred corn varieties. The differences observed for days to flowering 

and final stand count are unlikely to result in DP23211 corn with increased weediness potential or 

survivability, compared to conventional corn, which is not considered a weedy or invasive plant. As 

discussed in this EA and APHIS’ PPRA (USDA-APHIS 2022b), there are no weed risks associated with 

DP23211 corn. Volunteer corn plants can be easily controlled with herbicides or mechanical means if 

needed. 

APHIS evaluated the potential of DP23211 corn to cross with a listed species. There are no federally 

listed Zea or Tripsacum species in the United States (USFWS 2021), genera with which corn (Zea mays) 

may interbreed. As discussed in Gene Flow and Weediness (Section 4.3.3.4), the potential for gene 

movement between DP23211 corn and related teosinte (Zea) species is limited. Teosinte do not appear to 

be present in the United States other than in botanical gardens or at research stations. Three species of 

Tripsacum have been identified in the United States: Eastern gamagrass, Mexican gamagrass, and Florida 

gamagrass. Eastern gamagrass is the only Tripsacum species of widespread occurrence (USDA-NRCS 

2002). The potential for hybridization and successful introgression of Z. mays genes into Tripsacum

populations is, however, rare (de Wet and Harlan 1972; de Wet et al. 1978; Eubanks 1995). Special 
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techniques are required to hybridize Z. mays and Tripsacum; hybrids of Tripsacum species with Zea

species do not commonly occur outside of a laboratory. Based on these factors, APHIS determined that 

DP23211 corn will have no effect on threatened or endangered plant species or on critical habitat in the 

United States.

2.2 Threatened and Endangered Animal Species 

Threatened and endangered animal species that may be exposed to the gene products from DP23211 corn 

would be those TES that inhabit corn fields and feed on DP23211 corn. As discussed in Section 4.3.3–

Biological Resources, cornfields are generally considered poor habitat for birds and mammals in 

comparison with uncultivated lands, although the use of cornfields by birds and mammals is not 

uncommon. Some birds and mammals use cornfields at various times throughout the corn production 

cycle for feeding, cover, or roosting. Most birds and mammals that utilize cornfields are ground foraging 

omnivores that feed on corn seed, sprouting corn, and the corn remaining in the fields following harvest. 

Of the TES birds, whooping crane (Grus americana), Mississippi sandhill crane (Grus canadensis pulla), 

piping plover (Charadrius melodus), and interior least tern (Sterna antillarum) may transit and feed in 

corn fields during migration (Krapu et al. 2004; Sherfy et al. 2011; USFWS 2011). The whooping crane,

in particular, is known to forge in, and roost near, agricultural fields during migration (CWS-USFWS 

2007). About 90% of the sandhill crane diet consists of corn, when corn is available (NGP 2020). 

As discussed in Section 4.3.3.2–Animal Communities, many mammals may feed on corn, particularly 

white-tailed deer, raccoons, mice, and voles. There are no listed raccoon species in the United States. 

There are two listed deer species in the United States. Key deer (Odocoileus virginianus clavium) are 

highly localized in the Florida Keys (USFWS 2021). Listed populations of Columbian white-tailed deer 

(Odocoileus virginianus leucurus) are found in certain areas associated with the Columbia River in 

Washington State (USFWS 2021). These locations are well south and west, respectively, of the regions 

where corn crops are typically planted (Section 4.3.1.1–Acreage and Area of U.S. Corn Production). Of 

the mice, voles, and their relatives in the Cricetidae family, listed species include: the Amargosa vole 

(Microtus californicus scirpensis), which is listed as endangered and occurs in California (USFWS 2021);

the Florida salt marsh vole (Microtus pennsylvanicus dukecampbelli), which occurs in salt marsh habitat 

on the Gulf Coast of Florida (USFWS 2021); the endangered Key Largo woodrat (Neotoma floridana 

smalli) of Florida Key’s climax hardwood hammocks (USFWS 2021); and the northern and southern 

subspecies of the endangered, tidal marsh dwelling, salt marsh harvest mouse (Reithrodontomys 

raviventris) (USFWS 2013, 2021).

APHIS considered the risks to threatened and endangered animals from consuming DP23211 corn. 

