1 

Pioneer Hi-Bred International, Inc. 

Seed Production Technology (SPT) 

Process DP-32138-1 Corn 

OECD Unique Identifier: 

DP-32138-1 

Final Environmental Assessment 

May 2011 

Agency Contact 

Cindy Eck 

Biotechnology Regulatory Services 

USDA, APHIS 

Riverdale, MD 20737Phone: (301) 734-0667 

Fax: (301) 734-8669 

Cynthia.A.Eck@aphis.usda.gov 

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of 

race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. 

(Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for 

communication of program information (Braille, large print, audiotape, etc.) should contact USDA’S TARGET Center 

at (202) 720–2600 (voice and TDD). 

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326–W, Whitten Building, 1400 

Independence Avenue, SW, Washington, DC 20250–9410 or call (202) 720–5964 (voice and TDD). USDA is an equal 

opportunity provider and employer. 

 

Mention of companies or commercial products in this report does not imply recommendation or endorsement by the 

U.S. Department of Agriculture over others not mentioned. USDA neither guarantees nor warrants the standard of any 

product mentioned. Product names are mentioned solely to report factually on available data and to provide specific 

information. 

 

 

This publication reports research involving pesticides. All uses of pesticides must be registered by appropriate State 

and/or Federal agencies before they can be recommended. 

 

	 	
Table of Contents 

2

List of Tables ...................................................................................................................................4

List of Figures ..................................................................................................................................4

Acronyms and Abbreviations ..........................................................................................................5

I. Purpose and Need ...................................................................................................................7

Regulatory Authority ........................................................................................................................ 7

Regulated Organisms ........................................................................................................................ 8

Petition for Determination of Nonregulated Status: Pioneer 32138-1 Seed Production 

Technology (SPT) Maintainer .......................................................................................................... 8

Purpose of Product ............................................................................................................................ 9

APHIS’ Response to Petition for Nonregulated Status ................................................................ 10

Coordinated Framework Review ................................................................................................... 10

Public Involvement ......................................................................................................................... 10

II. Affected Environment ...........................................................................................................12

Agricultural Production of Corn .................................................................................................... 12

Acreage and Areas of Corn Production ................................................................................. 12

Cropping Practices ................................................................................................................. 12

Seed Production ...................................................................................................................... 13

Organic Farming ..................................................................................................................... 15

Specialty Corn Systems ........................................................................................................... 16

Physical Environment ..................................................................................................................... 17

Water Resources ...................................................................................................................... 17

Soil ........................................................................................................................................... 17

Air Quality ............................................................................................................................... 18

Climate Change ....................................................................................................................... 18

Animal and Plant Communities ..................................................................................................... 19

Animals .................................................................................................................................... 19

Plants ....................................................................................................................................... 20

Biological Diversity ................................................................................................................. 20

Gene Movement ....................................................................................................................... 20

Public Health .................................................................................................................................... 21

Socioeconomic ................................................................................................................................ 22

III. Alternatives ...........................................................................................................................24

No Action: Continuation as a Regulated Article .......................................................................... 24

Preferred Alternative: Determination that DP-32138-1 is No Longer a Regulated Article ...... 24

Alternatives Considered but Rejected from Further Consideration ............................................ 25

Approve the petition in part .................................................................................................... 25

Isolation Distance between DP-32138-1 and Non-GE Corn Production ............................ 26

Requirement of Testing For Event 32138 Corn ..................................................................... 26
Table of Contents 

3

Comparison of Alternatives ............................................................................................................ 26

IV. Environmental Consequences ...............................................................................................28

Scope of the Environmental Analysis ............................................................................................ 28

Other Assumptions .......................................................................................................................... 28

Agricultural Production of Corn ................................................................................................... 29

Organic Production of Corn ................................................................................................... 29

Acreage and Areas of Corn Production ................................................................................. 30

Cropping Practices: Crop Rotation, Tillage, and Pesticide Use .......................................... 30

Seed Production ...................................................................................................................... 32

Organic Farming ..................................................................................................................... 39

Specialty Corn Systems ........................................................................................................... 41

Physical Environment ..................................................................................................................... 41

Water Resources ..................................................................................................................... 41

Soil ........................................................................................................................................... 42

Air Quality ............................................................................................................................... 44

Climate Change ....................................................................................................................... 45

Animal and Plant Communities ..................................................................................................... 46

Animals .................................................................................................................................... 46

Plants ....................................................................................................................................... 47

Biological Diversity ................................................................................................................. 48

Gene Movement ....................................................................................................................... 50

Public Heath ..................................................................................................................................... 52

Human Health ......................................................................................................................... 52

Worker Safety ........................................................................................................................... 54

Animal Feed ............................................................................................................................. 54

Socioeconomic Issues ..................................................................................................................... 56

Domestic Economic Environment at Risk .............................................................................. 56

Trade Economic Environment at Risk .................................................................................... 58

Social Environment at Risk from Seed Production Activities ............................................... 59

Other Cumulative Effects ............................................................................................................... 60

Threatened and Endangered Species ............................................................................................. 60

Consideration of Executive Orders, Standards and Treaties Relating to Environmental 

Impacts ............................................................................................................................................. 62

Impacts on Unique Characteristics of Geographic Areas. ................................................... 63

International Implications....................................................................................................... 64

Compliance with Clean Water Act and Clean Air Act ........................................................... 64

National Historic Preservation Act (NHPA) of 1966 as Amended ....................................... 64

V. References .............................................................................................................................65

VI. Appendix A ...........................................................................................................................77

VII. Appendix B ...........................................................................................................................78

VIII. Appendix C ...........................................................................................................................79
Table of Contents 

4

List of Tables 

Table 1: Issues of potential impacts and consequences of alternatives ....................................... 28 

List of Figures 

Figure 1. Outline of the SPT Process for Producing Hybrid Seed............................................... 35

Figure 2. Production of the 32138 SPT Maintainer Line (Figure 1, Step I) ................................ 36

Figure 3. Visualization of the Red Marker, DsRed2 Expressed by the SPT Cassette ................. 37

Figure 4. Production of the Non-Transgenic Female Sterile Inbred (Step II). ............................ 37
5 

Acronyms and Abbreviations 

32138 SPT maintainer Maize line containing the DP-32138-1 event 

32138 SPT insertion The DNA from plasmid PHP24597 that has been integrated into the 

genome of the 32138 SPT maintainer 

AMS USDA Agricultural Marketing Service 

AOSCA American Organization of Seed Certifying Agencies 

APHIS Animal and Plant Health Inspection Service 

BRS Biotechnology Regulatory Services (within USDA–APHIS) 

Bt Bacillus thuringiensis protein 

CAA Clean Air Act 

CFR Code of Federal Regulations (United States) 

CH4 methane 

CO2 carbon dioxide 

CWA Clean Water Act 

DP-32138-1 Event DP-32138-1, also known as 32138 SPT maintainer 

DsRed2(Alt1) A specific fluorescent marker gene; a variant of Clontech’s DsRed gene 

DsRed2 A specific fluorescent protein expressed by DsRed2(Alt1) gene 

EA environmental assessment 

EO Executive Order 

EPA U.S. Environmental Protection Agency 

FDA U.S. Food and Drug Administration 

FFDCA Federal Food, Drug, and Cosmetic Act 

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act 

FR Federal Register 

GE genetically engineered 

GHG greenhouse gas 

IP identity preservation 

IPCC Intergovernmental Panel on Climate Change 

ISPM International Standard for Phytosanitary Measure

IPPC International Plant Protection Convention

LMO living modified organisms 

Ms45 A specific (dominant) male-fertility gene in maize 

MS45 A specific protein expressed by the Ms45 gene in maize 

ms45 A mutant allele (recessive) of the Ms45 gene in maize 
6

Acronyms and Abbreviations (continued) 

NMFS National Marine Fisheries Service 

NO2 nitrogen dioxide 

N2O nitrous oxide 

NEPA National Environmental Policy Act of 1969 and subsequent 

amendments 

NOP National Organic Program 

NPC new protein consultation 

OSTP Office of Science and Technology Policy 

PRA pest risk analysis 

R&D research and development 

SPT Seed Production Technology 

sq. ft. square feet 

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 

U.S.C. United States Code 

USFWS U.S. Fish and Wildlife Service 

ZM-AA1 A specific α-amylase protein expressed in 32138 SPT maintainer and 

comprised of maize endogenous protein sequences from the Brittle-1 

transit peptide and the ZM-AA1 protein. 
7

I. Purpose and Need 

Regulatory Authority 

“Protecting American agriculture” is the basic charge of the U.S. Department of Agriculture's 

(USDA) Animal and Plant Health Inspection Service (APHIS). APHIS provides leadership in 

ensuring the health and care of plants and animals. The agency improves agricultural 

productivity and competitiveness, and contributes to the national economy and the public health. 

USDA asserts that all methods of agricultural production (conventional, organic, or the use of 

genetically engineered (GE) varieties) can provide benefits to the environment, consumers, and 

farm income. 

Since 1986, the United States government has regulated genetically engineered (GE) organisms 

pursuant to a regulatory framework known as the Coordinated Framework for the Regulation of 

Biotechnology (Coordinated Framework) (51 FR 23302, 57 FR 22984). 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’s Animal and Plant Health Inspection 

Service (APHIS), the Food and Drug Administration (FDA), and the Environmental Protection 

Agency (EPA). 

APHIS is responsible for regulating GE organisms and plants under the plant pest authorities in 

the Plant Protection Act of 2000, as amended (7 USC § 7701 et seq.) to ensure that they do not 

pose a plant pest risk to the environment. 

The FDA regulates GE organisms under the authority of the Federal Food, Drug, and Cosmetic 

Act. The FDA is responsible for ensuring the safety and proper labeling of all plant-derived 

foods and feeds, including those that are genetically engineered. To help developers of food and 

feed derived from GE crops comply with their obligations under Federal food safety laws, FDA 

encourages them to participate in a voluntary consultation process. All food and feed derived 

from GE crops currently on the market in the United States have successfully completed this 

consultation process. The FDA policy statement concerning regulation of products derived from 

new plant varieties, including those genetically engineered, was published in the Federal Register 

on May 29, 1992 (57 FR 22984-23005). Under this policy, FDA uses what is termed a 

consultation process to ensure that human food and animal feed safety issues or other regulatory 

issues (e.g., labeling) are resolved prior to commercial distribution of bioengineered food. 

The EPA regulates plant-incorporated protectants under the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA) and certain biological control organisms under the Toxic Substances 
8

Control Act (TSCA). The 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. 

Regulated Organisms 

The APHIS Biotechnology Regulatory Service’s (BRS) mission is to protect America’s 

agriculture and environment using a dynamic and science-based regulatory framework that 

allows for the safe development and use of GE organisms. 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 Plant 

Protection Act or the regulations at 7 CFR 340. 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 Plant Protection Act when APHIS determines that it is unlikely 

to pose a plant pest risk. 

Petition for Determination of Nonregulated Status: Pioneer 32138-1 Seed Production 

Technology (SPT) Maintainer 

Pioneer Hi-Bred International, Inc. (Pioneer) of Johnston, IA has submitted a petition to APHIS 

seeking a determination that their “Seed Production Technology” (SPT) corn maintainer event 

(hereafter referred to as DP-32138-1 is unlikely to pose a plant pest risk and, therefore, should no 

longer be a regulated article under regulations at 7 CFR Part 340. 

According to Pioneer, DP-32138-1 is engineered to produce male sterile female inbred plants for 

the generation of hybrid corn seed that is non-transgenic (Pioneer 2009). As detailed in the 

petition, the carefully controlled expression of a seed color marker gene and pollen fertility and 

sterility genes allows for the generation of red transgenic seed for seed increase of male sterile 

female inbred lines. The multistep process yields a non-transgenic male-sterile female parent. 

This non-transgenic material can then be used for hybrid seed production (Pioneer 2009). DP32138-1 is currently regulated under 7 CFR part 340. Interstate movements and field trials of 

DP-32138-1 have been conducted under permits issued or notifications acknowledged by 

APHIS. 
9

DP-32138-1 corn is currently regulated under 7 CFR Part 340. Interstate movements, 

importations, and field testing of DP-32138-1 corn have been conducted under notifications 

acknowledged by APHIS. 

DP-32138-1 has been field tested in the U.S. since 2005 as authorized by APHIS. Associated 

notifications acknowledged and permits issued by APHIS are listed in the petition (Pioneer 

2009). The list compiles a total of 11 test sites in diverse regions of the U.S. including the major 

corn growing area of the Midwest and winter nurseries in Hawaii and Puerto Rico. Field tests 

conducted under APHIS oversight allow for evaluation in agricultural settings under 

confinement measures designed to minimize the likelihood of persistence in the environment 

after completion of the field trial. Under confined field trial conditions, data are gathered on 

multiple parameters and used by applicants to evaluate agronomic characteristics and product 

performance. These data are also valuable to APHIS for assessing the potential for a new 

variety to pose a plant pest risk. The evaluated data may be found in the APHIS Plant Pest 

Risk Assessment (USDA-APHIS 2010).

Purpose of Product 

Pioneer seeks determination of nonregulated status of DP-32138-1 corn that was developed to 

facilitate a novel method of seed production to produce male sterile/female inbred plants for the 

generation of hybrid corn seed that is non-transgenic (Pioneer 2009). As detailed in the petition, 

the carefully controlled expression of a seed color marker gene and pollen fertility and sterility 

genes allows for the generation of red transgenic seed for seed increase of male sterile female 

inbred lines that are used for non-transgenic hybrid commercial seed production. Typically, 

detasseling is needed in corn seed production, and confers substantial expense, lower seed yield 

and lower genetic purity. Use of DP-32138-1 would eliminate detasseling and lead to increased 

seed yield and higher genetic purity during seed increase operations. As detailed in the petition, 

the process predictably and reliably results in a commercial product which does not contain the 

DP-32138-1 transgenes (Pioneer 2009). 

Since the 1930’s, corn productivity in the U.S. has been greatly enhanced by the use of hybrid 

corn seed (Sleper and Poehlman 2006). Corn hybrids are characterized by increased resistance to 

diseases and enhanced agronomic characteristics compared with the parental lines (Brewbaker 

1964). The production of hybrid corn seed involves a cross between two inbred lines1

, where the 

pollen from the tassel/male parent is used to fertilize the ear/female parent. Because corn is 

mostly self pollinated (OECD 2003), hybrid corn seed is typically produced by the removal of 

male flowers (tassels) from the female parent plant either mechanically or by hand. These 

methods of detasseling reduce yields and are expensive. Mechanical detasseling may result in up 

to 40 % reduction in seed yield compared to hand detasseling treatments (Wych 1988). 

Additionally, female plants may escape detasseling or develop secondary tassels after manual 

detasseling resulting in female plants that are self-pollinated. Thus, the seed of female inbred 

plants is harvested along with the hybrid seed resulting in reduced genetic purity and lower seed 

yield for the final hybrid variety. 

To overcome the expense, yield reduction and reduced genetic purity associated with detasseling, 

numerous genetic strategies have been attempted to achieve male sterility2

 as alternative 

 

1

 Inbred lines are populations of identical or nearly identical plants used as stocks for the creation of hybrid lines. 

2

 Male sterility is the inability to produce functional pollen. 
10

approaches to detasseling (Skibbe and Schnable 2005). Over 40 genetic elements are associated 

with male sterility; some of which are located on the nuclear chromosomes while others are 

located on the mitochondria chromosomes (Skibbe and Schnable 2005). A major drawback to 

male sterile genetic approaches is the difficulty in generating male sterile inbred lines, because 

no functional pollen is produced in a male sterile plant line. 

APHIS’ Response to Petition for Nonregulated Status 

Under the authority of the plant pest provisions of the Plant Protection Act and 7 CFR Part 340, 

APHIS has issued regulations for the safe development and use of GE organisms. As required 

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

regulated status of GE organisms, including GE plants such as DP-32138-1. When a petition for 

nonregulated status is submitted, APHIS must make a determination if the GE organism is 

unlikely to pose a plant pest risk. If APHIS determines based on its Plant Pest Risk Assessment 

(PPRA) that the genetically engineered organism is unlikely to pose a plant pest risk, the 

genetically engineered organism is no longer subject to the plant pest provisions of the Plant 

Protection Act and 7 CFR part 340. 

APHIS has prepared this environmental assessment (EA) to consider the potential environmental 

effects of an agency determination of nonregulated status consistent with Council of 

Environmental Quality’s (CEQ) regulations implementing NEPA (40 CFR Parts 1500-1508, 7 

CFR 1b, and 7 CFR Part 372), and the USDA and APHIS NEPA implementing regulations and 

procedures. This EA has been prepared in order to specifically evaluate the effects on the quality 

of the human environment3

 that may result from the deregulation of DP-32138-1 corn. 

Coordinated Framework Review 

DP-32138-1 is not designed for human and animal consumption. Discarded parent seed, whether 

it is outdated or discarded from the color sorter, and seed byproducts, such as husks and cobs, 

will be disposed by placing in landfills, composting, or incineration (Pioneer 2009). According 

to Pioneer policy, seed producers will not feed discard corn to animals (Hubbard, 2011 - Public 

Comment on EA for DP-32138-1). However, animals may accidentally gain access to corn 

fields, to discarded corn seed or by-products and therefore may also be subject to regulation by 

FDA. A new protein consultation (NPC) for the DsRed2 protein color marker was submitted to 

FDA on October 11, 2006 with the follow up letter of January 29, 2010 received from FDA 

(Appendix A). The DsRed2 protein is the only non-corn protein in DP-32138-1. A NPC for the 

ZM-AA1 protein, normally found in germinating corn seeds, was submitted to FDA on June 18, 

2009. The FDA considers Pioneer's consultation on ZM-AA1 alpha-amylase protein to be 

complete (Appendix B). Because DP-32138-1 does not contain any GE pesticides or the genetic 

machinery necessary to produce them, or tolerance to herbicides, EPA consultation is not 

required. 

Public Involvement 

APHIS-BRS routinely seeks public comment on draft environmental assessments prepared in 

response to petitions for nonregulated status of GE organisms. APHIS-BRS does this through a 

 

3

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

relationship of people with that environment” (40 CFR §508.14). 
11

notice published in the Federal Register. The issues discussed in this EA were developed by 

considering public concerns as well as issues raised in public comments submitted for other 

environmental assessments of genetically engineered organisms, concerns raised in lawsuits, as 

well as those issues that have been raised 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 genetically engineered plants were addressed to analyze 

the potential environmental impacts of DP-32138-1. 

This EA, the petition submitted by Pioneer, and APHIS’s Plant Pest Risk Assessment, will be 

available for public comment for a period of 60 days (7 CFR § 340.6(d)(2)). Comments received 

by the end of the 60-day period will be reviewed and used to inform APHIS’s determination 

decision of the regulated status of DP-32138-1corn and to assist APHIS in determining whether 

an Environmental Impact Statement is required prior to the determination decision of the 

regulated status of this corn line. 

Issues Considered 

As stated above, the issues considered in this EA were developed based on APHIS’ 

determination to deregulate certain genetically engineered organisms, and for this particular EA, 

the specific deregulation of DP-32138-1 for seed production. 

Management Considerations: 

 Acreage and Areas of Corn Production 

 Cropping Practices 

 Seed Production 

 Organic Farming 

 Specialty Corn Production 

Environmental Considerations: 

 Water Use 

 Soil 

 Air Quality 

 Climate Change 

 Animals 

 Plants 

 Biological Diversity 

 Gene Movement 

Public Health Considerations: 

 Human Health 

 Worker Safety 

Socioeconomic Considerations: 

 Domestic Economic Environment 

 Trade Economic Environment 

 Social Environment 
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II. Affected Environment 

Agricultural Production of Corn 

Acreage and Areas of Corn Production 

Corn (Zea mays L.) is the world's most widely grown cereal, reflecting its ability to adapt to a 

wide range of production environments (Morris 1998). Corn is an annual plant typically grown 

in zones of abundant rainfall and fertile soils (Morris 1998). In the U.S., the moisture levels and 

number of frost-free days required to reach maturity are ideal for corn to be grown within 

temperate regions. Corn varieties having a relative maturity of 100 to 115 days are typically 

grown in the U.S. Corn Belt, which includes Iowa, Illinois, Nebraska, and Minnesota. 

Approximately 50% of all corn grown in the U.S. is from these four states. The Corn Belt also 

includes parts of Indiana, South Dakota, Kansas, Ohio, Wisconsin, and Missouri. 

Approximately 80% of all corn acres grown in the U.S. are within these top ten corn growing 

states; however, corn is grown in all states of the U.S. except Alaska (USDA-NASS 2010a). 

Conventional farming, as defined in this document, includes any farming system where 

synthetic pesticides or fertilizers may be used. This definition of conventional farming includes 

the use of genetically engineered varieties that have been deregulated by APHIS. Conventional 

farming covers a broad scope of farming practices, ranging from farmers who only occasionally 

use synthetic pesticides and fertilizers to those farmers whose harvest depends on regular 

pesticide and fertilizer inputs. 

U.S. corn production for 2009, including production of non-genetically engineered and 

genetically engineered corn varieties, was 13.2 billion bushels from 79.6 million harvested acres 

(USDA-NASS 2009a). In 2007 and 2008, growers harvested 13.0 billion bushels of grain from 

86.56 million acres and 12.1 billion bushels from 78.6 million acres, respectively. Of the total 

corn acres planted in 2009, 85% were GE corn varieties (USDA-NASS 2009a) up from 80% in 

2008 (USDA-NASS 2009a), 73% in 2007 (USDA-NASS 2009a), and 61% in 2006 (USDANASS 2009a). 

Cropping Practices 

Today, growers can choose from hundreds of corn hybrids marketed by companies that produce 

seed including GE varieties (NCGA 2010). Pioneer, the petition applicant, itself offers over 

250 varieties (Pioneer 2010), which in turn implies the total number of corn hybrids available 

industry wide to be approximately 800-1000 since Pioneer has approximately a 30% market 

share (Pioneer 2008). Another estimate of total number of hybrids available for the industry is 

4000 (Monsanto 2010). 

