Supplemental Information for USDA Petition for Nonregulated Status of DAS

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Supplemental Information for Petition for Determination of Nonregulated Status

for Herbicide Tolerant DAS

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Economic and Agronomic Impacts of the Introduction of DAS

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Glyphosate Resistant Weeds in the U.S. Cropping System

The undersigned submits this information under 7 CFR 340.6 to support the determination that the article should not be regula ted under 7 CFR 340.

Submitting Company: Dow AgroSciences LLC Submitted by:

__________________________________ T. Craig Blewett , Ph.D. Regulatory Leader Regulatory Sciences & Government Affairs Dow AgroSciences LLC 9330 Zionsville Road Indianapolis, IN 46268 Telephone: (317) 337

- 4421 FAX: (317) 337

- 4649
tcblewett @dow.com

May 11 , 2011Supplemental Information for USDA Petition for Nonregulated Status of DAS

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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

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- dic hlorophenoxy acetic acid (2,4

- D) and quizalofop.

This document provides information pertaining to the economic and agronomic impact of DAS

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o Benefits of Glyphosate Tolerant Crops
o Weed Management in Glyphosate Toler ant Corn and Soybeans
o Long

- term Weed Resistance Management through Use of Herbicide Tolerant DAS

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o Economic Benefits of Dow AgroSciences Herbicide Tolerant Technology
o Impact of 2,4

- D on Herbicide Tolerant DAS

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- 4 Soybeans on the Cost and Environmental Load of Herbicides Applied on Glyphosate Tolerant Corn and SoybeansSupplemental Information for USDA Petition for Nonregulated Status of DAS

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## Economic and Agronomic Impacts of the Introduction of DAS

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TABLE OF CONTENTS

1.1 Introduction

________________________________ _____________________________ 8 1.2 Glyphosate tolerant crop Technology Adoption

______________________________ 9 1.3 Factors Influencing Glyphosate tolerant crop Techology Adoption

_____________ 10 2 Benefits of Glyphosate Tolerant Crops

________________________________ _______ 12 2.1 Enviro nmental Benefits

________________________________ _________________ 12 2.1.1 Enables conversva tion tillage with Glyp hosate tolerant crop s

________________ 12 2.1.2 Reduces soil erosion

________________________________ __________________ 13 2.1.3 R e duces greenhouse gas emission

________________________________ _______ 13 2.2 Economic Benefits

________________________________ _____________________ 14 2.2.1 Reduces chemical costs

________________________________ ________________ 14 2.2.2 Reduces fuel costs

________________________________ ____________________ 14 2.2.3 Reduces labor costs

________________________________ ___________________ 15 2 .2.4 Reduces management costs

________________________________ ____________ 15 2.2.5 Global ec onomic benefits

________________________________ ______________ 16 2.3 Yield Enhancement

________________________________ ____________________ 16 2.4 Convenience

________________________________ __________________________ 17 3 Weed Management in Glyphosate Tolerant Corn and Soybeans

__________________ 1 9 3.1 Herbicide resistance

________________________________ ____________________ 20 3.2 Oth er shifts in weed communities

________________________________ _________ 22 3.3 Potential for future spread of glyphosate resistant and hard

- to
- control weeds in glyphosate toleran t crops

________________________________ __________________ 23 3.4 Growers’ response to glyphosate resistant and hard

- to
- control weeds

__________ 28 3.5 Weed mana gement strategies to sustain glyphosate resistant cropping systems in corn and soybeans

________________________________ ________________________ 34 3.6 New tools f

or weed resistance managmenet

________________________________ 35 4 Long

- term Weed Resistance Management through Use of Herbicide Tolerant DAS

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________________________________ ________________________________ ___ 3 6 4.1 DAS

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______ 3 6 4.2 Managem ent of glyphosate resistance and hard

- to
- control we eds using herbicide tolerant DAS

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________________________________ _________________ 37 4.3 Proposed Use Pattern and Compatibility wi th Glyphosate Cropping System

_____ 39 4.4 Proactive resistance management for 2,4

- D throug h integration with glyphosate

_ 40

5 Economic Benefits of Dow AgroSciences he rbicide tolerant technology

__________ _ 4 3Supplemental Information for USDA Petition for Nonregulated Status of DAS

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6 Impact of 2,4

- D on Herbicide Tolerant DAS

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___________________________ ________________________________ 44
Conclusions______________________________

_______________________________ 44Supplemental Information for USDA Petition for Nonregulated Status of DAS

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FIGURES Figure 1.1 Adoption rates of herbicides tolerant corn and soybean in the United States

__ 9 Figure 1.2 U.S. glyphosate prices

________________________________ ______________ 11 Figure 2.1 Corn and soybean fuel consumption by t i llage type, Central Corn Belt

_____ 15 Figure 2.2 Benefits o f glyphosate tolerant crops

________________________________ _ 18 Figure 3.1 Global reports of herbicide resis tance weeds

___________________________ 20 Figure 3.2 Adoption of glyphosate tolerant crops and development of glyphosate resistant weeds in the United States

________________________________ ___________________ 21 Figure 3 .3 Glyphosate Resistant Weeds

________________________________ ________ 24 Figure 3.4 Projected corn and soybean acres infested with glyphosate resistant br oadleaf and grass weeds in the United States (excluding volunteer glyphosate resistant corn).

__ 27 Figure 3.5 Average postemergence glyphosate use rates on corn and soybeans in the United States

________________________________ ______________________________ 28 Figure 3.6 Average number of gl yphosate applications on corn and s oybeans in the United States (includes bu rndown uses)

________________________________ ______________ 29 Figure 3.7 Total pounds of glyphosate applied on corn and soybeans in the United States (includes bourndown uses)

________________________________ ___________________ 29 Figure 3.8 Preemergence non - glyphosate herbicide usage on glyphosate toleran t corn

_ 31 Figure 3.9 Preemergence non - glyphosate herbicide usage on glyphosate tolerant soybeans

________________________________ ________________________________ __________ 31 Figure 3.10 Post

- emergence non - glyphosate herbicide usage on glyphosate tolerant corn 32 Figure 3.11 Post

- emergence non - glyphosate herbicide usage on glypho sate tolerant soybeans (excludes products typically us ed to control volunteer corn)

_______________ 32 Figure 4.1 2,4

- D, quizalofop, and glyphosate applications sc hedules for DAS

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TABLES

Table 1.1 Yea r of deregulation for Glyphosate tolerant crop s

______________________ 10 Table 1.2 Percent of all soybeans planted to herbici de tolerant varieties by state

______ 12 Table 3.1 Weeds that evolved resistance to glyphosate in glyphosate tolerant crops in the United States

________________________________ ______________________________ 22 Table 3.2 Weeds reported to have increased in abundance in glyp hosate tolerant crops 25 Table 3.3 Future assumptions for glyphosate resistant weeds in corn and soybeans in the United States

________________________________ ______________________________ 26 Table 3.4 Future assumptions for glyphosate resistant weeds in corn and soybeans in the United States, Syngenta Corporation

________________________________ __________ 2 7 Table 3.5 Assessment of resistance risk by eval uation of the cropping system

_________ 35 Table 4.1 Glyphosate resistant , ALS resistant weeds, and hard

- to
- c ontrol weeds that are controlled by 2,4

- D

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1 Economic and Agronomic Impacts of the Introduction of DAS

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1 .1 Introduction Glyphosate tolerant crop A technology has driven dramatic changes in agricultural production processes while generating important economic and environmental benefits. But as some agronomists warned, the benefits of glyphosate tolerant crop s are beginning to be eroded by increasing weed resistance as well as weed population shifts to hard

- to

control weeds. Growers have begun to alter production practices to adjust for weed resistance and shifts to hard

- to

- control weed s . Unfortunately, some of these practices, particularly tillage, reverse some of the benefits gained from glyphosate tolerant crop technology. In order to preserve the benefits of glyphosate tolerant crop technology, Dow AgroSciences' herbicide tolerant DAS

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- to

- control weeds without additional tillage. In addition, DAS

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- to

- control weeds. The purpose of this paper is to demonstrate the importance of g lyphosate tolerant crop technology, briefly summarize the benefits of glyphosate resistant crop technology, describe the developing weed resistance and weed shift problem, discuss current solutions to weed resistance, provide an overview of Dow AgroSciences’ herbicide tolerant DAS

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- term solution to the development of weed resistance.

A The following definitions are applied throughout this document:

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.

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 popul ation becomes dominant in a given area.