Pioneer presented information on the food and feed safety of DP23211 corn, comparing the DP23211

corn variety with conventional varieties currently grown. There are no toxins or allergens associated with 

this plant (Pioneer 2020). The forage assessment included proximate, fiber, and mineral analytes. The 

grain assessment included proximate, fiber, fatty acid, amino acid, mineral, vitamin, secondary 

metabolite, and anti-nutrient analytes. The analytes included for the compositional assessment were based 

on the OECD consensus document on compositional considerations for new varieties of corn (OECD 

2003). Results presented by Pioneer show that the introduced genetic material in DP23211 corn does not 

result in any significant compositional differences between DP23211 corn and non-transgenic corn. 
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As discussed in those sections addressing human health, animal health and welfare, and wildlife; there are 

no health hazards associated with the DvSSJ1 dsRNA, and IPD072Aa, PAT, and PMI proteins. 

Therefore, there is no expectation that exposure to the DvSSJ1 dsRNA, and IPD072Aa, PAT, and PMI 

proteins will have any effect on TES that may consume DP23211 corn. As part of the FDA voluntary 

biotechnology consultation program, Pioneer completed a food/feed safety consultation with the FDA in 

2022. Based on the information Pioneer presented to the FDA, the FDA had no further questions 

concerning the safety of human or animal food derived from DP23211 corn, noting that it is Pioneer’s 

continuing responsibility to ensure that foods marketed by the firm are safe, wholesome, and in 

compliance with all applicable legal and regulatory requirements (US-FDA 2022).

APHIS considered the possibility that DP23211 corn could serve as a host plant for a threatened or 

endangered species (i.e., a listed insect or other organism that may use the corn plant to complete its 

lifecycle). APHIS is not aware of any TES for which corn serves as a host plant (USFWS 2021).

Considering the compositional similarity between DP23211 corn and other corn varieties currently 

grown, and the lack of any hazard presented by the introduced IR and HR trait genes and gene products, 

apart from targeted lethality for the plant pest Diabrotica virgifera virgifera, APHIS has concluded that 

exposure to and consumption of DP23211 corn would have no effect on threatened or endangered animal 

species.

3 Summary

After reviewing the possible effects of a determination of nonregulated status, and subsequent commercial 

production of DP23211 corn, APHIS has not identified any stressor that could affect listed TES or species 

proposed for listing. APHIS also considered the potential effect of DP23211 corn on designated critical 

habitat and habitat proposed for designation, and could identify no differences from effects that would 

occur from the production of other corn varieties. Corn is not sexually compatible with, nor serves as a 

host species for, any listed species or species proposed for listing. Consumption of DP23211 corn by any 

listed species or species proposed for listing would pose no health risks. DP23211 corn material, 

including pollen, are practically non-toxic (aside to the target pest; Diabrotica) to lepidopteran, 

coleoptera, and other invertebrates. 

Based on these factors, APHIS has concluded that a determination of nonregulated status of DP23211

corn, and subsequent commercial production of this corn variety, will have no effect on listed species or 

species proposed for listing, and would not affect designated habitat or habitat proposed for designation. 

Because of this no-effect determination, consultation under Section 7(a)(2) of the Act or the concurrences 

of the USFWS or NMFS are not required. 
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APPENDIX 2: SUMMARY OF PUBLIC COMMENTS RECEIVED ON THE 

DRAFT ENVIRONMENTAL ASSESSMENT

Summary of Comments Received of the Draft EA

On April 11th, 2023 APHIS published a notice in the Federal Register that it was making the draft 

Environmental Assessment (EA) available for public review and comment for a period of 30 days, ending 

midnight, May 11th, 2023. At the end of the comment period APHIS had received 3 comments on the 

draft EA. 

APHIS NEPA implementing procedures (7 CFR 372) require all comments submitted that are relevant to 

the environmental analysis be evaluated, and responses to comments prepared as needed. APHIS 

evaluated all comments received and has addressed the concerns expressed in the public comments in 

development of the draft and final EA. A summary of the comments received on the draft EA, and APHIS 

response, is provided below. APHIS considered all 3 comments received in preparation of the final EA. A 

full record of all comments received on the draft EA is available online at www.regulations.gov [Docket 

No. APHIS-2020-0098].

Comment ID APHIS-2020-0098-0010

Comment 0010 expressed general opposition to approval of the petition, suggesting that biotechnologyderived crops should go through 30 years of testing before any approval. As discussed in the EA, 

biotechnology-derived crops go through review under the Coordinated Framework. See Section 1.3 –

Coordinated Framework for the Regulation of Biotechnology.