Hybrids differ generally in agronomic characteristics, including disease and pest resistance and 

length of growing period. The optimum planting date for corn, usually between April and May, 

is influenced by factors such as the locality, environmental conditions, seed growing period, and 

seed variety. Harvesting generally occurs from mid-to-late September through November. The 

use of a combine (mechanical harvesting) is the standard practice for grain production (Olson 

and Sander 1988). 
13

Crop rotations (successive planting of different crops on the same land) are used to optimize soil 

nutrition and fertility, and reduce pathogen loads (Hoeft, Nafziger et al. 2000). Crops used in 

rotation with corn vary regionally, but there has been an increase in the number of fields that 

have a corn-to-corn rotation, as opposed to rotation to another crop (Erickson and LowenbergDeBoer 2005). In some areas, the corn-to-corn rotation requires increased levels of fertilizer 

inputs (Sawyer 2007). Insect pests may also increase in corn-to-corn rotations as this system 

may provide a continual host environment for some insects and diseases. However, in a cornsoybean rotation, continuously growing corn for multiple growing seasons can decrease 

populations of soybean pests, such as soybean cyst nematode (Hoeft, Nafziger et al. 2000). 

Corn production typically involves the extensive use of agronomic inputs and technology 

(Rooney and Serna-Saldivar 1987; Shaw 1988; Pollak and White 1995; White and Pollak 

1995), and the main emphasis is placed on obtaining the best yield (Thomas 2007). Depending 

on the region and practices used, corn production includes inputs such as fertilizer (e.g., 

synthetic fertilizers, manure, and compost containing nitrogen and phosphorus) and pesticides 

(synthetic or NOP-approved insecticides, herbicides and fungicides), as well as irrigation. Each 

of these inputs can affect segments of the environment including, but not limited to, waterways 

by increases in nutrient pollution, biodiversity because pesticide inputs cause species changes, 

the water table because of excessive irrigation practices or productive fields because irrigation 

increases salinity (Hoeft, Nafziger et al. 2000). 

Weed control methods differ depending on a number of factors including locality, grower 

resources, and crop trait; the techniques may be direct (e.g. mechanical4

 and chemical5) or 

indirect (e.g. cultural6) (Olson and Sander 1988). Pest control (weeds and insects) in corn 

production is essential in order to obtain good crop yield (Olson and Sander 1988; Hoeft, 

Nafziger et al. 2000). Generally, growers will manage a range of pests simultaneously. 

Therefore, growers will likely chose from a number of techniques to effectively and efficiently 

manage pests in their fields. In 2005, the most prevalent pest management practice was pesticide 

use (USDA-ERS 2005). Ultimately, the management practices utilized by a grower will depend 

on the types of pests in their field, level of infestation, cropping system, type of soil, cost, 

weather, time, and labor. Practices to cope with pests, nutrient needs, and moisture and 

temperature requirements vary regionally. All agricultural production systems, including corn 

production, may affect the surrounding environment. 

Seed Production 

Once a new variety has been developed by the plant breeder, seed providers need to increase 

seed so that commercial fields can be planted by farmers that wish to take advantage of new 

traits. This increase is necessary for all varieties of any plant species, including corn. The 

increase starts with a single seed, a single plant or a handful of seed. In the case of corn, the 

seed of all varieties combined must be able to plant over 90 million acres (USDA-NASS 2009a) 

each year. Since seed companies typically overproduce by 30-40% to assure enough seed for the 

 

4

 Mechanical techniques include tillage and mowing.

5

 Chemical techniques include herbicide application.

6

 Cultural techniques include crop rotation/spot spraying of herbicide/hand removal of weeds. 
14

coming year, about 50-60 million bushels of seed are needed to meet the projected seed needs of 

the next year (Wych 1988). The precise number of bushels of seed needed for a given year is not 

known until all fields have been planted. A number of factors may influence the number of final 

planted acres including: weather, anticipated future commodity prices of corn and competing 

crops, changing goals for the amount of ethanol to be needed in future years, final crop yields in 

the U.S. and other countries that are harvested in the year the seed is produced, changing goals 

of government programs such as the Conservation Reserve Program, etc. (Farnham 2001; 

Nielsen and Thomison 2002; Brock 2007; Schnitkey 2008; Casselman 2010; Ortiz 2010; UK 

2010). 

Corn fields in the U.S. are generally planted with hybrid seed because hybrid vigor allows for 

maximizing grain yield. Beginning in the 1920’s, when the first corn hybrids were introduced 

commercially, and continuing for 40-60 years, hybrids were generally double crosses (Wych 

1988). If seed of double cross hybrids were used to plant 90 million acres, the 50-60 million 

bushels of seed could be harvested from about 500,000 acres since the seed would be harvested 

from female lines that are single cross hybrids. These 500,000 acres would have to be detasseled 

or some other method to control fertile pollen production on these female plants (Wych1988). 

Starting in the late 1950’s, the hybrids transitioned from double crosses to single crosses. 

Currently, single crosses are used almost exclusively (Wych 1988). This transition to single 

crosses occurred because the single crosses out-yielded double crosses and the farmers 

demanded the higher yielding single crosses (Wych1988). To produce 50-60 million bushels of 

single crosses, the seed is harvested from female parents that are inbred lines. Since inbred lines 

produce only about 40-60% of the single cross hybrid, then about one million acres would be 

needed to produce the seed for the 90 million acres of corn grain production. These one million 

acres of seed production (Pioneer 2009) would have to be detasseled or some other method used 

to control fertile pollen production on these female plants. To plant these one million acres, 

about 400,000-500,000 bushels of inbred seed would be needed and would be produced on 

about 10,000-20,000 acres (Pioneer 2009). 

A new hybrid variety could potentially be released in about 2-4 years after the inbred lines have 

been developed. Since inbred lines are maintained and reproduced using self pollination, these 

10,000-20,000 acres do not have to be detasseled. These 10,000-20,000 acres of seed increase of 

inbred lines are subdivided by the estimated 800-4,000 conventional corn hybrids with about 5-

15 acres per variety. To plant these 5-15 acre fields requires only 2-5 bushels of seed, which only 

requires less than 0.1 acres (Pioneer 2009) to produce this seed. To produce enough seed to plant 

these 0.1 acres requires only 2-4 ears from 2-4 plants of the promising inbred line. With good 

planning and use of favorable growing locations, such as winter nurseries in Hawaii and Puerto 

Rico, 2-3 generations of corn can be grown in one calendar year. 

The production of hybrid seed requires stringent control over the pollen sources. The utilization 

of hybrid vigor was practical in corn since the male portion (tassel) of the corn plant was 

completely separate at the top of the plant from the female portion (ear) in the central region of 

the plant. In order to assure that no self pollination occurs and obtain hybrid seed in corn, the 

tassel must be removed (detasseled) from the seed producing plant (female) while allowing 

nearby “male” plants with tassels to pollinate the female plants. Tassels are removed by hand or 

by machine, but both methods are expensive and result in major plant injury with accompanying 

lower seed yields. In 1988, detasseling costs ranged from $100 to $130 per acre (Wych 1988). 

Much of the cost of detasseling is personnel costs. Assuming that detasselers earn 

approximately minimum wages and based on minimum hourly wage rates of $3.35 in 1988 and 
15

$7.25 in 2009 (US-DOL 2010), it can be estimated that 2009 detasseling costs range from $216 

to $281 per acre. Yield reduction due to detasseling has been estimated to range from 1.5% to 

13.5% for hand detasseling and 2%-45% for mechanical detasseling (Wych 1988). To estimate 

cost of yield losses from detasseling, several assumptions can be made. For the production of 

any seed that requires detasseling, contracts are signed with farmers willing to grow the low 

yielding inbred plants along with the challenges of growing corn to exact planting, growing and 

harvesting standards and schedules. In return for these apparent disadvantages of growing seed 

corn, paying premiums and minimums are expected and standard parts of the contract. The 

minimum standards are likely to be equivalent to the returns that would be expected from 

growing conventional corn, which would be based on the average yields in the area and the 

commodity corn price (Wych 1988). For example, the average yield might be 170 bushels with a 

commodity price of $4.00 per acre [yields and prices based on approximate national averages for 

2009 (USDA-NASS 2009a)] making the minimum standard $680 per acre. A 10% yield 

reduction due to detasseling is approximately $68 per acre. From the calculations here, total costs 

of detasseling (cost of detasseling plus yield reduction) may be in the range of $280 to $350 per 

acre. 

To minimize or to overcome impacts and high costs of conventional detasseling, various means 

of inducing male sterility have been explored including cytoplasmic male sterility, genic male 

sterility, and chemically induced male sterility. The cytoplasmic male sterility system, which is 

the only male sterility system that is widely used throughout the industry, tends to have 

problems with reduced restoration to male fertility in the commercial field (Wych 1988). The 

genic male sterility system is complicated, time consuming and expensive (Wych 1988). The 

chemically induced male sterility systems generally had problems with insufficient male sterility 

or with intolerable levels of female sterility (Wych 1988). Research has been conducted over the 

last 20 years to develop useful male sterility systems (Albertsen, Fox et al. 1993; Greenland, 

Bell et al. 1997; Unger, Betz et al. 2001; Unger, Cigan et al. 2002; Havey 2004). Six transgenic 

male sterility systems – Petition Nos. 95-228-01p, 97-148-01p, 97-342-01p, 98-278-01p, 98-

349-01p and 01-206-01p – have been deregulated by APHIS (APHIS-BRS 2010) and none of 

these systems, other than the cytoplasmic male sterility system, have been widely adopted in 

commercial hybrid corn seed production (Pioneer 2009). 

Organic Farming 

Organic farming, as defined in this document, includes any production system that falls under 

the USDA National Organic Program (NOP) definition of organic farming and is a certified 

organic production system. The National Organic Program is administered by USDA’s 

Agricultural Marketing Service (AMS). Organic farming operations, as described by the 

National Organic Program, require organic production operations 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 achieve and document compliance with the 

National Organic Standards, including the prohibition on the use of excluded methods. Excluded 

methods include 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. In 

organic systems, the use of synthetic pesticides, fertilizers, and genetically engineered crops, 

such as DP-32138-1 corn, is strictly limited. 
16

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. Practices growers may use to exclude genetically 

engineered 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. 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 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. Organic certification of a 

production or handling operation is a process claim, not a product claim. 

Certified organic corn acreage is a small percentage of overall corn production. The most 

recently available data show 143,000 acres of organic corn production in 2007. This is 0.17% of 

the total 86.2 million acres of corn planted in 2007 (USDA-ERS 2008). In 2005, 131,000 acres 

of organic corn were planted resulting in a 9% increase in organic corn acreage over the 2 year 

period from 2005 to 2007 (USDA-ERS 2010a). 

Specialty Corn Systems 

The vast majority of corn grown in the U.S. is grown as grain for animal feed, ethanol, and 

industrial uses (USGC 2008). However, approximately 8% of corn grown is specialty corn 

produced for a specific market or use (USGC 2006). Examples of specialty corn include white 

corn, waxy corn, hard endosperm, high oil, non-GE, and organic corn (USGC 2006). The uses 

of these corn varieties include human consumption, food processing (waxy corn) or specialty 

product (white corn, blue corn). These corn varieties are specified by buyers and end-users of 

corn for production, and premiums are paid for delivering a product that meets purity and quality 

standards for the corn variety. Product differentiation and market segmentation in the specialty 

corn industry includes mechanisms to keep track of the grain (traceability) for identity 

preservation (IP) and quality assurance processes (e.g., ISO9001-2000 certification), as well as 

contracts between growers and buyers that specify delivery agreements (Sundstrom, Williams et 

al. 2002). Systems used by specialty corn growers and end-users to maintain identity of the 

production include: 

 Contracts – written agreements detailing responsibilities and duties of both parties, 

including premiums for reaching goals and penalties for failing to attain specifications. 

 Tracking and Traceability Systems – correct labeling of all products (planting seeds and 

harvested material) and testing procedures for identifying and detecting acceptability of 

materials. 

 Quality Assurance Processes – oversight on handling procedures, testing of planting seeds, 

and testing of harvested materials to determine acceptability of use and product 

requirements, and assuring testing procedures are appropriate. 
17

 Closed-Loop Systems – end-user supplies the planting seeds and guarantees to purchase 

final products. May also include that the end-user conduct intermediate procedures such as 

planting, provide oversight during the growing season, harvesting and transportation to 

processing plant. 

 Identity Preservation Systems – using systems of identity preservation that have been shown 

to be successful in the past, such as the seed certification systems conducted by members of 

the Association of Official Seed Certifying Agencies (AOSCA). To maintain the purity of 

the corn product, this production system is based on controlling, tracking and documenting 

each step from seed production to end use (processing plants). 

Physical Environment 

Water Resources 

Corn plants use a substantial amount of water during growth. About 4,000 gallons of water are 

needed to produce 1 bushel of corn (NCGA 2007), and in 2008, 12.1 billion bushels of corn 

were harvested in the U.S (USDA-NASS 2010a). In 2008, about 12.0 million corn acres were 

irrigated, which is approximately 15% of all corn acres planted for grain and the rest of corn 

acreage only receive the ambient rainfall in a given area (USDA-NASS 2008b). Since inbred 

lines are not as vigorous as the hybrid corn plants and the seed of the inbreds is more valuable 

that commercial corn grain, irrigation is used more frequently to lower the risk of drought 

induced seed reduction for growing inbred plants compared to the nearby commercial grain 

fields (Pioneer 2009). 

Soil 

Disturbance and exposure of the top soil surface layer by certain agronomic practices causes 

impacts and may leave crop soils prone to degradation (Hoeft, Nafziger et al. 2000). Two 

environmental impacts of soil degradation are the decline in water quality and the contribution 

to the greenhouse effect (Lal and Bruce 1999). A decline in soil quality and soil resilience7

enhances the greenhouse effect through emissions of radiatively-active gases8 (carbon dioxide 

(CO2), nitrous oxide (N2O)) and depletion of the soil carbon pool (Lal 2003; US-EPA 2010). In 

turn, a decrease in carbon aggregation and sequestration in the soil leads to increased runoff and 

soil erosion. 

Because inbreds are less vigorous than hybrids, greater care is taken in preparing the seed bed to 

provide optimum germinating conditions for the inbred seed. This usually means that the soil is 

tilled more frequently, possibly resulting in more carbon loss and exposing the soil to the 

possibility of increased erosion. In the production of seed corn, when detasseling is required, 

severe damage to the soil structure can occur from the use of detasseler carriers and mechanical 

detasselers under wet soil conditions, resulting in poor water drainage, increased root damage 

and ineffective nutrient uptake resulting in lower seed yields (Kok et al.1996; Daum 1996) 

 

7 Soil resilience is the ability of a soil to restore itself. 

8 Radiatively-active gases are gases that absorb incoming solar radiation or outgoing infrared in turn, affecting the 

temperature of the atmosphere.
18

Indirect effects of detasseling, such as soil compaction, could also impact the subsurface soil 

environment. The corn root system is closely associated with several microbial groups such as 

bacteria, fungi, protozoa, and mites (Bais, Weir et al. 2006) and probably modifies the ecology 

because of these associations. Bacteria typically represent the most abundant microbes in the 

soil followed by fungi (Hoeft, Nafziger et al. 2000). These microbial groups play an important 

and particular role in the ecology of the soil, including nutrient cycling and the availability of 

these nutrients for plant growth. In addition, certain microbial organisms may contribute to the 

protection of the root system against soil pathogens (OECD 2003). 

Air Quality 

Many agricultural activities affect air quality including smoke from agricultural burning, tillage, 

traffic and harvest emissions, pesticide drift from spraying, and nitrous oxide emissions from the 

use of nitrogen fertilizer (Hoeft, Nafziger et al. 2000; Aneja, Schlesinger et al. 2009). These 

agricultural activities individually have potentially adverse environmental impacts on air quality. 

Tillage contributes to the release of greenhouse gases (GHGs) because of the loss of CO2 to the 

atmosphere, and the exposure and oxidation of soil organic matter (Baker, Southard et al. 2005). 

Emissions released from agricultural equipment (e.g., irrigation pumps and tractors) include 

carbon monoxide, nitrogen oxides, reactive organic gases, particulate matter, and sulfur oxides 

(US-EPA 2010). Nitrous oxide may also be released following the use of nitrogen fertilizer (USEPA 2010). Aerial application of pesticides may cause impacts from drift and diffusion. 

Pesticides may volatilize after application to soil or plant surfaces and move following wind 

erosion (Vogel, Majewski et al. 2008). Agriculture, including land-use changes for farming, is 

responsible for an estimated 6 % of all human-induced GHG emissions in the U.S., and N2O 

emissions from agricultural soil management are a large part of this, 68 % of all U.S. N2O 

emissions (US-EPA 2010). 

Climate Change 

Climate change is possibly interrelated with agriculture in several relevant ways. Production of 

agricultural commodities is one of the many human activities that could contribute greenhouse 

gases to the air (Iserman 1993; Hoeft, Nafziger et al. 2000; Aneja, Schlesinger et al. 2009). First, 

this may occur through the combustion of fossil fuels to run farm equipment, the use of 

fertilizers, or the decomposition of agricultural waste products including crop residues and 

animal wastes. Second, the classes of crops planted are relevant to climate change, whether 

trees, grasses or field crops (Cole, Duxbury et al. 1997; Freibauer, Rounsevell et al. 2004). The 

location and the soil types in which they are planted also affect production of greenhouse gases 

(Flessa, Wild et al. 1998; Kamp, Steindl et al. 2001). Third, climate change itself may force 

changes to agricultural practices by extending the ranges of weeds and pests of agriculture (IPCC 

2007). The influences that GE agricultural organisms may have on global climate change are 

unclear. Many of the indirect effects of these organisms will be determined by the traits 

engineered into organisms and the management strategies used in the production of these 

organisms. APHIS will continue to monitor developments that may lead to possible changes in 

the conventional production system likely to result from GE products brought to APHIS for 

approval. Some of the crops submitted by developers may clearly promote changes that may 

have impacts on greenhouse gases or the climate. 

Climate changing greenhouse gas production will not be significant unless large amounts of crop 

plantings produce changes in measureable concentrations. The contribution of agriculture to 
19

climate change is largely 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. A recent Intergovernmental Panel on Climate Change (IPCC) forecast (IPCC 2007) 

for aggregate North American impacts on agriculture from climate change actually projects yield 

increases of 5-20% for this century. The IPCC report notes, however, that certain regions of the 

U.S. will be more heavily impacted because water resources may be substantially reduced. While 

agricultural impacts on existing crops may be significant, North American production is 

expected to adapt with improved cultivars and responsive farm management (IPCC 2007). 

Animal and Plant Communities 

Animals 

Corn fields have been known to be visited by birds, deer and small mammals (e.g. deer mice), 

and other types of wildlife species. Although many birds visit row-crop fields such as corn, 

numbers are low and few nest there (Patterson and Best 1996). The red-winged blackbird 

(Agelaius phoeniceus) is the most abundant bird in North America; they are often initially 

attracted to corn fields to feed on insect pests but then feed on the corn. Annually, this bird 

destroys over 360,000 tons of field corn and substantial amounts of sweet corn (Dolbeer 1990); 

other abundant species of birds that forage and/or nest on and around corn include the horned 

lark (Eremophila alpestris), the brown-headed cowbird (Molothrus ater), and the vesper 

sparrow (Pooecetes gramineus) (Patterson and Best 1996). 

Deer, such as the white-tailed (Odocoileus virginianus), find field corn attractive because it 

functions both as food and cover throughout the latter half of the growing season (Vercauteren 

and Hygnstrom 1993). Deer can significantly damage or completely destroy small corn fields 

that are surrounded by woody or brushy areas; however, deer damage to large corn fields is 

often limited to a few rows closest to the wooded areas (Neilsen 2005). The deer mouse 

(Peromyscus maniculatus) is the most common small mammal in almost any agricultural field 

(Stallman and Best 1996; Sterner, Petersen et al. 2003). The deer mouse feeds on a wide variety 

of plant and animal matter depending on availability, but primarily feeds on seeds and insects. 

The deer mouse has been considered beneficial in agroecosystems because it consumes both 

weed and pest insect species. The meadow vole (Microtus pennsylvanicus) feeds primarily on 

fresh grass, sedges, and herbs, but also on seeds and grains (Sterner, Petersen et al. 2003). The 

meadow vole may also be considered beneficial for its role in the consumption of weeds, but 

can be a significant agricultural pest where abundant as they rely on cover absent from tilled 

agriculture. The lined ground squirrel (Spermophilus tridecemlineatus) feeds primarily on seeds 

of weeds and available crops, such as corn and wheat (Sterner, Petersen et al. 2003). This 

species has the potential to damage agricultural crops, although this ground squirrel can also be 

considered beneficial when eating pest insects, such as grasshoppers and cutworms. 

Although many of the invertebrate organisms found in corn-producing areas are considered 

pests, such as the European corn borer (Ostrinia nubilalis) and the corn rootworm (Diabrotica 

spp.), many others are considered beneficial (Hoeft, Nafziger et al. 2000). Numerous insects and 

related arthropods perform valuable functions: they pollinate plants, contribute to the decay of 

organic matter, cycle soil nutrients, and attack other insects and mites that are considered to be 

pests. 
20

Plants 

The landscape surrounding a corn field varies depending on the region. In certain areas, corn 

fields may be bordered by other corn (or any other crop); fields may also be surrounded by 

woodland and/or pasture/grassland areas. Therefore, the types of weeds in and around a corn 

field depend on the immediate area in which the corn is planted. Those weed species present 

will also vary depending on the geographic region where the corn is planted. Weeds compete 

with crops for water, nutrients, light, and other growth factors. Each year in the U.S., corn yields 

are threatened by more than 200 weed species (Heap 2008). Weed species such as giant foxtail 

and barnyardgrass have been shown to reduce corn yields by up to 13 and 35%, respectively 

(Bosnic and Swanson 1997; Fausay, Kells et al. 1997). Common weeds that cause problems in 

corn fields include velvetleaf, common cocklebur, common lambsquarters (annuals) and 

quackgrass and Johnsongrass (perennials) (Hoeft, Nafziger et al. 2000). 

Biological Diversity 

Species diversity and abundance in corn agro-ecosystems may differ between the three corn 

production methods: conventional with GE varieties, conventional with non-GE varieties, and 

organic. Many studies over the last 10 years have investigated the differences in biological 

diversity and abundance between GE and non-GE fields, particularly those GE crops that are 

resistant to insects (e.g., Bt crops) or herbicides (e.g., glyphosate-tolerant or glufosinate-tolerant 

crops.) Different studies have indicated potential decreases in biological diversity or abundance 

due to GE crops, or the presence of a pesticidal protein in some GE crops (Bt) (e.g., (Hansen 

Jesse and Obrycki 2000; Ponsard, Gutierrez et al. 2002; Pilcher, Rice et al. 2005). Some studies 

investigating decreases in weed populations following the use of herbicides and herbicidetolerant crops have observed decreases in animal populations using the weeds as a food or 

refuge source. Herbicide inputs in some cases may reduce overall biological diversity in farmed 

fields (Marshall, Brown et al. 2003). Other studies of GE crops, such as Bt corn, when 

compared to non-GE crops sprayed with insecticides demonstrate that GE crops do not cause 

any changes in arthropod abundance or diversity (e.g., (Bitzer, Rice et al. 2005; Torres and 

Ruberson 2005; Romeis, Meissle et al. 2006; Marvier, McCreedy et al. 2007; Chen, Zhao et al. 