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.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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1.2 Glyphosate tolerant crop Technology Adoption There are few technologies that have been as widely and universally adopted as g lyphosate tolerant crop s. USDA estimates that 91 percent of the soybeans planted in 2009 were glyphosate tolerant varieties (see Figure 1.1)

. 1 A t least one other source , which surveys approximately 5,000 large U.S. farms, suggests similar results. 2 In the case of corn, there is some discrepancy in the data on the percent of corn acres that were planted with glyphosate tolerant seed in 2009. USDA estimates that total herbicide resistant hybrids planted represented 68 percent of the corn acres plant ed in 2009

. 1 Estimates from proprietary surveys and Monsanto (based on seed sales) are higher, exceeding 80% of total planted area. 2, 3 In any case, the prevalence of glyphosate tolerant seed use in both corn and soybeans is very high, underscoring the i mportance of glyphosate tolerant technology

. Figure 1.1 Adoption rates of herbicide tolerant corn and soybeans in the United States

Sources: USDA's June "Acreage" Report, various issues, 2000

- 2009 1 , Fernandez

- Cornejo & McBride soybeans 1996

- 1999 4 , Duke and Powles corn 1998

- 1999 5

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1.3 Factors Influencing G lyphosate tolerant crop Technology Adoption
The historical data on glyphosate tolerant technology releases and the rate of adoption provides informative clues about the perceptions of benefits, the ease of adoption, and the general availability of the technology. Adoption of most new technologies starts off slow ly . Early adopters usually figure out if the technology lives up to claims made about it as well as how difficult the technology is to implement in the production process. In addition, availability of the technology can limit initial growth. Beyond this point the factors influencing adoption become more crop specific. It is also important to note that g lyphosate tolerant crop technology was not simultaneously introduced for all crops in the same year and subsequently adoption curves start at different points (see Table 1 .1).
The literature from the late 1990's cast s glyphosate tolerant technology mostly as a tool to enable easier management of crops : some early studies even documented yield drag in soybeans. 6 Yet in these early studies, the yield results were based on strip trials made in weed free fields which were not necessarily representative of actual farm conditions. 6 In addition, glyphosate tolerant technology was not available in the highest yielding soybean varieties at the time. USDA noted that analysts expected yield drags to disappear when the glyphosate tolerant trait was backcrossed into higher yielding parent lines. 6 Despite the early concerns of a yi eld drag , the rapid adoption of glyphosate resistant crops indicates the value farmers associated with the new technology. Table 1.1 Year of deregulation for glyphosate tolerant crops

Source: Duke and Powles, 2008. 5 By 1998, adoption of glyphosate tolerant technology in soybeans had increased, jumping from 17 to 44 percent of total soybean acreage in the United States in just one year from 1997 to 1998 (see F igure 1.1) . This rapid jump in adoption suggests that growers perceived substantial benefits from adopting the technology. Studies document that glyphosate tolerant technology provided "better, simpler, cheaper, and more flexible weed management than the conventional alternatives." 5 , 7 , 8 , 9 There appears to be a reversal in tolerant technology adoption in 2000 for corn and soybeans (see Figure 1.1)

. However, this is probably more attributable to a shift in data sources on adoption ra tesSupplemental Information for USDA Petition for Nonregulated Status of DAS

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. In 2000, glyphosate came off patent and prices slowly began to fall as generic glyphosate producers increased production. Falling glyphosate pr ices provided further incentives to adopt g lyphosate tolerant technology (see Figure 1.2 and Table 1.2). Supply issues from generic glyphosate producers in 2008 drove prices back up, but this price increase was temporary (see Figure 1.2)

. By 2004, Marr a et al., noted that g lyphosate tolerant technology continued to be adopted for soybeans despite the fact that prices of herbicides used for conventional soybeans had fallen to the point where the cost of these herbicide bundles were competitive with g lyph osate tolerant soybean s. 10 Note that the adoption growth rate in soybeans slowed after 2004, but still increased. New studies have shown that profitability is not the only driver of adoption rates. Other factors such as compatibility with the use of other herbicides , ease of use, observable in

- field results, and flexibility in application timing can drive the adoption of a new technology , and have done so here

. 11 , 12 , 13 , 14 , 15 , 16 , 17 The results an d convenience associated with g lyphosa te tolerant crop s are discussed below in section 2

. Figure 1.2 U.S. glyphosate pr ices

Source : Proprietary data source , 2009

. 2 Adoption of glyphosate tolerant corn has occurred more slowly than adoption of g lyphosate tolerant soybean s. For corn there were already several effective pre

- and post $0.00 $2.00 $4.00 $6.00 $8.00 $10.00 $12.00 $14.00 $16.00 Dollars Per Pound of Acid EquivalentSupplemental Information for USDA Petition for Nonregulated Status of DAS

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emergent weed control herbicides in place that could be effectively used for preemergence weed control. 18 In addition, glyphosate tolerant corn was not approved for import into the EU until late 2003 , thereby limiting the export market for glyphosate tolerant grain

. Table 1.2 Percent of all soybeans planted to herbicide tolerant varieties by state

Source: USDA's June "Acreage" Report, various issues, 2000

- 2009 1 2 Benefits of Glyphosate Tolerant Crops As discussed below, the use of glyphosate tolerant crops has been shown to promote the use of conservation tillage practices. “Conservation tillage” refers to the use of herbicides to control weeds before, at, or after planting, rather than tilling the soil and “plowing up the weeds” to control them. By reducing soil erosion, conservation tillage preserves topsoil, soil structure, improved water infil tration and holding capacity as well as improved water quality by reducing soil, pesticide and fertilizer run

- off. Additionally , greenhouse gas emissions are decreased by reducing tractor trips across fields, and allowing the soil to sequester carbon thro ugh increased soil organic matter.
2.1 Environmental Benefits 2.1.1 Enables conservation tillage with g lyphosate tolerant crop s Many studies have noted a linkage between the rapid adoption of g lyphosate tolerant crop s and conservation tillage practices. 4, 10, 19 , 20 , 21 , 22 The literature varies somewhat in its conclusions on causality, but there is consensus that g lyphosate tolerant crop s enable d greater adoption of conservation tillage including minimum and no

- till practices. If herbicides are used to control weeds before, at, or after planting, the need for tillage before and after planting is eliminated. The National Academy of Sciences concludes inSupplemental Information for USDA Petition for Nonregulated Status of DAS

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resistance technology and conservation tillage may represent the largest single environmental benefit of GE [Genetically Engineered] crops." 18

The American Soybean Association conducted a survey of famers in 2001 asking what factors had the greatest impact on their adoption of reduced tillage or no

- till soybeans. Fifty four percent of the survey respondents indicated that the release of g lyphosate tolerant soybean s had the greatest impact. 23 The next largest factor, with 15 percent of the respondents, was improvements in reduced till or no

- till planters. Another comparison that is a bit more striking was made by Dill, et al. in 2008. 24 The percent of g lypho sate tolerant soybean s planted via no

- till was nearly 50 percent compared with conventional soybeans at 32 percent. Conventional tillage was used on about 32 percent of g lyphosate tolerant soybean s, but nearly 50 percent of conventional soybeans. 24

Unfo rtunately the development of glyphosate resistant weeds and weed population shifts to hard

- to

- control weeds is jeopardizing the gains in conservation tillage. As noted below, i n section 3.4, increased tillage is identified as a primary grower means to con trol glyphosate resistant weeds. 5, 25 , 26

2.1.2 Reduces soil erosion When adoption of g lyphosate tolerant soybean s and corn encourages parallel adoption of conservation and reduced tillage practices, improved soil and water conservation can be obtained . Conservation and reduced tillage can increase the availability of organic matter and minerals in the soil leading to enhanced soil structure and fertility. Soil erosion and water runoff are also reduced, sustaining the productive capacity of land and min imizing surface and groundwater contamination. 20, 27 Due to improved soil moisture content and retention capacity, efficiencies in water use may also be achieved. 28 , 21, 29
2.1.3 Reduces greenhouse gas emission Increased no till cultivation enabled by g lyp hosate tolerant crop technology has two air quality impacts: reduction in fuel consumption and increased carbon sequestration within the soil. 29, 20, 21 Reduction in fuel use through less tillage as well as less intensive tillage is well documented for co nventional versus conservation tillage (see S ection 2.2. 2 below). In addition, by leaving the soil profile intact, a greater amount of organic carbon in the form of crop residue is sequestered in the soil. Sequestering more carbon in the soil leads to a reduction in green house gas (GHG) emissions. Brookes and Barfoot partitioned these GHG impacts from herbicide resistant soybeans and canola into carbon emission reductions from reduced fuel consumption and increased carbon sequestration. 30 Relative to c onventional tillage, they increased carbon sequestration by a rate of 300 kg carbon/hectare - 1 for no

- till and 100 kg carbon/hectare - 1 for reduced tillage. They describeSupplemental Information for USDA Petition for Nonregulated Status of DAS

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2.2 Economic Benefits One of the primary reasons g lyphosate tolerant crop technology has been so popular with growe rs is the strong economic incentive. The incentive s are primarily driven by lower costs of production including lower costs for chemicals, fuel , labor, and management.
2.2.1 Reduces chemical costs
Studies indicate that chemical costs for growers of g lyph osate tolerant crop s are substantially lower in part because those growers have been able to control weeds through glyphosate alone without the assistance of other herbicides until recently. 9 In 1997, USDA found that soybean herbicide costs were reduced 1 1 percent by g lyphosate tolerant crop technology in the primary growing are a of the United States 6

. In addition, when glyphosate came off patent in 2000, its price declined by 40 percent (Figure 1.2)

. In 2003, Sankula and Blumenthal found that soybean herbicide costs were reduced 53 percent by g lyphosate tolerant crop technology. 31 , 28 Slightly lower soybean herbicide cost reduction estimates of 46 percent were found by Sankula for 2005. 28, 32 In summary, overall, the introduction of glyphosate tolerant soybean resulted in a reduction in weed control costs.
2.2.2 Reduces fuel costs Energy costs are also reduced through g lyphosate tolerant crop technology. As discussed above, the expansion of conservation tillage pract ices and g lyphosate tolerant crop technology have been found to complement each other. NAS states that glyphosate can be used to "supplement or replace tillage" in controlling most weeds, reducing fuel and labor inputs. 18 In USDA's fuel simulator, fuel c onsumption is reduced by 44 percent in corn and 60 percent in soybeans by switching from conventional tillage to no

