September 11, 2012 

Submitted Via Federal eRulemaking Portal

Docket No. APHIS-2012-0019 

Regulatory Analysis and Development

Plant Protection Division

Animal and Plant Health Inspection Service

United States Department of Agriculture

Station 3A-03.8 

4700 River Road Unit 118 

Riverdale, MD 20737-1238 

Re: Preliminary Plant Pest Risk Assessment and Draft Environmental Assessment for 

Determination of Nonregulated Status of DAS-68416-4 Soybean Genetically Engineered for 

Herbicide Tolerance

To whom it may concern: 

These comments are submitted by Dow AgroSciences LLC (DAS) in response to the July 13, 

2012 announcement (the Notice) by the United States Department of Agriculture’s (USDA’s) 

Animal and Plant Health Inspection Service (APHIS or the Agency) of APHIS’s preparation of a 

preliminary plant pest risk assessment and draft environmental assessment (EA) in connection 

with the proposed determination on the status of the DAS herbicide-tolerant soybean, designated 

as DAS-68416-4 soybean, as a regulated article under the Plant Protection Act (PPA) and 

implementing APHIS regulations at 7 C.F.R. Part 340. 

The relationship of the pending DAS-68416-4 soybean petition to the previously submitted 

petition for a determination of non-regulated status for DAS-40278-9 corn genetically 

engineered for herbicide tolerance should also be noted. In this context, the material submitted 

here relating to the herbicides 2,4-D and glyphosate has relevance to the DAS-40278-9 corn 

action . 

DAS appreciates the opportunity to provide these comments for the Agency’s consideration. 

Herbicide Tolerance: DAS’ new soybean product (DAS-68416-4 soybean) provides tolerance 

to the currently approved herbicide, 2,4-dichlorophenoxy acetic acid (2,4-D) allowing this 

herbicide to be used on DAS-68416-4 soybean1

 without damaging the crop. DAS-68416-4 

soybean also provides tolerance to the approved herbicide glufosinate. 2,4-D has been used in 

the United States since 1948 to control broadleaf weeds. It is one of the most popular herbicides 

 

1 Soybean expressing the 2,4-D herbicide tolerance trait from DAS-68416-4 will be sold as EnlistTM soybeans. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
in use throughout the world and the most well-known and widely-used phenoxy auxin herbicide. 

2,4-D is approved for use for weed control applications in soybean fields and with many other 

crops, on pastures and rangeland, and in both commercial and residential settings for weed 

control in parks, and on golf courses, lawns and other non-crop areas. Glufosinate was first 

approved for use in the United States in 2000. It is used to control broadleaf weeds in fields 

where many crops are grown including apples, berries, canola, corn, cotton, currants, grapes, 

grass grown for seed, potatoes, rice, soybeans, sugar beets, and tree nuts, as well as in non-crop 

areas. DAS previously informed APHIS of the intention to stack DAS-68416-4 soybean with a 

soybean that has been genetically engineered to be tolerant of glyphosate, thereby allowing 

growers the use of herbicide combinations or mixtures to control weeds. 

DAS has developed a new form of 2,4-D, referred to as 2,4-D choline, that has significantly less 

volatility than other 2,4-D products and a new product formulation designed to reduce the 

potential for spray drift. The combination of the ultra-low volatility of 2,4-D choline and the 

drift reduction properties of the new product formulation will reduce potential exposure to 

humans and the environment, as well as the potential for off-site movement and injury to 

neighboring crops that are sensitive to 2,4-D. Under current commercialization plans, 2,4-D 

choline will be sold as a premix2 with the herbicide glyphosate. This premix is currently 

intended to be the only 2,4-D formulation which Dow AgroSciences plans to market for use on 

DAS-68416-4 soybean. 

Draft EA and PPRA: The EA prepared by APHIS presents an extensive evaluation of the 

potential effects on the quality of the human environment resulting from a determination of nonregulated status of DAS-68416-4 soybean. The EA is consistent with the Council of 

Environmental Quality’s (CEQ) regulations implementing the National Environmental Policy 

Act (NEPA) (40 CFR Parts 1500-1508), and the USDA and APHIS NEPA implementing 

regulations and procedures (7 CFR 1b and 7 CFR Part 372). This evaluation is broad in scope 

(addressing a number of issues including soy production, a comprehensive list of environmental 

considerations, public health considerations, animal feed and socioeconomic issues and 

threatened and endangered species), detailed, and thorough (240 pages of text, over 400 citations 

and 5 supporting Appendices). 

The analysis in the EA shows that there are no potentially negative impacts (including 

cumulative effects) on the environment of the Preferred Alternative (full deregulation of DAS68416-4 soybean) compared with the No Action Alternative. A potential benefit regarding 

reduced grower costs to control glyphosate resistant weeds identified for the Preferred 

Alternative was documented by APHIS in the EA (Section 4.8.1.2). 

The draft Plant Pest Risk Assessment documents that DAS-68416-4 soybean exhibits none of the 

characteristics of a plant pest – it is no more a plant pest than any other soybean line being grown 

commercially in the United States today. In addition, all of the herbicides that are likely to be 

used in DAS-68416-4 soybean fields, including 2,4-D, glufosinate and glyphosate (when DAS68416-4 is stacked with a deregulated glyphosate tolerance trait), are in widespread use in U.S. 

and global agriculture and are routinely used for weed control in major commodity crops grown 

 

2 EnlistTM Duo Herbicide with Colex-DTM Technology.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
for food and feed including soybean, crops rotated with soybean, or both. As discussed below, 

herbicides are regulated on an ongoing basis by the U.S. Environmental Protection Agency 

(EPA). 

Regulatory Oversight/Status: As recognized by the Coordinated Framework for Regulation of 

Biotechnology, in effect since 1986, APHIS has sole authority and responsibility for the decision 

on whether or not to deregulate DAS-68416-4 soybean or any other herbicide-tolerant crop. 

Separately, the EPA has sole authority and responsibility under the Federal Insecticide, 

Fungicide, and Rodenticide Act (FIFRA) for the decision on whether or not to approve the use of 

2,4-D on DAS-68416-4 soybean and, under Section 408 of the Federal Food, Drug, and 

Cosmetic Act (FFDCA), to approve any food safety tolerances that may be necessary for 

residues of the herbicides in or on the crop and foods produced from the crops. 

In order to approve the use of an herbicide or any other pesticide, EPA must find that it will not 

pose “any unreasonable risk to man or the environment.” For soybean and other food uses, EPA 

must find that any pesticide residues will be “safe”, defined as “a reasonable certainty that no 

harm will result from aggregate exposure to the pesticide chemical residue, including all 

anticipated dietary exposures and all other exposures for which there is reliable information.” 

The primary means by which EPA addresses potential risk associated with pesticide use is the 

product label and it is a violation of federal law for any person to use a pesticide in a manner 

inconsistent with its labeling. In addition to being legally required to follow the directions for 

use that will appear on the label for the 2,4-D choline/glyphosate premix, all growers of DAS68416-4 soybean will be contractually obligated to follow all of the requirements in the DAS 

Technology Use Agreement and accompanying Product Use Guide. 

2,4-D Safety: In 2005, EPA concluded an extensive registration review of 2,4-D and concluded 

that, after stipulating minor label changes, 2,4-D met FIFRA’s no unreasonable adverse effects 

standard. Enlist Duo with Colex-D Technology containing the new 2,4-D choline, combined 

with DAS’ product stewardship program is designed to reduce the potential for off-target 

exposures to humans or the environment compared to other 2,4-D formulations currently on the 

market. Extensive comments on the favorable toxicological, eco-tox, and environmental profile 

for 2,4-D have been provided by recognized experts to the APHIS public docket for DAS-40278-

9 corn (APHIS-2010-0103-4529, 4532, 4898 and 4920) and are applicable to DAS-68416-4 

soybean. 

In 2009, Dow AgroSciences submitted its petition to APHIS (Number 09-349-01p) seeking a 

determination that DAS-68416-4 soybean is “unlikely to pose a plant pest risk and, therefore, 

should no longer be a regulated article.” Separately, Dow AgroSciences has submitted an 

application to EPA to obtain approval for the use of its new 2,4-D choline formulation on DAS68416-4 soybean. Following established EPA policy, it is expected that these applications will 

be approved only after APHIS makes a determination of non-regulated status for DAS-68416-4 

soybean. The decisions to be made by APHIS and EPA are independent, statutorily enumerated 

actions. Finally, Dow AgroSciences has successfully completed a consultation with the U.S. 

Food and Drug Administration (FDA) concerning the safety of DAS-68416-4 soybean. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Weed Resistance Management: DAS intends to cross-breed deregulated DAS-68416-4 

soybeans with previously deregulated soybeans engineered to tolerate glyphosate. This 

commercialized “stacked” soybean will allow farmers to implement a robust integrated weed 

management (IWM) program utilizing multiple herbicides with differing modes of action. The 

use of differing herbicidal modes of action has been recommended by experts as a weed 

management strategy to help manage existing resistant weed varieties, and slow the development 

of new resistance incidents. As correctly noted in the EA, breeding a 2,4-D and glufosinate 

tolerant soybean (DAS-68416-4) with a glyphosate-tolerant soybean will allow growers to 

maintain methods and equipment already used with glyphosate-tolerant soybean, with the added 

ability to proactively manage weed resistance by using herbicides with multiple mechanisms of 

action.

Resistance within weed populations can develop from repeated use of any single control practice. 

This can result with nonchemical as well as chemical control methods when additional control 

practices are not employed. The wide-spread adoption of glyphosate-tolerant crops, along with 

the corresponding reduction in the use of other herbicides with differing modes of action, has 

resulted in the development of glyphosate-resistant and hard-to-control weed populations. These 

weeds threaten the productivity and economical sustainability of farming operations and risk a 

return to increased tillage as a weed control method, with the resulting loss of the environmental 

benefits offered through conservation tillage. The proposed use of Enlist Duo herbicide (a 

premix of glyphosate and 2,4-D) with DAS-68416-4 soybean offers a tool with multiple modes 

of action further strengthened by the historically low tendency for development of resistance to 

2,4-D. The use of DAS-68416-4 soybean and Enlist Duo herbicide offers an effective tool to 

manage existing populations of glyphosate-resistant weeds and prevent the development of new 

resistant weed populations, while minimizing the potential for development of resistance to 2,4-

D. Greater awareness of the resistance issue by growers, researchers and regulators, combined 

with DAS’ comprehensive stewardship program that provides IWM guidance, will maximize 

these benefits. Furthermore, farmers will be able to retain current reduced till practices that 

maintain soil integrity and water quality, and reduced fuel costs associated with machinery use 

without compromising productivity. 

Farmers, academics, and other members of the agricultural community submitted comments to 

the DAS-68416-4 soybean public comment docket (APHIS-2012-0019) stressing the need for 

additional weed management technologies. These comments explain that DAS-68416-4 soybean 

and Enlist Duo will fit well with growers’ existing weed management programs, equipment and 

expectations (a small sample of the publicly-available comments related to the need for this 

technology are APHIS-2012-0019, 0149, 0246, 0314, 0277 and 0201) 

Coexistence: The processes currently in place to allow organic and non-GE soybean production 

to coexist with conventional soybean production growing GE soybeans would also apply to 

DAS-68416-4 soybean. 

Non-regulatory and regulatory processes are in place, allowing organic crops, crops which may 

be sensitive to pesticides used in neighboring fields, and non-crop ecosystems to coexist with 

conventional soybean production. While these same processes would apply with the production 

of DAS-68416-4 soybean, advances in both the herbicide technology and product stewardship 

programs accompanying DAS-68416-4 soybeans and Enlist Duo herbicide further support 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
successful coexistence. The Enlist Duo herbicide that will be used with DAS-68416-4 soybean 

features Colex-D Technology and contains the new 2,4-D choline. Field and laboratory results 

demonstrate ultra-low volatility with this new form of 2,4-D, and the drift reduction properties 

built into the formulation greatly reduce potential for drift. The significant reduction in both 

volatility and drift greatly reduces the potential for off-target movement. In addition, DAS will 

implement a product stewardship program that incorporates voluntary as well as legal and 

contractual obligations for the end user, along with education, training, and compliance 

monitoring programs. The combination of the technology and stewardship will allow 

conventional soybean producers growing DAS-68416-4 soybean to continue to coexist with 

nearby organic or other crops sensitive to 2,4-D and non-crop ecosystems.

DAS is committed to product stewardship for all of its products and has developed a multifaceted stewardship program for DAS-68416-4 soybean that addresses the management of the 

crop, the trait and the herbicides. The program involves training, signed grower agreements, onfarm monitoring and product use guides that will serve to maintain and foster coexistence of the 

diverse agronomic practices implemented by soybean farmers in the U.S. A key element of this 

program is that growers that choose to use 2,4-D are required to use DAS’ novel 2,4-D chemistry 

and formulation technology that significantly reduces herbicide spray drift and volatility. Use of 

this technology will serve to bolster the existing EPA mandated herbicide label requirements 

designed to mitigate risks associated with off-target impacts of 2,4-D on sensitive crops and noncrop plants/organisms. 

Providing these benefits to growers through safe and effective technologies is a primary goal of 

DAS in the development of all our products including DAS-68416-4 soybean. 

As set forth above and in the attached materials, the comprehensive review documented in the 

EA provides decision-makers and the public with a thorough evaluation of the potential 

environmental impacts associated with deregulating DAS-68416-4 soybeans. DAS agrees with 

APHIS’ findings in the EA that there will be no significant effects on the human environment as 

a result of granting non-regulated status to DAS-68416-4 soybean and urges APHIS to issue a 

Finding of No Significant Impact and fully deregulate DAS-68416-4 soybean.

• We find that APHIS’ EA and Plant Pest Risk Assessment relating to DAS-68416-4 

soybean comprise a comprehensive evaluation of the potential effects on the environment 

associated with the full deregulation of DAS-68416-4 soybean. Based on its analyses, 

APHIS can reasonably conclude that full deregulation of DAS-68416-4 soybean would 

have no significant impact on the human environment. 

• The EA provides a wide ranging and robust analysis of the potential environmental 

impacts of deregulating DAS-68416-4 soybean.

• DAS seeks this opportunity to provide input on a few specific areas where additional 

supporting information could add clarity. 

1. DAS-68416-4 soybean will not significantly affect non-GE, organic or 

specialty soybean production and will not require a change in soybean seed 

production practices for non-GE or GE seed.

2. In the EA, APHIS has appropriately identified EPA as having regulatory 

authority over the use of pesticides in the US and has considered EPA’s risk 

assessments of the potential environmental and health effects of 2,4-D, 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
glufosinate and glyphosate used on DAS-68416-4 soybeans. In addition, 

APHIS has addressed the potential cumulative effects of new uses of 2, 4-D 

and glufosinate in conjunction with current usage, and has fully considered the 

EPA risk assessment processes and decision-making standards under FIFRA 

and FFDCA.

3. Through EPA approved label restrictions coupled with DAS’ comprehensive 

Stewardship Program deregulation of DAS-68416-4 soybean and its 

subsequent treatment with approved herbicides will not result in significant 

impacts to other sensitive crops or vegetation adjacent to DAS-68416-4 

soybean. 

4. Attached documents provide additional specific input on the EA, PPRA, 2,4-

D (grower application, toxicology, manufacturing impurities, off-target 

impact), product stewardship and coexistence. 

Dow AgroSciences appreciates the opportunity to provide these comments and stands ready to 

provide any additional information that APHIS may require. 

Sincerely,

Laura A. Tagliani

Regulatory Leader

Regulatory Sciences & Government Affairs

Dow AgroSciences LLC

9330 Zionsville Road

Indianapolis, IN 46268 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Dow AgroSciences LLC 

Comments to Docket ID APHIS-2012-0019

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page i 

TABLE OF CONTENTS

SECTION 1: STEWARDSHIP OF HERBICIDE TOLERANT TRAIT TECHNOLOGY 

FOR DAS-68416-4 SOYBEAN AND ASSOCIATED HERBICIDE 

PRODUCTS........................................................................................................ 1

SECTION 2: ESTIMATE OF HERBICIDE VOLUME AND IMPACT ON 

ENVIRONMENTAL LOAD OF HERBICIDES WITH THE 

INTRODUCTION OF ENLIST SOYBEAN (DAS-68416-4) ................... 26

SECTION 3: 2,4-D OFF-TARGET EXPOSURE AND SENSITIVE CROPS .................. 40

SECTION 4: TRAIT STACKING IN COMMERCIAL SOYBEANS .............................. 49

SECTION 5: 2,4-D TOXICITY EVALUATION ................................................................. 58

SECTION 5: APPENDIX 1: EPA DENIAL OF NOVEMBER 6, 2008 NRDC PETITION TO 

CANCEL ALL 2,4-D REGISTRATIONS (APRIL 7, 2012) ............. 76

SECTION 5: APPENDIX 2: EPA ORDER DENYING NRDC’S PETITION TO REVOKE 

TOLERANCES, 77 FED. REG. 23135 (APRIL 18, 2012) .............. 87

SECTION 6: ANALYSIS OF 2,4-D TECHNICAL ACID FOR THE PRESENCE OF 

DIOXINS AND FURANS.............................................................................. 112

SECTION 7: ERRATA TO DRAFT PLANT PEST RISK ASSESSMENT AND 

ENVIRONMENTAL ASSESSMENT FOR DAS-68416-4 SOYBEAN .... 117

SECTION 7: APPENDIX 1: NEW APPLICATION WINDOW FOR 2,4-D CHOLINE ON DAS68416-4 SOYBEANS FALLS WITHIN THE TIMING AND RATES OF 

OTHER 2,4-D USES APPROVED BY EPA ................................. 119

SECTION 7: APPENDIX 2: NON-GE SOYBEAN .................................................................. 124

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page ii

APPENDIX 1: CURRENT REGULATORY STATUS OF CERTAIN HERBICIDES 

THAT MAY BE USED ON DAS-68416-4 SOYBEAN ............................... 126

APPENDIX 2: 2,4-D CHOLINE FORMULATIONS AND U.S.-EPA REGISTRATION 

STATUS .......................................................................................................... 127

APPENDIX 3: LACK OF TOXICOLOGICAL OR BIOLOGICAL SYNERGISTIC 

EFFECTS BETWEEN GLYPHOSATE AND 2,4-D .................................. 128

APPENDIX 4: REPORT OF ISOLATED AUXIN RESISTANT WATERHEMP IN A 

GRASS SEED PRODUCTION FIELD; WEED CONTROL SOLUTIONS 

WITH MULTIPLE MODES OF ACTION WILL HELP ......................... 130

APPENDIX 5: ANALYSIS OF THE IMPACT OF ENLIST ON HERBICIDE USE ...... 132

REFERENCES:...........................................................................................142

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 1 

SECTION 1: STEWARDSHIP OF HERBICIDE TOLERANT TRAIT 

TECHNOLOGY FOR DAS-68416-4 SOYBEAN AND ASSOCIATED 

HERBICIDE PRODUCTS

Relevant to DAS-68416-4 Draft EA Section 4.2.2, 4.4.2, 5.1, 5.11, 5.14 

Summary

Dow AgroSciences (DAS) has submitted a petition to the United States Department of 

Agriculture (USDA)’s Animal and Plant Health Inspection Service (APHIS) for the 

determination of non-regulated status for DAS-68416-4 soybean, which provides tolerance to the 

herbicides 2,4-dichlorophenoxy acetic acid (2,4-D) and glufosinate. 