2008; Wolfenbarger, Naranjo et al. 2008)). Some reports show that GE crops may even 

increase biological diversity (e.g., (Romeis, Meissle et al. 2006; Marvier, McCreedy et al. 

2007)) in agro-ecosystems. Herbicide-tolerant corn, when compared to non-GE corn 

production, may not result in changes in arthropod abundance and may even increase species 

diversity during different times of the year (e.g., (Brooks, Bohan et al. 2003; Haughton, 

Champion et al. 2003; Hawes, Haughton et al. 2003; Roy, Bohan et al. 2003; Wolfenbarger, 

Naranjo et al. 2008)). Since biological diversity can be defined and measured in many ways, 

APHIS considers determining the level of biological diversity in any crop to be complex and 

hard to achieve concurrence. Another difficulty with biodiversity studies is separating expected 

impacts from indirect impacts. For example, reductions of biological control organisms are 

seen in some Bt-expressing GE crops, but are caused by reduction of the pest host population 

following transgenic pesticide expression in the transformed crop plant. 

Gene Movement 

Corn plants are pollinated through wind movement of pollen to other receptive corn plants. In 

the U.S., there are no other species that can be pollinated by corn pollen without human 

intervention (e.g., manually forcing reproduction in the laboratory) (USDA-APHIS 2010). 
21

Thus, the public concern surrounding gene movement for GE corn is between GE and non-GE 

corn plants. Of the total corn acres planted in 2009, 85% were GE corn varieties (USDA-NASS 

2009a). Specialty corn, those with traits of particular interest to various markets such as blue 

corn, waxy corn or organic corn, are typically grown with various management practices that 

intend to limit corn pollen from reaching the specialty corn crop during the period of time that 

the specialty corn crop is receptive to pollen. For example, the NOP has requirements for 

organic plans to address pollen flow from GE crops (Kuepper 2002; Krueger 2007; Kuepper, 

Born et al. 2007). The Association of Official Seed Certifying Agencies (AOSCA) also has 

information for specialty corn crops, and a protocol for growing non-GE corn (AOSCA 2008). 

There is a price premium associated with growing these types of specialty crops in conjunction 

with the extra regimens in place to maximize the purity of these specialty crops. For example, in 

2007, conventional corn averaged $4.19/bushel (USDA-NASS 2010b), whereas organic corn 

averaged $7.08/bushel (USDA-NASS 2010c). 

A recent paper reviewed studies investigating gene flow and cross-fertilization studies in corn 

grain production fields, and using the data from these studies recommended 50m (approx. 164ft) 

as the distance needed to isolate GE corn from non-GE corn (Sanvido, Widmer et al. 2008). The 

authors limited their analysis to studies that confirmed fertilization in the non-GE corn plants, 

and excluded studies on pollen dispersal (e.g., (Raynor, Ogden et al. 1972; Di Giovanni, Kevan 

et al. 1995; Aylor, Schultes et al. 2003)) that only measured pollen flow, because pollen flow 

does not necessarily result in fertilization. Successful cross-fertilization requires many different 

biological and physical factors, such as synchrony of flowering between corn fields, viability of 

pollen, and presence of physical barriers, and thus pollen dispersal is not equivalent to cross 

fertilization. Sandivo et al. (2008) analyzed existing studies and found that the cross-fertilization 

rate in non-GE corn typically remained below 0.5% at this distance. This result was validated 

when large scale studies were analyzed for cross-fertilization events (e.g. (Henry, Morgan et al. 

2003; Weber, Bringezu et al. 2007). 

However, there are studies that refute the success of distance as an isolation strategy. Jones and 

Brooks (1950) found cross-fertilization to be as high as 2.5 % at 660ft, which is the isolation 

distance used by AOSCA to isolate corn fields for seed production (AOSCA 2004). One 

potential reason for the discrepancy between this study and many other gene flow studies in 

corn may be due to the type of corn used in the Jones and Brooks study. Jones and Brooks 

(1950) investigated the appropriate isolation distance for seed production in open-pollinated 

varieties, and not in hybrid varieties. Due the biology of open-pollinated varieties, these types of 

plants may be more receptive to pollen over a longer period of time than hybrid corn plants 

(Sanvido, Widmer et al. 2008), allowing for a greater chance of pollination events. Thus the 

results from Jones and Brooks (1950) may be an overestimation of cross-fertilization potential 

for hybrid corn plants. 

Public Health 

Public health concerns surrounding GE field corn, like DP-32138-1 corn, focus primarily on 

human and animal consumption. Non-GE corn varieties, both those developed for conventional 

use and for use in organic production systems, do not require routine evaluation by any 

regulatory agency in the U.S. for food or feed safety prior to release in the market. Under the 

Federal Food, Drug, and Cosmetic Act (FFDCA), it is the responsibility of food and feed 

manufacturers to ensure that the products they market are safe and properly labeled. Food and 

feed derived from DP-32138-1 must be in compliance with all applicable legal and regulatory 
22

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, applicants who 

wish to commercialize a GE variety that will be included in the food supply invariably complete 

a consultation with the FDA. In a 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; FDA evaluates the submission and 

responds to the developer by letter (US-FDA 2010). 

Socioeconomic 

The last three decades have been marked by significant transition in the seed industry 

(Fernandez-Cornejo 2004). Before the 1970’s, seed development occurred in the public domain. 

Most private seed companies focused on cleaning, handling, storing packaging, and selling seed 

(Fernandez-Cornejo 2004). However, following the passage of the 1970 Plant Variety Protection 

Act, more than 50 seed companies were acquired by pharmaceutical, petrochemical, and food 

firms (Fernandez-Cornejo 2004). Mergers and acquisitions created a new seed industry structure 

and, by the early 1980s, several international firms were among the top seed sellers worldwide 

(Fernandez-Cornejo 2004). The seed company can be viewed in terms of different functions 

including plant breeding research and development (R&D), seed production, seed conditioning, 

and seed marketing and distribution. The high costs associated with large-scale R&D limit this 

activity to Federal Government agencies, land-grant colleges and universities, and a small 

number of large companies. Given the size of their R&D investments, these plant breeders play a 

central role in managing the entire production, distribution, and marketing processes in the seed 

industry (Fernandez-Cornejo 2004). In 1999-2002, approximately 300 firms were involved with 

seed corn production with the top five companies having 64% market share, the next 10 

companies having an additional 16% market share, and the rest of the companies having the 

remaining 20% market share (Kalaitzandonakes and Magnier 2004). 

The top five companies involved in seed production are national or multinational companies with 

their own R&D departments developing their own genetics and their own production, processing 

and distribution facilities. The next 10 largest companies are regional with a dependence on 

foundation seed firms and university developed lines in addition to their own proprietary 

genetics along with their own production and distribution facilities. The remaining smaller firms 

depend almost solely on purchased genetics and others for production and concentrate on 

distribution (Kalaitzandonakes and Magnier 2004). These smaller seed companies with a 

marketable seed product typically contract out the production and multiplication processes to 

farmers, farmers’ associations, and private firms such as Illinois Crop Improvement Association 

(www.ilcrop.com), Indiana Crop Improvement Association (http://www.indianacrop.org/), and 

Iowa Crop Improvement Association (http://www.agron.iastate.edu/ICIA). 

In all cases, seed companies closely manage the production of seed by contract growers. Seed 

companies want to ensure that the desirable plant characteristics are carried through to 

subsequent generations and to prevent problems that could affect the quality of the product 

(Fernandez-Cornejo 2004). After harvesting certified seed, the seed is conditioned, which 

includes the drying, cleaning, and sorting of seed. Seeds are also treated with insecticides and 

fungicides and packaged for distribution and sale to farmers (Fernandez-Cornejo 2004). Large 

seed companies play a more direct role in assuring their seed meets at least the minimum 

standards for certified seed as well as in marketing and distributing their end product to regional, 
23

national, and international markets. Many companies also license or outsource marketing and 

distribution to private firms and individuals to improve access to local markets (FernandezCornejo 2004). 

Technical developments in the genetic engineering of plants has been one of the prime 

motivations for the consolidation of the seed corn companies (Kalaitzandonakes and Hayenga 

1999; Fernandez-Cornejo 2004; Kalaitzandonakes and Magnier 2004) with high biotechnology 

regulatory/compliance costs being the major reason for limiting the development and marketing 

of new biotech corn varieties to the large national/multinational companies (Fulton and 

Giannakas 2001; Kalaitzandonakes and Magnier 2004). The greater the regulatory requirements 

in an industry, the more concentrated the industry is expected to be (Fulton and Giannakas 2001) 

with accumulating evidence suggesting that biotechnology compliance costs have increased over 

time (Kalaitzandonakes, Alston et al. 2007). 

In the production of hybrid seed corn, the task that is one of the most difficult but essential to the 

overall success is the detasseling of the corn. Manual detasseling of corn is a physically 

demanding job consisting of pulling tassels out of the top of thousands of tall corn plants by each 

detasseler each day. Detasseling operations are conducted under challenging conditions, such as 

those environmental conditions that persist in July in the U.S. Midwest. Detasseling is a 

temporary job lasting only one to four weeks in mid-summer. The job is time sensitive because 

tassels need to be pulled within a day of emergence before any pollen is released; a high level of 

flexibility for the task is required because the emergence of tassels depends on the weather. Hot 

humid weather speeds up the emergence of tassels by one to more weeks and cold wet weather 

slows down the emergence of tassels by one or more weeks. Thousands of people are needed to 

complete the operation in timely basis. Because of the short duration and physical demands of 

the job, the detasseling operation mainly attracts high school students during the summer break. 

Thousands of high school students are hired for detasseling each year (Byron 2002; Pioneer 

2007; Gustafson 2008; Holloway 2010; Schernikau 2010). 

 

There are many challenges for the farmers whose land is contracted to grow the low yielding 

inbred plants including growing corn to meet exacting planting, growing and harvesting 

standards and schedules. Additionally, pay premiums and minimums are standard parts of the 

contract. The minimum standards are likely to be equivalent to the returns that would be 

expected from growing conventional corn, and based on the average yields in the area and the 

commodity corn price. For example, the average yield might be 170 bushels with a commodity 

price of $4.00 per acre making the minimum standard $680 per acre. These contract conditions 

also require that the farmers need to accept the large ruts that are left by detasseling machines 

used in muddy conditions. These ruts destroy soil structure, increase tillage requirements, 

increase erosion, result in major yield reduction in the corn crop and possibly in the crop the 

following year as well, and result in damage to harvesting and tillage machinery (Daum 1996; 

Kok, Taylor et al. 1996; Gelderman 2009; Tilghman 2009; Roegge 2010). 

For the company that wants to produce and sell the hybrid seed corn at a profit, detasseling is an 

expensive operation whether it is manual or mechanical. Mechanical detasselers reduce the need 

for manual (human) detasselers, but they tend to reduce yields even more than manual 

detasseling operations and manual detasseling is still required to completely finish the job (Wych 

1988). 
24

The United States is the largest seed market worldwide, followed by China and Japan 

(Fernandez-Cornejo 2004). Seed expenditures by U.S. farmers rose from about $500 million per 

year in 1960 to nearly $7 billion in 1997 (Fernandez-Cornejo 2004). The United States is a net 

exporter of seed. In 1996, the U.S. seed trade surplus was $384 million: $698 million in seed 

exports were mainly sent to Mexico, Canada, Italy, Japan, and Argentina. About $314 million in 

seed imports, were received mainly from Canada, Chile, the Netherlands, and China (FernandezCornejo 2004). 

III. Alternatives 

This document analyzes the potential environmental consequences of a determination of 

nonregulated status of DP-32138-1 corn. To respond favorably to a petition for nonregulated 

status, APHIS must determine that DP-32138-1 corn is unlikely to pose a plant pest risk. Based 

on its risk assessment APHIS has concluded that DP-32138-1 corn is unlikely to pose a plant 

pest risk (USDA-APHIS 2010). Therefore APHIS must determine that DP-32138-1 corn is no 

longer subject to 7 CFR part 340 or the plant pest provisions of the Plant Protection Act. 

Two alternatives will be evaluated in this EA: (1) no action and (2) determination of 

nonregulated status of DP-32138-1 corn. APHIS has assessed the potential for environmental 

impacts for each alternative in the “Environmental Consequences” section

No Action: Continuation as a Regulated Article 

Under the No Action Alternative, APHIS would deny the petition. DP-32138-1 corn and 

progeny derived from DP-32138-1 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 DP-32138-1 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 DP-32138-1 corn. 

This alternative is not the Preferred Alternative because APHIS has concluded through a Plant 

Pest Risk Assessment that DP-32138-1 corn is unlikely to pose a plant pest risk (USDA-APHIS 

2010). 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. 

Preferred Alternative: Determination that DP-32138-1 is No Longer a Regulated 

Article 

Under this alternative, DP-32138-1 corn and progeny derived from them would no longer be 

regulated articles under the regulations at 7 CFR Part 340. DP-32138-1 corn is unlikely to pose 

a plant pest risk (USDA-APHIS 2010). Permits issued or notifications acknowledged by APHIS 

would no longer be required for introductions of DP-32138-1 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 DP-32138-1 corn are unlikely to pose a plant pest risk, a determination of nonregulated 

status of DP-32138-1 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. Under this alternative, growers may have future access to DP-32138-1 
25

corn and progeny derived from this event if the developer decides to commercialize DP-32138-1 

corn. 

Alternatives Considered but Rejected from Further Consideration 

APHIS assembled a list of alternatives that might be considered for DP-32138-1 corn. 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 DP-32138-1 corn. Based on this evaluation, APHIS rejected several alternatives. 

These alternatives are discussed briefly below along with the specific reasons for rejecting each. 

Prohibit any DP-32138-1 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 DP-32138-1, including denying any 

permits associated with the field testing. APHIS determined that this alternative is not 

appropriate given that APHIS has concluded that DP-32138-1 is unlikely to pose a plant pest 

risk(USDA-APHIS 2010). 

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) (see 7 U.S. C. §7701(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 our Plant Pest Risk Assessment (USDA-APHIS 2010) and the scientific data 

evaluated therein, APHIS concluded that DP-32138-1 are unlikely to pose a plant pest risk. 

Accordingly, there is no basis in science for prohibiting the release of DP-32138-1.

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 DP-32138-1 corn is unlikely to pose a plant pest risk, there is no 
26

regulatory basis under the plant pest provisions of the Plant Protection Act for considering 

approval of the petition only in part. 

Isolation Distance between DP-32138-1 and Non-GE Corn Production 

In response to public concerns of gene movement between GE and non-GE plants, APHIS 

considered requiring an isolation distance of DP-32138-1 corn and non-GE corn production. 

However, because APHIS has concluded that DP-32138-1 corn is unlikely to pose a plant 

pest risk (USDA-APHIS 2010), an alternative based on requiring isolation distances would be 

inconsistent 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 

DP-32138-1 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 DP-32138-1 corn, there are no geographic differences associated 

with any identifiable plant pest risks for DP-32138-1 corn (USDA-APHIS 2010). This 

alternative was rejected and not analyzed in detail because APHIS has concluded that DP-32138-

1 corn 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. Nevertheless, APHIS is not expecting significant effects. 

However, individuals might choose on their own to geographically isolate their non-GE corn 

production systems from DP-32138-1 corn or to use isolation distances and other management 

practices to minimize gene movement between corn fields. Information to assist growers in 

making informed management decisions for DP-32138-1 corn is available from Association of 

Official Seed Certifying Agencies (AOSCA 2010). 

Requirement of Testing For Event 32138 Corn 

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 DP-32138-1 corn does not pose a plant pest risk 

(USDA-APHIS 2010), 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 the 

biotechnology regulatory policies embodied in the Coordinated Framework. Therefore, 

imposing such a requirement for DP-32138-1 corn would not meet APHIS’ purpose and need to 

respond appropriately to the petition in accordance with its regulatory authorities. 

Comparison of Alternatives 

Table 1, below, briefly summarizes the results for each of the issues raised in the Environmental 
27

Consequences (Section IV) by each of the alternatives described in the Alternatives section 

(Section III). 

Table 1. 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 

No Yes 

Unlikely to Pose a Plant 

Pest Risk 

Satisfied through use 

of regulated field 

trials 

Satisfied—plant pest risk assessment 

(USDA-APHIS 2010) 

Management Practices

Acreage and Areas of 

Corn Production Unchanged Unchanged 

Cropping Practices Unchanged Unchanged 

Pesticide Use Unchanged Unchanged 

Seed Corn Production Unchanged Minimal - may decrease need for seed 

corn acreage due to increased yields 

efficiency

Organic Farming Unchanged Unchanged 

Impact to Specialty Corn Unchanged Unchanged

Environment

Water use Unchanged Unchanged 

Soil Unchanged Unchanged 

Air Quality Unchanged Unchanged 

Climate Change Unchanged Unchanged 

Animals Unchanged Unchanged 

Plants Unchanged Unchanged 

Biological Diversity Minimal Minimal 

Gene Movement Minimal Minimal 

Human and Animal Health

Public Health: Risk to 

Human Health 

Unchanged Unchanged 

Public Health: Risk to 

Worker Safety 

Minimal – detasseling 

carries some risk to 

workers

Minimal – fewer safety risks with less 

detasseling 

Public Health: Risk to 

Animal Feed 

Unchanged Unchanged 

Socioeconomic 

Domestic Economic 

Environment 

 Unchanged Minimal – seed producers save 4% of 

retail sales price; growers – possible small 

seed cost decrease 

 Unchanged – immeasurably small impact 

on cost of commodity corn 

Trade Economic 

Environment 

 Unchanged Unchanged 
28

Attribute/Measure Alternative A: No 

Action 

Alternative B: Determination of 

Nonregulated Status 

Social Environment Unchanged Minimal – fewer part time detasselers 

hired for summer work 

Other Regulatory Approvals

U. S. Completed new protein 

consultations with FDA

Completed new protein consultations 

with FDA 

Compliance with Other Laws

CWA, CAA. EOs Fully compliant Fully compliant 

IV. 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 DP-32138-1 corn does not pose a plant pest risk. 

Potential environmental impacts from the No Action Alternative and the Preferred Alternative 

for DP-32138-1 are described in detail throughout this section. A cumulative effects analysis is 

also included for each environmental issue. Certain aspects of this product and its cultivation 

would be no different between the alternatives: those are described below. 

Scope of the Environmental Analysis 

Although the preferred alternative would allow for new plantings of DP-32138-1 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 the 

National Agricultural Statistics Service (NASS) 2007 Census of Agriculture to determine where 

corn is produced in the United States (USDA-NASS 2010d). Corn grain was produced in all 

states except for Alaska. 

The scope of possible impacts is limited in some ways by the relatively small area of potential 

use. DP-32138-1 lines containing transgenes only have utility in seed production and are not 

intended to be a commercial product to be used to plant conventional corn acres (Pioneer 2009). 

The total acreage of DP-32138-1 planted in the U.S. each year under close supervision is 

expected to be less than 5,000 acres (Pioneer 2009). If the DP-32138-1 is licensed to third parties 

and adopted across the entire U.S. seed industry, the total acreage is not expected to exceed 

20,000 acres each year (Pioneer 2009). 

Other Assumptions 

The environmental consequences of the different alternatives described above will be analyzed 

under the assumption that seed producers who produce corn seed using DP-32138-1 corn and 

farmers who produce conventional corn or corn using organic methods are using reasonable, 

commonly accepted best management practices for their chosen system and varieties during 

agricultural corn production. However, APHIS recognizes that not all farmers follow these best 

management practices for corn. Thus, the analyses of the environmental effects will also include 

the assumption that some farmers do not follow these best management practices. 
29

Agricultural Production of Corn 

One of APHIS’ missions is to improve American agricultural productivity. Best management 

practices, such as planting dates, seeding rates, and harvest times are commonly accepted, 

practical ways to grow corn, regardless of whether the corn farmer is using conventional 

practices with non-GE or GE varieties, or organic practices. These well-established, widelypracticed means to produce corn can be obtained through local Cooperative Extension Service 

offices and their respective websites (NSFC-IPM 2010). 

GE and non-GE corn varieties are continually under development. From 2004 to 2009, the corn 

acreage ranged from a low of 78.3 million acres planted in 2006 to a high of 93.5 million acres 

planted in 2007. Most of the corn acreage in the U.S. is planted to GE varieties. Of the 86.3 

million acres of corn planted in the U.S. in 2009, 85% of the acreage was planted with GE 

varieties (USDA-NASS 2009a). Based upon these trends, conventional production practices that 

use GE varieties will likely continue to dominate in terms of acreage, or perhaps increase in 

acreage, with or without a determination of nonregulated status of DP-32138-1. 

Organic Production of Corn

APHIS recognizes that producers of non-GE corn, particularly producers who sell their products 

to markets sensitive to genetically engineered traits (e.g. organic or some export markets) can be 

reasonably assumed to be using practices on their farm to protect their crop from unwanted 

substances and maintain their price premium. For example, the National Organic Program 

(NOP) has recognized the feasibility of protecting organically-produced crops, and the 

investment farmers put into their production practices, by requiring that organic production plans 

include practical methods to protect organically-produced crops. 

“Organic crops must be protected from contamination by prohibited substances used on 

adjoining lands (for example, drifting pesticides, fertilizer-laden runoff water, and pollen drift 

from genetically engineered...)” (NCAT 2003). 