- till methods (see Figure 2.1). 33 In 2006, Mitchell et al. found that reduced tillage systems in California cotton reduced fuel use by 42 to 62 percent. 34 Sanders found similar results , with conservation tillage reducing fuel costs as much as 50 percent

. 35 Another source of fuel savings referenced in the literature is a reduction in herbicide applications. 5, 25
Reduction in tillage and spraying also results in lower farm machinery expenses. Short

term machinery repairs are lower and less usage extends the life of farm machinery , thereby reducing the long run cost of equipment. 18Supplemental Information for USDA Petition for Nonregulated Status of DAS

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Source: USDA

- NRCS, May 2010. 33

2.2.3 Reduces labor costs Labor savings result in part from reduced tillage and also fewer herbicide applications. Sanders estimates a 40 percent reduction in labor costs through conversion to

conserva tion tillage practices. 35 Jasa reports that labor was reduced from 1.22 hours per acre to 0.49 hours per acre with a shift from moldboard plow tillage to no

- till. 36
2.2.4 Reduces management costs Management costs (time and effort expended to control of weeds) are also reduced with g lyphosate tolerant technology allowing growers to farm more land or increase their hours at an off

- farm job. Recent studies have found a positive relationship between off farm income and the adoption of g lyphosate tolerant soybean s. 37 , 38 These studies concluded that a 15.9 percent increase in off

- farm household income is associated with a ten percent increase in the probability of adopting g lyphosate tolerant soybean s. Other studies have found that adoptin g g lyphosate tolerant soybean s reduces farm labor requirements by 23 percent. 39Supplemental Information for USDA Petition for Nonregulated Status of DAS

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2.2.5 Global economic benefits The reduction in costs of production at the farm level translate s directly into an aggregate reduction in costs , enabling growers to obtain the same level of production at lower costs. In economics , this corresponds to a rightward shift in the supply curve which, assuming other factors remain constant , promotes a drop in the price of soybeans and an improvement in consumer welfare. These positiv e economic impacts extend to the grower through lower production costs, to the company supplying the technology through product sales, to other co

- product sales such as seed ( the carrier of the technology in this

case ) , and to global consumers through lowe r commodity prices. 28
Many studies have estimated the economic benefits of g lyphosate tolerant crop technology , focusing on one or more of the areas realizing the economic benefits. While studies looking at the global welfare for all sectors provide the most complete picture of economic benefits, not all studies are this broad. In any case, the literature documen ts economic benefits , particularly for growers and global consumers. Brooks and Barfoot focused on the farm income benefits of g lyphosate tolerant technology . They reported global economic benefits to farm income from g lyphosate tolerant soybean s over th e 1996

- 2004 period of $9.3 billion. 29 Falck

- Zepeda estimate d the total increase in global welfare from glyphosate resistant soybeans for one year, 1997/98, at $1.06 billion. 40 Moschini et al. estimated the total global welfare from g lyphosate tolerant soy bean s for the year 2001 at $1.2 billion. 41 In 2002, Qaim and Traxler estimated the global welfare effects of g lyphosate tolerant soybean s for 2001 at $1.2 billion. 42 In a study by Trigo and Cap of the Argentine soybean industry, accumulated savings in globa l consumer spending over the 1996

- 2005 from growers in Argentina adopting g lyphosate tolerant soybean s was $26 billion. 43 Finally, in 2008, Konduru et al. estimated a total global welfare increase for all glyphosate resistant soybean adoption , including lo sses from a shift away from the minor oilseeds , of $31.4 billion over the 1996 to 2006 period. 28

2.3 Yield Enhancement The opportunity for g lyphosate tolerant crop s to boost crop yields is driven by the ability of glyphosate to better control weeds. Empirical evidence of yield enhancement through use of g lyphosate tolerant crop technology is somewhat conflicting. Many of the early studies show yield drag in soybeans , particularly in areas outside the primary soybean growing area. 42, 44 , 45 , 46 , 47 In 2 002, Marra, et al. suggested that yield drags in the early years of adoption disappeared over time as glyphosate tolerance was introduced into more elite soybean varieties. 28, 48 Other studies have shown an increase in yields with g lyphosate tolerant techn ology , particularly in the main growing region of the United States. 2, 40, 49Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- glyphosate tolerant and g lyphosate tolerant crop s 50 . Of the 1 4 studies reporting specific results for g lyphosate tolerant soybean s in developed countries, none of the studies showed a yield decrease and the average increase in soybean yields was seven percent. Only three studies reported specific results for g lyphosate tolerant soybean in developing countries, but again none of the studies showed a yield decrease and the average increase in soybean yields was 21 percent. While the sample size is too small to draw specific conclusions, these results could be

re presentative of different weed pressures in developing versus developed countries. Growers in developed countries can more easily access alternative options for effective weed control compared to developing countries where effective weed control options

m ay be more limited. 50 Therefore, the potential for yield enhancement may be greater in environments with higher weed pressures. 51 To the extent that existing weed control programs prior to g lyphosate tolerant crop technology controlled weeds, the yield imp act from adopting g lyphosate tolerant crop s may be smaller.

In S ection 3 of this report, a detailed discussion of weeds that have developed resistance to glyphosate is presented. Weed resistance and shifts in weak populations suggest the importance of com plementary systems which control hard

- to

- control weeds while allowing continued use of glyphosate in controlling the broad spectrum of weeds still susceptible.
2.4 Results and Convenience Throughout the literature , the simplicity and flexibility of g lyphosate tolerant crop s is mentioned repeatedly as one of the major benefits of this technology. 20, 52 But what exactly does that mean? First, and foremost, is the manner in which g lyphosate tolerant crop technology works. As a non

- selective broad spectr um herbicide, glyphosate will control virtually all susceptible weed species with one or two appropriately applied post emergent applications to the g lyphosate tolerant crop ( i.e

. applied after the crop has emerged )

. Contrast this simplicity with conventi onal herbicide alternatives that can involve hiring a crop consultant to prescribe a combination of herbicides appropriate to the crop with the right selectivity for the weed spectrum for each field on the farm. Second, simplicity also extends to the "ove r

- the

- top" application of glyphosate on g lyphosate tolerant crop s , allowing greater ground speed and much wider coverage in a single spraying pass in contrast to more directed spray applications for other herbicides

. 11
Third, g lyphosate tolerant crop s offer considerable flexibility at planting time. Typically, growers in the U.S. Corn Belt will plant corn before soybeans due to its longer growing season and its yield sensitivity to weather conditions at the silking stage. However, weather delays can play havoc with the planting season and make the planting window very narrow for optimal yields. G lyphosate tolerant corn and soybean s allow growers aSupplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 18 of 50 Dow AgroSciences LLC longer window for weed control since they can return to the field and spray the crop at a later date ra ther than be limited to only applying weed control at planting or early post emergence as is the case with many other herbicides . In addition, glyphosate will control larger weeds (up to 10 cm are controllable in most circumstances) , compared to other post emergent herbicides, further expanding the window for weed control. 27 Glyphosate also has no residual soil herbicidal activity allowing maximum cropping flexibility. 26
Finally, flexibility also encompasses the enabling of conservation tillage practices

. G lyphosate tolerant crop s allow weed control without tillage. By reducing the amount of tillage, labor requirements fall , allowing growers more time to complete planting in a timely manner for optimal crop yields and/or expand their farming operation t hereby reducing their fixed cost per bushel produced. 26 Brookes and Barfoot conclude d in their study that g lyphosate tolerant soybean s have enabled an expansion in second crop soybeans in Argentina due to the time savings alone from reduced tillage. They estimate the net value over variable costs of the additional second crop soybeans at $699 million in 2006. 30
Figure 2.2 Benefits of glyphosate tolerant crops

Glyphosate Tolerant Crops Complementary with reduced tillage

• Reduces soil loss

• Lowers energy usage

• Improves carbon sequestration

• Lowers greenhouse gas emissions

Convenience

• Simplifies herbicide application

• Accelerates speed of application

• Saves management time

• Increases flexibility

• Enhances production process simplicity Cost reduction

• Lowers energy costs from fewer tillage passes and less intensive tillage

• Reduces herbicide cost

• Reduces labor costs

• Lowers machinery costs

Yield enhancement

• Improves yields on farms in developing regions

• Potentially enhances yields in developed countries depending on weed pressureSupplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 19 of 50 Dow AgroSciences LLC 3 Weed Management in Glyphosate Tolerant Corn and Soybeans Proper weed control has always been a critical challenge for crop growers because weeds compete with crops for light, water and nutrients. Herbicides used in modern agricultural systems enable growers to manage most weeds across vast acreages. However, weed changes can occur in response to herbicide use as it can for other types of agricultural management decisions. Changes in weed populations begin when a subset of plants within a weed species, called a “biotype,” have a distinct genetic makeup that allows them to resist and survive a particular herbicide application. As a grower continues to use a particular herbicide without any other herbicide modes of action that are active against the resistant biotype , or doesn’t use any other weed control practices, the resistant biotype continues to survive and produce seed while susceptible biotype ( s ) of that weed are controlled. Subsequent populations of the resistant biotype will continue to increase until they are the dominant weed in the field. As detailed in the previous sections, the introduction of glyphosate tolerance into crops through genetic engineering has revolutionized crop protection. Glyphosate is a broad

spectrum herbicide with favorable environmental characteristics and effective broad

spectrum weed control that has greatly improved crop protection efficiency. The widespread adoption of g lyphosate tolerant crop s, and subsequent glyphosate use, on a large portion of the available agronomic cropland has resulted in a strong selection pressure for weed biotypes that are not controlled by glyphosate ; glyphosate resistant weeds and hard