This document provides information pertaining to Dow AgroSciences’ comprehensive 

stewardship program for DAS-68416-4 soybean and its associated new herbicide technology, 

2,4-D choline salt. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 2 

Stewardship of Herbicide Tolerant Trait Technology for DAS-68416-4 Soybean 

and Associated Herbicide Products

Table of Contents 

1. Introduction ______________________________________________________________________ 5 

2. Stewardship Program Components ___________________________________________________ 5 

2.1 Authorized Use of DAS-68416-4 Soybean and Associated Herbicide Products

Through a Technology Use Agreement ________________________________________ 5 

2.2 Herbicide Technology Advancements 6 

2.3 Comprehensive Product Use Information 7 

2.3.1 Product Use Guide 

2.3.2 EPA Approved Product Labels Mandating Requirements and Restrictions

2.3.3 DAS-68416-4 Soybean Seed Packaging Information

2.3.4 Weed Resistance Management

2.4 Education and Training for Distributors, Retailers, Growers and Applicators_______ 10

2.5 Compliance Monitoring ___________________________________________________ 11

3. Stakeholder Outreach and Input ____________________________________________________ 12

4. Industry Commitment and Involvement ______________________________________________ 12

5. Conclusion_______________________________________________________________________ 13

6. References ______________________________________________________________________ 14

Appendices 

Appendix 1. Summary of Comprehensive Stewardship Program for DAS-68416-4 

Soybean and Enlist Duo Herbicide _________________________________ 15

Appendix 2: Technology Use Agreement ________________________________________ 16

Appendix 3: Product Use Guide _______________________________________________ 20

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 3 

Stewardship of Herbicide Tolerant Trait Technology for DAS-68416-4 Soybean and 

Associated Herbicide Products

Relevant to DAS-68416-4 Draft EA Section 4.2.2, 4.4.2, 5.1, 5.11, 5.14, 

Readers Note: Throughout this document reference is made to Enlist DuoTM Herbicide, which is a 

proprietary blend of 2,4-D choline and glyphosate dimethylamine salts. Dow AgroSciences has submitted to 

EPA for approval a proposed label for its Enlist Duo Herbicide with Colex-D Technology, a pre-mix of the 

new 2,4-D choline salt and glyphosate dimethylamine. The first submission to EPA is for use on Enlist corn, 

DAS-40278-9, and once approved then Dow AgroSciences will submit a label amendment for the use of Enlist 

Duo on DAS-68416-4 soybean. Enlist Duo Herbicide cannot be offered for sale until the product receives 

registration by EPA. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 4 

1. Introduction 

Dow AgroSciences is committed to promoting the responsible use and stewardship of its 

products throughout the product life cycle. Consistent with its existing stewardship programs and 

practices, Dow AgroSciences will implement comprehensive stewardship measures as part of the 

product launch for DAS-68416-4 soybean and associated herbicide products. The stewardship 

program will focus on educating and training retailers, growers and applicators on the 

appropriate use of DAS-68416-4 soybean and authorized herbicide products developed for use 

with DAS-68416-4 soybean. This will be accomplished using a multi-faceted approach, 

involving a variety of tools and delivery methods and working with customers, stakeholders and 

industry organizations to promote responsible use. The stewardship program is designed to: 

• Provide comprehensive guidance and education on responsible use 

• Promote compatibility with other crops and cropping systems 

• Minimize the potential for off-target movement

• Promote Weed Resistance Management3

 

• Promote responsible use and worker safety 

• Support compliance with applicable regulatory requirements 

2. Stewardship Program Components

The comprehensive stewardship program, as summarized in Appendix 1, is based on Dow 

AgroSciences’ ongoing commitment to stewardship and input from retailers, growers, 

applicators, regulators, and stakeholders. Key components of the stewardship program include: 

• Authorized use of DAS-68416-4 soybean and associated herbicide products through a 

Technology Use Agreement (TUA); 

• Herbicide technology advancements;

• Comprehensive product use information, including mandatory use requirements and 

restrictions;

• Education and training for distributors, retailers, growers and applicators; and

• Compliance monitoring. 

2.1 Authorized Use of DAS-68416-4 Soybean and Associated Herbicide Products Through 

a Technology Use Agreement 

Dow AgroSciences will authorize growers of DAS-68416-4 soybean through a Technology Use 

Agreement (see Appendix 2 for TUA) that requires growers to use the soybean trait technology 

responsibly and prohibits the use of unauthorized herbicides. Dow AgroSciences currently 

requires growers to sign the TUA, which is a formal contractual agreement for responsible use of 

 

3 Stewardship information on insect resistance management will also be included, as applicable.

TM Enlist and Enlist Duo are trademarks of Dow AgroSciences LLC.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 5 

its seed trait technology. In the case of DAS-68416-4 soybean, this contractual agreement will be 

expanded to include DAS-68416-4 soybean and its associated herbicide products. 

The Technology Use Agreement is a legal and contractual obligation that will require all growers 

of Dow AgroSciences’ products containing the Enlist trait to:

• Use only EPA accepted and Dow AgroSciences’ authorized herbicide products as the 

only phenoxy carboxylic acid (e.g., 2,4-D) herbicides used for post-plant applications to 

DAS-68416-4 soybean; 

• Read and follow the Product Use Guide (PUG) requirements (see Appendix 3 for an 

example of a draft of the Soybean PUG that will include information on the DAS-68416-

4 soybean, use of authorized herbicide products, and weed resistance management 

practices);

• Read and follow FIFRA pesticide product label directions, which will include 

requirements to use in a manner protective of the environment;

• Read and follow seed packaging information; and

• Provide access to information about use of the technology and allow on-farm 

assessments.

Furthermore, the Technology Use Agreement provides Dow AgroSciences the right to revoke a 

grower’s access to DAS-68416-4 soybean seed if stewardship requirements are not met.

 

2. 2 Herbicide Technology Advancements

Dow AgroSciences has discovered and developed a novel (non-ester or non-amine) 

2,4-D choline4 salt herbicide product for use with DAS-68416-4 soybean. The exceptionally 

low volatility of 2,4-D choline salt has been demonstrated in both laboratory studies and field 

studies. For example, in a laboratory study, wheat plants treated with rates ten times higher than 

specified on the label of 2,4-D choline were placed in an enclosed chamber with grape and 

tomato plants, which are sensitive to 2,4-D [1]. After 24 hours of exposure in the chamber at 

104°F, neither sensitive crop showed any symptoms of injury, which is typically characterized 

by leaf cupping, strapping, epinasty and twisting of the petiole and main stem of the plant. The 

lack of any symptoms on the grape and tomato plants is a clear indication of the highly reduced 

volatility of 2,4-D choline. Field results are consistent with these laboratory findings [2]. Trials 

were conducted in 2010 and 2011 in Arkansas, Georgia, and Indiana to measure volatility 

differences between 2,4-D ester, amine and choline forms under field conditions. The 2,4-D 

choline was six times less volatile than the DMA salt, which is considered essentially nonvolatile, and twenty-four times less volatile than the ethylhexylester form [3]. 

Additionally, Dow AgroSciences has developed an innovative premix formulation, Enlist DuoTM

Herbicide, that combines 2,4-D choline with glyphosate for use with DAS-68416-4 soybean5. 

As compared to tank mixes of traditional 2,4-D products and commercial glyphosate, this premix 

 

4 The United States Environmental Protection Agency (EPA) has accepted DAS’s submission for a wide range of 

crop and non-crop herbicide uses for 2,4-D choline salt. Registration for 2,4-D choline salt’s use with DAS-68416-4 

soybean will be submitted to EPA for review. 

5 Applications for 2,4-D choline and associated herbicides for use with DAS 68416-4 soybean will be submitted to 

EPA. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 6 

uses formulation technologies that will result in a significant reduction in herbicide off-target 

movement from particle drift [4]. Field research has validated the observations from laboratory 

and wind tunnel studies. The drift reduction technology built into Enlist Duo Herbicide reduced 

drift >50% compared to a standard tank mix using conventional flat fan nozzles as well as 

advanced drift reduction nozzles. Compared to a conventional 2,4-D/glyphosate tank mix and 

flat fan nozzles, drift was reduced 90% when Enlist Duo Herbicide was combined with drift 

reduction nozzles [5]. The Product Use Guide will include recommendations on equipment (e.g. 

nozzles to minimize driftable spray droplets), calibration, use and maintenance. 

A variety of factors including weather conditions (e.g., wind direction, wind speed, temperature, 

and relative humidity) and method of application can influence pesticide drift. The product label 

to be accepted by EPA will require users to evaluate these factors and make appropriate 

adjustments when applying Enlist Duo Herbicide for use with DAS-68416-4 soybean. The 

Product Use Guide will include information on environmental conditions such as wind speed and 

field temperature that will assist the herbicide applicator to minimize the potential for off-target 

movement due to particle or vapor drift. 

2.3 Comprehensive Product Use Information 

2.3.1 Product Use Guide

Dow AgroSciences will provide DAS-68416-4 soybean growers a comprehensive Product Use 

Guide that is a material part of the Technology Use Agreement and details the requirements for 

responsible use. As a standard practice, Dow AgroSciences provides a Product Use Guide to 

users (e.g., retailers, dealers, growers, applicators) of its technology. The Product Use Guide 

provides growers comprehensive information including required and recommended management 

practices. The Product Use Guide for DAS-68416-4 soybean will include detailed requirements 

for responsible use of the soybean and associated herbicide products. It will include information 

on weed resistance management, application and management of off-target herbicide movement, 

as well as seed planting directions and grain stewardship. 

The Product Use Guide will require DAS-68416-4 soybean growers to: 

• Use only EPA accepted and Dow AgroSciences’ authorized herbicide products as the 

only phenoxy carboxylic acid with Enlist soybeans 

• Read and follow FIFRA pesticide product label directions 

• Use properly maintained and calibrated ground application equipment for herbicide 

applications with minimum boom heights

• Use nozzles that produce a droplet size that meets the criteria specified on the authorized 

herbicide label and reduce the potential for physical drift 

• Follow instructions for equipment clean-out after product use 

• Follow Weed Resistance Management guidelines, recommending utilization of herbicide 

products with additional modes of action 

• Read and follow grain marketing guidelines 

• Provide management practices to promote compatibility with other crops 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 7 

The Product Use Guide will promote appropriate cultural practices including diversified weed 

control strategies (e.g. herbicide use or crop rotation) to minimize selection for herbicideresistant weed populations. Responsible use of the soybean seed and herbicides in an integrated 

farming system promotes compatibility with other crops.

2.3.2 EPA Approved Product Labels Mandating Use Requirements and Restrictions

Dow AgroSciences has submitted to EPA for approval a proposed label for its Enlist Duo 

Herbicide with Colex-D Technology, a pre-mix of the new 2,4-D choline salt and glyphosate 

dimethylamine. The first submission to EPA was for use on Enlist corn, DAS-40278-9, and once 

approved, Dow AgroSciences will submit a label amendment for the use of Enlist Duo on DAS68416-4 soybean. That label language will include detailed use directions and application 

requirements designed to minimize the potential for weed resistance development, minimize the 

potential for off-target movement, and promote worker safety. 

The proposed Enlist Duo herbicide product label (2,4-D choline and glyphosate premix), to be 

submitted for EPA acceptance, will contain comprehensive information and requirements for 

responsible use for control of broadleaf weeds in DAS-68416-4 soybean. Pending EPA review 

and acceptance, these labels will specify use directions and requirements for spray drift and 

volatilization management designed to minimize the potential for misapplication or off-target 

movement of 2,4-D choline-containing herbicide products to agricultural and non-agricultural 

land. 

The Enlist Duo herbicide label will require herbicide applicators to: 

• Follow all state and local regulations for application of herbicides containing 2,4-D 

• Apply via ground application only 

• Use properly maintained and calibrated ground application equipment with minimum 

boom heights 

• Use drift reduction nozzles that produce a coarse or coarser droplet size 

• Use an upwind setback from sensitive areas 

• Adhere to wind speed restrictions on ground applications 

• Avoid applications into areas of temperature inversion 

• Follow instructions for equipment clean-out after product use 

Dow AgroSciences will provide worker safety information in accordance with EPA requirements 

through herbicide product labeling, Product Use Guides, training and educational materials. 

Pending EPA review and acceptance, the Enlist Duo herbicide label will specify the following 

typical Agricultural Use Requirements in accordance with the Worker Protection Standard: 

• Do not enter or allow worker entry into treated areas during a restricted entry interval 

(REI) of 48 hours. 

• Personal Protective Equipment (PPE) is required for early entry to treated areas 

permitted under the Worker Protection Standard and that involves contact with anything 

that has been treated, such as plants, soil, or water includes coveralls, chemical-resistant 

gloves made of any waterproof material, shoes plus socks and protective eyewear. 

In addition, the following information will also be included on the Enlist Duo herbicide label: 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 8 

• Personal protective equipment for mixers, loaders, applicators, flaggers and handlers 

• Engineering controls 

• User safety recommendations

• First aid and emergency assistance

• Appropriate storage and disposal of pesticide and containers 

In summary, Dow AgroSciences has submitted to EPA for approval a proposed label for its 

Enlist Duo Herbicide with Colex-D Technology for use on Enlist corn, DAS-40278-9, and once 

approved, Dow AgroSciences will submit a label amendment for the use of Enlist Duo on DAS68416-4 soybean. The Enlist Duo herbicide product label will include comprehensive 

information and requirements for responsible use of Enlist Duo Herbicide with DAS-68416-4 

soybean. Such label directions are designed to minimize the potential for weed resistance 

development, minimize the potential for off-target movement, and promote worker safety. In 

addition, the submitted label does not allow herbicide application through any type of irrigation 

equipment and prohibits aerial application. 

2.3.3 DAS-68416-4 Soybean Seed Packaging Information 

Packages of DAS-68416-4 soybean seed will have product stewardship information on the seed 

bags and seed tags, including use requirements and a customer information telephone number. 

Information will be included on seed packaging to communicate the presence of herbicide 

tolerant traits. This information will also be included in the Product Use Guide, training, and 

marketing materials. 

2.3.4 Weed Resistance Management

Use of DAS-68416-4 soybean with associated herbicides will enable growers to control weeds 

that are hard-to-control or resistant to glyphosate6

. DAS-68416-4 soybean will provide an 

important alternative to glyphosate-only herbicide tolerant soybean by enabling the use of 2,4-D 

choline and glufosinate on this soybean for weed control. 

Based on the mode-of-action classification system of the Weed Science Society of America, 2,4-

D is a Group 4 growth regulator herbicide (synthetic auxin). Some naturally occurring weed 

biotypes that are tolerant (resistant) to 2,4-D may exist due to genetic variability in a weed 

population. Where resistant biotypes exist, the repeated use of herbicides with the same mode of 

action can lead to the selection for resistant weeds. Certain agronomic practices reduce the 

 

6

The following definitions are applied throughout this document: 1). Herbicide Tolerant Crop: A crop plant that 

has been developed (using techniques such as genetic engineering or selection of variants produced by tissue 

culture or mutagenesis) to survive and reproduce after treatment with a specific herbicide or herbicides that would 

normally damage an unmodified crop; 2). Herbicide Resistant Weed: A herbicide-resistant weed is a member of a 

population within a species that has an inherited ability to survive and reproduce following exposure to a dose of a 

herbicide normally lethal to susceptible populations of the species. Through repeated herbicide selection, the 

resistant population becomes dominant in a given area, and 3). Hard-to-Control Weed: A weed species that is 

inherently able to withstand treatment with a herbicide as a result of natural factors not involving herbicide 

selection or genetic mutation. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 9 

likelihood that resistant weed populations will develop and can be utilized to manage weed 

resistance once it occurs. 

Proactively implementing diversified weed control strategies to minimize selection for weed 

populations resistant to one herbicide or more is recommended by the Weed Science Society of 

North America [6]. A diversified weed management program may include the use of multiple 

herbicides with different modes of action and overlapping weed spectrum with or without tillage 

operations and/or other cultural practices. Research has demonstrated that using the labeled rate 

and directions for use is important to delay selection for resistance. 

To aid in the prevention of developing 2,4-D resistant weeds, Dow AgroSciences recommends 

the following practices for herbicide selection, crop selection and cultural practices, which are 

consistent with the recommendations of the Weed Science Society of America:

Herbicide Selection 

• Rotate the use of Enlist DuoTM Herbicide with non-auxin (non-Group 4) and non-glycine 

(Group 9) herbicides 

• Utilize a broad spectrum soil-applied herbicide as a foundation treatment 

• Utilize herbicides with alternative modes of action 

• Avoid using more than two applications of a Group 4 herbicide within a single growing 

season unless mixed with another mode of action herbicide with overlapping spectrum 

• Apply labeled rates of Enlist Duo Herbicide at the specified time (correct weed size) to 

minimize escapes of tolerant weeds

Crop Selection and Cultural Practices 

• Incorporate additional weed control practices whenever possible, such as delayed 

planting, crop rotation, mechanical cultivation and weed-free crop seeds, as part of an 

integrated weed control program 

• Do not allow weed escapes to produce seeds, roots or tubers 

• Thoroughly clean plant residues from equipment before leaving fields suspected to 

contain resistant weeds

• Scout fields after application to detect weed escapes or shifts in weed species 

• If resistance is suspected, treat weed escapes with an alternate mode of action or 

cultivation 

• Report any incidence of repeated non-performance of this product against a particular 

weed species to local retailer or Dow AgroSciences representative

Such weed resistance management practices will be recommended in the Product Use Guide for 

Dow AgroSciences’ DAS-68416-4 soybean and Enlist Duo Herbicide to help preserve product 

efficacy and promote weed resistance management. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 10 

2.4 Education and Training for Distributors, Retailers, Growers and Applicators

Dow AgroSciences will provide comprehensive education and training in multiple formats to 

distributors, retailers, growers, and applicators to reinforce the requirements for proper 

stewardship and responsible use. Dow AgroSciences provides comprehensive training on its 

portfolio of products through a variety of formats. Education and training, reinforced through 

product profiles, technical bulletins, sales literature, direct mailing and websites will also be 

presented in multiple formats to enhance learning and mastery of core concepts related to the 

EnlistTM stewardship program. 

A variety of educational formats will be used to promote concept learning. Training will be 

provided through face-to-face meetings, retailer visits, field visits, and self-paced learning 

modules on: 

• Stewardship requirements for responsible use of DAS-68416-4 soybean and associated 

herbicides, 

• Spray technology, 

• Spray quality basics,

• Herbicide application, and

• Weed resistance management.

This training will reinforce the soybean grower’s obligation to adhere to product use guidelines, 

FIFRA Pesticide Product Labels, seed product information and all product stewardship 

requirements for responsible use and proper stewardship. Training is an ongoing process, with 

interactive learning incorporated, where applicable, to promote responsible use and stewardship. 