Typically, growers use more than one method under organic practices 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, as well as formal 

communications between neighboring farms (NCAT 2003). The organic plan used as the basis 

for organic certification should include a description of practices used to prevent or reduce the 

likelihood of unwanted substances, like GE pollen or seed, at each step in the farming operation, 

such as planting, harvesting, storing and transporting the crop (Riddle 2004; Krueger 2007; 

Kuepper, Born et al. 2007). Organic plans should also include how the risk of GE pollen or comingling of seed will be monitored (Kuepper, Born et al. 2007). Farmers using organic methods 

are requested to let neighboring farmers know that they are using organic production practices 

and request that the neighbors also help the organic farmer reduce contamination events (NCAT 

2003; Krueger 2007). Recommended organic production practices for field corn are also readily 

available (Kuepper 2002). Thus, commonly used production practices for corn, and the practical 

methods typically used by organic corn farmers to protect their crop and maximize their profits 

and price premiums from corn under organic production, currently provide many measures that 

greatly reduce the likelihood of accidental gene flow between DP-32138-1 corn and non-GE 

corn fields. APHIS will use the assumption that farmers are already using, or have the ability to 

use, these common, reasonable practices as its baseline for the analyses of the following 

alternatives below. 
30

Acreage and Areas of Corn Production 

No Action: Acreage and Areas of Corn Production 

The amount of GE corn planted in conventional systems in the U.S. is increasing. Since 2000 

when 25% of the total corn acreage was devoted to GE varieties, the share of total corn acres 

devoted to GE corn varieties has risen each year to the present 85% level in 2009 (USDA-NASS 

2009a). 

Conventional corn production with GE varieties will likely continue to increase without a 

determination of nonregulated status of DP-32138-1 under the No Action Alternative, based 

on current acreage trends. Seed for currently available conventional and GE varieties will 

remain the same under the No Action Alternative, except progeny of DP-32138-1 will be 

unavailable. Corn is currently produced commercially in 49 states, excluding only Alaska 

according to the 2007 Census of Agriculture (USDA-NASS 2009b) and under the No Action 

Alternative, this range of production will be unchanged. 

Preferred Alternative: Acreage and Areas of Corn Production 

In 2009, GE corn was planted on 85% of all corn acres currently in production in the U.S., and 

the use of GE corn has been steadily increasing over the last 10 years (USDA-NASS 2009a). 

Most corn is planted in fields that have been in crop production for many years. A 

determination of nonregulated status of DP-32138-1under the Preferred Alternative is not 

expected to alter the range of corn cultivation as the new GE trait (DP-32138-1) does not change 

the growth habits compared to conventional varieties (USDA-APHIS 2010). Additionally, 

because DP-32138-1 is a technique for more efficiently producing seed that will be used to plant 

conventional corn production acres without introducing new transgenes to these production acres, 

even widespread use of DP-32138-1 will have no significant effect on increasing or decreasing 

the use of GE corn or on total corn production acreage. 

Thus, under the preferred alternative, a determination of nonregulated status of DP-32138-1 

would not increase corn production, either by its availability alone or accompanied by other 

factors, or cause an increase in overall GE corn acreage. Impacts would be similar to the No 

Action Alternative. 

Cumulative Effects: Acreage and Areas of Corn Production 

Cumulative effects of a determination of nonregulated status of DP-32138-1 are unlikely. 

Neither the No Action Alternative nor a determination of nonregulated status of DP-32138-1 

will directly cause an increase in agricultural acreage devoted to corn production, or those corn 

acres devoted to GE corn cultivation. DP-32138-1 will also not change cultivation areas for 

corn production in the U.S. There are no anticipated changes to the availability of GE and nonGE corn varieties on the market under either alternative. 

Cropping Practices: Crop Rotation, Tillage, and Pesticide Use 

The current economics of corn production are driving the change or perceived change in crop 

rotation practices (such as corn-to-corn cropping, Erickson and Lowenberg-DeBoer, 2005). 

Growers make choices to plant certain corn varieties and use certain crop rotation practices 

based on factors such as yield, weed and disease pressures, cost of seed and other inputs, 
31

technology fees, human safety, potential for crop injury, and ease and flexibility of the 

production system (Olson and Sander 1988; Giannessi 2005). Therefore, when taking into 

account these factors, growers will ultimately base their choice of inputs and agronomic practices 

on individual wants and needs. There may be more tillage and use of pesticides involved with the 

production of seed corn than with commercial corn grain. The low vigor of seed and plants of 

inbred lines compared to hybrid corn generally means a better seed bed is needed (generally 

requiring more tillage) along with the protection from diseases and insects provided by pesticide 

used on the seed and the plants (Pioneer 2009). 

No Action: Cropping Practices: Crop Rotation, Tillage, Production, and Pesticide Use 

Producing seed corn requires taking into account the crop rotation on the farm on which the 

seed production is taking place as well as the crop rotations on surrounding farms. Adequate 

isolation must be assured to maintain high genetic purity. Corn after corn rotation is 

discouraged to help avoid the possibility of lowering genetic purity from volunteer corn plants 

arising from a previous corn crop (Wych 1988). 

Conventional tillage and the removal of plant residue from soil are considered agriculture 

practices that accentuate loss of soil organic carbon (Lal and Bruce 1999). This loss has negative 

impacts on the atmosphere and increases soil erosion, among other effects. Because of numerous 

benefits to growers and the agricultural environment (Fawcett and Caruana 2001), it is not likely 

that DP-32138-1 will require a change from the increasingly prevalent practice of low-till 

production of corn. Under the No Action Alternative, the use of tillage methods in U.S. 

agricultural production of seed corn and commercial corn will remain unchanged. 

Under the No Action Alternative, corn production and pesticide use will remain as it is practiced 

today by the farming community. Growers make choices to use 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 system (Olson and Sander 1988; 

Giannessi 2005). Growers will ultimately base their choice of these inputs on individual wants 

and needs. As an example of the pesticides used during the production of field corn, the Pesticide 

Action Network has an online database, including a detailed description of all the pesticides used 

in corn agriculture in California (Kegley, Hill et al. 2010). It lists the top 50 pesticides (e.g., 

herbicides, insecticides, fungicides) used in California corn production. 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. 

Preferred Alternative: Crop Rotation, Tillage, Production, and Pesticide Use 

As stated above, the current economics of corn production are driving the change or perceived 

change in crop rotation practices (such as corn-to-corn cropping, Erickson and LowenbergDeBoer, 2005). A determination of nonregulated status of DP-32138-1 is unlikely to change the 

entire pricing scheme of corn commodities in the U.S. Prices will continue to be set by market 

demand, without regard to the number or type of corn varieties available on the market, nor to 

decreased costs of seed production. Based on information provided by the applicant, DP-32138-1 

lines containing transgenes are expected to reach an industry wide maximum of only 20,000 

acres in seed corn production, which is only 0.02% of the approximately 90 million acres 

planted to corn each year. DP-32138-1 is not likely to affect a farmer’s decision to either stop 

using a corn-to-corn rotation or other type of rotation, or to increase the overall use of corn-tocorn rotation or other type of rotation as a cropping strategy with the U.S. farming community. 
32

Adoption of DP-32138-1 will not change current production or cultivation practices. Crop 

rotation schemes that assure adequate isolation to maintain high genetic purity and tillage for 

seed corn production will remain the same. In those cases where seed producers employ 

conventional tillage for the inbred crops used in seed production, planting of DP-32138-1 will 

not change those practices, either. A determination of nonregulated status of DP-32138-1 will 

not change the loss of soil organic carbon due to tillage in seed corn production systems or in 

commercial production of corn in which DP-32138-1 was used in the production of hybrid seed. 

DP-32138-1 seed corn production uses the same agricultural inputs (e.g., pesticides, fertilizers) 

as seed corn currently grown. DP-32138-1 does not require different types of pesticides than are 

currently used in seed corn production. A determination of nonregulated status of DP-32138-1 

will not have any effect on the pesticides used in the production of seed corn or commercial 

corn production in the U.S., compared to the No Action Alternative. 

Cumulative Effects: Crop Rotation, Tillage, Production, and Pesticide Use 

A determination of nonregulated status of DP-32138-1 will not have any cumulative effect on 

the crop rotation, tillage and crop production practices or on the pesticides used in the production 

of seed corn or commercial corn production in the U.S., compared to the No Action Alternative. 

The limited number of seed corn production acres that may use DP-32138-1 lines containing 

transgenes is expected to have no cumulative effect on crop rotations, tillage and crop production 

practices, or pesticide use. The requirements for crop rotation, tillage and crop production 

practices, and pesticide use for the non transgenic hybrid progeny resulting from DP-32138-1 

seed production that will be used to plant conventional corn fields, will be exactly the same as 

those used for conventionally produced hybrids. 

Seed Production 

Seed corn production differs from commercial grain production because seed companies impose 

strict requirements to maintain seed identity and high levels of genetic purity of the final product. 

This purity is accomplished using contracts, tracking and traceability systems, quality assurance 

processes, record maintenance, auditing, proper labeling, appropriate sampling and testing and 

identity preservation systems (Sundstrom, Williams et al. 2002). An example of a successful 

identity preservation system are the Seed Certifications programs as used by the AOSCA which 

have maintained seed purity standards for national and international trade since the 1920s 

(Sundstrom, Williams et al. 2002). 

Seed increase for a new corn variety encompasses larger and larger acreage for each successive 

generation. The initial generation of the new inbred line consists of one or only a few plants. 

These plants will produce a few ears. The seeds from these few ears are used to plant a small 

plot, approximately 0.1 acres (3000-6000 sq. ft.). Early generation plants are self pollinated and 

pollen control is generally achieved by using bags over the tassels and ears. Using this system of 

pollen control allows many lines to be grown in a small area with an extremely low possibility of 

cross pollination with other lines grown in the immediate area. The 2-10 bushels of seed 

harvested are used to plant 2-20 acres for the next increase. Plants at this stage are also self 

pollinated to increase the seed; however, the area is likely too large for bagging as a means of 

pollen control. Pollen control is achieved by means of temporal or physical isolation from other 

lines. This increase produces 100 to 1000 bushels of inbred line seed. 
33

In the next stage, which produces single cross hybrid seed to be used for planting commercial 

corn grain fields, two different inbred lines (both are from the previous stage increase) are 

planted in the same field. One inbred line is considered the male line providing the pollen and 

the second line is the female line, from which the hybrid seed will be harvested. Procedures 

must be taken to prevent these plants of the female line from producing viable fertile pollen. 

Presently, detasseling or cytoplasmic male sterility systems are used to prevent self pollination 

of this stage female plants. 

The Pioneer Hi-Bred SPT process is designed to produce non-transgenic male-sterile female 

inbred parent plants for hybrid corn seed production without the need for tassel removal or 

bagging. As a process, SPT uses two types of inbred corn lines: 1) nontransgenic male-sterile 

inbred lines (referred to as ms45) that cannot produce pollen but can produce fertile egg cells, 

and 2) a transgenic male-fertile line containing a DP-32138-1 SPT maintainer cassette within the 

ms45 genetic background (referred to as DP-32138-1 corn) that permits pollen development in 

which half the pollen is non-transgenic and viable and the other half is transgenic but not viable. 

The maintainer can also produce fertile eggs which allows for production of new transgenic 

seeds of the maintainer line (see below). The DP-32138-1 SPT maintainer cassette contains 

three linked genes that are differentially expressed over time, including Ms45 (expressed in the 

anther), -amylase (expressed in the pollen grain), and dsRed (expressed in the kernel). 

The Pioneer Hi-Bred SPT process consists of three major steps (Figure 1): 1) DP-32128-1 seed 

increase, 2) non-transgenic ms45 male sterile corn increase, and 3) hybrid seed production using 

non-transgenic seed from use of the SPT process. The steps of this process are described in 

additional detail, below. 

Step 1: 32138 SPT Maintainer Seed Increase. The first major step of the Pioneer Hi-Bred SPT 

process propagates DP-32138-1 corn (see Step 1, Figure 1, and Figure 2). Propagation involves 

both the self-pollination of DP-32138-1 corn in the field and mechanical sorting to select for the 

desired seed. In contrast to a male sterile ms45 corn line, DP-32138-1 corn is able to produce 

pollen by means of the fertility trait MS45 which was engineered into the DP-32138 SPT 

maintainer cassette. Half of the pollen produced by DP-32138-1 corn contains the DP-32138-1 

SPT maintainer cassette and is not viable (pollen expresses a starch-consuming enzyme, ZMAA1); however, the remaining half of the pollen does not contain the DP-32138-1 SPT 

maintainer cassette and is fully viable. 

Both transgenic (where the DP-32138-1 SPT maintainer cassette is present) and non-transgenic 

(SPT absent) kernels are produced in 1:1 ratios, following the self-fertilization of DP-32138-1 

corn (Figure 2). Seed that is normal (yellow) in color is non-transgenic for SPT (does not 

contain the DP-32138-1 SPT insertion). Pinkish-red seed that fluoresces a bright red color 

under appropriate illumination is transgenic for SPT (contains the DP-32138-1 SPT insertion). 

In order to separate these two kernel types, mechanical color sorting is used to detect the the 

32138 SPT maintainer cassette (containing the dsRed fluorescent protein) (see Figure 3). The 

remaining kernels, non-transgenic due to the absence of the 32138 SPT maintainer cassette, are 

discarded after mechanical sorting. Pure seed of DP-32138-1 SPT maintainer is then available 

for the propagation of non-transgenic male-sterile female inbred parent seed (Figure 1, Step II). 

Yellow, non-transgenic seed collected from the first color sort will be discarded.
34

 Figure 1. Outline of the SPT Process for Producing Hybrid Seed.
35

 Source: (Pioneer 2009) 

Figure 2. Production of the 32138 SPT Maintainer Line (Figure 1, Step I). 

Step II: Male-Sterile Female Inbred Parent Seed Increase. The second major step of the Pioneer 

Hi-Bred SPT process produces male-sterile female inbred plants for use in hybrid seed 

production (Figure 1, Step II). This process involves the interplanting of both DP-32138-1 and 

ms45 corn (non-transgenic). Within this cross, DP-32138-1 represents the only pollen donor. 

Consequently, DP-32138-1 corn may cross with itself or with ms45 corn. Both transgenic 

(where the 32138 SPT maintainer cassette is present) and non-transgenic kernels (SPT cassette is 

absent) are produced following these crosses (Figure 4). Only the nontransgenic pollen is viable 

and can pollinate the male-sterile female inbred line. 

Similar to the previous step of DP-32138-1 propagation, mechanical color sorting is used to 

distinguish transgenic kernels from non-transgenic kernels; in contrast, however, two rounds of 

mechanical color sorting are used to select for non-transgenic kernels (absence of the dsRed 

fluorsence protein, and thus, absence of the 32138 SPT maintainer cassette) for use in hybrid 

seed production (see Sort B, Figure 3). Kernels expressing DsRed, and thus containing the 

32138 SPT maintainer cassette, are discarded after mechanical color sorting. 

Kernels produced from the second major component of the Pioneer Hi-Bred SPT process are 

non-transgenic. Consequently, any hybrid corn lines produced from these kernels are also nontransgenic. Additionally, propagation of both the DP-32138-1 (Stage I) and ms45 corn lines 

(Stage II) precedes commercial corn grain production by two generations. The final stage of of 

hybrid seed production is likely accomplished at a distant location relative to Stage I or II 

production, at seed production sites not directed by Pioneer (which handles the first stages of 

production). Consequently, because of the geographic separation of any seed that may contain 
36

Figure 3. Visualization of the Red Marker, DsRed2 Expressed by the SPT Cassette. 

Photograph A shows a corn ear with both the transgenic SPT cassette kernels/seeds (red coloring) 

and nontransgenic seeds (yellow coloring). Photograph B shows the SPT and the nontransgenic 

seed under standard illumination. Photograph C shows the SPT seed (+ DsRed2) and the nontransgenic seed (- DsRed2) under fluorescent illumination (Pioneer 2009). 

Figure 4. Production of the Non-Transgenic Female Sterile Inbred (Step II). 
37

Source: (Pioneer 2009) 

the 32138 SPT maintainer cassette, admixture by mechanical means of commercial corn grain 

with DP-32138-1 corn is unlikely. This unlikely potential for admixture with DP-32138-1 corn 

is further reduced by the relatively small cultivation acreage that will use the SPT technology; 

fields containing DP-32138-1 are not expected to exceed 20,000 acres or approximately 0.023 

percent of total U.S. corn grain producing acreage. 

Step III: Commercial Corn Hybrid Seed Production. Commercial corn hybrid seed production 

(Figure 1, Step III) using the male-sterile seed (nontransgenic) prepared using SPT technology 

will be completed as it is for conventional production methods. The purity of the male-sterile 

female inbred plants produced from the SPT process is insured in Step II because of the built-in 

biological feature in which transgenic pollen is non-viable and because the seed was passed 

twice through mechanical color sorters (refer to Pioneer 2009, Appendix 3 for details on the 

color sorter). Therefore, the hybrid seed harvested and sold to growers for commercial grain 

production is non-transgenic for SPT and the resulting hybrid plants are fully fertile. The hybrid 

seed grown for grain is non-transgenic for SPT and therefore, the grain harvested is also nontransgenic for SPT. 

The field sizes that will be used for any one corn variety at each step of increase can vary 

considerably depending on the present or expected market share of each variety, the level of 

testing to be conducted during the increase phase, and the expected yield of the inbred lines. In 

the case of corn, based on current production data, the amount of seed of all varieties combined 

must be sufficient to plant over 90 million acres each year (USDA-ERS 2010a). Since Pioneer, 

the applicant in this petition, has approximately a 30% market share and has approximately 250 

different corn hybrids available, this implies the number of corn varieties available industry-wide 

is about 800-1000 (Pioneer 2008; Pioneer 2010) with other estimates of over 4000 hybrids 

available in the U.S. in 2009 (Monsanto 2010). The development of new inbreds along with the 

Steps I and II seed increases are the stages when the transgenic plants of DP-32138-1 are 

expected to be in the field. The 250 Pioneer varieties multiplied by the 2-20 acre Step II increase 

per variety is the “up to 5000 acres” maximum acreage of DP-32138-1 to be used by Pioneer 

(Pioneer 2009). The industry-wide assumed total of 1000 to 4000 varieties multiplied by the 2 to 

20 acre Step II increase per variety equates to the “up to 20,000 acres” maximum acreage of 

DP-32138-1 to be utilized if adopted industry-wide (Pioneer 2009). In the Step III seed increase, 

DP-32138-1 confers its largest benefits through the planting of the non-transgenic, male sterile 

female inbred produced with DP-32138-1. Pioneer may avoid detasseling up to 300,000 acres, 

while other seed industry organizations may potentially have up to 1 million acres that would 

not require detasseling. 

No Action: Seed Production 

The availability of methods used to produce seed corn would be the same as currently used in 

seed corn production systems under the No Action Alternative. 

Preferred Alternative: Seed Production 

A determination of nonregulated status of DP-32138-1 corn under the Preferred Alternative 

would not change the use of presently available systems for seed corn production. DP-32138-1 

will be produced in a manner similar to other seed corn inbreds and resulting hybrids. As 

discussed above, these inbreds and resulting hybrids are typically produced under identity 
38

preservation systems that include contracts with growers, traceability, product tracking, and 

process verification since Pioneer and other seed corn companies take precautions to insure that 

inbred parent lines are not misappropriated by third parties. These procedures greatly minimize 

any chances of commingling of the DP-32138-1 seed with other seed and, ultimately, 

commercial grain. 

With the price premiums involved with production of any seed corn variety, including the DP32138-1 corn, there is no benefit for modifying any of the well known procedures to maintain 

high genetic purity. Using DP-32138-1 in the increase of corn varieties could reduce the yield 

losses associated with detasseling and the consequence would be fewer acres of increase needed 

per variety. Additionally, there could be a decrease in the number of people required for 

detasseling resulting in reduced expenses and fewer safety hazards during the seed corn 

increase. The assumed maximum use of 20,000 acres industry wide for DP-32138-1 is only 

about 0.02% of the 80-90 million acres of annual corn production. The agronomic practices 

used for these seed production acres would be almost identical to the agronomic practices and 

locations used under the No Action alternative, so no overall effects are anticipated. 

Discarded parent seed, whether it is outdated or discarded from the color sorter, and seed 

byproducts, such as husks and cobs, will be disposed by placing in landfills, composting, or 

incineration (Pioneer 2009). According to Pioneer policy, seed producers will not feed discard 

corn to animals (Public Comment on EA for DP-32138-1). 

Since the DP-32138-1 insertion has three separate genes, each of which is required for the 

production system to work correctly, APHIS considered the effects if one or two of these three 

genes were lost through mutation or recombination, which was addressed and discussed in 

detail in the petition (Pioneer 2009). DP-32138-1 will maintain the propagation of the male 

sterile female inbred as well as eliminate detasseling. All of the plants in Steps I, II, and III are 

inspected for off-type characteristics and any off-types will be rogued out. Since Step I and II 

fields are very small, these fields can be expected to be inspected more heavily than the larger 

Step III fields. In conventional seed corn production, fields under Steps I, II, and III of seed 

production are similarly inspected for plants with off-type characteristics, so the inspection 

process is not an additional step required for DP-32138-1 corn. There is the possibility that the 

mutation or recombination could take place at a very low frequency during Step II allowing a 

very low frequency of female inbred plants that would also have male fertility in Step III. This 

frequency would be expected to be much lower than the incomplete detasseling that happens 

during conventional seed production. None of these plants would produce seeds with the 

DsRed2 color marker protein, the only non-native corn protein in DP-32138-1 corn. Please refer 

to the petition for the complete analysis (Pioneer 2009). 

There is always the remote possibility for misdirection of DP-32138-1 in the handling, planting, 

harvesting, transportation or processing stream. Because DP-32138-1 has successfully completed 

the new protein consultation process for the DsRed2 color marker protein with FDA (Appendix 

A), there are no human or animal health concerns if DP-32138-1 enters the food or feed 

supply (see section on Public Health below for more discussion). 

Cumulative Effects: Seed Production 

Because the acreage, agronomic practices, and locations for seed production using DP-32138-

1 are expected to be the same or similar to the No Action alternative, no cumulative effects 

have been identified for this issue. 
39

Organic Farming 

Certified organic corn acreage is a small percentage of overall corn production. The most 

recently available data show 143,000 acres of organic corn production in 2007. This is 0.17% of 

the total 86.2 million acres of corn planted in 2007 (USDA-ERS 2008). In 2005, 131,000 acres 

of organic corn were planted resulting in a 9% increase in organic corn acreage over the 2 year 

period from 2005 to 2007 (USDA-ERS 2010a). GE corn has been in production since the mid1990’s, and in 2009 accounted for 85% of the 86.7 million acres of corn planted (USDA-NASS 

2009a). GE corn production and organic corn production in the U.S. are both increasing. Based 

upon trend data, it is anticipated that both production practices will likely continue to increase 

with or without a determination of nonregulated status of DP-32138-1. APHIS also recognizes 

that producers of non-GE corn, particularly producers who sell their products to markets 

sensitive to genetically engineered traits (e.g. organic or some export markets) can be reasonably 

assumed to be using practices on their farm to protect their crop from unwanted substances and 

maintain their price premium. For example, the NOP has recognized the practicality of 

protecting organically-produced crops, and the investment farmers put into their production 

practices, by requiring that organic production plans include methods to protect organicallyproduced crops. “Organic crops must be protected from contamination by prohibited substances 

used on adjoining lands (for example, drifting pesticides, fertilizer-laden runoff water, and pollen 

drift from genetically engineered...)” (NCAT 2003). 