- to

- control weeds . After a little more than a decade of use, the utility of this technology is threatened by the occurrence of glyphosate resistant and hard

- to

control biotypes of certain weed species.
G lyphosate resistant weed species such as marestail , ragweed, waterhemp and Palmer amaranth and hard

- to

- control species such as lambsquarters and morning glory species are quickly spreading through corn and soybean producing states (Figure 3.3) . The potential magnitude of the problem affects an estimated 15 to 20 million acres of corn and soybeans and presents impor t ant agronomic and economic challenges to growers and the agricultural industry (Table 3.1) . University weed scientists from across the country have warned of the impact of glyphosate resistant weeds on the profitability and sustainability of current cropping systems and believe that a higher level of stewardship is required to sustain the benefits of glyphosate and g lyphosate tolerant crop s into the future. 53 Management of the spread of hard

- to

- control and herbicide

- resistant weeds will likely guide the direction of crop production in the future. 54 Growers clearly need more effective and diverse tools to manage glyphosate resistant and hard

- to

- control weeds in order to sustain the long

- term viab ility of the g lyphosate tolerant crop ping system and preserve the benefits it provides to growers, the agricultural industry, and society.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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3.1 Herbicide resistance The evolution of herbicide

- resistant weeds is not unique to glyphosate. Currently, 195 spe cies (115 dicots and 80 monocots) have evolved resistance to at least one of 19 herbicide modes of action ( the means by which a herbicide achieves the intended effect on the plant) in at least 347 herbicide

- resistant weed biotypes distributed over 340,000 fields (Figure 3.1). 55
Figure 3.1 Global reports of herbicide resistant weeds

As discussed above in Section 1.2, c orn and soybean production in the United States was drastically altered with the introduction of g lyphosate tolerant technology in 1996 and 1998. By 2009 , producers grew glyphosate tolerant varieties and used glyphosate for weed control on approximately 95 percent and 82 percent of the soybean and corn acres, respectively. 56 The growers on these acres were generally not using other weed control practices, and the situation outlined above occurred

– weed biotypes that were not killed by glyphosate survived and reproduced. 57 In response to th e selection pressure (i.e. a reduction in the reproductive success of the glyphosate susceptible weed biotype s as a result of glyphosate treatment ) imposed by these practices , the composition and structure of weed communities in agricultural fields have been altered. 57 A total of eleven weed species have developed resistance to glyphosate in the United States. Nine of theseSupplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 21 of 50 Dow AgroSciences LLC species have evolved re sistance to glyphosate in GT crops since their introduction 13 years ago. 55 The nearly exclusive reliance on glyphosate for weed control on g lyphosate tolerant crop varieties has caused substantial changes in weed communities. Figure 3.2 shows this relationship of the adoption of g lyphosate tolerant corn and soybeans to the development of glyphosate resistant weeds

. Figure 3.2 Adoption of glyphosate tolerant crops and development of glyphosate resistant weeds in the United States

Sources : Third party proprietary data

– Iain Heap http://www.weedscience.org

. The first report in the U nited S tates of glyphosate resistance in weeds associated with a g lyphosate tolerant crop involved horseweed in Delaware. 58 Growers found it difficult to control this weed in no

- till g lyphosate tolerant soybean s once resistance evolved since tillage was not used to “plow under” any resistant biotypes. Since the initial report in 2000, glyphosate resistant populations of horseweed have been documented in 16 states throughout the Mid

- Atlantic, Mid

- South, Mississippi Delta, and Midwest states. 5 5 Since the discovery of glyphosate resistant horseweed in 2000, eight other wee d species have evolved resistance to glyphosate in g lyphosate tolerant crop s in the United States including Palmer amaranth, waterhemp, Johnsongrass, common ragweed, giant ragweed, kochia, Italian ryegrass and Johnsongrass (Table 3.1). 110%

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 11 # of Confirmed Gly - Res Weeds in U.S.

GT Soybean GT Cotton GT Corn % of Acres with GT CropSupplemental Information for USDA Petition for Nonregulated Status of DAS

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Table 3.1 Weeds that evolved resistance to glyphosate in glyphosate tolerant crops in the United States
Species Crop State Acreage*
Amaranthus palmeri (Palmer amaranth) Corn, cotton, soybean Georgia, North Carolina, Arkansas, Tennessee, Mississippi 200,000

– 2,000,000

Amaranthus tuberculatus (waterhemp) Corn, soybean Iowa, Missouri, Illinois, Kansas, Minnesota 1,200

– 11,000

Ambrosia artemisiifolia (common ragweed) Soybean Arkansas, Missouri, Kansas <150

Ambrosia trifida (giant ragweed) Cotton, soybean Ohio, Arkansas, Indiana, Kansas,
Minnesota, Tennessee 2,000

– 12,000

Erigeron canadensis
(horseweed) Corn, cotton, soybean Arkansas, California, Delaware, Illinois, Indiana, Kansas, Kentucky, Maryland, Michigan, Mississippi, Missouri, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee > 2,000,000

Kochia scoparia (kochia) Corn, soybean Kansas 51

- 100

Lolium multiflorum (Italian ryegrass) Cotton, soybean Mississippi 1000

– 10,000

Sorghum halepense (Johnsongrass) Soybean Arkansas Unknown

* Minimum and maximum acreages are based on expert judgments provided for each state. The estimates were summed and rounded to provide an assessment of the minimum and maximum acreages in the United States. These values indicate orders of magnitudes but do not provide precise information on abundance of resistant weeds and likely underestimate actual acreage because the estimates were made when the resistance was first identified. Source: Data from Heap, 2010.
3.2 Other shifts in weed communities (hard

- to
- contr ol species) The makeup of weed communities in agronomic fields is influenced by many factors in addition to herbicide use including tillage, crop rotation, soil characteristics , environment al factors , and management practices. Weeds that naturally tolerat e g lyphosate tolerant crop weed management practices are referred to as “hard

- to

- control”Supplemental Information for USDA Petition for Nonregulated Status of DAS

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weeds. As described abo v e, t he adoption of g lyphosate tolerant crop ping systems has contributed to large increases in the percentage of growers using no

- till and reduced

- till systems. 59 In response to these tillage practice changes, winter annual and perennial weed species have become more prevalent after the widespread adoption of g lyphosate tolerant crop s because they are not “plowed under” and can survive to rep roduce and spread. For example, horseweed, which behaves primarily as a winter annual weed, was rarely an economic problem in conventionally tilled fields, but has become a problem in

no

- till and reduced till fields. Weeds, like waterhemp, that continue to germinate after the last glyphosate application, escape control, and have an advantage in g lyphosate tolerant crop s. 60 Some weeds are naturally more tolerant of glyphosate, such as lambsquarters, wild buckwheat and morning glory species and have become more prevalent (Table 3.2) . Table 3.2 lists weed species that have been found to become more abundant after the widespread adoption of g lyphosate tolerant crop s excluding resistant biotypes discussed above in Section 3.1

. 3.3 Potential for future spread of gl yphosate resistant and hard

- to
- control weeds in glyphosate tolerant crops G lyphosate resistant and hard

- to

- control weeds are rapidly increasing in agricultural fields both in the number of species with resistant biotypes and the acreage infested (Figure 3.3). Tables 3.3

- 3.4 and Figure 3.3 present future assumptions for glyphosate resista nt weed development in corn and soybeans in the United States. Several common annual grass and broadleaf weeds are expected to develop resistance to glyphosate during the next five years including lambsquarters, velvetleaf, barnyardgrass and foxtail. Dow AgroSciences projects that approximately 3 0 million acres (20 percent of the 160 million total corn and soybean acres) will become infested with glyphosate resistant weeds by 2020 (Table 3.3 and Figure 3.4 ), while Syngenta projects that glyphosate resistant weeds will infest 38 million acres by 2013 (Table 3.4 and Figure 3.4). As a result, glyphosate resistant and hard

- to

- control weeds are projected to impact management decisions on nearly half of the corn and soybean acres in the United States wi thin ten years.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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### Figure 3.3 Glyphosate Resistant Weeds Change in Prevalence: 2001, 2005, 2009

Source: http://www.weedscience.orgSupplemental Information for USDA Petition for Nonregulated Status of DAS

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Table 3.2 Weeds reported to have increased in abundance in glyphosate tolerant crops Species Crop
Acalypha spp. (copperleaf) Soybean

Amaranthus tuberculatus (waterhemp) Soybean Amaranthus palmeri (Palmer amaranth) Cotton Annual grasses Cotton Chenopodium album (common lambsquarters) Soybean Iowa

Commelina communis (Asiatic dayflower) Cotton, soybean Midwest, Midsouth, Southeast Commelina benghalensis (tropical spiderwort) Cotton Southeast, Georgia