Multiple resources and tools will be available to the growers and applicators to promote and 

communicate the importance of stewardship and responsible technology use. In addition to the 

Technology Use Agreement, Product Use Guide, and training, additional resources will be 

available, including: 

• Customer Service 

• Technical Bulletins

• AdvanceFarming.com 

• On-line training library

• In-field experts

• Trait stewardship website (www.traitstewardship.com)

• Stewardship tools (e.g. nozzle selector, sensitive crop registries) 

An extensive network of Dow AgroSciences sales representatives, field scientists, and 

agronomists will play an important role in educating and training retailers, growers and 

applicators on the proper use of the soybean seed, the herbicides and herbicide application 

guidelines. Dow AgroSciences’ field personnel, in addition to product suppliers, will work with 

growers to select the seed and herbicide products appropriate to their needs, growing conditions, 

and proper application equipment for field conditions. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 11 

2.5 Compliance Monitoring 

Dow AgroSciences will monitor compliance with the Technology Use Agreement and Product 

Use Guide through surveys and on-farm assessments. Upon request by Dow AgroSciences, 

DAS-68416-4 soybean growers must provide information regarding the location of fields planted 

with DAS-68416-4 soybean, and the herbicides applied to these fields. 

Failure to follow the stewardship requirements will result in:

• Education and reinforcement of the stewardship requirements with growers, applicators 

and retailers, 

• Additional education and training, and/or 

• Loss of access to DAS-68416-4 soybean.

3. Stakeholder Outreach and Input

Dow AgroSciences is using a variety of methods to obtain stakeholder input in the development 

of this stewardship program. Dow AgroSciences is consulting with retailers, growers and 

applicators to understand and address their needs in order to develop an effective and 

comprehensive stewardship program. In addition, Dow AgroSciences is proactively seeking 

input from recognized experts with a diverse range of experience in U.S. agriculture, as well as 

producers and processors of non-target crops. These efforts will support implementation of 

stewardship practices as broadly as possible throughout the value chain. 

Dow AgroSciences will evaluate additional feedback from retailers, growers and applicators for 

the continuous improvement of this stewardship program following the launch of DAS-68416-4 

soybean. 

4. Industry Commitment and Involvement 

Dow AgroSciences participates in several organizations and associations globally to promote the 

safe research and development, production, distribution, and responsible use of agricultural 

chemical and biotechnology products. 

Dow AgroSciences is a participant in the Herbicide Resistance Action Committee (HRAC) 

[hracglobal.com], an industry-based group supported by CropLife International 

[croplife.org/public/resistance_management]. HRAC focuses on encouraging responsible 

herbicide usage, communicating herbicide resistance management strategies and supporting their 

implementation through practical guidelines. HRAC engages in active collaboration with public 

and private researchers, especially in the areas of problem identification and devising and 

implementing herbicide management strategies. 

Dow AgroSciences’ personnel interact with academic weed scientists in addressing weed 

resistance management [wssa.net/Weeds/Resistance] issues. Dow AgroSciences conducts joint 

trials at university sites as well as seeks input from university researchers regarding weed 

management. Dow AgroSciences also participates in a wide range of professional organizations 

including agronomy societies, seed trade groups, weed science societies, and crop commodity 

groups. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 12 

In addition to managing the technology in accordance with the applicable requirements of federal 

and state government agencies, Dow AgroSciences is a Founding Member of the biotechnology 

industry’s Excellence Through Stewardship organization, which encourages effective and 

comprehensive stewardship programs and quality management systems throughout a genetically 

engineered crop’s development and commercialization. 

5. Conclusion 

Dow AgroSciences is committed to promoting the responsible use and stewardship of DAS68416-4 soybean and associated herbicide products. The comprehensive stewardship program 

outlined here incorporates elements to: 

• Promote responsible use of DAS-68416-4 soybean and associated herbicide products, 

• Promote compatibility with other crops, 

• Minimize the potential for off-target movement of herbicide, 

• Promote Weed Resistance Management, and

• Support compliance with all relevant state and federal requirements.

The stewardship program, focusing on education and management practices for proper use of the 

soybean and herbicides, coupled with the physical attributes of Enlist DuoTM (e.g., ultra-low 

volatility, minimized potential for drift, decreased odor and improved handling characteristics) 

enables coexistence with organic crops, crops traditionally sensitive to 2,4-D, and nongenetically engineered soybean.

Education and training efforts are also an integral part of the stewardship effort, promoting 

awareness and understanding of proper use of the soybean and herbicides. The combination of 

EPA mandated herbicide label requirements, Dow AgroSciences’ stewardship program, and 

associated proprietary herbicide technology will provide the grower of DAS-68416-4 soybean 

with the tools needed to mitigate potential risk to the human health and the environment without 

compromising farm productivity. 

 

 Excellence Through Stewardship is a registered trademark of Excellence Through Stewardship.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 13 

SECTION 1: APPENDIX 1. Summary of Comprehensive Stewardship Program for DAS68416-4 Soybean and Enlist Duo

Proposed Enlist DuoTM Herbicide FIFRA Pesticide Product Label:

 Will require applicators to follow all state and local pesticide drift requirements regarding herbicide applications.

 Will not allow aerial or chemigation applications (i.e. ground application only).

 Will restrict ground applications at wind speeds less than or equal to 15 mph.

 Will require an applicator to assess whether a temperature inversion exists. Applications into areas of temperature 

inversion will not be allowed. 

 Will require using spray nozzles in accordance with manufacturer recommendations that produce a droplet size 

classification of coarse or coarser (ASABE S-572 standard).

 Will require an upwind setback from sensitive areas based upon the combination of droplet size, wind speed and boom 

height.

 Will require applicators to use extreme care when applying this product to prevent injury to desirable plants and crops. 

 Will require use of properly maintained and calibrated ground application equipment with minimum boom heights 

based upon nozzle manufacturer’s recommendations. 

 Will provide detailed instructions for sprayer and equipment clean-out after product use.

DAS-68416-4 Soybean Access via Signed Technology Use Agreement:

 Will require growers to utilize Dow AgroSciences’ Authorized Herbicide as the only phenoxy carboxylic acid products 

with DAS-68416-4 soybean.

 Will require growers to read and follow the Product Use Guide.

 Will require growers to read and follow FIFRA pesticide product labels.

 Will require growers to read and follow seed packaging information.

 Will require growers to provide Dow AgroSciences with access to information about soybean plantings and herbicide 

use and allow on-farm assessments.

 Will provide Dow AgroSciences right to revoke DAS-68416-4 soybean access if stewardship requirements are not met.

Product Use Guide:

 Will require growers to read and follow FIFRA pesticide product labels.

 Will require growers to utilize Dow AgroSciences’ Authorized Herbicides as the only phenoxy carboxylic acid products 

with Enlist soybeans.

 Will require the use of nozzles that meet the criteria specified on the label that reduce the potential for physical drift.

 Will require growers to use properly maintained and calibrated ground application equipment for herbicide 

applications with minimum boom heights.

 Will require technology users to follow instructions for equipment clean-out after product use.

 Will require growers to follow Weed Resistance Management guidelines, recommending utilization of herbicide 

products with additional modes of action.

 Will require growers to read and follow grain marketing guidelines.

 Will require growers to maintain records of planting locations of DAS-68416-4 soybean.

 Will provide management practices to promote compatibility with other crops.

Education and Training for Distributors, Retailers, Growers and Applicators:

 Will reinforce grower requirements to adhere to the Product Use Guide, FIFRA pesticide product labels, seed bag and 

tag information, and stewardship requirements for responsible use. 

 Will provide product guidance to retailers on responsible use to promote proper stewardship.

 Will include responsible use of trait and herbicide technology, weed resistance management, spray technology and 

stewardship requirements.

 Will include use of a variety of tools and delivery methods to reach distributors, retailers, growers and applicators.

TMEnlist and Enlist Duo are trademarks of Dow AgroSciences LLC. Some components have not yet received regulatory 

approvals; approvals are pending. The information provided here is not an offer for sale.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 14 

SECTION 1: APPENDIX 2. Technology Use Agreement 

Following is an example of the current Technology Use Agreement that requires growers to use 

the technology responsibly and prohibits the use of unauthorized herbicides. The Technology 

Use Agreement is a legal and contractual obligation that details requirements for the technology 

users.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 15 

1. DEFINITIONS: Each of the following terms shall have the meaning specified below:

• “Agreement” means, as of any date of determination, this Technology Use Agreement, and the then current (i) Product Use Guide(s) 

and (ii) Annual Technology Notification(s) for Purchased Seed, all of which are incorporated herein and deemed a material part of 

this Agreement.

• “DAS” and “Dow AgroSciences” mean Dow AgroSciences LLC and its affiliated companies, the principle address of which is 

9330 Zionsville Road, Indianapolis, IN 46268.

• “DAS Authorized Herbicide Product(s)” means agricultural products that contain either phenoxy carboxylic acid or AOPP

herbicides or both that are expressly labeled for use with EnlistTM crops and are specified in a Product Use Guide. Examples include 

products that contain 2,4-D or quizalofop where the products are specifically labeled for use on EnlistTM crops.

• “DAS Sourced Technology(ies)” means proprietary germplasm and all current and future seed trait technologies relating to 

Purchased Seed as set forth in applicable PUG(s) and Annual Technology Notification(s). At the time of the execution of this 

Agreement, DAS Sourced Technologies covered as Licensed Rights by this Agreement include, but are not limited to those listed in 

numbered paragraph 10 of this Agreement.

• “Grower” means the individual farmer or farming entity identified in the Grower Information Box.

• “Annual Technology Notification” means a yearly communication to Growers with updated information regarding new and 

existing DAS Sourced Technologies, including (among other things) the U.S. patents licensed under this Agreement and any new or 

modified terms. The Annual Technology Notification(s) for Purchased Seed shall become a part of this Agreement, and Grower’s 

use of DAS Sourced Technologies following receipt of any Annual Technology Notification for Purchased Seed constitutes Grower’s 

acceptance of all terms in the Annual Technology Notification.

• “Licensed Rights” mean all patent claims, trade secrets, rights existing under the US Plant Variety Protection Act (or its foreign 

equivalents), and other intellectual property rights relating to DAS Sourced Technology(ies) that are reasonably necessary for a 

Grower’s exercise of the limited license granted under numbered paragraph 2 herein with respect to Purchased Seed. The Licensed 

Rights will be set forth in applicable PUG(s) and Annual Technology Notification(s)

• “Product Use Guide” and “PUG” mean the document(s) published and updated by DAS from time to time, which specify, 

among other things, stewardship management practices for Seed and DAS Authorized Herbicide Product(s). The PUG(s) for 

Purchased Seed shall become a part of this Agreement, and Grower’s use of DAS Sourced Technologies following receipt of any 

PUG constitutes Grower’s acceptance of all terms in the PUG.

“Purchased Seed” means Seed that is purchased by a Grower from a Seed Seller under a fully executed Technology Use Agreement 

to which Grower and DAS are parties. 

• “Seed” means agricultural planting seed containing DAS Sourced Technologies sold by DAS Seed Sellers.

• “Seed Seller” means those entities authorized by DAS to sell Seed.

• “Third-Party Trait Technology” means proprietary trait technology from a technology provider other than DAS.

2. LIMITED LICENSE: Upon acceptance by DAS (or its authorized representative) of this Agreement, unaltered and duly executed 

by Grower, Grower is granted and hereby accepts, on and subject to the terms and conditions of this Agreement, a limited, nontransferable, revocable, non-exclusive license by DAS under the Licensed Rights to purchase Seed from Seed Seller and to plant 

Purchased Seed to produce a single commercial crop in the United States. In addition, when Grower purchases Seed and plants 

Purchased Seed containing Enlist Technology, Grower shall receive a limited license to apply DAS Authorized Herbicide Products 

in Enlist crops grown from such Purchased Seed. This limited license only covers Grower’s activities in the United States and does 

not authorize Grower to plant Seed in the United States that has been purchased/acquired in another country or to plant Seed in 

another country that has been purchased/acquired in the United States. Grower acknowledges and agrees that Grower is NOT 

permitted: (1) to supply, transfer, license or sublicense any Seed or DAS Sourced Technology to any other person, entity or other 

third party for planting or any other purposes; (2) to save or use any seed produced from Seed for planting by Grower or any 

other third party; or (3) to use or allow others to use Seed or any plant material produced from Seed for crop breeding, seed

production, research (including, without limitation, agronomic testing or generation of comparative data against seed 

containing Third-Party Trait Technology), or generation of regulatory approval data.

3. UPDATES ARE PART OF THIS AGREEMENT: Grower acknowledges and agrees the PUG, as updated and published from 

time to time by DAS, is incorporated herein and deemed a material part of this Agreement. For so long as Grower has a valid 

Agreement in effect with DAS, DAS will use reasonable efforts to provide Grower with the current PUG. Notwithstanding the 

foregoing, Grower agrees that it is Grower’s responsibility to obtain and comply with the current PUG. The current PUG is available 

from authorized sellers of the Seed, from DAS directly and/or on one or more DAS websites. Grower’s use of Seed after DAS 

publishes a new PUG or updates a PUG constitutes Grower’s acceptance of and agreement to be bound by the provisions of 

such new or revised PUG. Grower agrees to follow all Insect Resistance Management (IRM) requirements set forth in the PUG, 

including any to establish and maintain a refuge. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 16 

Grower also acknowledges and agrees that the Annual Technology Notification is incorporated herein and deemed a material part

of this Agreement. For so long as Grower has a valid Agreement in effect with DAS, DAS will send an Annual Technology 

Notification to Grower at the address identified by Grower above. Grower’s use of Seed after DAS publishes a new Annual 

Technology Notification constitutes Grower’s acceptance of and agreement to be bound by the provisions of such new 

Notification.

4. STEWARDSHIP AND COMPLIANCE: 

• Grower agrees to read and follow all applicable PUGs and product labels associated with DAS Sourced Technologies and DAS 

Authorized Herbicide Products. 

• DAS Authorized Herbicide Products are the only phenoxy carboxylic acid and AOPP herbicides authorized for use with Enlist 

crops during any pre-plant interval and after planting. When using a herbicide containing phenoxy carboxylic acid and/ or AOPP 

herbicide with Enlist crops during any pre-plant interval or after planting, Grower agrees to only use DAS Authorized Herbicide 

Products. 

• Grower agrees to provide Grower’s reasonable cooperation to DAS and its representatives and the representatives of any owner 

of DAS Sourced Technology (the “Representatives”) in connection with their efforts to verify Grower’s compliance with 

stewardship, IRM and other requirements hereof, including, but not limited to, completing written and oral questionnaires. Grower 

authorizes the Representatives to enter upon land where Grower has planted or is growing Purchased Seed as well as any refuge 

area for purposes of examining the land and Grower’s crop and taking samples thereof. Grower authorizes the Representatives to 

review the USDA Farm Service Agency crop reporting information, including Form 578 and corresponding aerial photographs. 

Upon the request of the Representatives, Grower shall furnish copies of invoices for Grower’s purchase of the DAS Sourced 

Technology(ies) and DAS Authorized Herbicide(s), and Grower will disclose to the Representatives certain information to confirm 

compliance with this Agreement, including the locations of all fields planted with crops containing DAS Sourced Technology(ies),

the identities of all herbicides applied to these fields, and other data as specified in the PUG(s).

5. TERM AND TERMINATION: This Agreement, once signed by Grower and accepted by DAS, will remain in effect until 

terminated or superseded. Grower or DAS may terminate this Agreement at any time for any reason by sending notice of 

termination to the other party at the address specified above. In addition to the foregoing, DAS reserves the right to revoke

Grower’s right to use one or more particular DAS Sourced Technology(ies) upon notice to the Grower. In the case of termination by 

Grower, such notice of termination must include Grower’s full name and address. Upon termination of this Agreement for any 

reason, Grower will no longer have a right to purchase or use Seed; however, Grower’s obligations and DAS’ rights that arose 

under the Agreement prior to termination will continue in effect. 

6. TRAIT FEES: Grower agrees to timely pay DAS or its designated representative all applicable fees that are a part of, associated 

with or collected with the purchase and use of any Seed and/or DAS Sourced Technology upon DAS’ payment terms then in effect. 

DAS reserves the right to change from time to time the amount of and how it charges technology fees. Grower shall pay interest to 

DAS on any past-due technology fees at the rate of 1.5% per month (18% per annum) or the maximum amount permitted by law, 

whichever is less, from the applicable due date for such fees until paid. Any payments received by DAS may be applied to unpaid 

fees, interest or other charges in DAS’ discretion.

7. LIMITATIONS OF WARRANTIES AND REMEDIES: DAS warrants that the DAS Sourced Technologies licensed hereunder 

conform to the written description in the current PUG and the Seed bag or Seed tag affixed to the unit of seed containing DAS 

Sourced Technology. This warranty applies only to the DAS Sourced Technologies contained in Seed that has been purchased from

a Seed Seller.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY 

WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE WHICH ARE HEREBY 

DISCLAIMED. 

Because DAS must have sufficient time to investigate any claim regarding the performance or non-performance of Seed and/or 

DAS Sourced Technology, no claim can be asserted against DAS unless Grower gives notice to DAS within fifteen (15) days 

after Grower first observes indications that the performance of the Seed and/or DAS Sourced Technology is not as warranted. 

GROWER’S EXCLUSIVE REMEDY FOR ANY CLAIM OR LOSS, INCLUDING, WITHOUT LIMITATION, CLAIMS 

ALLEGING STRICT LIABILITY OR NEGLIGENCE, SHALL BE LIMITED TO REPAYMENT OF THE AMOUNT OF THE 

PURCHASE PRICE FOR THE AFFECTED SEED. IN NO EVENT SHALL DAS, ITS AFFILIATES, DEALERS OR LICENSEES BE 

LIABLE FOR ANY INCIDENTAL, SPECIAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE 

SEED.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 17 

8. THIRD-PARTY TRAIT PROVIDERS: 

• Grower acknowledges and agrees this Agreement is entered into for the benefit of Third-Party Trait Technology providers to 

the extent their trait technologies are licensed as DAS Sourced Technologies hereunder and, as third-party beneficiaries, these 

Third-Party Trait Technology providers are entitled to enforce the provisions of this Agreement, as they may pertain to their 

respective trait technologies, against Grower, including maintaining a legal action directly against Grower.

• In the case of some Third-Party Trait Technology contained in the Seed and identified in the PUG, Grower may be required to 

obtain a limited license to use such technology directly from the owner of such Third Party Trait Technology.

9. ADDITIONAL PROVISIONS:

• Grower agrees to communicate all applicable terms, conditions and restrictions on Seed whether under this Agreement, a PUG, an 

Annual Technology Notification or otherwise to all persons and entities possessing or taking an interest in Grower’s Seed and grain 

therefrom. 

• Grower agrees that should any information provided to DAS herein change, Grower will promptly provide DAS with Grower’s 

updated information at the DAS address provided above.

• Grower’s rights under this Agreement may not be transferred or assigned to any other person, entity or third party without the 

written consent of DAS. 

• This Agreement (including PUGs and Annual Technology Notifications) constitutes the entire agreement between Grower and 

DAS regarding the subject matter hereof and all prior agreements between Grower and DAS with respect to the subject matter 

hereof are superseded.

• If any provision in this Agreement is determined to be void or unenforceable, the remaining provisions shall remain in full force 

and effect.

• The failure of DAS or any Third-Party Technology providers to exercise one or more of its rights under this Agreement on one or 

more occasions shall not be deemed a waiver to exercise such right(s) on one or more subsequent occasions.

• Governing Law: This interpretation and enforcement of this Agreement shall be governed by the laws of the State of Indiana 

without regard to its choice of laws provisions.

• Enforcement Costs: Grower agrees that DAS and any owners of the patents covered by this Agreement shall be entitled to recover 

any costs or expenses, including, but not limited to, court costs or reasonable attorneys fees, it incurs in enforcing its rights under 

this Agreement.

