Genective Petition for Determination

Of Non-regulated Status of VCO-01981-5

OECD Unique Identifier: 

VCO-01981-5 

Environmental Assessment 

April 2013

Agency Contact 

Cindy Eck

Biotechnology Regulatory Services

4700 River Road

USDA, APHIS 

Riverdale, MD 20737 

Fax: (301) 734-8669

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and/or Federal agencies before they can be recommended. 
TABLE OF CONTENTS

ACRONYMS AND ABBREVIATIONS .........................................................................................................................II

1 PURPOSE AND NEED.....................................................................................................................................4

1.1 BACKGROUND .....................................................................................................................................................4

1.2 PURPOSE OF THE PRODUCT ....................................................................................................................................4

1.3 COORDINATED FRAMEWORK REVIEW AND REGULATORY REVIEW ..................................................................................5

1.3.1 USDA-APHIS ...........................................................................................................................................5

1.3.2 Environmental Protection Agency..........................................................................................................6

1.3.3 Food and Drug Administration...............................................................................................................6

1.4 PURPOSE AND NEED FOR THIS APHIS ACTION ...........................................................................................................7

1.5 PUBLIC INVOLVEMENT...........................................................................................................................................8

1.5.1 First Opportunity for Public Involvement...............................................................................................8

1.5.2 Second Opportunity for Public Involvement...........................................................................................8

1.6 ISSUES CONSIDERED............................................................................................................................................10

2 AFFECTED ENVIRONMENT .......................................................................................................................... 11

2.1 AGRICULTURAL PRODUCTION OF CORN...................................................................................................................11

2.1.1 Acreage and Areas of Corn Production................................................................................................11

2.1.2 Agronomic Practices: Tillage, Crop Rotation, and Agronomic Inputs .................................................13

2.1.3 Organic Corn Production......................................................................................................................27

2.2 PHYSICAL ENVIRONMENT.....................................................................................................................................28

2.2.1 Water Resources..................................................................................................................................28

2.2.2 Soil Quality...........................................................................................................................................30

2.2.3 Air Quality ............................................................................................................................................32

2.2.4 Climate Change....................................................................................................................................33

2.3 BIOLOGICAL RESOURCES ......................................................................................................................................36

2.3.1 Animal Communities............................................................................................................................36

2.3.2 Plant Communities...............................................................................................................................38

2.3.3 Microorganisms...................................................................................................................................46

2.3.4 Biodiversity...........................................................................................................................................48

2.4 PUBLIC HEALTH..................................................................................................................................................49

2.4.1 Consumer Health .................................................................................................................................49

2.4.2 Worker Safety ......................................................................................................................................52

2.5 ANIMAL FEED....................................................................................................................................................53

2.6 SOCIOECONOMIC ...............................................................................................................................................54
2.6.1 Domestic Economic Environment ........................................................................................................54

2.6.2 Trade Economic Environment..............................................................................................................57

3 ALTERNATIVES............................................................................................................................................ 58

3.1 NO ACTION ALTERNATIVE: CONTINUATION AS A REGULATED ARTICLE..........................................................................58

3.2 PREFERRED ALTERNATIVE: DETERMINATION THAT VCO-01981-5 CORN IS NO LONGER A REGULATED ARTICLE..................58

3.3 ALTERNATIVES CONSIDERED BUT REJECTED FROM FURTHER CONSIDERATION ................................................................59

3.3.1 Prohibit Any VCO-01981-5 Corn from Being Released.........................................................................59

3.3.2 Approve the Petition in Part.................................................................................................................60

3.3.3 Isolation Distance between VCO-01981-5 and Non-GE Corn Production and Geographical Restrictions

60

3.3.4 Requirement of Testing for Presence of VCO-01981-5.........................................................................61

3.4 COMPARISON OF ALTERNATIVES............................................................................................................................61

4 ENVIRONMENTAL CONSEQUENCES ............................................................................................................ 64

4.1 SCOPE OF ANALYSIS ............................................................................................................................................64

4.2 AGRICULTURAL PRODUCTION OF CORN...................................................................................................................64

4.2.1 Acreage and Area of Corn Production..................................................................................................65

4.2.2 Agronomic Practices............................................................................................................................66

4.2.3 Organic Corn Production......................................................................................................................69

4.3 PHYSICAL ENVIRONMENT.....................................................................................................................................70

4.3.1 Water Resources..................................................................................................................................70

4.3.2 Soil Quality...........................................................................................................................................72

4.3.3 Air Quality ............................................................................................................................................74

4.3.4 Climate Change....................................................................................................................................75

4.4 BIOLOGICAL RESOURCES ......................................................................................................................................77

4.4.1 Animal Communities............................................................................................................................77

4.4.2 Plant Communities...............................................................................................................................80

4.4.3 Microorganisms...................................................................................................................................84

4.4.4 Biodiversity...........................................................................................................................................86

4.5 PUBLIC HEALTH..................................................................................................................................................90

4.5.1 Consumer Health .................................................................................................................................90

4.5.2 Worker Safety ......................................................................................................................................92

4.6 ANIMAL FEED....................................................................................................................................................93

4.7 SOCIOECONOMIC IMPACTS...................................................................................................................................95

4.7.1 Domestic Economic Environment......................................................................................................95

4.7.2 Trade Economic Environment............................................................................................................98

ii
5 CUMULATIVE IMPACTS............................................................................................................................. 101

5.1 ASSUMPTIONS USED FOR CUMULATIVE IMPACTS ANALYSIS ......................................................................................101

5.2 CUMULATIVE IMPACTS: ACREAGE AND AREA OF CORN PRODUCTION .........................................................................102

5.3 CUMULATIVE IMPACTS: AGRONOMIC PRACTICES ....................................................................................................103

5.4 CUMULATIVE IMPACTS: ORGANIC CORN PRODUCTION ............................................................................................104

5.5 CUMULATIVE IMPACTS: PHYSICAL ENVIRONMENT...................................................................................................105

5.6 CUMULATIVE IMPACTS: BIOLOGICAL RESOURCES....................................................................................................105

5.7 CUMULATIVE IMPACTS: PUBLIC HEALTH AND ANIMAL FEED......................................................................................107

5.8 CUMULATIVE IMPACTS: DOMESTIC ECONOMIC ENVIRONMENT .................................................................................107

5.9 CUMULATIVE IMPACTS: TRADE ECONOMIC ENVIRONMENT.......................................................................................108

6 THREATENED AND ENDANGERED SPECIES................................................................................................ 110

6.1 POTENTIAL EFFECTS OF VCO-01981-5 CORN ON TES ............................................................................................112

6.2 POTENTIAL EFFECTS OF THE USE OF GLYPHOSATE ...................................................................................................113

6.2.1 EPA Endangered Species Protection Program (ESPP) ........................................................................114

6.2.2 EPA TES Evaluation Process ...............................................................................................................114

6.2.3 Ecological Risks of Glyphosate ...........................................................................................................115

6.2.4 Potential Impacts of Glyphosate Use in the Production of Corn........................................................118

7 CONSIDERATION OF EXECUTIVE ORDERS, STANDARDS, AND TREATIES RELATING TO ENVIRONMENTAL 

IMPACTS............................................................................................................................................................ 120

7.1 EXECUTIVE ORDERS WITH DOMESTIC IMPLICATIONS................................................................................................120

7.2 INTERNATIONAL IMPLICATIONS............................................................................................................................122

7.3 COMPLIANCE WITH CLEAN WATER ACT AND CLEAN AIR ACT ....................................................................................124

7.4 IMPACTS ON UNIQUE CHARACTERISTICS OF GEOGRAPHIC AREAS ...............................................................................124

7.5 NATIONAL HISTORIC PRESERVATION ACT (NHPA) OF 1966 AS AMENDED..................................................................126

8 LIST OF PREPARERS................................................................................................................................... 127

9 REFERENCES ............................................................................................................................................. 128

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LIST OF TABLES

TABLE 2-1: CORN: TOTAL FERTILIZER PRIMARY NUTRIENT APPLICATIONS, 2010. ..........................................................................16

TABLE 2-2: CORN: TOTAL INSECTICIDE APPLICATIONS, 2010. ..................................................................................................16

TABLE 2-3: CORN: TOTAL HERBICIDE APPLICATIONS, 20101. ...................................................................................................18

TABLE 2-4: PERCENTAGE OF HERBICIDE-RESISTANT, INSECT-RESISTANT, STACKED TRAIT, TOTAL GE CORN, AND TOTAL CORN

ACREAGE PLANTED IN SELECT STATES IN 2012. ............................................................................................................21

TABLE 2-5 PERCENT OF U.S. CORN ACRES1 TREATED WITH HERBICIDES IN 1995, 2000, 2005 AND 2010.......................................22

TABLE 2-6: U.S. CHLOROACETAMIDE-RESISTANT WEEDS THROUGH DECEMBER 2012..................................................................24

TABLE 2-7: U.S. 4-HPPD INHIBITOR-RESISTANT WEEDS THROUGH DECEMBER 2012..................................................................24

TABLE 2-8: PHOTOSYSTEM II INHIBITOR-RESISTANT WEEDS THROUGH DECEMBER 2012 ..............................................................24

TABLE 2-9: U.S. GLYPHOSATE-RESISTANT WEEDS THROUGH DECEMBER 2012 ...........................................................................26

TABLE 2-10: U.S. GLYPHOSATE-RESISTANT WEEDS AS OF DECEMBER 2012. ..............................................................................40

TABLE 2-11: U.S. STATES WITH MORE THAN ONE WEED SPECIES WITH GLYPHOSATE RESISTANCE.....................................................42

TABLE 3-1: SUMMARY OF ISSUES OF POTENTIAL IMPACTS AND CONSEQUENCES OF ALTERNATIVES. ...................................................61

TABLE 4-1: CHANGES IN MAJOR HERBICIDE USE BETWEEN 2005 AND 2010...............................................................................67
LIST OF FIGURES

FIGURE 1: THE 2011 ESTIMATED AMOUNT OF PLANTED CORN ACREAGE BY U.S. COUNTY IN SELECTED STATES ................................12

FIGURE 2: US AND WORLD CORN EXPORTS FOR MARKETING YEARS 2000/2001 TO 2010/2011....................................................99

FIGURE 3: US AND MAJOR EXPORTERS OF CORN FOR MARKETING YEARS 1960/1961-2011/2012...............................................100
ACRONYMS AND ABBREVIATIONS

AIA advanced informed agreement

AOSCA American Organization of Seed Certifying Agencies

APHIS Animal and Plant Health Inspection Service

BRAD Biopesticide Registration Action Document

BRS Biotechnology Regulatory Services (within USDA–APHIS)

Bt Bacillus thuringiensis protein

CAA Clean Air Act

CBD Convention on Biological Diversity

CEQ Council on Environmental Quality

CFR Code of Federal Regulations (United States)

CH4 methane

CO carbon monoxide

CO2 carbon dioxide

DNA deoxyribonucleic acid

DT drought tolerant

EA environmental assessment

EIS environmental impact statement

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

FFP food, feed, or processing

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act

FR Federal Register

GDP gross domestic product

GE genetically engineered

GHG greenhouse gas

GMO genetically modified organism

IP Identity Preservation

IPCC Intergovernmental Panel on Climate Change
ACRONYMS AND ABBREVIATIONS

IRM Insect Resistance Management

ISPM International Standard for Phytosanitary Measure

IPPC International Plant Protection Convention

LD50 lethal dose that kills 50% of the animals being tested

NO2 nitrogen dioxide

N2O nitrous oxide

NAAQS National Ambient Air Quality Standards

NABI North American Biotechnology Initiative

NAPPO North American Plant Protection Organization

NEPA National Environmental Policy Act of 1969 and subsequent amendments

NHPA National Historic Preservation Act

NOEL no observable effect level

NRC National Research Council

PPRA Plant Pest Risk Assessment

PPA Plant Protection Act

PRA pest risk analysis

RNA ribonucleic acid

TES threatened and endangered species

TSCA Toxic Substances Control Act

U.S. United States

USDA U.S. Department of Agriculture

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

USDA-FAS U.S. Department of Agriculture-Foreign Agricultural Service

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

USDA-NOP U.S. Department of Agriculture-National Organic Program

USC United States Code

WPS Worker Protection Standard for Agricultural Pesticides

iii
1 PURPOSE AND NEED

1.1 Background

Genective SA of Chappes, France with the Bayer Company of Research Triangle Park, North 

Carolina submitted a petition, APHIS Number 11-342-01, to The United States Department of 

Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) in December 2011.

The purpose of the petition is to support a determination of nonregulated status for VCO-01981-5 

corn (henceforth referred to as VCO-01981-5 corn), which is resistant1 to the herbicide, 

glyphosate. The event VCO-01981-5 corn is currently regulated under 7 CFR part 340. 

Interstate movements and field trials of event VCO-01981-5 have been conducted under permits 

issued or notifications acknowledged by APHIS since 2007. These field trials were conducted 

within two corn-growing areas in the U.S since 2007 in Puerto Rico and since 2008 in Iowa. 

Data resulting from these field trials are described in the petition (Genective, 2012) and analyzed 

for plant pest risk in the USDA-APHIS Plant Pest Risk Assessment (PPRA) (USDA-APHIS, 

2012a)

The petition stated that APHIS should not regulate VCO-01981-5 corn because it does not 

present a plant pest risk. If a determination of nonregulated status is made, it would include 

VCO-01981-5 corn, any progeny derived from crosses between VCO-01981-5 corn and 

conventional corn, and crosses of VCO-01981-5 corn with other biotechnology-derived corn 

lines that are no longer subject to the regulatory requirements of 7 CFR part 340 promulgated 

under the authority of the Plant Protection Act of 2000 (PPA).

1.2 Purpose of the Product

A modified epsps gene, from the bacterium Arthrobacter globiformis was transformed into corn 

for resistance to glyphosate. The protein expressed by the gene, 5-enolpyruvylshikimate-3-

phosphate synthase (EPSPS) protein, EPSPS ACE5, confers resistance to the common herbicide 

glyphosate and has greater enzymatic half-life than the native protein, but somewhat less than the 

native enzyme from corn. Genective has developed VCO-01981-5 to make available an 

additional variety of glyphosate resistant corn to growers and corn seed suppliers for weed 

1

“Resistance” to herbicides is defined by the HRAC (Herbicide Resistance Action Committee) 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 HRAC, Guideline to the Management of Herbicide Resistance, 2013, Herbicide Resistance 

Action Committee, Available: http://www.hracglobal.com/Publications/ManagementofHerbicideResistance.aspx, 

January 22 2013. Several technologies are available that can be used to develop herbicide resistance in plants 

including classical breeding, tissue culture, mutagenesis and genetic engineering. “Tolerance” is distinguished from 

resistance and defined by HRAC (2013) as the inherent ability of a plant to survive and reproduce following 

exposure to a herbicide treatment. This implies the circumstance in which there is no selection or genetic 

manipulation to make the plant tolerant; it is naturally tolerant. Throughout this EA (Environmental Assessment), 

APHIS has used the terms “resistance” and “tolerance” consistent with the definitions of the HRAC. It should be 

noted however, that different terms for the same concept may be used interchangeably in some instances. In its 

petition to USDA APHIS Genective .referenced the subject as, “glyphosate-tolerant maize,” and used the term 

“herbicide tolerant” throughout its documentation to describe it (Genective, 2011). This terminology can be 

considered synonymous with “herbicide-resistant” (HR) used in this EA.

4

 
management. EPA regulated applications of glyphosate will be the same as for other current 

varieties of corn being produced that have similar resistance to the herbicide.

1.3 Coordinated Framework Review and Regulatory Review

Since 1986, the United States government has regulated GE organisms pursuant to Federal 

regulations published in the Federal Register entitled The Coordinated Framework for the 

Regulation of Biotechnology (51 FR 23302, 1986)(henceforth referred to here as the Coordinated 

Framework), and the policy statement for foods derived from new plant varieties (57 FR 22984, 

1992). The Coordinated Framework, published by the Office of Science and Technology Policy, 

describes the comprehensive federal regulatory policy for ensuring the safety of biotechnology 

research and products and explains how federal agencies will use existing Federal statutes in a 

manner to ensure public health and environmental safety while maintaining regulatory flexibility 

to avoid impeding the growth of the biotechnology industry. The Coordinated Framework is 

based on several important guiding principles: (1) agencies should define those transgenic 

organisms subject to review to the extent permitted by their respective statutory authorities; (2) 

agencies are required to focus on the characteristics and risks of the biotechnology product, not 

the process by which it is created; (3) agencies are mandated to exercise oversight of GE 

organisms only when there is evidence of “unreasonable” risk.

The Coordinated Framework explains the regulatory roles and authorities for the three major 

agencies involved in regulating GE organisms: USDA APHIS, the Environmental Protection 

Agency (EPA), and the Food and Drug Administration (FDA). A summary of each role follows.

1.3.1 USDA-APHIS

APHIS regulations at 7 Code of Federal Regulations (CFR) part 340, which were promulgated 

pursuant to authority granted by the Plant Protection Act, as amended (7 United States Code 

(U.S.C.) 7701–7772), regulate the introduction (importation, interstate movement, or release into 

the environment) of certain GE organisms and products. A GE organism is no longer subject to 

the plant pest provisions of the Plant Protection Act or to the regulatory requirements of 7 CFR 

part 340 when APHIS determines that it is unlikely to pose a plant pest risk. A GE organism is 

considered a regulated article if the donor organism, recipient organism, vector, or vector agent 

used in engineering the organism belongs to one of the taxa listed in the regulation (7 CFR 

340.2) and is also considered a plant pest. A GE organism is also regulated under part 340 when 

APHIS has reason to believe that the GE organism may be a plant pest or APHIS does not have 

information to determine if the GE organism is unlikely to pose a plant pest risk.

A person may petition the agency that a particular regulated article is unlikely to pose a plant 

pest risk, and, therefore, is no longer regulated under the plant pest provisions of the PPA or the 

regulations at 7 CFR 340. Under § 340.6(c)(4) the petitioner must provide information related to 

plant pest risk that the agency may use to determine whether the regulated article is unlikely to 

present a greater plant pest risk than the unmodified organism. A GE organism is no longer 

subject to the regulatory requirements of 7 CFR part 340 or the plant pest provisions of the Plant 

Protection Act when APHIS determines that it is unlikely to pose a plant pest risk.

5
1.3.2 Environmental Protection Agency

EPA is responsible for regulating the sale, distribution, and use of pesticides, including pesticides 

that are produced by an organism through techniques of modern biotechnology. The EPA 

regulates plant-incorporated protectants (PIPs) under the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA) (7 U.S.C. 136 et seq.) and certain biological control organisms under 

the Toxic Substances Control Act (TSCA) (15 U.S.C. 53 et seq.). Before planting a crop 

containing a PIP, a company must seek an experimental use permit from EPA. Commercial 

production of crops containing PIPs for purposes of seed increases and sale requires a FIFRA 

Section 3 registration with EPA. 

Under FIFRA (7 U.S.C. 136 et seq.), EPA regulates the use of pesticides, and requires 

registration of all pesticide products for all specific uses prior to distribution for sale. EPA 

examines: the ingredients of the pesticide; the particular site or crop on which it is to be used; the 

amount, frequency, and timing of its use; storage and disposal practices. Prior to registration for 

a new use for a new or previously registered pesticide, EPA must determine through testing that 

the pesticide does not cause unreasonable adverse effects on humans, the environment, and nontarget species when used in accordance with label instructions. EPA must also approve the 

language used on the pesticide label in accordance with 40 CFR part 158. Once registered, a 

pesticide may only be legally used in accordance with directions and restrictions on its label. 

The overall intent of the label is to provide clear directions for effective product performance, 

while minimizing risks to human health and the environment. The Food Quality Protection Act 

(FQPA) of 1996 amended FIFRA, enabling EPA to implement periodic registration review of 

pesticides to ensure they are meeting current scientific and regulatory standards of safety and 

continue to have no unreasonable adverse effects (US-EPA, 2011c). 

EPA also sets tolerances (maximum residue levels) or establishes an exemption from the 

requirement for a tolerance, under the Federal Food, Drug, and Cosmetic Act (FFDCA). A 

tolerance is the amount of pesticide residue that can remain on or in food for human consumption 

or animal feed. Before establishing a pesticide tolerance, EPA is required to reach a safety 

determination based on a finding of reasonable certainty of no harm under the FFDCA, as 

amended by the FQPA. FDA enforces the pesticide tolerances set by EPA.

1.3.3 Food and Drug Administration

FDA regulates GE organisms under the authority of the FFDCA (21 U.S.C. 301 et seq.). The 

FDA published its policy statement concerning regulation of products derived from new plant 

varieties, including those derived from genetic engineering, on May 29, 1992 (57 FR 22984). 

Under this policy, FDA implements a voluntary consultation process to ensure that human food 

and animal feed safety issues or other regulatory issues, such as labeling, are resolved before 

commercial distribution of bioengineered food. This voluntary consultation process provides a 

way for developers to receive assistance from FDA in complying with their obligations under 

Federal food safety laws prior to marketing.

More recently (June 2006), FDA published recommendations in “Guidance for Industry: 

Recommendations for the Early Food Safety Evaluation of New Non-Pesticidal Proteins 

Produced by New Plant Varieties Intended for Food Use” (US-FDA, 2006). This establishes 

voluntary food safety evaluations for new non-pesticidal proteins produced by new plant 

6
varieties intended to be used as food, including bioengineered plants. Early food safety 

evaluations help make sure that potential food safety issues related to a new protein in a new 

plant variety are addressed early in development. These evaluations are not intended as a 

replacement for a biotechnology consultation with FDA, but the information may be used later in 

the biotechnology consultation.

VCO-01981-5 corn is within the scope of the FDA policy statement concerning regulation of 

products derived from new plant varieties, including those produced through GE. In 2009, 

Athenix Corp., now an affiliate of Bayer CropScience LP, submitted an Early Food Safety 

Evaluation to FDA. Genective had the license for use of VCO-01981-5 from Athenix, and Bayer 

is now assuming the interest of Athenix in this product. The FDA review for the Early 

Evaluation (NPC 000012: Agency Response Letter) was completed with no further questions in 

October, 2010 (FDA, 2010). Genective SA initiated the consultation process with FDA for the 

commercial distribution of event VCO-01981-5 and submitted a safety and nutritional 

assessment of food and feed derived from VCO-01981-5 to the FDA on March 5, 2012 (will be 

assigned FDA no. BNF-000137). FDA is presently evaluating the submission. On the final food 

safety consultation regarding VCO-01981-5 corn, submitted by Genective SA to FDA, no recent 

questions have been raised (personal communication, I. Coats, Bayer, February 27, 2013).

1.4 Purpose and Need for this APHIS Action

As noted in the previous section, any party can petition APHIS to seek a determination of 

nonregulated status for a GE organism that is regulated currently under 7 CFR 340. As required 

by 7 CFR 340.6, APHIS must respond to petitioners that request a determination of the regulated 

status of GE organisms, including GE plants such as Genective VCO-01891-5 corn. When a 

petition for nonregulated status is submitted, APHIS must determine if the GE organism is 

unlikely to pose a plant pest risk. The petitioner is required to provide information under § 

340.6(c)(4) related to plant pest risk that the agency may use to determine whether the regulated 

article is unlikely to present a greater plant pest risk than the unmodified organism. A GE 

organism is no longer subject to the regulatory requirements of 7 CFR part 340 or the plant pest 

provisions of the PPA when APHIS determines that it is unlikely to pose a plant pest risk.

APHIS must respond to the petition from Genective requesting a determination of nonregulated 

status for VCO-01981-5 corn. APHIS has prepared this EA to consider the potential 

environmental effects of an agency determination of nonregulated status of VCO-01981-5 corn. 

This action is consistent with regulations for the National Environmental Policy Act (NEPA) 

established by the Council of Environmental Quality (CEQ), and those of the USDA APHIS 

NEPA-implementing regulations and procedures (40 CFR parts 1500-1508, 7 CFR part 1b, and 7 

CFR part 372). This EA has been prepared in order to specifically evaluate the effects on the 

quality of the human environment2 that may result from a determination of nonregulated status

for VCO-01981-5 corn.

2

Under NEPA regulations, the “human environment” includes “the natural and physical environment and the 

relationship of people with that environment” (40 CFR §1508.14).

7

 
1.5 Public Involvement

APHIS routinely seeks public comment on EAs prepared in response to petitions seeking a 

determination of nonregulated status of a regulated GE organism. APHIS does this through a 

notice published in the Federal Register. On March 6, 2012, APHIS published a notice3 in the 

Federal Register advising the public that APHIS is implementing changes to the way it solicits 

public comment when considering petitions for determinations of nonregulated status for GE 

organisms to allow for early public involvement in the process. As identified in this notice, 

APHIS publishes two separate notices in the Federal Register for petitions for which APHIS 

prepares an EA. The first notice announces the availability of the petition, and the second notice 

announces the availability of the APHIS decision-making documents. As part of the new 

process, with each of the two notices published in the Federal Register, there is an opportunity 

for public involvement:

1.5.1 First Opportunity for Public Involvement

Once APHIS deems a petition complete, the petition is made available to the public for 60 days 

to provide an opportunity to comment on issues regarding the petition itself and give input that 

will be considered by the Agency as it develops its EA and PPRA. APHIS publishes a notice in 

the Federal Register to inform the public that APHIS will accept written comments regarding a 

petition for a determination of nonregulated status for a period of 60 days from the date of the 

notice. This availability of the petition for public comment is announced in a Federal Register

notice.

1.5.2 Second Opportunity for Public Involvement

Assuming an EA is sufficient, the PPRA and EA are developed, and a notice of their availability 

is published in a second Federal Register notice. This second notice follows one of two 

approaches for public participation based on whether or not APHIS decides the petition for a 

determination of nonregulated status is for a GE organism that raises substantive new issues:

Approach 1: GE organisms that do not raise substantive new issues.

This approach for public participation is used when APHIS decides, based on the review of the 

petition and our evaluation and analysis of comments received from the public during the 60-day 

comment period on the petition, that it involves a GE organism that does not raise new 

biological, cultural, or ecological issues because of the nature of the modification or the 

Agency’s familiarity with the recipient organism. After developing its EA, finding of no 

significant impact (FONSI), and PPRA, APHIS publishes a notice in the Federal Register 

announcing its preliminary regulatory determination and the availability of the EA, FONSI, and 

PPRA for a 30-day public review period.

If no information is received that would warrant substantially changing the APHIS analysis or 

determination, the Agency’s preliminary regulatory determination becomes effective upon public 

notification through an announcement on its website. No further Federal Register notices are 

published announcing the final regulatory determination.

3

This notice can be accessed at: http://www.gpo.gov/fdsys/pkg/FR-2012-03-06/pdf/2012-5364.pdf

8

 
Approach 2. For GE organisms that raise substantive new issues not previously reviewed by 

APHIS. A second approach for public participation is used when APHIS determines that the 

petition for a determination of nonregulated status is for a GE organism that involves substantive 

new issues. This could include petitions for a recipient organism that has not previously been 

determined by APHIS to have nonregulated status or when APHIS determines that gene 

modifications involves substantive biological, cultural, or ecological issues not previously 

analyzed by APHIS. Substantive issues are identified based on the Agency’s review of the 

petition and its evaluation and analysis of comments received from the public during the 60-day 

comment period for the petition. 

APHIS solicits comments on its draft EA and draft PPRA for 30 days, as announced in a Federal 

Register notice. APHIS reviews and evaluates comments and other relevant information, then

revises the PPRA as necessary and prepares a final EA. Following preparation of these 

documents, APHIS approves or denies the petition, then announces its decision in the Federal 

Register, and provides notice of the availability of the final EA, PPRA, NEPA decision 

document, and regulatory determination.

More details about this expansion of opportunities for stakeholder review and comment are 

available in the Federal Register notice4 published on March 6, 2012.

APHIS has determined that this EA will follow Approach 1. The issues considered in this EA 

were developed by reviewing the public concerns, including public comments received in 

response to the Federal Register notice (77 F.R. 41357-8) announcing the availability of the 

petition (i.e., the first opportunity for public involvement previously described in this document), 

as well as issues noted in public comments submitted for other EAs of GE organisms, and 

concerns described in lawsuits and expressed by various stakeholders. These issues, including 

those regarding the agricultural production of corn using various production methods and the 

environmental and food/feed safety of GE plants, were addressed to analyze the potential 

environmental impacts of Genective VCO-01891-5 corn.

The public comment period for VCO-01981-5 corn petition closed on September 11, 2012. At 

its closing, the docket file contained a total of 78 submissions to the docket. Some of the 

submissions contained multiple attached comments; there were a total of 4,604 public comments. 

The majority of the comments expressed a general dislike of the use of GE organisms or were 

form letters sent to all of the dockets which were open at the time that this docket was open. The 

form letter expressed a concern that there were too many dockets published on the same day. It 

also referenced other open dockets and potential effects from the use of the subjects of those 

petitions. Another comment addressed concerns that APHIS’ regulations were inadequate to 

fully regulate GE crops. These issues are outside the scope of this EA. The issues raised that 

were related to the VCO-01981-5 corn petition included:

• Development of glyphosate resistant weeds.

• The fate of glyphosate in water.

• The effects of glyphosate use on biological organisms.

4

This notice can be accessed at: http://www.gpo.gov/fdsys/pkg/FR-2012-03-06/pdf/2012-5364.pdf

9

 
• Concern that cross-pollination between GE and organic or crops for GE-sensitive markets 

will affect sales for growers of these crops.

• Concerns that Genective VCO-01981-5 Corn is not approved in all export markets.

1.6 Issues Considered

The list of resource areas considered in this EA were developed by APHIS through experience in 

considering public concerns and issues raised in public comments submitted for other EAs of GE 

organisms. The resource areas considered also address concerns raised in previous and unrelated 

lawsuits, as well as issues that have been raised by various stakeholders in the past. The resource 

areas considered in this EA can be categorized as follows: 

Agricultural Production Considerations:

• Acreage and Areas of Corn Production

• Agronomic Practices

• Organic Corn Production

• Specialty Corn Production

Environmental Considerations:

• Water Resources

• Soil

• Air Quality 

• Climate Change

• Animals

• Plants

• Microorganisms

• Biological Diversity

Human Health Considerations:

• Public Health

• Worker Safety

Livestock Health Considerations:

• Livestock Health/Animal Feed

Socioeconomic Considerations:

• Domestic Economic Environment

• Trade Economic Environment

10
2 AFFECTED ENVIRONMENT

2.1 Agricultural Production of Corn

2.1.1 Acreage and Areas of Corn Production

Corn is the world‘s most widely cultivated cereal, reflecting its ability to adapt to a wide range of 

production environments (OECD, 2003). Corn is an annual plant typically grown in zones of 

abundant rainfall and fertile soils (OECD, 2003). In the U.S., moisture levels and number of 

frost-free days required to reach maturity are ideal for corn to be grown within temperate regions 

(see, e.g., (IPM, 2004; IPM, 2007); although corn is reported to have a strong ability to adapt to 

extreme and variable conditions of humidity, sunlight, altitude, and temperature (OECD, 2003).

In 2009, the U.S. produced 40% of the total world supply of corn (USDA-OCE, 2011b). Corn

is cultivated worldwide, including Argentina, South Africa, Brazil, Canada, China, and the

former Soviet Union States, including the Ukraine (USDA-OCE, 2011b). Egypt, the EU, 

Japan, Mexico, Southeast Asia, and South Korea are net importers of corn (USDA-OCE, 

2011b). Approximately 15 to 20% of the U.S. corn production is exported (USDA-OCE, 

2011b).

Corn is the most widely cultivated feed grain, accounting for more than 95% of total value

and production of feed grains (USDA-ERS, 2011f). Corn is grown in all 48 of the continental

U.S. states with production concentrated in the Corn Belt, loosely defined as the states of

Illinois, Iowa, Indiana, the eastern portions of South Dakota and Nebraska, western Kentucky

and Ohio, and the northern two-thirds of Missouri (USDA-NASS, 2010b; USDA-ERS, 2011b). 

Iowa and Illinois, the two top corn producing states, typically account for slightly more than

one-third of the total U.S. crop (USDA-ERS, 2011f). In the U.S. for the 2012 production

year, corn was cultivated on over 96 million acres, a 5% increase in corn acreage from

2011(USDA-NASS, 2012a). Within the 2010 acreage, corn for silage was cultivated on

approximately 5.6 million acres, or approximately 6% of the total corn production area

(USDA-NASS, 2012b). Corn production in 2010 was estimated at 12.4 billion bushels,

valued at an estimated $5.18 per bushel in 2010 and $6.20 in 2011 (USDA-NASS, 2012a; 

USDA-NASS, 2012c). Corn futures are highly variable, and corn on 19 June 2012 traded on the

Chicago Board of Trade at $5.74 per bushel for a December 2012 contract; while by 18 

July, corn futures traded at $7.86 for the same contract (CME-Group, 2012).

11
Figure 1: The 2011 Estimated Amount of Planted Corn Acreage by U.S. County in Selected 

States

Source: (USDA-NASS, 2011d)

Corn acreage in the U.S. increased during the second half of the 2000s. The establishment of

a bioethanol industry using corn as a feed stock has been identified as one of the key elements

in the increase in acreage devoted to corn, with more than 40% of the corn harvest now 

dedicated to corn-based biofuel production Wilson, 2011 (Wilson, 2011). Since 2006, many

U.S. cotton farmers have converted to corn and soybean because of favorable prices (USDAERS, 2009).

Growers can choose from a large number of corn hybrids produced from traditional breeding

or GE systems (NCGA, 2009). Like the major commodity crops cotton and soybean, GE

varieties of corn have been adopted during the past decade. In 2000, approximately 6%

of all corn planted was GE herbicide-resistant, and 25% of the total crop was GE

(Benbrook, 2009b). By 2009, 22% of the US corn crop was GE herbicide-resistant and 17% 

was insect-resistant (Benbrook, 2009a; USDA-ERS, 2010a). As of 2011, it was estimated that

approximately 23% of the crop was GE herbicide-resistant only, 16% was GE insectresistant only, 49% was a stacked gene variety (likely both herbicide resistant and insect 

resistant), and 88% of the total U.S. corn crop was planted in some GE variety (USDANASS, 2011b).

12
2.1.2 Agronomic Practices: Tillage, Crop Rotation, and Agronomic Inputs

Corn planting dates range from late March in Kansas to late May in North Dakota, (IPM, 

2007). Corn ideally is planted when soil temperature reaches 55°F at 2-inch depth (IPM, 2007).

Growers can choose from several different crop management practices depending upon 

geographic cultivation area and end-use market (IPM, 2004; IPM, 2007). Common corn 

cultivation practices include various methods of tillage, selection of a crop rotation system, and 

other agronomic inputs.

Tillage

Prior to planting, the soil must be stripped of weeds that would otherwise compete with the

crop for space, water, and nutrients. Field preparation is accomplished through a variety of

tillage systems, with each system defined by the remaining plant residue on the field. A

number of different tillage and planting systems are used in corn production, including

primary and/or secondary tillage or no pre-plant tillage operations (IPM, 2007 63). 

Conservation tillage includes reduced till, mulch-till, eco-fallow, strip-till, ridge-till, zerotill, and no-till (IPM, 2007). Conventional tillage is associated with intensive plowing and

leaving less than 15% crop residue in the field; reduced tillage is associated with 15 to 30%

crop residue; and conservation tillage, including no-till practices requiring herbicide

application on the plant residue from the previous season, is associated with at least 30% crop

residue and substantially less soil erosion than other tillage practices (US-EPA, 2009a). 

Increases in total acres dedicated to conservation tillage have been attributed to an increased use

of GE crops including corn, reducing the need for mechanical weed control (USDA-ERS, 2006; 

USDA-NRCS, 2006b; Towery and Werblow, 2010b). For example, the introduction of 

herbicide-resistant varieties of cotton and soybean encouraged some growers to adopt 

conservation practices that had not been previously fully adopted in the field (Givens et al., 

2009). However, availability of herbicide-resistant corn was likely not the only driving factor in 

adoption of these practices, as many corn growers had already adopted conservation tillage 

practices before the herbicide-resistant corn varieties were introduced to the market (Givens et 

al., 2009). 

Conservation tillage, although highly valued as a means to enhance soil quality and preserve soil 

moisture, itself has been identified as a potential challenge for corn disease 

management as well as pest management. The surface residues have been identified as an

inoculum source for certain disease-causing organisms (Robertson et al., 2009). This is

especially a problem for growers whose rotation is corn-to-corn with minimal tillage 

(Robertson et al., 2009). Diseases associated with corn residues include Anthracnose (caused 

by the fungus Colletotrichum graminicola), Eyespot (caused by the fungus Kabatiella zeae),

Goss‘s wilt (caused by the bacteria Corynebacterium nebraskense), Gray leaf spot (caused by

the fungus Cercospora zeae-maydis), and Northern corn leaf blight (caused by the fungus

Helminthosporium turcicum) (Robertson et al., 2009). For each of these diseases, the disease

agent overwinters in the cool and moist soil, and inoculum from the corn residue then infects

the new crop (Robertson et al., 2009). Disease control measures include cultivation of 

resistant hybrids, crop rotation, and more careful balancing of conservation tillage with 

residue management (Robertson et al., 2009).

13
Crop Rotation

Crop rotations (successive planting of different crops on the same land in subsequent years) are

used to optimize soil nutrition and fertility, reduce pathogen loads, control volunteers (carry

over in successive years), and limit the potential for weeds to develop resistance to herbicides

(IPM, 2004; IPM, 2007; USDA-ERS, 2010b). Corn can be grown successfully in conservation

tillage system if rotated with other crops such as wheat and soybeans, which will reduce 

some of the problems encountered with conservation tillage (IPM, 2007).

Rotations need not be fixed, but dynamic, and increased flexibility of rotations may be favored as 

growers respond to soil moisture content, yield increases from crop sequence advantages or 

interference, pest management requirements and market conditions; corn planted by election in 

dynamic sequences may lead to outperformance of wheat yield over that in 5 year fixed rotations 

(Tanaka and Liebig, 2012).

In 2010, 71 percent of corn acreage in 19 surveyed states was under some form of rotation 

(USDA-NASS, 2011c). Cropland used for corn and soybean production is nearly identical in 

many areas, where over 90 percent of the cropped area is planted in a two-year corn-soybean 

rotation (Hoeft et al., 2000b). 

The benefits of corn rotation with, for example soybean, are many and include (Al-Kaisi et al., 

2003):

• Improved yield and profitability of one or both crops;

• Decreased need for additional nitrogen on the crop following soybean; 

• Increased residue cover resulting in reduced soil erosion;

• Mitigation or disruption of disease, insect, and weed cycles;

• Reduced soil erosion;

• Increased soil organic matter;

• Improved soil tilth and soil physical properties; and

• Reduced runoff of nutrients, herbicides, and insecticides.

While soybean-corn rotation is largely practiced in Iowa (USDA-ERS, 2006) and of other 

Midwest states, recent encouragement has been given to rotate with a third crop such as oats or 

alfalfa because the sequence may suppress rotation crop pathogens (L. Leandro, Iowa State 

University: (see Masterson (2010; Leandro and Kull, 2012). A three or four year crop rotation 

could also potentially reduce total use of herbicides without increasing weed production (Davis 

et al., 2012).Central and Northern Great Plains rotations using no-till might include wheat, 

sorghum, dry edible beans, millet, or sunflower (Beck et al., 1998).Southern states include corn 

in rotation with cotton, soybeans and peanuts (Webster and Nichols, 2012).Recently, there has 

been an increase in continuous corn rotations due to high corn commodity prices and the strong 

demand for corn grain (USDA-ERS, 2011b). Consecutive plantings of corn are estimated at

around 10% in 10 corn states (USDA-ERS, 2006) and closer to 30% in Iowa (Duffy, 2011). 

Continuous corn in the Corn Belt frequently requires at-planting or pre-plant pesticide treatments 

to control corn pests and pathogens as well as supplemental fertilizer treatments (IPM, 2004; 

Erickson and Lowenberg-DeBoer, 2005; Sawyer, 2007; Stockton, 2007). Corn-to-corn rotations 

also may require a change in tillage practices. Corn-to-corn cultivation may produce 

substantially greater quantities of field residue, requiring additional tillage prior to planting 

(Erickson and Lowenberg-DeBoer, 2005). Continuous corn rotations require more fertilizer 

14
treatments to replace diminished soil nitrogen levels and more pesticide applications (Bernick, 

2007; Laws, 2007; Erickson and Alexander, 2008). The increased adoption of corn-to-corn 

rotation, mainly in conventional and GE production systems, has been attributed to rising corn 

demand and prices (Hart, 2006; Stockton, 2007).

Corn has been reported as a volunteer in crops the year after harvest (Beckett and Stoller, 

1988; USDA-APHIS, 2012a). This issue is discussed in Subsection 2.3.2 Plants: Corn as

a Volunteer and the corresponding impacts analysis in Subsection 4.4.2 Plants: Corn as 

a Volunteer.

Agronomic Inputs

Corn production typically involves the extensive use of agronomic inputs to maximize grain 

yield (Ritchie et al., 2008). Agronomic inputs include fertilizers to supplement available

nutrients in the soil; pesticides to reduce pest plant, insect, and/or microbial populations; and 

water to ensure normal plant growth and development (Howell et al., 1998; IPM, 2007).

Fertilization

Given the importance of nutrient availability to corn agronomic performance, fertilization

with nitrogen, phosphorus, and potassium is practiced widely (Ritchie et al., 2008). In 2005

(the date of the last USDA Agricultural Chemical Usage Summary to include corn),

fertilizers were applied to 96% of corn acreage in 19 reported states (USDA-NASS, 2006). In 

a 2010 survey of program states, the USDA-NASS reported that nitrogen was applied to 97% of 

the corn acreage at an average of 140 pounds per acre (lb/acre); phosphate was applied to 78% 

of corn acreage at an average rate of 60 lb/acre; and potash was applied to 61% of corn acreage 

at a rate of 79 lb/acre (Table 2.(USDA-NASS, 2011a).

15
Table 2-1: Corn: total fertilizer primary nutrient applications, 2010.

Primary 

Nutrient

Area Applied

(percent)

Applications

(number)

Rate per 

Application

(pounds per 

acre)

Rate per 

Crop Year

(pounds per 

acre)

Total

Applied

(million 

pounds)

Nitrogen 97 1.8 78 140 11,030.9

Phosphate 78 1.2 52 60 3,800.4

Potash 61 1.2 73 79 3,943.5

Sulfur 15 1.2 11 13 166.5

Source: (USDA-NASS, 2011a).