Cyperus spp. (nutsedge) Cotton
Equisetum arvense (field horsetail) Herbicide

- resistant crops

Oenothera biennis (evening primrose) Herbicide

- resistant crops Iowa

Oenothera laciniata (cutleaf evening primrose) Soybean

Pastinaca sativa (wild parsnip) Herbicide

- resistant crops Iowa Phytolacca americana (pokeweed) Herbicide

- resistant crops
Ipomoea spp. (annual morning glory) Cotton

Source: Ervin, D. E. et.al. 2010. Impact of Genetically Engineered Crops on Farm Sustainability in the United States. Committee on the Impact of Biotechnology on Farm

- Level Economics and Sustainability; National Research Council. ISBN: 0

- 309

- 14709

- 3, 240 pages, 6 x 9. h ttp://www.nap.edu/catalog/12804.html . Accessed: A pril 28, 2010.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 26 of 50 Dow AgroSciences LLC Table 3.3 Future assumptions for glyphosate resistant weeds in corn and soybeans in the United States*
Corn and Soybean Acres Today (2010) By 2015 By 2020

Glyphosate resistant weed species present or predicted Marestail Common ragweed Giant ragweed

Palmer amaranth Waterhemp

Kochia Rigid ryegrass Johnsongrass All 2010 weeds , plus Lambsquarters

Velvetleaf Barnyardgrass

Giant foxtail Goosegrass All weeds listed

in 2010 and 2015

Estimated acres infested with glyphosate resistant weeds 7.5 M acres 15 M acres 30 M acres

% infested with glyphosate resistant weeds 5% 10% 20%

Estimated % of acres on which weed management decisions are impacted by glyphosate resistant weeds 10% 20% 40%

* Future assumptions for glyphosate resistant weeds in U.S. corn and soybeans are based on a 75

- 89% probably. Source: Dow AgroSciences LLC.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 27 of 50 Dow AgroSciences LLC Table 3.4 Future assumptions for glyphosate resistant weeds in corn and soybeans in the United States, Syngenta Corporation

Category Species
Key weeds developing resistance in corn and soybean fields over a broad area of the corn belt Waterhemp Pigweed species

Horseweed Probable resistant weeds by 2010

- 2015 Foxtail Barnyardgrass Johnsongrass

Source: Syngenta Resistance Fighter TM Message Board. http://www.resistancefighter.com/about/weed

detail.aspx?Id=91163 ; Figure 3.4 Projected corn and soybean acres infested with glyphosate resistant broadleaf and grass weeds in the United States (excluding volunteer glyphosate resistant corn).

Sources:

 Foresman, C. 2009. Syngenta Resistance Fighter TM Message Board. http://blog.syngenta

us.com/blogs/ask_the_expert/archive/2009/04.aspx Accessed January 16, 2011.

 Dow AgroSciences LLC.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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3.4 Growers’ response to glyphosate resistant and hard

- to
- control weeds Glyphosate resistance and other weed shifts can reduce the effectiveness and economic benefits of g lyphosate tolerant crop systems. However, growers are reluctant to stop using g lyphosate tolerant crop s and glyphosate when faced with hard

- to

- control weed species. Despite reduced weed control, growers have constructed their farming enterprise s around glyphosate and g lyphosate tolerant crop s, and they prefer the convenience, broad spectrum control and economic benefits of using glyphosate. 57 So they prefer to increase glyphosate application rates, increase the number of glyphosate applications, use other herbicides in addition to glyphosate, and/or increase tillage to control problem weeds. Figures 3.5 and 3.6 show how glyphosate rates and the number of glyphosate applications applied on corn and soybeans have steadily increased with the widespread adoption of g lyphosate tolerant crop systems and evolution of glyphosate resistant and hard

- to

- control weeds. Figure 3.7 shows the impact of inc reasing glyphosate rates and application frequency, and the increase in g lyphosate tolerant corn acres on total glyphosate use on corn and soybeans. (Please note that the g lyphosate tolerant soybean acreage was flat from 2006

- 2009, so the increase in poun ds of glyphosate used during this time period resulted from higher glyphosate application rates and frequency. Corn acres, however, grew during this time period and account for much of the glyphosate increase.) Figure 3. 5 Average postemergence glyphosate use rates on corn and soybeans in the United States.

Source: Third party proprietary data Lb. ai/Acre

Corn Soybeans 0.9Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 29 of 50 Dow AgroSciences LLC Figure 3.6 Average number of glyphosate applications on corn and soybeans in the United States (includes burndown uses)

Source: Third party proprietary data Figure 3.7 Total pounds of glyphosate applied on corn and soybeans in the United States (includes burndown uses)

Source: Third party proprietary data No. of Glyphosate Applications

Corn Soybeans Corn Soybeans 1.75
Lb Glyphosate Applied

Corn Soybeans 120,000,000Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 30 of 50 Dow AgroSciences LLC In addition to higher rates and application frequency of glyphosate, growers have increased their use of non

- glyphosate herbicides in g lyphosate tolerant crop systems in order to introduce additional herbicide modes of action for control glyphosate resista nt and hard

- to

- control weeds. The use of preemergence residual herbicides nearly doubled, increasing from approximately 40 percent to 75 percent of the g lyphosate tolerant corn acreage and from 20 percent to 34 percent of the g lyphosate tolerant soybean a creage from 2000 to 2009 (Figures 3.8 and 3.9). During this same timeframe , the use of postemergent non

- glyphosate herbicides on g lyphosate tolerant corn more than doubled from approximately 15 percent of the g lyphosate tolerant corn acreage in 2000 to 39 percent in 2009 (Figure 3.10). Postemergent use of non

- glyphosate herbicide s on soybeans followed a slightly different pattern (Figure 3.11). Use of these herbicides on g lyphosate tolerant soybean s was approximately eight percent of the g lyphosate toler ant soybean acres in 2000 and 2001, then dipped to five percent in 2004

- 2006, and increased to 11 percent in 2009. Unfortunately, the use of non

- glyphosate herbicides does not always address weed resistance issues. Growers do not always use broad

- spectrum herbicides to supplement glyphosate , so even when utilizing these alternative modes of action, glyphosate still provides the control of certain weeds while the supplemental herbicide has no effect on those weeds. 61 In addition, growers often app ly reduced rates of non

- glyphosate herbicides , resulting in a reduced spectrum of control and frequent weed escapes. 62 , 63 Glyphosate still provides control of certain weeds when used in combination with reduced rates of non

- glyphosate herbicides.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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Figure 3. 8 Preemergence non - glyphosate herbicide usage on glyphosate tolerant corn

Source: Third party proprietary data

Figure 3.9 Preemergence non

- glyphosate herbicide usage on glyphosate tolerant soybeans

Source: Third party proprietary data 80,000,000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 40%

RR Soybean Acres Non Glyphosate Herbicide Acres % of RR Soybeans with Non Gly Herbicide 80,000,000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 80%

RR Corn Acres Non Glyphosate Herbicide Acres % of RR Corn with Non Gly HerbicideSupplemental Information for USDA Petition for Nonregulated Status of DAS

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Figure 3.10 Post

- emergence non - glyphosate herbicide usage on glyphosate tolerant corn

Source: Third party proprietary data

Source: Third party proprietary data 80,000,000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 12%

RR Soybean Acres Non Glyphosate Herbicide Acres % of RR Soybeans with Non Gly Herbicide 80,000,000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 45%

RR Corn Acres Non Glyphosate Herbicide Acres % of RR Corn with Non Gly Herbicide

Figure 3.11 Post

- emergence non - glyphosate herbicide usage on glyphosate tolerant soybeans (excludes products typically used to control volunteer corn)Supplemental Information for USDA Petition for Nonregulated Status of DAS

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Several peer

- reviewed journal articles have been published on grower response to glyphosate resistant and hard

- to

- control weeds in glyphosate resistant crops. The following literat ure review is summarized from the National Research Council report entitled “ Impact of Genetically Engineered Crops on Farm Sustainability in the United States. 18

 “Soybean growers in Delaware continued planting glyphosate

- resistant soybean even in the pres ence of widespread glyphosate resistance in horseweed. Most producers addressed the problem by applying a herbicide with a different mode of action, increasing the frequency of glyphosate applications, or using tillage before planting. Some 76 percent of growers estimated that resistance in horseweed increased their management costs by more than $2.02/acre, and 28 percent reported cost increases of over $8.09/acre.”

 “A survey of 400 corn, soybean, and cotton producers in 17 states found that most would not limit the use of glyphosate

- resistant crops when facing problematic glyphosate

- resistant weeds. Instead, producers planned to increase the rotation of herbicides, the use of tank

- mixes, or the amount of tillage. They expected that additional measures for the control of glyphosate

- resistant weeds would cost $13.90

– 16.30/acre.”

 “In an economic analysis of weed

- management costs with a hypothetical reduction of control with glyphosate in three regions of the United States, the projected cost of new resis tance

- management practices for horseweed was $12.33/acre in a cotton

– soybean

– corn rotation in western Tennessee. Additional costs were due to a shift from no

- till to conventional tillage for cotton and the need for new preplant herbicides for soybean.”

 “ The projected cost of new herbicide resistance

- management practices for waterhemp was $17.91/acre in a corn

– soybean rotation in southern Illinois; this cost resulted from use of different preemergence and postemergence herbicides for soybean.”