10. CURRENT DAS SOURCED TECHNOLOGIES INCLUDE: 

• Herculex® I Insect Protection

• Herculex® RW Rootworm Protection

• Herculex® XTRA Insect Protection

• WideStrike® Insect Protection cotton

• SmartStax® corn 

• Refuge Advanced® powered by SmartStax®

• EnlistTM Weed Control System 

• Agrisure® CB/LL corn

• Agrisure® GT corn

• Agrisure VipteraTM corn

SmartStax multi-event technology developed by Dow AgroSciences and Monsanto. Herculex Insect Protection 

technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex, WideStrike, Refuge Advanced and Enlist are 

trademarks of Dow AgroSciences LLC. SmartStax is a trademark of Monsanto Technology LLC. Agrisure and 

Agrisure Viptera are trademarks of a Syngenta Group Company. Always follow grain marketing and IRM 

requirements and pesticide label directions. Bt and Enlist products may not be registered in all states. Check with 

your seed representative for the registration status in your state. ©2012 Dow AgroSciences LLC. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 18 

SECTION 1: APPENDIX 3. Product Use Guide 

Following is a draft Product Use Guide that includes information on Enlist soybeans, herbicide 

product use, and weed resistance management practices which will be finalized prior to product 

launch. 

Dow AgroSciences

Product Use Guide

for EnlistTM Soybeans 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 19 

Stewardship Overview

Dow AgroSciences is committed to promoting the responsible use and stewardship of its products 

throughout the product life cycle. Consistent with its ongoing stewardship programs and practices, Dow 

AgroSciences has implemented comprehensive stewardship measures for EnlistTM soybeans and the 

herbicides that are part of the EnlistTM Weed Control System and Enlist soybeans.

This Product Use Guide (PUG) details requirements and recommendations for the planting of Enlist 

soybeans and the proper use of Enlist DuoTM herbicide featuring Colex-DTM Technology. This Product 

Use Guide is not a pesticide product label. It is intended to provide additional information and to highlight 

approved uses from specific product labels. Read and follow all precautions and directions on the product 

labels and any supplemental labeling for Enlist Duo herbicide featuring Colex-D Technology, Dow 

AgroSciences Authorized Herbicide Product(s), as well as any other pesticide products. As a grower 

planting Enlist soybeans, you must be both familiar with and follow the Technology Use Agreement 

(Agreement) and this associated Product Use Guide.

Dow AgroSciences’ Technology Use Agreement

NOTE: YOU MUST HAVE A VALID, EXECUTED TECHNOLOGY USE AGREEMENT ON FILE WITH 

DOW AGROSCIENCES TO LEGALLY OBTAIN, PLANT AND GROW SOYBEANS THAT CONTAIN 

DOW AGROSCIENCES’ ENLIST TRAIT.

Failure to comply with the terms of the Agreement or this PUG can result in your losing the privilege to 

grow seed containing the Enlist technology. You must communicate all applicable terms, conditions and 

restrictions on your EnlistTM soybeans to all persons and entities possessing or taking an interest in your 

EnlistTM soybean crop and/or the grain therefrom. You may complete the Agreement online at 

traitstewardship.com or obtain a copy by calling 877-4-TRAITS (877-487-2487) or contacting your seed 

provider.

By signing the Agreement, you receive a limited-use license for commercialized, authorized Enlist 

soybean seed, and to apply Dow AgroSciences’ Authorized Herbicide Products. You will also receive the 

most current PUG and other periodic updates relating to Enlist soybeans. 

By purchasing and using Dow AgroSciences technologies and traits under the Agreement, you reaffirm 

your commitment to the Agreement you signed, and to follow this PUG and herbicide product labels. The 

seed you purchase is for your use and cannot be given, sold or otherwise transferred to others who have 

not signed an Agreement and for which you have not informed Dow AgroSciences of such transfer. In 

addition, you cannot transfer Dow AgroSciences technologies and traits to anyone outside of the United 

States.

Compliance Monitoring

Dow AgroSciences will monitor compliance with the Agreement and Product Use Guide through surveys 

and on-farm assessments. Upon request by Dow AgroSciences, growers must provide information 

regarding the location of fields planted with Enlist soybeans and the herbicides applied to these fields. 

Failure to follow these stewardship requirements may result in additional education and training, 

monitoring, and/or loss of access to the technology.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 20

EnlistTM Soybean Varieties

Dow AgroSciences continues to collaborate with leading soybean breeding programs to 

develop high-yielding EnlistTM soybean varieties for growers. Enlist soybeans confer 

tolerance to 2,4-D and glufosinate, and are stacked with the glyphosate trait. This offers 

growers the benefits of tolerance to in-crop applications of Enlist Duo and other Dow 

AgroSciences’ Authorized Herbicide Product(s) to reduce weed competition. 

Coexistence

Soybeans are a naturally self-pollinated crop. If the grower desires to use or market this crop separately 

from general commodity use, fields should be planted at a sufficient distance away from other crops to 

prevent cross-pollination and mechanical mixture during harvest. 

Crop and Grain Marketing Stewardship

Dow AgroSciences is a member of Excellence Through Stewardship® (ETS). Dow AgroSciences’ 

products are commercialized in accordance with ETS product launch stewardship guidance, and Dow 

AgroSciences’ Product Launch Stewardship Policy. 

Direct grain produced from Enlist soybeans to appropriate markets as necessary. Any crop or material 

produced from this product can only be exported to, or used in, processed in or sold in countries where all 

necessary regulatory approvals have been granted. It is a violation of national and international law to 

move material containing biotech traits across boundaries into nations where import is not permitted. Talk 

to your grain handler or product purchaser to confirm their buying position for this product.

For further information about your crop marketing options, contact Dow AgroSciences at 877-4-TRAITS 

(877-487-2487). Information regarding the regulatory and market status of agricultural biotechnology 

products can be found at: biotradestatus.com.

Weed Management

Repeated use of herbicides with the same mode of action can lead to selection for resistant biotypes 

within the larger population of weeds. The key to controlling existing resistant weeds and slowing the 

development of new resistant weeds is to diversify and reduce selection pressure on the weed population 

while still maintaining high levels of weed control that limit weed seed production. 

Diversification of weed management strategies can be accomplished by integrating several proven 

practices for weed control, such as:

1. Rotate crops and cultural practices to allow for a wider range of weed control practices.

2. Start with a clean field, using either a burn-down herbicide application or tillage and scout fields 

before and after herbicide application.

3. Use the correct herbicide product at the right rate and time and apply herbicide mixtures with 

different modes of action.

4. Control weeds early when they are relatively small. Rotate herbicides that have different modes 

of action and use residual herbicides that have different modes of action.

5. Use new commercial, weed-free crop seed and clean equipment before moving from field to field 

to minimize spread of weed seed.

6. Control weed escapes and prevent weeds from setting seeds. Incorporate other herbicides and 

cultural practices as part of the herbicide-tolerant cropping systems where appropriate.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 21

Use of Enlist DuoTM Herbicide with EnlistTM Soybeans

Enlist soybeans contain patented genes that provide tolerance to 2,4-D, and glufosinate. Enlist soybeans 

are also stacked with the glyphosate trait. Enlist Duo herbicide contains the active ingredients 2,4-D 

choline and glyphosate dimethlyamine. 

Enlist DuoTM Herbicide with Colex-DTM Technology

Crop Enlist Soybeans

Active Ingredients 2,4-D Choline and Glyphosate DMA

Modes of Action Group 4 and Group 9

Formulation Soluble Liquid

Signal Word Warning

Use Rate in-Season Applications within the anticipated range of use rates: 2.5 – 4.75 pt/A

Surfactants/Oils Not Recommended

Application Timing Post-emergence to weeds

Sprayer Nozzles Coarse or Very Coarse spray 

Spray Volume 10-15 gpa

Rain Fast

Heavy rainfall soon after application may wash off this product from 

the foliage. A repeat application may be required for adequate 

control.

*Read the Product Label for complete details

Weed Control with Enlist Duo Herbicide 

The lower dosages given on the Enlist Duo label will be satisfactory for young, succulent growth of 

sensitive weed species. For less sensitive species and under conditions where control is more difficult, 

the higher dosages will be needed. Apply Enlist DuoTM when weeds are young and actively growing, per 

the label directions. 

The product label for Enlist Duo contains the approved directions growers must follow for products 

labeled for use over Enlist crops including but not limited to: weed management information, application 

equipment requirements, product use directions, restrictions and precautions, and other product 

information. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 22

The Program Approach

A program approach including Enlist Duo herbicide aids in the management of weed resistance, reduces 

weed competition during critical crop growth stages and improves the overall consistency of weed control. 

It eliminates competition from a broad spectrum of early season grass and broadleaf weeds. The mode 

of action classification system of the Weed Science Society of America (WSSA) lists 2,4-D as a Group 4 

growth regulator herbicide (synthetic auxin) and glyphosate as a Group 9 herbicide (inhibitor of ESPP 

synthase). 

• The recommended weed control program for EnlistTM soybeans is a PRE application herbicide 

product containing at least two non-Group 4/Group 9 modes of action, followed by a POST application of 

Enlist Duo herbicide. If a second POST application of Enlist Duo is required, it must occur at least 12 

days after the first application, per the product label.

Read and follow product label, as well as follow state and local requirements related to application of 

pesticides. 

Drift Management 

Susceptible Plants 

Do not apply under circumstances where spray drift may occur to food, forage, or other plantings that 

might be damaged or crops thereof rendered unfit for sale, use or consumption. Avoid contact of 

herbicide with foliage, green stems, exposed non-woody roots of crops, desirable plants and trees 

because severe injury or destruction may result. Small amounts of spray drift that may not be visible may 

injure susceptible broadleaf plants. Before making an application, please refer to your state’s sensitive 

crop registry (if available) to identify any commercial specialty or certified organic crops that may be 

located nearby. Commercially grown tomatoes and other fruiting vegetables (EPA crop group 8), 

cucurbits (EPA crop group 9), and grapes are particularly sensitive to drift from this product. Do not apply 

when wind direction favors off-target movement onto these crops.

Apply Enlist DuoTM herbicide only with properly calibrated ground application equipment using appropriate 

carriers.

Boom Height 

To minimize spray drift potential, use the minimum nozzle height recommended by the nozzle 

manufacturer based on configuration of the spray boom. 

Spray Volume 

Use a spray volume of 10-15 gallons or more per acre for ground equipment and apply with calibrated 

ground equipment. Do not apply less than 10 gallons total spray volume per acre. Where applicable, 

state regulations specifying minimal spray volumes must be observed. 

In general, increase spray volume as crop canopy, height and weed density increase to obtain adequate 

spray coverage.

Nozzle Selection

Proper spray nozzle selection plays a critical part in minimizing the potential for physical drift. Use low drift 

nozzles, according to the American Society of Agricultural and Biological Engineers (ASABE) S-572 

standard, that produce a coarse to very coarse spray and are designed for herbicide application. Ultra 

coarse droplet sizes may result in decreased weed control and increased crop injury.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 23

Wind Speed

Drift potential is lowest at wind speeds less than 10 mph. Target applications at wind speeds greater than 

3 mph but less than 10 mph. Do not apply at wind speeds greater than 15 mph.

The product should not be applied at wind speeds less than 3 mph where temperature inversion or stable 

atmospheric conditions could exist. 

Temperature and Humidity

When making applications in low relative humidity, set up equipment to produce larger droplets to 

compensate for evaporation. Droplet evaporation is most severe when conditions are both hot and dry.

Setbacks 

Setbacks for Enlist DuoTM herbicide are directional meaning they would only apply downwind of 

the spray application. Apply this product only if the wind direction favors on-target deposition and there 

are no sensitive areas (including residential areas, bodies of water, known habitat for non-target species, 

non-target crops) within 250 feet downwind. Local terrain can influence wind patterns. The applicator 

should be familiar with local wind patterns and how they affect drift.

Setback Distances: [Distances will not be finalized until EPA label is approved]

Setback Distance*: Allow setbacks (buffer zones) upwind of sensitive area (e.g., residential areas, 

bodies of water, known habitat for threatened or endangered species, and sensitive non-target crops 

other than those listed above) according to the following:

Wind Speed

(mph)

Spray Boom <24 Inches

Above Canopy

(ft)

Spray Boom >24 Inches

Above Canopy

(ft)

<5

5 – 10 [pending regulatory approval]

10 – 15

*If a coarse or very coarse droplet classification cannot be maintained, an upwind setback of 250 feet 

from sensitive areas must be observed. 

Mixing Instructions

This product mixes readily with water. Mix spray solutions of this product as follows:

1. Fill the mixing or spray tank with the required amount of clean water. If addition of ammonium sulfate is 

desired to enhance performance of the product, see the Ammonium Sulfate section of the herbicide 

product label.

2. Add the specified amount of this product near the end of the filling process and mix well. During mixing 

and application, foaming of the spray solution may occur. To prevent or minimize foaming, use a 

commercial defoamer or avoid the use of mechanical agitators, and/or terminate by-pass and return lines 

at the bottom of the tank.

Note: Use approved anti-back siphoning devices where required by state or local regulations to avoid 

siphoning back into the carrier source.

Adjuvants (except Ammonium Sulfate) 

Enlist Duo contains drift control technology. The use of adjuvants and drift control additives with Enlist 

Duo herbicide with Colex-D Technology can have a negative impact on stability and application 

performance. The addition of some adjuvants may result in increased crop injury, decreased weed 

control, and/or increased potential for spray drift. 

If an adjuvant or drift control additive is desired, it must be tested for compatibility with Enlist Duo 

herbicide. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 24

Tank Mixing with Other Products

Some herbicides, fungicides, micronutrients and insecticide products may require drift management and 

application settings that differ from Enlist DuoTM herbicide. Additionally, the formulation components of 

some products may contain inert ingredients that negatively affect the low-drift properties offered with 

Enlist Duo with Colex-D Technology. If these settings are in conflict with the management 

recommendations in this Product Use Guide, these products cannot be tank-mixed with Enlist Duo 

herbicide.

Restrictions

Refer to the label for specific planting restrictions, weed height and use information for annual and 

perennial weeds. During the growing season following application, do not replant fields with crops other 

than those labeled for use with 2,4-D and glyphosate.

Recordkeeping

As part of good farm management practices, maintain detailed spray records, including: 

• Field location and number of acres sprayed

• Date of application, start time, and finish time 

• Herbicide sprayed and application rate

• Nozzles used and operating pressure

• Travel speed and application rate

• Air temperature and relative humidity

• Wind speed and direction

• Sprayer and boom cleanout

Sprayer and Equipment Cleanout

To avoid injury to desirable plants, properly clean equipment used to apply this product before 

reuse or using the equipment to apply other chemicals.

If the crop following the application of Enlist Duo is an application to glyphosate-tolerant corn: rinse the 

spray equipment with clean water to at least 10 percent of the total tank volume and spray the solution 

out of the spray tank through the boom.

If the application immediately following Enlist Duo is to any other crop, use the triple-rinse sprayer 

cleanout procedure for Enlist DuoTM herbicide below:

• Completely drain the spray system, including lines and spray boom, for at least five minutes. 

• Fill the container with clean water to at least 10 percent of the total tank volume and circulate the 

solution through the entire system so that all internal surfaces are contacted for at least 15 minutes to 

complete the first rinse of the application equipment. Spray the solution out of the spray tank through 

the boom. 

• Completely drain the spray system, including lines and spray boom, for at least five minutes; remove 

and clean filters and strainers.

• Fill the container with clean water to at least 10 percent of the total tank volume. During the second 

rinse, tank cleaning agents may be added at the manufacturer’s recommended rates. Circulate the 

solution through the entire system so that all internal surfaces are contacted for at least 15 to 20 

minutes. 

• Completely drain the spray system, including lines and spray boom, for at least five minutes. 

• Fill the container with clean water to at least 10 percent of the total tank volume and circulate the 

solution through the entire system so that all internal surfaces are contacted for at least 15 minutes to 

complete the third rinse of the application equipment. Spray the solution out of the spray tank through 

the boom. 

• Completely drain the spray system, remove nozzle tips and strainers and clean them separately.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 25

Resources

• Enlist website: Enlist.com

• Trait Regulatory and Market Status: biotradestatus.com

• Trait Stewardship: traitstewardship.com

• Weed Resistance Assessment Tool: weedtool.com/

• Weed Resistance Management Training: soygrowers.com/WRM/default.htm

Contact Us

If you have questions about proper handling and use of these products or if you become aware of 

potential misuse or incidents involving these products, please call 877-4-TRAITS(877-487-2487).

Stewardship

Dow AgroSciences is a founding member of Excellence through Stewardship® and is a Responsible 

Care® Company.

 

Patent Statement 

This Seed is protected under one or more U.S. patents. Grower is provided a limited license under 

the Technology Use Agreement to purchase Seed from Seed Seller and to plant Purchased Seed to 

produce a single commercial crop in the United States. Grower is NOT permitted: (1) to supply, 

transfer, license or sublicense any Seed or Dow AgroSciences’ Sourced Technology to any other 

person, entity or other third party for planting or any other purposes; (2) to save or use any seed 

produced from Seed for planting by Grower or any other third party; or (3) to use or allow others to 

use Seed or any plant material produced from Seed for crop breeding, seed production, research 

(including, without limitation, agronomic testing or generation of comparative data against seed 

containing Third-Party Trait Technology), or generation of regulatory approval data. 

Trademark Statement

®TMColex-D, Enlist and Enlist Duo are trademarks of The Dow Chemical Company (“Dow”) or an 

affiliated company of Dow. ®

The Roundup Ready 2 Yield Logo is a registered trademark of Monsanto 

Technology LLC. Always follow weed resistance management, grain marketing and all other 

stewardship practices and pesticide label directions. Roundup Ready crops contain genes that 

confer tolerance to glyphosate herbicides. Glyphosate herbicides will kill crops that are not tolerant to 

glyphosate. B.t. products may not yet be registered in all states. Check with your seed representative 

for the registration status in your state. ®

Excellence Through Stewardship is a registered trademark of 

Biotechnology Industry Organization. ®

Responsible Care is a registered service mark of the American 

Chemistry Council. Components of the Enlist Weed Control System have not yet received regulatory 

approvals; approvals are pending. The information presented is not an offer for sale. Enlist Duo is not 

yet registered for sale or use as a component of the Enlist Weed Control System. Always read and 

follow label directions.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 26 

SECTION 2: ESTIMATE OF HERBICIDE VOLUME AND IMPACT ON 

ENVIRONMENTAL LOAD OF HERBICIDES WITH THE 

INTRODUCTION OF ENLIST SOYBEAN (DAS-68416-4) 

Summary 

Dow AgroSciences (DAS) has submitted a petition to the United States Department of 

Agriculture (USDA)’s Animal and Plant Health Inspection Service (APHIS) for the 

determination of nonregulated status for DAS-68416-4 soybean, which provides tolerance to 

the herbicides 2,4-dichlorophenoxy acetic acid (2,4-D) and glufosinate. 

The deregulation of DAS-68416-4 soybean will usher in a new era of weed control by improving 

existing weed control practices and introducing new modes of action in soybean production. 