1 Program states surveyed – Colorado, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, 

Missouri, Nebraska, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Texas, and 

Wisconsin.

Pesticides

Pesticide use, including both insecticides and herbicides, is common in corn 

production. In 2010, approximately 12% of the corn-planted acreage was treated with 

insecticides, with the most frequently applied (listed in order of total pounds applied) 

being chlorpyrifos for corn rootworm and earworms and European corn borer (1% of the 

acreage, with total applications of approximately 478,000 pounds), tefluthrin for control 

of corn rootworm (3% of the acreage, with total applications of 242,000 pounds), and 

tebupirimphos for corn rootworm and seed corn maggot (2% of the acreage, with total 

applications of 195,000 pounds (USDA-NASS, 2011a), Table 2.2).

Table 2-2: Corn: total insecticide applications, 2010. 

Insecticide Area 

Applied

(percent)

Applications

(number)

Rate per 

Application

(pounds per 

acre)

Rate per 

Crop Year

(pounds per 

acre)

Total 

Applied

(thousand

pounds)

Bifenthrin 2 1 0.039 0.039 86

Chlorpyrifos 1 1 0.857 0.875 478

Cyfluthrin 2 1 0.008 0.008 15

Dimethoate <0.5 1.1 0.481 0.513 52

16
Lambdacyhalothrin 2 1 0.016 0.017 24

Permethrin 1 1 0.13 0.13 72

Propargite <0.5 1 1.721 1.721 109

Spiromesifen <0.5 1.2 0.194 0.224 59

Tebupirimphos 2 1 0.111 0.111 195

Tefluthrin 3 1 0.115 0.116 242

Terbufos <0.5 1 0.722 0.722 137

Zeta-cypermethrin <0.5 1 0.007 0.007 2

Source: (USDA-NASS, 2011a).

1 Program states surveyed – Colorado, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, 

Missouri, Nebraska, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Texas, and 

Wisconsin.

Although it is generally agreed that insecticide use in U.S. crops has decreased since 

the introduction of GE insect-resistant crops, the long-term trends related to herbicide

use resulting from the utilization of GE technologies are the subject of much debate

(Benbrook, 2009b; Fernandez-Cornejo et al., 2009; Brookes and Barfoot, 2010). 

Benbrook has reported that the adoption of herbicide-resistant crops has resulted in an

increase in the volume of herbicides applied to crops (Benbrook, 2009b). Benbrook

notes that herbicide use declined between 1996 and 2001 apparently in direct response 

to the adoption of herbicide-resistant crops; however, since that time, herbicide use has

increased (Benbrook, 2009b). Reported increases in herbicide use during the last 

decade reflect an increase in glyphosate applications as more glyphosate-resistant

crops are planted and an associated increase in use of other herbicides used to control 

glyphosate-resistant weeds (Benbrook, 2009b). Others report a continuing decline in 

herbicide use with the adoption of GE crops (Fernandez-Cornejo and Caswell, 2006) and 

in the amount of herbicide active ingredients applied to corn (Brookes and Barfoot, 

2010). The contradictory findings have been attributed to the different measurement 

approaches used by researchers, the manner in which different factors affecting pesticide 

use such as weather or cropping patterns are controlled for, and how collected data is 

statistically analyzed (NRC, 2010a). 

In 2012, approximately 21% of corn planted in the U.S. possessed resistance to only an

herbicide trait that was conferred through biotechnology and another 5 2 % 

were stacked with other traits including herbicide resistance and insect resistance

(Table 2.4:(USDA-NASS, 2012a)). The primary herbicide resistance trait in use has

been glyphosate resistance, and the adoption of this trait in other major crops, such as

cotton and soybean, is even higher (USDA-APHIS, 2012a). Weed resistance to

herbicides is a concern in agricultural production and the wide-spread adoption of

17
herbicide-resistant crops, especially GE-derived glyphosate-resistant crops, has

dramatically changed the approach that farmers take to avoid yield losses from weeds, 

(Gianessi, 2008; Duke and Powles, 2009).

Herbicides were applied to 98% of corn acreage in 2010, with the following four

herbicides identified as the most commonly applied: atrazine (61% of the acreage,

51.1 million pounds applied), glyphosate (68% of the acreage, 64.3 million pounds),

s-metolachlor (23% of the acreage, 21.8 million pounds), and acetochlor (25% of the

acreage, 27.9 million pounds) (USDA-NASS, 2011a) summarized in Table 2.3. The

relationship of these herbicide treatments to the adoption of GE varieties is illustrated

in Table 2.4 below, which presents the percentage of acres of herbicide-resistant and 

insect-resistant corn varieties cultivated in 2012. The data on this table suggest that 

approximately 73% of the total corn acreage in the U.S. was an herbicide resistant hybrid 

(HT + Stacked hybrids).

Table 2-3: Corn: total herbicide applications, 20101. 

Herbicide

Area 

Applied

(percent)

Applications

(number)

Rate per 

Applica--

tion

(pounds 

per acre)

Rate per 

Crop 

Year

(pounds 

per acre)

Total 

Applied

(thousand 

pounds)

2,4-D, 2-EHE 4 1.1 0.39 0.437 1,479

2,4-D, BEE 1 1.6 0.308 0.504 286

2,4-D, dimeth. salt 4 1 0.366 0.379 1,147

2,4-D, isoprop. salt -- 1.3 0.069 0.086 24

Acetochlor 25 1 1.392 1.398 27,921

Acifluorfen, sodium 1 1 0.043 0.043 21

Alachlor -- 1 1.225 1.232 412

Atrazine 61 1.1 0.946 1.034 51,129

Carfentrazone-ethyl -- 1 0.011 0.011 4

Clopyralid 5 1 0.088 0.089 328

Dicamba -- 1 0.126 0.126 23

Dicamba, digly. salt 1 1 0.194 0.194 134

Dicamba, dimet. salt 2 1.2 0.209 0.249 480

18
Herbicide

Area 

Applied

(percent)

Applications

(number)

Rate per 

Applica--

tion

(pounds 

per acre)

Rate per 

Crop 

Year

(pounds 

per acre)

Total 

Applied

(thousand 

pounds)

Dicamba, pot. salt -- 1.7 0.246 0.145 116

Dicamba, sodium 

salt 3 1.1 0.088 0.097 245

Diflufenzopyrsodium 2 1.1 0.035 0.04 79

Dimethenamid 1 1 0.986 1.02 520

Dimethenamid-P 5 1.1 0.593 0.63 2,603

Flufenacet 1 1 0.329 0.329 280

Flumetsulam 5 1 0.033 0.034 125

Foramsulfuron -- 1 0.029 0.029 9

GlufosinateAmmonium 2 1 0.296 0.298 515

Glyphosate 7 1.1 0.843 0.931 5,255

Glyphosate amm. 

salt 1 1.1 0.09 0.095 46

Glyphosate iso. salt 66 1.3 0.824 1.065 57,536

Glyphosate pot. salt 2 1.3 0.936 1.204 1,522

Halosulfuron -- 1.1 0.017 0.019 3

Isoxaflutole 7 1 0.065 0.066 399

Linuron -- 1 1.356 1.356 206

MCPA, sodium slat -- 1 0.427 0.427 173

Mesotrione 17 1 0.116 0.121 1,693

Metolaclor 1 1 1.234 1.276 546

19
Herbicide

Area 

Applied

(percent)

Applications

(number)

Rate per 

Applica--

tion

(pounds 

per acre)

Rate per 

Crop 

Year

(pounds 

per acre)

Total 

Applied

(thousand 

pounds)

Nicosulfuron 2 1 0.016 0.016 29

Paraquat 1 1.1 0.641 0.699 468

Pendimethalin 1 1 1.154 1.154 1,385

Primisulfuron -- 1 0.023 0.023 5

Prosulfuron -- 1 0.008 0.008 1

Rimsulfuron -- 1.1 0.014 0.015 48

S-Metolachlor 23 1.1 10.76 1.159 21,831

Saflufenacil 1 1.3 0.059 0.075 40

Simazine 2 1.1 1.038 1.169 2,196

Tembotrione 2 1 0.064 0.064 103

Thiencarbazonemethy 2 1 0.025 0.025 41

Thifensulfuron 2 1 0.007 0.007 11

Topramezone 1 1 0.014 0.014 9

Trifluralin 1 1 0.608 0.608 257

Source: (USDA-NASS, 2011a).

1 Program states surveyed - Colorado, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, 

Missouri, Nebraska, New York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Texas, and 

Wisconsin.

20
Table 2-4: Percentage of Herbicide-resistant, Insect-resistant, Stacked Trait, Total GE Corn, and

Total Corn Acreage Planted in Select States in 2012.

State Herbicideresistant (%)

Insectresistant

(Bt)

(%)

Stacked

(%)

Total

GE (%)

Total Corn

Acreage

(1,000

acres)

Indiana 15 9 60 84 6,200

Illinois 18 14 53 85 13,000

Iowa 15 12 64 91 14,000

Kansas 19 20 51 90 4,700

Michigan 26 8 52 86 2,600

Minnesota 22 19 47 88 8,700

Missouri 20 18 48 86 3,600

Nebraska 20 16 55 91 9,900

North 

Dakota 36 17 43 96 3,400

Ohio 20 13 43 76 3,900

South 

Dakota 23 9 62 94 6,000

Texas 21 20 44 85 1,900

Wisconsin 23 10 53 86 4,350

Total U.S. 21 15 52 88 96,450

Source: (USDA-NASS, 2012a).

Introduction of herbicide-resistant corn varieties, in particular glyphosate-resistant corn, 

has not significantly affected corn acreage managed with total herbicide application 

(Table 2.4). Herbicide application trends are presented in Table 2.5. While the 

applications of atrazine and acetochlor in corn have been relatively stable, application 

rates for glyphosate have increased. There are several reasons for the success of 

glyphosate in the market and the corresponding market sector penetration of glyphosateresistant crops since their introduction in the mid-late 1990s. Glyphosate 1) works non21
selectively on a wide range of plant species; 2) is a relatively low-cost herbicide; 3) 

enhances ‘no-till’ farming practices; and 4) has minimal animal toxicological and 

environmental impact (USDA-APHIS, 2012a). 

Table 2-5 Percent of U.S. corn acres1 treated with herbicides in 1995, 2000, 2005 and 2010.

Herbicide

Percent Corn Acres Treated

Herbicide

Percent Corn Acres Treate

1995 2000 2005 2010 1995 2000 2005 201

2,4-D2 13 8 3 4 Glyphosate 

Ammonium Salt -- -- -- 1

2,4-D, 2-EHE --3 -- 3 4 Glyphosate Iso. Salt -- -- 31 66

2,4-DB -- -- -- 1 Glyphosate Potassium 

Salt -- -- -- 2

2,4-D, Isopropyl salt -- -- 1 -- Halosulfuron 1 -- 1 --

Acetochlor 18 25 23 25 Imazapyr -- 2 1 --

Acifluorfen, Sodium -- -- -- 1 Imazaquin 15 -- -- --

Alachlor 8 4 1 -- Imazethapyr 1 3 1 --

Atrazine 65 68 66 61 Isozaflutole -- 3 6 7

Bentazon 2 2 -- -- MCPA Sodium Salt -- -- 1 --

Bromoxynil 8 4 1 -- Mesotrione -- -- 20 17

Butylate 1 -- -- -- Metolachlor 29 12 2 1

Carfentrazone-ethyl -- 1 -- -- Metribuzin 1 2 -- --

Clopyralid -- 9 5 5 Nicosulfuron 13 15 10 2

Cloransulam -- -- 1 -- Paraquat 1 1 1 1

Cynazine 17 -- -- -- Pendimethalin 4 3 2 1

Dicamba 27 21 1 -- Primisulfuron 3 9 2 --

Dicamba Digly. Salt -- -- 2 1 Prosulfuron -- 4 1 --

Dicamba Dimet. Salt -- 3 3 2 Pyridate -- 5 -- --

22
Dicamba Pot. Salt -- 5 2 -- Rimsulfuron 1 9 8 4

Dicamba Sodium 

Salt -- -- 4 3 Saflufenacil -- -- -- 1

DiflufenzopyrSodium -- 3 4 2 S-Metolachlor -- 16 23 23

Dimethenamid 3 7 1 1 Simazine 3 2 3 2

EPTC 3 1 -- -- Sulfosate -- -- 1 --

Fluazifop -- 3 -- -- Tembotrione -- -- -- 2

Flufenacet -- 2 3 1 Thiencarbazone-methy -- -- -- 2

Flumetsulam 1 10 6 5 Thifensulfuron 1 -- -- 2

Foramsulfuron -- -- 2 -- Topramezone -- -- -- 1

GlufosinateAmmonium 2 -- 5 2 Trifluralin -- -- 1 1

Glyphosate 6 9 2 7

Source (USDA-NASS, 2011a)).

1 Survey states:

1995: Delaware, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, 

North Carolina, Ohio, Pennsylvania, South Dakota, Texas, and Wisconsin.

2000: Colorado, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New York, 

North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Texas, and Wisconsin.

2005: Colorado, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New 

York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Texas, and Wisconsin.

2010: Colorado, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Nebraska, New 

York, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Texas, and Wisconsin.

2 Dimethylamine salt formulation of 2,4-D

3 -- = No value

Increased selection pressure resulting from the wide-spread adoption of glyphosateresistant crops, along with the reductions in the use of other herbicides and weed 

management practices, has resulted in both weed population shifts and increasing 

glyphosate resistance among some weed populations (Owen, 2008; Duke and Powles, 

2009). To deter this trend and to avoid decreased crop yields resulting from weed 

competition, growers adapt weed management strategies, including the use of herbicides 

with alternative modes of action (Genective, 2012). Alternative modes of action in this 

case refer to herbicides which are different with respect to how they act on the plant 

physiology. Some common modes of herbicide action include chloroacetamide class

23
(acetochlor, metolachlor), HPPD-inhibitors (mesotrione), photosystem-II inhibitors or 

triazines (atrazine), auxin growth regulators (2,4-D), sulfonylureas or acetolactate 

synthase inhibitors (nicosulfuron), or amino acid inhibitors (glyphosate), (Ross and 

Childs, 2011). The practice of consistently using herbicides with alternative modes of 

action instead of reliance primarily on glyphosate could potentially diminish the 

populations of glyphosate-resistant weeds and reduce the likelihood of the development 

of new herbicide-resistant weed populations (Dill et al., 2008; Duke and Powles, 2008; 

Owen, 2008; Duke and Powles, 2009; Genective, 2012). 

The emergence of resistance to herbicides is not exclusive to glyphosate-resistant crops 

and corresponding weedy species. Tables 2.6 through 2.9 lists those weedy species 

which have been identified as herbicide-resistant in at least some part of their range. The 

emergence of herbicide resistance presents continued challenges to growers to understand 

which herbicide-resistant species is present and the best agronomic practice available to 

manage the weed. 

Table 2-6: U.S. Chloroacetamide-resistant Weeds through December 2012

Scientific Name Common Name Year Identified

Lolium multiflorum Italian Ryegrass 2005 

Source: (Heap, 2012).

Table 2-7: U.S. 4-HPPD Inhibitor-resistant Weeds through December 2012

Scientific Name Common Name Year Identified

Amaranthus tuberculatus (syn. rudis) Common Waterhemp 2009 

Source: (Heap, 2012).

Table 2-8: Photosystem II Inhibitor-resistant Weeds through December 2012

Scientific Name Common Name Year Identified

Abutilon theophrasti Velvetleaf 1984

Amaranthus hybridus Smooth Pigweed 1972

Amaranthus palmeri Palmer Amaranth 1993

Amaranthus powellii Powell Amaranth 1977

Amaranthus retroflexus Redroot Pigweed 1980

24
Amaranthus tuberculatus (syn. 

rudis)

Common Waterhemp 1994

Ambrosia artemisiifolia Common Ragweed 1976

Atriplex patula Spreading Orach 1980

Capsella bursa-pastoris Shepherd's-purse 1984

Chenopodium album Lambsquarters 1973

Chenopodium strictum var. 

glaucophyllum

Late Flowering Goosefoot 1976

Chloris inflata Swollen Fingergrass 1987

Conyza canadensis Horseweed 1981

Datura stramonium Jimsonweed 1992

Echinochloa crus-galli Barnyardgrass 1978

Eleusine indica Goosegrass 2003

Kochia scoparia Kochia 1976

Poa annua Annual Bluegrass 1978

Polygonum pensylvanicum Pennsylvania Smartweed 1990

Polygonum persicaria Ladysthumb 1980

Portulaca oleracea Common Purslane 1991

Senecio vulgaris Common Groundsel 1970

Setaria faberi Giant Foxtail 1984

Setaria glauca Yellow Foxtail (glauca) 1981

Solanum ptycanthum Eastern Black Nightshade 2004

Source: (Heap, 2012).

25
Table 2-9: U.S. Glyphosate-resistant Weeds through December 2012

System Scientific Name Common Name Year Identified

Weeds identified outside of 

Roundup Ready® Systems

Lolium rigidum Rigid Ryegrass 1998

Conyza bonariensis Hairy Fleabane 2003

Weeds identified in Roundup 

Ready® Systems

Poa annua Annual Bluegrass 2010

Kochia scoparia Kochia 2007

Ambrosia 

artemisiifolia

Common Ragweed 2004

Ambrosia trifida Giant Ragweed 2004

Eleusine indica Goosegrass 2010

Conyza canadensis Horseweed, 

Marestail

2000

Amaranthus palmeri Palmer Amaranth 2005

Amaranthus rudis Common 

Waterhemp

2005

Lolium multiflorum1 Italian Ryegrass 2001

Echinochloa colona Junglerice 2008

Sorghum halepense Johnsongrass 2005

Source: (Heap, 2012).

Weed management strategies need to be carefully planned to integrate appropriate 

technologies into an economic level of control (Shaw et al., 2011). A diverse strategy is 

essential to reduce selection pressure on the weed population (Powles and Preston, 2009). 

Such an integrated weed management approach should combine: 

• Rotation of crops – to allow a more varied weed control program 

• Rotation of cultural practices – to reduce reliance on herbicides 

• Rotation of sequences and mixtures of herbicidal modes of action and chemistry –

to reduce the pressure on a specific herbicide group (Powles and Preston, 2009). 

Monsanto, the developer of glyphosate, includes the following strategies to advise

growers in managing the risk of weed resistance (Monsanto, 2011b):

• Scout fields before and after herbicide application. 

• Start with a clean field, using either a burn-down herbicide application or tillage. 

• Control weeds early when they are relatively small. 

• Rotate herbicides that have different modes of action. 

• Use residual herbicides that have different modes of action. 

• Use tank-mixes of herbicides that have different modes of action. 

• Incorporate other herbicides and cultural practices as part of glyphosate resistant

cropping systems where appropriate. 

• Use the right herbicide product at the right rate and the right time. 

• Control weed escapes and prevent weeds from setting seeds. 

• Clean equipment before moving from field to field to minimize spread of weed 

26
seed. 

• Use new commercial seed as free from weed seed as possible. 

• Report any incidence of repeated non-performance on a particular weed to the 

local crop protection chemical company representative, retailer, or county 

extension agent. 

2.1.3 Organic Corn Production

In the U.S., only products produced using specific methods and certified under the 

USDA’s Agricultural Marketing Service (AMS) National Organic Program (NOP) 

definition of organic farming can be marketed and labeled as “organic” (USDA-AMS, 

2010). Organic certification is a process-based certification, not a certification of the end 

product; the certification process specifies and audits the methods and procedures by 

which the product is produced.

In accordance with NOP, an accredited organic certifying agent conducts an annual 

review of the certified operation’s organic system plan and makes on-site inspections of 

the certified operation and its records. Organic growers must maintain records to show 

that production and handling procedures comply with USDA organic standards. 

The NOP regulations preclude the use of excluded methods. The NOP provides the 

following guidance under 7 CFR Section 205.105:

...to be sold or labeled as “100 percent organic”, “organic” or “made with organic 

(specified ingredients or group(s)),” the product must be produced and handled 

without the use of...:

(a) Synthetic substances and ingredients...

(e) Excluded methods...

Excluded methods are then defined at 7 CFR Section 205.2 as:

A variety of methods used to genetically modify organisms or influence 

their growth and development by means that are not possible under 

natural conditions or processes and are not considered compatible with 

organic production. Such methods include cell fusion, 

microencapsulation and macroencapsulation, and recombinant DNA 

technology (including gene deletion, gene doubling, introducing a foreign 

gene, and changing the positions of genes when achieved by recombinant 

DNA technology). Such methods do not include the use of traditional 

breeding, conjugation, fermentation, hybridization, in vitro fertilization, 

or tissue culture.

Organic farming operations, as described by the NOP, are required to have distinct, 

defined boundaries and buffer zones to prevent unintended contact with excluded 

methods from adjoining land that is not under organic management. Organic production 

operations must also develop and maintain an organic production system plan approved 

by their accredited certifying agent. This plan enables the production operation to 

27
achieve and document compliance with the National Organic Standards, including the 

prohibition on the use of excluded methods (USDA-AMS, 2010).

Common practices organic growers may use to exclude GE products include planting 

only organic seed, planting earlier or later than neighboring farmers who may be using 

GE crops so that the crops will flower at different times, and employing adequate 

isolation distances between the organic fields and the fields of neighbors to minimize the 

chance that pollen will be carried between the fields (NCAT, 2003). Although the 

National Organic Standards prohibit the use of excluded methods, they do not require 

testing of inputs or products for the presence of excluded methods. The presence of a 

detectable residue of a product of excluded methods alone does not necessarily constitute 

a violation of the National Organic Standards (USDA-AMS, 2010). The current NOP 

regulations do not specify an acceptable threshold level for the adventitious presence of 

GE materials in an organic-labeled product. The unintentional presence of the products 

of excluded methods will not affect the status of an organic product or operation when 

the operation has not used excluded methods and has taken reasonable steps to avoid 

contact with the products of excluded methods as detailed in their approved organic 

system plan (Ronald and Fouche, 2006; USDA-AMS, 2010).

Although conventional corn yields tend to be higher than organic yields, net returns from 

organic acres continues to be greater than net return from conventional acres, with a 16% 

premium received for organic growers reported in 2008 (Kuepper, 2002; Coulter et al., 

2010; Roth, 2011). Certified organic corn acreage is a relatively small percentage of 

overall corn production in the U.S. The most recently available data show 194,637 acres 

of certified organic corn production in 2008 (Table 6; (USDA-ERS, 2011h). This is 

0.16% of the 93.6 million acres of corn planted in 2008 (Table 3; (USDA-ERS, 2011h).

2.2 Physical Environment

2.2.1 Water Resources

Corn is a water sensitive crop with a low tolerance for drought. The stress response and 

yield loss depends on the stage of the corn growth (Farahani and Smith, 2011). Corn 

requires approximately 4,000 gallons through the growing season to produce 1 bushel of 

grain (NCGA, 2007a). The water demand is variable over the growing season, with the 

greatest water demand during the silk production stage in mid-season. During this stage, 

the water requirement is estimated at approximately two inches of water per week (or 0.3 

inches per day) (Heiniger, 2000; Farahani and Smith, 2011).

This water demand is met by a combination of natural rainfall, stored soil moisture from 

precipitation before the growing season, and supplemental irrigation during the growing 

season (Heiniger, 2000; Farahani and Smith, 2011). Groundwater is the major source of 

water for irrigation and is used on almost 90% of irrigated corn acreage in the U.S.

(Christensen, 2002). Corn for grain has substantially more irrigated area than any other 

single crop in the U.S. (Christensen, 2002). In 2007, 13.0 million U.S. corn acres were 

irrigated, representing 15% of all corn acres harvested for grain (USDA-NASS, 2009). 

28
Non-point source (NPS) pollution is the primary source of pollutant discharge to rivers 

and lakes (US-EPA, 2003). Agricultural management practices that contribute to NPS 

pollution include the type of crop cultivated, plowing and tillage, and the application of 

pesticides, herbicides, and fertilizers. The EPA lists the most frequent cause of 

impairment in assessed streams and rivers from all sources as pathogens, with sediment 

second, and nutrients third; pesticides are only the 16th most important (US-EPA, 

2012b). The primary cause of agricultural NPS pollution, however, is increased 

sedimentation in surface waters following soil erosion (US-EPA, 2005). The major 

contribution to groundwater contamination derives from agricultural areas (nitrogen 

inputs from fertilizer and manure) and is influenced by regional environmental factors 

such as precipitation and soil characteristics (US-EPA, 2003). Nutrients in excess are 

listed as the second cause of impairment in lakes, reservoirs, and ponds, with agriculture 

listed as the third most probable source of the impairment (US-EPA, 2012b).

Agricultural pollutants released by soil erosion include sediments, fertilizers, and 

pesticides that are introduced to area lakes and streams when they are carried off of fields 

by rain or irrigation waters (US-EPA, 2005). Increase in sediment loads to surface waters 

can directly affect fish, aquatic invertebrates, and other wildlife maintenance and 

survival. It also reduces the amount of light penetration in water which directly affects 

aquatic plants. Indirectly, soil erosion-mediated sedimentation can increase fertilizer 

runoff, facilitating higher water turbidity, algal blooms, and oxygen depletion (US-EPA, 

2005). 

Because of its low mobility in soil, the potential for glyphosate leaching to groundwater 

is low and its potential movement to surface waters at high levels is considered low (USEPA, 2009f); however, glyphosate can enter surface and subsurface waters if used in 

close proximity to water bodies or by runoff from terrestrial applications (WHO, 2005). 

In water, glyphosate adsorbs to suspended organic and mineral matter and is broken 

down primarily by microorganisms. In aerobic water, sediment glyphosate has a residual 

half-life of 7 days, but in anaerobic aquatic sediment settings its residual half-life is 

approximately 208 days (US-EPA, 2009f). Surfactants may be used with glyphosate 

because the latter is highly soluble in water and will easily drip off plant surfaces (USEPA, 2009f). 

Coupe et al (2011) recently evaluated the fate of glyphosate and its AMPA degradate on 

a watershed scale in three Mississippi River basin watersheds and compared results to a 

watershed in France. They found from 0.06 to 0.86% of glyphosate was transported to 

surface water, although their samples frequently detected both glyphosate and AMPA 

(Coupe et al., 2011). Variability was correlated to differences in source strength, rainfall 

runoff, and flow route. The study concluded the watersheds most at risk for transport of 

glyphosate have high application rates, rainfall events resulting in overland runoff, and 

flow routes unfiltered by soil. Glyphosate has not been identified as the cause of 

impairment to any water bodies classified as such under Section 303(d) of the CWA (USEPA, 2011d).

Conservation tillage and no-till practices have been shown to minimize soil erosion and 

runoff to surface water. This is discussed more fully in the following section. 

29
2.2.2 Soil Quality

Corn is cultivated in a wide variety of soils across the U.S. (see, e.g., Corn Crop Profiles, 

(IPM-Centers, 2013)). The timing for corn planting is variable, but generally starts when 

soil temperatures reach 50°F (IPM, 2004; IPM, 2007). 

Conventional corn tillage traditionally requires that the producer remove all plant 

residues and weeds from the soil surface prior to planting (primary and secondary 

tillage), and then continue with shallow tillage to cultivate the soil while the crop is 

growing to control late emerging weeds (Hoeft et al., 2000a; NCGA, 2007b). This 

practice results in soil loss to wind and water erosion (NCGA, 2007b). 

Conservation practices, including conservation tillage, have been developed to reduce 

field tillage and thus reduce the corresponding soil loss (USDA-NRCS, 2006c). By 

definition, conservation tillage leaves at least 30% of the soil covered by crop residue 

(Peet, 2001). The new crop is planted into the plant residue or in narrow strips of tilled 

soil. This is in comparison to conventional tillage where the seedbed is prepared through 

plowing (to turn the soil surface over), disking (to reduce the size of soil clods created by 

plowing), and harrowing (to reduce the size of clods left by disking) (Peet, 2001). 

Benefits of reduced tillage practices include retention of soil organic matter and 

beneficial insects, increased soil water-holding capacity, less soil and nutrient loss from 

the field, reduced soil compaction, and less time and labor required to prepare the field 

for planting (Peet, 2001). 

Corn cultivation using conservation tillage practices can result in as much as 50% soil 

cover as residue following harvest (Werblow, 2007). This land cover aids in maintaining 

soils (Werblow, 2007). Other conservation measures successfully used on corn acres 

include contour farming, grass buffered drainageways, terraces, and retention/detention 

ponds (NCGA, 2007b). Increases in total acres dedicated to conservation tillage have 

been attributed to an increased use of herbicide-resistant GE seed which eliminates the 

need for mechanical weed control (Towery and Werblow, 2010b) (USDA-NRCS, 2006b)

and direct survey of grower’s tillage methods following glyphosate resistant seed use 

showed that corn growers increased adoption of conservation tillage; the percentage who 

already used these techniques was already high (Givens et al., 2009). Corn cultivation 

residues in a conservation tillage production system have been identified as causing cool, 

wet soils along with heavy residues which impede seeding or germination (Werblow, 

2007). These concerns can each be addressed through a number of corn cultivation 

techniques, including corn varieties developed to thrive in cool, wet soils; seed treatments 

for insect and disease control; selection of appropriate equipment to manage high-residue 

conditions; and judicious use of appropriate herbicides to control weeds remaining in the 

conservation tillage fields (NCGA, 2007c; Werblow, 2007). As noted in the discussion 

of Cropping Practices in Subsection 2.1.2, conservation tillage also has been identified as 

presenting potential disease management challenges for those growers cultivating cornto-corn (Robertson et al., 2009).

As reduced tillage practices are adopted, there is a corresponding increase in organic 

matter in soil. This helps bind soil nutrients resulting in significant reductions in the loss 

of cropland soil from runoff, erosion, and leaching over time (Leep et al., 2003; USDANRCS, 2006b; USDA-NRCS, 2006c; NCGA, 2007b; NCGA, 2007c). Total soil loss on 

30
highly erodible croplands and non-highly erodible croplands decreased from 462 million 

tons per year to 281 million tons per year or by 39.2% from 1982 to 2003 (USDA-NRCS, 

2006b). This decrease in soil erosion carries a corresponding decrease in non-point 

source surface water pollution of fertilizer and pesticides (NCGA, 2007b). The reduction 

in soil erosion also is attributed to a decrease in the number of acres of highly erodible 

cropland being cultivated (USDA-NRCS, 2006b).

Depending on the physical setting of the agricultural operation, conservation tillage may 

be required. Farmers, including corn growers, producing crops on highly erodible land 

are required by law to maintain a soil conservation plan approved by the USDA National 

Resources Conservation Service (NRCS) (USDA-ERS, 2012a). These soil conservation 

plans are prepared by the grower pursuant to the 1985 Food Security Act Conservation 

Compliance and Sodbuster programs to minimize soil erosion (USDA-ERS, 2012a). 

Corn farmers also are actively involved in state, local, and national programs that idle 

environmentally sensitive land from crop production, including the Conservation Reserve 

Program, the Conservation Reserve Enhancement Program, and the Farmable Wetlands 

Program (NCGA, 2007c). 

Pesticide use has the potential to affect soil quality due to impacts to the microbial 

community, and is discussed further in Subsection 2.3.4, Microorganisms. Glyphosate is 

rapidly and tightly adsorbed in soil; its adsorption rate is minimally influenced by organic 

matter, the amount of clay, silt, or sand, and pH, although soil high in phosphate 

decreases its adsorption (Senseman, 2007), making it more available for plant uptake, 

microbial degradation, and leaching (Kremer and Means, 2009). Glyphosate is 

microbially degraded in soil and water and the rate of decomposition varies with the 

microbial structure and population, having an average soil residual half-life of 47 days 

(Senseman, 2007). 

It has been reported that glyphosate appears to interact with manganese by forming 

insoluble, stable complexes that either immobilize this element, reducing plant uptake, or 

preventing reduction in the plant, making it unavailable (Eker et al., 2006; Neumann et 

al., 2006; Ozturk et al., 2008; Cakmak et al., 2009; Huber, 2010). These studies were not 

necessarily done on glyphosate resistant crop varieties, however, and most were not 

conducted in soil, but in nutrient solutions, and in a greenhouse. Huber (2010) and 

Cakmak et al. (2009) also reported that glyphosate is a broad-spectrum chelate of several 

other nutrients (e.g., iron, calcium, magnesium, copper, iron, nickel, and zinc); however, 

these assertions are not without debate. (Hartzler, 2010) agrees that glyphosate could 

immobilize essential elements temporarily, but offers that it does not specifically target 

manganese or any other particular element, but instead targets those cations that are most 

prevalent in the soil. Hartzler (Hartzler, 2010) also reports that areas in which 

glyphosate interactions with manganese nutrition are reported are also areas with known 

soil manganese deficiencies. (Camberato et al., 2010) points out that manganese 

deficiency is not a new phenomenon and is also associated with high pH, low moisture, 

or high levels of organic matter; furthermore, manganese deficiency is easily 

recognizable and can usually be resolved through foliar application(s) of manganese 

fertilizers. One field based report showed that glyphosate resistant lines showed no 

deficiencies of manganese compared to their near-isoline controls, but sometimes 

responded with greater yield to manganese treatment, but not consistently; glyphosate 

31
resistance does not consistently affect either manganese uptake or responsiveness 

(Loecker et al., 2010). More recent results also have shown that two applications of 

glyphosate in the field do not alter leaf mineral content of soybean six weeks after 

application at either nine or 12 weeks after planting (Duke et al., 2012).

2.2.3 Air Quality 

Air emissions from agricultural operations include smoke from agricultural burning, 

vehicle exhaust associated with equipment used in tillage and harvest, suspended soil 

particulates associated with tillage, pesticide drift from spraying, and nitrous oxide

emissions from the use of nitrogen fertilizer (Hoeft et al., 2000a; USDA-NRCS, 2006a; 

USDA-NRCS, 2006b; Aneja et al., 2009; US-EPA, 2011a). These agricultural activities 

individually have the potential to cause negative impacts to air quality.

Volatilization of fertilizers, herbicides, and pesticides from soil and plant surfaces also 

introduces these chemicals to the air. The USDA Agricultural Research Service (ARS) is 

conducting a long-term study to identify factors that affect pesticide levels in the 

Chesapeake Bay region airshed (USDA-ARS, 2011). This study determined that 

volatilization is highly dependent upon exposure of disturbed unconsolidated soils and 

variability in measured compound levels is correlated with temperature and wind 

conditions. Another ARS study of volatilization of certain herbicides after application to 

fields has found moisture in dew and soils in higher temperature regimes significantly 

increase volatilization rates (USDA-ARS, 2011). Glyphosate has a low vapor pressure 

and volatilization from soils is not considered an important dissipation mechanism (USEPA, 1993b).

Pesticide and herbicide spraying introduce air quality impacts from drift and diffusion. 

Drift is defined by the EPA as “the movement of pesticide through air at the time of 

application or soon thereafter, to any site other than that intended for application” (USEPA, 2000). Diffusion is gaseous transformation to the atmosphere (FOCUS, 2008). 

Factors affecting drift and diffusion include application equipment and method, weather 

conditions, topography, and the type of crop being sprayed (US-EPA, 2000). The EPA is 

currently evaluating new regulations for pesticide drift labeling and the identification of 

BMPs to control such drift (US-EPA, 2009e), as well as identifying scientific issues 

surrounding field volatility of conventional pesticides (US-EPA, 2010b).

Chang (2011) recently evaluated the occurrence and fate of glyphosate and its degradate 

AMPA in the atmosphere and rainfall in the Mississippi River basin. They found the 

frequency of glyphosate in the air and rain was similar to that of other commonly applied 

herbicides such as atrazine and metolachlor, but its concentration in rain was higher, 

primarily due to the widespread use of glyphosate for crop production in the region 

(Chang et al., 2011). AMPA in air was sampled at a range of <0.01 to 0.97 nanograms 

per cubic meter, initially lower in the application season and increasing as glyphosate 

degraded in soil to produce the metabolite; its incidence in rain was similar to that of 

glyphosate. The study also investigated the source of glyphosate in the air and found 

most occurred from spray application rather than volatilization or transport from 

windborne soil. Chang et al. Chang (2011) conclude up to 97% of glyphosate may be 

removed from the atmosphere by weekly rainfall greater than 30 millimeters (1.18 

inches).

32
Many of the conservation plans and practices being developed by corn growers to comply 

with the Conservation Compliance and Sodbuster programs have an air quality focus 

which target reductions in air emissions from agricultural operations (USDA-NRCS, 

2006a; US-EPA, 2013) . Practices to improve air quality include conservation tillage, 

residue management, wind breaks, road treatments, burn management, prunings 

shredding, feed management, manure management, integrated pest management, 

chemical storage, nutrient management, fertilizer injection, chemigation and fertigation 

(inclusion in irrigation systems), conservation irrigation, scrubbers, and equipment 

calibration (USDA-NRCS, 2006a; USDA-NRCS, 2006b)). Conservation tillage practices 

resulting in improved air quality include: fewer tractor passes across a field, thus 

decreasing dust generation and tractor emissions; and an increase in surface plant 

residues and untilled organic matter which physically hold the soil in place and reduce 

wind erosion (Baker et al., 2005; USDA-NRCS, 2006a)). The USDA has estimated that 

by 2006, the adoption of conservation management plans in the San Joaquin Valley of 

California had reduced air emissions by 34 tons daily, or more than 20% of the total

emissions attributed to agricultural practices (Baker et al., 2005; USDA-NRCS, 2006a)). 

2.2.4 Climate Change

Climate change represents a significant and lasting statistical change in climate 

conditions that may be measured across both time and space. As scientists and the public 

became more concerned with climate change and the impact that human-derived air 

pollutants were having on global temperature, the EPA identified CO2, methane (CH4), 

and nitrous oxide (N2O) as the key GHG effecting warming temperatures. While each of 

these gases occurs naturally in the atmosphere, human activity has significantly increased 

the concentration of these gases since the beginning of the industrial revolution. The 

level of human-produced gases accelerated even more so after the end of the Second 

World War, when industrial and consumer consumption flourished. With the advent of 

the industrial age, there has been a 36% increase in the concentration of CO2, 148% in 

CH4, and 18% in N2O (US-EPA, 2012a).

U.S. agriculture may influence climate change through various facets of the production 

process (Horowitz and Gottlieb, 2010) and conversion of land to agriculture. The major 

sources of GHG emissions associated with crop production are soil N2O emissions, soil 

CO2 and CH4 fluxes, and CO2 emissions associated with agricultural inputs and farm 

equipment operation (Adler et al., 2007; US-EPA, 2012a). Over the 20-year period of 

1990 to 2009, total emissions in the agriculture sector grew by 9.3%, and in 2009, this 

sector was responsible for 6.3% of total U.S. GHG emissions (US-EPA, 2012a). CH4

and N2O were the primary GHG emitted by agricultural activities. Emissions from 

intestinal (enteric) fermentation and manure management represent about 21% and 8% of 

total CH4 emissions from anthropogenic activities, respectively (US-EPA, 2012a). 

Agricultural soil management activities including fertilizer application and cropping 

33
practices were the largest source of N2O emissions, accounting for 68% of all U.S. N2O 

emissions (US-EPA, 2012a).

Emissions of GHG released from agricultural equipment (e.g., irrigation pumps and 

tractors) include carbon monoxide (CO), nitrogen oxides(N20), methane (CH4), reactive 

organic gases, particulate matter, and sulfur oxides (SOx) (US-EPA, 2011a). On-site C 

emissions from equipment can be reduced by 41% for some crops (i.e., wheat) when 

changing from conventional tillage to no-till systems and 33% in corn (Nelson et al., 

2009). Reduced tillage practices which increased from 1990 to 2004 resulted in 

reductions of C of 2.4 terragrams in total onsite and offsite C production from energy 

production (Nelson et al., 2009). Emission of carbon dioxide, a significant GHG gas is 

associated with several agricultural practices, including land use changes and subsequent

energy consumption changes. For example increases may occur when forested land is 

cleared and planted to row crops, or when perennial crops such as grassland are replaced 

by an annual crop (US-EPA, 2012a). Energy consumption and their waste gases from 

new production on these acres also increase CO2 production.

Tillage contributes to increased GHG because it releases carbon dioxide (CO2) to the 

atmosphere, and the exposure and oxidation of soil organic matter (Baker et al., 2005). 

On-site emissions from energy use can be reduced by 20% for some crops (i.e., wheat) 

when changing from conventional tillage to no-till systems (Nelson et al., 2009). 

Sequestration rather than emission can also differ substantially when comparing tillage 

systems. The difference between sequestered carbon associated with no till compared to 

that of conventional tillage corn of all production systems is a significant increase of 812 

g/m2 (West and Post, 2002).Crops each have different sequestration changes when no till 

is compared with conventional till, and the benefit for continuous corn production is 270 

g/m2 C over that of continuous soybean (West and Post, 2002).

The contribution of agriculture to climate change largely is dependent on the production 

practices employed to grow various commodities, the region in which the commodities 

are grown, and the individual choices made by growers. For example, emissions of 

nitrous oxide, produced naturally in soils through microbial nitrification and 

denitrification, can be influenced dramatically by fertilization, introduction of grazing 

animals, cultivation of nitrogen-fixing crops and forage (e.g., alfalfa), retention of crop 

residues (i.e., no-till conservation), irrigation, and fallowing of land (US-EPA, 2012a). 

These same agricultural practices can influence the decomposition of carbon-containing 

organic matter sequestered in soil, resulting in conversion to carbon dioxide and 

subsequent loss to the atmosphere (US-EPA, 2012a). Conversion of crop land to pasture 

results in an increase in carbon and nitrogen sequestration in soils (US-EPA, 2012a). 