 “For cotton grown in Georgia, the extra cost of controlling shifts in tropical spiderwort (Commelina benghalensis), a weed that is naturally tolerant to glyphosate, was predicted to be $14.91/acre; an additional herbicide application after cotton emergence explained this cost.”

The authors of the National Research Council report concluded from these studies that the evolution of glyphosate resistance and weed shifts could lead to two important changes in practices: increased use of herbicides generally and reduction s in conservation tillage. The preceding literature review indicates that these changes will increase weed

- management costs, reduce growers’ profits, and produce environmentalSupplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 34 of 50 Dow AgroSciences LLC consequences. If widely adopted by growers, increased use of herbicides and ti llage will negate the environmental benefits achieved through g lyphosate tolerant crop systems.

3.5 Weed management strategies to sustain glyphosate tolerant cropping systems in corn and soybeans The key to controlling existing resistant weeds and slowing the development of new resistant weeds is to reduce and diversify selection pressure on the weed population while still maintaining economic levels of control. 64 This requires a planned and integrated weed management approach combining:

 Rotation of crops

-- to allow a more varied weed control program

 Rotation of cultural practices

-- to reduce reliance on herbicides

 Rotation of sequences and mixtures of herbicidal modes of action and chemistry

-

- to reduce the pressure on a specific herbicide group.

Di versification of weed

- management strategies can be accomplished by integrating several weed

- control tactics including the following: 65

 Scout fields before and after herbicide application.

 Start with a clean field, using either a burn

- down herbicide applic ation or tillage.

 Control weeds early when they are relatively small.

 Rotate herbicides that have different modes of action.

 Use residual herbicides that have different modes of action.

 Use tank

- mixes of herbicides that have different modes of action.

 In corporate other herbicides and cultural practices as part of g lyphosate tolerant crop ping systems where appropriate.

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

 Control weed escapes and prevent weeds from setting seeds.

 Clean equipment before moving from field to field to minimize spread of weed seed.

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

 Report any incidence of repeated non

- performance on a particular weed to the local crop protection chemical com pany representative, retailer, or county extension agent.
The Herbicide Resistance Action Committee (HRAC, www.hracglobal.com) prepared the tool presented in Table 3.5 to help growers assess the value of weed resistance management practices and create an effective integrated weed management program. HRAC recommends that the number of applications of a single mode of action be limited in a single growing season. Where possible, HRAC recommends use of herbicide mixtures or sequential application of herbici des of different modes of action that are active on the same target weeds. In cases of confirmed herbicide resistance, HRAC advises farmers to avoid using the herbicide to which resistance has been confirmed unless used in conjunction with herbicides with a different mode of action active on the resistant weed population.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 35 of 50 Dow AgroSciences LLC Resistance management through use of herbicide mixtures and rotation of herbicides is most effective if the partner herbicides are highly effective against the same weeds. A partner he rbicide which is only marginally effective at controlling a weed or is used at a reduced application rate (to reduce crop damage), is not expected to effectively delay resistance

. 62
Table 3.5 Assessment of resistance risk by evaluation of the cropping sy stem

Management Option Risk of Resistance

Low Moderate High

Herbicide mix or rotation in cropping system >2 modes of action 2 modes of action 1 mode of action

Weed control in cropping system Cultural, mechanical

and chemical Cultural* and chemical Chemical only

Use of same MOA per

season Once More than once Many times

Cropping system Full rotation Limited rotation No rotation

Resistance status to MOA Unknown Limited Common

Weed infestation Low Moderate High

Control in last 3 years Good Declining Poor

* Cultural control can be by using cultivation, stubble burning, competitive crops, stale seedbeds, etc. See HRAC guidelines for more details.

Source: Herbicide Resistant Action Committee. http://w ww.hracglobal.com

3.6 New tools for weed resistance management Without changes in production practices, increased weed resistance to glyphosate will likely increase weed

- management expenses for growers. Given the rapid increase in, and expansion of, glyphosate resistant weeds in g lyphosate tolerant crop s, herbicide

-Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- 9 Corn Page 36 of 50 Dow AgroSciences LLC resistance management needs national attention and requires the development and use of new, more effective weed

- management strategies and tactics. New herbicide tools are critical to manag ement of weeds with resistance to multiple modes of action.
Herbicide tolerant DAS

- 40278

- 9 corn allows the use of a new herbicide mode of action

on corn , the aryloxyphenoxyproprionates class of grass herbicides (e.g. quizalofop) and confers robust toleranc e to 2,4

- D

. This technology enables the use of a new mode of action on corn, for control of grasses, and efficacious application rates and flexible application timing for 2,4

- D. Most university recommendations for control of glyphosate resistant and ha rd

- to

- control broadleaf weeds include 2,4

- D as a control option for preplant burndown and postemergence applications in corn B

. However, corn hybrids show differing levels of tolerance to 2,4

- D so it has not been widely adopted and use rate restrictions to prevent phytotoxicity limit the spectrum of activity on weeds. 66 2,4

- D’s wide spectrum of broadleaf weed control complements glyphosate because it controls most glyphosate resistant and hard

- to

- control broadleaf weed species (Table 4.1 and Section 4.4 ). 2,4

- D will control broadleaf weeds that are resistant to other modes of action such as ALS

enzyme inhibitor and PPO inhibitor herbicides, including weeds with multiple resistance. Weed researchers are hopeful that new technologies , such as DAS

- 40278

- 9, wi ll become useful tools to help manage glyphosate resistant and hard

- to

- control weeds in order to sustain the long

- term viability of the g lyphosate tolerant crop ping system and preserve the benefits it provides to growers, the agricultural industry, and soc iety. 4 Long

- term Weed Resistance Management through Use of Herbicide Tolerant DAS

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4.1 DAS

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- 9 corn enables use of alternative modes of action to glyphosate
DAS

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- 9 corn plants have been genetically engineered to express the aryloxyalkano ate dioxygenase (AAD

- 1) protein. The AAD

- 1 protein is an enzyme with an alpha ketoglutarate

- dependent dioxygenase activity which results in metabolic inactivation of herbicides in the aryloxyalkanoate family. DAS

- 40278

- 9 corn enables tolerance to 2,4

- di chlorophenoxyacetic acid (2,4

- D) C and to aryloxyphenoxypropionate (AOPP) herbicides (“fop” herbicides).

B For example: http://www.btny.purdue.edu/Pubs/ws/ws

- 16/ C Dow AgroSciences is seeking EPA regist ration of a new 2,4

- dichlorophenoxyacetic acid (2,4

- D) product to be utilized with DAS

- 40278

- 9 corn. This proprietary choline salt of 2,4

- D has ultra low volatility, improved stability at low temperatures and improved, lower odor. In addition, Dow AgroSciences is developing technology to significantly reduce the potential for off

- target movement via spray droplet drift.Supplemental Information for USDA Petition for Nonregulated Status of DAS

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- D and fop herbicides represent two distinct modes of action that are different from glyphosate which acts through a single mode of action . 2,4

- D is a broadleaf herbicide that acts as a synthetic auxin causing uncontrolled growth and plant death. 2,4

- D is classified by HRAC as a Group O herbicide (a synthetic auxin, acts like indole acetic acid) and Group 4 in the Weed Science Society of America ( WSSA) mode of action classification scheme (a synthetic auxin, speicifc site(s) unknown)

. Each Group designation reflects a specific mode of action or how it affects the sensitive species. 67 The “fops” are grass herbicides that act by inhibiting acetyl c oenzyme A carboxylase involved in lipid and fatty acid biosynthesis. The fops are classified by HRAC as Group A herbicides (Group 1 in the WSSA mode of action classification scheme). Glyphosate is a non

- selective herbicide that acts by inhibition of 5

- en olpyruvylshikimate

- 3

- phosphate synthase (EPSPS), a key enzyme in the shikimate biosynthetic pathway. Glyphosate is classified by HRAC as a Group G herbicide (Group 9 in the WSSA scheme). 4.2 Management of glyphosate resistant and hard

- to
- control weeds u sing herbicide tolerant DAS

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- 9 corn From commercial launch, DAS

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- 9 will be stacked (the process of combining traits through traditional breeding) with glyphosate tolerance so that farmers will be able to use 2,4

- D and glyphosate together , thus simultaneously applying two different but complementary modes of action for both broadleaf and grassy weed control. Herbicide tolerant DAS

- 40278

- 9 corn enables weed resistance management practices that today are not possible. In corn varieties stac ked with both DAS

- 40278

- 9 and glyphosate tolerance, t he herbicide 2,4

- D is an ideal complement to glyphosate to provide a n exceptional pre and postemergent weed management program that is not available today and is readily adaptable to use with foundation herbicide programs . It has a similarly broad spectrum activity for control of broadleaf weeds, low mammalian toxicity, short soil residual activity, and a favorable environmental profile. Importantly, in applications to corn with tolerance to both 2,4

- D and glyphosate (DAS

- 40278

- 9 corn stacked with a glyphosa te tolerance trait through traditional breeding) , 2,4

- D can be tank mixed with glyphosate or provided as a premix that will be cost effective to use. 2,4

- D controls several key broadleaf weed speci es that are resistant to, or difficult to control with, glyphosate and ALS herbicides (Table 4.1). Mixtures of 2,4

- D with glyphosate provide control of glyphosate resistant biotypes and hard to control weeds that is superior to glyphosate alone