Soybean varieties containing the DAS-68416-4 trait will be crossed with soybean varieties that 

contain a glyphosate-tolerant trait to produce a breeding stack. Thus, the commercially offered 

varieties will have tolerance to 2,4-D, glufosinate and glyphosate. Various scenarios based on 

different input assumptions have been constructed to estimate potential volumes of 2,4-D, 

glyphosate and glufosinate on commercial soybeans that contain DAS-68416-4 and other 

herbicide tolerant traits. These scenarios cover the range of realistic, expected use patterns based 

on an understanding of market dynamics and DAS breeding development options. The results of 

this analysis show, that when actual use patterns and market dynamics are taken into 

consideration, the increased volume of 2,4-D in soy will be a 6-9 fold increase, with an 

extremely conservative estimate of 14 fold. This is in sharp contrast to speculations that have 

been cited publicly which claim increases of hundreds to even thousands fold, but are based on 

speculation and not an understanding of true market and herbicide use dynamics. Recent studies 

indicated that other available herbicide use would increase similarly to what is projected for 2,4-

D if DAS-68416-4 soybean is not available to help control glyphosate-resistant and other hardto-control weeds. 

The projected environmental loading of herbicide use in response to the growing emergence of 

glyphosate-resistant weeds as previously discussed is reviewed. Additionally, the ecological 

assessment of pesticides in light of new projected volumes is addressed from a regulatory 

perspective. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 27 

Estimate of Herbicide Volume and Impact on Environmental Load of 

Herbicides with the Introduction of Enlist soybean (DAS-68416-4) 

Relevant to DAS-68416-4 Draft EA Section 4.4.2, 5 

Executive Summary 

The introduction of DAS-68416-4 soybean (Enlist

TM

 soybean) and Enlist Duo

TM

herbicide will 

bring a much needed new herbicide tolerant trait and vastly improved herbicide technology into 

American agriculture. The new crop trait offers tolerance to 2,4-D as well as tolerance to the 

herbicide glufosinate, combining proven broadleaf weed control with a new mode of action for 

control of problem weeds in soybean. The new trait will be stacked with existing glyphosate 

tolerance traits to enable the continued use of the extremely popular and beneficial glyphosatetolerant technology and help control existing populations of glyphosate-resistant and hard-tocontrol weeds and prevent further emergence of glyphosate-resistant weeds. 

To accompany this new crop trait technology a new herbicide offering, featuring the novel 2,4-D 

choline salt in a premix with glyphosate, has been developed and is planned for sale (pending 

applicable registrations) under the trade name “Enlist Duo”. Combining the features of the 2,4-D 

choline salt with new developments in proprietary formulation and manufacturing science has 

resulted in a 2,4-D herbicide product with significantly reduced potential for drift and volatility 

as well as decreased odor and better handling properties. 

To first look at the herbicide rates used on a single acre, a recent study modeled several farms 

in the key soybean growing areas [7]. The study found that when the average Enlist Duo 

herbicide use rates were compared to the average use rates of the top alternate, currently 

available herbicides popular for controlling glyphosate-resistant weeds, the use of Enlist Duo 

on DAS-68416-4 soybean would have a similar per acre environmental load of herbicides 

compared to the currently available programs. 

To realistically estimate the total 2,4-D volume increase across the country that may occur with 

Enlist soybeans and Enlist Duo, the following scenarios were developed based on realistic and 

expected application rates and use patterns, with conservative (bias towards over-predicting) 

assumptions on adoption rates. 

Scenario 1 assumes growers will only apply Enlist Duo to DAS-68416-4 soybean where 

growers are facing or actively trying to prevent the establishment of glyphosate-resistant 

weeds. Additionally this also assumes that all farmers with soybean acres that have 

glyphosate-resistant weeds will plant DAS-68416-4 soybean and will use Enlist Duo 

herbicide. The projections indicate an approximate six fold increase in 2,4-D use in 2020 

compared to the volume of 2,4-D currently used on soybeans. 

Scenario 2 assumes that all acres of DAS-68416-4 soybean would receive applications 

of Enlist Duo, regardless of weed control need, and thus relies on estimates of the 

projected market share of the DAS-68416-4 soybean. These projections estimate an 

approximately nine fold increase in 2,4-D use compared to what is currently used on 

conventional soybean. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 28 

Scenario 3 assumes that all current glyphosate-tolerant soybean acres except those with a 

directly competing technology would be planted with varieties that also contain the DAS68416-4 trait. This estimation of adoption rate exceeds likely projections but provides an 

upper confidence level on 2,4-D volume. While DAS-68416-4 soybean will be stacked 

with a glyphosate-tolerant trait, it is impractical to assume that all glyphosate-tolerant 

soybeans will be stacked with the DAS-68416-4 trait due to competing offerings by other 

seed companies and the likelihood of other herbicide-tolerant soybean options. Even 

with this extreme assumption, the estimated 2,4-D volume is only a fourteen fold increase 

in 2,4-D use on soybean compared to the current use of 2,4-D on soybean. 

When actual use patterns and market dynamics are taken into consideration, more reasonable 

projections are only a six to nine fold increase, with an extremely conservative estimate of only 

fourteen fold. 

Introduction of New Technology 

A new herbicide product, to be commercialized as Enlist Duo, is currently under regulatory 

review at the Environmental Protection Agency (EPA or the Agency)1

. This product, when 

approved, will be marketed for use on DAS-68416-4 soybean. Enlist Duo is a proprietary premix of 2,4-D choline and glyphosate DMA and features Colex-D

TM

 Technology. Prominent 

attributes of this technology are a greatly reduced volatility and drift profile, very low odor and 

better handling characteristics (MRID 48862902 and 48844001). Enlist Duo is formulated as an 

approximate 1:1 ratio of 2,4-D choline:glyphosate DMA. Use directions for Enlist Duo have 

been well described in the draft Environmental Assessment for DAS-68416-4 soybean and 

documents previously submitted by DAS to EPA and USDA. 

The new Use Directions under consideration by EPA will allow a pre-emergent (burn down) 

application of 0.5-1 lb acid equivalents/acre (ae/ac) of 2,4-D (and glyphosate) and up to two 

applications (0.5-1 lb 2,4-D ae/ac each, and glyphosate) post-emergent through the 

R2(flowering) stage. Total seasonal use is limited to a total of 3 lbs 2,4-D ae/ac/season, identical 

to the current seasonal maximum use of 2,4-D on corn (conventional or Enlist corn). DAS68416-4 soybean will also tolerate applications of the herbicide glufosinate which are typical of 

existing, commercially-available glufosinate-tolerant soybeans.

 

1 EPA published a Notice of Receipt on May 23, 2012, opening up a comment period that ends on June 22, 2012. 

See 77 Fed. Reg. 30524, 30526 (May 23, 2012) (Active ingredient: 2,4-D choline salt.) Proposed Classification/Use: 

Enlist AAD–1 Soybean (Trait Code: DAS-68416-4). 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 29 

Current 2,4-D Use on Soybean 

The current EPA-approved use directions for 2,4-D on conventional soybean allows a single 

pre-plant (burn down) application of 0.35-1 lb acid equivalents/acre (ae/ac) of 2,4-D. There is 

a 7 to 30 day pre-plant restriction, depending on the application rate used during the pre-plant 

application. 

Estimates of US soybean acreage from private and public sources ranges from 74MM acres to 

approximately 79 MM acres. Current soybean acreage is estimated by USDA at approximately 

76 million acres 

(http://usda.mannlib.cornell.edu/MannUsda/viewDocumentInfo.do?documentID=1000 ). 2,4-D 

for burn down is currently used on approximately <10% of the soybean acres with a recent 

historical range from 4%-10% of soybean acreage according to USDA estimates (Plant Pest 

Risk Assessment; 

(http://www.regulations.gov/#!docketDetail;dct=FR+PR+N+O+SR;rpp=10;po=0;D=APHIS2012-0019 ). When 2,4-D is utilized in a burn down or pre-plant treatment, it is almost always 

combined in a tank mix with glyphosate or other non-selective herbicide and, when tankmixed, 2,4-D is generally recommended at the lower end of the rate range ~ 0.5 lbs ae/ac 

(http://www3.ag.purdue.edu/btny/weedscience/Documents/BurndownMadness.pdf ). 2,4-D is 

currently labeled for a single pre-plant application at 0.35 to 1 lbs ae/ac. While current 

estimates of 2,4-D volume used on soybean are not readily available in a public format, third 

party proprietary data is presented in Table 1. 

From 2008-2011, 2,4-D use as a pre-plant burn down material has grown in total acres as well 

as percentage of acres treated. This is likely a result of the increase in glyphosate-resistant 

weeds as well as hard-to-control weeds. Starting the planting season with weed free fields has 

been cited as one of many important integrated resistance management tools 

(http://www.hracglobal.com/ ). 

Table 1. 2,4-D Use on Soybean 

From third party proprietary data 

Current Glyphosate Use on Soybean 

Current glyphosate use directions approved by EPA for use on glyphosate-tolerant soybean 

allow: 

Year Total 

Acres 

Acres 

treated 

with 2,4-D 

Treated 

Acres % of 

Total 

Acres 

Total Pounds 

2,4-D 

Lbs 2,4-

D/Acre 

Total 

Applications/ 

Acre 

2008 74,404,953 5,068,628 7 2,716,207 0.54 1.01

2009 77,584,979 7,637,880 10 3,680,330 0.48 1.01 

2010 78,725,007 7,763,593 10 4,106,140 0.53 1.00 

2011 74,835,007 8,832,324 12 4,893,146 0.55 1.00 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 30 

A maximum pre-emergence application amount of 3.7 lbs glyphosate ae/ac, and postemergent applications from 0.75 to 1.5 lbs glyphosate ae/ac (total 2.25 lbs ae/ac/season). 

An additional pre-harvest application of 0.77 lbs ae/ac can be made. Total seasonal use 

rate is 6 lbs glyphosate ae/ac. 

Third party proprietary market research data indicate that the percentage of total soybean acreage 

that is planted to glyphosate-tolerant soybeans has been steady at 94%-96% over the last four 

years (Table 2). Total pounds of glyphosate applied to soybean has increased during this time 

(along with 2,4-D use, as mentioned above). There is a slight but increasing trend in the rate of 

glyphosate applied per acre but the total number of applications made per acre has remained 

steady. These application rate increases reflect the fact that farmers are experiencing the need to 

increase rates to control increasing levels of hard-to-control and glyphosate-resistant weeds. 

Additionally, the use of non-glyphosate herbicides added into the glyphosate-tolerant system has 

grown steadily since 20061

 indicating farmers are adding more inputs into controlling 

glyphosate-resistant and hard-to-control weeds. 

Table 2. Glyphosate Use on Glyphosate Tolerant Soybean 

 From third party proprietary data 

Changes in 2,4-D and Glyphosate Use Directions for Enlist Duo Herbicide 

Enlist Duo

TM

Herbicide was designed to fit with the existing EPA-approved glyphosate use 

pattern which has resulted in many benefits including reduced erosion and runoff. Glyphosate is 

expected to remain a core post-emergent herbicide due to these benefits, as well as its broad 

spectrum of weed control. Use Directions for Enlist Duo were developed to directly overlap 

with the glyphosate use pattern on soybean, so that farmers who currently use glyphosate will 

find it extremely easy to use Enlist Duo on DAS-68416-4 soybean. 

As described above, Enlist Duo herbicide is an approximate 1:1 premix of 2,4-D choline and 

glyphosate DMA, based on acid equivalents. By using Enlist Duo herbicide on DAS-68416-4 

soybean, the amount of glyphosate use could be: 

 A single 1.0 lbglyphosate ae/ac application made pre-emergence; 

 Up to two post-emergent applications each at 1.0 lbs glyphosate ae/ac. 

While DAS-68416-4 soybean growers could make additional glyphosate applications, up to the 

seasonal maximum allowed on glyphosate labels, Dow AgroSciences (DAS) expects that 

additional glyphosate applications would be unlikely due to Enlist Duo’s improved weed control, 

Year Total 

Acres 

Gly-Tol 

Acres 

Gly-Tol as 

% of Total 

Acres 

Total Pounds 

Gly 

Lbs 

Gly/Acre 

Total 

Applications/ 

Acre 

2008 74,404,953 71,592,624 96 95,398,687 1.32 1.58 

2009 77,584,979 73,219,835 94 96,415,627 1.30 1.55 

2010 78,725,007 74,059,182 94 102,162,527 1.38 1.58 

2011 74,835,007 71,734,538 96 100,121,452 1.40 1.54 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 31 

current glyphosate use on soybean, the growing use of foundational herbicide (preplant) 

programs, the adoption of other products with additional modes of action, and other cultural 

mechanisms for weed control. 

The EPA-approved label directions for use of 2,4-D on soybean currently allows a single preplant application of up to 1.0 lbs ae/ac. No post emergent applications are currently approved as 

conventional soybeans are not tolerant to 2,4-D. 

With the Enlist Weed Control System and use of Enlist Duo herbicide, possible 2,4-D 

choline use on DAS-68416-4 soybean could be: 

 A single ~1.0 lb 2,4-D ae/ac application made pre-emergence; 

 Up to two post-emergent applications each up to ~1.0 lbs 2.4-D ae/ac. 

Thus, use of Enlist Duo herbicide would provide for a total possible seasonal use of up to 3 lbs 

ae/ac of 2,4-D choline (or 6 lbs ae/ac of both 2,4-D and glyphosate actives) on DAS-68416-4 

soybean (Figure 1). 

Glufosinate Use on Soybean 

Glufosinate is a nonselective glutamine synthetase inhibiting herbicide that is used to control 

grasses, sedges and broadleaf weeds. Since it is a nonselective herbicide it would injure or kill 

crop plants that it contacts. Several crop plants have been modified by inserting a gene that 

produces and enzyme which detoxifies glufosinate by converting the herbicide into a non-active 

form. To date glufosinate tolerant soybeans, corn, canola and cotton have been commercialized. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 32 

Due to its nonselective activity, glufosinate has a weed management spectrum similar to 

glyphosate and its use has grown, particularly in areas with glyphosate-resistant weeds 

(http://southeastfarmpress.com/cotton/glufosinate-herbicide-shortage-sparks-controversy ). 

Soybean is a member of the broadleaf family and as such is extremely sensitive to glufosinate 

with minute quantities causing severe injury or death to conventional soybean plants. DAS68416-4 soybean is tolerant to glufosinate at current commercial application rates used for 

glufosinate- tolerant broadleaf crops. 

Glufosinate tolerance in Enlist soybean enables use of glufosinate as a herbicide on 

commercially grown soybeans but also provides use as a selection agent in breeding programs 

and seed amplification. 

Bayer Crop Science has registered glufosinate for use on glufosinate tolerant crops including 

soybean. Ignite 280 SL Herbicide (EPA Reg. No. 264-829) is a commercially available 

glufosinate containing herbicide with directions for use on glufosinate tolerant crops, including 

soybean. 

Tolerance to glufosinate offers an alternative mode of action to glyphosate for the broadspectrum control of weeds in soybean. Glyphosate is a strong nonselective herbicide that 

controls both grasses and broadleaved weeds, but reports in the science literature indicate that 

thirteen weed species have developed resistance to glyphosate in the US

(http://www.weedscience.org/In.asp ). To date, only Italian Ryegrass has been reported as 

resistant to glufosinate in the US and is located in Oregon. However, this population of Italian 

Ryegrass also appears tolerant to glyphosate. 

Glufosinate tolerant soybeans are a more recent introduction than glyphosate-tolerant soybeans. 

The number of acres planted to glufosinate tolerant soybeans has grown steadily but is still a 

very small fraction of total soybean acres. Average seasonal use rate is about a half pound per 

acre with just over 1 application per acre made. Glufosinate can also be used as a pre-plant (burn 

down) treatment on conventional and glufosinate tolerant soybean, however volume estimates 

for this use have a high degree of uncertainty. For the years 2009-2011only a total of 46,000 lbs 

were used in a preplant treatment and 75% of those pounds were used in 2011. 

Glufosinate is a non-selective herbicide similar to glyphosate with a wide spectrum of 

susceptible grass and broadleaved weeds. With over 90% of the soy acres planted to glyphosatetolerant varieties it would appear that glufosinate offers a viable alternative particularly to 

farmers facing glyphosate-resistant weed problems. However, based on the low adoption rates 

of glufosinate tolerant soybeans, it appears that farmers may favor the glyphosate system. Other 

than a longer time of experience with the glyphosate-tolerant system, a review of the respective 

labels indicates that glufosinate may need to be applied to smaller weeds with finer droplet sizes 

and larger carrier volumes to achieve adequate control. Glyphosate translocates readily 

throughout the plant whereas glufosinate has limited mobility in the plant, thus requiring better 

coverage for control (hence the larger carrier volumes and smaller droplet sizes). 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 33 

Table 3. Postemergent Glufosinate Use on Glufosinate Tolerant Soybeans 

Year Total Acres Glu-Tol 

Acres

Glu-Tol as 

% of Total 

Acres

Total Lbs of 

Glufosinate 

Lbs 

Glu/Acre

Total 

Applications/ 

Acre

2008 74,404,953

2009 77,584,979 208,577 0.3 68,751 0.46 1.17

2010 78,725,007 892,476 1.1 452,163 0.52 1.25

2011 74,835,007 997,423 1.3 521,200 0.53 1.18

From third party proprietary data 

Changes in Glufosinate Use with Enlist Weed Control System 

No changes in glufosinate use directions would be needed. Whether used as a selection agent or 

as a herbicide, the use directions (application rates and timings) would remain the same, 

however, there may be some regulatory actions necessary to enable the use of glufosinate on 

Enlist soybeans

2,4-D Choline and Glyphosate proposed Use on DAS-68416-4 Soybean 

Third-party proprietary market research demonstrates that approximately 98% of glyphosatetolerant soybean acres receive at least one glyphosate application (burn down and/or post 

emergent). A small population of farmers (~4%) that purchase glyphosate-tolerant soybeans 

elect not to make a post-emergent glyphosate application. The market research also indicates 

that only 22% of planted soybean acres currently receive a burn-down (pre-plant or preemergence) herbicide application. 

Utilizing the historically consistent data from the current and broad use of glyphosate on 

soybean (Table 2) plus field trial data on weed control with various herbicide application rates, 

DAS has estimated that farmers who grow DAS-68416-4 soybean will use an average of 0.875 

lbs 2,4-D ae/ac/application with an average of 1.54 applications per season (includes burn 

down and post emergent). The application rate (0.875 lbs 2,4-D ae/ac) is the midpoint between 

the medium and high rates allowed on the Enlist Duo label and is consistent with the 

glyphosate rate needed for weed control. As Enlist Duo contains an ~1:1 ratio of 2,4-D and 

glyphosate nearly identical rates of glyphosate will be applied.

Estimating total acres of DAS-68416-4 soybean planted and the use of Enlist Duo herbicide on 

that soybean has many inherent accuracy limitations, and it is difficult, if not impossible, to 

make any such predictions with certainty. Nevertheless, DAS has derived three scenarios to 

estimate the potential use of 2,4-D in DAS-68416-4 soybean after deregulation and 

commercialization: 

2,4-D: Scenario One. The first scenario assumes that growers will only apply Enlist Duo to 

DAS-68416-4 soybean where growers are facing or actively trying to prevent the establishment 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 34 

of glyphosate-resistant weeds. Additionally this also assumes that all farmers with soybean 

acres that have glyphosate-resistant weeds will plant DAS-68416-4 soybean and will use Enlist 

Duo herbicide (a very aggressive assumption due to other weed control options available). 