The EPA has identified regional differences in GHG emissions associated with 

agricultural practices on different soil types, noting that carbon emission rates differ 

between mineral soils and organic soils (US-EPA, 2012a). Mineral soils contain from 1 

34
to 6% organic carbon by weight in their natural state; whereas organic soils may contain 

as much as 20% carbon by weight (US-EPA, 2011a; US-EPA, 2012a). In mineral soils, 

up to 50% of the soil organic carbon can be released to the atmosphere on the initial 

conversion; however, over time, the soil establishes a new equilibrium that reflects a 

balance between carbon inputs from decaying plant matter and organic amendments and 

carbon losses from microbial decomposition (US-EPA, 2011a; US-EPA, 2012a). Organic 

soils, with their depth and richness in carbon content, continue to release carbon to the 

atmosphere for a longer period of time (US-EPA, 2012a). The EPA has estimated that 

mineral soil-based cropland areas sequestered over 45.7 Tg CO2 Eq5 in 2008, as 

compared with carbon emissions from organic soil-based croplands of 27.7 Tg CO2 Eq 

(US-EPA, 2012a). The adoption of conservation tillage, particularly in the Midwest 

regions with mineral soil shows the highest rates of carbon sequestration (US-EPA, 

2012a).

Changes in agriculture-related GHG production will not be significant unless large 

amounts of crop plantings produce changes in measureable concentrations. Because this 

product will be similar to other glyphosate resistant hybrids, APHIS does not anticipate 

any additional acreage or changes in GHGs produced by VCO-01981-5 hybrids. 

Other agriculture related changes affect GHG production. The EPA has identified a net 

reduction of sequestration of carbon in soil over an 18-year time scale, which results from

a declining influence of the Conservation Reserve Program. The CRP had encouraged 

growers to take marginal lands out of production (US-EPA, 2012a). To a certain extent, 

the EPA also noted that adoption of conservation tillage resulted in increases in carbon 

sequestration on those croplands (US-EPA, 2012a). The highest rates of carbon 

sequestration in mineral soils occurred in the Midwest, which is the region with the

largest area of cropland managed with conservation tillage (US-EPA, 2012a). This is in 

contrast to the highest rates of emission which occur in organic soils notably in the 

southeastern coastal region, the areas around the Great Lakes, and the central and 

northern agricultural regions along the West Coast (US-EPA, 2012a). 

The adoption of GE herbicide-resistant crops such as VCO-01981-5 corn may result in 

continued adoption of conservation practices by growers. However, after APHIS has 

determined that a plant is no longer regulated under the plant pest provisions of the PPA 

or the regulations of Part 340, APHIS does not maintain control over where the crop is 

grown, the methods used to produce commodities, or the individual choices that growers 

make.

5 The global warming potential of greenhouse gases are measured against the reference gas CO2, and are 

reported as teragrams (or million metric tons) of CO2 Equivalent, expressed as Tg CO2 Eq.

35

 
One outcome of the potential effects of agricultural production on climate change is the 

potential effect of the climate change on agriculture itself. In response to climate change, 

the current range of weeds and pests of agriculture is expected to increase. Current 

agricultural practices will need to adapt in response to these changes in the ranges of 

weeds and pests of agriculture (Field et al., 2007). Climate change potentially also may 

provide a positive impact to agriculture in general. The Intergovernmental Panel on 

Climate Change (IPCC) predicts that potential climate change in North America may 

result in an increase in crop yield by 5-20% for this century (Field et al., 2007). 

However, this positive impact will not be observed across all growing regions. The IPCC 

report notes that certain regions of the U.S. will be impacted negatively because the 

available water resources may be reduced substantially. Note that the extent of climate 

change effects on agriculture is highly speculative. Nevertheless, North American 

production is expected to adapt to climate change impacts with improved cultivars and 

responsive farm management (Field et al., 2007).

2.3 Biological Resources

Corn production systems in agriculture are host to a variety of animal species. A number 

of insects feed on corn plants or prey upon other insects inhabiting cornfields and a full 

complex of six communities of insect species can be found associated with the crop 

(Robertson et al., 2012).Although cornfields are generally considered poor habitat for 

birds and mammals in comparison with uncultivated lands because of continual

disturbances associated with intense cultivation, the use of cornfields by birds and 

mammals is not uncommon (Vercauteren and Hygnostrom, 1993; Palmer et al., 2011). 

Conservation practices incorporated in corn cultivation have brought a positive impact to 

animal and plant communities through reduced tillage, more carefully controlled and 

targeted chemical placement (fertilizers and pesticides), and better control of irrigation 

systems. Many GE crop systems provide opportunities to optimize the introduction and 

implementation of these practices, and have the potential to create more of these benefits. 

For example, herbicide resistance in corn and other crops facilitates cultivation with 

minimal tillage required to control volunteers and weeds (Towery and Werblow, 2010b). 

This subsection provides an overview of the biotic community associated with cornfields 

and their surrounding landscapes.

2.3.1 Animal Communities

Mammals and Birds

Intensively cultivated lands, such as those used in corn production, provide less suitable 

habitat for wildlife use than that found in fallow fields or adjacent natural areas. As such, 

the types and numbers of animal species found in cornfields are less diverse by 

comparison. Cornfields, however, have been shown to provide both food and cover for 

wildlife, including a variety of birds as well as large and small mammals (Vercauteren 

and Hygnostrom, 1993; Palmer et al., 2011). Some birds and mammals use cornfields at 

various times throughout the corn production cycle for feeding and reproduction, but 

most of the birds and mammals that use cornfields are ground-foraging omnivores that 

36
feed on the corn remaining in the fields following harvest (Vercauteren and Hygnostrom, 

1993; Krapu et al., 2004; Palmer et al., 2011).

The types and numbers of birds that inhabit cornfields vary regionally and seasonally but 

for the most part the numbers are low (Patterson and Best, 1996). Most of the birds that 

utilize cornfields are ground foraging omnivores that feed on corn seed, sprouting corn, 

and the corn remaining in the fields following harvest. Bird species commonly observed 

foraging on corn include red-winged blackbird (Agelaius phoeniceus), horned lark 

(Eremophila alpestris), brown-headed cowbird (Molothrus ater), vesper sparrow 

(Pooecetes gramineus), ring-necked pheasant (Phasianus colchicus), wild turkey 

(Meleagris gallopavo), American crow (Corvus brachyrhynchos), and various grouse and 

quail species (Dolbeer, 1990; Patterson and Best, 1996; Mullen, 2011). Following 

harvest, it is also common to find large flocks of Canada geese (Branta canadensis), 

Snow geese (Chen caerulescens), Sandhill cranes (Grus canadensis), and other migratory 

waterfowl foraging in cornfields (Sparling and Krapu, 1994; Taft and Elphick, 2007; 

Sherfy et al., 2011). 

A variety of mammals forage on corn at various stages of production. For the most part, 

herbivorous and omnivorous mammals feed on the ear at different stages of growth. 

Large- to medium-sized mammals that are common foragers of cornfields include: 

white-tailed deer (Odocoileus virginianus), raccoon (Procyon lotor), feral pigs (Sus 

scrofa), and woodchuck (Marmota monax). The most notable of these is the white-tailed 

deer which often inhabit woodlots adjacent to cornfields and frequent these fields for 

both food and cover especially in mid-summer (Vercauteren and Hygnostrom, 1993). 

The effects of deer herbivory on cornfields have been well-documented. Cornfields are 

vulnerable to deer damage from emergence through harvest (Vercauteren and 

Hygnostrom, 1993), but any damage at the tasseling stage most directly impacts yield 

(Stewart et al., 2007). White-tailed deer are considered responsible for more corn 

damage than any other wildlife species (Stewart et al., 2007). 

In addition to deer, significant damage to corn by raccoons also has been documented 

(DeVault et al., 2007; Beasley and Rhodes, 2008). Corn has been shown to constitute up 

to 65% of the diet of raccoons during the late summer and fall (MacGowan et al., 2006). 

As with these larger mammals, small mammal use of cornfields for shelter and forage 

also varies regionally and includes (Stallman and Best, 1996; Sterner et al., 2003; Smith, 

2005):

• Deer mouse (Peromyscus maniculatus)

• Meadow vole (Microtus pennsylvanicus)

• House mouse (Mus musculus)

• Thirteen-lined ground squirrel (Spermophilus tridecemlineatus)

Throughout the U.S., the deer mouse is the most common small mammal in almost any 

agricultural field (Stallman and Best, 1996; Sterner et al., 2003). Deer mice feed on a 

wide variety of plant and animal matter depending on availability, but primarily feed on 

37
seeds and insects. Deer mice have been considered beneficial in agroecosystems because 

they consume both weed and insect pests (Smith, 2005).

The meadow vole feeds primarily on fresh grass, sedges, and herbs, and also on seeds and 

grains of field crops. Although the meadow vole may be considered beneficial for its role 

in the consumption of weeds, this vole can be a significant agricultural pest where 

abundant when it consumes seeds in the field. Meadow vole populations are kept in 

check by high intensity agriculture methods, including conventional tillage; this vole is 

often associated with the field edges where cover is found off the field as well as limited 

tillage agriculture and strip crops (Smith, 2005).

The lined ground squirrel feeds primarily on seeds of weeds and available crops, such as 

corn and wheat. This species has the potential to damage agricultural crops, although it 

also can be considered beneficial when eating pest insects, such as grasshoppers and 

cutworms (Smith, 2005).

Invertebrates

Invertebrate communities in cornfields represent a diverse assemblage of feeding 

strategies including herbivores, predators, crop-feeders, saprophages, parasites, 

pollinators, gall formers, and polyphages (Stevenson et al., 2002), Numerous insects 

and related arthropods perform valuable functions; they pollinate plants, contribute to 

the decay and processing of organic matter, reduce weed seed populations through 

predation, cycle soil nutrients, and attack other insects and mites that are considered 

to be pests. Although many arthropods in agricultural settings are considered pests, 

such as the European corn borer (Ostrinia nubilalis) and the corn rootworm 

(Diabrotica spp.)(Willson and Eisley, 2001), there are many beneficial arthropods 

which are natural enemies of both weeds and insect pests (Landis et al., 2005). Some 

of these beneficial species include the convergent lady beetle (Hippodamia 

convergens), carabid beetles, the caterpillar parasitoids (e.g., Macrocentrus cingulum), 

and the 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). 

2.3.2 Plant Communities

Surrounding Landscapes and Other Vegetation in Cornfields

Non-crop vegetation within cornfields is limited by the extensive cultivation and weed 

control programs practiced by corn farmers. Non-crop vegetation in cornfields is 

consequently generally associated with vegetative communities adjacent to these fields. 

Cornfields may be bordered by other field crops or by woodlands, hedgerows, 

rangelands, pasture and grassland areas. These plant communities may occur naturally or 

they may be managed for the control of soil and wind erosion.

Corn is generally cultivated as a monoculture. Weed control programs are essential 

components of corn cultivation and high yield production. Weed control ideally involves 

an integrated approach that includes herbicide use, crop rotation, weed surveillance, and 

38
weed monitoring (Farnham, 2001; IPM, 2004; IPM, 2007; Hartzler, 2008; University-ofCalifornia, 2009). Intensive use of any single weed management tactic can cause an 

ecological shift in the weed community as a result of selection pressure on weed

populations, with a corresponding greater prevalence of weed species that are not 

controlled (Shaw et al., 2011). When a crop like corn is cultivated year after year in the 

same fields, using the same cultivation practices, the likelihood is high that weed and pest 

species will increase in these fields and that agronomic inputs may need additional 

attention (Erickson and Lowenberg-DeBoer, 2005; Sawyer, 2007; Stockton, 2007; 

University-of-California, 2009; Shaw et al., 2011). Crop rotation should be an important 

component of a successful weed management program in corn (Ransom et al., 2004; 

Erickson and Lowenberg-DeBoer, 2005; Stockton, 2007; University-of-California, 2009; 

Owen et al., 2011). As discussed in Subsection 2.2.2.2, Crop Rotation, since 1991, 75% 

of planted corn acreage has been grown in some type of crop rotation (USDA-ERS, 

2010b). 

The types of weeds in and around a cornfield depend on the immediate area in which the 

corn is planted (IPM, 2004; IPM, 2007; University-of-California, 2009; Purdue, 2011). 

Data have been collected on weed population densities by species, crop yield and crop 

production system economics with the intent of providing growers with insights into the 

sustainability and profitability of diversified weed management programs (Shaw et al., 

2011). To assist growers in managing weeds, individual states, typically through their 

state agricultural extension service, list the prevalent weeds in corn crops in their area and 

the most effective means for their control (see, e.g., (IPM, 2004; IPM, 2007; Universityof-California, 2009). 

The use of herbicide-resistant corn provides several weed management advantages to the 

growers. Broad spectrum post-emergent herbicides such as glyphosate, provide control 

of weeds early in the cultivation cycle thereby minimizing competition in the fields and 

providing optimal conditions for corn growth (IPM, 2004; IPM, 2007; University-ofCalifornia, 2009). Application of over-the-top post-emergent broad spectrum herbicides 

to an herbicide-resistant crop allows the grower to decrease the overall use of herbicides 

before cultivation, reduce the use of soil-applied herbicides, and streamline field 

cultivation activities for weed control (Marra et al., 2002; O'Sullivan and Sikkema, 2004; 

Ransom et al., 2004). Glyphosate-resistant crops have been widely adopted because 

glyphosate is highly effective against many economically important weeds, thus 

simplifying weed management and facilitating the widespread adoption of no tillage 

systems (Owen et al., 2011). However, since the introduction of glyphosate-resistant

crops, the use of tank mixtures and sequential applications of herbicides with more than 

one mode of action has declined, as many growers relied exclusively on glyphosate for 

weed control (Weirich et al., 2011b). The over-reliance on herbicides for weed 

management and the lack of herbicide diversity impose intense selection pressure on 

weed populations, resulting in the evolution of herbicide resistance, including resistance 

to glyphosate (Wilson et al., 2011a). Collectively, the practices used in crop production 

will ultimately impart selection pressures upon the weed community, resulting in shifts in 

the relative importance of specific weeds. Agricultural practices with the most impact on 

weed composition and prevalence are tillage and herbicide regime (Owen, 2008). Weed 

shifts are illustrated by a previously unimportant weed achieving ecological dominance 

39
due to changes in production practices (e.g., Asiatic dayflower) or the evolution of an 

herbicide-resistant weed biotype resulting from uncritical herbicide-use practices (e.g., 

common waterhemp) (Owen, 2008; Ulloa and Owen, 2009). In aggressive tillage 

systems, weed diversity tends to decline and annual grasses and broadleaf plants are the 

dominant weeds, whereas, in no-till fields, greater diversity of annual and perennial weed 

species may occur (Baucom and Holt, 2009). 

As described in Subsection 2.1.2, Agronomic Practices, while there are numerous tactics 

that will provide weed management, herbicides have been the dominant approach in corn 

production (Gianessi and Reigner, 2007; Green and Owen, 2011). Herbicide resistance 

naturally evolves when a plant survives and reproduces after exposure to a dose of

herbicide usually lethal to the wild type, passing this ability down to its future 

generations (WSSA, 2008). Genetic variability, including herbicide resistance, is 

exhibited naturally in normal weed populations, although at very low frequencies. When 

only one herbicide is used year after year as the primary means of weed control,

herbicide-resistant plants can quickly reproduce and spread to dominate the plant (weed) 

population and seed bank (WSSA, 2011). With no change in weed control strategies, in 

time, the weed population may be composed of more and more resistant weeds (USNARA, 2010b). 

Currently, there are 396 herbicide-resistant weed biotypes that have been reported 

representing 210 species and infesting an estimated 670,000 fields globally (Heap, 2012). 

Weeds with evolved resistance to glyphosate have increased since the commercial 

introduction of the Roundup Ready® glyphosate-resistant crops in 1996 (Owen et al., 

2011; Heap, 2012). It should be noted, however, that the GE crop in this case, namely 

corn, did not directly cause the resistance to evolve as a result of introgression. In 

addition, there are no near-relative weeds that are compatible with corn that are capable 

of receiving resistance transgenes (Ellstrand et al., 1999). As of December 2012, there 

are 24 weed species with evolved resistance to glyphosate world-wide and 13 in the U.S. 

(Table 2.10) (Owen et al., 2011; Heap, 2012). In the U.S., it is estimated that 11 of the 

13 glyphosate-resistant weed species were identified in glyphosate-resistant crop systems 

and are widely distributed in regions where agriculture predominates. For example, 15 

states have from 2 to 7 weed species with evolved resistance to glyphosate (Table 2.11) 

(Heap, 2012). Table 2.11 illustrates how widespread herbicide-resistant weeds are in the 

U.S., as the same 15 states with glyphosate-resistant weeds have also identified at least 1 

weed species with resistance to 3 to 8 herbicide modes of action. 

Table 2-10: U.S. glyphosate-resistant weeds as of December 2012.

System Species Year 

Identified

Weeds identified outside 

of Roundup Ready®

Systems

Rigid Ryegrass (Lolium rigidum) 1998

Hairy Fleabane (Conyza bonariensis) 2003

40
Weeds identified in 

Roundup Ready® Systems

Annual Bluegrass (Poa annua) 2010

Common Ragweed (Ambrosia 

artemisiifolia)

2004

Common Waterhemp (Amaranthus 

rudis)

2005

Giant Ragweed (Ambrosia trifida) 2004

Goosesgrass (Eleusene indica) 2010

Horseweed, Marestail (Conyza 

canadensis)

2000

Italian Ryegrass (Lolium multiflorum) 2001

Johnsongrass (Sorghum halepense) 2005

Junglerice (Echinochloa colona) 2008

Kochia (Kochia scoparia) 2007

Palmer Amaranth (Amaranthus 

palmeri)

2005

Source: (Heap, 2012)

Many of the glyphosate-resistant weeds are agronomically important and dominant 

members of weed communities. For example, glyphosate-resistant Palmer pigweed 

(amaranth) is a major economic problem in the Southeast U.S., while glyphosate-resistant 

waterhemp is an economically important weed in Midwestern states (Culpepper et al., 

2006; Owen, 2008). Other glyphosate-resistant weeds of importance include giant 

ragweed, common lambsquarters, and horseweed (Owen, 2008; Owen et al., 2011). 

As described in Subsection 2.1.2, Agronomic Practices, the most effective weed 

management programs focus on the inclusion of diverse control tactics in addition to 

herbicides (Beckie, 2006b; Owen, 2011a; Owen, 2011b). Given that some weeds have 

evolved multiple resistances to several herbicide mechanisms of action, it is important 

that growers choose herbicides with diverse mechanisms of action to avoid intense 

selection from only one or a few herbicides. The key consideration to managing 

herbicide-resistant weeds is to ensure that the herbicides used continue to have efficacy 

on the target weeds. Managing weed species that have evolved multiple resistances can 

be challenging. In corn production where sufficient herbicide mechanisms of action 

typically are available, (Beckie and Reboud, 2009) recommend the use of herbicides in 

tank mixtures rather than to simply rotate herbicide modes of action. However, in a study 

of the efficacy of acetolactate synthase (ALS)-inhibitor mixtures, Wrubel and Gressel 

41
(Wrubel and Gressel, 1994) note that not all mixtures meet all the criteria for resistance 

management, and the use of mixtures for short-term economic benefit risks increasing 

widespread resistance to herbicides. Weed scientists recommend the use of an integrated 

systems approach of including science-based crop improvement and farm management 

tools developed over the last 60 years, and providing producers reasonable and attractive 

alternatives for effective weed (Owen et al., 2011; Sellers et al., 2011).

Table 2-11: U.S. states with more than one weed species with glyphosate resistance.

State Number of weed 

species with glyphosate 

resistance

Number of herbicide modes of 

action with at least one resistant 

weed species

Arkansas 6 8

California 4 8

Illinois 3 5

Indiana 4 3

Iowa 3 6

Kansas 5 5

Louisiana 2 5

Michigan 2 5

Minnesota 3 4

Mississippi 7 7

Missouri 6 5

North Carolina 2 6

Ohio 3 5

Tennessee 4 6

Virginia 2 4

Source: (Heap, 2012)

42
Corn as a Volunteer

In the United States, corn is not listed as a weed (Crockett, 1977; Muenscher, 1980), nor 

is it present in the Federal Noxious Weed List (7 CFR Part 3606

) (USDA-NRCS, 2010). 

Furthermore, corn is grown throughout the world without any report that it is a serious 

weed or that it forms persistent feral populations (Gould, 1968; OECD, 2003). Like many 

domesticated crops, corn seed from a previous year’s crop can overwinter and germinate 

the following year. Manual or chemical measures are often applied to remove these 

volunteers. The plants that are not removed do not typically result in feral populations in 

following years because maize is incapable of sustained reproduction outside of domestic 

cultivation (Gould, 1968). Corn possesses few of the characteristics of those plants that 

are notably successful as weeds (Baker, 1965; Keeler, 1989).

Corn periodically occurs as a volunteer when corn seeds remain in the field after harvest 

and successfully germinates (Beckett and Stoller, 1988; Davis, 2009; Hager, 2009; 

Bernards et al., 2010; Johnson et al., 2010; Wilson et al., 2010; Stewart, 2011; Wilson et 

al., 2011b; USDA-APHIS, 2012a). Post-harvest seed residues in fields can be a result of 

harvester inefficiency, bird dispersal or seed drop, with the seed ending up beyond the 

field margins or remaining as residues in the field after the harvest (Davis, 2009). This 

can be a particular problem when weather late in the season causes ears to drop or 

lodging to occur which places the ears on the ground where the seed then germinate the 

following year. Volunteer corn can be present as single plants or as clumps formed when 

an ear drops to the ground and is partially buried (Davis, 2009; Wilson et al., 2010). 

When those seeds survive to the subsequent growing season, volunteer plants may 

develop within subsequent crops or outside of the cropped area. The potential for corn, 

including GE corn to establish as a volunteer has been the subject of recent research, with 

a particular emphasis on yield impact and management of herbicide-resistant corn as a 

volunteer in subsequent crops modified for resistance to the same herbicide (Beckett and 

Stoller, 1988; Beckie and Owen, 2007; Davis, 2009; Wilson et al., 2010; Wilson et al., 

2011b).

Corn volunteers are limited by the geography in which they initially are planted. Corn 

generally does not overwinter in those regions where freezing temperatures are reached in 

the winter; however, corn seeds which are incorporated in the soil during harvest or in 

fall tillage may overwinter and grow the following spring (Stewart, 2011). Volunteer 

corn lacks vigor and competitiveness because the volunteer plant is two generations 

removed from the cross which produced the hybrid planted (Davis, 2009). For 

genetically-transformed corn plants that have escaped the cultivated field to produce a 

viable rogue population, off-field plants would need to inherit and express additional 

unrelated traits that provide selective advantage to a weedy growth habit. Some of these 

advantageous traits include having large numbers of easily dispersed seeds, a propensity 

to grow on disturbed ground, an enhanced vegetative propagation, and increased seed 

dormancy (US-EPA, 2010a). Some literature suggests that these traits do not exist within 

corn, a species that has been selected for domestication and cultivation under conditions 

not normally found in natural settings (US-EPA, 2010a). However, other literature 

6 http://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads/weedlist-2010doc.pdf

43

 
clearly notes that GE corn is a problematic volunteer the year after harvest in soybean, 

dry beans, sugar beets and subsequent corn Crops (Davis, 2009; Bernards et al., 2010; 

Johnson et al., 2010; Wilson et al., 2010; Stewart, 2011; Wilson et al., 2011b). For 

example, the presence of volunteer corn in soybeans was identified in 12% of the 

soybean acreage in Illinois in a 2005 survey of soybean acreage in corn – soybean 

rotation systems (Davis, 2009), and a 2010 survey of soybean cultivation in Illinois

identified a field with up to 500,000 corn plants per acre (Hager, 2010). 

Volunteer corn competes with the intended crop for light, soil moisture, and nutrients 

(Soltani et al., 2006; Bernards et al., 2010; Wilson et al., 2010). The effect of volunteer 

corn on the yields of the intended crop depends on the density of the volunteer corn 

(Davis, 2009; Bernards et al., 2010). In controlled agronomic studies, an analysis of 

yield impacts to soybeans from volunteer corn was evaluated at densities up to 17,800 

corn plants per acre of soybean (Alms et al., 2007; Alms et al., 2008). In these controlled 

studies, volunteer corn densities ranging from zero plants per square meter up to 4.4 

plants per square meter were cultivated in soybean, with corresponding soybean yield 

losses of up to 58% (Alms et al., 2007; Alms et al., 2008). Pre-harvest herbicide 

treatments of the volunteer corn reduced but did not eliminate the yield impacts. In 

experimental studies, volunteer corn in soybeans was controlled using different 

application rates of the herbicide clethodim in the attempt to better quantify soybean 

yield loss (Alms et al., 2008). Clethodim treatments of the volunteer corn did reduce the 

volunteer corn density, although even after a 98% control of the volunteer corn, soybean 

yield still suffered a 5% reduction in yield (Alms et al., 2008).

Successful control of corn volunteers, including herbicide-resistant varieties, is 

accomplished with the use of various combinations of cultivation practices and herbicides 

(Beckett and Stoller, 1988; Beckie and Owen, 2007; Sandell et al., 2009). Volunteer corn 

is less of a concern in no-till fields than in fall-tilled fields because of the lower 

probability that corn seed will survive and germinate in the following growing season 

(Bernards et al., 2010). In no-till fields, the fallen corn is frequently consumed by 

wildlife and also is subject to winter weather conditions (Bernards et al., 2010). In fall 

tillage systems, corn seed may be buried in the soil and overwinter, volunteer corn which 

has emerged from this overwintered seed requires control with spring tillage or with an 

application of herbicides (Bernards et al., 2010). 

The adoption of herbicide-resistant crops has changed the approaches which growers can 

use to reduce crop losses from corn volunteers (Beckie and Owen, 2007). In soybean 

fields cultivated in rotation with corn where the volunteer corn is glyphosate- or 

glufosinate-resistant, herbicides with alternate modes of action might be employed (e.g., 

glufosinate in LibertyLink® soybean to control a Roundup Ready® glyphosate-resistant

volunteer corn variety (Minnesota, 2009; Bernards et al., 2010). Post-emergent grass 

herbicide ACCase inhibitors also are recommended, including quizalofop, fluazifop, 

fenoxaprop, sethoxydim, and clethodim (Hager, 2009; Bernards et al., 2010; Johnson et 

al., 2010). ALS inhibitors, such as the sulfonylureas, imidazolinone, and 

triazolpyrimidine also have been identified for potential control of glyphosate- or 

glufosinate-resistant corn (Hager, 2009; Wisconsin, 2011). Herbicide tank mix additives 

are recommended to increase on-plant spray retention and absorption (see (Hager and 

McGlamery, 1997; Sandell et al., 2009; Johnson et al., 2010). Recommended additives 

44
include crop oil concentrate (COC), methylated seed oil (MSO), and ammonium sulfate 

(Hager and McGlamery, 1997; Johnson et al., 2010; Monsanto, 2010b). Imazethapyr has 

been identified to control up to 80% of the volunteer corn when the corn is still in early 

growth stages (Bernards et al., 2010). The ACCase inhibiting herbicides are to be 

applied prior to the corn reaching the 12 to 24 inch tall stage and the ALS herbicides are 

effective in controlling smaller (2 to 8 inch) corn (Minnesota, 2009; Monsanto, 2010b). 

Volunteer corn in cornfields can be controlled using inter-row cultivation and several 

different herbicides (Minnesota, 2009; Sandell et al., 2009). As noted with volunteer 

corn in soybean, growers can take advantage of alternate modes of herbicide action if the 

herbicide resistance differs between the current crop and the volunteer (e.g., glufosinate 

in LibertyLink® Corn to control a glyphosate-resistant variety(Minnesota, 2009). Preemergent controls might include Gramoxone Inteon (paraquat) mixed with atrazine 

(Sandell et al., 2009; Monsanto, 2010b) . When these two herbicides are used together, 

optimal control is observed if the applications are made before the corn reaches the 6-

inch stage (Monsanto, 2010b). If the volunteer corn is stacked to express both glyphosate

and glufosinate resistance, inter-row cultivation is the only option for post-emergent 

control within corn (Sandell et al., 2009). 

Sorghum has been recommended as an addition to the traditional corn soybean rotation 

cycle (Stalcup, 2010). There are no post-emergent herbicide options to control volunteer 

corn in sorghum; the only control option is inter-row cultivation (Sandell et al., 2009). 

Delayed planting of the sorghum is an option that may be used so as to allow the 

volunteer corn to germinate and then be destroyed with pre-plant tillage (Sandell et al., 

2009). Because of the few options for weed management in sorghum, many growers 

have switched to other crops (Dreiling, 2010). Herbicide-resistant varieties of sorghum 

are being developed, including a variety tolerant to ACCase inhibitors (Dreiling, 2010). 

When such varieties are available, weeds, including volunteer corn, susceptible to the 

ACCase inhibitor herbicides could be controlled in sorghum (Dreiling, 2010). 

Gene Flow to Wild Corn Relatives and to Other Corn Cultivars

The possibility of gene movement from the host plant into native or feral populations of 

Zea species or wild or weedy relatives of corn has been evaluated by the EPA and 

determined as not a concern within the continental U.S. (US-EPA, 2010a). The potential 

for outcrossing or gene escape is defined as the ability of the gene to escape to wild corn 

relatives and APHIS’s Plant Pest Risk Assessment determined that there is no likely route 

for commercial corn gene flow (USDA-APHIS, 2012a). 

Gene flow considerations also include the possibility of pollen transfer between different 

varieties of corn. A variety of plant properties, environmental conditions, and imposed 

conditions can affect movement of genes between com cultivars. For gene flow to occur 

between corn varieties, viable pollen must reach a receptive tassel (Lerner and Dana, 

2001). This then requires that flowering times must overlap, viable pollen transfer 

between the varieties must occur, embryo/seeds must develop, and hybrid seed must 

disperse and establish (see, e.g.(Lerner and Dana, 2001; Diver et al., 2008). Spatial and 

temporal isolation can be one of the most effective barriers to gene exchange between 

com crop cultivars (Mallory-Smith and Zapiola, 2008). Current practices for maintaining 

45
the purity of hybrid seed production in corn are typically successful for maintaining 99% 

genetic purity, though higher instances of out-crossing can occur (Ireland et al., 2006). 

These practices for maintaining varietal purity are also discussed in Subsection 2.1.3 and 

2.1.4 in the context of organic corn and specialty corn systems. 

2.3.3 Microorganisms

Soil microorganisms play a key role in soil structure formation, decomposition of organic 

matter, toxin removal, nutrient cycling, and most biochemical soil processes (Garbeva et 

al., 2004). They also suppress soil-borne plant diseases and promote plant growth (Doran 

et al., 1996). The main factors affecting microbial population size and diversity include 

soil type (texture, structure, organic matter, aggregate stability, pH, and nutrient content), 

plant type (providers of specific carbon and energy sources into the soil), and agricultural 

management practices (crop rotation, tillage, herbicide and fertilizer application, and 

irrigation(Garbeva et al., 2004). Plant roots, including those of corn, release a variety of 

compounds into the soil creating a unique environment for microorganisms in the 

rhizosphere. Microbial diversity in the rhizosphere may be extensive and differs from the 

microbial community in the bulk soil (Garbeva et al., 2004).The structure of soil 

microbial communities is highly dependent on plant type, the physical and chemical 

characteristics of the soil, and climate (Garbeva et al., 2004; Marschner et al., 2004; 

Gupta et al., 2007). As such, potential changes to the soil microbial community as a 

result of cultivating genetically modified crops has been of research interest (O'Callaghan 

and Glare, 2001; Kowalchuk et al., 2003; Dunfield and Germida, 2004). There are 

potential direct and indirect impacts from the large-scale use of GE crops to soil- and 

plant-associated microbial communities, both in the rhizosphere and bulk soil (Lynch et 

al., 2004; Motavalli et al., 2004). Direct impacts could possibly include changes to the 

structural and functional community near the roots due to altered root exudation or the 

transfer of novel proteins into soil, or a change in microbial populations due to the 

changes in agronomic practices used to produce GE crops (e.g., use of agricultural 

chemicals and fertilizers and tillage). Indirect impacts may arise from changes in the 

amount and composition of residue from the GE crops. 

Studies to determine the impact of GE crops on soil microbial communities are mixed. A 

review of those investigating the impact of GE plants on microbial soil communities 

completed by Kowalchuk (2003) found that much of the research examining distinctive 

microbial traits concluded there were minor or no non-target effects; only a few found 

induced targeted alterations to the composition of the microbial community that usually 

resulted in the inhibition of plant pathogenic organisms. A similar review by Motavalli

(2004) did not find any conclusive evidence that released GE plants were causing 

significant direct impacts on microbe-mediated soil nutrient transformations and studies 

of potential indirect impacts were lacking.

Crop rotations influence microorganisms as the chemical and nutrient composition of 

plants and their residues can promote or suppress diseases, affect levels of organic matter, 

and diversify nutrient sources for soil biota (Gupta et al., 2007). Tillage systems can alter 

the physiological and chemical properties and biological composition of soils. No-till 

46
promotes retention of soil organic matter, concentrates soil microorganism activity at the 

soil surface, and increases populations of both disease suppressing and disease promoting 

fungi, in turn increasing species that feed on fungi (Gupta et al., 2007). Conventional 

tillage distributes organisms deeper into the soil, while promoting bacteria and 

bactivorous fauna and increasing residue breakdown accompanied by rapid nutrient 

mineralization (Gupta et al., 2007). Water is one of the important factors influencing 

microbial population structure and activity in soil; thus irrigation can have a substantial 

impact. Soil moisture carries nutrients to microorganisms and supplies hydrogen and 

oxygen (AgriInfo, 2011). Microbes are most active and populous in the moisture range 

of 20% to 60%, while excess moisture conditions can create a low oxygen environment 

beneficial to anaerobic microflora, and too little will not support soil microbial , (Stark 

and Firestone, 1995; AgriInfo, 2011). Fertilizers may support soil microorganisms by

increasing crop growth and residue inputs, building soil organic matter and this providing 

energy and nutrient sources. But fertilizers may change the relative acidity of soils and 

may reduce the beneficial symbiosis of some microorganisms with particular plant 

species (Gupta et al., 2007). Pesticides such as fungicides potentially impact fungal 

microbiota.

In a comparison of fields planted with glyphosate-resistant and conventional corn and 

cotton, Locke (2008) found that glyphosate-resistant crops had subtle and dynamic 

differences in soil microbial populations when compared to non-glyphosate-resistant 

crops. The authors surmise that the decreased disturbance of the soil and increased level 

of residue as a result of reduced tillage on the glyphosate-resistant crops allowed for a 

more diverse microbial population. A 10-year comparison study of GE glyphosateresistant and non-GE corn and soybean by (Kremer and Means, 2009) found that 

glyphosate-resistant soybeans, even when not treated with glyphosate, had a lower 

number and mass of root nodules than that of non-GE soybean, indicating that root 

exudates from GE crops influence the rhizosphere microbial community.

Glyphosate is readily metabolized by soil microbes, yet its strong adsorption capacity to 

soil slows this function (Tu et al., 2001). The average half-life of glyphosate is 47 days, 

yet this rate varies depending on soil structure and microbial population (Senseman, 

2007). The primary metabolite from microbial degradation is AMPA, which is further 

degraded to CO2 (US-EPA, 1993a; Senseman, 2007). Results of research investigating 

the impact of glyphosate on the microbial community are mixed (Weaver et al., 2007). 

For example, Haney (2002) report that glyphosate is mineralized by microorganisms that 

leads to an increase in their population and activity, while Busse (2001) and weaver 

(2007) found little evidence of changes to soil microorganism’s population and activity, 

and any declines recorded were small and not consistent throughout the season. It also 

has been reported that the use of glyphosate increases the colonization of soil-born fungal 

pathogens such as Fusarium (Kremer and Means, 2009; Huber, 2010). Similarly, 

research by (Camberato et al., 2011) found that some weeds treated with glyphosate and 

other herbicides had increased incidence of fungal infection, suggesting that some soil 

fungi are more able to infect a weed after it has been weakened by glyphosate. 

They point out, however, that plant pathologists have not observed widespread increases 

in plant diseases in glyphosate-resistant corn and soybean. In a review of recent studies 

47
investigating a potential link between the use of glyphosate and outbreaks of fungal 

disease, (Powell and Swanton, 2008) did not find sufficient evidence from field trials 

demonstrating whether a causative relationship exists. Additionally, they found that 

observed links may be context dependent, as they were found only under controlled 

laboratory conditions. The authors suggest that to adequately address the effect 

glyphosate has on fungal diseases, future investigations should consider additional 

interactive factors, such as inoculum level, weed abundance and community composition, 

fertility, cultural practices, climate, and soil properties.

2.3.4 Biodiversity

Biodiversity refers to all plants, animals, and microorganisms interacting in an ecosystem 

(Wilson, 1988b; Wilson, 1988a; Wilson et al., 2011b). Biodiversity provides valuable 

genetic resources for crop improvement (Harlan, 1975) and also provides other functions 

beyond food, fiber, fuel, and income. These include pollination, genetic introgression, 

biological control, nutrient recycling, competition against natural enemies, soil structure, 

soil and water conservation, disease suppression, control of local microclimate, control of 

local hydrological processes, and detoxification of noxious chemicals (Altieri, 1999). 

The loss of biodiversity results in a need for costly management practices in order to 

provide these functions to the crop (Altieri, 1999).

The degree of biodiversity in an agroecosystem depends on four primary characteristics: 

1) diversity of vegetation within and around the agroecosystem; 2) permanence of various 

crops within the system; 3) intensity of management; and 4) extent of isolation of the 

agroecosystem from natural vegetation (Southwood and Way, 1970b; Southwood and 

Way, 1970a). Agricultural land subject to intensive farming practices, such as that used 

in crop production, generally has low levels of biodiversity compared with adjacent 

natural areas. Tillage, seed bed preparation, planting of a monoculture crop, pesticide 

use, fertilizer use, and harvest result limit the diversity of plants and animals (Lovett et 

al., 2003).

Field edges can be managed to promote wildlife. These borders are often the least 

productive areas in a farm field and in some cases, the cost of producing crop areas along 

field edges exceeds the value of the crop produced (Sharpe, 2010). Allowing field edges 

to return to volunteer vegetation does contribute to weed seeds in the field, but does not 

contribute to major pest problems in the crop field itself (Sharpe, 2010). Volunteer 

border vegetation, such as ragweed, goldenrod, asters, and forbs, quickly develops into 

nesting and brood habitat for quail and a multitude of songbirds (Sharpe, 2010). 

Maintaining some weeds harbors and supports beneficial arthropods that suppress 

herbivore insect pests (Altieri and Letourneau, 1982; Altieri, 1999). Research conducted 

at North Carolina State University and the North Carolina Wildlife Resources 

Commission found that quail and wintering songbird populations increased when field 

borders along ditch banks were planted by growers (Sharpe, 2010). Adjacent wild 

vegetation provides alternate food and habitat for natural enemies to pest herbivores 

(Altieri and Letourneau, 1982; Altieri, 1999). 

Contour-strip cropping is another management practice that can be used to promote 

wildlife habitat. This practice alternates strips of row crops with strips of solid stand 

48
crops (i.e., grasses, legumes, or small grains) with the strips following the contour of the 

land (Sharpe, 2010). The primary purpose of contour-strip cropping is to reduce soil 

erosion and water runoff, but the solid stand crop also provides nesting and roosting 

cover for wildlife (Sharpe, 2010). Grass-legume refuge strips have also been used to 

increase the population density of predaceous carabid beetles in corn (Zea mays L.) and 

soybean fields (Landis et al., 2005).

Drainage ditches, hedgerows, riparian areas, and adjacent woodlands to a cornfield also 

provide cover, nesting sites, and forage areas, which each contribute to enhancing 

wildlife populations. Ditch banks, for example, function as narrow wetlands that provide 

nesting sites and cover, serve as wildlife corridors, and provide areas for the wildlife to 

occupy when crop fields lack cover (Sharpe, 2010). Ditches have been shown to support 

birds, rodents, reptiles, furbearers, amphibians, fish, and aquatic organisms (Sharpe, 

2010). Minimizing pesticide exposure of ditches, aquatic habitats, border areas, stripcrop areas, and non-crop habitats may help protect fish and wildlife resources (Palmer et 

al., 2011). 

2.4 Public Health

2.4.1 Consumer Health

In the past 30 years, the public’s consumption of corn-based products has more than 

doubled. Per capita consumption of corn products rose from 12.9 pounds annually per 

capita in 1980 to 33 pounds in 2008; and corn sweeteners increased from 35.3 pounds 

annually per capita to 69.2 pounds during that period (USCB, 2011). As of 2012, 88% of 

the corn cultivated is GE (USDA-NASS, 2012a). Public health concerns associated with 

the use of GE corn, such as VCO-01981-5, and GE corn products focus primarily on 

human and animal (livestock) consumption of GE food and feed commodities. This 

subsection provides a summary of the principal human health concerns. Similar issues 

related to livestock use are presented in Subsection 2.5 – Animal Feed. 

There are three principal corn product industries in the U.S.: corn refiners, dry millers, 

and distillers. Corn refiners produce starches, sweeteners, ethanol, feed ingredients, corn 

oil, organic acids, amino acids, and polyols (CRA, 2011). Dry millers manufacture 

flaking grits, snack grits, corn meals, and corn flours (NAMA, 2010) and distillers 

produce beverage and industrial alcohol (CRA, 2006). The production processes in each 

of these industries frequently involve several sequential mechanical and chemical 

processes. Depending on the final product, these processes include washing, heating, 

adjusting pH, steeping in an acid solution, fermentation, mechanical milling and 

centrifugal separation, extrusions, pressing and solvent extraction, evaporation and 

filtration, and final refining (CRA, 2006). Each step in the production process reduces 

residual pesticides in the finished product to non-detectable levels (CRA, 2000). 

Manufacturing operations also have been shown to degrade and denature proteins in corn, 

including those proteins introduced through GE. Thus, dietary exposure to functionally 

active proteins in processed food products can be negligible and below levels of any 

safety concerns (Hammond and Jez, 2011). 

49
Before a pesticide can be used on a food crop, EPA, pursuant to the Federal Food, Drug, 

and Cosmetic Act (FFDCA), must establish a tolerance value establishing the maximum 

pesticide residue that may remain on the crop or in foods processed from that crop. In 

addition, the FDA and the USDA monitor foods for pesticide residues and enforce these 

tolerances (see(USDA-AMS, 2011). Foods derived through biotechnology also undergo 

a comprehensive safety evaluation before entering the market, including reviews under 

the CODEX, the European Food Safety Agency, and the World Health Organization 

(FAO, 2009; Hammond and Jez, 2011). Food safety reviews frequently will compare the 

compositional characteristics of the GE crop with non-GE, conventional varieties of that 

crop (see also(Aumaitre et al., 2002; FAO, 2009). Moreover, this comparison also 

evaluates the composition of the modified crop under actual agronomic conditions, 

including various agronomic inputs (see, e.g.,(Herman et al., 2010). Composition 

characteristics evaluated in these comparative tests include moisture, protein, fat, 

carbohydrates, ash, minerals, dietary fiber, essential and non-essential amino acids, fatty 

acids, vitamins, and antinutrients (Herman et al., 2010). 