Comment ID APHIS-2020-0098-0011

Comment 0011 expressed concern that the DvSSJ1 dsRNA insect resistant trait in DP23211 corn is 

associated with an animal, and presents cultural/dietary concerns for vegetarians and vegans, plant-based 

diet adherents, who may inadvertently/unknowingly consume DP23211 corn, and thereby DvSSJ1

dsRNA. The DvSSJ1 dsRNA introduced into DP23211 corn was synthesized using the laboratory

techniques Polymerase Chain Reaction (PCR), and in vitro transcription.

17 The 210 base pair sequence in 

DvSSJ1 dsRNA18 was developed to match/target the DvSSJ1 gene in Western corn rootworm (WCR; 

Diabrotica virgifera virgifera), which encodes a cell membrane protein associated with the smooth 

septate junction (SSJ) in WCR gut epithelium; the SSJ is required for proper gut function in WCR.

In brief, the DvSSJ1 dsRNA in DP23211 corn is a sequence of 210 base pairs, base pairs that comprise 

the genome of all plants and animals. The RNA bases are adenine (A), cytosine (C), guanine (G) and 

uracil (U). The DvSSJ1 dsRNA sequence is however specific to WCR. The assertion in comment 0011 

that the dsRNA in DP23211 corn is animal derived is based on the base pair sequence that targets the 

17 See: Hu X, Steimel JP, Kapka-Kitzman DM, and Davis-Vogel C. 2019. Molecular characterization of the insecticidal 

activity of double-stranded RNA targeting the smooth septate junction of western corn rootworm (Diabrotica 

virgifera virgifera) Vol. 14(1), pp. e0210491. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/30629687 18 A base pair (bp) is a fundamental unit of double-stranded (ds) nucleic acids consisting of two nucleobases bound 

to each other by hydrogen bonds. See: NIH. 2023. Base Pair. National Institutes of Health (NIH). Retrieved from 

https://www.genome.gov/genetics-glossary/Base-Pair
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DvSSJ1 gene in WCR, this gene being associated with an insect genome, and insects being part of the 

phylogenetic kingdom Animalia.19

Insects, alive or dead (genetic material), can inherently be part of all harvested corn plants; 

biotechnology-derived, conventional corn, and organic. Insects are a problem for all stored corn grain, 

biotechnology-derived, conventional corn, and organic corn (e.g., weevils, Indian meal moths, grain 

borers, and grain beetles feed on stored corn grain).20 Insects such as flour bugs—also called pantry 

weevils, rice bugs, wheat bugs, or flour worms—are miniscule beetles that may feed on stored dry food in 

a kitchen pantry, or other areas where people store grains. Corn or wheat flour, rice, cake mixes, and pasta 

all may be fed upon by flour bugs. The eggs of flour bugs are so small they cannot be visually detected.21

Individuals preferentially consuming a plant based diet may inadvertently consume insect DNA/RNA in 

greater quantity than that found in DP23211 corn. For example, the DvSSJ1 dsRNA sequence in 

DP23211 corn is a minute fraction, 210 base pairs for the DvSSJ1 dsRNA, out of the 2.5 billion base

pairs that comprise the DP3211 corn genome; thus, DvSSJ1 dsRNA comprises around 8.4 x 10-6 % of the 

DP23211 corn genome. The percentage of DvSSJ1 dsRNA base pairs in DP23211 corn is orders of 

magnitude less than the amount of insect DNA that may be found in commercial corn products due to the 

quantity of insect material permitted in corn products. For example, for corn meal, 1 insect per 50 g corn 

meal, or 25 insect parts per 25 g corn meal are permitted (See the FDA Food Defect Levels Handbook).22 

The genome size of the genus Diabrotica, for one insect, is around 1.56 billion base pairs.23 

It is unlikely that DP23211 corn, a dent corn variety (e.g., Zea mays var. indentata), would be directly 

consumed by humans. Direct consumption of corn is generally limited to sweet corn (Zea mays convar. 

saccharata var. rugosa), popcorn (Zea mays var. everta), and flint corn (Zea mays var. indurata) (e.g., 

polenta). Dent corn is produced primarily for animal feed and industrial uses such as fuel ethanol 

production, although some specialty dent corn varieties may be used for grits, and processed into food 

products such as tortilla chips, corn syrup, corn oil, etc. Only certain hybrid dent corn varieties with 

specific starch properties are used for food purposes. 