Using third party market data, DAS has estimated that 5% of US soybean acreage had 

glyphosate-resistant weeds in 2010, and that the percentage would grow to 10% of soybean 

acreage by 2015 and to 30% by 2020 (Figure 2). This is consistent with, but less aggressive 

than, predictions made by other others, (see Foresman, Figure 2, also

http://phys.org/news203697204.html ).

Figure 2. Projected corn and soybean acres infested with glyphosate resistant weeds. 

Sources: 

Foresman, C. 2009. Syngenta Resistance FighterTM 

Message Board. http://blog.syngentaus.com/blogs/ask_the_expert/archive/2009/04.aspx Accessed January 16, 2011.

Dow AgroSciences LLC.

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 35 

Assuming that minimal additional acreage would be treated to prevent glyphosate-resistant 

weeds from becoming established, and using the assumptions set forth above regarding total 

soybean acres, application rates and applications per season, the following formula was used to 

calculate total lbs of 2,4-D ae that might be used on DAS-68416-4 soybean: 

76MM acres x 30% resistant weeds (in 2020) x .875 lbs ae/ac/application x 1.54 

applications/season = 31MM lbs 2,4-D ae per year. This represents an approximate 6 

fold increase in 2,4-D use in 2020 compared to the volume of 2,4-D currently used on 

conventional soybean. 

2,4-D: Scenario Two. The second scenario assumes, for purposes of this discussion, that all 

acres of DAS-68416-4 soybean would receive applications of Enlist Duo, regardless of weed 

control need, and thus relies on estimates of what the projected market share of DAS-68416-4 

soybean will be: 

DAS sells soybean seed through its subsidiary seed companies, i.e., Mycogen Seeds, Renze 

Seeds, Dairyland Seed, Pfister Seeds, Brodbeck Seeds, Triumph Seed, Prairie Brand Seed and 

Hyland Seeds. Through these subsidiaries, DAS currently has <3% of the market share for 

soybean, markets for which DAS-68416-4 soybean could be introgressed. At this time, DAS is 

not planning to breed DAS-68416-4 soybean into all of its soybean varieties, so DAS-68416-4 

soybean would occupy less than DAS’s current < 3% of the market. However, for purposes of 

this estimate, 3% will be used as a minimum potential DAS-68416-4 soybean acreage. 

DAS is interested in and is pursuing licensing agreements with additional soybean seed 

companies to breed DAS-68416-4 soybean into a licensee’s soybean germplasm. To date, two

licensing agreement have been made representing ~35% of the market. Through natural growth 

and these licensing arrangements it is reasonably possible that, at maturity, approximately 45% 

of the soybean germplasm could have the Enlist trait. Together with DAS’s market share, for 

purposes of this estimate, we therefore assume DAS-68416-4 soybean could ultimately be bred 

into soybean varieties planted on up to 45% of the total soybean acreage. 

Due to the technical aspects of soybean seed breeding, rapid improvement of germplasm and 

stacking with other traits, this level of adoption of DAS-68416-4 soybean is estimated to take 5-

10 years to reach maturity (maturity in 2018-2023), which is consistent with other current 

herbicide tolerant traits. Application rates of 2,4-D are as described above: an average of 0.875 

lbs ae/ac/application with 1.54 applications per year. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 36 

Utilizing the data and assumptions stated in this scenario, the estimated range of acreage and 2,4-

D volume can be estimated as follows: 

76MM acres x 45% market share x 100% DAS-68416-4 soybean acres treated x 0.875 

lbs ae/ac/application x 1.54 estimated applications per DAS-68416-4 soybean acre = 

46,084,500 lbs 2,4-D ae per year. This represents approximately an 9X increase in 2,4-D 

use compared to what is currently used on conventional soybean. 

2,4-D: Scenario Three: The third scenario assumes that all current glyphosate-tolerant soybean 

acres would be planted to hybrids that also contain the DAS-68416-4 soybean trait. This is a 

high estimation of adoption rate but provides an upper confidence level on 2,4-D volume. DAS68416-4 soybean will be stacked with a glyphosate-tolerant trait but it is impractical to assume 

that all glyphosate-tolerant traits will be stacked with DAS-68416-4 soybean due to competing 

offerings by other seed companies and the likelihood of other herbicide-tolerant soybean options. 

Due to one developing technology that will be a direct competitor to the Enlist Weed Control 

System, at least 32% of the market will not contain the DAS-68416-4 soybean trait. Therefore, 

24,320,000 acres can be subtracted from the 76MM acre total soybean acreage. Thus, 52MM 

acres of the 76 MM total soybean acres are considered planted to a variety containing the DAS68416-4 soybean trait. Using the same application information and other assumptions used in the 

previous two scenarios, the 2,4-D volume can be estimated as follows: 

52MM glyphosate-tolerant acres x 100% DAS-68416-4 soybean acres treated x 0.875 

lbs ae/ac/application x 1.54 estimated applications per DAS-68416-4 soybean acre = 

70,070,000 lbs 2,4-D per year. This represents a 14-fold increase in 2,4-D use on 

soybean compared to the current use of 2,4-D on conventional soybean. 

Glufosinate Proposed Use on DAS-68416-4 Soybean 

Given the recent introduction of glufosinate tolerant soybeans and the very small market 

share they have achieved in the last four years it is understandably difficult to predict 

glufosinate volumes for DAS-68416-4 soybean. This is accentuated by the commercial 

offering of Enlist Duo herbicide which contains glyphosate. Glyphosate and glufosinate 

would compete for the same spot in a herbicide program and with 2,4-D adding the control of 

glyphosate-resistant weeds there is little room left to rationalize use of glufosinate. However 

that does not preclude its use and it does offer a valuable alternative mode of action. 

Therefore a scenario was developed that 10% of the acreage containing DAS-68416-4 

soybean would receive glufosinate treatments consistent with how glufosinate is currently 

being used on glufosinate tolerant soybean. 

Glufosinate Use in Soybean: This scenario assumes that glufosinate will be used on 10% of 

the acres containing DAS-68416-4 soybean trait and receive glufosinate treatments equal to 

what is used today on glufosinate tolerant soybean. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 37 

76MM acres x 45% market share x 10% of acres treated x 0.53 lbs ai/ac (from Table3) = 

1,812,600 lbs glufosinate. This is ~3.5 fold increase compared to what is currently used 

on all glufosinate tolerant soybeans. 

Environmental Loading of Herbicides Used on Soybean 

DAS has conducted an analysis to determine the anticipated impact on environmental loading of 

herbicides resulting from the use of 2,4-D choline on DAS-68416-4 soybean. Specifically, this 

analysis looked at the environmental load of herbicides applied on glyphosate-tolerant soybean 

and soybeans to control glyphosate-resistant and hard-to-control weed biotypes [7]. The top 

currently available herbicide programs (excluding just increasing the rate of glyphosate alone) 

that are currently being recommended to control glyphosate-resistant weeds in soybean under 

scenarios representative of different key soybean-growing regions were compared to projected 

use of Enlist soybeans and Enlist Duo herbicide. While the range of rates of these currently 

available alternate programs and the ones for Enlist programs overlapped, when the average of 

the Enlist program rates were compared to the average of all of these top alternates, the analysis 

indicated that the use of 2,4-D on herbicide tolerant DAS-68416-4 soybean would marginally 

increase the per acre environmental load of herbicides compared to the top, currently available, 

non-glyphosate alternative programs. Several of the currently available alternatives for use on 

soybeans are used at extremely low rates, thus the apparent increase in volume for 2,4-D when 

compared to these alternatives. It should be recognized that weed resistance is increasing for 

many of these alternative chemistries so their use rates may be expected to increase or their use 

may be discontinued depending upon the severity of resistance development.

In DAS-68416-4 soybeans, the analysis indicated that the use of 2,4-D on herbicide tolerant 

DAS-68416-4 soybeans will vary from a reduction in one scenario of 0.10 lbs ae/ac to an 

increase in others of up to 0.65 lbs ae/ac, with an average increase across all scenarios of only 

0.3 lbs, compared to the use of currently registered alternative non-glyphosate herbicides. The 

results in soybeans differ from a similar exercise for corn (previously submitted) because many 

of the non-glyphosate herbicide alternatives for control of broadleaf weeds in soybeans are very 

low rate products (examples: carfentrazone, cloransulam, clorimuron, flumioxazin, fomesafen, 

sulfentrazone). Management of glyphosate-resistant and hard-to-control weeds with current 

non-glyphosate herbicide alternatives is, however, complicated by widespread resistance to ALS 

and triazine herbicides and developing resistance to PPO inhibitor and HPPD inhibitor 

herbicides.

A more recent study has been published that broke the country into six regions to assess the 

impact on total herbicide use with the introduction of DAS-68416-4 soybeans and DAS-40278-9 

corn as well as a developing cotton trait (See appendix 5 this submission). The report depicts a 

rapidly growing increase in herbicide use to combat resistant weeds out to 2020. Several 

scenarios for corn, soy and cotton were developed with varying levels of adoption for Enlist corn 

(DAS-40278-9), soy (DAS-68416-4) and cotton (not yet submitted). Under low adoption 

scenarios for DAS-40278-9 and DAS-68416-4 total herbicide use is projected to be reduced by 

4% (17 million pounds) compared to the volume used with the adoption of these two new traits. 

Under high adoption scenarios, the reduction in total herbicide volume is very substantial. 

Adoption of these traits with the accompanying 2,4-D use will result in as much as 92 million 

pounds less total herbicide use. The reduction in total herbicide use is based on displacement of 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 38 

those herbicides that will be used in an expanding manner with the introduction of these new 

traits.

Ecological Assessment of Herbicide Use on Soybean 

The EPA is the regulatory agency responsible for the review and approval or denial of all 

pesticide registrations. It is a violation of federal law for pesticides to be sold or distributed 

without an EPA registration. The Agency uses a risk assessment process in its registration 

decisions, evaluating risk based on exposure and hazard, for both humans and ecological 

organisms. EPA cannot register the use of a pesticide, or amend an existing registration to add a 

new use, unless the use of the pesticide meets the statutory “no unreasonable adverse effects” 

standard, i.e., EPA can only register new pesticides or pesticide uses if the use of that pesticide in 

accordance with the EPA-approved label will cause no unreasonable adverse effects on human 

health or the environment. 

In order to make its registration decisions, the Agency develops exposure assessments that 

characterize the potential environmental exposures that may result from the use of a 

pesticide. EPA uses the results of environmental fate studies, in combination with modeling 

work and pesticide use information to characterize the environmental fate of the pesticide in 

question. 

The Agency also uses modeling work to conservatively predict potential impacts on surface and 

ground water. This modeling work is used not only for environmental risk evaluations but is 

also an input parameter into dietary risk evaluations for humans (providing the drinking water 

component for dietary assessments). 

The results of the environmental fate work enable EPA to determine where a pesticide and its 

metabolites and degradates will go in the environment (air, water, soil), how long they will 

persist, and in what quantities. Based on study, model, and use information, the Agency then 

develops estimated environmental concentrations (EECs), which are compared to the toxicity 

endpoints of ecotoxicology studies for risk assessment purposes. EEC values are based on 

the maximum allowable application rate(s) for a pesticide even though typical application 

rates are lower than the maximum. 

As in the case of risk assessments for humans, EPA scientists use the most sensitive toxicity 

endpoints for ecotoxicology studies for risk assessment purposes. Using EECs based on 

maximum application rates and the most sensitive toxicity endpoints ensures that EPA risk 

assessments for wildlife are conservative and protective. 

EPA uses risk quotients (RQ’s) and levels of concern (LOC) for acute and chronic risk to 

wildlife to quantify and characterize risk assessments for plants and animals. RQ’s are ratios of 

EEC values over toxicity endpoints. The Agency uses different LOCs for non-endangered and 

endangered species. If planned use rates and use techniques result in RQ values that exceed 

LOCs, EPA may conduct a more refined risk assessment to better characterize risk. The Agency 

also considers how to mitigate potential risks, which may require changes in application rates 

and techniques, or may otherwise limit the use of the pesticide. 

EPA assessments of potential impacts on wildlife and the environment are designed to be 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 39 

conservative and protective. The Agency wants to be cautious in its assessments and would 

rather overstate than understate risk concerns. Each intended use pattern (e.g., soybean, 

soybeans, consumer use) is evaluated. Agency environmental and ecological assessments are 

designed to cover each particular use of a pesticide (e.g., soybean) regardless of whether all 

soybean acreage is treated or only a portion of the acreage is treated (much more typical). Thus, 

even if the percent crop treated increases, the EPA assessments are still valid. 

2,4-D has an extensive history of safe and effective use. It has been thoroughly reviewed and 

reregistered by all major regulatory agencies in the world within the last ten years. Recently 

(April 2012), the EPA denied a petition to cancel the tolerances and registrations for 2,4-D based 

on toxicological hazard. The Agency issued a resounding denial of that petition, affirming that 

2,4-D posed no unreasonable risk when used as directed [8]. 

Summary 

The introduction of the Enlist Weed Control System and Enlist Duo herbicide will provide a 

much needed additional weed control tool to soybean farmers in American agriculture. The 

Enlist Weed Control System offers a novel mechanism of herbicide tolerance in combination 

with multiple modes of action– factors which have been cited by the National Academy of 

Sciences and the Weed Science Society of America as key components to an effective resistant 

weed management plan. The introduction of herbicide tolerant crops has helped enable the 

growing practice of no-till agriculture which has resulted in dramatic reductions in soil loss 

through erosion, made farming much more efficient, reduced trips across the field with resultant 

fuel and equipment savings, and enabled farmers to proficiently farm more acres [7]. Projected 

increased volumes of 2,4-D ranged from six to 14-fold with the adoption of Enlist soybeans. The 

volume increase is largely driven by the Enlist system enabling post-emergent use in soybean 

which is not currently available. 

This exercise depicts the current use of 2,4-D in conventional soybean and the expanded use of 

2,4-D choline introduced in Enlist Duo herbicide with the adoption of Enlist soybean and the 

Enlist Weed Control System. Additionally, estimates on the use of glyphosate and glufosinate in 

DAS-68416-4 soybean are portrayed. While growers will get improved weed control 

performance they will also benefit from the additional attributes of Enlist Duo herbicide, 

particularly the reduction in off-target movement potential via drift or volatility. These 

improvements help keep the herbicide on the treated field, further reducing risk to the 

environment and ecological organisms. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 40 

SECTION 3: 2,4-D OFF-TARGET EXPOSURE AND SENSITIVE CROPS

Relevant to DAS-68416-4 Draft EA Section 2.1.2, 2.2.3, 2.3.2, 4.2.2, 5 

Federal and state regulation of off-target pesticide movement

EPA is the federal agency vested with the authority and responsibility for regulating the sale, 

distribution and use of pesticides, including herbicides such as 2,4-D. EPA registers or approves 

a pesticide for one or more uses only after determining that the product will not cause 

unreasonable adverse effects on the environment – the statutory test for registration under 

FIFRA. When EPA approves the registration of a pesticide, it approves a particular product for a 

particular use or uses under specified conditions (including composition, application methods, 

usage rates, and protective measures) and specifies the language that must appear on the label of 

the pesticide product that sets forth those conditions and limitations. If a pesticide product is 

used in a manner that is inconsistent with its labeling, the user is subject to federal and state 

enforcement action. When making its registration decision, EPA specifies the data and 

information it needs to support that registration. Among the data EPA requires are those relating 

to off-target pesticide movement including, e.g., spray drift and volatilization (40 C.F.R. Part 

158, Subparts L and N). 

Federal law requires EPA to periodically review existing pesticide registrations to ensure that 

they meet the FIFRA standard for registration (the "no unreasonable adverse effects" criteria of 

FIFRA) under current scientific standards. EPA specifically addressed issues regarding off-site 

pesticide movement of 2,4-D in EPA’s 2005 Reregistration Eligibility Decision (RED) for 2,4-D, 

which incorporated major label revisions to products containing 2,4-D. These revisions included: 

• lower limits for spray droplet size; 

• prohibitions on spraying at wind speeds greater than 15 mph, spraying with a wind 

direction that is not favorable to on-target deposition, or spraying with sensitive nontarget crops within 250 feet downwind; 

• a prohibition on spraying at wind speeds of less than 3 mph if there are temperature 

inversion conditions, or stable atmospheric conditions at or below nozzle height; 

• a prohibition on spraying where sensitive crops might otherwise be susceptible to drift; 

• restrictions on boom length and spray release height for aerial applications, and nozzle 

height for ground boom applications; 

• lower limits on application rates and total applications per year for specific crops; and 

• compliance with any state and local laws that are more stringent (e.g., California, areas of 

which have seasonal limitations on use of 2,4-D)[9]. 

EPA determined the use of the then-existing formulations of 2,4-D to be eligible for 

reregistration with those label restrictions.

As mentioned above, states also regulate the use of pesticides, including herbicides. A number 

of states have passed laws to specifically address spray drift[10]. These laws may include 

penalties and/or restrict application methods, require prior notification, impose buffer zones, etc., 

as each state has deemed appropriate. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 41 

Additional EPA actions to address spray drift and volatility 

In addition to registering individual pesticides, EPA also regularly assesses the safety of 

pesticide use more broadly, and has repeatedly addressed issues associated with off-target 

pesticide movement. Some of these efforts include: 

• In 2009, EPA developed and issued for public comment a draft guidance document (PR 

Notice) on Pesticide Drift Labeling to provide guidance to pesticide manufacturers on 

labeling statements concerning pesticide drift, and to inform the public of EPA’s policies 

with regard to pesticide drift. EPA continues to work with stakeholders to finalize this 

guidance.

• For many years EPA has contributed funding to support education and training programs 

on drift management. EPA provides annual funds to states to support pesticide applicator 

training programs, many of which include educational material on drift management, and 

EPA has contributed to other educational programs, such as the National Coalition on 

Drift Minimization educational video and CD-Rom, the National Pesticide Applicator 

Certification Core Manual, and the National Agricultural Aviation Association’s 

Professional Aerial Applicator Support System (PAASS) to support their training and 

education programs to reduce drift incidents. 

• EPA encourages pesticide applicators to use all feasible means available to them to 

minimize off-target drift. To support this goal, EPA has stated its intent to work with 

applicators, agricultural extension agents, registrants, environmental groups, and other 

interested stakeholders to collect and develop information on best management practices 

(BMPs) to reduce off-target drift for specific application methods and crop sector 

combinations. These guidance documents will be consolidated by EPA and made 

available online. 

• OPP and the EPA’s Office of Research and Development are developing a new voluntary 

program, the Drift Reduction Technology (DRT) Program, which encourages the 

development, marketing, and use of application technologies, verified to significantly 

reduce spray drift. 

• EPA has also taken action to address issues around pesticide volatility. In December 

2009, EPA convened the FIFRA Scientific Advisory Panel (SAP) to examine scientific 

issues associated with field volatilization of conventional pesticides, focusing on 

methodologies by which bystander inhalation could be measured. 

Additional information relating to EPA’s actions to address spray drift may be found at its 

website at http://www.epa.gov/pesticides/factsheets/spraydrift.htm. 