Antinutrients represent an important element of this comparison. Antinutrients are 

chemicals produced by a plant which interfere with the absorption and metabolism of the 

consumed vegetable as well as other foods in the digestive tract (Cordain, 1999). 

Antinutrients in corn include lectins, which interfere with vitamin absorption and have 

been associated with cellular level metabolic interference, and trypsin inhibitors, which 

inhibit protein digestion (Cordain, 1999). 

Non-GE corn varieties, both those developed for conventional use and for use in organic 

production systems, are not routinely required to be evaluated by any regulatory agency 

in the U.S. for human food or animal feed safety prior to release in the market. Under the 

FFDCA, it is the responsibility of food and feed manufacturers to ensure that the products 

they market are safe and labeled properly. As a GE product, however, food and feed 

derived from VCO-01981-5 corn must be in compliance with all applicable legal and 

regulatory requirements. GE organisms for food and feed may undergo a voluntary 

consultation process with the FDA prior to release onto the market. Although a voluntary 

process, thus far all applicants who have wished to commercialize a GE variety that 

would be included in the food supply have completed a consultation with the FDA. In 

such consultation, a developer who intends to commercialize a bioengineered food meets 

with the agency to identify and discuss relevant safety, nutritional, or other regulatory 

issues regarding the bioengineered food and then submits to FDA a summary of its 

scientific and regulatory assessment of the food. This process includes: 1) an evaluation 

of the amino acid sequence introduced into the food crop to confirm whether the protein 

is related to known toxins and allergens; 2) an assessment of the protein’s potential for 

digestion; and 3) an evaluation of the history of safe use in food (Hammond and Jez, 

2011). FDA evaluates the submission and responds to the developer by letter with any 

concerns it may have or additional information it may require. Several international 

agencies also review food safety associated with GE-derived food items, including the 

European Food Safety Agency (EFSA) and the Australia and New Zealand Food 

Standards Agency (ANZFS). Genective has provided the FDA with information on the 

identity, function, and characterization of the genes for VCO-1981-5 corn, including 

expression of the gene products. The FDA has completed its early food safety 

evaluation, but has not yet completed its food and nutrition Biotechnology Consultation. 

50
As noted by the National Research Council (NRC), unexpected and unintended 

compositional changes arise with all forms of genetic modification, including both 

conventional hybridization and genetic engineering (NRC, 2004). The NRC also noted in 

its 2004 report that no adverse human health effects attributed to genetic engineering had 

been documented. More recently, the NRC found that the cultivation of GE crops has 

resulted in improvements of pesticide application regimens (applications of fewer 

pesticides or using pesticides with lower environmental toxicity), and that the cultivation 

of herbicide-resistant crops were advantageous because of their superior efficacy in pest 

control and concomitant economic, environmental and presumed personal health 

advantages (NRC, 2010a). Reviews on the nutritional quality of GE foods generally have 

concluded that there are no biologically meaningful nutritional differences in 

conventional versus GE plants for food or animal feed (Aumaitre et al., 2002; Faust, 

2004; Van Deynze et al., 2004). 

Under the FIFRA, all pesticides (which is inclusive of herbicides, insecticides and 

fungicides) sold or distributed in the U.S. must be registered by the EPA (US-EPA, 

2011b). Registration decisions are based on scientific studies that assess the chemical’s 

potential toxicity and environmental impact. To be registered, a pesticide must be able to 

be used without posing unreasonable risks to people or the environment. All pesticides 

registered prior to November 1, 1984, such as glyphosate, must also be reregistered to 

ensure that they meet the current, more stringent standards and have a reregistration 

review every 15 years (US-EPA, 2011b). Glyphosate was first registered in the U.S. in 

1974; the latest reregistration decision for glyphosate was issued in 1993 (US-EPA, 

1993b; US-EPA, 2009f; US-EPA, 2009d). It is currently under reregistration review, 

which began in July 2009 and is scheduled for completion in 2015 (US-EPA, 2009d). 

The EPA’s role in review of corn is more limited. As VCO-01981-5 corn does not 

express any pesticidal properties, the EPA has no FIFRA review authority over this corn 

product. However, if VCO-01981-5 corn provides for a change in use of registered 

herbicides, the EPA would review proposed label changes relating to these new herbicide 

uses. However, Genective does not indicate any change in glyphosate use with the crop 

that would differ from that currently registered for other, similar glyphosate resistant

crops.

The USDA has implemented the Pesticide Data Program (PDP) in order to collect data on 

pesticides residues on food (USDA-AMS, 2011). The EPA uses PDP data to prepare 

pesticide dietary exposure assessments pursuant to the 1996 Food Quality Protection Act. 

Pesticide tolerance levels for glyphosate have been established for a wide variety of 

commodities, including field corn for grain and forage, and are published in the Federal 

Register, 40 CFR §180.364, and the Indexes to Part 180 Tolerance Information for 

Pesticide Chemicals in Food and Feed Commodities (US-EPA, 2011c). Glyphosate 

tolerance for corn grain is 5.0 parts per million (ppm) (40 CFR §180.364). 

Glyphosate is registered under a variety of trade names (e.g., Roundup®, Roundup 

Ultra®, Glyphomax Plus®, and Abundit Extra®) by several companies. There are 

currently over 400 active glyphosate products registered under FIFRA Section 3, and 

over 100 registered for use on terrestrial food crops (US-EPA, 2009c). As mentioned 

above, it was the most widely-used herbicide on corn in 2010, applied to 66% of 

herbicide-treated acres in the U.S. (USDA-NASS, 2011c). In that year, the average 

51
application rate was approximately 1.07 lb/Ac, with a total of over 57.5 million pounds 

applied (USDA-NASS, 2011c). Glyphosate is classified as Toxicity Category III or IV, 

having been found to have low toxicity via the oral, dermal, and inhalation routes (USEPA, 2009d). Similarly, glyphosate is not classified as a carcinogen or teratogen (USEPA, 2009d) While neurotoxicity has not been observed in previous studies, new data 

requirements established under 40 CFR part 158 require acute and subchronic 

neurotoxicity studies, and an immunotoxicity study to take place for reregistration. The 

next RED for glyphosate is scheduled to be complete in 2015 (US-EPA, 2009b). Based 

on toxicological considerations, the EPA Health Effects Division (HED) determined that 

the main metabolite of glyphosate, AMPA, did not need regulation despite levels 

observed in foods or feed (US-EPA, 2009d). Glyphosate when used in accordance with 

the existing labels, have been determined to present no health risk to humans(US-EPA, 

2009d). 

2.4.2 Worker Safety

Worker hazards in farming are common to all types of agricultural production, and 

include hazards of equipment and plant materials. Pesticide application represents the 

primary exposure route to pesticides for farm workers. Pesticides, including herbicides, 

are used on most corn acreage in the U.S. Changes in acreage, crops, or farming practices 

can affect the amounts and types of pesticides used and thus the risks to workers. The 

EPA pesticide registration process, however, involves the design of use restrictions that if 

followed have been determined to be protective of worker health.

EPA’s Worker Protection Standard (WPS) (40 CFR Part 170) was published in 1992 to 

require actions to reduce the risk of pesticide poisonings and injuries among agricultural 

workers and pesticide handlers. The WPS offers protections to more than two and a half 

million agricultural workers who work with pesticides at more than 560,000 workplaces 

on farms, forests, nurseries, and greenhouses. The WPS contains requirements for 

pesticide safety training, notification of pesticide applications, use of personal protective 

equipment, restricted entry intervals following pesticide application, decontamination 

supplies, and emergency medical assistance. 

Worker safety precautions and use restrictions are clearly noted on pesticide registration 

labels. Growers are required to use pesticides consistent with the application instructions 

provided on the EPA-approved pesticide labels. These restrictions provide instructions as 

to the appropriate levels of personal protection required for agricultural workers to use 

herbicides. These may include instructions on personal protective equipment, specific 

handling requirements, and field reentry procedures (Monsanto, 2007; Nufarm, 2009; 

DuPont, 2010). These label restrictions carry the weight of law and are enforced by the 

EPA and the states (FIFRA 7 U.S.C. 136j (a)(2)(G) Unlawful Acts); therefore, it is 

expected that glyphosate use on Maize Line HCEM485 would be consistent with the 

EPA-approved labels. Used in accordance with the label, these herbicides have been 

determined to not present a health risk to workers (US-EPA, 1993b). The worker safety 

implications of the proposed changes in application rates and use of these two herbicides 

are discussed in Subsection 4.5. 

52
2.5 Animal Feed

Corn comprises approximately 95% of the total feed grain production and use, with 

sorghum, barley, and oats making up the remainder (USDA-ERS, 2011b). The 

production of corn for feed use is a derived demand, i.e., production of corn for feed will 

vary depending on the number of animals (cattle, hogs, and poultry) being fed corn 

(USDA-ERS, 2011b). The amount of corn used for feed also depends on the crop’s 

supply and price (USDA-ERS, 2011b). 

Corn is valuable as a feed because of its composition, including key nutrients, antinutrients and secondary metabolites, protein content, fiber, among others (OECD, 

2002b). Corn grain is used for feed for beef cattle, poultry, hogs and dairy cattle, with 

beef cattle consuming the largest volume harvested , (NCGA, 2009). Animal feed derived 

from corn comes not only from the unprocessed grain, but also from silage, the aboveground portions of the corn plant, and stalk residues in fields that might be grazed and 

from the residuals derived from three major corn industries: corn refining, corn dry 

millers, and distillers (OECD, 2002b; CRA, 2006). Animal feed products from corn 

refining and wet milling include corn gluten feed, corn gluten meal, corn germ meal, corn 

steep liquor, and amino acids (CRA, 2006). 

Corn gluten feed is the residue remaining after the extraction of starch, gluten, and germ 

(CRA, 2006). Corn gluten feed is considered a medium protein product and is used 

widely in complete animal feeds for dairy and beef cattle, poultry, and hogs (CRA, 2006). 

Corn gluten meal is a high-protein ingredient consisting of corn proteins separated in the 

milling process, and may contain as much as 60% protein (CRA, 2006). Corn gluten 

meal has a high xanthophyll content, a yellow plant pigment, making this product highly 

valued as a pigmenting ingredient in poultry feeds (CRA, 2006). The high protein 

content also is valued as a cattle feed to protect the cow’s rumen (CRA, 2006). Corn 

germ meal is a residual product obtained from the corn germ after the corn oil has been 

extracted (CRA, 2006). Corn germ meal is a small fraction of the corn kernel, and has a 

small market in animal feed as a carrier for liquid nutrients (CRA, 2006). Corn steep 

liquor is a high protein product comprised of the soluble portions of the corn kernel 

removed during the corn steep process (CRA, 2006). Corn steep liquor is sometimes 

combined with other ingredients in corn gluten feed or provided as a liquid protein source 

(CRA, 2006). Amino acids are produced through the fermentation of corn-derived 

dextrose (CRA, 2006). Lysine, an essential animal amino acid, is a highly valued cornderived amino acid for both poultry and swine (CRA, 2006). Threonine and tryptophan 

amino acid feed supplements also are produced from corn (CRA, 2006). 

As described in Subsection 2.4, Human Health, under FIFRA, all pesticides (including 

herbicides) sold or distributed in the U.S. must be registered by the EPA (US-EPA, 

2011b). All pesticides registered prior to November 1, 1984, such as glyphosate, must 

also be reregistered to ensure that they meet the current, more stringent standards and 

should have a reregistration review every 15 years (US-EPA, 2011b). The latest 

reregistration decision for glyphosate was issued in 1993 and the reregistration review 

was started in July 2009 (US-EPA, 2009f; US-EPA, 2009d). Before a pesticide can be 

used on a food or feed crop, the EPA must establish the tolerance value, which is the 

maximum amount of pesticide residue that can remain on the crop or in foods or feed 

53
processed from that crop (US-EPA, 2011e). Glyphosate currently has established 

tolerances for residues, including established residue concentrations for glyphosate in 

field corn for forage, grain, and stover , (US-EPA, 2011c). Pesticide tolerance levels for 

glyphosate have been established for corn and are published in the Federal Register, 

CFR, and the Indexes to Part 180 Tolerance Information for Pesticide Chemicals in Food 

and Feed Commodities (US-EPA, 2011c). The glyphosate tolerance level established for 

field corn intended for forage is 6.0 ppm and for grain corn is 5.0 ppm (40 CFR 

§180.364). 

2.6 Socioeconomic

Corn is produced for food and feed commodities as well as industrial uses (USDA-ERS, 

2011b). Corn is the most widely cultivated feed grain in the U.S., accounting for more 

than 95% of total value and production of feed grains (James, 2009; USDA-ERS, 2011b). 

Corn is grown in all 48 of the continental U.S. states with production concentrated in the 

Corn Belt, loosely defined as the states of Illinois, Iowa, Indiana, the eastern portions of 

South Dakota and Nebraska, western Kentucky and Ohio, and the northern two-thirds of 

Missouri (USDA-NASS, 2010b; USDA-ERS, 2011b; USDA-NASS, 2012a). Iowa and 

Illinois are the two top corn producing states and typically account for more than onethird of the total U.S. crop (USDA-ERS, 2011b). 

2.6.1 Domestic Economic Environment

In the 2012 production year, corn was cultivated on over 96 million acres, a 5% increase 

in corn acreage from 2011 (37.4 million hectares) (USDA-NASS, 2012a). In 2011, corn 

for silage was cultivated on approximately 5.9 million acres, or approximately 6% of the 

total corn production area for that year , (USDA-NASS, 2012b). GE herbicide-resistant

corn comprised approximately 21% of the total corn acreage in the U.S., insect-resistant 

varieties comprised 15% of the acreage, and stacked varieties comprising 52% of the 

total corn acreage (USDA-NASS, 2012a)). The costs for GE corn seed are higher than 

that for conventional seed. Growers pay a premium for GE seed, with growers in 2008 

paying as much as 50% more for GE corn seed than conventional seed (NRC, 2010a). 

This seed premium includes a technology fee for the cultivation of the seed (NRC, 

2010a). 

Corn production in 2011 was estimated at 12.44 billion bushels, valued at an estimated 

$5.15 to $5.65 per bushel (i.e., a total value of $64.1 – 70.3 billion). In 2012, production 

was estimated at 12.38 billion bushels (USDA-NASS, 2012b). The value of the corn 

crop varies over time in response to market conditions. Because of severe drought 

throughout the Corn Belt, the estimates for corn production in 2012 were projected 

sharply lower. In August, 2012, the season average farm price for corn was projected at 

$7.50 to $8.90 per bushel, a 39% increase in price from the previous month and a 58% 

average increase over 2011 (USDA-OCE, 2012). U.S. prices for corn, although declining 

somewhat over the course of the year, are expected to remain high because of the 

continued demand for corn for ethanol, animal feed, and exports (James, 2009; USDANASS, 2012a; USDA-OCE, 2012).

Corn processed for human consumption and industrial uses accounts for about one-third 

of domestic corn utilization (USDA-ERS, 2011b). During processing, corn is either wet 

54
or dry milled depending on the desired end products: wet millers process corn into highfructose 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 (USDA-ERS, 2011b).

The cultivation of corn for animal feed varies depending upon the demand in the 

livestock industry (USDA-ERS, 2011b). Direct feeding of corn to livestock has declined 

in response to declines in meat production since 2007 in the U.S., as well as utilization of 

certain corn by-products for livestock feeds (USDA-OCE, 2011a). The production of 

ethanol generates several economically valuable co-products, including distillers dried 

grains with solubles (DDGs) (USDA-ERS, 2011b). Each 56 pound bushel of corn used 

in dry mill ethanol production generates approximately 17.4 pounds of DDGs which are 

fed to livestock (USDA-ERS, 2011b). Food and industrial use of corn (other than for 

ethanol production) is projected to increase, although this demand also is related to 

specific products (USDA-OCE, 2011a). Demand for HFCS, glucose and dextrose is 

expected to increase, but at lower rates than previous years. Corn starch is considered an 

industrial product, the production of which is contingent on industrial demand (USDAOCE, 2011a). 

Corn production has increased over time, as higher yields followed improvements in 

technology (seed varieties, pesticides, and machinery) and in production practices 

(reduced tillage, irrigation, crop rotations, and pest management systems) (USDA-ERS, 

2011b). Corn acreage in the U.S. increased during the second half of the 2000s. The 

establishment of a bioethanol industry using corn as a feed stock has been identified as 

one of the key elements in the increase in acreage devoted to corn, with approximately 

40% of the corn harvest now dedicated to corn-based biofuel production (Swoboda, 

2009; USDA-NASS, 2011b; Wilson, 2011; USDA-NASS, 2012a; USDA-OCE, 2012). 

Corn acreage is expected to increase, with as farmers convert other crops, especially 

soybean, to corn cultivation to support both ethanol production and export demand 

(USDA-ERS, 2011b). Over the past 20 years, the acreage per corn farm has increased, 

and the number of large corn farms (more than 500 acres) has increased, while the 

number of small corn farms (less than 500 acres) has declined (USDA-ERS, 2011b).

The adoption of GE corn in U.S. has reduced costs and improved profitability levels on 

the farm (Carpenter et al., 2002; Brookes and Barfoot, 2010). These cost reductions are a 

result of reductions in average herbicide and pesticide use per field, and corresponding 

reductions in tillage and associated field cultivation costs (Carpenter et al., 2002; Brookes 

and Barfoot, 2010). Other benefits to the grower from adoption of GE crops have 

included (Carpenter et al., 2002; Brookes and Barfoot, 2010):

55
• Increased management flexibility and convenience arising from the ease of use of 

broad-spectrum herbicides like glyphosate;

• A decrease in “knock-back” of the crop associated with post-emergent 

applications of herbicides on the herbicide-resistant crop;

• Reduced harvesting costs;

• Higher quality harvested crop;

• An improvement in soil quality as growers reduce quantities of soil-applied 

herbicides and increase limited tillage; and

• Overall improvements in human health costs associated with use of less toxic 

products.

Herbicide-resistant corn has been cultivated commercially since 1997. Adoption of a GE 

herbicide-resistant weed control system has reduced grower costs and increased 

profitability, with average profitability improved by $20/hectare to $25/hectare in most 

years when compared with the costs of conventional herbicide treatment used to gain the 

same level of control in a low/reduced till system (Brookes and Barfoot, 2010). 

Recently, these net cost savings have decreased as a consequence of an increase in the 

price of glyphosate and other weed control programs (Brookes and Barfoot, 2010). 

Continued demands for corn for ethanol have resulted in some shifts in the corn/soybean 

rotation in some areas (Hart, 2006). Corn and soybeans frequently were cultivated in two 

year rotation, but as the demand for corn for ethanol increased, many growers in the 

upper Midwest converted to a three year rotation schedule, with two consecutive years of 

corn followed by a year of soybean (Hart, 2006). Although there are certain economic 

benefits from this change, there also are some costs. Tillage costs may increase in the 

second year of corn, for example, if the crop residues from the first corn year prevent notill planting in the second year (Babcock and Hennessy, 2006). Corn after corn rotations 

also can impact pest and weed problems as certain corn-specific pests and weeds 

overwinter in the corn residues remaining in the field (Babcock and Hennessy, 2006). 

These impacts can be managed through greater crop monitoring, increased applications of 

pesticides and selection of appropriate hybrids (Babcock and Hennessy, 2006 233). 

An important concern currently facing U.S. farmers, including corn farmers, is the 

emergence of glyphosate-resistant weeds (Johnson and Gibson, 2006; Foresman and 

Glasgow, 2008; Hurley et al., 2009; Johnson et al., 2009), a result of the repeated, wide 

spread, and sometimes exclusive use of glyphosate on corn, cotton, and soybean crops 

resistant to the pesticide (Beckie, 2006b; Duke and Powles, 2009). As of 2012, there 

were 13 different weed species with glyphosate-resistant populations ranging across 

25different U.S. states (Heap, 2012) (see Subsection 2.3.2, Plants Communities, Table 

2.10 and 2.11). Comparing the typical glyphosate-resistant weed management programs 

to a typical nonherbicide-resistant weed management program, Sankula and Blumenthal 

(2004; Sankula, 2006) estimated that farmers saved $9.49 to $10.15 per acre in weed 

management costs. Based on 2007 survey data, Hurley, Mitchell, and Frisvold (2009), 

found that farmers planting more glyphosate-resistant corn reported lower weed 

management costs.

Surveys indicate that farmers prefer to address glyphosate-resistant weeds by using 

additional herbicides with different modes of action (Johnson and Gibson, 2006; 

56
Foresman and Glasgow, 2008; Johnson et al., 2009). Weirich et al. (2011b) investigated 

the effect of grower adoption of alternative glyphosate weed resistance management 

programs, finding they increased cost substantially, though they did not statistically 

significantly decrease net returns due to higher yields. These results suggest that growers 

may be able to effectively respond to glyphosate resistance using weed BMPs without 

substantially affecting their returns.

2.6.2 Trade Economic Environment

Corn is the dominant feed grain traded internationally (James, 2009; USDA-OCE, 2011a; 

USDA-OCE, 2012). In 2011/2012, the U.S. produced approximately 37% of the total 

world supply of corn (USDA-OCE, 2011a; USDA-OCE, 2012). Corn is cultivated 

worldwide, including in the European Union, Argentina, South Africa, Brazil, Canada, 

China, and the former Soviet Union States, including the Ukraine(USDA-OCE, 2011a; 

USDA-OCE, 2012). GE Corn is cultivated on 27% of all corn acreage worldwide 

(James, 2009). 

As the global demand for meat increases along with the commercialization of livestock 

feeding, international trade in livestock feed and protein meal supplements also increases, 

particularly in those countries where climate and geography restrict local production of 

these feed materials (USDA-FAS, 2012; USDA-OCE, 2012). Approximately 15 to 20% 

of the U.S. corn production is exported, with the volume of exports projected to to 

decrease in the next several years in the face of increased competition from lower-priced 

South American supplies (DAS, 2010; USDA-OCE, 2011a; USDA-OCE, 2012). Egypt, 

the EU, Japan, Mexico, Southeast Asia, and South Korea are net importers of corn 

(Brookes and Barfoot, 2010; USDA-OCE, 2011a; USDA-OCE, 2012). China is 

projected to become a net importer of corn to support its expanding livestock and 

industrial sectors (James, 2009; USDA-OCE, 2011a; USDA-OCE, 2012). The increase 

in China’s imports is expected to account for one-third of the growth in world corn 

trade(USDA-OCE, 2011a; USDA-OCE, 2012). In addition to corn as grain, corn gluten 

feed is a major product in international trade in feed ingredients. Large volumes of U.S. 

corn gluten feed are exported to the EU (CRA, 2006).

Identity protection is important in international trade. Specific end uses also may require 

identity protection throughout the export supply chain. Value enhanced, specialty corn is 

an important part of the U.S. export market for corn. High oil corn, for example, is in 

high export demand as a replacement for animal fats in feed rations (USDA-FAS, 2004). 

As discussed in Subsection 2.1.4, Specialty Corn Production, the challenges associated 

with maintaining variety identity in international commodity movement increases the 

costs, as well as the premiums paid, for these specialty crops (USDA-FAS, 2004). 

GE corn, such as VCO-01981-5 are excluded by some countries sensitive to the 

importation of GE crops. Other countries may lag approval of new US GE corn varieties

and these may cause disruptions in international trade when they are inadvertently 

incorporated into feed grain shipments or specialty corn fractions such as corn gluten

(See, e.g., ICTSD(ICTSD, 2005)

57
3 ALTERNATIVES

This document analyzes the potential environmental consequences of a determination of 

nonregulated status of Genective VCO-01981-5. To respond favorably to a petition for 

nonregulated status, APHIS must determine that event VCO-01981-5 is unlikely to pose 

a plant pest risk. Based on its PPRA (USDA-APHIS, 2012a), APHIS has concluded that 

event VCO-01981-5 is unlikely to pose a plant pest risk. Therefore, APHIS must 

determine that event VCO-01981-5 is no longer subject to 7 CFR part 340 or the plant 

pest provisions of the Plant Protection Act. 

Two alternatives are evaluated in this EA: (1) no action and (2) determination of 

nonregulated status of event VCO-01981-5. APHIS has assessed the potential for 

environmental impacts for each alternative in the Environmental Consequences section.

3.1 No Action Alternative: Continuation as a Regulated Article

Under the No Action Alternative, APHIS would deny the petition. Event VCO-01981-5 

corn and progeny derived from VCO-01981-5 corn would continue to be regulated 

articles under the regulations at 7 CFR part 340. Permits issued or notifications 

acknowledged by APHIS would still be required for introductions of VCO-01981-5 corn 

and measures to ensure physical and reproductive confinement would continue to be 

implemented. APHIS might choose this alternative if there were insufficient evidence to 

demonstrate the lack of plant pest risk from the unconfined cultivation of VCO-01981-5 

corn. 

This alternative is not the Preferred Alternative because APHIS has concluded through a 

Plant Pest Risk Assessment that VCO-01981-5 corn is unlikely to pose a plant pest risk

(USDA-APHIS, 2012a). Choosing this alternative would not satisfy the purpose and 

need of making a determination of plant pest risk status and responding to the petition for 

nonregulated status. 

3.2 Preferred Alternative: Determination that VCO-01981-5 Corn is No Longer a 

Regulated Article

Under this alternative, VCO-01981-5 corn and progeny derived from them would no 

longer be regulated articles under the regulations at 7 CFR part 340. VCO-01981-5 is 

unlikely to pose a plant pest risk (USDA-APHIS, 2012a). Permits issued or notifications 

acknowledged by APHIS would no longer be required for introductions of VCO-01981-5 

corn and progeny derived from this event. This alternative best meets the purpose and 

need to respond appropriately to a petition for nonregulated status based on the 

requirements in 7 CFR part 340 and the agency’s authority under the plant pest 

provisions of the Plant Protection Act. Because the agency has concluded that event 

VCO-01981-5 is unlikely to pose a plant pest risk, a determination of nonregulated status 

of VCO-01981-5 corn is a response that is consistent with the plant pest provisions of the 

PPA, the regulations codified in 7 CFR part 340, and the biotechnology regulatory 

policies in the Coordinated Framework.

58
Under this alternative, growers may have future access to VCO-01981-5 corn and 

progeny derived from this event if the developer decides to commercialize VCO-01981-5 

corn. 

3.3 Alternatives Considered But Rejected from Further Consideration

APHIS assembled a list of alternatives that might be considered for VCO-01981-5. The 

agency evaluated these alternatives, in light of the agency's authority under the plant pest 

provisions of the Plant Protection Act, and the regulations at 7 CFR part 340, with respect 

to environmental safety, efficacy, and practicality to identify which alternatives would be 

further considered for VCO-01981-5 corn. Based on this evaluation, APHIS rejected 

several alternatives. These alternatives are discussed briefly below along with the 

specific reasons for rejecting each.

3.3.1 Prohibit Any VCO-01981-5 Corn from Being Released

In response to public comments that stated a preference that no GE organisms enter the

marketplace, APHIS considered prohibiting the release of VCO-01981-5 corn, including 

denying any permits associated with the field testing. APHIS determined that this 

alternative is not appropriate given that APHIS has concluded that VCO-01981-5 is 

unlikely to pose a plant pest risk (USDA-APHIS, 2012a).

In enacting the Plant Protection Act, Congress found that 

[D]ecisions affecting imports, exports, and interstate movement of products 

regulated under [the Plant Protection Act] shall be based on sound science...§ 

402(4).

On March 11, 2011, in a Memorandum for the Heads of Executive Departments and 

Agencies, the White House Emerging Technologies Interagency Policy Coordination 

Committee developed broad principles, consistent with Executive Order 13563, to guide 

the development and implementation of policies for oversight of emerging technologies 

(such as genetic engineering) at the agency level. In accordance with this memorandum, 

agencies should adhere to Executive Order 13563 and, consistent with that Executive 

Order, the following principle, among others, to the extent permitted by law, when 

regulating emerging technologies: 

“[D]ecisions should be based on the best reasonably obtainable scientific, 

technical, economic, and other information, within the boundaries of the 

authorities and mandates of each agency” 

Based on the Plant Pest Risk Assessment (USDA-APHIS, 2012a) and the scientific data 

evaluated therein, APHIS concluded that VCO-01981-5 is unlikely to pose a plant pest 

risk. Accordingly, there is no basis in science for prohibiting the release of VCO-01981-

5 corn.

59
3.3.2 Approve the Petition in Part

The regulations at 7 CFR 340.6(d)(3)(i) state that APHIS may "approve the petition in 

whole or in part." For example, a determination of nonregulated status in part may be 

appropriate if there is a plant pest risk associated with some, but not all lines described in 

a petition. Because APHIS has concluded that VCO-01981-5 is unlikely to pose a plant 

pest risk, and it is the only line in the petition, there is no regulatory basis under the plant 

pest provisions of the Plant Protection Act for considering approval of the petition only in 

part. 

3.3.3 Isolation Distance between VCO-01981-5 and Non-GE Corn Production 

and Geographical Restrictions

In response to public concerns of gene movement between GE and non-GE plants, 

APHIS considered requiring an isolation distance separating VCO-01981-5 from 

conventional or specialty corn production. However, because APHIS has concluded that 

VCO-01981-5 is unlikely to pose a plant pest risk (USDA-APHIS, 2012a), an alternative 

based on requiring isolation distances would be inconsistent with the statutory authority 

under the plant pest provisions of the Plant Protection Act and regulations in 7 CFR part 

340. 

APHIS also considered geographically restricting the production of VCO-01981-5 corn

based on the location of production of non-GE corn in organic production systems or 

production systems for GE-sensitive markets in response to public concerns regarding 

possible gene movement between GE and non-GE plants. However, as presented in 

APHIS’ plant pest risk assessment for VCO-01981-5, there are no geographic differences 

associated with any identifiable plant pest risks for VCO-01981-5 (USDA-APHIS, 

2012a). This alternative was rejected and not analyzed in detail because APHIS has 

concluded that VCO-01981-5 does not pose a plant pest risk, and will not exhibit a 

greater plant pest risk in any geographically restricted area. Therefore, such an 

alternative would not be consistent with APHIS’ statutory authority under the plant pest 

provisions of the Plant Protection Act and regulations in Part 340 and the biotechnology 

regulatory policies embodied in the Coordinated Framework.

Based on the foregoing, the imposition of isolation distances or geographic restrictions 

would not meet APHIS’ purpose and need to respond appropriately to a petition for 

nonregulated status based on the requirements in 7 CFR part 340 and the agency’s 

authority under the plant pest provisions of the Plant Protection Act. However, 

individuals might choose on their own to geographically isolate their non-GE corn

production systems from VCO-01981-5 corn or to use isolation distances and other 

management practices to minimize gene movement between VCO-01981-5 and non-GE 

fields. Information to assist growers in making informed management decisions for 

VCO-01981-5 is available from Association of Official Seed Certifying Agencies 

(AOSCA, 2010).

60
3.3.4 Requirement of Testing for Presence of VCO-01981-5 

During the comment periods for other petitions for nonregulated status, some 

commenters requested USDA to require and provide testing for GE products in non-GE 

production systems. APHIS notes there are no nationally-established regulations 

involving testing, criteria, or limits of GE material in non-GE systems. Such a 

requirement would be extremely difficult to implement and maintain. Additionally, 

because VCO-01981-5 does not pose a plant pest risk (USDA-APHIS, 2012a), the 

imposition of any type of testing requirements is inconsistent with the plant pest 

provisions of the Plant Protection Act, the regulations at 7 CFR part 340 and 

biotechnology regulatory policies embodied in the Coordinated Framework. Therefore, 

imposing such a requirement for VCO-01981-5 would not meet APHIS’ purpose and 

need to respond appropriately to the petition in accordance with its regulatory authorities. 

3.4 Comparison of Alternatives 

Table 4 presents a summary of the potential impacts associated with selection of either of 

the alternatives evaluated in this EA. The impact assessment is presented in Section 4 of 

this EA. 

Table 3-1: Summary of issues of potential impacts and consequences of alternatives.

Attribute/Measure Alternative A: No Action Alternative B: Determination of 

Nonregulated Status

Meets Purpose and 

Need and 

Objectives

No Yes

Unlikely to pose a 

plant pest risk

Satisfied through use of 

regulated field trials

Satisfied—risk assessment (USDAAPHIS, 2012b)

Management 

Practices

Acreage and Areas 

of Corn Production

Yearly fluctuation but no or 

small net increase of acreage 

and no new regions of corn 

planted

Unchanged from No Action 

Alternative

Agronomic 

Practices

Cropping practices will remain 

the same as current practices 

for commercial corn production

Unchanged from No Action 

Alternative

Pesticide Use Herbicide use patterns unlikely 

to change

Herbicide use of some types may 

decrease

61
Corn Seed 

Production

Fluctuates yearly somewhat; 

foreign seed production is used 

to respond to specific needs 

Unchanged

Organic Corn 

Production

Yearly production not affected 

by conventional corn 

production

Unchanged

Environment

Land Use Corn acreage generally stable 

but fluctuates yearly

VCO-01981-5 corn is not expected 

to have any effect on land use 

Water Resources Herbicides in water fluctuate 

with weather, climate and 

usage 

VCO-01981-5 corn is not expected 

to have any effect on water 

Soil Glyphosate in soil has a short 

half-life. Conservation tillage 

may be increasing slightly 

VCO-01981-5 corn is not expected 

to have any effect on soil 

Air Quality Air quality (particulates) 

affected by tillage and weather

VCO-01981-5 corn is not expected 

to have any effect on air quality 

Climate Change Climate changes affected by 

land use, tillage and greenhouse 

gases

VCO-01981-5 corn is not expected 

to have any effect on climate change 

Animals and Plants

Animals Vertebrates interact 

infrequently with corn 

agriculture; invertebrates not 

likely to have new impacts from 

corn production compared to 

any other agricultural 

production

VCO-01981-5 corn and glyphosate is 

not expected to have any effect on 

vertebrate animals or most 

invertebrate animals. Unchanged 

from the No Action Alternative

Plants Natural vegetation highly 

reduced near farms; herbicide 

resistant weeds increasing

VCO-01981-5 corn is not expected 

to have any new effect on plants or 

resistance

Gene Movement No gene flow to wild plants; 

gene flow to other corn easily 

controlled. Horizontal gene 

flow not observed

VCO-01981-5 corn is not expected 

to have any effect on vertical or 

horizontal gene flow 

62
Soil Microorganisms Microorganisms affected by 

tillage, agronomic activity and 

pesticides 

VCO-01981-5 corn is not expected 

to have any novel effect on soil 

microorganisms 

Biological Diversity Contemporary agriculture 

impacts diversity but new 

impacts not likely to be 

significant 

VCO-01981-5 corn is not expected 

to have any effect on biological 

diversity 

Human and Animal 

Health

Risk to Human 

Health

EPA rates glyphosate impacts 

from glyphosate resistant corn 

as having no reasonable 

certainty of harm 

VCO-01981-5 corn does not have 

any adverse human health effects. 

Unchanged from No Action

Risk to Animal Feed Corn is a major feed protein for 

animal nutrition; quality is 

unchanging and adequate to 

animal needs

VCO-01981-5 supplies no changes in 

animal nutrition compared to other 

corn

Socioeconomic

Domestic and 

Economic 

Environment

Corn seed with various traits 

has a competitive market in the 

US, with four major seed 

suppliers, and over a hundred 

smaller ones

VCO-01981-5 would be just anotyer 

glyphosate resistant corn, 

potentially replacing others in the 

domestic corn seed market

Trade Economic 

Environment

Corn export levels decreased by 

23% from 2010 to 2012 in the 

US

VCO-01981-5 corn production would 

have no substantial differences from 

existing corn

Other Regulatory 

Approvals

Completed FDA early food 

safety consultation; final 

consultation in progress. EPA 

tolerance exemptions and 

conditional pesticide 

registrations granted

Completed FDA early food safety 

consultation, final consultation in 

progress. EPA tolerance exemptions 

and conditional pesticide 

registrations granted

Compliance with 

Other Laws

CWA, CAA, Eos Fully compliant Fully compliant

63
4 ENVIRONMENTAL CONSEQUENCES

This analysis of potential environmental consequences addresses the potential impact to 

the human environment from the alternatives analyzed in this EA, namely taking no 

action and a determination by the agency that VCO-01981-5 does not pose a plant pest 

risk. Potential environmental impacts from the No Action Alternative and the Preferred 

Alternative for VCO-01981-5 are described in detail throughout this section. A 

cumulative effects analysis is presented for each potentially affected environmental 

concern. Certain aspects of this product and its cultivation would be no different between 

the alternatives: those instances are described below.

4.1 Scope of Analysis

Potential environmental impacts from the No Action Alternative and the Preferred 

Alternative for VCO-01981-5 corn are described in detail throughout this section. An 

impact would be any change, positive or negative, from the existing (baseline) conditions 

of the affected environment (described for each resource area in Section 2.0). Impacts 

may be categorized as direct, indirect, or cumulative. A direct impact is an effect that 

results solely from a proposed action without intermediate steps or processes. Examples 

include soil disturbance, air emissions, and water use. An indirect impact may be an 

effect that is related to but removed from a proposed action by an intermediate step or 

process. Examples include surface water quality changes resulting from soil erosion due 

to increased tillage, and worker safety impacts resulting from an increase in herbicide 

use. 

A cumulative effects analysis is also included for each environmental issue. A cumulative 

impact may be an effect on the environment which results from the incremental impact of 

the proposed action when added to other past, present, and reasonably foreseeable future 

actions. Examples include breeding VCO-01981-5 with other deregulated events. If 

there are no direct or indirect impacts identified for a resource area, then there can be no 

cumulative impacts. Cumulative impacts are discussed in Section 5.

Where it is not possible to quantify impacts, APHIS provides a qualitative assessment of 

potential impacts. Certain aspects of this product and its cultivation may be no different 

between the alternatives; those are described below. 

Although the preferred alternative would allow for new plantings of VCO-01981-5 to 

occur anywhere in the U.S., APHIS will limit the environmental analysis to those areas 

that currently support corn production. To determine areas of corn production, APHIS 

used data from various official USDA sources. 

4.2 Agricultural Production of Corn

Best management practices are commonly accepted, practical ways to grow corn, 

regardless of whether the corn farmer is using organic practices or conventional practices 

with non-GE or GE varieties. These management practices consider crop-specific 

planting dates, seeding rates, and harvest times, among others. Over the years, corn

production has resulted in well-established management practices that are available 

64
through local Cooperative Extension Service offices and their respective websites. The 

National Information System for the Regional Integrated Pest Management (IPM) 

Centers publishes crop profiles for major crops on a state-by-state basis. These crop 

profiles provide production guidance for local growers, including recommended practices 

for specific pest control. Crop profiles for many of the soybean production states can be 

reviewed (IPM-Centers, 2013).

Genective’s studies demonstrate that agronomic characteristics and cultivation practices 

required for VCO-01981-5 corn are essentially indistinguishable from practices used to 

grow other corn varieties, including other herbicide-resistant varieties (Genective, 2012; 

USDA-APHIS, 2012a). None of the BMPs currently employed for corn production is 

expected to change if VCO-01981-5 corn is no longer subject to the regulatory 

requirements of 7 CFR Part 340 or the plant pest provisions of the Plant Protection Act of 

2000. Accordingly, the potential impacts on agricultural production of VCO-01981-5 

corn resulting from management practices associated with the No Action and Preferred 

Alternative are the same.

4.2.1 Acreage and Area of Corn Production

No Action Alternative: Acreage and Area of Corn Production

Based on current acreage trends, conventional corn production practice along with GE 

varieties will likely continue to increase in acreage under the No Action Alternative. As 

discussed in Subsection 2.1 – Agricultural Production of Corn, this trend towards 

increase in corn cultivation is not a result of cultivation of new farm land or conversion of 

conservation reserves to corn, but is instead a consequence of the grower’s substitution of 

corn for other crops to take advantage of current crop pricing(Wallander et al., 2011). 

Corn currently is produced commercially in 48 states (USDA-NASS, 2012b; USDANASS, 2012a) and under the No Action Alternative, the number of states involved in 

corn cultivation is not expected to change. 

Since 2006, U.S. corn planted acreage has increased as market prices have favored the 

planting of corn over alternative crops, such as cotton (USDA-NASS, 2011b; USDANASS, 2012a). The increase in corn acreage has been linked to the increase in demand 

for corn as a feed stock for ethanol for biofuel (Hart, 2006; USDA-ERS, 2010c). The 

increase in acreage has involved all varieties of corn and is occurring throughout the corn 

growing areas (USDA-ERS, 2010c). The USDA has estimated that over 90 million acres 

of corn will be required to meet the demands of ethanol, livestock, and export (Hart, 

2006). The increased acreage to fulfill the added requirements for ethanol production is 

expected to come from the upper Midwest and eastern Great Plains areas (Hart, 2006). 

Preferred Alternative: Acreage and Area of Corn Production

Genective’s studies and USDA-APHIS analyses demonstrate that agronomic 

characteristics and cultivation practices required for VCO-01981-5 corn are essentially 

indistinguishable from other corn varieties, including other herbicide-resistant varieties 

65
(Genective, 2012; USDA-APHIS, 2012a). There are no changes in agronomic 

characteristics in VCO-01981-5 corn that would result in an increase in acreage devoted 

to corn or a change in the range where corn is already cultivated in the U.S. (USDAAPHIS, 2012a). As noted in the No Action analysis in Subsection 4.2.1.1, the trend in 

increase in corn acreage is a function of market conditions driving growers to substitute 

corn for other crops. This trend is not specific to a single GE corn variety (Wallander et 

al., 2011). VCO-01851-5 corn provides growers with the ability to use the broad 

spectrum herbicide glyphosate with other corn herbicides for weed control, since 

glyphosate is a suitable tank mix partner for nearly fifty other herbicides (Monsanto, 

2010a; Genective, 2012). 