19 There are seven main taxonomic ranks: kingdom, phylum or division, class, order, family, genus, and species.

20 BFG. 2023. How to Prevent Corn Bugs in Storage. Bug Free Grains. Retrieved from 

https://www.bugfreegrains.com/blog/grain-insects/prevent-cornbugs#:~:text=Weevils%3A%20Weevils%2C%20such%20as%20maize,leaving%20a%20hollowed%2Dout%20kernel. 21 BFG. 2023. How to Prevent Corn Bugs in Storage. Bug Free Grains. Retrieved from 

https://www.bugfreegrains.com/blog/grain-insects/prevent-cornbugs#:~:text=Weevils%3A%20Weevils%2C%20such%20as%20maize,leaving%20a%20hollowed%2Dout%20kernel. 22 Title 21, Code of Federal Regulations, Part 110.110 allows the Food and Drug Administration (FDA) to establish 

maximum levels of natural or unavoidable defects in foods for human use that present no health hazard. These 

"Food Defect Action Levels" listed in this booklet are set on this premise--that they pose no inherent hazard to 

health. See: US-FDA. 2018. Food Defect Levels Handbook. U.S. Food and Drug Administration. Retrieved from 

https://www.fda.gov/food/ingredients-additives-gras-packaging-guidance-documents-regulatoryinformation/food-defect-levels-handbook 23 Lata D, Coates BS, Walden KKO, Robertson HM, et al. 2022. Genome size evolution in the beetle genus 

Diabrotica. G3 Genes|Genomes|Genetics, Vol. 12(4). Retrieved from https://doi.org/10.1093/g3journal/jkac052 

Last accessed 6/19/2023.
A2-3

Based on the factors discussed, the potential risk of exposure of vegetarians/vegans to insect DNA/RNA

via inadvertent consumption of DP23211 corn products is not expected to appreciably increase in the 

event of deregulation and subsequent production of DP23211 corn. As reviewed in the EA, DvSSJ1 

dsRNA poses no health risk to humans. The DvSSJ1 dsRNA is exempt from the requirement of a 

tolerance under 40 CFR 174.507.

Comment ID APHIS-2020-0098-0012

A comment provided by the Tennessee Farm Bureau Federation (TFBF) stated support for Pioneer 

DP23211 corn, and deregulation of this variety. The TFBF stated that corn brought in $864.8 million in 

cash receipts in 2021, or 19.6% of total farm cash receipts in Tennessee, making it the top revenuegenerating commodity.
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APPENIDX 3: LIST OF PREPARERS

USDA-APHIS

Name, Title, Project Function Education and Experience

Elizabeth Nelson

Chief, Environmental Risk 

Analysis Services

Reviewer 

 Ph.D., Public Health, Capella University

 MBA, University of Maryland University College

 M.S., Health Care Administration, University of Maryland 

University College

 B.S., Biology, Bowie State University

 22 years of professional experience in environmental 

compliance, policy, and management, including preparation 

of NEPA documentation

Lianne Hibbert

Assistant Chief, Biotechnology 

Environmental Analysis Services

Reviewer

 Ph.D., Human Dimension in Natural Resources, University of 

Missouri

 M.S., Fisheries and Wildlife Sciences, University of MissouriColumbia

 B.S., Wildlife Biology, Grambling State University

 18 years of federal service and experience including policy 

development and review, developing program responses to 

congressional requests, and program management.

Ron Hardman

Environmental Protection 

Specialist 

EA Team Lead

 Ph.D., Environment, Integrated Toxicology and Environmental 

Health, Duke University

 M.S., Marine Science/Oceans and Human Health, University 

of North Carolina at Wilmington

 B.S., Biology, Adelphi University

 22 years of experience in environmental/human health risk 

assessment and regulatory compliance

Marlene Cole

Environmental Protection 

Specialist 

Threatened and Endangered 

Species Analysis

 Ph.D., Ecology & Evolution, Rutgers University

 M.F.S, Forest Science (Wildlife Ecology), Yale University, 

School of Forestry and Environmental Studies

 B.A., Biology, Vassar College

 17 years of professional experience in ecological assessment

 10 years of professional experience in environmental 

regulatory compliance

 2 years of experience in environmental impacts of 

biotechnology-derived crops
A4-1 

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