Typically, there is more than one method for farms under organic practices 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, as well as formal 

communications between neighboring farms (NCAT 2003). The organic plan used as the basis 

for organic certification should include a description of practices used to prevent or reduce the 

likelihood of unwanted substances, like GE pollen or seed, at each step in the farming 

operation, such as planting, harvesting, storing and transporting the crop (Riddle 2004; Krueger 

2007; Kuepper, Born et al. 2007). Organic plans should also include mechanisms to monitor the 

risk of GE pollen or seed co-mingling with the organic crop (Kuepper, Born et al. 2007). 

Farmers using organic methods are requested to let neighboring farmers know that they are 

using organic production practices and request that the neighbors also help the organic farmer 

reduce contamination events (NCAT 2003; Krueger 2007). Thus, commonly used production 

practices for corn, and the practical methods typically used by corn farmers using organic 

methods currently provide many measures that greatly reduce the likelihood of accidental gene 

flow between DP-32138-1 and non-GE corn fields. These practices protect organic crops and 

thus maximize profits and price premiums accorded to corn under organic production. APHIS 

will assume that farmers are already using, or have the ability to use, these common practices as 

APHIS’ baseline for the analyses of the following alternatives below. Recommended organic 

production practices for field corn are also readily available (Kuepper 2002). Without any 

requirements in place for GE corn varieties previously deregulated pursuant to Part 340 and the 

Plant Protection Act, the production of corn using organic methods continues to increase. 

In agricultural systems, growers may choose to grow GE or non-GE corn, and obtain price 

premiums for growing varieties of corn for particular markets (e.g., using organic methods for 

corn production or producing a specialty corn variety for particular processing needs). For 

example, in 2007, conventional corn averaged $4.19/bushel (USDA-NASS 2010b), whereas 

organic corn averaged $7.08/bushel (USDA-NASS 2010c). USDA asserts that agricultural 
40

practices that use conventional means, organic production systems, or genetically engineered 

varieties can all provide benefits to the environment, consumers, and farm income. 

No Action: Organic Farming 

Current availability of seed for conventional (both GE and non-GE) corn varieties, and those corn 

varieties that are developed for organic production, are expected to remain the same under the No 

Action Alternative. Commercial production of conventional and organic corn will not change 

and will remain the same under the No Action Alternative. Planting and production of GE corn 

varieties and organic corn have both increased due to market demands over the last ten years, 

and these markets are likely to continue to increase under the No Action Alternative (USDANASS 2010a; USDA-NASS 2010c). 

Preferred Alternative: Organic Farming 

It is not likely that organic farmers who choose not to plant transgenic varieties or sell transgenic 

grain will be impacted from the use by the developer of DP-32138-1 corn or by other developers 

licensed to use the corn. Commonly used production practices for corn, and the practical 

methods typically used by corn farmers using organic methods to protect their crop under 

organic production (NCAT 2003) provide many measures that greatly reduce the likelihood of 

accidental gene flow between DP-32138-1 and non-GE corn fields. Pollen from DP-32138-1 

corn containing SPT transgenes is not functional and as a result will not fertilize corn plants. 

Therefore, DP-32138-1 corn is not likely to affect neighboring farms. Similar to the No Action 

Alternative, the use of GE corn varieties and the use of organic corn production systems are 

likely to continue a trend toward increasing production under the Preferred Alternative. 

According to the petition, no transgenes will be present in the seed for planting the Step III 

increase acres (Pioneer 2009). Likewise, after the seed harvest of Step III, the seed for planting 

Step IV will also contain no transgenes in either commercial corn grain fields or in the harvest 

from the grain fields (Pioneer 2009). 

A determination of nonregulated status of DP-32138-1 will not impact the availability of seed 

corn for organic production systems. In accordance with NOP production standards (7 CFR 

205.204a) “the producer must use organically grown seed, annual seedlings, and planting stock: 

except, that (1) Nonorganically produced, untreated seeds and planting stock may be used to 

produce an organic crop when an equivalent organically produced variety is not commercially 

available.” Organic seed corn is commercially available and therefore in accordance with NOP 

organic seed corn must be used in certified organic corn production systems. The use of DP32138-1 will have no impact on a grower’s ability to obtain seed corn for organic production 

systems. The Organic Trade Association provides available resources to locate suppliers that sell 

organic seeds including corn (OTA 2010). 

Cumulative Effects: Organic Farming 

Under the No Action Alternative and under the Preferred Alternative, a determination of 

nonregulated status of DP-32138-1 will not change the market demands for GE corn or corn 

produced using organic methods. A determination of nonregulated status of DP-32138-1 will 

not add another GE corn variety to the conventional corn market, since the SPT genes are 

confined to the seed production process, and are not found in the commodity corn. The SPT 

technology will not change the amount of GE corn available for production, because it will only 
41

replace detasseling operations. Additionally, based upon recent trend information, the market 

changes of conventionally farmed corn varieties are not related to the ability of organic 

production systems to increase their market share. Between 2002 and 2008, acreage of 

conventionally farmed corn varieties increased by 12% (USDA-ERS 2010d) while the acreage 

associated with the organic production of corn rose 50% during this same time period (USDAERS 2008). 

Specialty Corn Systems 

Specialty corn, such as waxy corn, white corn, blue corn, and organic corn, comprises 8% of the 

U.S. market (USGC 2006). With 85% of conventional corn being GE varieties in 2009, a 

market exists for non-GE corn with low or no level of GE corn. The size of this non-GE corn 

market, generally for Japan and Europe, was 300,000 to 550,000 acres in 2005 with a flat 

projected growth (USGC 2006). These specialty corn products intensively use systems to 

maintain the purity of the corn product, based on the demands of the end-user (e.g., food 

processing plants). 

No Action: Specialty Corn Systems 

The availability of methods used to separate specialty corn products from corn used as grain 

would remain the same. 

Preferred Alternative: Specialty Corn Systems 

A determination of nonregulated status of DP-32138-1 under the Preferred Alternative would 

not change the availability of using contracts, tracking and traceability systems, quality 

assurance processes, closed-loop systems, and identity preservation systems to maintain 

product purity for specialty corn production. Impacts would be similar to the No Action 

Alternative. 

Cumulative Effects: Specialty Corn Systems 

The availability of methods used to separate specialty corn products from corn used as grain would 

be the same as currently used in corn production systems, and no changes are foreseeable. No 

cumulative effects have been identified for this issue. 

Physical Environment 

Water Resources 

Since inbreds are much less vigorous than hybrids, irrigation can be preferred in the seed 

production of inbreds to help assure desired seed yields (Wych 1988), especially in those areas 

subject to frequent droughts. 

No Action: Water Use 

Under the No Action Alternative, DP-32138-1 interactions with water would be limited to the 

areas that were approved for regulated releases by APHIS. Irrigation practices associated with 

conventional seed corn production would not be affected. Under the No Action Alternative, 

there is no change in the conventional seed production procedures of irrigating corn inbred lines 

in drought prone areas and no change in irrigation practices of commercial corn production. 
42

Preferred Alternative: Water Use 

Impacts would be similar to the No Action Alternative. DP-32138-1 does not change cultivation 

practices for seed production of corn inbreds. A determination of nonregulated status of DP32138-1 will not change the use of irrigation practices in seed corn production or commercial 

corn production. The very small number of acres involved is an additional reason that the use of 

DP-32138-1 in seed corn production is expected to have no effect on water use. Since hybrid corn 

will not contain the DP-32138-1 transgenes or non-native corn proteins at the commercial stage 

of planting and harvesting, the consequences of the Preferred Action Alternative on commercial 

corn production are the same as the No Action Alternative.

Cumulative Effect: Water Use 

No cumulative effects have been identified for a determination of nonregulated status of DP32138-1 corn. A determination of nonregulated status of DP-32138-1 will not change the 

current irrigation practices used in seed corn production or commercial corn production. 

Soil 

Certain agronomic practices such as cultivation cause disturbance and exposure of the top 

surface layer of soils and allow some soils to be prone to degradation. Two environmental 

impacts of soil degradation are the decline in water quality and the possible contribution of 

additional CO2 towards climate change (Lal and Bruce 1999). One production step for corn 

seed that may have detrimental effects on soil are detasseling operations. Detasseling must take 

place, rain or shine, when the tassels start to appear on the plant. If the soil is wet, using heavy 

implements, such as the detasseler carriers and the mechanical detasselers, produce large ruts in 

the soil. These ruts result in damage to the corn roots and negatively impact soil structure which in 

turn change water movement and nutrient uptake by plants (Daum 1996; Kok, Taylor et al. 1996; 

Gelderman 2009; Tilghman 2009; Roegge 2010). 

Detasseling operations resulting in soil compaction could also potentially affect subsurface 

soil and constituent organisms. The soil environment in and around corn fields is complex, 

and rich in microorganisms and arthropods. The corn root system modifies soil through its 

close association with several microbial groups such as bacteria, fungi, protozoa, and mites 

(Bais, Weir et al. 2006). Bacteria typically represent the most abundant microbes in the soil 

followed by fungi. These microbial groups play an important and particular role in the ecology of 

the soil, including nutrimental cycling and the availability of nutrients for plant growth (Hoeft, 

Nafziger et al. 2000; OECD 2003) 

No Action: Soil 

DP-32138-1 interactions with the soil would be limited to the areas that are approved by APHIS 

for regulated releases. Cultivation practices associated with conventional seed corn production 

would not be affected. The soil environment would be modified by corn roots and crop soils 

would still be affected by agronomic practices associated with conventional seed corn 

cultivation, including the negative impacts associated with detasseling when soils are wet. 

Cultivation practices associated with commercial production of corn would not be affected. 

Preferred Alternative: Soil 
43

In the event of a determination of nonregulated status of DP-32138-1 under the Preferred 

Alternative, soil interactions with DP-32138-1 would occur at a larger scale than under the 

regulated releases. DP-32138-1 seed corn production could have three possible effects on soils 

as compared to conventional seed corn production: no effects from detasseling, possible presence 

of additional ZM-AA1 alpha-amylase protein, and possible presence of DsRed2 color marker 

protein. 

Cultivation practices associated with DP-32138-1 seed corn production would be the same as 

conventional seed corn production during seedbed preparation, planting and early plant 

development. The soil environment would be modified by corn roots and crop soils would still 

be affected by agronomic practices associated with conventional seed corn cultivation. However, 

for DP-32138-1 seed corn production, detasseling would no longer be required and the negative 

consequences of detasseling would be avoided, such as compaction and large ruts in the soil. 

Generally these seed corn production fields, including DP-32138-1 seed corn fields, are in 

rotation with other crops. These rotations with other non-corn crops generally result in averaging 

out any positive or negative impacts that may have resulted from the seed corn production. These 

positive or negative effects cannot be quantified because the DP-32138-1 seed corn fields are a 

very small proportion of commercial corn production. In comparison to commercial corn grain 

production in which no detasseling takes place, DP-32138-1 seed corn would be no different. 

DP-32138-1 expresses small amounts of ZM-AA1 alpha-amylase protein during plant 

development and only at low levels in the seed at physiological maturity (Pioneer 2009). In both 

conventional and DP-32138-1 seed corn production, the rows of male plants are generally 

destroyed to aid in increasing seed yield of the female rows by decreasing plant competition and 

to decrease the chances of commingling of male and female seeds at harvest (Pioneer 2009). In 

DP-32138-1 corn, the plants that contain the transgenes (male fertile) would be destroyed 

following pollination, generally by chopping up the plant. These immature plants contain low 

levels of ZM-AA1 alpha-amylase protein throughout plant tissues. Consequently, there is a 

potential for ZM-AA1 alpha-amylase protein to be incorporated into agricultural soils. However, 

alpha-amylases are ubiquitous enzymes found in microorganisms, plants, and animals (Janeček, 

Lévêque et al. 1999). 

If the DP-32138-1 plants are allowed to reach physiological maturity, these plants are generally 

harvested with most, if not all, of the seed removed from the field. For seed that may remain in 

the field after harvest, physiologically mature seed of DP-32138-1 will contain low levels of ZMAA1 alpha-amylase protein. However, if soil moisture and temperatures are adequate to 

stimulate germination, seeds of both conventional and DP-32138-1 would produce similar 

amounts of ZM-AA1 alpha-amylase protein. Since the levels of ZM-AA1 alpha-amylase protein 

are essentially the same in conventional corn and DP-32138-1 corn, impacts of DP-32138-1 seed 

corn production on the soil would be similar to those in conventional corn seed production. 

DP-32138-1 expresses small amounts of the DsRed2 color marker protein during plant 

development with the highest levels in the seed detected at physiological maturity (Pioneer 

2009). During the production of non transgenic male sterile inbred for seed increase, plants that 

contain the transgenes may be chopped and left on the soil surface (Pioneer 2009). These 

immature plants express low levels of DsRed2 color marker protein throughout the plant. The

DsRed2 color marker protein will be susceptible to degradation and adsorption to humus or 

minerals as are other proteins in agricultural soils (Bastida, Moreno et al. 2009). Soils contain 

numerous organisms and enzymatic activity from decomposed organisms that degrade a wide 
44

array of molecules including proteins (Bastida, Moreno et al. 2009). These processes would 

metabolize or sequester the DsRed2 color marker protein with no likely effect on the soil. 

If the DP-32138-1 plants are allowed to reach physiological maturity, these plants are generally 

harvested with most, if not all, of the seed removed from the field. In the few seeds that may 

remain in the field after harvest, physiologically mature seed of DP-32138-1 will contain 

DsRed2 color marker protein. Similar to DsRed2 that originated in whole plants, normal soil 

degradation and adsorption would be expected to remove this protein. 

 For the preferred alternative of deregulating DP-32138-1 corn, the three possible effects of no 

detasseling, possible presence of additional ZM-AA1 alpha-amylase protein and possible 

presence of DsRed2 color marker protein combined with the very low presence in the 

environment (a maximum 20,000 acres), impacts on soil are expected to be similar to those from 

conventional corn seed production. Since hybrid corn will not contain the DP-32138-1 

transgenes or non-native corn proteins at the commercial stage of planting and harvesting, the 

consequences of the Preferred Action Alternative on commercial corn production are the same as 

the No Action Alternative.

Cumulative Effects: Soil 

APHIS has not identified any cumulative effects for this issue. The fields devoted to seed corn 

production, conventional as well as DP-32138-1 seed corn, are normally rotated with other crops 

with the maximum potential for 20,000 acres expected to be devoted to DP-32138-1 seed corn. 

DP-32138-1 seed corn acres would be only 0.02% of all corn production acres. APHIS 

concludes that adverse effects of the ZM-AA1 alpha-amylase protein or of the DsRed2 color 

marker protein are not likely, effects of avoiding detasseling are slightly positive, if any, and 

exposure of 0.02% of all annual corn production acres is small, and therefore with adverse 

impacts on soil unlikely, no cumulative impacts are likely. Since hybrid corn will not contain the 

DP-32138-1 transgenes or non-native corn proteins at the commercial stage of planting and 

harvesting, the effects of the the Preferred Action Alternative on commercial corn production are 

not significant and are therefore no cumulative effects are expected.

Air Quality 

Tillage, traffic and harvest emissions, pesticide drift from spraying, and nitrous oxide emissions 

from the use of nitrogen fertilizer may affect air quality (Aneja, Schlesinger et al. 2009). Tillage 

contributes to the release of GHGs because of the loss of CO2 to the atmosphere, and the 

exposure and oxidation of soil organic matter (Baker, Southard et al. 2005). Emissions released 

from agricultural equipment (e.g., irrigation pumps and tractors) include carbon monoxide, 

nitrogen oxides, reactive organic gases, particulate matter, and sulfur oxides (US-EPA 2010). 

Nitrous oxide may also be released following the use of nitrogen fertilizer (US-EPA 2010). 

Aerial application of pesticides may cause impacts from drift and diffusion. Pesticides may 

volatilize after application to soil or plant surfaces and move following wind erosion (Vogel, 

Majewski et al. 2008). Agriculture, including land-use changes for farming, is responsible for an 

estimated 6% of all human-induced GHG emissions in the U.S., and N2O emissions from 

agricultural soil management are a large part of this, 68 % of all U.S. N20 emissions (US-EPA 

2010). 

No Action: Air Quality 
45

Under the No Action Alternative, DP-32138-1 interactions with the air would be limited to the 

areas that were approved for regulated releases by APHIS. Cultivation practices associated 

with conventional seed corn production or commercial corn production would not be affected. 

Air quality would still be affected by agronomic practices associated with conventional seed corn 

cultivation and commercial corn production such as tillage, pesticide application, and use of 

agricultural equipment. 

Preferred Alternative: Air Quality 

DP-32138-1 seed corn production does not change cultivation practices for seed production of 

corn inbreds. A determination of nonregulated status of DP-32138-1 will not change the use of 

tillage, use of agriculture equipment, irrigation, pesticide applications and fertilizer applications 

in seed production or commercial corn production. With DP-32138-1, no detasseling would be 

required, subsequently reducing the combustion gas emissions from detasseler carriers, 

mechanical detasselers and movement of detasselers between homes and seed fields resulting in 

a beneficial effect on air quality. Considering the very small number of acres involved, the use 

of DP-32138-1 in seed corn production is expected to have minimal effects on air quality. 

Since hybrid corn will not contain the DP-32138-1 transgenes or non-native corn proteins at the 

commercial stage of planting and harvesting, the consequences of the Preferred Action 

Alternative on commercial corn production are the same as the No Action Alternative.

Cumulative Effects: Air Quality 

APHIS has not identified any cumulative effects for this issue. The use of DP-32138-1 in seed 

corn production is expected to have no cumulative effect on air quality because of the very small 

number of acres that would be involved in DP-32138-1 seed corn production and there are no 

changes in cultivation practices. Since hybrid corn will not contain the DP-32138-1 transgenes or 

non-native corn proteins at the commercial stage of planting and harvesting, the effects of the 

Preferred Action Alternative on commercial corn production were not significant, and 

consequently there are unlikely to be any cumulative effects. 

Climate Change 

Production of agricultural commodities is one of the many human activities that could possibly 

GHGs that affect climate (see discussion in Affected Area, Physical Environment). CO2, 

nitrogen dioxide (NO2), and methane (CH4) may be produced through the combustion of fossil 

fuels to run farm equipment, the use of fertilizers, or the decomposition of agricultural waste 

products including crop residues and animal wastes. Classes of crops planted are relevant to 

climate change, as are the locations and the soil types in which they are planted. Climate change 

itself may force changes to agricultural practices by extending the ranges of weeds and pests of 

agriculture (IPCC 2007). Indirect effects of new crops will be determined by the traits 

engineered into organisms and the management strategies used in the production of these 

organisms. 

No Action: Climate Change 

Under the No Action Alternative, environmental releases of DP-32138-1 would be under APHIS 

regulation. There would be no measurable effect from these confined environmental 

releases. Cultivation practices associated with conventional seed corn production or 
46

commercial corn production would not be affected. Agronomic practices associated with 

conventional seed corn cultivation or commercial corn production such as tillage, pesticide 

application, and use of agriculture equipment would remain the same. 

Preferred Alternative: Climate Change 

DP-32138-1 seed corn production does not change cultivation practices for seed production of 

corn inbreds. A determination of nonregulated status of DP-32138-1 will not change the use of 

tillage, use of agriculture equipment, irrigation, pesticide applications and fertilizer applications 

in seed production on commercial corn production. With DP-32138-1, no detasseling would be 

required, consequently reducing the energy requirements for detasseler carriers, mechanical 

detasselers and for movement of detasselers between homes and seed fields resulting in a 

reduced level of greenhouse gases. However, with the relatively small number of acres that 

would be involved with seed corn production using DP-32138-1 a slight decrease of GHG 

production is likely too small to calculate any meaningful impact for climate change. Since 

hybrid corn will not contain the DP-32138-1 transgenes or non-native corn proteins at the 

commercial stage of planting and harvesting, the consequences of the Preferred Action 

Alternative on commercial corn production are the same as the No Action Alternative.

Cumulative Effects: Climate Change 

APHIS has not identified any cumulative effects for this issue. The use of DP-32138-1 in seed 

corn production is expected to have no cumulative effect on climate change because of the very 

small number of acres that would be involved in DP-32138-1 seed corn production and there are 

no changes in cultivation practices. Since hybrid corn will not contain the DP-32138-1 transgenes 

or non-native corn proteins at the commercial stage of planting and harvesting, the effects of the 

Preferred Action Alternative on commercial corn production were not significant, and 

consequently there are no cumulative effects expected.

Animal and Plant Communities 

Animals 

Corn production systems in agriculture are host to many animal species. Mammals and birds may 

seasonally use grain, and invertebrates can feed on the plant during the entire growing season. 

The cumulative effects analysis for this issue is found below at “Cumulative Effects: Plants, 

Animals, Biodiversity.” 

No Action: Animals 

Under the No Action Alternative, environmental releases of DP-32138-1 would be under APHIS 

regulation. Animal incursions would be limited to regulated field trials. The new protein 

consultation with FDA was successfully completed for DsRed2 color marker protein, the only 

non native corn protein in DP-32138-1 (Appendix A), which addressed any concerns of 

composition. The consultation demonstrated a lack of toxicity and allergenicity of DP-32138-1 

for human and animal consumption. Based upon the FDA’s new protein consultation, APHIS 

supports Pioneer’s conclusions that corn produced using Pioneer’s SPT technology is considered 

safe for animal consumption. 

Preferred Alternative: Animals 
47

APHIS has reviewed and accepts the data submitted by the applicant, which are similar to the 

data submitted during the FDA new protein consultation process for DsRed2 color marker 

protein, the only non native corn protein in DP-32138-1 (Appendix A). Impacts would be 

similar to the No Action Alternative. The agronomic practices used to produce DP-32138-1 

will be the same as those used to produce conventionally grown seed corn. Therefore, the 

discussion of effects on animals of DP-32138-1 will focus solely on the introduced proteins in 

DP-32138-1 corn, the ZM-AA1 alpha-amylase protein and the DsRed2 color marker protein. 