Results of the agronomic and morphologic assessments conducted by Genective indicate 

that the introduced herbicide resistance trait does not confer any competitive advantage in 

terms of weediness (USDA-APHIS, 2012a). Genective asserts that VCO-01981-5 corn 

will be a replacement product for other varieties of corn currently cultivated, so new 

acreage is not expected to accommodate the cultivation of VCO-01981-5 corn 

(Genective, 2012). The glyphosate resistance trait, already in commercial use for fifteen 

years, is not expected to extend the range of cultivation for VCO-01981-5 corn outside of 

existing cultivation areas (Genective, 2012). 

The Preferred Alternative, i.e., a determination of nonregulated status of VCO-01981-5 

corn, is therefore not expected to increase corn production, either by its availability alone 

or associated with other factors, or result in an increase in overall acreage of GE corn. 

Potential impacts would be similar to the No Action Alternative. 

4.2.2 Agronomic Practices

As discussed in Subsection 2.1.2 – Agronomic Practices, corn cultivation requires 

significant management considerations regarding tillage, rotation strategy, agricultural 

inputs, and pesticide inputs. Decisions concerning corn agronomic practice are 

dependent on grower want and need, and ultimately reflective of geography, weed and 

disease pressure, economics of management strategies, and production system (rotation) 

flexibility (Heiniger, 2000; Farnham, 2001; University-of-Arkansas, 2008). For example, 

corn intended for grain is likely to require less tillage and less frequent herbicide or 

pesticide application compared to that needed in corn for seed; hybrid corn for grain 

production has increased vigor and increased resistance to pests and diseases of hybrid 

corn varieties relative to inbred corn lines used in seed production. In some cases, choice 

of management practice may dictate marketability of a corn product, with certain 

agricultural consumer sectors stipulating requirements and restrictions regarding corn 

production methods. 

Glyphosate-resistant crops have become adopted widely since their introduction in the 

mid-late 1990s for several reasons. Glyphosate works non-selectively on a wide range of 

plant species, is a relatively low-cost herbicide, enhances ‘no-till’ farming practices, and 

has minimal animal toxicological and environmental impact. However, increased 

selection pressure resulting from the wide-spread adoption of glyphosate-resistant crops, 

along with the reductions in the use of other herbicides and weed management practices, 

66
has resulted in both weed population shifts and growing numbers of glyphosate-resistant 

individuals among some weed populations (Owen, 2008; Duke and Powles, 2009). In 

order to respond to the consequences, and to avoid decreased crop yields that result from 

weed competition, growers must continue to adapt their weed management strategies, 

including the use of herbicides with alternative modes of action, including auxin growth 

regulators, amino acid inhibitors, chlorophyll pigment inhibitors, or lipid biosynthesis 

inhibitors (Ross and Childs, 2011). 

The EPA’s assessment of herbicide usage in cornfields showed that the use of glyphosate 

increased dramatically from 1987 to 2001; by comparison, 2,4-D usage remained 

essentially unchanged during that time (Kiely et al., 2004). In 2005, 77 different 

herbicides were applied to 97% of corn acreage planted in 19 states representing 93% of 

all corn planted in the U.S (USDA-NASS, 2006). In the 2010 follow-up to that survey, 

the herbicide most widely used on corn was glyphosate, rather than atrazine as in the 

2005 survey, although atrazine was still used on the majority of corn acres; metolachlor 

and acetochlor remained at the same relative usage rates (USDA-NASS, 2011a). 

Table 4-1: Changes in Major Herbicide Use between 2005 and 2010

Herbicide 2005 million #

herbicide

2005 % acres 

treated

2010 million #

herbicide

2010 % acres 

Treated

Atrazine 75 66 51 61

Glyphosate 25 31 64 76

Metolachlor 26 23 22 24

Acetochlor 30 23 28 25

Crop rotation in corn is conducted to optimize soil nutrition and fertility, reduce pathogen 

loads, and control corn pests (IPM, 2004; IPM, 2007). Crop rotation practices have been 

described previously in Section 2. 

No Action Alternative: Agronomic Practices

Under the No Action Alternative, corn agronomic practices, as described in Section 2.1.2, 

involving the application of external inputs such as fertilizers, fungicides, herbicides, and 

insecticides are expected to remain as practiced today by the farming community. 

Growers will continue to have access to existing nonregulated GE corn varieties, 

including glyphosate-resistant corn, as well as non-GE corn varieties. Growers likely 

will continue to experience the emergence of glyphosate-resistant weeds, requiring 

modifications of crop management practices to address these weeds. These changes may 

involve all of the techniques identified by Beckie (Beckie, 2006b) including applying 

herbicide sequences, selecting and deploying herbicide mixtures, employing maximal 

herbicide rates, making special applications to resistant weed sites, altering cropping 

systems, using tillage, and controlling weed seed spread. 

67
Current corn management practices are likely to continue under the No Action 

Alternative. Growers will continue to choose certain pesticides based on weed, insect 

and disease pressures, cost of seed and other inputs, technology fees, human safety, 

potential for crop injury, and ease and flexibility of the production system, (Heiniger, 

2000; Farnham, 2001; University-of-Arkansas, 2008). No-till production of corn will 

continue to increase under the No Action Alternative, effectively mitigating the negative 

impacts of conventional tillage and associated soil erosion (Fawcett and Caruana, 2001). 

Agronomic practices involving the application of external inputs, such as herbicides, 

pesticides, and moisture, will remain as it is practiced today. 

Under the No Action Alternative, growers likely will continue to experience the 

continued emergence of glyphosate-resistant weeds, requiring modifications of crop 

management practices to address these challenges, including the use of alternative 

herbicides for weed control, mechanical cultivation practices (Benbrook, 2009b).

Typical of the types of management for field corn in Iowa is the listing of 13 herbicides 

used pre-emergence in sequence with glyphosate, 17 applied post-emergence as a tank 

mixture with glyphosate, and use of Ignite with Liberty Link hybrids (Iowa-StateUniversity, 2012).In addition, 54 herbicide premixes or co-packs were cited, some 

containing different herbicides than would be sold individually for application to corn 

(Iowa-State-University, 2012), Numerous options exist for use of herbicides with a mode 

of action different from glyphosate, to either respond to glyphosate resistant weeds, or to 

deter development of such weeds. 

Any effects due to crop rotation, tillage, and pesticide use in the agricultural production 

of seed corn and commercial corn will remain the same under the No Action Alternative. 

Rotation strategies for corn under the No Action Alternative will continue as practiced 

today, with market demand and available technology strongly influencing corn rotation 

practices. 

Preferred Alternative: Agronomic Practices

A determination of nonregulated status of VCO-01981-5 corn is not expected to result in 

changes in the current corn cropping practices, because this glyphosate resistant corn trait 

is already a large part of the commercial market for seed corn. APHIS has determined 

that there are no actions that would aggregate with effects of the proposed action to effect 

changes in crop rotation, tillage, or agronomic inputs. Genective’s studies demonstrate 

VCO-01981-5 corn is essentially indistinguishable from other corn varieties used in 

terms of agronomic characteristics and cultivation practices (Genective, 2012; USDAAPHIS, 2012a). Thus, glyphosate application timing, frequency or rates would not be 

expected to change from current levels. Options for use of numerous herbicides to either 

respond to existing glyphosate resistant weeds or to deter their development will continue 

to be available to growers that are deploying the VCO-01981-5 corn with glyphosate 

resistance. Strategies to manage weeds and deter future weed resistance, in addition to 

herbicide use, will also be available to growers, so that cultural control as well as tillage 

options will continue to be used by corn producers.

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4.2.3 Organic Corn Production

Organic production plans prepared pursuant to the National Organic Program (NOP)

include practical methods to protect organically-produced crops from accidental 

contamination with GE materials. The natural cross-pollination of GE corn with organic 

corn is a concern for some organic growers (Coulter et al., 2010). Typically, organic 

growers use more than one method to prevent unwanted material from entering their 

fields including: isolation of the farm; physical barriers or buffer zones between organic 

production and non-organic production; planting border or barrier rows to intercept 

pollen; changing planting schedules to ensure flowering at different times; and formal 

communications between neighboring farms (NCAT, 2003; Baier, 2008; Roth, 2011). 

These practices follow the same system utilized for the cultivation of Certified seed under 

the AOSCA procedures. During the cultivation period, cross-pollination is managed by 

recognizing corn pollen dispersal patterns and maintaining adequate distances between 

fields (Thomison, 2009; Mallory-Smith and Sanchez-Olguin, 2010). A minimum 

isolation distance of 250 feet between varieties is recommended; whereas, 700 feet is 

preferred for complete isolation (Diver et al., 2008). 

APHIS recognizes that producers of non-GE corn, particularly producers who sell their 

products to markets sensitive to GE traits (e.g., organic or some export markets), 

reasonably can be assumed to be using practices on their farm to protect their crop from 

unwanted substances and thus maintain their price premium. APHIS will assume that 

growers of organic corn are already using, or have the ability to use, these common 

practices as APHIS’s baseline for the analysis of the alternatives.

Organic corn acreage has increased over time concurrent with the increase in GE corn 

cultivation. Since 1995, organic corn acreage has increased from approximately 32,000 

acres to over 194,000 acres in 2008 (USDA-ERS, 2011g). Since its introduction in 1995, 

GE corn is now cultivated on over 88% of the U.S. acreage (USDA-NASS, 2012a). This 

concurrent growth of organic crops and GE corn is indicative of the successful adoption 

of these coexistence strategies. Historically, organic corn production represents a small 

percentage (approximately, 0.2%) of total U.S. corn acreage (USDA-ERS, 2011g). The 

percentage of corn acreage dedicated to organic corn is not anticipated to change under 

either the No Action or the Preferred Alternative.

No Action Alternative: Organic Corn Production

Current availability of seed for conventional (both GE and non-GE) corn varieties, and 

those corn varieties that are developed for organic production, is expected to remain the 

same under the No Action Alternative. Commercial production of conventional and 

organic corn is not expected to change and likely will remain the same under the No 

Action Alternative. Organic growers are already coexisting with commercial production 

of conventional and GE corn. The grower strategies employed to support this coexistence 

are not expected to change and likely will remain the same under the No Action 

Alternative. Planting and production of GE, non-GE, and organic corn will continue to 

fluctuate with market demands, as it has over the last 10 years, and these markets are 

likely to continue to fluctuate under the No Action Alternative (USDA-ERS, 2011e; 

USDA-ERS, 2011h). 

69
It is important to note that the current NOP regulations do not specify an acceptable 

threshold level for the presence of GE materials in an organic-labeled product. The 

unintentional presence of the products of excluded methods will not affect the status of an 

organic product or operation when the operation has not used excluded methods and has 

taken reasonable steps to avoid contact with the products of excluded methods as detailed 

in their approved organic system plan (Ronald and Fouche, 2006; USDA-AMS, 2010). 

However, certain markets or contracts may have defined thresholds which growers need 

to attain (Non-GMO-Project, 2012).

Preferred Alternative: Organic Corn Production

GE corn lines including those that are herbicide-resistant are already in use by farmers. 

VCO-01981-5 corn should not present any new and different issues and impacts for 

organic and other specialty corn producers and consumers. 

Organic producers employ a variety of measures to manage identity and preserve the 

integrity of organic production systems (NCAT, 2003). The trend in the cultivation of 

GE corn, non-GE, and organic corn varieties, and the corresponding production systems 

to maintain varietal integrity, are likely to remain the same as the No Action Alternative.

According to the petition, agronomic trials conducted in 2008 in a variety of locations in 

the U.S. demonstrated that VCO-01981-5 corn is not significantly different in plant 

growth, yield, and reproductive capacity from its nonGE counterpart (USDA-APHIS, 

2012a). No differences were observed in pollen diameter, weight, and viability. 

Therefore, VCO-01981-5 corn is expected to present a no greater risk of cross-pollination 

than that of existing corn cultivars. The practices currently employed to preserve and 

maintain purity of organic production systems would not be required to change to 

accommodate the production of VCO-01981-5 corn. 

Historically, organic corn production represents a small percentage (approximately, 

0.2%) of total U.S. corn acreage (USDA-ERS, 2011h). It likely would remain small 

regardless of whether new varieties of GE or non-GE corn varieties, including VCO01981-5 corn, become available for commercial corn production. 

Accordingly, a determination of nonregulated status of VCO-01981-5 corn is not 

expected to have a significant impact on organic corn production.

4.3 Physical Environment

Agricultural production of corn may affect segments of the physical environment 

including, but not limited to water resources, soil quality, air quality, and climate change 

(USDA-ERS, 2005; USDA-ERS, 2010b).

4.3.1 Water Resources

No Action Alternative: Water Resources

70
Under the No Action Alternative, current land acreage and agronomic practices, 

including irrigation, tillage, and nutrient management associated with corn production 

would not be expected to change. Growers would continue to cultivate glyphosate 

resistant varieties already on the market and continue the agronomic practices and inputs 

associated with those varieties. These practices and inputs would include the use of 

glyphosate as an herbicide as part of the weed management strategy. No expected 

changes to water use associated with corn production is expected for this alternative. 

As discussed in Subsection 4.2.1, Acreage and Area of Corn Production, corn is expected 

to continue to be a major crop in the U.S., with a predicted increase in production from 

approximately 88 million acres of land in 2010 to between 90 and 92 million acres 

through 2020 (USDA-OCE, 2011a). Current agronomic practices associated with corn 

production that have potential to impact water quality or quantity include tillage, 

agricultural inputs such as fertilizer and pesticide use, and irrigation. The majority of 

herbicide-resistant corn grown in the U.S. is glyphosate-resistant (Duke and Powles, 

2009). 

As discussed above in Subsection 4.3.2, Soil Quality, more diverse weed management 

tactics, potentially including more aggressive tillage practices that can affect soil erosion,

may be needed to address the increasing emergence of glyphosate-resistant weeds 

(Beckie, 2006b; Owen et al., 2011; Owen, 2011a). Increased tillage could result in more 

soil erosion that could consequently increase sedimentation and residual pollutant loading 

of nearby waters. The particular mix of weed management tactics selected by an 

individual producer, however, are dependent upon many factors such as the 

agroecological setting, the problem weed type, and agronomic and socioeconomic factors 

important to farmers (Beckie, 2006b). As discussed in Subsection 2.2.1, Water 

Resources, fertilizer and pesticide use has the potential to impact water quality. In 2010, 

fertilizer (primarily nitrogen) was applied to the majority of corn acres, and herbicides 

applied to 98% of planted corn (USDA-NASS, 2011c). Of the treated acres, glyphosate 

was the most commonly applied herbicide active ingredient that year (USDA-NASS, 

2011c). When used consistent with registered uses and EPA-approved labels, glyphosate 

presents minimal risk to surface and groundwater. Irrigation from surface and subsurface 

sources can reduce water quantity and impact water quality by the used water acquiring 

increased sediment, nutrients, and chemicals adsorbed to soil that is subsequently leached 

to groundwater, or returned to surface water. Recent estimates indicate only about 11.0%

of corn acreage was irrigated in the U.S in 2010.(NCGA, 2011). 

Preferred Alternative: Water Resources

VCO-01981-5 corn’s nonregulated status under the Preferred Alternative would present 

another glyphosate-resistant corn and weed management option to farmers. It is expected 

VCO-01981-5 corn would replace other glyphosate-resistant corn varieties and, therefore, 

not change the overall acreage or area of corn production in the U.S. that potentially 

impacts water resources through sedimentation and residual pollutant loading from 

runoff. As discussed in Subsection 4.2.1, Acreage and Area of Corn Production, 

herbicide-resistant corn comprised 73% of all planted corn acreage in 2012 and the 

majority of herbicide-resistant corn is glyphosate resistant (Duke and Powles, 2009; 

USDA-NASS, 2012a). As VCO-01981-5 corn is similar in its growth and agronomic 

71
characteristics to its control cultivars and other nonregulated glyphosate-resistant maize 

lines (USDA-APHIS, 2012a), no changes to irrigation and other agronomic practices 

such as fertilizer and pesticide applications, including herbicides, that have the potential 

to affect water quality or quantity, would occur as a result of this alternative. 

Since planted VCO-01981-5 corn is expected to replace other glyphosate-resistant corn 

acreage, its nonregulated status would not affect the recent trend to broaden weed 

management practices, including more tillage that may increase erosion, and thereby 

sediment loading to surface waters. The impacts of the Preferred Alternative to water 

resources, therefore, would be the same as the No Action Alternative. 

4.3.2 Soil Quality

No Action Alternative: Soil Quality

Land acreage and agronomic practices associated with conventional corn production are 

not expected to change in response to the No Action Alternative. 

Agronomic practices associated with GE and non-GE corn crop production that benefit 

soil quality include contouring, use of cover crops to limit the time soil is exposed to 

wind and rain, introduce certain soil nutrients, crop rotation, and windbreaks. Other 

agronomic practices utilized in non-GE and GE corn production that potentially impact 

soil quality include tillage for crop establishment, fertilizer, weed control, and pesticide 

application.

The production of conventional herbicide-resistant GE corn utilizes EPA-registered 

pesticides for insect and plant pest management, including glyphosate. In 2010, 

herbicides were applied to 98% of cropland planted to corn (USDA-NASS, 2011c). 

Pesticides (including herbicide, insecticide, and fungicide) consist of active ingredients 

that control pests and inert ingredients to facilitate their application. In 2010, 66% of all 

active ingredients applied to corn treated with pesticides were herbicidal (USDA-NASS, 

2011c), indicating their widespread use and potential to affect the environment The 

amount of herbicides other than glyphosate applied to corn has declined over the last 

decade (NRC, 2010b) (see Subsection 4.2.2, Agronomic Practices). The environmental 

risks of pesticide use are assessed by the EPA in the pesticide registration process and are 

regularly re-evaluated by the EPA to maintain their registered status under FIFRA. In 

this process, steps to reduce pesticide residuals and persistence in soil are included on a 

pesticide’s label and approved by the EPA. 

As discussed in Subsection 2.2.2, Soil Quality, there have been several reports of the 

long-term use of glyphosate immobilizing manganese and potentially reducing plant 

uptake or ability to utilize this nutrient (Eker et al., 2006; Neumann et al., 2006; Ozturk et 

al., 2008; Cakmak et al., 2009; Huber, 2010). Additional investigations are required to 

determine the scope and characterization of glyphosate interactions with nutrients. The 

current understanding is manganese-glyphosate interaction resulting in manganese 

problems appears to occur in areas where manganese deficiency already exists (Hartzler, 

2010), and producers can address it with agronomic practices designed to augment 

manganese (Camberato et al., 2010).

72
The development of glyphosate-resistant weeds or weed management tillage practices 

potentially impact soil quality. A variety of strategies should be utilized in addressing 

glyphosate-resistant weeds, including applying the right strength of herbicide, rotating 

herbicide modes of action, crop rotation, spot treatments, vigilant scouting, and hand 

weeding (Gunsolus, 2002; Sellers et al., 2011). In the long term, more diverse weed 

management tactics potentially including more aggressive tillage practices that can affect

soil quality may be needed to address the increasing emergence of glyphosate-resistant 

weeds (Beckie, 2006a; Owen et al., 2011; Owen, 2011a). The particular mix of weed 

management tactics selected by an individual producer is dependent upon many factors, 

including the agroecological setting, the problem weed type, and agronomic and 

socioeconomic factors important to farmers (Beckie, 2006b).

Preferred Alternative: Soil Quality

Approving the petition for a determination of nonregulated status to VCO-01981-5 corn

would not affect soil quality. VCO-01981-5 corn would likely replace other 

commercially available glyphosate-resistant corn cultivars because most corn acreage is 

currently planted to either herbicide-resistant-only corn or herbicide-resistant corn 

varieties stacked with other GE traits (Duke and Powles, 2009; USDA-NASS, 2012a). 

The area and acreage of corn production potentially impacting soil quality would not 

change as a result of the Preferred Alternative. 

VCO-01981-5 corn is agronomically and compositionally equivalent to other glyphosate 

resistant corn, and other GE and non-GE corn varieties currently in commercial 

production (Genective, 2012; USDA-APHIS, 2012a). Agronomic practices such as 

tillage and the application of agricultural chemicals that could impact soil quality or its 

community structure and function would not change from those currently used for 

production of other nonregulated glyphosate-resistant corn varieties. 

Since it is expected to replace other glyphosate-resistant cultivars, the nonregulated status 

of VCO-01981-5 corn would not affect weed management practices or their effects on 

soil quality. As discussed above, more diverse weed management tactics potentially 

including more aggressive tillage practices that can affect soil quality may be needed to 

address the increasing emergence of glyphosate-resistant weeds (Beckie, 2006b; Owen et 

al., 2011; Owen, 2011a). As described under the No Action Alternative, the weed 

management tactics selected by an individual producer would be dependent upon many 

factors (Beckie, 2006b). Weed management practices needed for the production of VCO01981-5 corn would be no different than those used in other commercially available 

glyphosate-resistant corn cultivars. 

Under the Preferred Alternative, the amount of herbicides other than glyphosate applied 

to corn would likely continue to decline as they have for the last decade (NRC, 2010a)

(see Subsection 4.2.2, Agronomic Practices). The application of glyphosate is not 

expected to change as a result of approving VCO-01981-5 corn’s nonregulated status, as 

no change in the registered use or label of this herbicide is proposed and, as discussed in 

Subsection 4.2.1, Acreage and Area of Corn Production, the cultivar is anticipated to 

replace other glyphosate-resistant corn varieties. As discussed above, the impact of 

glyphosate on manganese availability for uptake by crops after its application is an issue 

73
that may be addressed with common practices used to augment deficient soil nutrients. 

VCO-01981-5 corn is agronomically similar to other GE and non-GE corn varieties and 

would most likely replace other glyphosate-resistant varieties, the same methods used to 

address manganese deficiency in current corn production would also be used with VCO01981-5 corn; therefore, impacts to soil quality under the Preferred Alternative would be 

the same as the No Action Alternative.

4.3.3 Air Quality

No Action: Air Quality 

Under the No Action Alternative, current impacts to air quality associated with land 

acreage and cultivation practices associated with corn production are not likely to be 

affected. 

Corn is the most widely produced feed grain in the U.S., so its production practices can 

substantially impact air quality. Tillage prepares the ground for planting, may control 

weeds, incorporates nutrients and herbicides into soil, and is useful for other functions 

such as controlling water flow through a field (see Subsection 2.1.2, Agronomic 

Practices). Tillage exposes soil to wind erosion and utilizes motorized equipment that 

produces emissions. To the extent that the adoption and cultivation of GE corn varieties 

allows the grower to adopt conservation tillage practices (Towery and Werblow, 2010a), 

air quality improvement associated with these practices would be expected to follow. 

The USDA reports that in 2010, up to 74.5% of planted corn acres were produced under 

conservation tillage practices ranging from no-till to reduced till (USDA-ERS, 2011d). 

Reduced tillage generates fewer particulates (dust) and potentially contributes to lower 

rates of wind erosion releasing soil particulates into the air, benefitting air quality 

(Fawcett and Towery, 2002). Conservation tillage also reduces equipment emissions due 

to decreased usage. More recently, these benefits may be eroding if growers employ 

more aggressive tillage to control the increasing resistance of weeds to herbicides, 

including glyphosate-resistant weeds (Beckie, 2006b; Owen et al., 2011; Owen, 2011a). 

Weed management methods, however, vary from farm to farm, dependent upon the 

agroecological setting, the problem weed type, and agronomic and socioeconomic factors 

important to farmers (Beckie, 2006b). 

Pesticide application in corn production has the potential to impact air quality while 

actively applied through spray drift, afterward by volatilization off of plant and soil 

surfaces, and by windborne soil containing residuals in areas where a pesticide has been 

dispensed (see Subsection 2.2.3, Air Quality, for detailed discussion). Glyphosate is the 

most common herbicide active ingredient applied to herbicide-treated corn in the U.S. 

(USDA-NASS, 2011c). The EPA is currently evaluating new regulations for pesticide 

drift labeling and the identification of BMPs to control such drift (US-EPA, 2009e), as 

well as identifying scientific issues surrounding field volatility of conventional pesticides 

(US-EPA, 2010b). Agricultural production of existing nonregulated GE and 

conventional corn mostly require EPA-registered pesticides for insect and plant pest 

management, including glyphosate. Glyphosate has a low vapor pressure and volatility 

from soils (US-EPA, 1993b). Glyphosate’s EPA-approved label provides measures for 

minimizing the potential air quality impacts from its use. When used in accordance with 

74
registered uses and EPA-approved labels, glyphosate poses minimal risks to air quality. 

Increasing or decreasing the acreage of corn production and its associated agronomic 

practices with emissions potentially impact air quality. As discussed in Subsection 4.2.1, 

Acreage and Area of Corn Production, corn is a major crop in the U.S., expected to 

maintain current production levels through 2020 (USDA-OCE, 2011a). Global market 

forces determine the price of corn, which in turn affects grower decisions on how much 

to plant (USDA-OCE, 2011a).

Air quality will continue to be affected by current agronomic practices associated with 

conventional methods of corn production such as tillage, cultivation, pesticide and 

fertilizer applications, and the use of agricultural equipment.

Preferred Alternative: Air Quality

VCO-01981-5 corn is agronomically and compositionally equivalent to its control 

cultivars, and other GE and conventional corn varieties currently in commercial 

production (Genective, 2012; USDA-APHIS, 2012a). No changes to agronomic 

practices that are sources of emissions or positively contribute to air quality such as the 

amount, type and timing of tillage, equipment use, irrigation, and the application of 

fertilizers or pesticides would result from determining VCO-01981-5 corn nonregulated. 

The commercial use of glyphosate is expected to remain the same if VCO-01981-5 corn 

were determined nonregulated, since the cultivar would replace other glyphosate-resistant 

corn varieties, and no changes to glyphosate’s registered use or label are proposed. 

Approximately 73% of planted corn in the U.S. is herbicide resistant, and of that, most is 

glyphosate resistant (Duke and Powles, 2009; USDA-NASS, 2012a) (see Subsection 

4.2.1, Acreage and Area of Corn Production, for detailed discussion). 

VCO-01981-5 corn would not likely change the development of glyphosate-resistant 

weeds or the methods used for their control that may impact air quality, since it is 

expected to replace other glyphosate-resistant corn cultivars. In summary, there are no 

new impacts to air quality posed by a determination of nonregulated status for VCO01981-5 corn. The potential impacts to air quality under the Preferred Alternative are, 

therefore, similar to the No Action Alternative.

4.3.4 Climate Change

No Action Alternative: Climate Change

Current agronomic practices associated with conventional corn production and current 

GE corn varieties which contribute to GHG emissions, including tillage, cultivation, 

irrigation, pesticide application, fertilizer applications, and use of agriculture equipment, 

are not expected to change if VCO-01981-5 corn remains a regulated article. Land 

acreage and cultivation practices associated with corn production would not be affected. 

To the extent that the adoption and cultivation of GE corn varieties allows the grower to 

implement conservation practices, GHG emissions are expected to continue to be reduced 

commensurate with the air quality improvements anticipated from adoption of 

conservation tillage practices.

75
The major sources of GHG emissions associated with crop production are soil N2O 

emissions, soil CO2 and CH4 fluxes, and CO2 emissions associated with agricultural 

inputs and farm equipment operation (US-EPA, 2012a). Agricultural practices that 

produce CO2 emissions include liming and the application of urea fertilization (i.e., 

nitrogen) to agricultural soils, and CH4 produced by enteric fermentation and animal 

manure management. Agricultural soil management activities including fertilizer 

application and cropping practices are the largest source of N2O emissions in the U.S. 

(US-EPA, 2012a). Corn crop production primarily affects climate-changing emissions 

through: (1) fossil fuel burning equipment used for production and nitrogen fertilization 

producing CO2; and, (2) cropping production practices including residue management 

and tillage (see Subsection 2.2.4, Climate Change, for detailed discussion). The adoption 

of herbicide-resistant crops and the attendant increase in conservation tillage has been 

identified as providing climate change benefits. Conservation tillage practices increase 

crop residue on the surface, promoting the production of SOC and protecting the soil 

from erosive forces that would release SOC back to the air. These practices also reduce 

the use of emissions-producing equipment normally used in tilling. The USDA has 

estimated approximately 74.5% of planted corn acres in 2010 were produced under 

conservation tillage practices ranging from no-till to reduced till (USDA-ERS, 2011d). 

Recent increases in the incidence of herbicide-resistant weeds, including glyphosate, may 

require increased tillage to effect control (Beckie, 2006b; Owen et al., 2011; Owen, 

2011a). This could potentially release more SOC sequestered in upper soil layers; 

however, the particular weed management methods employed by individual farmers 

would be dependent on many factors unique to the individual farm, including its 

agroecological setting, the particular problem weed type, and on-farm economics

(Beckie, 2006b).

Nitrogen is also the most-used fertilizer in U.S. corn production (USDA-NASS, 2011c). 

Nitrogen in the form of urea is commonly applied to cornfields and contributes CO2

emissions from the urea volatilization which also produces ammonia. Recommended 

BMPs to reduce volatilization include incorporating urea with equipment, accompanied 

with irrigation or rainfall; topdressing urea when temperatures and soil moisture levels 

are low; and avoiding topdressing urea in higher risk conditions, except if there is an 

opportunity to incorporate the urea within a few days of application (Jones et al., 2007).

Impacts of climate change are apparent in Corn Belt states at the present time. For 

example, in Iowa precipitation totals are significantly increasing and summers have 

increasing incidents of heavy precipitation (Iowa-General-Assembly, 2011). 

Consequently, farmers are installing increasing amounts of drain tile to respond to 

increased flooding of fields (Iowa-General-Assembly, 2011). With increased drain tiling, 

greater nitrate-nitrogen losses are incurred (David et al., 2010; Iowa-General-Assembly, 

2011). Weeds have increased and more pesticides are used which accompanies reduced 

herbicide efficacy (Iowa-General-Assembly, 2011). Delayed planting and increased 

replanting attend increased heavy precipitation (Iowa-General-Assembly, 2011). 

Because the growing season has increased, growers have begun to use corn maturity 

groups suitable for lower latitudes, which may increase the yield (E. Takle, Iowa State 

University, USDA Climate Change Seminar, Pers. Comm. 2012 (Krapfl, 2012). As 

76
climate change begins to be manifest in additional US corn growing regions, growers will 

continue to make accommodations to maintain production and yield. 

Preferred Alternative: Climate Change

Because corn line VCO-01981-5 is similar to other GE and non-GE corn cultivars in 

terms of its growth habit, agronomic properties, disease susceptibility, and composition 

(USDA-APHIS, 2012a), the agronomic practices required to cultivate corn line VCO01981-5 would be no different than those used to produce other herbicide-resistant corn 

cultivars. Therefore, no changes to agricultural practices that could affect GHG 

emissions would be expected from determining nonregulated status for VCO-01981-5. 

To the extent that the cultivation of a corn variety expressing resistance to glyphosate 

allows a grower to minimize conventional tillage and increase the adoption of 

conservation tillage practices, the potential impacts associated with the Preferred 

Alternative would be the same as those under the No Action Alternative.

Because corn line VCO-01981-5 is another glyphosate-resistant cultivar similar to other 

commercially available glyphosate-resistant corn varieties, and the majority of planted 

corn in the U.S. is herbicide resistant (73% in 2012) primarily consisting of glyphosateresistant cultivars (Duke and Powles, 2009; USDA-NASS, 2012a), it would likely replace 

other glyphosate-resistant cultivars rather than expand the production of glyphosateresistant cultivars. Conferring nonregulated status to corn line VCO-01981-5 would not 

likely change the development of glyphosate-resistant weeds, since it is expected to 

replace other glyphosate-resistant corn acreage; thus, no change to GHG emissions would 

occur from use of fossil fuels, release of SOC, or carbon sequestration in plant residue 

and soils under the Preferred Alternative. As discussed under the No Action Alternative 

above, more diverse weed management tactics, potentially those including more 

aggressive tillage practices that can affect GHG emissions, may be needed in the long 

term to address the increasing emergence of glyphosate-resistant weeds (Beckie, 2006b; 

Owen et al., 2011; Owen, 2011a). Since corn line VCO-01981-5 is expected to replace 

other glyphosate-resistant cultivars, its nonregulated status would not alter weed 

management practices and their effects on GHGs contributing to climate change; 

therefore, the potential impacts to climate change under the Preferred Alternative would 

be similar to the No Action Alternative.

4.4 Biological Resources

4.4.1 Animal Communities

No Action Alternative: Animal Communities

Under the No Action Alternative, conventional and GE corn production will continue as 

currently practiced while VCO-01981-5 corn remains a regulated article. This includes 

the cultivation of other glyphosate-resistant corn varieties. Potential impacts of GE and 

non-GE corn production practices on non-target terrestrial (insect, bird, and mammal) 

and aquatic (fish, benthic invertebrate, and herptile) species would be unchanged. 

77
Corn production potentially impacts animal communities through the conversion of 

wildlife habitat to agricultural purposes. As discussed in Subsection 2.2., Acreage and 

Area of Corn Production, corn was produced on over 96 million acres in 2011, an 

increase of approximately 4.5 million acres over 2011 (USDA-NASS, 2012a). Corn is 

expected to continue to be a major crop in the U.S. through 2020 (USDA-OCE, 2011a). 

A wide array of wildlife occupy or use habitats that are within or adjacent to cornfields 

(see Subsection 2.3.1, Animal Communities). While cornfields are less suitable for 

wildlife than adjacent pasture, fallow fields, windbreaks, or shelterbelts, those in 

conservation tillage management provide greater benefit for wildlife than those in more 

intensive tillage Under this tillage regime, greater diversity in plant species would occur

and so provide more habitat and potential food sources, soil would be less disturbed, and 

potentially sediment and agricultural pollutant loading of nearby surface waters would be 

reduced, improving water quality (Brady, 2007; Sharpe, 2010).

Glyphosate-resistant corn varieties have been approved as nonregulated since 1997 

(USDA-APHIS, 2012b), and the majority of corn cultivated today is herbicide resistant 

(USDA-ERS, 2011a), primarily glyphosate-resistant (Duke and Powles, 2009). All 

glyphosate-resistant corn varieties currently available on the market have been evaluated 

for their food and feed safety impacts by the FDA. The EPSPS protein that confers 

glyphosate resistance in GA21 (similar to VCO-01981-5 corn) is corn-derived, and 

99.3% identical to its non-herbicide-resistant corn comparators (Monsanto, 1997). This 

EPSPS has been earlier evaluated by the FDA, who found no safety concerns from its 

consumption as animal feed (US-FDA, 1998). The EPSPS from VCO-01981-5 corn is 

derived from the soil inhabiting species, Arthrobacter globiformis, which is not a plant 

pest. Consumption of nonregulated glyphosate-resistant corn presents minimal risk to 

animal communities. A final food and feed consultation with the FDA for VCO0198101851-5 corn was submitted by Genective on March 5, 2012 (to be noted as BNF00137). FDA is presently evaluating the submission and it is still pending.

Current corn agronomic practices potentially impacting animal communities include 

application of agricultural inputs, such as fertilizer, herbicides, and pesticides. Both 

fertilizer and pesticides are applied to the majority of corn acres in the U.S. (USDANASS, 2011c) and potentially impact non-target wildlife from ingestion or spray drift. 

Glyphosate is the primary herbicide applied to herbicide-treated corn acreage in the U.S. 

(USDA-NASS, 2011c). As discussed in Subsection 2.1.2, Agronomic Practices, there are 

several glyphosate formulations (US-EPA, 2009c) that differ in the timing and amount of 

application to field corn. The environmental risks of glyphosate herbicides are assessed 

by the EPA in the pesticide registration process. The glyphosate is currently undergoing 

registration review scheduled for the final decision in 2015 (US-EPA, 2009b). As 

discussed in Subsection 2.3.1, Animal Communities, the registered uses for glyphosate 

pose minimal risk to animals, but spray drift may adversely impact non-target plants that 

provide habitat. When used consistent with the EPA-registered uses and labels, 

glyphosate application in corn presents minimal risk to animal communities. In 2010, 

66% of all active ingredients applied to corn treated with pesticides were herbicidal 

(USDA-NASS, 2011c).

More diverse weed management tactics potentially including more aggressive tillage 

78
practices that can affect animal communities may be needed to address the increasing 

emergence of glyphosate-resistant and other herbicide-resistant weeds , (Beckie, 2006b; 

Owen et al., 2011; Owen, 2011a). As discussed above, more intensive tillage can reduce 

wildlife habitat and contribute to increased sedimentation and pollutants in runoff to 

nearby surface waters, affecting water quality that could impact wildlife. The particular 

mix of weed management tactics selected by an individual producer would be dependent 

upon many factors, including the agroecological setting, the problem weed type, and 

agronomic and socioeconomic factors important to farmers (Beckie, 2006b). 

Preferred Alternative: Animal Communities

Glyphosate-resistant corn varieties have been deregulated since 1997 (USDA-APHIS, 

2012b), and the majority of corn cultivated today is herbicide resistant (USDA-ERS, 

2011a), primarily glyphosate-resistant (Duke and Powles, 2009). All glyphosate-resistant 

corn varieties currently available on the market have been evaluated for their food and 

feed safety impacts by the FDA. The EPSPS protein that confers glyphosate resistance in 

GA21 (similar to VCO-01981-5 corn) is corn-derived, and 99.3% identical to its nonherbicide-resistant corn comparators (Monsanto, 1997). This EPSPS has been earlier

evaluated by the FDA, who found no safety concerns from its consumption as animal 

feed (US-FDA, 1998). Similarly, the cp4 epsps now expressed in numerous glyphosate 

resistant corn and soybean varieties has been evaluated by the FDA, who likewise agreed 

that these are not materially different in composition, safety, and other relevant 

parameters from corn grain and forage currently on the market (US FDA BNF-000071)

The EPSPS from VCO-01981-5 corn is derived from the soil inhabiting species, 

Arthrobacter globiformis. A final food and feed consultation with the FDA for VCO0198101851-5 corn was submitted by Genective on March 5, 2012 (to be noted as BNF00137). FDA is presently evaluating the submission and it is still pending.

As part of the assessment for the proposed action, APHIS has evaluated the potential 

effects of each alternative on a wide array of wildlife species and their habitats occurring 

in the U.S. Under the Preferred Alternative, VCO-01981-5 corn may be available as 

another glyphosate-resistant corn as a weed management option for farmers. As stated 

above, the majority of corn planted in the U.S. today is herbicide resistant (Duke and 

Powles, 2009; USDA-ERS, 2011a). As such, it is expected that VCO-01981-5 corn will 

be another option to other currently available glyphosate-resistant corn varieties and 

would replace these varieties and not change the acreage or area of corn production in the 

U.S. (see Subsection 4.2.1, Acreage and Areas of Corn Production). VCO-01981-5 corn 

is similar in its growth and agronomic characteristics to other nonregulated glyphosateresistant corn lines (Genective, 2012; USDA-APHIS, 2012a); hence, no changes to 

agronomic practices such as cultivation, crop rotation, irrigation, tillage, or agricultural 

inputs with potential impacts to wildlife and their habitat would likely occur under this 

alternative. 

As discussed in Subsection 2.5, Animal Feed, a final food consultation with the FDA for 

VCO-01981-5 corn was submitted by Genective on March 5, 2012 (BNF-00137). FDA is 

presently evaluating the submission. As discussed in the No Action Alternative, the food 

safety of the EPSPS protein conveying glyphosate resistance was previously established 

79
by an FDA early food safety evaluation. Because the composition of VCO-01981-5 corn 

is similar to other nonregulated glyphosate-resistant corn lines (Genective, 2012), with no 

expected hazards associated with its consumption, the risk of VCO-01981-5 corn 

affecting wildlife species is also unlikely, regardless of exposure. 

Commercial use of glyphosate is not expected to change if the petition for nonregulated 

status of VCO-01981-5 corn is approved. Based upon information provided by 

Genective (Genective, 2012), VCO-01981-5 corn is similar in its growth characteristics 

to other nonregulated glyphosate-resistant corn. No changes to the registered uses or 

labels of glyphosate products would be required to cultivate VCO-01981-5 corn. 

Consequently, there would be no difference in the potential of VCO-01981-5 corn 

cultivation to impact wildlife or habitat from that of other nonregulated glyphosateresistant corn varieties. When used consistent with the EPA-registered uses and labels, 

glyphosate application in VCO-01981-5 corn fields presents minimal risk to animal 

communities. 

Approving VCO-01981-5 corn as nonregulated would not change the development of 

glyphosate-resistant weeds or the methods used for their control that may impact animal 

communities, such as increased tillage. As discussed above, VCO-01981-5 corn would 

likely replace other glyphosate-resistant corn cultivars that currently comprise 73% of 

corn cultivars (USDA-NASS, 2012a).

Based on the above, there would be no change in the effects on animal communities from 

the no action alterative if the preferred alternative is adopted. 

4.4.2 Plant Communities

No Action Alternative: Plant Communities

Corn can be grown in a wide number of environments, dependent upon appropriate soil 

profiles, and locations where weather is not limiting (Iowa-State-University, 2002). 

Plants communities are varied and adapted to local climate and soil, as well as the

frequency of natural or human-induced disturbance (Smith and Smith, 2003). Non-crop 

vegetation in cornfields is limited by farmers’ cultivation and weed control practices. 

Plants communities adjacent to cornfields commonly include other crops, borders, 

hedgerows, windbreaks, pastures, and other natural vegetation. The majority of U.S. corn 

acres are planted with GE herbicide-resistant corn cultivars, and genetically engineered 

traits do not change the adaptation to the various agronomic environments in which corn 

hybrids can be produced. 

Agricultural practices affect plant communities by exerting selection pressures that 

influence the type and composition of plants present in a community. Preparation of 

fields for planting of crops removes other plants that compete for light and nutrients. 

Natural selection in frequently disturbed environments enables colonization by plants 

exhibiting early germination and rapid growth from seedling to sexual maturity, and the 

ability to reproduce sexually and asexually (Baucom and Holt, 2009). These weedy 

characteristics enable such plants to spread rapidly into areas undesired by humans. 

Weeds are the most important pest in agriculture, competing for light, nutrients, and 

water and can significantly affect yields (Gibson et al., 2005; Baucom and Holt, 2009).

Weeds commonly encountered in corn production include water hemp, giant ragweed, 

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common lambsquarters, and others as described in Subsection 2.3.2, Plant Communities. 