Existing precautions against off-target exposure 

Despite federal and state controls and the best efforts of applicators, off-target pesticide 

movement occasionally damages neighboring crops. Crops may be exposed to pesticide 

volatility or drift from a variety of sources, including public right of way uses for road 

maintenance and utilities, and agricultural uses[11]. Crops that have the potential for damage 

due to exposure to a particular pesticide are considered sensitive crops. Sensitive crop growers 

use a number of approaches to protect their crops from off-target exposure. Location of where 

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DAS Comments to APHIS-2012-0019
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the crop is grown is a key consideration; sensitive crop growers may choose to plant in fields that 

are sheltered or protected from potential exposure, and are not immediately adjacent to 

conventional crops2

. Buffer zones and vegetative barriers are often used as a no spray zone 

between a sensitive area and a crop being sprayed. A buffer zone may be a vegetative barrier 

consisting of groves, hedge rows, wind breaks, pastures, or even the grower’s own conventional 

crops. Vegetation planted in strategic lines can reduce the extent of spray drift of agricultural 

chemicals by filtering out spray droplets in air passing through their foliage[12]. In some cases, 

growers are able to select a sensitive crop variety that is less sensitive to pesticides that are 

commonly applied to neighboring areas. Modified cultural practices, including timing of 

operations, are another approach that can be used to protect against off-target exposure[13]. 

Sensitive crop growers may avoid exposure in right of way areas by posting signs and making 

arrangements with government road crews or utility companies to do their own maintenance of 

easements and road ways near their sensitive crops. Similarly, neighboring farms can be notified 

of the presence of sensitive crops that require protection from herbicide spray drift and volatility. 

Since applications of herbicides are increasingly being made by custom applicators, signage 

placed near field entrances alerting operators to the presence of sensitive crops and that no sprays 

are allowed, are also used. Alternatively, sensitive crop growers may notify the local coops and 

applicators directly. There are also tools available on the internet for growers to register 

sensitive crop fields so that pesticide applicators can easily locate registered sites before they 

spray using a Google MapsTM interface[14]. 

If crop damage occurs, affected growers can seek compensation by a variety of mechanisms. 

The pesticide applicator may have insurance to cover such losses. State pesticide enforcement 

bureaus are notified to view and document the damage. In some states, the applicator may be 

subject to fines or other penalties[10]. The crop damage may also give rise to claims for legal 

damages in private lawsuits. 

Potential off-target pesticide impacts on organic crops 

Growers of organic crops may also face economic damages from off-target pesticide movement, 

even if their crops are not damaged. If a certifying agent tests a crop grown under organic 

production and the test reveals the presence of residues from a pesticide not approved for use 

under the National Organic Program (NOP), the crop may not be sold as organic if the residue is 

present at a level greater than five percent of the EPA tolerance for the detected prohibited 

residue (7 CFR 205.671). A grower whose organic crops were subject to off-target pesticide 

movement that resulted in residue levels greater than five percent of the EPA tolerance could 

then lose the organic premium he may otherwise have obtained for his crop. While some 

certifying agents have refused to allow organic production on fields that have been the objects of 

spray drift, a recent court decision found this three year ban on organic production following 

spray drift to be inconsistent with the NOP (Johnson v. Paynesville Farmers Union Cooperative 

Oil Co., 2012 WL 3101667 (Minn.) at 16). 

 

2 U of IL Extension. Reducing Pesticide Drift. University of Illinois Extension and Illinois Department of 

Agriculture

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DAS Comments to APHIS-2012-0019
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In finalizing the NOP, USDA described the following in regards to grower’s responsibilities to 

protect against chemical drift (65 FR 80556): 

Drift has been a difficult issue for organic producers from the beginning. Organic operations 

have always had to worry about the potential for drift from neighboring operations, particularly 

drift of synthetic chemical pesticides. As the number of organic farms increases, so does the 

potential for conflict between organic and nonorganic operations. 

 It has always been the responsibility of organic operations to manage potential contact of 

organic products with other substances not approved for use in organic production systems, 

whether from the nonorganic portion of a split operation or from neighboring farms. The organic 

system plan must outline steps that an organic operation will take to avoid this kind of 

unintentional contact. 

When we are considering drift issues, it is particularly important to remember that organic 

standards are process based. Certifying agents attest to the ability of organic operations to follow 

a set of production standards and practices that meet the requirements of the Act and the 

regulations. 

All of the preventions discussed above are available to organic growers and many are required 

by the NOP as part of their organic production plan. Similarly, insurance and legal recourse may 

be available to organic growers who lose premiums as a result of spray drift.

2,4-D and off-target movement

One of the herbicides that DAS 68416-4 soybean has been engineered to tolerate is commonly 

known as 2,4-D. 2,4-D is a synthetic plant growth regulator (auxin) that has been registered for 

use in the US as a broadleaf weed herbicide since 1948.[15] 2,4-D is absorbed through the 

leaves and is translocated to the meristems of the plant. Uncontrolled, unsustainable growth 

ensues, causing stem curl-over, leaf withering, and eventual plant death. Thus, any inadvertent 

contact to an adjacent broadleaf crop plant, through drift or volatility, has the potential to 

produce very noticeable physiological symptomology. 

As of 2005, EPA had registered over 600 end-use products containing 2,4-D.[15] Throughout 

the period 2001-2007, 2,4-D remained the #1-ranked herbicide for industrial, commercial, 

governmental, home and garden use, with a total annual usage for these applications in the range 

24-33 million pounds.[16] Although from 2001 to 2007 its ranking as a herbicide for 

agricultural use fell from #4 to #5, annual usage was in a similar range: 28-33 million pounds in 

2001 and 25-29 million pounds in 2007. 

Since it was introduced in 1948, there have been reports of 2,4-D adversely affecting non-target 

broadleaf food and feed crops, such as cotton, grapes and tomatoes, growing in the vicinity of 

target crops.[17] Such incidents have been linked to drift of spray droplets (especially through 

aerial spraying) or drift of vapors formed by volatilization of the 2,4-D itself.[18] Drift is the 

physical movement of spray droplets moving off-site as a chemical application is made. Under 

certain conditions, the potential for physical drift from an application site to adjacent non-target 

environments is possible for all types of pesticide spray applications. This is an applicationrelated phenomenon independent of the chemical pesticide, which may be influenced by the 

formulation ingredients and spray mix additives. Volatilization refers to the transformation of a 

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DAS Comments to APHIS-2012-0019
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liquid or solid pesticide into a gas. The extent of volatilization is dependent on properties of the 

chemical and herbicide formulation, and environmental factors such as air temperature, wind 

speed, and relative humidity. Volatilized pesticides can be carried by air currents potentially 

leading to off-target exposure. 

Increased control of drift and volatilization across pesticides has been achieved with proper 

equipment setup and attention paid to climatic conditions at the time of application. University 

extension agencies have been especially prominent in developing and disseminating “Good 

Application Practices” to minimize drift. Additionally, pesticide label restrictions, state pesticide 

regulations, nozzle technology and manufacturer stewardship programs have helped to develop 

and establish application practices that minimize the potential for off-target exposure. 

2,4-D is currently formulated as an ester or amine salt. Attributions of volatility to 2,4-D have 

largely been associated with the esters, particularly short chain esters. Early forms of 2,4-D 

included short chain esters that were favored due to rapid herbicidal activity, but these were 

relatively volatile[19]. A desire to reduce risk of off-target injury to sensitive crops, such as 

cotton, tomatoes or grapes, led to the development of longer chain esters that were notably less 

volatile, and to development of various amine salts that EPA considers to be essentially nonvolatile. The volatility of the salt forms approaches two orders of magnitude reduction compared 

to the short chain esters[20]. In the last two decades, longer chain esters have replaced the 

shorter chain esters and as a result, volatility issues have largely abated. 

New technologies for controlling drift and volatility 

DAS conducted an extensive evaluation of various salts under conditions inducing high volatility 

to identify candidates that had significantly reduced volatility and thus lowered potential for 

injury to susceptible plants. The results led to the development of 2,4-D choline salt. This novel 

form of 2,4-D has been tested in the laboratory and subsequently in field studies. Quantification 

of volatilized 2,4-D from soybean and bare soil fields demonstrated: 2,4-D ethylhexylester was 

the most volatile, with calculated loss rates of the 2,4-D ethylhexylester as much as two orders of 

magnitude greater than the 2,4-D dimethylamine (DMA) form, which is considered to be 

essentially non-volatile[21]. As detailed in materials submitted to APHIS by DAS[20], the 

choline form of 2,4-D measured as much as 50X less volatility than the DMA form and had 

dramatically less injury to a variety of crops known to be sensitive to auxin herbicides under 

confined conditions as compared to ester and amine forms of 2,4-D. 

DAS’s new product containing 2,4-D choline and glyphosate DMA (Enlist Duo herbicide) will 

make the herbicide spray droplets larger and more uniform in size compared to a standard 2,4-D 

and glyphosate tank mix application. DAS has measured a 3X improvement (reduction) in 

driftable fines (<150 μ) for both 2,4-D choline and glyphosate under field conditions using 

commercial application equipment. This validates observations made under controlled laboratory 

and wind tunnel conditions. Coupled with using the latest in drift reduction nozzles, as much as a 

10X reduction in drift was achieved compared to a standard tank mix application of the same 

active ingredients using conventional nozzles. 

Pending registration by EPA, DAS intends to market Enlist Duo Herbicide with Colex-D 

Technology, a pre-mix of the new 2,4-D choline salt and glyphosate dimethylamine with reduced 

drift and volatility characteristics, for use with DAS-68416-4 soybeans. Via a Technology Use 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
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Agreement, DAS will require growers of DAS-68416-4 soybean who choose to use 2,4-D in 

post-plant applications to purchase the 2,4-D formulation in Enlist Duo to provide this added 

protection against off-target exposure. A combination of EPA-required label restrictions, 

contractual obligations and grower education and outreach will minimize any off-target effects to 

neighboring crops caused by application of Enlist Duo to DAS-68416-4 soybeans. 

Proposed herbicide label language for Enlist Duo 

DAS has submitted to EPA for approval a proposed label for its Enlist Duo Herbicide with 

Colex-D Technology, a pre-mix of the new 2,4-D choline salt and glyphosate DMA. The first 

submission to EPA is for use on Enlist corn, DAS-40278-9, and once approved then DAS will 

submit a label amendment for the use of Enlist Duo on DAS-68416-4 soybean. DAS’s proposed 

label contains the instructions for use directly addressing the potential for spray drift and 

volatility. The same label instructions will be submitted for use on Enlist soybean, DAS-68416-

4. Of course, during its label approval process, EPA may impose additional use restrictions or 

other protective measures for corn and/or soybean. 

DAS has submitted for EPA approval the following Enlist Duo label language specifically 

addressing spray drift management: 

Spray Drift Management 

Avoid drift. Use extreme care when applying this product to prevent injury to 

desirable plants and crops. 

Do not allow GF-2726 to mist, drip, drift or splash onto desirable vegetation since minute 

quantities of this product can cause severe damage or destruction to the crop, plants or 

other areas on which treatment was not intended. The likelihood of injury occurring from 

the use of this product increases when winds are gusty, as wind velocity increases, when 

wind direction is constantly changing or when there are other meteorological conditions 

that favor spray drift. When spraying, avoid combinations of pressure and nozzle type 

that will result in fine particles (mist) which are likely to drift. Do not apply at excessive 

speed or pressure. Use of this product in any manner not consistent with this label may 

result in injury to persons, animals or crops, or other unintended consequences. 

Avoiding spray drift at the application site is the responsibility of the applicator. The 

interaction of many equipment- and-weather-related factors determines the potential for 

spray drift. The applicator and the grower are responsible for considering all these factors 

when making decisions. 

Do not aerially apply this product. 

Droplet Size 

Apply as a coarse or very coarse spray (ASABE S-572 Standard). Use drift reducing 

nozzle tips in accordance with manufacturer directions that produce a droplet 

classification of coarse or very coarse to significantly reduce the potential for drift. 

Groundboom Application 

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DAS Comments to APHIS-2012-0019
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Use the minimum boom height based upon the nozzle manufacturer’s directions. Spray 

drift potential increases as boom height increases. Spray drift can be minimized if nozzle 

height is not greater than the maximum height specified by the nozzle manufacturer for 

the nozzle selected. 

Wind 

Drift potential is lowest at wind speeds of 10 mph or less. However, many factors, 

including droplet size and equipment type, determine drift potential at any given speed. 

Do not apply at wind speeds greater than 15 mph. Note: Local terrain can influence wind 

patterns. The applicator should be familiar with local wind patterns and how they affect 

drift. 

Temperature and Humidity 

When making applications in low relative humidity, set up equipment to produce larger 

droplets to compensate for evaporation. Droplet evaporation is most severe when 

conditions are both hot and dry. 

Temperature Inversions 

If applying at wind speeds less than 3 mph, the applicator must determine if: a) 

conditions of temperature inversion exist, or b) stable atmospheric conditions exist at or 

below nozzle height. Do not make applications during a temperature inversion or stable 

atmospheric conditions. Temperature inversions restrict vertical air mixing, which causes 

small suspended droplets to remain in a concentrated cloud. This cloud can move in 

unpredictable directions due to the light variable winds common during inversions. 

Temperature inversions are characterized by increasing temperatures with altitude and are 

common on nights with limited cloud cover and light to no wind. They begin to form as 

the sun sets and often continue into the morning. Their presence can be indicated by 

ground fog; however, if fog is not present, the presence of an inversion can also be 

identified by the movement of smoke from a ground source. Smoke that layers and 

moves laterally in a connected cloud (under low wind conditions) indicates an inversion, 

while smoke that moves upwards and rapidly dissipates indicates good vertical air 

mixing. 

Drift Setbacks from Sensitive Areas 

Allow setbacks (buffer zones) upwind of sensitive area (e.g., residential areas, bodies of 

water, known habitat for threatened or endangered species, sensitive non-target crops 

other than those listed above) according to the following table. 

If a coarse or very coarse droplet classification cannot be maintained, an upwind setback 

of 250 feet from sensitive areas must be observed. 

Susceptible Plants 

Do not apply under circumstances where spray drift may occur to food, forage, or 

other plantings that might be damaged or crops thereof rendered unfit for sale, use 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
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or consumption. Avoid contact of herbicide with foliage, green stems, exposed 

non-woody roots of crops, desirable plants and trees because severe injury or 

destruction may result. Small amounts of spray drift that may not be visible may 

injure susceptible broadleaf plants. Before making an application, please refer to 

your state’s sensitive crop registry (if available) to identify any commercial 

specialty or certified organic crops that may be located nearby. 

Commercially grown tomatoes and other fruiting vegetables (EPA crop group 8), 

cucurbits (EPA crop group 9), and grapes are particularly sensitive to drift from this 

product. Do not apply when wind direction favors off-target movement onto these crops. 

State and Local Requirements 

Applicators must follow all state and local pesticide drift requirements regarding 

application of 2,4-D herbicides. Where states have more stringent regulations, they must 

be observed. 

The submitted Enlist Duo label language also requires additional measures to avoid offtarget movement and crop injury, including detailed instructions for clean-out of sprayer 

equipment, use of drift control additives, and boom and nozzle height instructions. 

Additional DAS measures to address spray drift and volatility 

As noted above, DAS will contractually require growers of DAS-68416-4 soy who wish to use 

2,4-D as an in-crop herbicide to use only Enlist Duo. This new 2,4-D technology will provide 

substantially lower volatility than any other form of 2,4-D, as well as improved drift control, low 

odor, and improved handling characteristics. 

Through its Technology Use Agreement, DAS will impose a legal and contractual obligation that 

will require all growers of DAS-68416-4 soybean to: 

• Use only EPA accepted and DAS authorized 2,4-D formulations containing Colex-D 

Technology, such as Enlist Duo, for in-crop applications to DAS-68416-4 soybean. 

• Read and follow FIFRA Pesticide Product Label directions. 

• Read and follow the Enlist Weed Control System Product Use Guide. 

• Use properly maintained and calibrated ground application equipment for Enlist Duo 

with Colex-D Technology with minimum boom heights. 

• Use nozzles that reduce the potential for physical drift of Enlist Duo with Colex-D 

Technology. 

• Follow instructions for equipment clean-out after product use. 

DAS will provide comprehensive training on its technology and portfolio of products to growers, 

dealers and distributors through a variety of formats. Education and training, reinforced through 

product profiles, technical bulletins, sales literature, direct mailing and websites will also be 

presented in multiple formats to enhance learning and mastery of core concepts related to 

stewardship to be employed around DAS-68416-4 soybean. A variety of educational formats will 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
Page 48 

be used to promote concept learning. This training will include education on spray technology 

and herbicide application, including spray quality basics, as well as spray quality of Enlist Duo, 

as well as how to minimize the potential for off-target movement of Enlist Duo. 

Other potential sources of off-target movement 

Soil Leaching 

2,4-D has a relatively short half-life and is rather immobile in the soil. In 35 recent field 

dissipation studies across the U.S., less than 5% of applied 2,4-D moved downward more than 15 

cm (6 inches). The average lowest depth detected ranged from 6 to 12 inches in soils of the 

southern United States, and 16 to 24 inches in low organic soils where greater movement would 

be expected[22]. Groundwater detections of 2,4-D, which are very rare, are largely attributed to 

direct introduction by misuse or spills at well sites[23]. Proper application and avoiding filling 

spray equipment near well heads are standard good farming practices that minimize the potential 

for leaching and work effectively for 2,4-D. 

Runoff 

Being soluble and having a low to moderate soil adsorption profile provides a moderate potential 

for 2,4-D to be carried off-site via runoff. The introduction of DAS-68416-4 soybean, on which 

Enlist Duo herbicide may be used, encourages the adoption of minimum and no-till farming[24]. 

Minimizing tillage leaves more crop residue on the soil surface. Crop residue left on the surface 

significantly reduces runoff by maintaining good soil structure which, in turn, improves the 

water penetration rate. Additionally, the crop residue slows runoff from starting, allowing time 

for water to penetrate the soil. The combined effect is a reduction in runoff leaving the field. 

Farmers are increasingly moving toward no-till practices for a variety of economic and soil 

stewardship reasons and the introduction of GT crops facilitated the adoption of no-till practices. 

DAS-68416-4 soybean can help additional farmers adopt more conservation tillage practices and 

help farmers already using those tillage practices to maintain excellent weed control. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
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SECTION 4: TRAIT STACKING IN COMMERCIAL SOYBEANS

Relevant to DAS-68416-4 Draft EA Section 5 

Introduction

Soybean breeding has an established history of safety. DAS-68416-4 soybean is expected to 

perform as any conventional or deregulated GE traits in a breeding program. DAS-68416-4 

soybean is not considered to be a plant pest; thus, no significant environmental impacts are 

expected through the use of DAS-68416-4 soybean in breeding programs and in combination 

with any of the previously deregulated GE soybean products. 

All existing and future GE soybean products entering the market have or are expected to 

satisfactorily complete an FDA consultation process established to review the safety of foods and 

feeds derived from GE crops for human and animal consumption. DAS-68416-4 soybean will be 

combined with a deregulated glyphosate tolerant trait through traditional breeding. As DAS68416-4 soybean has met FDA requirements (BNF #1241

), no impacts to public health (e.g., 

food or feed safety) are expected due to combination of DAS-68416-4 soybean with other 

conventional or deregulated GE. 

The analysis below demonstrates that the “approval in whole” and the “no action” alternatives 

are similar regarding potential cumulative impacts associated with the conventional breeding of 

DAS-68416-4 soybean with other conventional or GE soybean products. 