Pioneer DP-32138-1 has not been genetically engineered to produce any pesticides. DP-32138-

1 contains the ZM-AA1 protein in the developing pollen and in other parts of the plant at low 

levels except at physiological maturity when it has declined below the limits of quantitation 

(Pioneer 2009). The ZM-AA1 alpha-amylase protein is normally found predominantly in 

germinating kernels (sprouts) of conventional corn. Amylases may also be found in germinating 

pollen (Bhadula and Sawhney 1989; Castro and Clement 2007), including corn (Brewbaker 

1971; Agarwala, Sharma et al. 1981; Wakhle, Phadke et al. 1983). In DP-32138-1, ZM-AA1 

concentration is 400 times greater in pollen than in seed and 64 times greater than in R4 stage 

leaves. The alpha-amylases are ubiquitous enzymes present in many organisms including plants 

and insects (Campos, Xavier-Filho et al. 1989; Raimbaud, Buleon et al. 1989; Silva, Terra et al. 

1999; Cristofoletti, Ribeiro et al. 2001). The alpha-amylases from multiple sources including 

plants, fungi and bacteria have a long history of safe consumption in foods (Pariza and Johnson 

2001). Animals that feed primarily on corn kernels are seed-feeding insects and rodents found in 

agricultural fields. During field trials, the applicant found no differences in insect feeding 

damage (Pioneer 2009), indicating similar insect susceptibility of DP-32138-1 tissues and 

conventional corn.

DP-32138-1 contains the DsRed2 color marker protein in the seed (410 ng/mg tissue dry weight) 

but not in leaves or pollen of physiologically mature plants, and at lower levels in leaves (87 

ng/mg during the vegetative growth stage and 160-210 ng/mg during the early reproductive 

stages of growth) of the growing plant (Pioneer 2009). Rodents, such as mice or squirrels, in some 

seasons may feed exclusively on corn kernels. Thus, these animals are most likely to have a diet 

containing large amounts of corn kernels. DsRed2 showed no signs of toxicity when used as a 

vital marker in mice (Figueiredo, Fernandes et al. 2008). In a feeding study of mice to determine 

acute toxicity level of the DsRed2 protein, a wide margin of safety was observed (Pioneer 2009). 

Other mammals, such as deer, would have even lower exposure to DsRed2 color marker protein 

and ZM-AA1 alpha-amylase protein because of feeding habits; for example, deer nibble on tips 

of corn ears as opposed to kernels (Steffey, Rice et al. 1999). Finally, transgenic plants stably 

expressing DsRed variants did not show any abnormalities in growth habits, development, 

fertility, germination or morphogenesis (Jach, Binot et al. 2001; Dietrich and Maiss 2002; Stuitje, 

Verbree et al. 2003; Wenck, Pugieux et al. 2003; Mirabella, Franken et al. 2004; Pioneer 2009). 

APHIS has reviewed this information and has determined that there would be no negative 

effects to animals that forage on DP-32138-1 corn (USDA-APHIS 2010). 

Plants 

Corn production acreage is host to many plant species as well. The landscape surrounding a 

corn field varies depending on the region. In certain areas, corn fields may be bordered by other 

corn (or any other crop); fields may also be surrounded by wooded or pasture/grassland areas. 

Therefore, the types of vegetation, including weeds, around a corn field depend on the area 

where the corn is planted. A variety of weeds dwell in and around corn fields; those species will 
48

also vary depending on the geographic region where the corn is planted. Corn itself is not 

sexually compatible with any other plant species found in the U.S. (USDA-APHIS 2010). The 

cumulative effects analysis for this issue is found below at “Cumulative Effects: Plants, Animals, 

Biodiversity.” 

No Action: Plants 

Under the No Action Alternative, environmental releases of DP-32138-1 would be under APHIS 

regulation. Plant species that typically inhabit corn production systems will be managed as in 

conventional corn production, including the use of mechanical, cultural, and chemical control 

methods. 

Preferred Alternative: Plants 

In the event of a determination of nonregulated status of DP-32138-1, agricultural practices used 

for conventional corn would be used for plant management during the cultivation of DP-32138-1 

corn. Impacts would be similar to the No Action Alternative. DP-32138-1 does not exhibit 

characteristics associated with weedy growth and will not compete with plants found outside of 

agricultural production (USDA-APHIS 2010). Weeds within fields of DP-32138-1 will be 

managed using mechanical, cultural, and chemical control, as weeds are now managed in 

conventional corn systems. As there are no toxic effects on animals (see Animals discussion 

above), there are no toxic effects on animals that could be pollinators of other plants in or around 

fields cultivated with DP-32138-1 corn. DP-32138-1 has not been genetically engineered to be 

tolerant to any herbicides. 

Biological Diversity 

Biological diversity, or the variation in species or life forms in an area, is highly managed in 

agricultural systems. Farmers typically plant crops that are genetically adapted to grow well in a 

specific area of cultivation and have been bred for a specific market. In the case of corn 

agriculture, varieties have been developed for food processing needs (e.g., waxy corn), consumer 

qualities (e.g., blue corn or white corn), or for use as a vegetable (e.g. sweet corn). In 

conventional agriculture, farmers want to encourage high yields from their corn crop, and will 

intensively manage the ‘plant communities,’ or weeds, found in corn crops through chemical, 

cultural or mechanical means. Animals, particularly insect and other pest species will also be 

managed through chemical and cultural controls to protect the crop from damage by certain 

animal pests. Therefore, the biological diversity in agricultural systems (the agro-ecosystem) is 

highly managed and may be lower than in the surrounding habitats. The cumulative effects 

analysis for this issue is found below at “Cumulative Effects: Plants, Animals, Biodiversity.” 

No Action: Biological Diversity 

Under the No Action Alternative, environmental releases of DP-32138-1 would be under 

APHIS regulation. Animal and plant species that typically inhabit seed corn and commercial 

production systems will be continue to be affected by the management plan of typical 

conventional corn production, which includes the use of mechanical, cultural, and chemical control 

methods. 

Preferred Alternative: Biological Diversity 
49

The importance of corn as a food crop, and its dependence on human management, has 

produced a long history of effort to protect the integrity of the germplasm lines of corn. 

Decades prior to the introduction of transgenic corn products, the corn industry developed 

effective methods and means to maintain product segmentation and standards of genetic purity. 

Specialty corn crops, for example, were successfully isolated over long term cultivation and 

continue to be grown today, even with transgenic commodity corn widely adopted in the U.S. 

Moreover, with respect to both conventional and transgenic corn, the ability to protect and 

maintain the genetic purity of breeding lines is critical to seed companies and developers of 

new technologies such as DP-32138-1. Consequently, seed companies routinely apply standard 

breeding techniques, including physical and temporal isolation, which have proven effective at 

maintaining the genetic purity of breeding lines (Wych 1988). 

Genetically engineered corn lines have been available on the market since 1994 and the 

preponderance of evidence in peer-reviewed literature does not establish any consistent adverse 

effect of its production on biodiversity (Bitzer, Rice et al. 2005; Torres and Ruberson 2005; 

Romeis, Meissle et al. 2006; Marvier, McCreedy et al. 2007; Chen, Zhao et al. 2008; 

Wolfenbarger, Naranjo et al. 2008). APHIS’ review and analysis of Pioneer’s data (USDAAPHIS 2010) indicate that the line DP-32138-1 exhibits no traits that would cause increased 

weediness, that its unconfined cultivation should not lead to increased weediness of other 

cultivated corn or other sexually compatible relatives, and that it is unlikely to harm non-target 

organisms common to the agricultural ecosystem or threatened or endangered species recognized 

by the U.S. Fish and Wildlife Service. 

Cultivation of DP-32138-1 seed corn requires the same agronomic practices as conventional 

seed corn production. Animal and plant species that typically inhabit seed corn production systems 

will be managed as in conventional corn production, likely with the use of mechanical, cultural, 

and chemical control methods. Overall impacts would be similar to the No Action Alternative. 

Since hybrid corn will not contain the DP-32138-1 transgenes or non-native corn proteins at the 

commercial stage of planting and harvesting, the consequences of the Preferred Action 

Alternative on commercial corn production are the same as the No Action Alternative. 

Cumulative Effects: Animals, Plants, Biodiversity 

APHIS has determined that there are no impacts from past, present, or reasonably foreseeable 

actions that would aggregate with effects of the proposed action to create cumulative impacts or 

reduce the long-term productivity or sustainability of any of the resources associated with the 

ecosystem in which the DP-32138-1 is planted. DP-32138-1 has not been genetically engineered 

to produce a toxin or pesticide, and has not been genetically engineered to be tolerant to an 

herbicide. Although some studies have found both increases and decreases in animal and plant 

diversity and abundance in the agro-ecosystem due to the use of GE crops (Hansen Jesse and 

Obrycki 2000; Ponsard, Gutierrez et al. 2002; Brooks, Bohan et al. 2003; Haughton, Champion 

et al. 2003; Hawes, Haughton et al. 2003; Marshall, Brown et al. 2003; Roy, Bohan et al. 2003; 

Romeis, Dutton et al. 2004; Sisterson, Biggs et al. 2004; Bitzer, Rice et al. 2005; Pilcher, Rice et 

al. 2005; Torres and Ruberson 2005; Romeis, Meissle et al. 2006; Marvier, McCreedy et al. 

2007; Chen, Zhao et al. 2008; Wolfenbarger, Naranjo et al. 2008), DP-32138-1 is unlikely to 

affect the animal or plant communities found in conventional corn production systems because 

of the lack of toxicity and allergenicity, and because there will be no change to agronomic 

practices caused by the cultivation of DP-32138-1corn. 
50

Gene Movement 

An environmental impact to consider as a result of planting this corn variety is the potential for 

gene flow (the transfer of genetic information between different individuals or populations). Pollen 

flow, or the movement of genes from one plant to another, occurs between plants that are 

sexually-compatible, or able to receive pollen at the appropriate time during the appropriate plant 

stage. Corn does not have sexually-compatible relatives found in ‘natural’ areas; in the U.S., 

corn is only able to reproduce with other cultivated corn plants (USDA-APHIS 2010). 

Corn pollen moves by the wind (OECD 2003). Successful gene movement from one plant to 

another requires many different biological and physical factors, such as synchrony of 

flowering between corn fields, viability of pollen, and presence of physical barriers 

(OECD 2003); thus pollen movement is not equivalent to gene movement. A recent paper 

(Sanvido, Widmer et al. 2008) reviewed studies investigating gene flow and gene movement 

studies in corn grain production fields, and using the data found that the gene movement 

from GE corn to non-GE corn typically remained below 0.5% at 50m (approx. 164ft). In large 

scale studies, this same frequency of cross-fertilization events was similarly validated (Henry, 

Morgan et al. 2003; Weber, Bringezu et al. 2007). 

One study found cross-fertilization rates higher at comparable distances than other studies 

(Jones and Brooks 1950). Jones and Brooks (1950) found successful gene movement to be as 

high as 2.5 % at 660ft. One potential reason for the discrepancy between this study and most 

other gene flow studies in corn may be a result of the type of corn used in this study. Jones 

and Brooks (1950) investigated the appropriate isolation distance for seed production in 

open-pollinated varieties, and not for hybrid varieties. Due the biology of open-pollinated 

varieties, these types of plants may be more receptive to pollen over a longer period of time 

than hybrid corn plants (Sanvido, Widmer et al. 2008), allowing for a greater chance of 

pollination events. Thus, the results from Jones and Brooks (1950) may overestimate the 

potential for cross-fertilization of hybrid corn plants. 

No Action: Gene Movement 

Under the No Action Alternative, DP-32138-1 would remain a regulated article and would 

require an APHIS permit or notification for release into the environment. Under regulated 

releases, regulated GE corn is typically separated from non-regulated corn by a distance of 

660ft, based on distances set for seed production (AOSCA 2004), if distance is the only method 

used to prevent movement of pollen or genes. APHIS has concluded this separation distance is 

sufficient to substantially limit gene movement to other corn crops. 

Preferred Alternative: Gene Movement 

In 2009, GE corn was planted on 85% of all corn acres currently in production in the US, and 

has been steadily increasing (USDA-NASS 2009a). Concurrently, organic corn acreage has also 

increased by 9% over the 2 year period from 2005 to 2007 (USDA-ERS 2010a). Separation 

between the two types of corn varieties has been maintained by means of only recommended 

practices for organic growers and no mandated requirements for GE corn. Production of both 

organic and conventional corn will likely continue to increase with or without a determination of 

nonregulated status of DP-32138-1. 
51

In agricultural systems, growers may choose to grow GE or non-GE corn, and obtain price 

premiums for growing these varieties of corn for particular markets (e.g., using organic methods 

for corn production or producing a specialty corn variety for particular processing needs). For 

example, in 2007, conventional corn averaged $4.19/bushel (USDA-NASS 2010b), whereas 

organic corn averaged $7.08/bushel (USDA-NASS 2010c). USDA asserts that agricultural 

practices that use conventional means, with GE or non-GE varieties, and organic production 

systems can all provide benefits to the environment, consumers, and farm income. Gene 

movement into and out of these specialized corn production systems have been managed 

using various types of buffer zones or isolation practices, such as differences in planting (which 

results in differences in flowering) or making sure fields are sufficiently distant from other 

compatible crops (such as using appropriate isolation distances). 

In addition to the typical identity preservation and closed loop systems in place for specialty 

crops, those farmers using organic production also put into place measures to maintain purity 

of their crops. Typically, more than one method is used by farmers under organic production 

rules 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, 

and formal communications between neighboring farms (NCAT 2003). The plan used as the 

basis for organic certification should include a description of practices used to prevent or 

reduce the likelihood of unwanted substances, like GE pollen or seed, at each step in the 

farming operation, such as planting, harvesting, storing and transporting the crop (Riddle 2004; 

Krueger 2007; Kuepper, Born et al. 2007). Practical methods typically used by corn farmers will 

protect their crop and maximize their profits and premiums. The financial benefits accrue to 

organic corn produced using approved plans that are also successfully accomplished. For 

example, farmers using organic methods are requested to let neighboring farmers know that 

they are using organic production practices and request that the neighbors also help the farmer 

reduce contamination events (NCAT 2003; Krueger 2007). Thus, commonly used organic 

production practices for corn currently provide many measures that greatly reduce the likelihood 

of accidental gene flow. In addition, pollen containing the SPT transgene is not fertile, and gene 

flow between DP-32138-1 and non-GE corn fields is highly unlikely. 

DP-32138-1 would be an additional GE corn variety that may be available to the seed 

production industry. The production area for DP-32138-1 seed is likely limited to less than 

5000 acres if SPT is utilized only by Pioneer or no more than 20,000 acres if SPT is licensed 

to all seed corn producers in the U.S. Overall impacts of gene movement would be similar to 

the No Action Alternative.

Cumulative Effect: Gene Movement 

DP-32138-1 would be an additional technology that may be available to the seed corn industry. 

The production area for DP-32138-1 seed is likely limited to less than 5000 acres if SPT is used 

only by Pioneer or no more than 20,000 acres if SPT is licensed to all seed corn producers in 

the U.S. The production of conventional, GE and organic corn is expected to continue. GE and 

organic acreage currently coexist, and there is no change in this coexistence with DP-32138-1 

corn. The potential for movement of transgenes from GE crops into non GE varieties is not 

expected to change as a result of approving DP-32138-1. 
52

Public Heath 

Human Health 

Under the FFDCA, it is the responsibility of food and feed manufacturers to ensure that the 

products they market are safe and properly labeled. Food and feed derived from DP-32138-1 

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. 

No Action: Human Health 

The FDA considers Pioneer's consultation on DsRed2 color marker protein, the only non-native 

corn protein in DP-32138-1 corn, and the consultation on the alpha-amylase ZM-AA1 to be 

complete (Appendix A). The status of the FDA consultation will not change under the No 

Action Alternative. 

Preferred Alternative: Human Health 

DP-32138-1 is genetically engineered to contain a sequence of DNA with three genes, Ms45, 

zm-aa1, and DsRed2 (Alt1). Ms45 is a corn gene that encodes the MS45 protein required for 

the production of fertile pollen and is controlled by a corn anther preferred promoter 5126. 

zm-aa1 is a corn gene that encodes the ZM-AA1 alpha-amylase protein, which breaks down 

starch (Janeček 1994). zm-aa1 is controlled by a corn polygalacturonase promoter (Pg47) that 

targets expression to pollen (Allen and Lonsdale 1993). When the ZM-AA1 protein is expressed 

in immature pollen, the depletion of starch reserves renders the pollen infertile. The DsRed2

gene is from a marine coral-like anemone Discosoma sp. (Matz, Fradkov et al. 1999; WassonBlader 2001) that was modified by a single base pair substitution to produce DsRed2(Alt1). 

The lipid transfer protein (Ltp2) promoter from barley targets expression to the aleurone layer of 

the seed (Kalla, Shimamoto et al. 1994). DP-32138-1 seeds expressing the DsRed2 color marker 

protein are colored pinkish-red, which will enable detection and sorting of transgenic red corn 

seeds from non-transgenic yellow seeds using a color sorting machine (Wasson-Blader 2001; 

Pioneer 2009). 

The MS45 protein is a native corn fertility gene. The MS45 protein in DP-32138-1 was found 

only in the developing anther tissues during early pollen formation, the same location as 

conventional corn, and was not found in later stages of pollen formation or in other parts of the 

plant (Pioneer 2009). Pioneer also submitted to APHIS information on identity, function, 

characterization of genes, expression levels of gene products, as well as information on the 

potential allergenicity and toxicity of the expressed MS45 protein. APHIS’ assessment of the 

safety of this product for humans and animals focuses on plant pest risk (USDA-APHIS 2010) 

and effects on wildlife and threatened and endangered species (section on Animals and 

Threatened and Endangered Species), and those analyses are based on the comparison of the 

GE-corn to its non-GE counterpart. No new issues appear to be associated with the Ms45

transgene in DP-32138-1 corn. 

In conventional corn, the alpha-amylase protein is expressed predominantly in the scutellum of 

germinating seed and minimal expression is observed in the developing endosperm. The 

endogenous corn alpha-amylase protein cannot be detected in non transformed corn pollen 

(Pioneer 2009). Alpha-amylases are ubiquitous in the environment, being naturally present in 
53

microorganisms, plants and animals (Janeček, Lévêque et al. 1999). Many types of commercial 

food processing, feed ingredient applications, and industrial applications also utilize alphaamylase enzymes, including the production of fuel and potable alcohol (brewing, distillation 

processes), and corn syrups (Janeček, Lévêque et al. 1999; Lévêque, Janeček et al. 2000; Pariza 

and Johnson 2001; Olempska-Beer, Merker et al. 2006). 

In DP-32138-1 corn, the ZM-AA1 protein is additionally found in the developing pollen and at 

low levels in other parts of the plant except at physiological maturity when it is below levels of 

quantitation (Pioneer 2009). Since the ZM-AA1 protein in DP-32138-1 is found in a new tissue 

location in corn, a new protein consultation was submitted to the FDA. Pioneer provided the 

FDA with information on identity, function, and characterization of the genes, as well the 

expression levels of the gene products. They also provided information on the potential 

allergenicity and toxicity of the expressed proteins. The FDA considers Pioneer's consultation on 

ZM-AA1 alpha-amylase protein to be complete (Appendix B). Pioneer also submitted 

information on identity, function, characterization of genes, expression levels of gene products, as 

well as information on the potential allergenicity and toxicity of the expressed proteins to 

APHIS. APHIS’ assessment of the safety of this product for humans and animals focuses on 

plant pest risk (USDA-APHIS 2010) and effects on wildlife and threatened and endangered 

species (section on Animals and Threatened and Endangered Species). These analyses are based 

on the comparison of the GE-corn to its non-GE counterpart. No new issues appear to be 

associated with the zm-aa1 transgene in DP-32138-1 corn. 

The DsRed2 color marker protein is the only expressed transgenic protein in DP-32138-1 not 

derived from corn. In physiologically mature plants of DP-32138-1 corn, the DsRed2 protein is 

found in the seed, but not in leaves or pollen. In the growing plant, however, it is found in leaves 

(Pioneer 2009). Pioneer provided the FDA with information on identity, function, and 

characterization of the genes, as well the expression levels of the gene products. They also 

provided information on the potential allergenicity and toxicity of the expressed proteins. The 

FDA considers Pioneer's consultation on DsRed2 protein in DP-32138-1 to be complete 

(Appendix A). Pioneer also submitted information on identity, function, characterization of genes, 

expression levels of gene products, as well as information on the potential allergenicity and 

toxicity of the expressed proteins to APHIS. APHIS’ assessment of the safety of this product 

for humans and animals focuses on plant pest risk (USDA-APHIS 2010) and effects on wildlife 

and threatened and endangered species (section on Animals and Threatened and Endangered 

Species), and those analyses are based on the comparison of the GE-corn to its non-GE 

counterpart. No new issues appear to be associated with the DsRed2 (Alt1) transgene in DP32138-1 corn. 

Based on the assessment of laboratory data provided by Pioneer in the submitted petition and an 

analysis of the scientific literature (USDA-APHIS 2010), along with the completion of the 

consultation process with FDA regarding DsRed2 color marker protein in DP-32138-1 

(Appendix A), APHIS has concluded that under this alternative, the proposed action to approve 

nonregulated status for DP-32138-1 would have no significant impacts on human or animal 

health. 

Cumulative Effects: Human Health 
54

There are no significant impacts on human or animal health related to the No Action Alternative 

or a determination of nonregulated status of DP-32138-1 corn, and no cumulative effects have 

been identified. 

Worker Safety 

No Action: Worker Safety 

During agricultural production of corn, farmers may be exposed to pesticides during application 

of these chemicals to crops. Under the No Action Alternative, exposure to these agricultural 

chemicals during corn production would remain the same. Under the No Action Alternative, 

workers continue to be exposed to safety hazards associated with farm equipment during 

detasseling operations. 

Preferred Alternative: Worker Safety 

Worker safety issues related to the use of pesticides during agricultural production of DP-32138-1 

would remain the same as the No Action Alternative. As discussed under the issue of 

“Cropping Practices: Crop Rotation, Tillage, Production, and Pesticide Use”, DP-32138-1 does 

not change the agronomic practices, or use of chemicals such as pesticides, associated with seed 

corn production. With DP-32138-1, detasseling would no longer be needed and therefore 

workers would no longer be exposed to safety hazards associated with farm equipment during 

detasseling operations. 