Agronomic practices common in corn production, such as tillage and herbicide use, 

impart selection pressures on the weed community that can result in shifts in the relative 

importance of specific weeds (Owen, 2008). In aggressive tillage systems, weed 

diversity tends to decline and annual grasses and broadleaf plants are the dominant 

weeds; whereas, in no-till fields, greater diversity of annual and perennial weed species 

may occur (Baucom and Holt, 2009). The most common weed management tactic in 

U.S. corn production is to use herbicides. Recent estimates indicate herbicides are 

applied to 98% of planted corn acreage, and on that acreage, the most frequently applied 

herbicide is glyphosate (USDA-NASS, 2011c). 

Herbicide resistance occurs when a plant survives the application of an herbicide and 

reproduces, passing on its resistance to new generations. Herbicide-resistant weeds can 

become agronomically important as they out-compete crops and require additional 

resources to affect control. As discussed in Subsection 2.3.2, Plant Communities, weed 

species resistant to glyphosate are becoming more prevalent in crop production. For 

example, glyphosate-resistant Palmer pigweed (amaranth) is a major weed problem in the 

Southeast U.S. while glyphosate-resistant waterhemp is a problematic weed in 

Midwestern states (Culpepper et al., 2006; Owen, 2008). In response, producers are 

diversifying weed management tactics in corn production to include alternating crops 

resistant to different herbicide modes of action grown in a field, alternating the herbicide 

modes of action used, practicing more crop rotation, and increasing tillage to effect 

control of herbicide-resistant weeds (Owen et al., 2011). Weeds are developing 

resistance to multiple herbicides, but are also controlled with adjustments to standard 

practices, so as to include crop rotation and tillage (Owen et al., 2011) when overreliance 

on herbicides obviates such changes.

Deterring development of glyphosate resistant weeds is a topic frequently addressed to 

growers by University extension staff, seed developers, and corn producers associations, 

among many others. State specific advice, as for example, in Iowa, has identified 

existing methods that would be highly relevant to corn growers (Owen, 2011a). Owen

(2011a) has noted that simplicity and convenience of depending solely on glyphosate 

“has run its course” and that diversity in weed management strategies (integrated weed 

management) is needed. He calls for (1) use of herbicide tank mixes, with specific 

knowledge of existing weed resistances on the farm (2) redundant herbicides for control 

of key weeds (3) multiple herbicides at each application (4) inclusion of mechanical and 

cultural strategies. Specific weeds of high concern for resistance development such as 

horseweed (Conyza canadensis) have been shown to be effectively controlled by 

combinations of herbicides, such as mesotrione and atrazine and other combinations 

(Armel et al., 2009). Likewise, combinations of these can be used for control of Palmer 

amaranth, common waterhemp, and giant ragweed (see review in Owen

(2011b).Similarly, multistate successes with two or three herbicides pre-emergence have 

been demonstrated for giant ragweed, common lambsquarters, and giant foxtail, which 

build on use of atrazine (Loux et al., 2011). While atrazine is already widely used (see 

Table 2.5) and weed resistance to atrazine is known in Corn Belt states (Heap, 2012), 

some state weed extension staff continue to see a place for its use in corn production 

(Owen, 2011b). The extent of weed resistance in Iowa is yet comparatively small, with 

state-wide estimate of about 1% of acres infested with glyphosate resistant weeds 

81
(Hartzler, 2011) (out of 14 million acres of corn planted in Iowa in 2012 (USDA-NASS, 

2012a). However, some estimates place row crop glyphosate resistant water hemp as 

being found on 20% of Iowa acres (Corn-and-Soybean-Digest, 2013). Corn growers are 

aware that overuse of glyphosate as principle herbicide results in weed resistance 

(multistate survey from 2005: (Givens et al., 2011), and alternative strategies are both 

available and being publicized by a variety of expert resources (as noted in sections 2.3.2 

and 4.4.2). 

For risks of weed resistance to glyphosate, USDA in its various units is funding programs 

aimed at understanding weed resistance development, and managing crops to avoid 

resistance. At the Agricultural Research Service, this includes research programs whose 

goal is providing “recommendations for appropriate rotation frequencies of both crops 

and herbicides to stymie evolution of weed resistance and shifts to naturally tolerant 

weed species, and cause a general reduction in weed populations” as described in the 

Action Plan for 2008-2013 of the National Program 304, Crop Protection and Quarantine 

(USDA-ARS, 2010). The USDA, National Institute of Food and Agriculture (NIFA)

recognizes the need for a broad collaboration of federal, state, academic and industry 

endeavors to provide responses to these and other risks to which agriculture may be 

exposed and provides competitive grant awards, such as those of Westra and Chisolm

(2012) and Davis and Tranel (2012) to support research directed toward weed resistance. 

USDA presently devotes substantial funds to support research, teaching and outreach 

programs (especially through the support of USDA-Extension staff and programs in 

individual States) for herbicide resistance management, and awarded to agricultural 

researchers and growers. Additionally, farmer organizations such as the National Corn 

Growers Association offer online training to their members for averting development of 

weed resistance (http://ncga.adayana.com/). The Weed Science Society of America has 

produced a five-module training course for certified crop protection specialists and others 

titled “Current Status of Herbicide Resistance in Weeds” which is also available online 

(http://www.pentonag.com/wssa.wrm). Seed technology developers such as Monsanto 

offer courses for certified pesticide applicators, such as “Weed Resistance Management 

(WRM) in Agronomic Row Crops & Trees, Nuts & Vines” 

(http://www.pentonag.com/CA/AZWRM). Finally, state extension services also provide 

documents online that supply information and management tactics for prevention of 

herbicide resistance, such as that from University of Minnesota (Gunsolus, 2008).

Volunteer herbicide-resistant arises from spilled corn from the previous cropping season. 

Existing agronomic practices, however, are effective in the management of such 

volunteer corn. Glyphosate-resistant volunteer corn may be controlled by the application 

of corn-active herbicides (e.g., ACCase and ALS inhibitors), mechanical means, and 

rotation of crops with resistance to different herbicide modes of action (Beckie and 

Owen, 2007; Zollinger et al., 2011). 

The application of an herbicide in corn production has the potential to impact non-target 

plant communities through spray drift, volatilization (evaporation), its adsorption to soils 

incorporated in runoff, leaching, and cleaning and disposal of the equipment used to 

dispense it. Glyphosate is toxic to most terrestrial and aquatic plants, inducing plant 

death. The herbicide has low leaching potential, low vapor pressure, and low volatility 

from soils (US-EPA, 1993b; Senseman, 2007) and these properties show low potential 

82
for damage from volatility. In its 1993 glyphosate reregistration decision, the EPA 

required additional studies concerning vegetative vigor, droplet size spectrum, and a drift 

field evaluation that did not affect the reregistration eligibility of the herbicide (US-EPA, 

1993a). The potential effects of glyphosate spray drift are minimized when growers

follow EPA-approved labels that provide detailed measures to manage spray drift; these 

measures include applying only during optimal wind conditions and temperature 

inversions and at appropriate humidity, adjusting spray droplet size and sprayer boom 

heights and including drift reduction additives, and judicious use of aerial spraying from 

aircraft (Monsanto, 2010a). 

In summary, under the No Action Alternative, natural selection, and the selection 

pressure exerted through the use of herbicides and other agronomic practices, impact 

plants communities by either inducing plant death, selecting for weedy characteristics, 

inducing shifts in the composition of the plant community, through gene flow to other 

related plants, and in some cases, contributing to the development of herbicide-resistant 

weeds. Plant species (i.e., weeds) that typically inhabit GE and non-GE corn production 

systems will continue to be managed through the use of mechanical and chemical control 

methods, as currently practiced. Multiple herbicides, including the herbicide glyphosate, 

will continue to be used on corn. 

The reproductive morphology of corn encourages cross-pollination between corn plants 

and there is no evidence (genetic or biological barriers) to indicate that gene flow is 

restricted between genetically modified, conventional, and organic corn. Spatial and 

temporal isolation can be the most effective barriers to gene exchange between corn crop 

cultivars. Requirements and methods to ensure seed and crop purity are discussed in 

more detail in Subsections 2.1.3, Organic Corn Production, and 2.1.4, Specialty Corn 

Production.

Corn does not possess the characteristics for efficient seed-mediated gene flow. Through 

thousands of years of selective breeding by humans, corn has been extensively modified 

to depend on human cultivation for survival (Doebley, 2004). As a result of its 

domestication, corn is not able to survive in the wild and also has several traits that 

greatly reduce its ability to disperse via seeds (OECD, 2003). Corn seed dispersed after 

harvest may survive in fields and develop into volunteer plants, but such volunteers are 

controlled with common agronomic practices (see Subsection 2.3.2, Plant Communities

Preferred Alternative: Plant Communities

Corn line VCO-01981-5 would have no impacts to plants communities adjacent to or 

within agroecosystems that would be different from currently available glyphosateresistant corn cultivars. As discussed in Subsection 4.2.2, Agronomic Practices, the 

agronomic and phenotypic characteristics of VCO-01981-5 have been evaluated in field 

trials (Genective, 2012) and determined by APHIS to be similar to its comparator corn 

cultivars (USDA-APHIS, 2012a). VCO-01981-5 would, therefore, be cultivated 

similarly to other glyphosate-resistant corn, and have impacts to plant communities 

similar to those described under the No Action Alternative.

Nonregulated VCO-01981-5 would not be expected to increase or decrease the 

development of glyphosate-resistant weeds. As another glyphosate-resistant corn cultivar 

option, VCO-01981-5 would likely replace other glyphosate-resistant corn cultivars 

83
without changing the application of glyphosate to corn. No changes to glyphosate’s 

registered uses or labels for the cultivation of VCO-01981-5 are proposed by Genective, 

and no increase in glyphosate-resistant corn production acres is anticipated.

APHIS has determined that there are no phenotypic differences between VCO-01981-5

and control lines that would contribute to enhanced weediness (USDA-APHIS, 2012a). 

Herbicide-resistant corn such as VCO-01981-5 has the potential to impact other crops in 

the same fields or adjacent fields in later seasons as volunteers. As VCO-01981-5 is 

similar to other nonregulated corn cultivars, its volunteers would be controlled by 

common agronomic practices as discussed under the No Action Alternative. 

APHIS evaluated the potential for gene flow between VCO-01981-5 and other corn 

cultivars. Phenotypic testing of VCO-01981-5 and agronomic trials have demonstrated 

the cultivar is similar to other glyphosate-resistant corn varieties (USDA-APHIS, 2012a). 

Therefore, its potential for gene flow and weediness would be no different than other 

corn varieties currently on the market as described under the No Action Alternative.

4.4.3 Microorganisms

No Action Alternative: Microorganisms

Soil microorganisms are important in soil structure formation, decomposition of organic 

matter, toxin removal, nutrient cycling, and most biochemical soil processes (Garbeva et 

al., 2004). They may also suppress soil-borne plant diseases and promote plant growth 

(Doran et al., 1996). As described in Subsection 2.3.3, Microorganisms, the main factors 

affecting microbial population size and diversity include soil and plant type, and 

agricultural management practices (crop rotation, tillage, herbicide and fertilizer 

application, and irrigation) (Garbeva et al., 2004). Plant roots, including those of corn, 

release a variety of compounds into the soil creating a unique environment for 

microorganisms in the rhizosphere. 

Management practices used in corn production can affect soil microorganisms by altering 

microbial populations and activity through modification of the soil environment. An 

agronomic practice may be beneficial for one microorganism but detrimental to another. 

As presented in Subsection 2.3.4, Microorganisms, crop rotation, irrigation, tillage, and 

agricultural chemicals such as fertilizers and pesticides affect microbial community 

structure and functions such as nutrient cycling, disease promotion or suppression, and 

presence in soil. As discussed in Subsection 2.1.2, Agronomic Practices, the adoption of 

glyphosate-resistant corn (and other herbicide-resistant crops) has enabled the use of 

conservation tillage, creating less soil disturbance and retaining more crop residue which 

has been found to increase soil microbe population diversity (Locke et al., 2008). 

The primary agents degrading glyphosate in soil and water are microorganisms feeding 

on the herbicide (Senseman, 2007). As discussed in Subsection 2.3.3, Microorganisms, 

investigations into the toxicity of glyphosate to microorganisms have produced varied 

results. Earliest studies investigating the impact of glyphosate on soil microorganisms 

did not detect adverse effects under field use conditions, such as on specific, limited 

functional properties of soil bacteria, such as nitrification, or specific species of soil 

bacteria; others found minor effects that could not be separated from changes in habitat, 

and still others reported effects at or near normal glyphosate use rates, but in most cases, 

84
the effects were minor and temporary (Giesy et al., 2000). In more recent experiments, 

glyphosate was applied to two different soil types, and glyphosate stimulated bacterial 

biomass up to 25 fold and utilization of all carbon substrates by culturable bacteria 

increased substantially (Ratcliff et al., 2006). As summarized by Hart (2009) while some 

studies have found effects of glyphosate or the glyphosate resistant crop, many more have 

shown only minor, transient effects. In the case of glyphosate resistant corn, neither crop 

effect nor glyphosate effects resulted in changes to the rhizosphere, denitrifying bacteria,

or fungi (Hart et al., 2009). Later work showed that glyphosate could directly decrease 

rhizosphere populations of three types of soil bacteria around roots of glyphosate resistant 

soybean (Zobiole et al., 2011). Glyphosate applied to soils may reduce soil microbial 

diversity (Barriuso and Mellado, 2012) but less than that of acetochlor (a common, corn 

herbicide) applied pre-emergence; in three year observations and with different soil types 

glyphosate did not impact microbial phyla diversity (Barriuso et al., 2011). Other authors 

show that bacterial biomass can be reduced 7 days after treatment in soybean rhizosphere, 

in soil previously unexposed to glyphosate, but that biodiversity does not change in 

response to glyphosate (Lane et al., 2012). The inconsistent results of these observations 

suggest that any effects of glyphosate may not be easily distinguished from multiple other 

influences, including soil, cultivar type, growth stage of the plant, and experimental 

details (Hart et al., 2009; Farago and Faragova, 2010).

Although mostly anecdotal evidence suggest that use of glyphosate and some glyphosate 

resistant crops may increase frequency, virulence or susceptibility to certain plant 

diseases (as reviewed in Johal and Huber (2009)) substantiation is lacking. APHIS has 

previously examined in detail the potential impacts of glyphosate to microorganisms in 

the cultivation of glyphosate-resistant alfalfa and sugar beets on soil with previously 

cultivated glyphosate resistant crops (USDA-APHIS, 2010; USDA-APHIS, 2011a). 

Based on extensive review of the literature, these EISs conclude glyphosate application 

might favor development of detrimental microbial species (or harm some beneficial 

microbes); however, to date, there is no conclusive evidence linking applications of 

glyphosate to changes in soil microbial communities that have adverse effects on plants 

grown in those soils.

Corn cultivation, including the production of glyphosate-resistant corn and its potential 

impacts to soil microorganisms, is expected to continue under the No Action Alternative. 

The majority of corn grown in the U.S. is herbicide resistant, and glyphosate is the most 

frequently applied herbicide to corn (USDA-ERS, 2011a; USDA-NASS, 2011c). 

Farmers have access to non-glyphosate-resistant corn varieties, and manage their crops 

by implementing practices to control pests and weeds, including the use of glyphosate.

Preferred Alternative: Microorganisms

Approving the petition for nonregulated status of VCO-01981-5 is not expected to result 

in any new impacts to microbial communities. VCO-01981-5expresses the grg23ace5 

epsps gene to make an EPSPS protein (Genective, 2012; USDA-APHIS, 2012a). This 

gene is derived from Arthrobacter globiformis, a common soil-inhabiting bacterium. As 

such, nothing new or unique would be introduced into the environment that may impact 

the microbial community under the Preferred Alternative.

85
VCO-01981-5 has been determined to be agronomically and compositionally similar to 

other nonregulated glyphosate-resistant corn varieties (USDA-APHIS, 2012a). It is not 

expected to change the acreage or area of glyphosate-resistant corn production that 

potentially would expand the use of glyphosate herbicide with potential impacts to soil 

microorganisms. VCO-01981-5 is another glyphosate-resistant corn cultivar likely to 

replace other nonregulated glyphosate-resistant corn varieties. Approximately 73% of 

corn cultivated in the U.S. today is herbicide-resistant and the majority of herbicideresistant corn is glyphosate-resistant , (Duke and Powles, 2009; USDA-NASS, 2012a). 

Because VCO-01981-5 is agronomically similar to other glyphosate-resistant and 

conventional corn, its cultivation would not change the agronomic practices needed for 

its cultivation, such as amount and rate of glyphosate application. 

4.4.4 Biodiversity

No Action Alternative: Biodiversity

All the plants, animals, and microorganisms interacting in an ecosystem contribute to 

biodiversity (Wilson, 1988a) that provides valuable life functions. In agriculture, 

biodiversity contributes to critical functions such as pollination, genetic introgression, 

biological control, nutrient recycling, and other processes the loss of which requires 

costly management (Altieri, 1999). Concerns regarding the potential impacts to 

biodiversity associated with the introduction of GE crops (and crops in general) include 

the loss of diversity, which can occur at the crop, farm, or landscape scale (Visser, 1998; 

Ammann, 2005; Carpenter, 2011) see Subsection 2.3.4, Biodiversity). 

At the crop scale, research suggests that developing GE crops has introduced novel genes 

that has not decreased crop diversity because of widespread use of the traits in multiple 

breeding programs, and the technology enables the introduction of novel genes in crops 

(Ammann, 2005; Carpenter, 2011). Additionally, the concern for the loss of genetic 

variability has led to the establishment of an extensive network of genebanks (van de 

Wouw et al., 2010), including an active collection of more than 14,000 accessions of corn 

at the ARS North Central Regional Plant Introduction Station at Iowa State University, 

Ames, Iowa (USDA-ARS, 2005). These collections are shared with researchers 

worldwide, which helps ensure a continuous reservoir of genetic diversity for future crop 

development. Under this alternative, growers have access to existing nonregulated 

herbicide-resistant and other GE corn varieties, as well as other non-GE corn varieties, 

while VCO-01981-5 corn would remain a regulated article.

At the farm scale, agronomic practices that can impact biodiversity include cropping 

practices (e.g., strip or contour cropping, crop rotation), soil conservation practices that 

maintain grass strips, windbreaks and shelterbelts and the like, tillage, and the application 

of agrochemicals. The rotation of crops and strip contour cropping provide varied habitat 

that can benefit biodiversity. Recently, there has been an increase in corn-to-corn 

rotation given the profitability of corn production (USDA-ERS, 2011b). As discussed in 

Subsection 2.1.2., Agronomic Practices, continuous corn production must be highly 

managed to maintain productivity, which can be less beneficial to biodiversity; however, 

the practice does accumulate more crop residue that benefits some species. The 

establishment of soil conserving grass and other vegetative borders stabilize soil that 

86
maintains additional wildlife habitat, and improves the quality of existing habitat (such as 

surface water quality) that contributes to biodiversity. Allowing unproductive field edges 

to become managed wildlife habitat promotes diversity in both plants and animal species 

(Sharpe, 2010). 

Modern agricultural practices may simplify the agricultural landscape, with the result that 

beneficial arthropods may be adversely affected (Landis et al., 2005). On the other hand, 

the adoption of conservation tillage has been noted to increase resource diversity within 

agricultural settings, including refuge habitat, which can then support a larger community 

of beneficial organisms (Landis et al., 2005). 

Herbicides are used to control plants in areas where humans do not want them. As 

described in Subsection 2.1.2, Agronomic Practices, weeds compete with crops for light 

and nutrients, reducing yields. Glyphosate effectively kills grass and broadleaf plants 

when applied at the recommended rates. At the farm scale, herbicide use in agricultural 

fields may impact biodiversity by decreasing weed quantities or causing a shift in weed 

species present in the field, which may affect those insects, birds, and mammals that use 

these weeds. The quantity and type of herbicide use associated with herbicide-resistant 

corn crops, however, is dependent on many variables, including cropping systems, type 

and abundance of weeds, production practices, and individual grower decisions. See 

Subsection 2.1.2, Agronomic Practices, for a detailed discussion of pesticide use in corn 

production. The effects of glyphosate on plants and animals are presented in the 

following discussion of landscape-scale biodiversity. 

Use of herbicide-resistant crops such as corn has been linked to increased rates of 

conservation tillage in U.S. crop production (Givens et al., 2009). This promotes 

biodiversity by allowing the establishment of other plants between crop rows and the 

accumulation of more plant residue that creates more soil organic matter, food, and cover 

for wildlife. In a review of literature that assessed the impacts of GE crops on 

biodiversity, (Carpenter, 2011) found that, for the most part, impacts to biodiversity have 

been positive due to increased yields, decreased usage of insecticides, use of more 

environmentally friendly herbicides, and facilitation of conservation tillage. In 2010, 

62% of planted corn acreage in 19 surveyed states was dedicated to no-till or minimum 

till systems (USDA-NASS, 2011c). As described in Subsection 2.3.2, Plant 

Communities, the increasing incidence of herbicide-resistant weeds is also causing 

farmers to turn to more diversified weed management strategies, including increased 

tillage that potentially reduces biodiversity. 

Crop production in general impacts biodiversity at the landscape scale by potentially 

converting natural lands that have greater animal and plant species diversity to more 

monocultural landscapes. Corn is the largest crop grown in the U.S. in terms of acreage 

planted and geographic area of production with over 96 million planted acres in 2012 

(USDA-NASS, 2012a). USDA projections to 2020 indicate the acreage devoted to corn 

production in the U.S. will remain relatively stable at this level (USDA-OCE, 2011a). 

The greatest direct impact of agriculture on biodiversity on the landscape scale results 

from the loss of natural habitats caused by the conversion of natural ecosystems into 

agricultural land (Ammann, 2005). A literature review by (Carpenter, 2011)revealed that 

increases in crop yields, such as may be attained with GE crops (including herbicide87
resistant corn) have the potential to reduce impacts to biodiversity by allowing less land 

to be converted to agriculture than would otherwise be necessary; however, substantial 

gains in yields have generally not been obtained by herbicide-resistant cultivars unless 

higher yielding cultivars are modified with an herbicide-resistant trait (USDA-NRCS, 

2010). 

Adoption of GE technology has the potential to impact diversity at the farm scale by 

affecting a farm’s biota, including birds, wildlife, invertebrates, soil microorganisms, and 

weed populations. For example, an increase in adoption of conservation tillage practices 

is associated with the use of GE herbicide-resistant crops (Givens et al., 2009). Less 

tillage provides more wildlife habitat by allowing other plants to establish between crop 

rows. Conservation tillage leaves a higher rate of plant residue and increases soil organic 

matter (Hussain et al., 1999; Towery and Werblow, 2010b) which benefit soil biota by 

providing additional food sources and energy (USDA-NRCS, 1996). In addition, 

invertebrates that feed on plant detritus and their predators as well as the birds and other 

wildlife that feed on them, may benefit from increases in conservation tillage practices 

(Towery and Werblow, 2010b) (Carpenter, 2011). Ground-nesting and seed-eating birds, 

in particular, have been found to benefit from greater food and cover associated with 

conservation tillage (SOWAP, 2007).

Herbicide use in agricultural fields may impact biodiversity by decreasing weed 

quantities or causing a shift in weed species present in the field, which may affect those 

insects, birds, and mammals that utilize these weeds. The quantity and type of herbicide 

use associated with GE crops, however, is dependent on many variables, including 

cropping systems, type and abundance of weeds, production practices, and individual

grower decisions. 

As with farm-scale diversity, use of herbicides at the landscape scale also has the 

potential to impact biodiversity (Chamberlain et al., 2007). Area-wide herbicide 

application may increase certain populations of invertebrates and wildlife that benefit 

from conservation tillage, whereas species that are dependent on the targeted weeds may 

be negatively impacted. 

Further, potential impacts to landscape-scale diversity can be related to the effects of 

herbicides on non-target animal and plant species. Assessments of the toxicity of 

glyphosate to animal species indicate a minimal risk to animals, but it may cause adverse 

effects to plants composing the animals’ habitat. As discussed in Subsection 2.3.1, 

Animal Communities, glyphosate was found by the EPA to be no more than slightly toxic 

to birds, moderately toxic to practically nontoxic to fish, and practically nontoxic to 

aquatic invertebrates and honeybees (US-EPA, 1993a). Spraying herbicides onto crops 

has the potential for inadvertent contact and damage to non-target plants; the EPA is 

currently evaluating additional labeling requirements concerning BMPs for controlling 

pesticide spray drift (see Subsection 2.3.2, Plants Communities). While herbicide use 

potentially affects biodiversity, the application of pesticides in accordance with registered 

uses and label instructions, and careful management of chemical spray drift, minimizes 

the potential impacts from their use. 

Preferred Alternative: Biodiversity

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Under the Preferred Alternative, VCO-01981-5 corn would be extended a nonregulated 

determination, providing growers an additional glyphosate-resistant corn variety. VCO01981-5 corn is functionally the same other GE and non-GE corn with regard to 

agronomic characteristics, growth, reproductive habit, utilization of resources, and 

production practices (Stine, 2011; USDA-APHIS, 2011b; Genective, 2012; USDAAPHIS, 2012a). The preferred alternative is unlikely to have any direct effects on nontarget organisms associated with exposure to its gene products and the modified EPSPS 

protein expressed by the cultivar. The genetic material in and proteins produced by 

VCO-01981-5 is similar to those of the nonregulated corn varieties in commercial 

production (USDA-APHIS, 2012a). 

Area-wide herbicide application may negatively impact species that are dependent on the 

targeted weeds, reducing diversity. As stated above, the majority of corn cultivated in the 

U.S. is treated with herbicides and glyphosate is the most-applied herbicide to corn 

(USDA-NASS, 2011e). Potential impacts to landscape-scale diversity can be related to 

the effects of herbicides on non-target animal and plant species. Assessments of the 

toxicity of glyphosate to animal species indicate a minimal risk to animals, but it is toxic 

to targeted plants and may affect non-targeted plants and animals through spray drift, 

volatilization (i.e., evaporation) and runoff. Inadvertent exposure may cause adverse 

effects to plants composing animal habitats that could lead to a decrease in biodiversity. 

As discussed in Subsection 2.3.1, Animal Communities, glyphosate was found by the 

EPA to be no more than slightly toxic to birds, moderately toxic to practically nontoxic to 

fish, and practically nontoxic to aquatic invertebrates and honeybees (US-EPA, 1993b). 

The EPA is currently evaluating additional labeling requirements concerning BMPs for 

controlling pesticide spray drift (see Subsection 2.3.2, Plant Communities). While 

herbicide use potentially affects biodiversity, the application of pesticides in accordance 

with registered uses and label instructions, and careful management of chemical spray 

drift, minimizes the potential impacts from their use. 

In 2009, the EPA initiated reregistration of glyphosate and has identified additional data 

needs. Part of the risk assessment will include an acute avian oral toxicity study for 

passerine species. Additionally, some inert ingredients used as surfactants are more toxic 

than glyphosate to aquatic organisms, and will also be evaluated for acute toxicity to 

estuarine and marine mollusk, invertebrates, and fish (US-EPA, 2009g). 

Because VCO-01981-5 corn is another glyphosate-resistant cultivar option, it would 

likely replace other glyphosate-resistant corn varieties without expanding the acreage or 

area of corn production that could impact farm and landscape-scale biodiversity. 

Approximately 73% of corn planted in the U.S. in 2012 was herbicide resistant, and the 

majority of herbicide-resistant corn is glyphosate-resistant (Duke and Powles, 2009; 

USDA-NASS, 2012a). Also, based on its similarity to other corn as described above, 

VCO-01981-5 corn would not result in changes to agronomic practices such as crop 

rotation, soil conservation, tillage, weed management, or pesticide use that potentially 

impact farm- or landscape-scale biodiversity. 

Based on the above information, APHIS has concluded the Preferred Alternative would 

not have impacts to crop-, farm-, or landscape-scale biodiversity any different than other 

currently available glyphosate-resistant corn cultivars. As such, the effects on

biodiversity under this alternative would be the same as the No Action Alternative.

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4.5 Public Health 

4.5.1 Consumer Health

No action alternative

As discussed in Subsection 2.1.1, Acreage and Area of Corn Production, 88% of corn 

grown in the U.S. in 2012 was GE (USDA-NASS, 2012a). The majority of GE 

herbicide-resistant corn grown in the U.S. is glyphosate resistant (Duke and Powles, 

2009). Authors have suggested that the human health concerns associated with GE crops 

include the potential toxicity of the introduced genes and their products, the expression of 

new antigenic proteins, and/or altered levels of existing allergens (Malarkey, 2003; Dona

and Arvanitoyannis, 2009). Previous studies of the EPSPS protein, which confers 

glyphosate resistance, found that the EPSPS protein expressed through genetic 

engineering poses no potential for toxicity or allergenicity (Harrison et al., 1996; Ridley 

et al., 2002; Batista et al., 2005; Hoff et al., 2007; Herouet-Guicheney et al., 2009). 

Some people are allergic to corn, but corn is not included in the FALCPA as one of the 

most common food allergens (see Subsection 2.4.1, Consumer Health). An additional 

concern with GE food crops is the potential for increased levels of anti-nutrients (Dona 

and Arvanitoyannis, 2009). As discussed in Subsection 2.4.1, Consumer Health, there 

are several naturally occurring anti-nutrients found in corn, including phytic acid, 

DIMBOA, raffinose, and low levels of trypsin and chymotrypsin inhibitors (OECD, 

2002a). 

It should be noted also that a previous biotechnology consultation of the EPSPS protein 

that confers glyphosate resistance was completed by the FDA on the GA21 corn variety 

(BNF No. 000051) on February 10, 1998 (US-FDA, 1998). Pending results of the final 

biotechnology consultation with the FDA, potential impacts to food safety from 

production of VCO-01981-5 corn under the Preferred Alternative would be similar to 

those of other glyphosate-resistant corn cultivars as described for the No Action 

Alternative. 

Under the No Action Alternative agricultural production of nonregulated GE and non-GE 

corn employ EPA-registered pesticides for insect and plant pest management, including 

glyphosate. Glyphosate may also be applied to regulated VCO-01981-5 corn cultivated 

under confined conditions. The environmental risks of pesticide use are assessed by the 

EPA in the pesticide registration process and a pesticide is regularly reevaluated by the 

EPA to maintain its registered status under FIFRA. The human health effects from 

exposure to glyphosate have been evaluated by the EPA. The 1993 glyphosate RED 

presents the data used by the EPA for chemical reregistration (US-EPA, 1993b). As 

previously discussed in Subsection 2.4.1, Consumer Health, the review for reregistration 

began in July 2009; the EPA is currently conducting a comprehensive human health 

assessment for all uses of glyphosate and its salts (US-EPA, 2009c). The glyphosate 

RED presents the EPA’s analysis of the toxicity, carcinogenicity, and developmental 

toxicity of this herbicide. Glyphosate is classified as having low toxicity via the oral, 

dermal, and inhalation routes and is not classified as a carcinogen or teratogen (US-EPA,

2009c), (US-EPA, 2009d). Moreover, neurotoxicity has not been reported in any acute, 

subchronic, chronic, developmental, or reproductive studies, although additional studies 

90
will occur as part of the current review process (US-EPA, 2009d). Based on additional 

toxicity tests, the EPA determined the main glyphosate metabolite AMPA does not 

require regulation (US-EPA, 2009d). 

As presented in Subsection 2.4.1, Consumer Health, pesticide tolerance levels for 

glyphosate on field corn such as VCO-01981-5 corn have been established (US-EPA, 

2011c). Tolerances are the limits on the amount of pesticide that may remain on or in 

foods marketed in the U.S., that are established for every pesticide based on its potential 

risks to human health. The maximum tolerance level for glyphosate in field corn is 5.0 

ppm for grain (40 CFR §180.364). 

VCO-01981-5 corn is a GE variety of corn that has been modified to add resistance to the 

herbicide glyphosate (Genective, 2012). This resistance was conferred using a sequence 

of DNA derived from the soil bacterium, Arthrobacter globiformis. The grg23 epsps gene 

was modified for enhanced temperature stability as the grg23ace5 epsps gene and which 

was subsequently reintroduced back into the corn DNA. The EPSPS ACE5 enzyme 

product is similar to that produced by the GE GA21 corn that was previously determined 

as nonregulated (USDA-APHIS, 2012b). In addition, except for the CaMV 35S 

terminator, all sequences including promoter, intron, and chloroplast transit peptide 

inserted into event VCO-01981-5 corn are either derived from the corn genome or from 

other non pest sequences. As discussed above, studies have found that the EPSPS protein 

expressed in glyphosate-resistant crops is safe and that the VCO-01981-5 corn is 

compositionally similar to, and is as safe and nutritional as, the same non-GE crops 

(Ridley et al., 2002; Batista et al., 2005; Genective, 2012). Composition of GE EPSPS 

containing crops is not altered by herbicide treatment (Taylor et al., 1999), nor would 

there be expectation that it might be so altered. As discussed in Subsection 2.4.1, 

Consumer Health, Genective (through a predecessor organization, Athenix Corporation) 

initiated a consultation with the FDA by submitting an early food safety evaluation of the 

ACE5 epsps protein expressed in VCO-01981-5 corn (NPC 000012: Agency Response 

Letter) on 10/07/2009 (early food safety evaluation of new non-pesticidal proteins). FDA 

completed its evaluation with no further questions on 10/15/2010 (US-FDA, 2010). 

Because VC-01981-5 corn is within the scope of the FDA policy statement concerning 

regulation of products derived from new plant varieties, including those produced 

through genetic engineering, Genective initiated the consultation process with FDA for 

the commercial distribution of event VCO-01981-5. Genective submitted a safety and 

nutritional assessment of food and feed derived from VCO-01981-5 corn to the FDA on 

March 5, 2012 (BNF-000137). FDA is presently evaluating the submission.

In Genective’s study of anti-nutrients, raffinose, phytic acid and trypsin inhibitors were 

not significantly different from non-GE controls or reference hybrids (Genective, 2012). 

In Genective’s study of 51 nutrients and anti-nutrients in VCO-01981-5 corn, a few were 

significantly different from the non-GE control, but all were found to be within the 

ranges expected of commercial corn (Genective, 2012). Similarly, in a study of the CP4 

EPSPS protein conferring glyphosate resistance in other corn hybrids, Ridley (2002)

found the genetic modification to confer glyphosate resistance did not significantly 

change any of the 51 biologically and nutritionally important components evaluated. 

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Under the Preferred Alternative, pesticide tolerance levels for glyphosate on field corn 

would not change. Tolerances are the limits on the amount of pesticide that may remain 

on or in foods marketed in the U.S. established for every pesticide based on its potential 

risks to human health. As specified in 40 CFR §180.364, the glyphosate tolerance level 

for field corn grain is 5.0 ppm. As discussed in Subsection 4.2.2, Agronomic Practices, 

the use of glyphosate in corn production would be unaffected by the nonregulated status 

of VCO-01981-5 corn. The application rate of glyphosate in corn would not likely 

change as a result of the Preferred Alternative since VCO-01981-5 corn is expected to 

replace other glyphosate-resistant corn cultivars (see Subsection 4.2.1, Acreage and Area 

of Corn Production), is similar to other nonregulated glyphosate-resistant cultivars in its 

cultural requirements, and no change to the registered use of glyphosate is proposed. 

4.5.2 Worker Safety

No action alternative

It has been suggested that the importance producers place on worker safety, perceived 

increased simplicity and flexibility of farm management, and decreased risk in production 

can be partially attributed to the high rate of adoption of GE crops (NRC, 2004). 

There are no data indicating that workers exposed to herbicide-resistant corn (raw or 

byproducts), such as that which might occur during production, transportation, and 

milling, have experienced adverse reactions. While a small portion of the population 

does suffer from corn allergies, the EPSPS protein that confers glyphosate resistance in 

VCO-01981-5 corn has been determined not to be an allergen (see Subsection 2.4.1, 

Human Health). 

Agricultural workers that routinely handle glyphosate (mixers, loaders, and applicators) 

may be exposed during and after use. Due to glyphosate’s low acute toxicity and lack of 

carcinogenicity and other toxicological concerns, occupational exposure data is not 

required for reregistration (US-EPA, 1993a); however, the glyphosate RED does classify 

some end-use glyphosate products as eye and skin irritants and recommends PPE be worn 

by mixers, loaders, and applicators (US-EPA, 1993b). Additionally, due to the potential 

for skin and eye irritation, the EPA has set the restricted entry interval for glyphosate to 

12 hours after products have been applied. Due to the expected short-term dermal and 

inhalation exposures of occupational handlers and growers, no endpoints were identified 

by the HED, and as such, no occupational handler or occupational post-application 

assessments are required for reregistration (US-EPA, 2009d). Current EPA-approved 

labels for glyphosate include precautions and measures to protect human health. When 

used consistent with the label, pesticides present minimal risk to human health and safety. 

Preferred Alternative

Potential risks to occupational handlers and growers during glyphosate application to 

VCO-01981-5 corn would be the same as those presented under the No Action 

Alternative. There would be no increased risk to workers’ health or safety from exposure 

to VCO-01981-5 corn or byproducts during typical agricultural-related activities. 

Moreover, as discussed above, the application rate of glyphosate would not likely change 

and no change to the registered use of glyphosate is proposed under the Preferred 

92
Alternative. Potential risks to farm workers from the use of glyphosate would be the 

same as the No Action Alternative.

4.6 Animal Feed

No Action Alternative: Animal Feed

As described in Subsection 2.5, Animal Feed, most of the corn produced in the U.S. is for 

animal feed that is consumed primarily by cattle, poultry, and swine , (NCGA, 2011; 

USDA-ERS, 2011b). Corn comprises over 95% of the total feed grain produced in the 

U.S. (USDA-ERS, 2011b). In 2012, corn was grown on over 96 million acres (USDANASS, 2012a) and measurably produced in all states but Alaska (USDA-NASS, 2009). 

As discussed in Subsection 2.5, Animal Feed, 45% of the corn consumed in the U.S. in 

2010 was used for animal feed (Fig. 6 (Schnepf, 2011)). In 2012, 73% of the corn 

produced in the U.S. was genetically engineered to be resistant to herbicides, consisting 

primarily of glyphosate-resistant cultivars (Duke and Powles, 2009); (USDA-NASS, 

2012a). The amount of corn that is used for feed is dependent on a number of factors 

such as the number of animals that are fed corn, its supply and price, the amount of 

supplemental ingredients added, and the supply and price of competing ingredients 

(USDA-ERS, 2011b). Under the No Action Alternative, corn forage, silage, grain, and 

refined corn feed products from currently cultivated GE herbicide-resistant and 

conventional corn varieties are utilized by livestock producers. 

It is the responsibility of feed manufacturers to ensure that the products they market are 

safe and properly labeled and feed derived from GE corn must comply with all applicable 

legal and regulatory requirements, which in turn protect human health (see Subsection 

2.5, Animal Feed). All applicants who wish to commercialize a GE variety that will be 

included in the food supply complete a consultation with the FDA to identify and discuss 

relevant safety, nutritional, or other regulatory issues regarding the bioengineered food 

and submits a summary of its scientific and regulatory assessment of the food to FDA

(US-FDA, 2012). The FDA evaluates the submission and responds to the developer by 

letter. 

Genective (through a predecessor organization, Athenix Corporation) initiated a 

consultation with the FDA by submitting an early food safety evaluation of the ACE5 

epsps protein expressed in VCO-01981-5 corn (NPC 000012: Agency Response Letter) 

on 10/07/2009. FDA completed its evaluation with no further questions on 10/15/2010 

(US-FDA, 2010). Because VCO-01981-5 corn is within the scope of the FDA policy 

statement concerning regulation of products derived from new plant varieties, including 

those produced through genetic engineering, Genective SA initiated the consultation 

process with FDA for the commercial distribution of event VCO-01981-5 corn. 

Genective submitted a safety and nutritional assessment of food and feed derived from 

VCO-01981-5 corn to the FDA on March 5, 2012 (BNF-000137). FDA is presently 

evaluating the submission.

A biotechnology consultation for a similar EPSPS protein was completed by the FDA on 

the GA21 corn variety (BNF No. 000051) on February 10, 1998 (US-FDA, 1998). No 

food safety issues were found by the FDA in their review of Monsanto’s safety and 

nutritional assessment of GA21 corn and the modified EPSPS protein.

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The preferred alternative is not likely to result in any additional use of glyphosate, since 

this corn event will likely only replace other similar corn. This herbicide currently has 

established tolerances for residues, including established residue concentrations for 

glyphosate in field corn for forage, grain, and stover. The EPA establishes tolerances to 

regulate the amount of pesticide residues that can remain on food or feed commodities as 

the result of pesticide applications(US-EPA, 2011c). The tolerance level is the maximum 

residue level of a pesticide that can legally be present in food or feed, and if pesticide 

residues are found to exceed the tolerance value, the food is considered adulterated and 

may be seized.

Agricultural production of existing commercially available glyphosate-resistant corn 

varieties uses EPA-registered pesticides, including glyphosate. The interval between post 

emergence corn application of glyphosate and when the grain may be subsequently 

harvested is seven days (Monsanto, 2010a). The interval between post-harvest 

application of glyphosate and when the corn vegetation may be used as feed varies with 

product labels, for example the Roundup Power Max® interval is seven days (Monsanto, 

2010a) while the Glyphosate 41 Plus ® interval for any stage is 50 days (CropSmart, 

2009). Tolerances are the limits on the amount of pesticide that may remain on or in 

foods marketed in the U.S. that are established for every pesticide based on its potential 

risks to human health. The maximum tolerance level for glyphosate in field corn is 5.0 

ppm for grain and is 6.0 ppm for forage (40 CFR §180.364). 

Preferred Alternative: Animal Feed

As described for the No Action Alternative, the amount of corn that is used for feed 

is dependent on several factors, including price, supply, and the number of animals 

that are fed corn (USDA-ERS, 2011b). Because herbicide-resistant corn is the 

majority of corn produced in the U.S. today, and most of that is glyphosate resistant 

(USDA-ERS, 2011a), VCO-01981-5 corn would likely replace other glyphosateresistant cultivars without impacting the supply of corn for animal feed.