. Applications of 2,4

- D to DAS

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- 9 corn therefore can play an important role in managing glyphosate resistant weed biotypes. It provides a new opportunity to preserve the economic, environmental, and convenience benefits of herbicide tolerant technologySupplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 38 of 50 Dow AgroSciences LLC even in the presence of glyphosate resistance. By growing crops that are tolerant to 2,4

- D, farmers will be able to control weeds that otherwise would become an increasing problem. It will enable farmers to avoid returning to environmentally damaging we ed management practices such as tillage. Table 4.1 Glyphosate resistant, ALS resistant weeds, and hard

- to
- control weeds that are controlled by 2,4

- D

Weed Species Glyphosate Resistance /

Hard

- to
- Control Resistant to ALS Herbicides Controlled by

2,4

- D

Common Lambsquarters Hard

- to

- control (2004)  (2001) 
Common Ragweed Confirmed Resistant (2004)  (1998) 
Eastern Black Nightshade Hard

- to

- control (2004)  (1999) 
Giant Ragweed Confirmed Resistant (2004)  (1998) 
Marestail (horseweed) Confirmed Resistant (2000)  (2000) 

Palmer Amaranth* Confirmed Resistant (2005)  (1991) 
Waterhemp Confirmed Resistant (2005)  (1993) 
Prickly Sida Hard

- to

- control (2004)  (1993) 
* Requires an integrated weed management plan , including additional weed control technology , for acceptable control.
While DAS

- 40278

- 9 corn will enable farmers to better manage glyphosate resistant weeds through use of 2,4

- D and quizalofop herbicides, they will also serve to reduce the selection pressure for resistance to glyphosate and prevent or delay the onset of new cases of resistance. Farmers will be able to apply mixtures of herbicides with t wo or more distinct modes of action. Such mixtures will prevent or severely limit the survival and reproduction of susceptible weeds which are developing resistance to one of the herbicidal modes of action because these weeds will be susceptible to the ot her herbicide(s) in the mixture

. 68 For mixtures to be most effective at delaying resistance, each component alone should be highly efficacious on that weed species. 69 Both 2,4

- D and glyphosate individuallySupplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 39 of 50 Dow AgroSciences LLC provide very high levels of control of important susceptible weed species when applied alone, and show the expected additivity when applied together. This means that when used together, any weed plants that may be developing resistance can be eliminated from the population, curtailing the increase and s pread of the resistance.
As an alternative to mixtures of herbicides, temporally separated spray applications to provide a rotation among modes of action within a growing season can be effective as part of a pre

- emptive resistance management strategy. 68 As with mixtures, a rotation approach to herbicide management is expected to prevent or delay the emergence of new weed management challenges due to resistance. T hrough these practices, the projected trajectory of new glyphosate resistant and hard

- to

- con trol weed issues, such as new resistant biotypes or expanded range of resistant and hard

- to

- control weed populations, can be slowed through the use of 2,4

- D with herbicide tolerant DAS

- 40278

- 9 corn. 4.3 Proposed Use Pattern and Compatibility with Glyphosate Cropping System To encourage a system that incorporates multiple modes of action, Dow AgroSciences has designed the technology to be compatible with the current glyphosate cropping system.
DAS

- 40278

- 9 corn will provide rate and timing flexibil ity to growers to optimize their weed control programs. In contrast to the current use pattern for 2,4

- D on corn which places rate and equipment restriction on the post emergent use in corn , there will be neither crop injury risk nor distinct spray timing and application rate restrictions. DAS

40278

- 9 corn enables a continuous over

- the

- top application window from pre

- planting through the postemergence stage of V8 (vegetative, 8 leaf stage) or 48” tall corn. This application window provides optimal flexib ility for growers to manage their weed control program around cultural operations (including other crops ) or climatic conditions. This window represents the critical weed control period when weed competition has the greatest detrimental effect on corn gro wth. Thus, the use of DAS

- 40278

- 9 corn allows the grower to apply herbicide when weeds are the most sensitive and corn is the most vulnerable to weed competition and thus better control hard

- to

- kill weeds . Additionally, this new application timing comple ments the glyphosate application timings in glyphosate resistant corn. When stacked (combining traits through conventional breeding) with glyphosate tolerance, the combination of 2,4

- D and glyphosate provides

a n exceptional weed control system with maximu m flexibility and efficiency for the grower. Similar to use on conventional corn, a maximum seasonal application rate for 2,4

- D will be 3.0 lbs ae/ac (acid equivalent s /acre)

. While quizalofop is intended to be used as a selection agent to control corn plants without the DAS

- 40278

- 9 trait, in hybrid seed production , grass herbicide concepts can be developed to utilize quizalofop for control of grassy weeds in DAS

- 40278

- 9 corn. This will be the first use of this family of chemistry for gras s weed control in corn. Quizalofop applications would be made up toSupplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 40 of 50 Dow AgroSciences LLC
the V6 (vegetative, 6 leaf) growth stage in corn. Figure 4.1 pictorially details the use pattern for 2,4

- D and quizalofop on DAS

- 40278

- 9 corn and its compatibility with glyphosate applic ations.

* All 2,4

- D application rates are lbs ae/ac , Pre = preemergence , Post = postemergence

The compatibility of the windows for application of all corn herbicides allows growers to easily incorporate DAS

- 40278

- 9 corn into the ir cropping system and increases the ease of delivering multiple modes of action to control weeds and mitigate the development of weed resistance. 4.4 Proactive resistance management for 2,4

- D through integration with glyphosate
Herbicide tolerant DAS

- 4027 8

- 9 corn provides a new tool for managing and delaying glyphosate resistance, managing hard

- to

- control weeds, and preserving the benefits of the herbicide tolerant technologies. However sustainable success with DAS

- 40278

- 9 corn will require long

- term mana gement of resistance to 2,4

- D and quizalofop as well as to glyphosate. A thorough discussion of weed resistance, how it develops, and its management can be found at the Herbicide Resistance Action Committee (HRAC) website. 68
2,4

- D has been used since 1945 with relatively few weed resistance issues. Globally, 16 weed species have documented reports of 2,4

- D resistant biotypes, with only three in the V6 Figure 4.1 2,4

- D, quizalofop, and glyphosate applications schedules for DAS

40278

- 9 Corn*

Pre 1 lb/A Post 0.5

- 1 lb/A

(up to 2 applications)
min of 12 days apart) V8

or
48” Glyphosate Pre

- emergence Glyphosate

Post

- emergence Glyphosate Pre

- Harvest
Quiz post up to 0.082 lb/ASupplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 41 of 50 Dow AgroSciences LLC continental United States (wild carrot, field bindweed, prickly lettuce). 70 No ne of these

are of substantial economic importance and none has shown a large degree of spread from their point of origin. The rarity of resistance to 2,4

- D or other auxinic herbicides has been attributed to: 71 , 72 , 73 , 74 , 75

 multiple sites of action for these auxin herbicides in the plant,

 redundancy in receptors and other components of the auxin signal response,

 frequent use in mixtures with other herbicides,

 a fitness penalty associated with auxin resistance mechanisms in weeds, and

 quantitative inheritance of the trait

 short soil half

- life (residual)

The fop ( aryloxyphenoxypropionate ) herbicides and other ACC

- ase inhibitor herbicides have been used widely to control grass weed species since their introduction in the 1970’s and 1980’s. Today there are 15 weed species in the United States with documented resistance to one or more ACC

- as e inhibitor herbicides. 70 In the United States, there are

no known instances of multiple

- resistance to both glyphosate and ACC

- ase inhibitors. 70
The same principles of weed resistance management discussed above for glyphosate apply directly to 2,4

- D and t he fop herbicides. Unlike past experience with glyphosate, farmers will be encouraged to use multiple herbicide modes of action with DAS

- 40278

- 9 corn to control their weed problems. From commercial launch, DAS

- 40278

- 9 will be stacked with glyphosate resi stant corn so that farmers may be able to select among 2,4

- D, glyphosate, and a mixture of the two for their postemergence broadleaf weed control. Farmers will have multiple options to control grass weeds in Dow AgroSciences’ herbicide tolerant corn , incl uding soil applied grass herbicides , postemergence applications of glyphosate, or postemergence applications of quizalofop herbicide. Selection pressure for 2,4

- D or fop

- resistant weed biotypes will be mitigated by the ability to also use glyphosate concu rrently. Since glyphosate still effectively controls most grass and broadleaf weed species , use of glyphosate will prevent or delay selection for 2,4

- D resistance. Formal herbicide stewardship programs being developed for use with DAS

- 40278

- 9 corn will pr ovide farmers with the knowledge and tools to optimally manage resistance to 2,4

- D and glyphosate, to ensure the enormous benefits of herbicide

- tolerant cropping systems can be continued for the long term. Dow AgroSciences’ stewardship program will includ e substantial grower education on cost

- effective integrated weed management. An extensive network of sales representatives, field scientists, and agronomists will play an important role in educating and training applicators and growers on the proper use o f the technology. Dow AgroSciences field personnel will work with growers to select the seed and herbicide products appropriate to their needs.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 42 of 50 Dow AgroSciences LLC Dow AgroSciences will recommend a program approach for broad

- spectrum weed control. Pre

- plant and preemergence herbicides will be recommended to provide early season control of a range of broadleaf and grass herbicides. For example, SureStart ® (a premix of acetochlor, flumetsulam, and clopyralid) is a residual herbicide that provides a broad