Cumulative Effects: Worker Safety 

Worker safety issues related to agronomic practices and the use of pesticides during agricultural 

production of DP-32138-1 would continue and remain the same under both alternatives. As 

discussed under the issue of “Pesticide Use”, DP-32138-1 does not change the agronomic 

practices, or use of chemicals such as pesticides, associated with seed corn production. With 

DP-32138-1, detasseling would no longer be needed and therefore, workers would no longer be 

exposed to safety hazards associated with farm equipment during detasseling operations. There 

are no cumulative effects identified for this issue. 

Animal Feed 

More than 60 % of the corn produced in the US and much of the exported corn is used for animal 

feed (Hoeft, Nafziger et al. 2000).  Under the FFDCA, it is the responsibility of feed 

manufacturers to ensure that the products they market are safe and properly labeled. Feed 

produced with DP-32138-1 technology must be in compliance with all applicable legal and 

regulatory requirements. GE organisms may undergo a voluntary consultation process with 

the FDA for feed safety prior to release onto the market. 

No Action: Animal Feed 

The FDA considers Pioneer's consultation on DsRed2 color marker protein, the only non-native 

corn protein in DP-32138-1 corn, to be complete (Appendix A). The FDA also considers 

Pioneer's consultation on ZM-AA1 alpha-amylase protein to be complete (Appendix B). This 

native corn protein is normally expressed in germinating seeds but in DP-32138-1 corn the 
55

modified amylase is expressed in the pollen. The status of the FDA consultations will not 

change under the No Action Alternative. 

Preferred Alternative: Animal Feed 

DP-32138-1 is genetically engineered to contain a sequence of DNA with three genes, Ms45, 

zm-aa1, and DsRed2 (Alt1). Ms45 is a corn gene that encodes the MS45 protein required for 

the production of fertile pollen and is controlled by a corn anther preferred promoter 5126. 

zm-aa1 is a corn gene that encodes the ZM-AA1 alpha-amylase protein, which breaks down 

starch (Janeček 1994). For a detailed description of each of gene and its impacts, please refer to 

the Human Health section above. 

The FDA considers Pioneer's consultation on ZM-AA1 alpha-amylase protein in DP-32138-1 to 

be complete (Appendix B). Pioneer also submitted information on identity, function, 

characterization of genes, expression levels of gene products, as well as information on the 

potential allergenicity and toxicity of the expressed proteins to APHIS. APHIS’ assessment of 

the safety of this product for animals focuses on plant pest risk (USDA-APHIS 2010) and 

effects on wildlife and threatened and endangered species (section on Animals and Threatened 

and Endangered Species), and those analyses are based on the comparison of the GE-corn to its 

non-GE counterpart. No new issues appear to be associated with the zm-aa1 transgene in DP32138-1 corn (Pioneer 2009). 

The FDA considers Pioneer's consultation on DsRed2 protein in DP-32138-1 to be complete 

(Appendix A). Pioneer also submitted information on identity, function, characterization of genes, 

expression levels of gene products, as well as information on the potential allergenicity and 

toxicity of the expressed proteins to APHIS. APHIS’ assessment of the safety of this product 

for animals focuses on plant pest risk (USDA-APHIS 2010) and effects on wildlife and 

threatened and endangered species (section on Animals and Threatened and Endangered 

Species), and those analyses are based on the comparison of the GE-corn to its non-GE 

counterpart. No new issues appear to be associated with the DsRed2 (Alt1) transgene in DP32138-1 corn. 

Based on the assessment of laboratory data provided by Pioneer in the submitted petition and 

an analysis of the scientific literature (USDA-APHIS 2010), along with the completion of the 

consultation process with FDA regarding DsRed2 color marker protein in DP-32138-1 

(Appendix A), APHIS has concluded that under this alternative, a determination of nonregulated 

status of DP-32138-1 would have no significant impacts on animal feed, nor on animal health. 

Pioneer has communicated to APHIS (Weber, personal communication) that transgenic seed 

produced with the DP-32138-1 line is not intended for and is not expected to enter the general 

corn commodity supply. The procedures established by Pioneer will effectively prevent 

appearance of the SPT genes in corn commodities unless willful actions are taken to contradict 

company policy and practice. 

Cumulative Effects: Animal Feed 

There are no significant impacts on animal health related to the No Action Alternative or a

determination of nonregulated status of DP-32138-1 corn, and no cumulative effects have been 

identified. 
56

Socioeconomic Issues 

Domestic Economic Environment at Risk 

The U.S. domestic market for seed corn is estimated to be $4.6 billion in 2007 and $5.2 billion in 

2008 based on the estimated seed costs per acre of $49 per acre in 2007 and $60 per acre in 2008 

(USDA-ERS 2010b) and 93.5 million acres planted in 2007 and 86.0 million acres planted in 

2008 (USDA-NASS 2010a). 

The production of hybrid seed requires substantial control over the pollen sources. Detasseling 

is the most common procedure for pollen control. Tassels are removed by hand or by machine; 

both methods are expensive and result in major plant injury with accompanying lower seed 

yields. In 1988, detasseling costs ranged from $100 to $130 per acre (Wych 1988). Much of the 

cost of detasseling is personnel costs. Assuming that detasselers earn approximately minimum 

wages and based on minimum hourly wage rates of $3.35 in 1988 and $7.25 in 2009 (US-DOL 

2010), it can be estimated that 2009 detasseling costs range from $216 to $281 per acre. Yield 

reduction due to detasseling has been estimated to range from 1.5% to 13.5% for hand 

detasseling and 2%-45% for mechanical detasseling (Wych 1988). To estimate cost of yield 

losses caused indirectly by detasseling, several assumptions can be made. For the production of 

any seed that requires detasseling, strict contracts are put in place with farmers who are willing 

to grow the low yielding inbred plants along with the challenges of growing corn to exacting 

planting, growing and harvesting protocols and schedules. In return for the complexity of 

growing seed corn, paying premiums and minimums are standard parts of the contract. The 

minimum standards are likely to be equivalent to the returns that would be expected from 

growing conventional corn, which would be based on the average yields in the area and the 

commodity corn price. For example, the average yield might be 170 bushels with a commodity 

price of $4.00 per acre [yields and prices based on approximate national averages for 2009 

(USDA-NASS 2009a)] making the minimum standard $680 per acre. A 10% yield reduction 

from detasseling is approximately $68 per acre. Total costs of detasseling (cost of detasseling 

plus yield reduction) may be in the range of $280 to $350 per acre. The total industry wide cost 

of detasseling of up to 1 million acres is estimated at approximately $280-350 million. Spreading 

this total cost over 90 million acres of conventional corn production indicates that the detasseling 

costs are approximately $3 to $4 per planted acre of conventional corn production which is 6%- 

8% of the 2007 seed costs and 3%-7% of the 2008 seed costs. 

No Action: Domestic Economic Environment 

Under the No Action Alternative, DP-32138-1 would remain a regulated article and would 

require an APHIS permit or notification for release into the environment. Seed corn production 

methods would be the same as currently used under the No Action Alternative. Manual and 

mechanical detasseling are the major methods for controlling pollen in the hybrid seed corn 

production fields. No effects are anticipated in the commercial production of corn under the No 

Action Alternative. 

Preferred Alternative: Domestic Economic Environment 

Under the Preferred Alternative, the availability of seed corn would be determined by the 

market demand for commercial corn grain as it is under the No Action Alternative. 

However, under the Preferred Alternative, DP-32138-1 could be used to reduce the need for 

detasseling along with the associated cost of detasseling. This could lead to a yield increase due 
57

to a reduction of plant injury caused by mechanical detasseling. The yield increases would reduce 

the total number of acres devoted to seed corn production and would lower overall seed 

production costs. If all 1 million acres of seed increase used DP-32138-1 corn, the cost savings 

from avoiding detasseling operations and associated increased yields would most likely exceed 

$200 million. The estimated cost of detasseling is about $3-$4 per planted acre of conventional 

corn production which is equivalent to yield of about one bushel per acre in conventional corn 

production. 

The cost savings from eliminating detasseling operations would provide seed companies with 

several options. One option is to keep their seed sales price unchanged from previous seasons to 

enhance their profit margin. Another option would be to pass along the entire cost savings by 

reducing the selling price of seed to the farmer. This option may help to gain company market 

share for the company. One other option is to keep the cost savings and invest the money in 

research to make better varieties. The method of dealing with these cost savings, whether it is a 

choice of one of these options or a combination is a business decision. The cost savings for DP32138-1-produced seed corn will potentially be small ones for conventional corn growers, but the 

impact on conventional grain production levels or prices using DP-32138-1 would be smaller still 

and difficult to measure. 

No estimate is available for the level of acceptance, if any, of using DP-32138-1 in seed corn 

production for the applicant or for the industry as a whole. Since 1995, three GE male sterility 

systems for corn have been proposed and deregulated by APHIS, but have not been used 

commercially (Pioneer 2009). Therefore the potential implementation of the commercial use of 

DP-32138-1 technology by the seed corn industry would be speculative. 

The Seed Production Technology is a process that uses the DP-32138-1 SPT insertion to produce 

hybrid seed to contain no transgenes and without need for detasseling. To make male sterile 

inbreds (the female parent for hybrid production), the male fertile SPT maintainer line 

contributes pollen to a male sterile inbred line; virtually all SPT containing pollen grains are 

inviable, and thus will not be transferred to the seed for the male sterile female parent. 99.999% 

of seed from this cross is lacking the SPT insert. To eliminate any possible transgenic SPT seed, 

this seed is passed twice through a seed sorter (with an accuracy of detection of 99.95%). Two 

steps, non-transgenic pollen shed and seed sorting, result in a process that produces male sterile 

female inbreds that are predictably and reliably transgene free. These plants are then used by 

contract seed growers to produce commercial seed. 

Production of the DP-32138-1 SPT maintainer line and production of the female inbred parent 

lines (Step I and II of Figure 1,) would be accomplished at Pioneer-controlled field sites or on 

those sites of other companies having rights to the technology (should Pioneer choose to license 

it). Thus, the transgenic lines would be under the continuous control of a seed technology 

provider. After each of these two steps, seed would be sorted by Pioneer into transgenic and 

non-transgenic seeds, with the discarding of all transgenic, marked seeds after Step II (Figure 1). 

Pioneer demonstrated that the efficiency of the SPT system in producing non transgenic seed was 

>99.999% (Pioneer 2009). The accuracy of the color-based sorting system for transgenic seed 

was >99.95%. Consequently, the likelihood that a transgenic seed would not be removed from 

the Step II selection would be the product of both the accuracy of detection and seed removal 

with the efficiency of the process, which would occur with a frequency approaching zero. One 

additional means of analyzing transgenic content was undertaken. When non transgenic 

machine-identified seed was sorted from marked transgenic seed, and the putative non transgenic 
58

seed was used to grow corn, leaf tissue was analyzed for the presence of transgenes. When DP32138-1 was used as a pollen donor for male sterile female inbred production, seed was collected 

from this cross and sorted twice to remove any remaining DP-32138-1 corn seed. Plants grown 

from the 15,000 collected seed were analyzed using PCR techniques; none of the plants 

contained genes derived from the SPT insertion (Pioneer 2009). 

The non-transgenic seed derived from the Step II increase (Figure 1) would be used to provide 

the male-sterile female plants for hybrid production. Although the DP-32138-1 line is genetically 

engineered, the progeny of DP-32138-1 that would be grown in Step III (last major increase 

before planting commercial grain fields) along with Step IV (commercial grain production) 

would reliably and predictably yield non-transgenic seed. The final phase of seed production, 

Step III, would typically be accomplished by contract growers, whose non-transgenic seed would 

be sold to seed suppliers for commercial production. 

No information was found to determine whether growers and consumers of non-GE or organic 

corn would accept corn derived through GE technology, but now containing no transgenes. 

Therefore, for buyers who desire non-GE corn seed or commodity corn in the US, the marketing 

potential for seed produced from DP-32138-1 is unclear and speculative. 

Cumulative Effects: Domestic Economic Environment 

Assuming complete acceptance of the DP-32138-1 technology, cumulative domestic economic 

effects on seed corn producers would be cost savings of an estimated $200 million per year. 

Because the cost savings for DP-32138-1 seed corn are small with respect to all conventional 

corn production, using DP-32138-1 may have little measurable cumulative impact on 

conventional grain production levels or prices. 

Trade Economic Environment at Risk 

Seed corn and commercial corn grain are both major exports for the U.S. In 2005 (the most 

recent date with specific information on seed corn) seed corn exports totaled $136 million 

(USDA-FAS 2005). Corn is exported in bulk, as corn by-products, and feed. Since corn is used 

heavily as an animal feed for poultry, hogs and cattle, export of animal products could also be 

considered as related to corn production. Export of corn grain in bulk was $8.8 billion in 2009, 

$13.4 billion in 2008, and $9.8 billion in 2007 (USDA-ERS 2010c). Foreign customers in 

Europe and Japan may have concerns with a new variety of GE grain and new GE traits must 

undergo extensive regulatory assessment before they are approved for import (USGC 2006). 

No Action: Trade Economic Environment 

The availability of methods used to produce seed corn would be the same as currently used in 

seed corn production systems with detasseling being a major method for controlling pollen in 

the hybrid seed corn production fields. Since crop production practices are not anticipated to 

change, no effects are anticipated in the commercial production of corn under the No Action 

Alternative. 

Preferred Alternative: Trade Economic Environment 

Under the Preferred Alternative, the total supply of seed corn would be determined by the 

international market demand for commercial corn grain as it is under the No Action 
59

Alternative. However, under the Preferred Alternative, DP-32138-1, savings would accrue to 

the seed producers in reducing resource outlays, and total cost of production and increasing seed 

crop yields (see discussion in preceding section, Preferred Alternative: Domestic Economic 

Environment). The level of acceptance of the technology is not easily predicted (see 

discussion in preceding section, Preferred Alternative: Domestic Economic Environment) 

which makes potential for impacts on trade unclear. Another difficulty is determining how 

international consumers and regulatory frameworks would categorize corn produced with GE 

technologies but now containing no transgenes. If DP-32138-1 is used to produce seed corn for 

export to those regions and countries with rigorous regulatory regimes, the potential impacts for 

international marketing of seed produced with DP-32138-1 is unclear and acceptance would be 

speculative. Because use of the DP-32138-1 cannot be detected or otherwise established in 

commercial corn seed, it is possible that use by seed providers would cause no impacts. Because 

export of seed corn is an important market for US companies, these providers would likely need 

to negotiate seed availability using the technology with international customers and regulatory 

systems well in advance of future sales abroad. Because use of the technology is elective, and 

seed providers could negotiate acceptance of the technology with these customers and regulatory 

systems, the potential impact of DP-32138-1 is not likely to be significant. 

Cumulative Effects: Trade Economic Environment 

There are no likely cumulative effects identified for this issue. Because the cost savings for 

DP-32138-1 seed corn are so small with respect to total conventional corn production, using DP32138-1 may have little measurable impact on conventional grain production levels or prices for 

the international commodity markets. 

Social Environment at Risk from Seed Production Activities 

Conventional seed corn production relies heavily on detasseling as the method for pollen control 

and often rely heavily on thousands of field workers to accomplish this operation (Pioneer 2007). 

Detasseling jobs provide a source of income, but also has the potential to expose workers to 

safety risks associated with the use of heavy machinery used for seed corn detasseling 

operations. 

No Action: Social Environment 

The availability of agricultural methods used to produce seed corn would be the same as currently 

used in seed corn production systems under the No Action Alternative with detasseling being a 

major method for controlling pollen in the hybrid seed corn production fields. Detasseling 

operations would continue to primarily rely on thousands of field workers. Potential economic 

impacts would be unchanged. 

Preferred Alternative: Social Environment 

Under the preferred alternative, DP-32138-1 would be deregulated. If this technology is 

accepted commercially, all seed corn production acres that use this technology would no longer 

require detasseling as the method for pollen control. Depending on the level of acceptance by the 

seed corn production industry, field workers would no longer have detasseling as a possible 

source of income. The possible economic effects of losing these temporary jobs are unclear, but 

it is reasonable to assume that it would have a potential negative impact until another source of 

income could be secured. 
60

Cumulative Effects: Social Environment 

Depending on the level of acceptance by the seed corn production industry, thousands field 

workers would no longer have detasseling as a possible source of income. This impact is 

expected to be only a short term one as these workers secure other sources of income to replace 

those incomes lost. 

Other Cumulative Effects 

All potential cumulative effects regarding specific issues have been analyzed and addressed 

above. No further potential cumulative effects have been identified. Stacked varieties, those 

crop varieties that may contain more than one trait, are currently found in the marketplace and in 

agricultural production. In the event of a determination of nonregulated status of DP-32138-1, 

DP-32138-1 may be used to combine with non-GE and GE corn varieties by traditional 

breeding techniques, resulting in hybrids that, for example, may also be resistant to herbicides 

or insects. The resulting hybrids would not contain the SPT transgene. 

APHIS’ regulations at 7 CFR Part 340 do not provide for Agency oversight of GE corn varieties 

previously deregulated pursuant to Part 340 and the Plant Protection Act, nor over stacked 

varieties combining deregulated GE varieties unless it can be positively shown that such 

stacked varieties were to pose a likely plant pest risk. To date, none of the GE corn varieties 

that have been deregulated pursuant to Part 340 and the Plant Protection Act and used for 

commercial breeding program have been subsequently found to pose a plant pest risk. 

There is no guarantee that DP-32138-1 will be stacked with any particular deregulated GE 

variety, as company plans and market demands play a significant role in those business 

decisions. Moreover, DP-32138-1 could even be combined with non-GE corn varieties. Thus, 

predicting all potential combinations of stacked varieties that could be created using both 

deregulated GE corn varieties and also non-GE corn varieties is hypothetical and purely 

speculative. 

Threatened and Endangered Species 

APHIS analyzed the potential for effects from cultivation of DP-32138-1 and its progeny on 

federally listed threatened and endangered species (TES) and species proposed for listing, as well 

as designated critical habitat and habitat proposed for designation, as required under Section 7 

of the Endangered Species Act. Direct effects are analyzed by considering the response that 

TES could have if exposed to DP-32138-1 corn. Indirect effects are those that could result from 

the use of DP-32138-1 in corn production, would occur later in time, but are still reasonably 

certain to occur. Consideration is given for the potential of DP-32138-1 to change the baseline 

habitat of TES including critical habitat. If the analysis determines that a determination of 

nonregulated status of DP-32138-1 may affect listed species or critical habitat, consultation 

with the United States Fish and Wildlife Service (USFWS) or the National Marine Fisheries 

Service (NMFS) is required. 

DP-32138-1 was developed solely to be used to produce male sterile inbred plants for the 

generation of hybrid corn seed that is not transgenic (Pioneer 2009). The carefully controlled 

expression of a seed color marker gene and pollen fertility and sterility genes allows for the 

generation of red transgenic seed for seed increase of male sterile-female inbred lines that are 

used in non transgenic hybrid commercial seed. DP-32138-1 contains a DNA insert with three 
61

genes- a male fertility gene, Ms45, from corn; an alpha-amylase gene, zm-aa1, from corn; and 

a fluorescent color marker protein gene, DsRed2(Alt1), from a marine coral Discosoma sp., the 

only gene not native to corn. 

DP-32138-1 is not genetically engineered to produce a toxin or pesticide, and is not 

genetically engineered to be tolerant to an herbicide. A NPC for the DsRed2 protein color 

marker was submitted to FDA on October 11, 2006 with the follow up letter of January 9, 2010 

received from FDA (Appendix A). The FDA considers Pioneer's consultation on ZM-AA1 

alpha-amylase protein to be complete (Appendix B).

If the seed corn industry completely converts to using this technology, the DP-32138-1 would 

be grown on a maximum of 20,000 acres (the total area currently used for corn seed production 

and 0.02% of all corn production acres in the U.S.). These 20,000 acres would likely be the 

same 20,000 acres used in conventional seed corn production that have been in agricultural 

production for many years. The same agronomic practices for conventional seed corn 

production would be used for DP-32138-1 production - including the same fertilizers, 

herbicides, fungicides, insecticides, irrigation, crop rotations, and tillage. Corn seed for 

planting produced using DP-32138-1 and the plants grown from these seed no longer have any 

of the transgenes. Therefore, the maximum exposed area is up to 20,000 acres in locations 

where agricultural seed corn production has historically occurred. There is no hazard 

associated with producing corn seed using the DP-32138-1 technology that would be different 

from production of conventional corn. 

Corn is a feed commonly provided to many livestock and wildlife (e.g., birds, deer, and 

rodents). To identify the direct effects on listed animal species that could result from feeding, 

APHIS compared the composition and nutritional quality of DP-32138-1 corn, with a nongenetically engineered control corn line and the natural variation found in two commercial 

corn inbred lines. If the composition of DP-32138-1 inbred is similar to other commercial corn 

inbred plants, it is unlikely that DP-32138-1 would affect listed animal species, regardless of 

exposure. 

The data presented in the petition suggests there is no difference in compositional and nutritional 

quality of DP-32138-1 compared to conventional corn, apart from the presence of DsRed2 

protein (MS45 protein and ZM-AA1 alpha-amylase protein are both found in conventional corn). 

Although some of the variables measured by the applicant showed statistically significant 

differences between DP-32138-1 corn and the nontransgenic inbred controls (Pioneer 2009), 

none of the values for the grain composition characteristics were outside the range of natural 

variability of conventional corn as found in the International Life Sciences Institute Crop 

Composition Database (OECD 2003; Ridley, Shillito et al. 2004; ILSI 2008) or in the OECD 

consensus document on corn composition (OECD 2003). DP-32138-1 does not express 

additional proteins, natural toxicants, allelochemicals, pheromones, hormones, etc. that could 

directly or indirectly affect a listed TES or species proposed for listing. A toxicological safety 

assessment conducted on DsRed2 protein showed that it is unlikely to be a toxin or have any 

relevant similarities to known or putative allergens (Pioneer 2009). Thus, the composition and 

nutritional quality of DP-32138-1 is not biologically different than conventional corn, and would 

not be expected to affect TES differently. 

Corn itself is not sexually compatible with any listed plant species; therefore there is no 

potential for a direct effect of DP-32138-1 on TES plants. Indirect effects of DP-32138-1 on 
62

listed plant species were also evaluated. Corn does not have sexually-compatible relatives 

found in ‘natural’ areas; corn is only able to reproduce with other corn plants in the U.S. 

(OECD 2003). As stated above, DP-32138-1 will have no effect on animals, including animals 

such as insects, bats or birds that may be pollinators of TES plants. Because corn cannot 

naturalize and would not affect pollinators, there are no expected indirect effects of DP32138-1 on TES plants. 