Genective has submitted compositional and nutritional characteristics of VCO01981-5 corn grain and forage to APHIS (Genective, 2012). Samples of VCO01981-5 corn and its comparators that were sprayed with glyphosate were collected 

from six different field trial locations (four for grain samples and two for forage 

samples) and analyzed for comparable nutritional components in accordance with 

Organisation for Economic Co-operation and Development (OECD) guidelines 

(OECD, 2002a). Tested parameters include proximates (protein, fat, carbohydrates, 

fiber, ash, calcium phosphorus and moisture), minerals, amino acids, fatty acids, 

vitamins, isoflavones, and antinutrients and secondary metabolites (i.e., ferulic acid, 

phytic acid, trypsin inhibitor, raffinose, inositol, and ρ-coumaric acid) (Genective, 

2012). VCO-01981-5 corn is similar in compositional and nutritional characteristics 

to other varieties of GE and non-GE corn (Genective, 2012; USDA-APHIS, 2012a).

A biotechnology consultation of the EPSPS protein that confers glyphosate resistance 

in the VCO-01981-5 corn variety has been completed (See Subsection 4.5, Public 

Health). Genective submitted a safety and nutritional assessment of food and feed 

derived from VCO-01981-5 corn to the FDA in March 2012 in support of the 

94
consultation process with the FDA for the commercial distribution of VCO-01981-5 

corn (Genective, 2012). The on Animal health of the Preferred Alternative would 

change when compared the No Action Alternative.

As discussed above, label restrictions for glyphosate’s application to corn prohibits 

harvesting the grain prior to seven days after application and the interval for 

harvesting or feeding the vegetation is dependent on the individual glyphosate 

product label. As discussed in Subsection 4.2.2, Agronomic Practices, the registered 

uses of glyphosate on VCO-01981-5 corn or other corn would not change as a result 

of the Preferred Alternative, nor would herbicide label restrictions for feeding corn 

after treatment. Similarly, no change to the EPA-established tolerances of 

glyphosate in treated corn intended for forage or grain harvested for animal feed that 

could impact animal health would be required for of VCO-01981-5 corn. 

4.7 Socioeconomic Impacts

4.7.1 Domestic Economic Environment

No Action Alternative: Domestic Economic Environment

Under the No Action Alternative, farmers and other parties who are involved in 

production, handling, processing, or consumption of corn have access to existing 

nonregulated herbicide-resistant, conventional, GE, and organic corn varieties. In 

terms of value, corn is the primary U.S. crop exceeding $76.4 billion in 2011

(USDA-NASS, 2012c), and it is expected corn would retain current planted acreage 

levels at least until 2020 (USDA-OCE, 2011a). Almost all of the U.S. corn supply 

(91.4% in 2011/12) comes from new annual domestic production (USDA-ERS, 

2012b). In the 2011/12 marketing year, less than half (41.4%) of domestic corn 

usage was for feed, while approximately 45.6% of domestic use was for the 

production of ethanol (USDA-ERS, 2012b). Total operating costs for U.S. corn 

production were $332.34 per planted acre (USDA-ERS, 2012c). Corn is widely 

produced in the U.S. (see Subsection 2.1.1, Acreage and Area of Corn Production, 

Figure 1). The most productive and profitable regions are the Heartland and 

Northern Crescent (USDA-ERS, 2012c). As discussed in Subsections 2.1.3, Organic 

Corn Production, and 2.6.1, Domestic Economic Environment, organic corn 

production is a small portion of the U.S. corn market. The value of corn produced 

for grain or seed from organic-certified farms in the U.S. in 2008 was nearly $111.5

million (USDA-NASS, 2010a).

Most corn planted in the U.S. today is stacked GE varieties with both herbicide and 

insect resistance (USDA-ERS, 2011a). The widespread adoption of herbicideresistant corn has been attributed to the cost savings for production, among other 

non-monetary benefits as described in Subsection 2.1.2, Agronomic Practices (Duke 

and Powles, 2009; NRC, 2010a; Green and Owen, 2011). Of the herbicide-resistant 

corn varieties on the market today, growers may choose from glyphosate, 

glufosinate, glyphosate stacked with imidazolinone resistance traits (USDA-APHIS, 

2012b).

GE technology is patented and GE seeds are proprietary in the U.S.(NRC, 2010a). 

The costs for GE seed are higher than that for conventional seed, as GE seed includes 

95
technology fees (NRC, 2010a). The higher seed costs, however, may be offset by 

other premiums offered by companies, such as discounts for herbicides to use on the 

resistant crop, and reductions in crop insurance (NRC, 2010a). As discussed in 

Subsection 2.6.1, Domestic Economic Environment, estimates of the economic 

benefits of herbicide-resistant crops to farmers are limited (NRC, 2010a), and studies 

that have been conducted have had mixed results. Overall, these studies indicate in 

the early years of the adoption, GE cultivars exerted downward pressure on crop 

prices while the earnings of adopting farmers increased, and barriers to market access 

for GE crops reduced grower income (NRC, 2010a). 

Farmers have recently broadened weed management to treat herbicide-resistant 

weeds which may be impacting yields, leading to more variety in herbicide 

application and increased tillage, potentially incurring higher production costs. 

Weirich (2011b), however, investigated the economic effects of alternative 

glyphosate weed resistance management programs, finding that although they 

increased cost substantially, higher yields offset these costs such that no statistically 

significant decrease in net returns occurred. Their study suggests growers may be 

able to effectively respond to glyphosate resistance using weed BMPs without 

substantially affecting their returns.

As indicated in Subsection 2.1.1, Acreage and Area of Corn Production, the trend 

over the last several years in the U.S. has been to stack herbicide resistance with 

primarily insect-resistant traits. Developers have recently sought approvals for corn 

varieties that have multiple herbicide and insect resistance, as well as other value 

added traits ((USDA-APHIS, 2012b). Herbicide-resistant-only corn has consistently 

comprised approximately 22 to 23% of planted corn in the U.S. since 2007 (USDAERS, 2011a). Only two companies hold the licenses for the majority of herbicideresistant corn in the U.S.: Monsanto patented glyphosate-resistant corn technology 

and offers varieties in their Roundup Ready® corn lines, and Bayer CropScience 

licenses glufosinate-resistant corn in their LibertyLink® corn lines. Glufosinateresistant corn has been commercially available even longer than glyphosate-resistant 

corn, but has not been as successful, thought to be due to the higher cost of 

glufosinate and its more restrictive application timings to smaller plants to increase 

its efficacy (Owen, 1999; Green and Owen, 2011). Growers have perceived a lack of 

competition in the U.S. herbicide- and insect-resistant seed corn market based on 

substantial increases in the price of GE seed in the last several years (Neuman, 2010). 

This observation may correlate with the ongoing concentration of the U.S. seed 

market since passage of the Plant Variety Protection Act in the 1970s established 

proprietary rights for certain plant varieties (Fernandez-Cornejo, 2004). In 2011, 

corn seed comprised approximately 25% of total per acre operating costs for farmers 

(USDA-ERS, 2012c). Industry has responded that the quality of seed offered has 

improved, and new GE traits have been added that lower costs associated with 

improved insect and weed control, among other production costs (Neuman, 2010). 

Preferred Alternative: Domestic Economic Environment

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Availability of VCO-01981-5 corn could potentially impact agronomic inputs and 

associated on-farm costs as well as the U.S. domestic corn market. Under the Preferred 

Alternative, VCO-01981-5 corn would be extended nonregulated status. Farmers and 

other parties who are involved in the production, handling, processing, or consumption of 

corn would have access to VCO-01981-5 corn. 

VCO-01981-5 corn has been determined to be similar in its composition, growth habits, 

and cultural requirements to its comparators and other nonregulated glyphosate-resistant 

corn (Genective, 2012; USDA-APHIS, 2012a). Since this new cultivar is glyphosateresistant and would directly compete with other glyphosate-resistant corn varieties, the 

market share of other glyphosate-resistant corn may diminish. As discussed above, 

herbicide-resistant corn dominates U.S. corn production, either as herbicide-resistantonly varieties or stacked with other traits; therefore, VCO-01981-5 corn would likely 

replace other glyphosate-resistant corn cultivars without impacting corn acreage or 

production area that may affect domestic markets. As another glyphosate-resistant corn 

cultivar in the market, nonregulated VCO-01981-5 corn may increase competition, the 

extent of which is dependent upon growers finding value in it. As discussed above, 

growers may currently choose from glyphosate, glufosinate, and glyphosate stacked with 

imidazolinone resistance traits. It is reasonable to assume VCO-01981-5 corn may be 

stacked with other traits, similar to other glyphosate-resistant corn cultivars. APHIS 

assumes that the technology fees for VCO-01981-5 corn seed would be consistent with 

those charged by developers for other GE crop varieties already in the marketplace. 

APHIS has no control over the establishment of these technology fees, and each grower 

must make an independent determination as to whether the benefits of the GE variety 

would offset those technology access costs.

Since VCO-01981-5 corn is similar in growth habits and cultural requirements to other 

nonregulated herbicide-resistant, GE and non-GE corn varieties (Genective, 2012), no 

changes to agronomic inputs or practices would be anticipated that may impact on-farm 

costs for corn producers or the U.S. domestic corn market. As discussed above, farmers 

are broadening their weed control tactics in response to developing herbicide-resistant 

weeds, including glyphosate-resistant weeds (see Subsection 2.3.2, Plant Communities, 

Table 2.10). These BMPs increase costs of production; however, the costs appear to be 

offset by increases in yields, having little negative impact to net returns (Weirich et al., 

2011a). As discussed above, VCO-01981-5 corn is similar to and expected to replace 

other glyphosate-resistant cultivars, and would, therefore, have no effect on the 

development of herbicide-resistant weeds or weed management practices different than 

those identified for the No Action Alternative.

Certified organic corn cannot include GE cultivars in the U.S. (USDA-AMS, 2010). As 

discussed under the No Action Alternative, the organic corn market serves a smaller 

consumer niche for corn in the U.S. corn market. Because VCO-01981-5 corn’s 

similarity to other corn in its reproductive characteristics, it is expected U.S. organic 

producers would continue to meet organic certification requirements as outlined in 

Subsection 2.1.3, Organic Corn Production, by implementing standard practices to 

preserve the identity of their organic corn crop. 

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Based upon the above, APHIS has found that the preferred alternative would have 

potential domestic economic impacts no different than those currently observed under the 

No Action Alternative for other glyphosate-resistant corn varieties. 

4.7.2 Trade Economic Environment

No Action Alternative: Trade Economic Environment

Under the No Action Alternative, VCO-01981-5 corn would continue to be a regulated 

article. Farmers, processors, and consumers in the U.S. would not have access to VCO01981-5 corn, but do have access to existing nonregulated herbicide-resistant and non-GE 

corn varieties, as do the major U.S. corn export competitors. 

The U.S. is the leading exporter of corn in the world market (see Subsection 2.6.2, Trade 

Economic Environment), while other important exporters are Argentina, Brazil, and 

Ukraine. In the 2011/2012 marketing year (August to September), the U.S. exported 

approximately 37% of the world’s corn while Japan, Mexico, and South Korea were the 

major importers (USDA-FAS, 2012). In 2011, corn exports were worth approximately 

$13.7 billion (USDA-ERS, 2012d). U.S. corn supply, the value of the U.S. dollar and 

other currencies, oil prices, U.S. and international agricultural policy, the U.S. and 

international biofuels sector, livestock and meat trade, prices, and population growth are 

all factors affecting where and how much of U.S. corn is exported (USDA-ERS, 2011c); 

(USDA-OCE, 2011a). In addition, consumer perception of GE crop production and 

products derived from GE crops may present barriers to trade. Over the past decade, U.S. 

corn export share has eroded as exports have remained relatively stable while global 

exports have increased by almost 20% (See Subsection 2.6.2, Trade Economic 

Environment). U.S. share of world corn production has declined as well, even as total 

world production increased. This is attributed to greater domestic use of U.S. corn, 

smaller corn crops, and increased competition from other major corn exporters such as 

Argentina, Brazil, and Ukraine (USDA-FAS, 2012), countries with increasing GE 

herbicide- and insect-resistant corn production acreage (Brookes and Barfoot, 2010). 

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Figure 2: US and world corn exports for marketing years 2000/2001 to 2010/2011. 

Source: (USDA-FAS, 2004; USDA-FAS, 2005; USDA-FAS, 2006; USDA-FAS, 2007; 

USDA-FAS, 2008a; USDA-FAS, 2009; USDA-FAS, 2010a; USDA-FAS, 2011a)

Market years extend from September to August. Major world exporters include 

Argentina, Brazil, Canada, China, EU-27, India, Paraguay, Romania, Serbia, South 

Africa, Thailand, Ukraine and Zambia as well as other smaller exporting countries. Note 

that the US percentage of corn exports in relation to overall world exports declined at the 

end of the last decade.

0

20

40

60

80

100

120

Million Metric Tons

Marketing Year (Sept.-Aug.)

Rest of

World

United States

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Figure 3: US and major exporters of corn for marketing years 1960/1961-2011/2012. 

Source: (Capehart, 2013). 

Note the increase in exports of corn in countries other than the top three, and the decline 

in US exports in most recent years.

Farmers in the U.S. and abroad have begun to utilize BMPs to control glyphosate or other 

herbicide-resistant weeds, but these BMPs have not necessarily increased costs (Weirich 

et al., 2011a) such that the competitiveness of U.S. corn and trade economic environment 

would be affected. Increasing herbicide weed resistance is also occurring in other 

countries producing herbicide-resistant crops, including U.S. corn export competitors (for 

example, Argentina and Brazil (Heap, 2012) that would likely incur increases in 

production cost to mitigate the incidence of glyphosate-resistant weeds, similar to the 

U.S. experience.

As of publication of this EA, Genective is likely to submit applications for regulatory 

approval to export VCO-01981-5 to Canada, the EU and to Japan for cultivation and use 

as food and feed. Canada is not a major corn export competitor of the U.S.; in the 

2011/2012 market year, Canadian corn exports equalled only about 1.3% of the U.S. corn 

exports that year (USDA-FAS, 2012).

Preferred Alternative: Trade Economic Environment

Under the Preferred Alternative, VCO-01981-5 would be determined nonregulated and 

available to U.S. growers. Availability of VCO-01981-5 could potentially impact the 

corn seed, feed, and food trade. VCO-01981-5 is compositionally and agronomically 

similar to its comparators and other nonregulated glyphosate-resistant corn (Genective, 

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2012; USDA-APHIS, 2012a). As such, it is not expected to affect the seed, feed, or food 

trade any differently than other nonregulated glyphosate-resistant corn varieties (see 

Subsections 4.7.1, Domestic Economic Environment). As another glyphosate-resistant 

corn cultivar, VCO-01981-5 is expected to replace other glyphosate-resistant cultivars to 

the extent growers find value. Approval of the request to determine nonregulated status

to VCO-01981-5 would, therefore, not likely increase the U.S. supply of corn that may 

affect trade. As discussed above, other countries are increasing their production of 

herbicide-resistant corn, including glyphosate-resistant cultivars, and are becoming 

significant export competitors to U.S. corn trade. Because the U.S. and other countries 

already have access to other glyphosate-resistant corn cultivars, and VCO-01981-5 

presents another option of glyphosate-resistant corn, its availability only to U.S. 

producers would not likely significantly impact the economic trade environment. As 

noted above, Genective plans to submit applications to Canada for import clearance of 

VCO-01981-5 (Genective, 2012); however, Canada is not a major U.S. corn export 

competitor. 

As discussed in Subsection 4.4.2, Plant Communities, the cultivation of VCO-01981-5 

would not change the development of glyphosate-resistant weeds nor affect the BMPs to 

control glyphosate-resistant weeds any differently than other nonregulated glyphosateresistant corn. These BMPs would not necessarily increase costs such that the 

competitiveness of U.S. corn and trade economic environment would be affected, as the 

increased costs may be offset by increased yields (Weirich et al., 2011a). 

As discussed under the No Action Alternative, global corn export markets respond to 

many factors, including consumer perception of GE crops and derived products. As 

another glyphosate-resistant corn cultivar, the availability of VCO-01981-5 for 

production in the U.S. would not likely affect foreign consumer perception of GE corn 

products or those global forces shaping the U.S. corn trade economic environment. 

5 CUMULATIVE IMPACTS

A cumulative impact may be an effect on the environment which results from the 

incremental impact of the proposed action when added to other past, present, and 

reasonably foreseeable future actions. For example, the potential effects associated with 

a determination of nonregulated status for a GE crop in combination with the future 

production of crop seeds with multiple deregulated traits (i.e., “stacked” traits), including 

drought tolerance, herbicide resistance, and pest resistance, would be considered a 

cumulative impact. 

5.1 Assumptions Used for Cumulative Impacts Analysis

Cumulative effects have been analyzed for each environmental issue assessed in Section 

4, Environmental Consequences. In this EA, the cumulative effects analysis is focused 

on the incremental impacts of the Preferred Alternative taken in consideration with 

related activities including past, present, and reasonably foreseeable future actions. 

Certain aspects of this product and its cultivation would be no different between the 

alternatives; those instances are described below. In this analysis, if there are no direct or 

indirect impacts identified for a resource area, then APHIS assumes there can be no 

cumulative impacts. Where it is not possible to quantify impacts, APHIS provides a 

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qualitative assessment of potential cumulative impacts. APHIS will limit the analysis of 

cumulative impacts to the areas in the U.S. where corn is commercially produced. 

Potential reasonably foreseeable cumulative effects are analyzed under the assumption 

that farmers, who produce conventional or organic corn and VCO-01981-5, have used in 

the past and would continue to use reasonable, commonly accepted BMPs for their 

chosen system and varieties during agricultural corn production. APHIS recognizes, 

however, that not all farmers will use such BMPs. Further, the cumulative impact 

analysis assumes that it is not necessary to change the use pattern of glyphosate on the 

glyphosate-resistant VCO-01981-5 variety. Hence, APHIS will use current glyphosate 

labels as the basis for its potential past, present, and reasonably foreseeable impacts from 

the use of and exposure to glyphosate. APHIS assumes growers of VCO-01981-5 will 

adhere to the EPA-registered uses and EPA-approved labels for all pesticides applied to 

this crop. 

Crop varieties that contain more than one GE trait, known as a “stacked” hybrid, are 

currently found in agricultural production and in the marketplace. If APHIS approves the

petition for nonregulated status for VCO-01981-5 corn, it would likely be combined with 

non-GE and GE corn varieties through traditional breeding techniques. Stacking of 

nonregulated GE crop varieties using traditional breeding techniques is common practice 

and is not regulated by APHIS. As of 2012, corn with only herbicide-resistant traits 

comprised 21% of the U.S. corn grown, but a greater proportion was stacked with both 

herbicide- and insect-resistant traits (52%) (USDA-NASS (USDA-NASS, 2012a)). 

Stacking would involve combining VCO-01981-5 corn with other corn varieties having 

GE traits such as herbicide, insect, and/or drought resistance, which are no longer subject 

to the regulatory requirements of 7 CFR part 340 or the plant pest provisions of the Plant 

Protection Act. Such stacked varieties could provide growers with several options such 

as combining several herbicides with different modes of action for control of weeds; 

therefore, as part of the cumulative impacts analysis, APHIS will assume that VCO01981-5 corn would likely be combined with commercially available herbicide and 

insect-resistant varieties of corn as a reasonably foreseeable future action.

Whether VCO-01981-5 corn would be stacked with any particular nonregulated GE 

variety is unknown, as company plans and market demands play a significant role in 

those business decisions. In addition, the adoption level of VCO-01981-5 corn would

depend on the extent producers value the traits offered by stacked versions of VCO01981-5 corn over other available stacked corn varieties and comparative pricing 

compared to other HT corn varieties. 

5.2 Cumulative Impacts: Acreage and Area of Corn Production

The Preferred Alternative is not expected to directly cause a measurable change in 

agricultural acreage or area devoted to conventional or GE corn cultivation or corn grown 

for seed in the U.S. (see Subsections 4.2.1, Acreage and Area of Corn Production). The 

majority of corn grown in the U.S. is GE and herbicide resistant (USDA-ERS, 2011a). 

Long-term projections show planted corn maintaining between approximately 90 and 92 

million acres a year through 2020, about the same as the 96 million acres planted to corn 

in 2012 (USDA-OCE, 2011a; USDA-NASS, 2012a). Because VCO-01981-5 is another 

glyphosate-resistant corn cultivar agronomically and compositionally similar to other 

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commercially available glyphosate-resistant corn cultivars, and herbicide-resistant corn is 

currently approximately 73% of all planted corn and most U.S. corn is glyphosateresistant (USDA-NASS, 2012a), it is expected that VCO-01981-5 would replace other 

similar cultivars without expanding the acreage or area of corn production. There are no 

anticipated changes to the availability of GE and non-GE corn varieties on the market 

under either alternative. The Preferred Alternative, therefore, would have no impacts to 

acreage or area of corn production and corn grown for seed different than the No Action 

Alternative.

The potential future development and cultivation of VCO-01981-5 glyphosate-resistant 

corn stacked with other herbicide-resistant, insect-resistant, and/or other GE traits is not 

likely to change the area or acreage of corn production. Despite the availability of these 

cultivars, corn production acreage is expected to remain relatively stable until 2020 

(USDA-OCE, 2011a). 

5.3 Cumulative Impacts: Agronomic Practices

In the preceding analysis, the potential impacts from a determination of nonregulated 

status to VCO-01981-5 corn were assessed. The agronomic characteristics evaluated for 

VCO-01981-5 corn encompassed the entire life cycle of the corn plant and included 

germination, seedling emergence, growth habit, vegetative vigor, days to pollen shed, 

days to maturity, and yield parameters. The compositional analysis included the major 

constituents (carbohydrates, protein, fat, and ash), minerals, vitamins, amino acids, fatty 

acids, secondary metabolites, antinutrients, phytosterols, and nutritional impact. VCO01981-5 corn is agronomically and compositionally similar to other GE and non-GE corn 

varieties (Genective, 2012; USDA-APHIS, 2012a). As a result, and as determined in 

Section 4, Environmental Consequences, the potential impacts under the Preferred 

Alternative for all the resource areas analyzed would be the same as those described for 

the No Action Alternative. 

The potential impacts from the use of herbicides under the Preferred Alternative would 

be the same as those of the No Action Alternative (see Subsections 4.2, Agricultural 

Production of Corn; 4.3, Physical Environment; 4.4, Biological Resources; 4.5, Human 

Health; and 4.6, Animal Feed). The methods of application and use rate for herbicides to 

be applied to VCO-01981-5 corn would not change from those already approved for use 

on other nonregulated glyphosate-resistant corn cultivars. The total amount of the mix of 

herbicides that could be applied to VCO-01981-5 corn would be limited by the 

authorized EPA-registered uses and the total application amount allowed by law. 

Glyphosate and other pesticides are registered by the EPA under FIFRA and are reviewed 

and reregistered every 15 years to assess potential toxicity and environmental impact. In 

order to be registered for use, a pesticide must be able to be used without unreasonable 

risks to people or the environment. Pesticide residue tolerances for glyphosate and other 

herbicides and pesticides are listed in 40 CFR §180.364 and include acceptable 

concentrations for corn grain and forage. In addition, the safety precautions and EPAlabeled instructions for the application of pesticides would not change under the Preferred 

Alternative, ensuring continued human health and worker safety (see Subsection 4.5, 

Public Health). 

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The herbicide glyphosate has been implicated by some in reductions of plant mineral 

uptake or nutrition (see review in (Duke et al., 2012). As noted by Duke (2012) the 

work showing such reduction has almost all been done in the greenhouse on glyphosate 

resistant soybean. Notable also is work that shows such changes in nutrition in response 

to glyphosate are most different at dosage rates beyond the single application label rate 

(Zobiole et al., 2012). Also, although some mineral nutrition depression with glyphosate 

can be detected, these appear to be “within the normal ranges for these crops” (Duke et 

al., 2012). Finally, when field trials are performed using label rates, content of 13 

minerals was not lower following either one or two applications of glyphosate in either 

leaves or seed (Duke et al., 2012). APHIS concludes that there is no consistent evidence 

for an effect of glyphosate on mineral nutrition of soybean, and not likely of corn, either. 

VCO-01981-5 corn stacked with other herbicide-resistant traits would, however, narrow 

the options for herbicidal management of volunteer corn. In crop rotations where 

soybean or some other broadleaf cultivar is rotated with corn, an approved grass 

herbicide could be used to control volunteer corn (Sandell et al., 2011). In continuous 

corn cropping systems with the same herbicide resistances, control becomes more 

complicated and must be accomplished through other means such as tillage (Sandell et 

al., 2011). Loux et al. 2011(2011) recommend careful rotation planning to eliminate this 

potential problem. VCO-01981-5 stacked with insect-resistant traits would be no more 

likely to exhibit increased weediness characteristics than other currently available 

glyphosate- and insect-resistant stacked GE corn cultivars. Similarly, stacked VCO01981-5 is not expected to exhibit any gene flow characteristics different from the parent 

transformation events (i.e., crop lines) that would pose a plant pest risk.

Under the Preferred Alternative, extending a determination of nonregulated status to 

VCO-01981-5 is not expected to result in changes to current corn cropping practices. 

Studies conducted by Genective demonstrate that, in terms of agronomic characteristics 

and cultivation practices, VCO-01981-5 corn is similar to other corn varieties currently 

grown (Genective, 2012; USDA-APHIS, 2012a). Consequently, no changes to current 

corn cropping practices such as tillage, crop rotation, or agricultural inputs associated 

with the adoption of VCO-01981-5 are expected (see Subsection 4.2.2, Agronomic 

Practices). 

5.4 Cumulative Impacts: Organic Corn Production

Based upon recent trends, adding GE varieties to the market is not related to the ability of 

organic production systems to maintain their market share (see Subsection 4.2.3, Organic 

Corn Production). As described above, the majority of corn in 2012 was GE and 

herbicide resistant (USDA-NASS, 2012a). Since 1994, 27 GE corn events or lines have 

been determined by APHIS to be no longer subject to the regulatory requirements of 7 

CFR part 340 or the plant pest provisions of the Plant Protection Act (USDA-APHIS, 

2012b). U.S. organic corn production acreage grew 83% from 32,650 acres in 1995 to 

194,637 acres in 2008, and remained at about 0.2% of total U.S. corn acreage from 2005 

to 2008 (USDA-ERS, 2011g). Availability of another GE glyphosate-resistant corn 

variety, such as VCO-01981-5 under the Preferred Alternative, is not expected to impact 

the organic production of corn any differently than other GE varieties grown in the past 

or presently under the No Action Alternative.

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5.5 Cumulative Impacts: Physical Environment

As discussed in Subsection 4.3, Physical Environment, the Preferred Alternative would 

have the same potential impacts to water, soil, air quality, and climate change as that of 

nonregulated glyphosate-resistant corn varieties presently available. Agronomic 

practices that have the potential to impact soil, water and air quality, and climate change 

such as tillage, agricultural inputs (fertilizers and pesticides), and irrigation would not 

change because VCO-01981-5 is agronomically similar to other glyphosate-resistant corn 

and other GE and non-GE corn. Other practices that benefit these resources, such as 

contouring, use of cover crops to limit the time soil is exposed to wind and rain, crop 

rotation, and windbreaks would also be the same between the No Action and Preferred 

Alternatives. Because of its similarity to other nonregulated glyphosate-resistant corn 

and the fact that most cultivated corn in the U.S. is glyphosate resistant, adoption of 

VCO-01981-5 would replace other similar cultivars without changing the acreage or area 

of corn production that could impact water, soil, air quality, and climate change. No 

difference in impacts to these resources would occur between the Preferred and No 

Action alternatives.

If the petition for nonregulated status for VCO-01981-5 is approved and it is stacked with 

other GE herbicide-resistant traits, depending on the extent of its adoption, it may 

contribute to sustaining conservation tillage in U.S. corn production that both directly and 

indirectly impacts water, soil, and air quality. Stacking VCO-01981-5 with other 

herbicide-resistant traits would enable use of a combination of different herbicide modes 

of action to be applied to corn, an approach recommended by Dill et al. (Dill et al., 2008)

to preserve the utility of glyphosate resistance technology. This approach has been 

proposed to mitigate the future development of herbicide-resistant weeds (Duke and 

Powles, 2009), which may reduce the need for tillage for weed management (Owen, 

2011a), thus, benefiting soil, water, and air quality. Consequently, stacking with 

additional herbicide resistant traits would also reduce GHG emissions from soil and 

emissions from associated fuel-burning equipment that can contribute to climate change. 

Reduced tillage improves habitat value through increased water quality, availability of 

waste grain, retention of cover in fields, and increased populations of invertebrates 

(Brady, 2007; Sharpe, 2010). Similarly, stacking multiple herbicide resistance into a 

single cultivar may sustain conservation tillage rates that promote greater plant diversity 

in fields while retaining crop yields which subsequently would improve soil quality and 

reduce soil erosion, sustaining both crop and non-crop plants (see Subsection 2.2.2, Soil 

Quality). 

5.6 Cumulative Impacts: Biological Resources

The impacts of the Preferred Alternative to animal and plants communities, 

microorganisms, and biodiversity as discussed in Subsection 4.4, Biological Resources 

would be no different than that experienced under the No Action Alternative. VCO01981-5 corn is both agronomically and compositionally similar to other nonregulated 

glyphosate-resistant corn; thus, it would not require any different agronomic practices to 

cultivate, and does not represent a safety or increased weediness risk any differently than 

other currently available glyphosate-resistant corn. Availability of VCO-01981-5 corn 

would not impact the development of glyphosate-resistant weeds or the trend to broaden 

weed management tactics to effect control over herbicide-resistant weeds, as it is 

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expected to replace other glyphosate-resistant cultivars without expanding the acreage or 

area of corn production or changing the application rates of glyphosate (see Subsection 

4.4.2, Plant Communities). 

VCO-01981-5 corn would be another glyphosate-resistant corn cultivar that could be 

stacked like other nonregulated glyphosate-resistant GE corn. Potential future stacking of 

VCO-01981-5 corn might include development of hybrids using other currently available 

nonregulated corn varieties expressing resistance to other herbicides, or resistance to 

select insect pests by stacking with one of the biopesticidal Bt genes. For example, a new 

cultivar combining glyphosate and glufosinate resistance with insect resistance became

available for the 2012 planting season (Monsanto, 2011a). APHIS regulations under 7 

CFR part 340 do not provide for Agency oversight of stacked varieties combining GE 

varieties with previously approved nonregulated status, unless it can be positively shown 

that such stacked varieties are likely to pose a plant pest risk. No evidence suggests an 

impact of such combined traits, and in fact, existing evidence supports the non-impact of 

such stacking. As typically observed, neither glyphosate use nor cultivars with 

glyphosate resistance have a consistent impact on soil microbiota (see sect 4.4.3). 

Similarly neither glufosinate resistant plants nor the herbicide glufosinate changed the 

community profile of rhizosphere bacteria when 16s rRNA was assessed in products of 

PCR analyzed for single-strand conformation polymorphism (Schmalenberger and 

Tebbe, 2002). Whether VCO-01981-5 would be stacked with any particular nonregulated 

GE variety is unknown, as company plans and market demands play a significant role in 

those business decisions. In addition, the adoption level of VCO-01981-5 would depend 

on the extent producers value the traits offered by stacked versions of VCO-01981-5 over 

other available stacked corn varieties. 

VCO-01981-5 corn would likely be stacked with insect-resistant corn varieties that 

express the Bt endotoxin. Based on studies undertaken to assess the potential impacts of 

the Bt endotoxin to the monarch and other non-target butterflies, as well as factors such 

as the location of corn production and the characteristics of corn pollen, the EPA 

determined that the potential risk to non-target butterflies is low (US-EPA, 2002). In the 

near future, any VCO-01981-5 corn stacked with insect-resistant (Bt) traits would likely 

replace other currently nonregulated stacked GE corn varieties with herbicide and insect 

resistance. Any insect-resistant trait that may be developed in the future and stacked with 

VCO-01981-5 would be subject to APHIS, EPA, and FDA approval. The adoption of 

stacked VCO-01981-5 corn would be contingent on the extent growers see value in the 

traits expressed in comparison to other commercially available corn cultivars with similar 

herbicide- and insect-resistant traits.

There are no differences in the potential for gene flow and weediness between the No 

Action and Preferred Action Alternatives. Only limited populations of compatible 

relatives of domesticated corn with limited intercrossing ability are found within the U.S.; 

hence, there is not a significant risk of gene movement between corn and its wild or 

weedy maize relatives (US-EPA, 2010a; USDA-APHIS, 2012a). Additionally, corn seed 

does not possess the characteristics for efficient seed-mediated gene flow, does not 

establish wild or feral populations, and is dependent on human cultivation for survival 

(OECD, 2003; Doebley, 2004). The risk of gene flow and weediness of VCO-01981-5 

corn is no greater than that of other nonregulated glyphosate-resistant corn varieties.

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5.7 Cumulative Impacts: Public Health and Animal Feed

Food and feed derived from GE corn must be in compliance with all applicable legal and 

regulatory requirements and may undergo a voluntary consultation process with the 

FDA prior to release onto the market to identify and discuss relevant safety, nutritional, 

or other regulatory issues regarding the bioengineered food. As discussed in Subsections 

4.5, Public Health and 4.6, Animal Feed, VCO-01981-5 would have no adverse effect to 

human health or livestock. Athenix (a predecessor organization to Genective S.A.) 

submitted data for a new protein consultation for ACE5 EPSPS in 2009, and FDA 

completed their response letter on 15 October 2010. Genective submitted a safety and 

nutritional assessment of food and feed derived from VCO-01981-5 corn to the FDA on 

March 5, 2012 and their decision is pending (BNF-000137). It will be posted on the 

FDA website Final Biotechnology Consultations (http://www.fda.gov/Food 

/Biotechnology/Submissions/ucm225108.htm) when completed. A food safety 

evaluation of the related EPSPS protein for the GA21 corn variety was completed by the 

FDA (BNF No. 000051) on February 10, 1998, which found no safety concerns (USFDA, 1998). In addition, the potential environmental impacts from the cultivation of 

glyphosate-resistant corn varieties have been thoroughly evaluated by APHIS (see 

http://www.aphis.usda.gov/biotechnology /not_reg.html). No differences in food and 

feed safety would be presented when comparing the Preferred and No Action 

alternatives.

Under the preferred alternative, VCO-01981-5 would likely be stacked with insectresistant corn varieties that express the Bt endotoxin. In accordance with 40 CFR part 

174, all the currently nonregulated insect-resistant corn varieties that contain the Bt 

endotoxin are exempt from the requirement of tolerance in feed commodities. In the near 

future, any VCO-01981-5 stacked with insect-resistant (Bt) traits would likely replace 

other currently non-regulated stacked GE corn varieties with herbicide and insect 

resistance. Any insect-resistance trait that may be developed in the future and stacked 

with VCO-01981-5 would be subject to APHIS, EPA, and FDA approval. The adoption 

of stacked VCO-01981-5 corn would be contingent on the extent growers see value in the 

traits expressed in comparison to other commercially available corn cultivars with similar 

herbicide- and insect-resistant traits.

In the near term, any additional GE traits that may be stacked with VCO-01981-5 have

already been deregulated. . As discussed above in Subsection 4.5 Public Health and 4.6 

Animal Feed, food and feed derived from GE corn must be in compliance with all 

applicable legal and regulatory requirements and may undergo a voluntary consultation 

process with the FDA prior to release onto the market. All varieties of GE corn with 

which VCO-01981-5 would be stacked have undergone, or are expected to undergo, this 

process to ensure their safety as food and feed products.

5.8 Cumulative Impacts: Domestic Economic Environment

As discussed above, based on its similarity to other nonregulated corn cultivars, VCO01981-5 corn would potentially replace other glyphosate-resistant corn cultivars without 

impacting corn acreage or production area that may affect domestic markets. 

Additionally, since VCO-01981-5 corn is agronomically and compositionally similar to 

other commercially available corn, there would be no changes to agronomic inputs or 

107
practices from approving the nonregulated status to VCO-01981-5 that may impact onfarm costs for corn producers or the domestic economic environment, including the 

organic corn market. As mentioned above, VCO-01981-5 would not likely impact 

differently the development or treatment of herbicide-resistant weeds or their associated 

costs in crop losses. Nor would methods to effect control of such herbicide resistant 

weeds in VCO-01981-5 differ compared to methods used in other glyphosate resistant

corn hybrids. Impacts of the Preferred Alternative on the domestic economic 

environment would therefore be no different than those sustained under the No Action 

Alternative.

Corn varieties with single and multiple herbicide resistance or insect resistance are 

already widely available, representing 73% of U.S. corn acreage in 2012 (see Subsection 

2.1.1, Acreage and Area of Corn Production). While the adoption of herbicide-resistantonly corn has remained relatively level and the production of insect-resistant-only corn 

has decreased since 2007, the adoption of stacked varieties that confer resistance to 

herbicides and insects has steadily increased from 1% of planted corn acres in 2000 to 

49% in 2011 (USDA-ERS, 2011a). As such, it is expected that VCO-01981-5 corn 

would likely be stacked with insect-resistant traits and would have impacts similar to 

other such stacked corn cultivars already on the market. Agronomic practices, including 

inputs for production of VCO-01981-5 stacked with insect resistance, would be no 

different than those needed to cultivate other commercially available corn with the same 

resistances; thus, changes to on-farm costs for corn producers or to the U.S. domestic 

corn market would be unlikely. VCO-01981-5 corn may also be stacked with other 

nonregulated GE traits; however, predicting these potential combinations would be 

purely speculative. Overall, it is unlikely that any cumulative impact to the domestic 

economic environment would result from a stacked product consisting of VCO-01981-5 

and other readily-available GE traits. 

5.9 Cumulative Impacts: Trade Economic Environment

Under the Preferred Alternative, it is possible VCO-01981-5 corn would not be approved 

for import into other countries. Because the U.S. and other countries already have access 

to other glyphosate-resistant corn cultivars, and VCO-01981-5 corn presents another 

option of glyphosate-resistant corn similar to cultivars already in the marketplace, its 

availability only to U.S. producers would not likely significantly impact the economic 

trade environment. Only 15% of domestically produced U.S. corn is dedicated to the 

export market (USDA-ERS, 2011c), and the extent of VCO-01981-5 corn would be 

dependent on whether growers find value in another glyphosate-resistant cultivar. If 

VCO-01981-5 corn were not approved for import by other countries but would be 

approved as nonregulated in the U.S., it would not likely affect the supply of U.S. corn 

eligible for import to other countries. Likewise, if it were approved both in the U.S. and 

for import by other countries, based on its similarity to other glyphosate-resistant corn 

cultivars and the likelihood it would replace other such cultivars without increasing the 

acreage or area of corn production, VCO-01981-5 corn would still be unlikely to affect 

the supply of U.S. corn available for export. If it were approved in the US, but not for 

import by other countries, growers may find that more limited options were available for 

grain sales (Stebbins and Plume, 2011), but again, any significant impact on exports 

108
would be unlikely because the growers would likely hesitate to grow the crop and large 

quantities would not be produced.

As discussed in Subsection 2.6.2, Trade Economic Environment, U.S. corn exports have 

remained relatively stable over the last decade, a period in which other corn varieties with 

stacked glyphosate and other traits have been brought to market. Global export markets 

respond to many factors and are unlikely to change with the commercial availability of 

another glyphosate-resistant corn cultivar such as VCO-01981-5 corn alone, or stacked 

with other currently available traits.

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6 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, on behalf of the 

American people, passed the ESA to prevent extinctions facing many species of fish, 

wildlife and plants. The purpose of the ESA is to conserve endangered and threatened 

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, non-governmental 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 

endangered or threatened 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. 

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 

critical habitat. To facilitate APHIS’ ESA consultation process, APHIS met with the 

USFWS from 1999 to 2003 to discuss factors relevant to APHIS’s regulatory authority 

and effects analysis for petitions for nonregulated status, and developed a process for 

conducting an effects determination consistent with the Plant Protection Act 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 biotechnology 

regulatory actions. 

APHIS’ regulatory authority over GE organisms under the Plant Protection Act is 

limited to those GE organisms for which it has reason to believe might be a plant pest or 

those for which APHIS does not have sufficient information to determine that the GE 

organism is unlikely to pose a plant pest risk (7 CFR § 340.1). APHIS does not have 

authority to regulate the use of any herbicide, including glyphosate. After completing a 

PPRA, if APHIS determines that VCO-01981-5 corn does not pose a plant pest risk, then 

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VCO-01981-5 corn would no longer be subject to the plant pest provisions of the Plant 

Protection Act or to the regulatory requirements of 7 CFR Part 340, and therefore, APHIS 

must reach a determination that the article is no longer regulated. As part of its EA 

analysis, APHIS is analyzing the potential impacts of VCO-01981-5 corn on the 

environment including any potential effects to threatened and endangered species and 

critical habitat. As part of this process, APHIS thoroughly reviews GE product 

information and data to inform the ESA effects analysis and, if necessary, the biological 

assessment. For each transgene(s)/GE plant 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 GE plant is sexually compatible with any 

threatened or endangered plant species (TES) or a host of any TES.

In following this review process, APHIS has evaluated the potential effects that granting 

a request for determining nonregulated status for VCO-01981-5 corn would have on 

federally-listed TES, proposed species, critical habitat, and proposed critical habitat 

occurring within the 49 corn-producing U.S. states and Puerto Rico. APHIS has 

reviewed USFWS-listed and proposed TES species for each state in which corn is 

commercially produced using the Environmental Conservation Online System (ECOS) 

(Accessed April 04, 2013 from http://ecos.fws.gov/tess_public). Appendix A lists TES 

found in 49 corn-producing U.S. states and Puerto Rico. Prior to this review, APHIS 

considered the potential for VCO-01981-5 corn to extend the range of corn production 

and affect the conversion of land to agricultural purposes. Genective’s studies 

demonstrate VCO-01981-5 corn is similar in its growth habit, agronomic properties, 

disease susceptibility, and composition to its antecedent GA21, its control group 

cultivars, other nonregulated varieties of glyphosate-resistant corn, and other GE and 

non-GE corn (Genective, 2012; USDA-APHIS, 2012a). As such, its cultural 

requirements would be no different than those of other corn or provided by the areas in 

which corn is currently cultivated. As presented in Subsection 2.1.1, Acreage and Area 

of Corn Production, the majority of corn cultivated in the U.S. is herbicide-resistant, most 

of which is glyphosate-resistant (Duke and Powles, 2009; USDA-ERS, 2011a). 

Nonregulated VCO-01981-5 corn could replace other commercially available glyphosateresistant corn varieties without requiring cultivation of new, natural lands. As such, land 

use changes that could decrease TES habitat following APHIS approval of nonregulated

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status for VCO-01981-5 corn are not expected to be any different than those associated 

with the cultivation of other corn cultivars. Accordingly, this analysis focuses on 

potential TES impacts where corn is currently grown. 