Discussion

The combination of more than one GE trait in a plant variety or hybrid is commonly referred to 

as a “stack”. There are two basic types of stacks, molecular stacks and breeding stacks, which 

are defined based on the way the traits are combined. Molecular stacks are created by combining 

several genes together on the same transformation vector so that the resulting individual 

transformation event expresses multiple traits. This type of stack always constitutes a new GE 

event and is subject to the same regulatory oversight by USDA’s Animal and Plant Health 

Inspection Service (APHIS) as single trait events. 

Alternatively, two or more traits may be combined using conventional plant breeding methods to 

produce breeding stacks. Breeding stacks are created by cross-fertilizing (or “cross-breeding”) 

plants containing the individual traits of interest and selecting progeny that contain both traits. 

Combining traits through breeding does not involve the insertion of new DNA into the genome, 

does not involve recombinant DNA technology [1], and is not independently reviewed by 

APHIS.

 

The stacking of traits through cross-breeding has been used for more than a century to combine 

desirable plant traits in improved lines, and it is this same process that is used today to combine 

 

1 See http://www.accessdata.fda.gov/scripts/fcn/fcnNavigation.cfm?rpt=bioListing

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DAS Comments to APHIS-2012-0019
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GE traits in breeding stacks [25]. During product development, deregulated GE traits are 

incorporated into breeding programs like any other plant trait, e.g., standability, maturity, plant 

height, etc. Plant breeders work to combine many different traits through cross-breeding, both 

native and GE traits, to produce lines with the specific qualities growers need to optimize yield.

Several GE soybean products have been deregulated or are pending deregulation by the USDAAPHIS. These include soybean traits such as phosphinothricin tolerance, glyphosate tolerance, 

glyphosate and acetolactate synthase tolerance, and insect resistance.2

DAS-68416-4 soybean may be stacked using conventional breeding with other deregulated GE 

soybean traits as well as with conventional soybean varieties. Previously deregulated GE 

soybeans and progeny from crosses of these varieties with conventional or deregulated GE 

varieties have been determined by APHIS to not present a plant pest risk or display 

characteristics that constitute a significant impact on the human environment. 

A large and growing number of stacked GE products in a variety of crops have been produced 

safely on millions of acres without incident over the past decade in both the US (over 30 

products) and in other countries3

. In 2011, 49% of the total US corn acres planted (92 M 

acres) and 58% of total US cotton planted (13M acres) contained multiple (2 or more) GE 

events (USDA-ERS, 2011)4. The overall safety of these stacked GE products is well established 

[1].

APHIS Regulatory Oversight and Authority Concerning Trait Stacks 

The Plant Protection Act (PPA) and 7 CFR Part 340 grant APHIS authority to regulate plants 

that do or may pose plant pest risks, including GE plants. Based on APHIS’s review of data 

submitted by a petitioner, APHIS may determine that a GE plant does not pose more of a plant 

pest risk than a conventionally bred plant of the same species. (7 CFR 340.6) Among the data 

on which APHIS bases such a determination of non-regulated status (deregulation) are 

Mendelian inheritance data and Chi square analysis of segregation ratios for at least two 

generations to demonstrate that the transgene is stably inserted and inherited in Mendelian 

fashion [26]. This demonstration of stable integration and heritability provides assurance that all 

general theories of plant breeding will apply equally to GE plants that have successfully 

completed this review. 

In the act of deregulating GE plants, APHIS determines that the GE plant does not pose a plant 

pest risk, and by doing so, releases that plant from the agency’s PPA and Part 340 authority. 

Thus, following deregulation, APHIS’ authority over GE stacks is no different than its authority 

over any other cross-bred plants. As long as the resulting off-spring plant is not found to pose a 

PPA risk, further APHIS oversight is neither necessary nor authorized. APHIS has previously 

described its regulatory authority over stacks as the following [27]; 

 

2

See http://www.aphis.usda.gov/biotechnology/not_reg.html. Petitions of Nonregulated Status Granted or Pending 

by APHIS 3 See http://www.biotradestatus.com for list of combined trait products that have previously been commercialized. 4 See http://www.ers.usda.gov/data/biotechcrops/adoption.htm

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019
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APHIS’ regulations at 7 CFR Part 340 do not provide for Agency oversight of GE 

varieties that are no longer subject to the plant pest provisions of the Plant 

Protection Act and 7 CFR part 340, nor over stacked varieties combining GE 

varieties that are no longer subject to the plant pest provisions of the Plant 

Protection Act and 7 CFR part 340 unless it can be positively shown that such 

stacked varieties were to pose a likely plant pest risk. 

Furthermore, other regulatory agencies have adopted similar positions regarding breeding stacks 

of previously approved GE events. As described in Pilacinski et al. [25]: 

“...regulatory agencies in some countries, including the U.S. (FDA, 2001), 

Canada (CFIA, 2004), and Australia (OGTR, 2007), have requested no additional 

regulatory data to approve combined [GE] events as long as the traits are not 

likely to interact in a manner that would affect safety and the risk assessments of 

the single events can reasonably be applied to the combined event product.”

Federal Government Statements Supporting Safety of Cross-breeding

In its policy statement setting forth its views on the safety of foods developed from GE crops, the 

United States Food and Drug Administration (FDA) spoke at length regarding the relatively low 

food safety risks posed by all forms of genetic modification, including traditional plant breeding 

and GE technology. 57 Fed. Reg. 22984 (May 29, 1992). This safety is assured, in part, by the 

careful and time-honored breeding practices of plant breeders, the multiple generations of 

breeding that takes place prior to marketing, and the long history of genetic stability in crossbred crops. The same factors hold true for the environmental, agronomic, or any other effects of 

cross-breeding, or stacking, of GE traits [28]. Specifically, FDA stated:

Plant breeding is the science of combining desirable genetic traits 

into a variety that can be used in agriculture. The desired traits can 

be broadly divided into two classes: Those that affect agronomic 

characteristics of the plant, and those that affect quality 

characteristics of the food. Agronomic characteristics include 

those affecting yield; resistance to diseases, insects, and herbicides; 

and ability to thrive under various adverse environmental 

conditions. Quality characteristics include those affecting 

processing, preservation, nutrition, and flavor. 

The genetic modification techniques used to develop new plant 

varieties constitute a continuum. Traditional breeding typically 

consists of hybridization between varieties of the same species and 

screening for progeny with desired characteristics. Such 

hybridizations only can introduce traits found in close relatives. 

Breeders have developed or adopted a number of techniques to 

expand the range of genetic variation available to them. These 

techniques introduce variation either by using mutagenesis to alter 

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DAS Comments to APHIS-2012-0019
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the genome or by introducing or modifying DNA segments, 

including DNA segments derived from other organisms. 

Mutagenic techniques include both random mutagenesis, resulting 

from treatment with chemical and physical mutagens, and 

somaclonal variation, whereby, with the use of tissue culture 

techniques, plants are regenerated from callus or leaf tissue 

explants. The regenerated plants often have properties not found 

in the progenitor plant, reflecting both preexisting cellular genetic 

differences and tissue-culture induced mutations. The mutations 

range from single gene changes to chromosomal rearrangements. 

Mutagenesis techniques are limited, however, by their inability to 

target a desired trait. Somaclonal variants also frequently are 

unstable or infertile.

Techniques for gene transfer between plants that belong to 

different species or genera fall under the general heading of 

“wide crosses.” These “crosses” have been accomplished 

using hybridization, and protoplast fusion. Traditional 

wide crosses involve hybridization between closely related 

species or genera, frequently requiring the use of special 

techniques such as embryo rescue and chromosome 

doubling to overcome physical or genetic barriers to the 

production of fertile progeny. They permit the transfer of 

genetic traits that are not present in close relatives of the 

modern plant varieties but are found in more distant wild 

relatives. Traits that confer resistance to a number of 

diseases have been introduced this way. 

All of the techniques described above require extensive 

back crossing with the parent line [FN4] to eliminate 

mutations unlinked to that responsible for the desired 

phenotype and undesirable traits in extraneous genetic 

material introduced along with that encoding the desired 

trait.

FN4 A line is a group of individuals from a common 

ancestry. It is a more narrowly defined group than a 

variety. (Breeding Field Crops, J.M. Poehlman, Van 

Nostrand Reinhold, New York, 1987). 

. . . 

Regardless of the particular combination of techniques 

used, the development of a new plant variety typically will 

require many site-years (number of sites x number of years 

of plant testing) of performance trials before introduction 

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into agricultural practice. These range from as few as 10 to 

20 site-years for some plants to 75 to 100 site-years for 

others (some 5 to 10 years). The time of evaluation and the 

size and number of sites will vary as necessary to confirm 

performance; to reveal vulnerabilities to pests, diseases, or 

other production hazards; to evaluate stability of the 

phenotype; to evaluate characteristics of the food; to 

evaluate environmental effects; and to produce the required 

amount of seed before the new plant variety can be grown 

commercially by farmers. In the course of this intensive 

assessment, individual plants exhibiting undesirable traits 

are eliminated.

Any genetic modification technique has the potential to 

alter the composition of food in a manner relevant to food 

safety, although, based on experience, the likelihood of a 

safety hazard is typically very low. 

. . . 

Virtually all breeding techniques have potential to create 

unexpected (including pleiotropic [FN5]) effects. For example, 

mutations unrelated to the desired modification may be induced; 

undesirable traits may be introduced along with the desired traits; 

newly introduced DNA may physically insert into a 

transcriptionally active site on the chromosome, and may thereby 

inactivate a host gene or alter control of its expression; the 

introduced gene product or a metabolic product affected by the 

genetic change may interact with other cellular products to produce 

a deleterious effect. Plant breeders using well established practices 

have successfully identified and eliminated plants that exhibit 

unexpected, adverse traits prior to commercial use.

FN5 Pleiotropic effects refer to multiple effects resulting from a 

single genetic change.

57 Fed. Reg. at 22985-87. 

The United States Environmental Protection Agency (EPA), which regulates GE crops that have 

been engineered to produce their own pesticide, known as plant-incorporated protectants (PIPs), 

has also assessed the food and environmental risks associated with traditional plant breeding. 

For example, EPA has stated the following in the context of exempting from EPA regulation 

PIPs produced through traditional plant breeding: 

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EPA recognized and relied on the long history of human 

experience with growing and consuming plants for food and with 

the procedures of plant breeding. Plant breeding combines the 

scientific knowledge of experimental laboratory disciplines such as 

plant physiology, plant genetics, and phytopathology into a 

practical field science that develops new plant cultivars for use in 

agriculture. EPA has used these bases of knowledge and 

experience in its estimation of exposures and hazards of the 

residues of pesticidal substances addressed by this supplemental 

notice as well as for the 1994 [rulemaking] proposal. 

EPA concluded in the 1994 proposal (59 FR 60535) that the vast 

majority of plant varieties developed by plant breeders using traits 

from sexually compatible plants produce foods that are safe for 

human consumption. This conclusion is based on the experience 

of consuming crops resulting from scientific breeding as well as 

the historical consumption of crops since the prehistorical origins 

of agriculture. These foods undoubtedly contain(ed) pesticidal 

substances (and the genetic material necessary to produce them) 

and share a history of safe consumption. In addition, appropriate 

processing procedures are widely known and are routinely used by 

consumers in preparation of food from such sources, including 

those foods which require specific processing/preparation steps to 

avoid dietary problems. 

In the 1994 proposal, EPA stated that many substances having 

pesticidal activity occur naturally at low concentrations in the 

edible parts of plants and have long been accepted as part of the 

human diet. Extensive use and experience show the safety of 

foods containing these substances. For many foods, the naturallyoccurring toxicants they may contain, some of which might be 

pesticidal in function, are known. Also, the established practices 

that plant breeders employ in selecting and developing new plant 

varieties, such as chemical analyses, taste-testing, and visual 

analyses, have historically proven to be reliable for ensuring food 

safety. That there are few documented cases of new plant cultivars 

causing food safety problems despite the large numbers of new 

varieties introduced into commerce each year, is a reflection of the 

effectiveness of this process (59 FR at 60538). 

Plant varieties for the food market have been developed by breeders 

seeking better products, higher yields, and other desirable crop 

characteristics. In this process, it has been common agricultural practice 

to move traits among sexually compatible food plant varieties as well as to 

introduce traits from sexually compatible wild relatives into plant varieties 

that are used as food plants. This type of breeding process has been used 

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on most sexually compatible crop plants, and tended to increase the extent 

of relatedness among plant varieties in agricultural crops. The 1994 

proposal is based on experience with the exposure of human populations 

to crops developed through the breeding process, i.e., crops developed 

through 50 to 100 years of scientific breeding among sexually compatible 

plant populations using Mendelian genetics. The sexually compatible, 

wild relatives of cultivated plants that are used in this process do not 

themselves necessarily have any history of human consumption but have 

safely contributed traits through sexual recombination to cultivars on the 

market. For example, wild species of tomatoes have been used, in plant 

breeding, as a source of increased resistance to economically important 

diseases in tomato (Ref. 1). Sexually compatible crop varieties of the 

same plant species are also crossed with each other to achieve better pest 

resistance in their progeny. Food plant varieties developed in this way 

have been introduced, cultivated, and consumed by humans for many 

years with very few observed adverse affects (59 FR at 60538). 

62 FR 27132, 27134-35 (May 16, 1997). 

EPA wrote earlier on the same topic:

Sexually compatible plants are more apt to share traits than are 

unrelated plants. It is a common expectation that similarity is 

associated with the degree of relatedness. Natural hybridization 

and selection have produced groups of plants which have a 

common gene pool. Generations of artificial hybridization 

practiced to produce improved crops for cultivation have tended to 

increase the extent of relatedness among elements of a broader 

segment of agricultural plants.

The practice of saving seed from desirable plants has been going 

on for thousands of years and controlled crosses to produce plant 

hybrids have been documented since the eighteenth century. Since 

the rediscovery of Mendel's work on the inheritance of traits, there 

is a base of experience of 50 to 100 years of breeding for most 

major crops. During that time, it has been common agricultural 

practice to cross sexually compatible wild relatives with crop 

plants to develop crop varieties with better pest resistance. 

Techniques such as genetic mapping reveal the presence of genetic 

loci in cultivated plants that previously were considered to be 

present only in the wild species. Sexually compatible crop 

varieties are also crossed with each other to achieve better pest 

resistance in their progeny. Because of these common practices, 

the potential for significantly different environmental exposures 

from current crop plants is likely to be low. 

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59 FR 60519, 60523 (Nov. 23, 1994). 

In developing its own regulations for GE plants, APHIS has also repeatedly recognized the crop 

safety inherent in traditional breeding programs, and excluded them from regulation: 

An examination of the literature describing the techniques used in 

genetics prior to the introduction of recombinant DNA technology 

finds that many techniques other than interspecific crosses have 

been in common use. The transfer of genetic traits by methods 

such as protoplast, cell, and embryo fusion, and mutagenesis has 

been an accepted part of genetics for some years prior to the 

development of various recombinant DNA technologies for the 

movement of genes. It would thus seem that the techniques in 

question should properly be included as a part of classical genetics, 

and excluded from the definition of "genetic engineering." 

52 Fed. Reg. 22892, 22894 (June 16, 1987) (finalizing Part 340). 

Any risk posed by the introduction into the environment of a 

regulated article under the notification procedures is likely to be 

comparable to the risks posed by plants developed through more 

traditional plant breeding techniques. Over the years, plant 

breeders have developed standard agricultural practices to address 

these risks, and the Agency believes that such practices will be 

adequate to address any risk from plants introduced under this rule. 

57 Fed. Reg. 53036, 53038 (Nov. 6, 1992) (amending Part 340) 

These century-old principles of breeding support APHIS’s 

regulatory position that cross-breeding, or stacking, of GE crops, 

through conventional breeding methods, with other sexually 

compatible plants, follows the same Mendelian patterns of 

heritability as other conventional breeding. Moreover, nothing in 

the decades of field testing and commercialization of GE crops has 

shown any indication that these theories of breeding do not hold 

true for GE plants. In short, there is no reason to believe that 

stacking, or cross-breeding, of deregulated GE plants would pose 

any health, safety or environmental risks different than risks posed 

by any other crop cross-breeding.

Stacked Trait Combinations with DAS-68416-4 Soybean 

Soybean lines that contain herbicide-tolerance traits (glyphosate) have been on the market since

1996 and have experienced broad adoption (see DAS-68416-4 soybean petition, USDA Petition 

# 09-349-01p). The adoption track record of biotechnology-derived soybean represents the most 

rapid case of technology adoption in the history of agriculture [29]. Based on USDA survey data, 

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DAS Comments to APHIS-2012-0019
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herbicide-tolerant soybeans (glyphosate-tolerant) went from 17 percent of U.S. soybean acreage 

in 1997 to 68 percent in 2001 and 93 percent in 2012 [30]. Glyphosate has provided simple, 

inexpensive, and highly effective weed control and has resulted in an increase in no-till soybean 

production, a practice that is now accepted as improving soil health and agricultural 

sustainability.

With 93% of soybean acres in the U.S. in 2009 planted to glyphosate-tolerant soybeans, typical 

cultivation and management practices used by growers today already take into account the 

management of herbicide-tolerant traits. It is anticipated that the same management practices 

used today for soybeans with the glyphosate-tolerance trait will also be appropriate for DAS68416-4 soybean.

DAS-68416-4 soybean stacked with glyphosate-tolerance traits will have the potential to 

improve weed control by allowing use of herbicide combinations or mixtures which can provide 

more consistent performance in post-emergence weed control programs, and counteract 

glyphosate “rate-creep” (steady increase in rates needed to obtain effective weed control) on 

hard-to-control weeds [31]. DAS-68416-4 soybean, which is tolerant to 2,4-D, will allow use of 

a low cost, high performance solution to reduce the escalation of glyphosate- and ALS-resistance 

in weed populations. 

DAS intends to stack DAS-68416-4 soybean with soybean that has been genetically engineered 

to be tolerant of glyphosate. APHIS has granted determinations of non-regulated status for 

multiple glyphosate-tolerant soybean products, each accompanied by an environmental 

assessment under the National Environmental Policy Act (NEPA) which, in each instance, 

supported a finding of no significant impact (FONSI). APHIS undertook an extensive 

assessment of glyphosate, and EPA’s regulation of the herbicide, in its recent Environmental 

Impact Statement prepared in association with APHIS’s determination of non-regulated status of 

GT alfalfa events J101 and J163 [32]. 

Summary

Soybean breeding has an established history of safety, and DAS-68416-4 soybean is expected to 

perform in a fashion analogous to any conventional or deregulated GE traits in such a breeding 

program. Since DAS-68416-4 soybean is not considered to be a plant pest, no significant 

environmental impacts are expected through the use of DAS-68416-4 soybean in breeding 

programs and in combination with any of the previously deregulated GE soybean products. 

All existing and future GE soybean products entering the market have or are expected to 

satisfactorily complete an FDA consultation process established to review the safety of foods and 

feeds derived from GE crops for human and animal consumption. DAS-68416-4 soybean is 

intended to be combined with a deregulated glyphosate tolerant trait through traditional breeding. 

No impacts are expected due to combination of DAS-68416-4 soybean with other conventional 

or deregulated GE. 

Based on the above analysis, the approval in whole and no action alternatives are similar 

regarding potential cumulative impacts associated with the conventional breeding of 

DAS-68416-4 soybean with other conventional or GE soybean products. 

DAS-68416-4 Soybean 

DAS Comments to APHIS-2012-0019