Cultivation of DP-32138-1 is not expected to differ from practices normally used for seed corn 

production or commercial corn production. DP-32138-1 corn plants with transgenes are 

expected to be grown only on a maximum of 20,000 acres (0.02% of all corn produced in the 

USA) and is expected to replace only conventional corn varieties currently grown for seed. The 

potential environmental impacts on TES from this product are those associated with typical 

corn seed production and commercial corn production, in areas where corn seed and 

commercial corn are typically produced, and therefore would not affect the baseline habitat of 

any listed species. 

After reviewing possible effects of a determination of nonregulated status of DP-32138-1 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 has considered the effect of DP-32138-

1 production on designated critical habitat or habitat proposed for designation and could 

identify no difference from effects that would occur from the seed production of other corn 

varieties. Therefore, APHIS has reached a conclusion that the release of DP-32138-1 corn, 

following a determination of nonregulated status, would have no effect on federally listed 

threatened or endangered species or species proposed for listing, nor would it affect designated 

critical habitat or habitat proposed for designation. Consequently, consultation with the USFWS 

or NMFS is not required for this action. 

Consideration of Executive Orders, Standards and Treaties Relating to Environmental 

Impacts 

Executive Order (EO) 12898 (US-NARA 2010), “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 or low-income communities from being subjected to disproportionately high 

and adverse human health or environmental effects. EO 13045 (US-NARA 2010), “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) 

required each Federal agency to identify, assess, and address environmental health risks and 

safety risks that may disproportionately affect children. 

Each alternative was analyzed with respect to EO 12898 and 13045. Based on the 

information submitted by the applicant and assessed by APHIS, DP-32138-1 is not 

significantly different than conventional corn production. FDA has reviewed the introduced 

proteins (DsRed2 and ZM-AA1) in the unlikely case that the Event may inadvertently enter 
63

the commodity grain stream. Pioneer concluded that the proteins were safe for food and feed 

use (Pioneer 2009) and FDA agreed that the presence of the proteins would not lead to safety 

concerns when present in low levels in the food supply. Therefore, DP-32138-1 is not 

expected to have a disproportionate adverse effect on minorities, low-income populations, or 

children. Based on historical experience with corn production and the data submitted by the 

applicant and assessed by APHIS, DP-32138-1 should eliminate the need for detasseling, 

which in turn would increase worker safety by significantly reducing the number of 

seasonal workers exposed to the hazards of working around heavy farm machinery. 

EO 13112 (US-NARA 2010), “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. Both non-GE 

and GE corn varieties that have been previously deregulated pursuant to Part 340 and the Plant 

Protection Act are widely grown in the U.S. Based on historical experience with corn and the 

data submitted by the applicant and assessed by APHIS, DP-32138-1 plants are very similar in 

fitness characteristics to other corn varieties currently grown and are not expected to become 

weedy or invasive (USDA-APHIS 2010). 

EO 13186 (US-NARA 2010), “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 2 years, a 

Memorandum of Understanding (MOU) with the Fish and Wildlife Service that shall promote 

the conservation of migratory bird populations. Data submitted by the applicant has shown no 

difference in compositional and nutritional quality of DP-32138-1 compared to conventional 

corn, apart from the presence of DsRed2 protein. The migratory birds that occasionally forage in 

corn fields are unlikely to contain high amounts of DP-32138-1 as corn grain availability is 

limited by seed germination and harvest. Based on APHIS’ assessment of DP-32138-1 it is 

unlikely that a determination of nonregulated status of this corn variety will have a negative 

effect on migratory bird populations.

Impacts on Unique Characteristics of Geographic Areas. 

There are no unique characteristics of geographic areas such as park lands, prime farm lands, 

wetlands, wild and scenic areas, or ecologically critical areas that would be adversely impacted 

by a determination of nonregulated status of DP-32138-1 corn. The common agricultural 

practices that would be carried out under the proposed action will not cause major ground 

disturbance, do not cause any physical destruction or damage to property, do not cause any 

alterations of property, wildlife habitat, or landscapes, and do not involve the sale, lease, or 

transfer of ownership of any property. This action is limited to a determination of nonregulated 

status of DP-32138-1 corn. The product will be deployed on a limited number of acres of 

agricultural farm land used for corn seed production which may be focused in a small number of 

sites where Pioneer and future potential licensees may produce seed corn, but potential for such 

production may exist where corn is grown in all US states, except Alaska. Progeny of this variety 

that express the identified traits of the DP-32138-1 corn will be retained by Pioneer or licensed 

users, and those progeny derived from production of hybrid commercial corn will be predictably 

and reliably without transgenes. This action would not convert land use to nonagricultural use 

and therefore would have no adverse impact on prime farm land. Standard agricultural practices 

for land preparation, planting, irrigation, and harvesting of plants would be used on agricultural 

lands planted to DP-32138-1 corn including the use of EPA registered herbicides. Applicant’s 
64

adherence to EPA label use restrictions for all pesticides will mitigate potential impacts to the 

human environment. In the event of a determination of nonregulated status of DP-32138-1 corn, 

the action is not likely to affect historic or cultural resources, park lands, prime farmlands, 

wetlands, wild and scenic rivers, or ecologically critical areas that may be in close proximity to 

corn production sites.

International Implications 

EO 12114 (US-NARA 2010), “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 due consideration and does not expect a significant environmental impact outside the U.S. in 

the event of a determination of nonregulated status of DP-32138-1 corn. It should be noted that 

all the considerable, 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. Any 

international trade of DP-32138-1 subsequent to a determination of nonregulated status for 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 set 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 pest 

risk analysis (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 genetically 

engineered 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. 

Compliance with Clean Water Act and Clean Air Act 

This EA evaluated the changes in corn production due to the unrestricted use of DP-32138-1 corn. 

DP-32138-1 will not lead to the increased production of corn in U.S. agriculture. There is no 

expected change in water use due to the production of DP-32138-1 compared to current corn 

seed production regimes, nor is it expected that air quality will change because of 

production of DP-32138-1. 

National Historic Preservation Act (NHPA) of 1966 as Amended 
65

The NHPA of 1966, and its implementing regulations (36 CFR 800), requires Federal agencies 

to: 1) determine whether activities they propose constitute "undertakings" that has 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. 

A determination of nonregulated status of DP-32138-1 corn will not adversely impact cultural 

resources on tribal properties. Any farming activities that may be taken by farmers on tribal 

lands are only conducted at the tribe’s request; thus, the tribes have control over any potential 

conflict with cultural resources on tribal properties. 

A determination of nonregulated status of DP-32138-1 corn 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 they likely cause any loss or destruction of significant scientific, 

cultural, or historical resources. This action is limited to a determination of non-regulated status 

of DP-32138-1 corn. Standard agricultural practices for land preparation, planting, irrigation, 

and harvesting of plants would be used on these agricultural lands including the use of EPA 

registered pesticides. Applicant’s adherence to EPA label use restrictions for all pesticides will 

mitigate impacts to the human environment. 

A determination of nonregulated status of DP-32138-1 corn 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 audible 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 audible effects 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 DP-32138-1 corn does not inherently 

change any of these agronomic practices so as to give rise to an impact under the NHPA. 

V. References

Agarwala, S. C., P. N. Sharma, et al. (1981). "Development and enzymatic changes during pollen 

development in boron deficient maize plants." Journal of Plant Nutrition 3: 329-336. 

 

Albertsen, M. C., T. W. Fox, et al. (1993). "Tagging, cloning, and characterizing a male fertility 

gene in maize." American Journal of Botany Suppl 80: 16. 

 

Allen, R. L. and D. M. Lonsdale (1993). "Molecular characterization of one of the maize 

polygalacturonase gene family members which are expressed during late pollen germination." 

Plant Journal 3(2): 261-271. 

 

Aneja, V. P., W. H. Schlesinger, et al. (2009). "Effects of Agriculture upon the Air Quality and 

Climate: Research, Policy, and Regulations." Environ. Sci. Technol. 43: 4234–4240. 

 
66

AOSCA (2004). Association of Official Seed Certifying Agencies Operational Procedures, 

Association of Official Seed Certifying Agencies. 

 

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VI. Appendix A 
78

VII. Appendix B 

 
79

VIII. Appendix C 

Description of Seed Production Technology (SPT) 

(from Pioneer 2009; all figure and table references are to the Petition figures and tables) 

I. Introduction to Seed Production Technology (SPT)

I-B. Maize Hybrid Seed Production 

Hybrid maize (Zea mays L.) is grown on more than 80 million acres in the United States (USDANational Agricultural Statistics Service (NASS), 2008), making it the largest producer of hybrid 

maize. The seed used to produce hybrid maize is generated by crossing two unique inbred 

parental lines referred to as the ‘male inbred parent’ (the plant that is the pollinator) and ‘female 

inbred parent’ (the plant on which the seed is produced). 

For inbred parent seed increase, male and female inbred parental lines are grown separately and 

allowed to self-pollinate in Pioneer fields that are reproductively isolated from other maize plants 

in order to maintain genetic purity and increase the quantity of the inbred parents (Figure 1). In 

order to produce hybrid seed, male and female inbred parent lines are inter-planted in adjacent 

rows (e.g., 2 rows male, 4 rows female, 2 rows male) in reproductively isolated contractor fields 

and allowed to open pollinate. 

To produce pure hybrid seed, the male inbred parent must cross pollinate the female inbred 

parent and the female inbred parent must be prevented from self-pollinating. The most common 

practice to accomplish this is to cut off the pollen-bearing tassels (i.e., detasseling) on the female 

inbred parent (Figure 1). 

In the hybrid seed production fields, the ears of the detasseled female inbred parent can only be 

fertilized with pollen from the male inbred parent planted in adjacent rows. The male inbred 

parent is removed from the fields before the ears reach maturity. Thus, the seed produced on the 

female seed parent will be uniformly hybrid. The F1 hybrid seed is harvested, cleaned, 

conditioned, and bagged for sale to growers. When planted in growers’ fields, the hybrid seed 

will produce a uniform F1 crop. The grain harvested from growers’ fields is used for feed and 

fuel production, processed into food products and industrial materials, or exported. 

I-C. Maize Fertility Control in Hybrid Maize Production 

I-C.1. Detasseling 

The physical removal of the pollen-producing tassels (detasseling) has been the most widely 

used method of preventing female inbred parent self-pollination since maize hybrids were first 

produced in the 1920s (Wych, 1988). Less common or experimental methods include the 

application of chemical sterilants, the use of biological systems based on cytoplasmic malesterility, and systems to control male-fertility using biotechnology (Refer to Appendix 1 for 

additional information on these systems). 

Detasseling can be accomplished manually or mechanically with tassel-cutting or tassel-pulling 

machines. Thousands of temporary workers are employed to detassel maize hybrid seed 

production fields. The detasseling process is not entirely reliable, and on occasion a female plant 
80

will escape complete detasseling. For example, natural variation in plant development can result 

in the emergence of tassels after the detasseling process is complete or a mechanical detasseler 

can fail to remove a tassel completely. Incomplete detasseling results in pollen shed by the 

female inbred parent plant and self-pollination. When this occurs, seed of the female inbred 

parent is harvested along with the hybrid seed which results in reduced seed quality, lowered trait 

purity, and lost yield potential. Mechanical detasseling is faster than hand detasseling, but causes 

more damage to the plants and results in up to 40% reduction in seed yield (Wych, 1988). Today, 

a combination of mechanical and hand detasseling is often used; no form of detasseling is 

entirely satisfactory. Therefore, a need exists for an alternative method of pollen control that is 

safe, efficient, and highly effective. 

I-C.2. Genetic Male-Sterility 

Male-sterility in maize refers to the failure to produce functional pollen. Male-sterile maize 

plants can neither self-pollinate, nor sib-pollinate neighboring plants and can serve as female 

inbred parents in the production of hybrid maize seed. Male-sterility traits display either nuclear 

(also known as genetic) or cytoplasmic inheritance (Refer to Appendix 1 for details). 

Genetic male or pollen sterility in maize was first described by Eyster (1921) that it is due to a 

single recessive gene, designated as ms. Since then, many different genetic male-sterility loci 

have been identified in maize. The chromosome number and map position of nearly all presently 

identified male-sterility genes are well characterized (Neuffer et al., 1997). Sterility phenotype is 

determined by a single gene and the allele for male-sterility is recessive (ms), although a small 

number of dominant male-sterile alleles have been described (Neuffer et al., 1997). In maize, a 

male-sterility plant trait is expressed only by maintenance of a homozygous recessive (ms/ms) 

condition for the fertility gene. 

Limitations to the Use of Homozygous Recessive (ms/ms) Lines as Male-Sterile Parents 

Increase of male-sterile (ms/ms) inbred parent seed is not possible via self-pollination as the 

homozygosity of the recessive gene (ms) results in male-sterility. 

One way to increase the seed of the male-sterile inbred parent is to cross-pollinate male-sterile 

plants (ms/ms) with male-fertile plants which are heterozygous for the male-sterility gene 

(Ms/ms). The progeny from such a cross-breeding are approximately fifty percent male-sterile 

(ms/ms) and fifty percent male-fertile (Ms/ms). Since the male-sterile seed can not be separated 

from the male-fertile seed, this is not a practical way to increase the male-sterile parent seed. 

Recovery and maintenance of pure male-sterile (ms/ms) inbred populations using traditional 

breeding methods requires: a) additional maize lines for the maintenance of the male-sterility 

trait, and b) several intermediate crosses and selection methods that are time consuming. 

Therefore, it is not practical for use in commercial hybrid maize production. 

Thus, a need exists for a convenient and effective process for generating male-sterile inbred 

female parent lines. 

I-C.3. Basis for the Development of Seed Production Technology 
81

Section I-C.2 described how cross-pollinating the male-sterile (ms/ms) plants with heterozygous 

(Ms/ms) male-fertile plants yields a mix of male-sterile and male-fertile genotypes. However, if 

all pollen containing the fertility restoration gene (Ms) could be eliminated from the 

heterozygous male parent (Ms/ms) thereby ensuring pollination of male-sterile (ms/ms) parent 

only with pollen carrying the recessive ms allele, the male-sterile progeny would retain their 

homozygous (ms/ms) condition and could be used as male-sterile female inbred parent in hybrid 

seed production. This is the basis for the Pioneer Seed Production Technology (SPT) process 

utilizing a transgenic 32138 SPT maintainer (Figure 2). 

Pioneer’s novel SPT process generates male-sterile female inbred parent lines that maintain the 

homozygous recessive state (ms/ms) without any intermediate crosses. Male-sterile female 

inbred parent seed can be multiplied, while maintaining the homozygous recessive state of the 

male-sterility gene and providing for full restoration of fertility in the F1 hybrid plants grown in 

commercial fields. 

Figure 2. Schematic Diagram of the Basis for SPT

‡ = Represents 32138 SPT maintainer. 

The SPT construct containing three gene cassettes [Ms45, zm-aa1, and DsRed2(Alt1)] was 

inserted into a male-sterile maize line that is homozygous recessive for ms45 (ms45/ms45) 

shown as ms/ms in Figure 2. The SPT insertion was integrated in the genome at a locus that 

segregates independently from the endogenous ms45 locus (data not shown). Therefore, 32138 

SPT maintainer is homozygous for the ms45 recessive allele and hemizygous for the 

recombinant Ms45 gene from the SPT insertion, indicated as Ms/- in Figure 2. A single copy of 

Ms45 gene from the 32138 SPT insertion restores fertility in the male-sterile (ms45/ms45) line 

(Figure 7B). 32138 SPT maintainer sheds two different types of pollen in a 1:1 ratio: a) nontransgenic fertile pollen (with the ms45 allele) that do not contain the SPT insertion, and b) 

transgenic infertile*

 pollen (with both the ms45 allele and the transgenic Ms45 allele) that contain 

the 32138 SPT insertion (Figure 5). The transgenic pollen carrying Ms45 are rendered infertile 

due to the α-amylase gene (Refer to Sections 1-D and 1-H.2 for more details) in the SPT 

insertion (Figure 9). 

 

*

= Pollen infertility refers to the inability of pollen to germinate and fertilize the ovule. 
82

Therefore, homozygous recessive (ms45/ms45) male-sterile female inbred parent seed can be 

increased by utilizing the pollen from an isogenic SPT maintainer (Figure 3, Step II and Figure 

5). 

I-D. Description of the SPT Process 

Seed Production Technology is a process rather than a trait or a product. The SPT process works 

across all germplasm, requires no detasseling, and produces hybrid seed that are fully fertile. The 

male-sterile female inbred parent increase process is entirely controlled by Pioneer and the total 

acreage in the US planted to the transgenic 32138 SPT maintainer and SPT derived male-sterile 

female inbred parent seed increase each year will be less than 5,000 acres. 

32138 SPT Maintainer 

The SPT process uses a transgenic 32138 SPT maintainer in an ms45/ms45 genetic background 

(Figure 3, Step I). The 32138 insertion in SPT maintainer contains three gene expression 

cassettes essential for the functioning of the SPT system: Ms45, zm-aa1, and DsRed2(Alt1) 

(Figure 6). 

The 32138 SPT maintainer is homozygous for the endogenous ms45 recessive mutant allele and 

hemizygous for the SPT insertion (i.e., ms45/ms45; SPT/-) and therefore contains a single copy 

of the Ms45 gene. Expression of a single copy of Ms45 gene in the ms45/ms45 genetic 

background restores male-fertility and enables pollen production in the 32138 SPT maintainer. 

The 32138 SPT maintainer sheds two different types of pollen in a 1:1 ratio: a) fertile, does not 

contain SPT insertion, and b) infertile, does contain 32138 SPT insertion (Figure 5). Pollen 

containing the 32138 SPT insertion is rendered infertile due to the action of ZM-AA1 α-amylase 

protein. Expression of ZM-AA1 α-amylase in 32138 SPT maintainer pollen results in the 

depletion of starch (Figure 9) and depriving the SPT pollen of the energy reserves required for 

successful pollen germination and fertilization. Hence, any pollen containing the 32138 SPT 

insertion is made infertile. 

A fluorescent color marker (DsRed2(Alt1)) gene is linked to the other two SPT genes (Ms45 and 

zm-aa1) and it confers a pinkish red phenotype to any seed expressing the 32138 SPT insertion 

(Figures 5 and 10). The DsRed2 protein exhibits a high fluorescent intensity and emits a strong 

red fluorescence under appropriate illumination so seeds containing the SPT insertion can be 

readily detected and separated from the progeny seeds that do not contain the 32138 SPT 

insertion in a highly efficient manner using mechanical color sorting (Figure 3, Color Sort A and 

B; Refer to Appendix 3). 

Step I: 32138 SPT Maintainer Seed Increase 

32138 SPT maintainer seed is replicated via self-pollination (Figure 3 Step I and Figure 4). The 

SPT insertion is transmitted maternally. Upon self-pollination, 32138 SPT maintainer produces 

two different types of seed (yellow: pinkish red) in a 1:1 ratio (Figures 5 and 11A). Yellow seed 

is non-transgenic for SPT (does not contain the 32138 SPT insertion). Pinkish red seed that 
83

fluoresces a bright red color under appropriate illumination is transgenic for SPT (contains the 

32138 SPT insertion). 

Color Sort A 

Self-pollinated 32138 SPT maintainer seed containing a mixture of yellow and pinkish red (SPT 

maintainer) seed in a 1:1 ratio is passed thru mechanical color sorters twice (Refer to Appendix 3 

for details) to separate the 32138 SPT maintainer seed from the yellow seed (Figure 3, Color Sort 

A and Figure 4). Color sorters detect the fluorescent red 32138 SPT maintainer seed and separate 

it from the yellow/non-transgenic for SPT seed. Pure seed of 32138 SPT maintainer is then 

available for the propagation of non-transgenic male-sterile female inbred parent seed (Figure 3, 

Step I). Therefore, color sort A is for the purification of 32138 SPT maintainer seed. Yellow seed 

collected from color sort A will be discarded (Refer to Appendix 3 for more details). 

Step II: Male-Sterile Female Inbred Parent Seed Increase 

For seed increase of male-sterile (ms45/ms45) female inbred parent, 32138 SPT maintainer will 

be planted in either a 2:2 or 4:4 or 4:2 planting pattern (male-sterile female: 32138 SPT 

maintainer rows). Fertile pollen (that does not contain the 32138 SPT insertion and carry the 

ms45 recessive allele) from the 32138 SPT maintainer plants will cross-pollinate and fertilize 

nearly isogenic male-sterile (ms45/ms45) female inbred parent plants (Figure 3, Step II and 

Figure 5). The inbred seed produced on the male-sterile female inbred plants will maintain their 

homozygous recessive (ms45/ms45) state and genetic purity. All male-sterile progeny seed 

harvested will be yellow in color and will not contain the 32138 SPT insertion (Figure 5 and 

Refer to Appendix 4 for more details). 

Color Sort B 

The SPT system is highly genetically efficient (Refer to Appendix 4 and 5) and virtually all of 

the fertile pollen from 32138 SPT maintainer should be non-transgenic for SPT and therefore all 

of the male-sterile inbred progeny seed made using the pollen from 32138 SPT maintainer 

should also be non-transgenic for SPT. The purpose of the color sort B is to ensure the purity of 

the male-sterile female inbred parent by removing any seeds of 32138 SPT maintainer. Each 

batch of male-sterile female inbred parent seed is passed twice through the color sorter (Figure 3, 

Color Sort B and Figure 5). This step helps to assure that no seed of the 32138 SPT maintainer 

will be planted in the F1 hybrid seed fields that produce seed sold to growers (Figure 3, Step III). 

Steps III. Commercial Maize Hybrid Seed Production 

Commercial maize hybrid seed production (Figure 3, Steps III) using the male-sterile progeny 

seed derived using SPT technology will take place normally. The purity of the male-sterile 

female inbred progeny derived from the SPT process is insured by passing the seed twice 

through the mechanical color sorters (Refer to Appendix 3 for details on the color sorter). 

Therefore, the F1 hybrid seed harvested and sold to growers for commercial grain production is 

non-transgenic for SPT and the resulting F1 hybrid plants are fully fertile. 

Steps IV. Commercial Maize Grain Production 
84

Commercial maize grain production using the F1seed generated using the male-sterile female 

inbred parent will take place normally. The F1 hybrid plants grown in the growers’ fields are 

non-transgenic for SPT and therefore, the grain harvested from growers’ fields is also nontransgenic for SPT (Figure 3, Step IV).