APHIS focused its TES review on the implications of exposure to the CP4 EPSPS protein 

in VCO-01981-5 corn, the interaction between TES and VCO-01981-5 corn, including 

the potential for sexual compatibility and the ability to serve as a host for a TES, and the 

ability to affect plants and habitat by naturalizing in the environment. However, in 

furtherance of NEPA, APHIS also considered the potential impacts of the use of 

glyphosate, expected to be used on VCO-01981-5 corn, to non-target organisms and the 

natural environment.

6.1 Potential Effects of VCO-01981-5 corn on TES

This section considers the potential effects of the interaction of TES and VCO-01981-5 

corn, including: (1) its potential as a host for TES species; (2) potential gene flow to 

TES; (3) consumption effects of VCO-01981-5 corn seeds and vegetation; and, (4) 

potential non-target impacts to TES, their habitat, and critical habitat from glyphosate use 

associated with the production of VCO-01981-5 corn.

A review of the listed and proposed TES indicates no members of the corn genus Zea 

serve as a host plant for any Federally-protected species. There are also no listed or 

proposed TES plant species that are sexually compatible or could cross-pollinate with the 

Zea genus in the U.S. As discussed above in the analysis of gene flow and weediness, 

commercially grown corn varieties in the U.S. are not considered weeds because corn 

does not possess characteristics to easily disperse and survive without human intervention 

(OECD, 2003). As presented in Subsections 4.4.2, Plant Communities, and the APHIS 

plant risk assessment (USDA-APHIS, 2012a), the potential for gene flow between VCO01981-5 corn and sexually compatible wild teosinte relatives is low. These species are 

native to tropical and subtropical Mexico and Central America (USDA-APHIS, 2012a). 

While there have been no studies to investigate the introgression of genes from corn into 

U.S. where one rare, highly dispersed population is known in Florida (USDA-APHIS, 

2012a), complex mechanisms of incompatibility have been described that are barriers to 

this potentiality (Kermicle and Evans, 2010). In addition, while corn and various teosinte 

species are culturally and biologically similar, and gene exchange between these groups 

has been documented at low frequencies in Mexico, there has been no evidence of 

successful weedy species developing (US-EPA, 2010a). Based on the agronomic studies 

conducted by Genective and verified by APHIS, extending determination of nonregulated 

status to VCO-01981-5 corn does not present a plant pest risk, a risk of increased 

potential for weediness, nor an increased risk of gene flow, when compared to other 

currently cultivated corn varieties (USDA-APHIS, 2012a). 

Genective/BASF has presented information on the animal feed safety characteristics of 

VCO-01981-5 corn that could impact wildlife that may use cornfields as a food source, 

consuming the plant or insects that live on the plants. Few TES are likely to use 

cornfields because they do not provide suitable habitat; however, some species may visit 

agricultural fields for incidental feeding. Midwestern TES species that occasionally feed 

in farmed sites include: whooping crane (Grus americana), sandhill crane (Grus 

canadensis pulla), piping plover (Charadrius melodus), and interior least tern (Sterna 

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antillarum) (USFWS, 2011a). These and other bird species may visit cornfields during 

migratory periods, but would not be present during normal farming operations (Krapu et 

al., 2004; USFWS, 2011a). The Delmarva fox squirrel (Sciurus niger cinereus), which 

inhabits mature forests of mixed hardwoods and pines, may be found adjacent to 

agricultural areas of the Delmarva Peninsula (USFWS, 2011b). The Delmarva fox 

squirrel feeds primarily on acorns, nuts, and pine seeds, but also utilizes corn in adjacent 

agricultural fields (USFWS, 2011b). The Louisiana black bear (Ursus americanus 

luteolus), occurring in Louisiana, Mississippi, and Texas (USFWS, 2011c), may 

occasionally forage on corn (Mississippi State University, No Date).

As discussed in Subsection 4.6, Animal Feed, there is no difference in the composition 

and nutritional quality of VCO-01981-5 corn compared with conventional corn 

(Genective, 2012); no expected hazards are associated with its consumption. The FDA 

has previously evaluated the safety of GE corn cultivars containing the EPSPS protein, 

which included toxicity and allergenicity assessments, finding no safety concern Based 

on this information, no effects on TES are expected from consumption or exposure to

VCO-01981-5 corn.

After reviewing the possible effects of allowing the unregulated environmental release of 

VCO-01981-5 corn, APHIS has not identified any stressor that could affect the 

reproduction, numbers, or distribution of a listed TES or species proposed for listing. As 

a result, a detailed exposure analysis for individual species is not necessary. APHIS also 

considered the potential effect of extending a determination of nonregulated status to 

VCO-01981-5 corn on designated critical habitat or habitat proposed for designation, and 

could identify no differences from effects that would occur from the production of other 

corn varieties. Corn is not considered a particularly competitive plant species and has 

been selected for domestication and cultivation under conditions not normally found in 

natural settings (US-EPA, 2010a). Corn is not sexually compatible with, or serves as a 

host species for, any listed species or species proposed for listing. Consumption of VCO01981-5 corn by any listed species or species proposed for listing would not result in a 

toxic or allergic reaction. Based on these factors, APHIS has concluded that extending 

nonregulated status to VCO-01981-5 corn and the corresponding environmental release 

of this corn variety would 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 

concurrence of the USFWS or NMFS is not required.

6.2 Potential Effects of the Use of Glyphosate

APHIS met with USFWS officials on June 15, 2011 to discuss whether APHIS has any 

obligations under the ESA regarding analyzing the impacts of herbicide use associated 

with all GE crops on TES. As a result of these joint discussions, the USFWS and APHIS 

have agreed that it is not necessary for APHIS to perform an ESA effects analysis on 

herbicide use associated either with VCO-01981-5 corn or with all GE crops currently 

planted because the EPA has both complete regulatory authority over the labeling of 

pesticides and the necessary technical expertise to assess pesticide effects on the 

environment under FIFRA. APHIS has no statutory authority to authorize or regulate the 

use of glyphosate, or any other herbicide, by corn growers. Under Part 340 regulations,

APHIS only has authority to regulate VCO-01981-5 corn or any GE organism as long as 

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the agency believes it may pose a plant pest risk. APHIS has no regulatory jurisdiction 

over any other risks associated with GE organisms including risks resulting from the use 

of herbicides or other pesticides on those organisms. Nevertheless, APHIS is aware that 

there may be potential environmental impacts resulting from the use of glyphosate on 

VCO-01981-5 corn, including potential impacts on TES and critical habitat, based on 

assessments provided by the EPA, and in peer reviewed scientific literature. APHIS is 

providing the available information of potential environmental impacts resulting from 

glyphosate use on VCO-01981-5 corn below.

6.2.1 EPA Endangered Species Protection Program (ESPP)

On October 7, 1988, Congress enacted Public Law 100-478 to in part address the 

relationship between the ESA and EPA’s pesticide labeling program (Section 1010) by 

requiring EPA to conduct a study, and report to Congress, on ways to implement EPA’s 

endangered species pesticide labeling program in a manner that both complies with the 

ESA and allows people to continue production of agricultural food and fiber. This law 

provided a clear sense that Congress wanted EPA to fulfill its obligation to conserve 

listed species, while at the same time consider the needs of agriculture and other pesticide 

users (70 FR 66392). 

In 1988, EPA established the ESPP to meet its obligations under the ESA. The EPA’s 

Endangered Species Protection Program website (http://www.epa.gov/espp/) describes 

the EPA assessment process for endangered species. Some of the elements of that 

process are summarized below. The goal of EPA's ESPP is to carry out its 

responsibilities under FIFRA in compliance with the ESA without placing unnecessary 

burden on agriculture and other pesticide users consistent with Congress’s intent. EPA is 

responsible for reviewing pesticide information and data to determine whether a pesticide 

product may be registered for a particular use, including those uses associated with the 

approval of biotechnology products. As part of that determination, the Agency assesses 

whether listed endangered or threatened species or their designated critical habitat may be 

affected by use of the pesticide product. All pesticide products that EPA determines 

“may affect” a listed species or its designated critical habitat may be subject to the ESPP. 

If limitations on pesticide use are necessary to protect listed species in areas where a 

pesticide may be used, the information is related through Endangered Species Protection 

Bulletins. Bulletins identify the species of concern and the pesticide active ingredient 

that may affect the listed species. They also provide a description of the protection 

measures necessary to protect the species, and contain a county-level map showing the 

geographic area(s) associated with the protection measures, depending on the 

susceptibility of the species. Bulletins are enforceable as part of the product label 

(http://www.epa.gov/oppfead1/endanger/basic-info.htm).

6.2.2 EPA TES Evaluation Process

The EPA evaluates listed species and their critical habitat concerns within the context of 

pesticide registration and registration review so that when a decision is made, it fully 

addresses issues relative to listed species protection. If a risk assessment determines that 

use limitations are necessary to ensure that legal use of a pesticide will not harm listed 

species or their critical habitat, EPA may either change the terms of the pesticide 

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registration or establish geographically specific pesticide use limitations 

(http://www.epa.gov/oppfead1/endanger/basic-info.htm).

The EPA’s review of the pesticide and its registration decision is independent of APHIS’ 

review and regulatory decisions under 7 CFR part 340. EPA does not require data or 

analyses conducted by APHIS to complete its reviews. The EPA evaluates extensive 

toxicity, ecological effects data, environmental fate, and transport and behavior data, 

most of which is required under FIFRA data requirements, to assess and determine how a 

pesticide will move through and break down in the environment. Risks to various taxa, 

e.g., birds, fish, invertebrates, plants and mammals are routinely assessed and used in 

EPA’s determinations of whether a pesticide may be licensed for use in the U.S.

The EPA’s core pesticide risk assessment and regulatory processes ensure that 

protections are in place for all populations of non-target species, not just TES. The EPA 

has developed a comprehensive risk assessment process modeled after, and consistent 

with, EPA’s numerous guidelines for environmental assessments 

(http://www.epa.gov/oppfead1 /endanger/consultation/ecorisk-overview.pdf). The result 

of an assessment, which may go through several refinements, is to determine whether the 

potential effects of a pesticide’s registration to a listed species will result in either a “no 

effect” or “may affect” determination. The EPA consults on determinations that “may 

affect” a listed species or adversely modify its critical habitat 

(http://www.epa.gov/oppfead1/endanger). As a result of either an assessment or 

consultation, EPA may require changes to the use conditions specified on the label of the 

product. When such changes are necessary only in specific geographic areas rather than 

nationwide to ensure protection of the listed species, EPA implements these changes 

through geographically-specific Endangered Species Protection Bulletins; otherwise, 

these changes are applied to the label for all uses of the pesticide.

6.2.3 Ecological Risks of Glyphosate

The ecological risks associated with use of glyphosate as an herbicide have been assessed 

several times since 1974 when it was first registered for use in the U.S. In addition, EPA 

has consulted with the USFWS on the effects of glyphosate on listed species and critical 

habitat. Findings from relevant ecological risk assessments and the results and status of 

consultations are summarized below.

In the June 1986 Registration Standard for glyphosate, the EPA discussed consultations 

with the USFWS on hazards to crops, rangeland, silvicultural sites, and the Houston toad 

which may result from the use of glyphosate. Because a jeopardy opinion resulted from 

these consultations, the agency imposed endangered species labeling requirements in the 

Registration Standard to mitigate the risk to endangered species.

In 1993, glyphosate was assessed by the EPA for the RED (US-EPA, 1993b). The RED 

concluded that direct risks to birds, mammals, invertebrates, and fish would be minimal. 

Under certain conditions, aquatic plants were expected to be at risk from glyphosate use. 

Additional data were needed for non-target terrestrial plants, including incident data and 

vegetative vigor testing on non-target terrestrial plants. The assessment stated that many 

endangered plants may be at risk from use of glyphosate with the registered use patterns. 

In addition, it was determined that the Houston toad may be at risk from use of 

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glyphosate on alfalfa. The RED resulted in label changes to provide protection of aquatic 

organisms.

In 2003, the USDA’s Forest Service had a risk assessment conducted for glyphosate uses 

in Forest Service vegetation management programs (USDA-FS, 2003). For forestry uses, 

all commercial formulations of glyphosate contained the isopropylamine salt of 

glyphosate. Application rates ranged from 0.5 pounds acid equivalent per acre (lb ae/Ac) 

to 7 lb ae/Ac with the most typical at 2 lb ae/Ac. Based on the available data, the USDA 

concluded that the risks were minimal to mammals, birds, fish, amphibians, invertebrates, 

and aquatic plants. Risks to fish following application of the more toxic formulations 

were not considered to be high; however, the assessment did state that at an application 

rate of 7 lb ae/Ac, the acute exposures slightly exceeded the acute LC50 for a more 

tolerant freshwater fish and exceeded it by a factor of 2 for the less tolerant fish. These 

values were estimated from a worst-case scenario where there was a severe rainfall of 

about 7 inches over a 24-hour period in an area where runoff is favored. USDA did not 

conduct a separate assessment for amphibians. The document concluded the amphibian 

data indicated glyphosate is no more toxic to amphibians than it is to fish. For terrestrial 

plants, the assessment concluded that for relatively tolerant plants, when a low-boom 

spray is utilized as the method of application, there is no indication glyphosate would 

result in damage from spray drift at distances from the application site of 25 feet or 

greater. For more sensitive plants, the distance increased to approximately 100 feet. For 

applications requiring the use of backpack-directed spray, the distances would be less. 

No risks to terrestrial plants from runoff were expected.

In 2004, the EPA issued a report, “Glyphosate Analysis of Risks to Endangered and 

Threatened Salmon and Steelhead”. The analysis included 11 Evolutionary Significant 

Units (ESU) - a population that is considered distinct for purposes of conservation - in 

California with one unit extending into southern Oregon. Much of the quantitative 

information presented and used was derived from the 1993 RED Ecological Risk 

Assessment. Testing was performed with formulated products, in addition to glyphosate 

alone, and included acute and chronic toxicity. Testing of the pure product indicate that 

pure glyphosate is practically non-toxic to the species examined. Glyphosate was 

moderately toxic to practically non-toxic in formulated products. Since this is somewhat 

increased over results with the pure chemical, the report concluded that it appears likely 

due to the added agents, generally surfactants. The EPA uses a variety of chemical fate 

and transport data to develop “estimated environmental concentrations” (EECs) from a 

suite of established models. The EECs were used with toxicity for the most sensitive 

species from technical grade testing of the active ingredient to develop acute risk 

quotients (RQs). The RQ analysis indicates that glyphosate applied at 5.062 pounds 

active ingredient per acre (lb ai/Ac) does not present an acute risk to endangered and 

threatened salmonids from direct effects because the calculated RQ is less than the level 

of concern (LOC). The primary indirect effect of concern would be for the food source 

for listed fish. The report concluded that this rate of application does not present indirect 

effects from loss of food or loss of cover, as the RQs for invertebrates and plants is less 

than the LOC. However, the assessment determined that use of glyphosate “may affect, 

but is not likely to adversely affect” the species based on acute toxicity to fish for uses 

with application rates above 5 lb ai/Ac. For uses with application rates below 5 lb ai/Ac, 

the Agency determined glyphosate would have no effect on the 11 ESUs.

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In 2006, the EPA assessed glyphosate for a new use on bentgrass (US-EPA, 2006a) (0.74 

lb ai/Ac) and for new uses on Indian mulberry (noni), dry peas, lentils, garbanzo (USEPA, 2006b), safflower, and sunflower (US-EPA, 2006c), with the highest proposed 

ground application rate of 3.73 lb ae/Ac. For all proposed new uses, the EPA concluded 

that there was minimal risk of direct acute effects to terrestrial animals (birds and 

mammals) and aquatic animals (fish, amphibians, and invertebrates) and minimal risk to 

terrestrial plants (both non-target and endangered plant species), aquatic non-vascular 

(algae and diatoms) and vascular (duckweed) plants from off-target spray drift and runoff 

from ground-based applications. In addition, there were no chronic risks to animals.

In 2008, as a part of EPA’s TES effects assessment for the California red-legged frog 

(CRLF), EPA evaluated the effect of glyphosate use at rates up to 7.95 lb ae/Ac on fish, 

amphibians, aquatic invertebrates, aquatic plants, birds, mammals, and terrestrial 

invertebrates (US-EPA, 2008). This assessment determined that at the maximum 

application rate for in-crop applications of glyphosate to glyphosate-resistant corn (8 

aerial applications of 0.75 lb ae/Ac and 2 ground applications of 3.75 and 2.25 lb ae/Ac), 

there would be no effects of glyphosate use on the following taxa of TES: fish, 

amphibians, birds, and mammals. The EPA assessment was uncertain of the effects on 

terrestrial invertebrates, citing the potential to affect small insects at all application rates 

and large insects at the 7.95 lb ae/Ac acre rate which is above the maximum rate for 

glyphosate-resistant corn.

In 2010, EPA issued the memorandum Assessment of Ecological Risk for Glyphosate, 

potassium salt (Pesticide Chemical Code 103613; Chemical Abstract Service Number 

(CAS#) 70901-12-1) for Label Supplement to Add Uses on Roundup Ready Sweet Corn. 

Because of the potential risk from surfactants, a conservative estimation of risk to aquatic 

organisms was conducted on a formulation basis as well as on a glyphosate acid 

equivalent basis. The names and CAS numbers of the surfactant are proprietary and are 

not provided in the assessment. Instead the surfactant POEA mixture (CAS # 61791-26-

2) was used because it has been used in glyphosate products and is known to be 

considerably more toxic to aquatic organisms than technical glyphosate. The assessment 

was completed with the assumption that the proposed surfactants are similar to POEA. 

Based on the proposed labels, the maximum application rate on a glyphosate acid 

equivalent basis is 3.71 lb ae/Ac glyphosate and on a formulation basis is 9.35 lb 

formulation/Ac. The risk to fish, aquatic phase amphibians, aquatic invertebrates, aquatic 

plants, birds, reptiles, terrestrial phase amphibians, mammals, terrestrial invertebrates, 

and terrestrial plants was analyzed. The assessment concluded that there was no risk to 

fish, aquatic phase amphibians, aquatic invertebrates, aquatic plants, and mammals 

because the RQs did not exceed the LOCs for any of these groups. Because of the lack of 

toxicity studies for reptiles and terrestrial phase amphibians, birds are used as a surrogate. 

None of the available acute and subacute avian studies showed mortality so RQs were not 

calculated for birds. All of the terrestrial EEC values are lower than the highest 

dose/concentration tested (3.71 lb ae/Ac glyphosate), but many of the EECs for 20-gram 

birds were greater than 1/10th of that dose. For 100-gram birds, several EECs were 

greater than 1/10th of the highest dose and with the 1.15 lb ae/Ac dose applied 4 times 

per season; therefore, there is uncertainty associated with the effect to listed birds, 

reptiles, and terrestrial phase amphibians. The chronic LOC for birds (LOC = 1) was 

exceeded for application to short grasses at the highest dose (3.71 lb ae/Ac glyphosate) 

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(RQ = 1.07). However, because there were no effects at the highest concentrations in the 

bird studies and the RQ was only slightly greater than the LOC, the risk following 

chronic exposure is expected to be minimal. The assessment concluded that the risk to 

terrestrial invertebrates is negligible based on glyphosate’s classification as practically 

non-toxic to honeybees. Lastly, for listed terrestrial plants, the RQ is lower than the LOC 

at the highest application rate when applied via ground applications, but are exceeded for 

listed and non-listed monocots and dicots when aerially applied at this 3.71 lb ae/Ac 

glyphosate rate.

The EPA is currently conducting a registration review for glyphosate (US-EPA, 2009d). 

EPA plans to conduct comprehensive human health and ecological risk assessments, 

including an endangered species assessment for uses and formulations of glyphosate, 

including risks due to surfactants included in formulations designated only for terrestrial 

applications. The EPA estimates completing the registration review in 2015. The 

ecological risk assessment planned during the registration review will allow EPA to 

determine whether glyphosate’s use has “no effect” on or “may affect” federally listed 

TES or their designated critical habitat. When an assessment concludes that a pesticide’s 

use “may affect” a listed species or its designated critical habitat, EPA will consult with 

the USFWS and/or NMFS, as appropriate, and may develop labels that restrict the 

pesticide’s use or specify certain conditions, e.g., minimum separation distances between 

areas sprayed with glyphosate-based herbicides and habitats of TES.

6.2.4 Potential Impacts of Glyphosate Use in the Production of Corn

Under the Preferred Alternative, Genective does not propose any change in the currently 

permitted uses of glyphosate (Genective, 2012). As discussed in Subsection 4.2.1, 

Acreage and Area, VCO-01981-5 corn would not require new natural lands to be 

converted to agricultural use. Corn is widely produced throughout 49 states; in 2012, 

73% of planted corn was herbicide-resistant. As described in Subsection 4.2.2, 

Agronomic Practices, VCO-01981-5 corn also does not have cultural requirements 

different from other glyphosate-resistant corn varieties that would change glyphosate 

application rates to corn. Of the 98% of planted corn that received herbicide applications 

in 19 survey states in 2010, 66% were treated with glyphosate (USDA-NASS, 2011c)

(see Subsection 2.1.2, Agronomic Practices). As discussed in Subsection 4.2.2, 

Agronomic Practices, VCO-01981-5 corn is anticipated to replace other glyphosateresistant corn cultivars and no change to the registered use of glyphosate is proposed; as 

such, no change to the use rate of glyphosate is expected as a result of extending VCO01981-5 corn nonregulated status. 

As discussed above, the goal of EPA's ESPP is to carry out its responsibilities under 

FIFRA in compliance with the ESA. As part of the registration and reregistration 

process, EPA reviews pesticide products to ensure they meet the requirements of FIFRA 

and ESA, and to assess whether listed endangered or threatened species or their 

designated critical habitat may be affected by use of the pesticide product. An 

assessment and subsequent consultation in which a “may affect” determination is made 

may require changes to the use conditions specified on the label of the product. States 

have primary authority for compliance monitoring and enforcing use of pesticides by the 

label requirements. Violators of the regulations are liable for all negative consequences 

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of their actions (FIFRA 7 U.S.C. 136j (a)(2)(G) Unlawful Acts); therefore, growers that 

use glyphosate are very likely to follow its label restrictions. 

In summary, glyphosate would likely continue to be a major component of weed 

management in corn production and no changes in agronomic practices are expected as a 

consequence of extending a nonregulated determination to VCO-01981-5 corn. In 

addition, pesticide labels require precautions be taken to protect TES. For these reasons, 

glyphosate use resulting from a nonregulated determination for VCO-01981-5 corn does 

not present an increase in potential impacts to TES.

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7 CONSIDERATION OF EXECUTIVE ORDERS, STANDARDS, AND 

TREATIES RELATING TO ENVIRONMENTAL IMPACTS

7.1 Executive Orders with Domestic Implications

The following executive orders require consideration of the potential impacts of the 

Federal action to various segments of the population.

• Executive Order (EO) 12898 (US-NARA, 2010a), "Federal Actions to 

Address Environmental Justice in Minority Populations and Low-Income 

Populations," requires Federal agencies to conduct their programs, policies, 

and activities that substantially affect human health or the environment in a 

manner so as not to exclude persons and populations from participation in or 

benefiting from such programs. It also enforces existing statutes to prevent 

minority and low-income communities from being subjected to 

disproportionately high and adverse human health or environmental effects. 

• EO 13045, “Protection of Children from Environmental Health Risks and 

Safety Risks,” acknowledges that children may suffer disproportionately from 

environmental health and safety risks because of their developmental stage, 

greater metabolic activity levels, and behavior patterns, as compared to adults. 

The EO (to the extent permitted by law and consistent with the agency’s 

mission) requires each Federal agency to identify, assess, and address 

environmental health risks and safety risks that may disproportionately affect 

children.

The No Action and Preferred Alternatives were analyzed with respect to EO 12898 and 

EO 13045. Neither alternative is expected to have a disproportionate adverse effect on 

minorities, low-income populations, or children. 

Available mammalian toxicity data associated with the EPSPS protein establish the safety 

of VCO-01981-5 corn and its products to humans, including minorities, low-income 

populations, and children who might be exposed to them through agricultural production 

and/or processing. No additional safety precautions would need to be taken with 

nonregulated VCO-01981-5 corn. 

Human toxicity has also been thoroughly evaluated by the EPA in its development of 

pesticide labels for glyphosate (US-EPA, 1993b; US-EPA, 2009c; US-EPA, 2009d). 

Pesticide labels include use precautions and restrictions intended to protect workers and 

their families from exposures. APHIS assumes that growers will adhere to herbicide use 

precautions and restrictions. As discussed in Subsection 4.5, Public Health, the potential 

use of glyphosate on VCO-01981-5 corn at the proposed application rates would be no 

more than that currently approved for other nonregulated glyphosate-resistant corn and 

found by the EPA not to have adverse impacts to human health when used in accordance 

with label instructions. It is expected that the EPA and ERS would monitor the use of 

VCO-01981-5 corn to determine impacts on agricultural practices, such as chemical use, 

as they have done previously for herbicide-resistant products.

Based on these factors, a determination of nonregulated status of VCO-01981-5 corn is 

not expected to have a disproportionate adverse effect on minorities, low-income 

populations, or children.

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The following executive order addresses Federal responsibilities regarding the 

introduction and effects of invasive species:

EO 1311 (US-NARA, 2010a), “Invasive Species,” states that Federal 

agencies take action to prevent the introduction of invasive species, to 

provide for their control, and to minimize the economic, ecological, and 

human health impacts that invasive species cause. 

Field corn is not listed in the U.S. as a noxious weed species by the Federal government,

nor is it listed as an invasive species by major invasive plant data bases (USDA-NRCS, 

2010). As discussed in Subsection 2.3.3, Gene Flow and Weediness, cultivated corn seed 

does not have the ability to survive in the wild and requires human involvement for seed 

dispersion (OECD, 2003). In addition, corn seed lacks dormancy, will not produce a 

persistent seed bank, and is large and heavy and not easily dispersed by wind or water 

(Mallory-Smith and Zapiola, 2008); therefore, the chance of corn becoming invasive as a 

result of seed dispersion is not likely. As discussed in Subsection 2.3.3, Gene Flow and 

Weediness, there are some populations of closely related and sexually compatible 

subspecies of Z. mays within the U.S.; however, these populations are small and are 

limited to collections in botanical gardens, some feral populations in some southeastern 

states, and small forage crops in some western states. While corn and various teosinte 

species are culturally and biologically similar, and gene exchange between these groups 

has been documented, no successful weedy species has evolved and the potential for gene 

flow between Z. mays and sexually compatible wild relatives is not considered a 

significant agricultural or environmental risk (US-EPA, 2010a). As such, the potential 

for a weedy species of corn to develop as a result of outcrossing with VCO-01981-5 corn

is considered to be highly unlikely. 

Volunteer corn can become extensive in crop fields, competing with desired crops for 

light, moisture, and nutrients (Wilson et al., 2011b). There have been reports of some 

volunteer glyphosate-resistant corn occurring in fields, even if glyphosate-resistant corn 

was not planted the previous year, thought to be a result of transgene pollen movement 

(Beckie and Owen, 2007). While pollen mediated gene transfer can occur, as discussed 

in Subsection 2.3.3, Gene Flow and Weediness, gene flow decreases rapidly with 

separation distance. Recommended methods to control volunteer corn include using a 

combination of techniques such as alternating the glyphosate-resistant corn with non-GE 

crops, or with GE crop cultivars having resistance to herbicides with different modes of 

action, and then application of that herbicide post-emergence. For example, growers 

could plant LibertyLink® soybean and treat it with glufosinate (Beckie and Owen, 2007). 

Others successfully utilize graminicides to control glyphosate-resistant corn in crops not 

susceptible to the herbicide. See Subsection 2.3.2, Plant Communities, for a more 

extensive discussion on controlling volunteer corn. Non-GE corn, as well as other GE 

herbicide-resistant corn varieties, is widely grown in the U.S. Based on historical 

experience with these varieties, and the data submitted by the developer and reviewed by 

APHIS, VCO-01981-5 corn plants are similar in fitness characteristics to other corn 

varieties currently grown; hence, they are not expected to become weedy or invasive 

(USDA-APHIS, 2012a).

121
The following executive order requires the protection of migratory bird populations:

EO 13186 (US-NARA, 2010a), “Responsibilities of Federal Agencies to 

Protect Migratory Birds,” states that federal agencies taking actions that 

have, or are likely to have, a measurable negative effect on migratory bird 

populations are directed to develop and implement, within two years, a 

Memorandum of Understanding (MOU) with the Fish and Wildlife 

Service that shall promote the conservation of migratory bird populations. 

Migratory birds may be found in cornfields as corn is a nutrient-rich food source for fat 

synthesis prior to migration (Krapu et al., 2004). Several species of birds are also known 

to forage for insects and seeds found in and adjacent to cornfields (Best et al., 1990; 

Tremblay et al., 2001; Puckett et al., 2009). As discussed in Subsection 4.4.1, Animal 

Communities, data submitted by the developer indicates that levels of key nutrients, 

minerals, antinutrients, and secondary metabolites in VCO-01981-5 corn were similar to 

the comparators, by extension the antecedent GA21 variety, and other commercial corn 

varieties (Genective, 2012). As discussed in Subsection 2.5, Animal Feed, a final food 

consultation with the FDA for VCO-01981-5 corn was submitted by Genective on March 

5, 2012 and is still pending. It will be posted on the FDA website Final Biotechnology 

Consultations when completed. The food safety of the EPSPS protein conveying 

glyphosate resistance was previously assessed by the FDA in an earlier food safety 

evaluation, and as such no new evaluation is required for VCO-01981-5 corn commercial 

distribution (US-FDA, 2011). Based on APHIS’ assessment of VCO-01981-5 corn, it is 

unlikely that a determination of nonregulated status would have a negative effect on 

migratory bird populations.

The environmental effects associated with glyphosate are summarized in the EPA RED 

for the herbicide (US-EPA, 1993b). Testing indicates that ecological toxicity of 

glyphosate is no more than slightly toxic to birds and does not exceed the agency’s LOC 

(US-EPA, 1993b); however, in accordance with new requirements under 40 CFR part 

158, acute avian oral toxicity data for a passerine species (perching birds) is required for 

the current glyphosate registration review. Based on these factors, it is unlikely that a 

determination of nonregulated status VCO-01981-5 corn would have a negative effect on 

migratory bird populations.

7.2 International Implications

EO 12114 (US-NARA, 2010a), “Environmental Effects Abroad of Major Federal 

Actions” requires federal officials to take into consideration any potential environmental 

effects outside the U.S., its territories, and possessions that result from actions being 

taken. 

APHIS has given this EO careful consideration and does not expect a significant 

environmental impact outside the U.S. in the event of a determination of nonregulated 

status of VCO-01981-5 corn. All existing national and international regulatory 

authorities and phytosanitary regimes that currently apply to introductions of new corn 

cultivars internationally apply equally to those covered by an APHIS determination of 

nonregulated status under 7 CFR part 340. 

122
Any international trade of VCO-01981-5 corn subsequent to a determination of 

nonregulated status of the product would be fully subject to national phytosanitary 

requirements and be in accordance with phytosanitary standards developed under the 

International Plant Protection Convention (IPPC, 2010). The purpose of the IPPC “is to 

secure a common and effective action to prevent the spread and introduction of pests of 

plants and plant products and to promote appropriate measures for their control” (IPPC, 

2010). The protection it affords extends to natural flora and plant products and includes 

both direct and indirect damage by pests, including weeds. 

The IPPC establishes a standard for the reciprocal acceptance of phytosanitary 

certification among the nations that have signed or acceded to the Convention (172 

countries as of March 2010). In April 2004, a standard for PRA of living modified 

organisms (LMOs) was adopted at a meeting of the governing body of the IPPC as a 

supplement to an existing standard, International Standard for Phytosanitary Measure No. 

11 (ISPM-11, Pest Risk Analysis for Quarantine Pests). The standard acknowledges that 

all LMOs will not present a pest risk and that a determination needs to be made early in 

the PRA for importation as to whether the LMO poses a potential pest risk resulting from 

the genetic modification. APHIS pest risk assessment procedures for 

geneticallyengineered organisms are consistent with the guidance developed under the 

IPPC. In addition, issues that may relate to commercialization and transboundary 

movement of particular agricultural commodities produced through biotechnology are 

being addressed in other international forums and through national regulations.

The Cartagena Protocol on Biosafety is a treaty under the United Nations Convention on 

Biological Diversity (CBD) that established a framework for the safe transboundary 

movement, with respect to the environment and biodiversity, of LMOs, which include 

those modified through biotechnology. The Protocol came into force on September 11, 

2003, and 160 countries are Parties to it as of December 2010 (CBD, 2010). Although 

the U.S. is not a party to the CBD, and thus not a party to the Cartagena Protocol on 

Biosafety, U.S. exporters will still need to comply with those regulations that importing 

countries which are Parties to the Protocol have promulgated to comply with their 

obligations. The first intentional transboundary movement of LMOs intended for 

environmental release (field trials or commercial planting) will require consent from the 

importing country under an advanced informed agreement (AIA) provision, which 

includes a requirement for a risk assessment consistent with Annex III of the Protocol and 

the required documentation.

LMOs imported for food, feed, or processing (FFP) are exempt from the AIA procedure, 

and are covered under Article 11 and Annex II of the Protocol. Under Article 11, Parties 

must post decisions to the Biosafety Clearinghouse database on domestic use of LMOs 

for FFP that may be subject to transboundary movement. To facilitate compliance with 

obligations to this protocol, the U.S. Government has developed a website that provides 

the status of all regulatory reviews completed for different uses of bioengineered products

(NBII, 2010). These data will be available to the Biosafety Clearinghouse. 

APHIS continues to work toward harmonization of biosafety and biotechnology 

consensus documents, guidelines, and regulations, including within the North American 

Plant Protection Organization (NAPPO), which includes Mexico, Canada, and the U.S., 

and within the Organization for Economic Cooperation and Development (OECD). 

123
NAPPO has completed three modules of the Regional Standards for Phytosanitary 

Measures (RSPM) No. 14, Importation and Release into the Environment of Transgenic 

Plants in NAPPO Member Countries (NAPPO, 2003).

APHIS also participates in the North American Biotechnology Initiative (NABI), a forum 

for information exchange and cooperation on agricultural biotechnology issues for the 

U.S., Mexico, and Canada. In addition, bilateral discussions on biotechnology regulatory 

issues are held regularly with other countries including Argentina, Brazil, Japan, China, 

and Korea.

7.3 Compliance with Clean Water Act and Clean Air Act

This EA evaluated the potential changes in corn production associated with a 

determination of nonregulated status to VCO-01981-5 corn (see Subsections 4.2.1, 

Acreage and Area and 4.2.2 Agronomic Practices) and determined that the cultivation of 

VCO-01981-5 corn would not lead to the increase in, or expand the area of, corn 

production that could impact water resources or air quality any differently than currently 

cultivated corn varieties. The herbicide resistance conferred by the genetic modification 

to VCO-01981-5 corn is not expected to result in any changes in water usage for 

cultivation compared to current corn production. As discussed in Subsections 4.3.1, 

Water Resources, and 4.3.3, Air Quality, there are no expected significant negative 

impacts to water resources or air quality from potential use of glyphosate or other 

pesticides associated with VCO-01981-5 corn production. Based on these analyses, 

APHIS concludes that a determination of nonregulated status for VCO-01981-5 corn

would comply with the CWA and the CAA.

7.4 Impacts on Unique Characteristics of Geographic Areas

A determination of nonregulated status of VCO-01981-5 corn is not expected to impact 

unique characteristics of geographic areas such as parklands, prime farmlands, wetlands, 

wild and scenic areas, or ecologically critical areas.

Genective has presented results of agronomic field trials for VCO-01981-5 corn that 

demonstrate there are no differences in agronomic practices, between VCO-01981-5 corn

and currently available glyphosate-resistant corn varieties like GA21 (Genective, 2012; 

USDA-APHIS, 2012a). The common agricultural practices that would be carried out in 

the cultivation of VCO-01981-5 corn are not expected to deviate from current practices, 

including the use of EPA-registered pesticides. The product is expected to be cultivated 

by growers on agricultural land currently suitable for production of corn, and is not 

anticipated to expand the cultivation of corn to new, natural areas. 

The Preferred Alternative does not propose major ground disturbances or new physical 

destruction or damage to property, or any alterations of property, wildlife habitat, or 

landscapes; moreover, no prescribed sale, lease, or transfer of ownership of any property 

is proposed. This action is limited to a determination of nonregulated status to VCO01981-5 corn. This action would not convert land use to non-agricultural use and, 

therefore, would have no adverse impact on prime farmland. Standard agricultural 

practices for land preparation, planting, irrigation, and harvesting of plants would be used 

on agricultural lands planted to VCO-01981-5 corn, including the use of EPA-registered 

124
pesticides. The Applicant’s adherence to EPA label use restrictions for all pesticides is 

expected to mitigate potential impacts to the human environment. 

With regard to pesticide use, a determination of nonregulated status to VCO-01981-5 

corn is not likely to result in changes to the use of glyphosate on corn, including 

application timing and rates and annual maximum allowable applications. APHIS 

assumes that the grower will closely adhere to EPA label use restrictions for glyphosate. 

Glyphosate was assessed by the EPA in 1993 and is currently under reregistration review 

scheduled for completion in 2015 (US-EPA, 2009b). Potential impacts to unique 

geographic areas have been considered by the EPA in its evaluation of glyphosate. In 

1993, the EPA completed a reregistration analysis for glyphosate which considered 

human health risk and ecological risks associated with potential exposure to glyphosate in 

multiple pathways (US-EPA, 1993b). 

As a result of court orders and settlements, an endangered species assessment evaluating 

the potential impacts of the use of glyphosate on the federally threatened California Red 

Legged Frog is underway (US-EPA, 2009c). The EPA has requested initiation of formal 

consultation with the USFWS under Section 7 of the ESA to address the potential effects 

of glyphosate on the CRLF (US-EPA, 2009c). The EPA’s formal consultation request 

for the CRLF was based on the potential for direct and indirect effects due to decreases in 

prey items, as well as potential impacts to habitat (See Section 6, Threatened and 

Endangered Species).

In 2004, the EPA made a “not likely to adversely affect” determination from the use of 

glyphosate on 11 ESUs of salmon and steelhead in California and an ESU of salmon in 

southern Oregon (US-EPA, 2004) (see Section 6, Threatened and Endangered Species). 

Formal consultation with the NMFS was initiated by EPA on October 12, 2004 to fulfill a 

Consent Decree entered into between EPA and the Californians’ for Alternatives to 

Toxics in regards to the potential effects of various pesticides usage on plants and certain 

threatened and endangered salmon or steelhead species. 

While this consultation is ongoing, the EPA has allowed glyphosate to remain on the 

market, and it is approved for continued use in accordance with all label requirements. 

Submittals to this analysis can be found at the Regulations.gov website under docket 

designation EPA-HQ-OPP-2009-0361. 

The Agency plans to conduct a comprehensive ecological risk assessment, including an 

endangered species assessment, for all uses of glyphosate and its salts (US-EPA, 2009c). 

Assessments to determine impacts on unique geographic areas include:

• An ecological risk assessment to determine whether the use of glyphosate has “no 

effect” or “may affect” federally listed TES or their designated critical habitat; 

and

• A spray drifts buffer zone analysis to evaluate potential exposure reductions to 

non-target aquatic and terrestrial plants.

The information gathered during the ecological and endangered species risk assessment 

will be used by the EPA to make the registration review decision.

125
Based on these findings, including the assumption that label use restrictions are in place 

to protect unique geographic areas and that those label use restrictions are adhered to, a 

determination of nonregulated status to VCO-01981-5 corn is not expected to impact 

unique characteristics of geographic areas such as park lands, prime farm lands, wetlands, 

wild and scenic areas, or ecologically critical areas.

7.5 National Historic Preservation Act (NHPA) of 1966 as Amended 

The NHPA of 1966 and its implementing regulations (36 CFR 800) require 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. 

APHIS’ proposed action, a determination of nonregulated status of VCO-01981-5 corn is 

not expected to adversely impact cultural resources on tribal properties. Any farming 

activity that may be taken by farmers on tribal lands would only be conducted at the 

tribe’s request; thus, the tribes would have control over any potential conflict with 

cultural resources on tribal properties.

APHIS’ Preferred Alternative would have no impact on districts, sites, highways, 

structures, or objects listed in or eligible for listing in the National Register of Historic 

Places, nor would it likely cause any loss or destruction of significant scientific, cultural, 

or historical resources. This action is limited to a determination of nonregulated status 

of VCO-01981-5 corn. 

APHIS’ proposed action is not an undertaking that may directly or indirectly cause 

alteration in the character or use of historic properties protected under the NHPA. In 

general, common agricultural activities conducted under this action do not have the 

potential to introduce visual, atmospheric, or noise elements to areas in which they are 

used that could result in effects on the character or use of historic properties. For 

example, there is potential for increased noise on the use and enjoyment of a historic 

property when common agricultural practices, such as the operation of tractors and other 

mechanical equipment, are conducted close to such sites. A built-in mitigating factor 

for this issue is that virtually all of the methods involved would only have temporary 

effects on the audible nature of a site and can be ended at any time to restore the audible 

qualities of such sites to their original condition with no further adverse effects. 

Additionally, these cultivation practices are already being conducted throughout the corn

production regions. The cultivation of VCO-01981-5 corn is not expected to change any 

of these agronomic practices that would result in an adverse impact under the NHPA.

126
8 LIST OF PREPARERS

Biotechnology Regulatory Services

Craig R. Roseland, Ph.D., 

Senior Environmental Protection Specialist 

Environmental Risk Analysis Programs

USDA APHIS

Khamkeo Vongpaseuth, Ph.D.,

Environmental Protection Specialist, 

Environmental Risk Analysis Programs

USDA APHIS

Rebecca L. Stankiewicz Gabel, Ph.D., 

Supervisor, Biotechnology Environmental 

Analysis Branch, Environmental Risk Analysis 

Programs

USDA APHIS

Adam Tulu, Ph.D.,

Environmental Protection Specialist (Intern), 

Environmental Risk Analysis Programs

USDA APHIS

Joanne M. Serrels, MS 

Environmental Protection Specialist 

Environmental Risk Analysis Programs

USDA APHIS

127
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