- spectrum foundation c ontrol of grasses and broadleaf weeds and can be applied in corn from pre

- plant to early postemergence . These herbicide programs provide additional modes of action to 2,4

- D, quizalofop, and glyphosate and they control several weeds that are increasingly p roblematic in g lyphosate tolerant crop s, such as horseweed (marestail), waterhemp, common lambsquarters, velvetleaf, common and giant ragweed, pigweed, morning glory, kochia, and Palmer amaranth. Dow AgroSciences is voluntarily adopting mode of action labe ling for its herbicides that can be used with DAS

- 40278

- 9 corn, following the WSSA mode of action classification. These labels will include clear weed resistance management language promoting agronomic practices that reduce the likelihood that resistant w eed populations will develop and can be used to manage weed resistance if it occurs. These recommendations will be product specific, but generally include the use of appropriate herbicide mixtures, rotation of herbicides from different mode of action grou ps, use of burndown and residual applications of herbicides at or prior to planting, use of full labeled rates of glyphosate, 2,4

- D and quizalofop when applied, use of alternative weed control practices such as delayed planting and use of weed

- free crop se eds, and scouting of fields after applications for any weeds that may have escaped treatment or show evidence of less

- than

- expected control. Growers will also be asked to report to Dow AgroSciences any incidents of repeated non

- performance of these herbici des with DAS

- 40278

- 9 corn. In addition to labeling on Dow AgroSciences herbicides, weed resistance management practices will be recommended in documentation that accompanies the DAS

- 40278

- 9 seed. As with Dow AgroSciences’ other genetically engineered see d products (Herculex ® family of insect protection in corn, WideStrike ® insect protection in cotton, and REFUGE ADVANCEDTM powered by SmartStax ® in corn) D growers who purchase and plant corn hybrids containing DAS

- 40278

- 9 will be required to have a signed G rower Agreement in place. The Grower Agreement is a legal and contractual obligation that includes a provision requiring them to follow the relevant Product Use Guide. Product Use Guides are being developed and will be provided to all growers using the t echnology. These Guides will describe appropriate trait stewardship guidelines

D SmartStax ® multi

- event technology developed by Dow AgroSciences and Monsanto.

TM REFUGE ADVANCED is a trademark of Dow AgroSciences LLC. ® SmartStax is a registered trademark of Monsanto Technology LLC. ®TM HERCULEX and the HERCULEX Shield Logo are regist ered trademarks of Dow AgroSciences LLC REFUGE ADVANCED is not registered for sale or use in all states.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 43 of 50 Dow AgroSciences LLC including effective weed resistance management based around sound agronomic practices and integrated approaches to weed control. The diversity of herbicide modes of action that can be applied to DAS

- 40278

- 9 corn, coupled with cultural approaches to weed management, are expected to provide robust resistance management and insure long term viability of each of the components. Therefore Dow AgroSciences’ DAS

- 40278

- 9 herbicide tolerant corn will promote the sustainable use and considerable benefits of herbicide tolerant crops.

5 Economic Benefits of Dow AgroSciences H erbicide T olerant T echnology The introduction of glyphosate tolerant soybeans and corn enabled adoption of

conse rvation tillage practices because weeds could be successfully controlled without additional tillage. Over the last few years, weed resistance to glyphosate has developed and continues to spread. Some weeds can be controlled with other herbicides at an ad ditional cost. In some situations, farmers have reverted back from no

- till systems to conventional tillage or minimum tillage systems in order to control weeds such as marestail, giant ragweed and Palmer amaranth incurring not only the cost of additional tillage but also losing the positive environmental benefits associated with reduced tillage.
A study was conducted to evaluate the economic impacts of glyphosate resistant weeds and herbicide tolerant DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soybean at the farm l evel through individual case study analysis and to determine the aggregate economic effects at the national level using the IHS partial equilibrium models for US crops and farm income. The study is presented in Appendix A. Both the case study analysis an d national analysis utilized scenario analysis to contrast a baseline situation of no weed resistance with situations of weed resistance without DAS

- 40278

- 9 and DAS

- 68416

- 4 technology and weed resistance with DAS

- 40278

- 9 and DAS

- 68416

- 4 technology. Glyphos ate resistant weed infestations significantly reduce farm income, erode net worth, and have significant environmental consequences from tillage changes. The corn case studies which did not include tillage impacts for any of the cases show that farmers cou ld reduce their farm income impacts from glyphosate resistant weeds by 16 to 19 percent with DAS

- 40278

- 9 technology.
Similar to the case studies, on a national basis herbicide tolerant DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soybean were found in the study to offset over 18 percent of the net farm income impacts and eliminate environment impacts saving the equivalent of emissions from over 19,000 cars per year and reducing soil erosion by 2.6 million tons per year in the United States. Over the 2011 to 2020 pe riod, with DAS herbicide tolerantSupplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 44 of 50 Dow AgroSciences LLC technology, growers would save $4 billion in net farm income and consumers would save $563 million.

6 Impact of 2,4

- D on Herbicide Tolerant DAS

- 40278

- 9 Corn and DAS

- 68416

- 4 Soybeans on the Cost and Environmental Load of H erbicides Applied on Glyphosate Tolerant Corn and Soybeans to Control Glyphosate Resistant and Glyphosate Tolerant Weed Biotypes An analysis was conducted to determine the impact of the use of 2,4

- D on herbicide tolerant DAS

- 40278

- 9 corn and DAS

- 68416

- 4 soybeans on the environmental load of herbicides applied on glyphosate tolerant corn and soybeans to control glyphosate resistant a nd hard

- to

- control weed biotypes. Third party prop r ietary data for corn and soybeans and a survey of university weed specialists were used to create assumptions for how growers would change herbicide use on glyphosate tolerant corn and soybeans to manage glyphosate resistant and hard

- to

- control weed biotypes. The full analysis is presented in Appendix B and the university weed specialist survey is presented in Appendix C. Analyses were completed for corn in five states and for soybeans in five states targeting control of a glyphosate resistant weed species that are present in each state The analysis indicated that the use of 2,4

- D on herbicide tolerant DAS

- 40278

- 9 corn for control of glyphosate resistant and hard

- to

- control weed biotypes would reduce t he per acre environmental load of herbicides applied on glyphosate tolerant corn by 0. 15 to 0.74 lb ai/ac, with an overall average reduction of 0. 49 lb ai/ac across all scenarios, compared to the use of currently registered alternative non

- glyphosate herbi cides. Application rates of some non

- glyphosate alternative herbicides in corn have low rates (examples: isoxaflutole, mesotrione, topramezone), however, the pervasive use of acetamide and triazine herbicides increases the herbicide environmental load i n corn.
Conclusions Herbicide tolerant crops have played, and continue to play, a central role in improving U.S. agricultural productivity and protecting the agricultural environment. Herbicide tolerant crops have enabled the widespread adoption of conser vation tillage practices that preserve soil health, can improve water quality, and improve efficiency of utilization of agricultural inputs, while improving weed management and increasing farm income. U.S. farmers have enjoyed the benefits of an easy

- to

- u se, flexible, and cost

- effective weed management technology based around glyphosate. This success has resulted in a recent rise in glyphosate resistant weeds and hard

- to

- control weeds as a consequence of

over

- reliance on a single herbicide mode of action. Alternatives to the glyphosate systemSupplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 45 of 50 Dow AgroSciences LLC that share the same benefits but enable use of alternative modes of action are necessary to preserve the benefits of herbicide tolera nt crops for the long

- term. Dow AgroSciences has developed an alternative herbicide tolerant technology for corn using the aryloxyalkanoate dioxygenase herbicide tolerance gene. Dow AgroSciences’ herbicide tolerant DAS

- 40278

- 9 corn provides an important alternative to glyphosate

only herbicide tolerance and is a powerful tool that can h elp solve the challenges of weeds that are resistant to, or hard to control with, glyphosate. By enabling the use of 2,4

- D and quizalofop herbicides in addition to glyphosate, DAS

- 40278

- 9 corn will allow the use of one more tool to control glyphosate resi stance. In addition, Dow AgroSciences’ herbicide tolerant trait will enable easy implementation of effective weed resistance management programs based on pre

- mixes, tank mixes, and/or herbicide rotation programs that use multiple modes of action to contro l weed populations. Specific stewardship programs to be implemented alongside DAS

- 40278

- 9 corn will help to preserve glyphosate efficacy and promote 2,4

- D weed resistance management. By offering a simple, effective, and flexible alternative to glyphosate

- only herbicide tolera nt crops , Dow AgroSciences’ herbicide tolerant DAS

- 40278

- 9 corn will create the opportunity to preserve and extend the many environmental and economic benefits farmers have realized from using g lyphosate tolerant crop s and provide U.S. farmers with a cutting edge technology to enhance global competitiveness.

1 USDA National Agricultural Statistics Service (NASS) acreage report, annual issues 2000

– 2009.

2 Third Party Proprietary Data, 2009

3 Supplemental Toolkit For Investors. Monsanto. February 2010.

4 Fernandez

- Cornejo J. and McBride, W. (2002). Adoption of bio

- engineered crops, USDA, ERS Agricultural Economics Report No 810.

5 Duke, S. O., & Powles, S. B. Mini

- review Glyphosate: a once in a century herbicide. Pest Management Science, 64, 319

- 325. 2008.

6 Lin, W., Price, G. K., & Fernandez

- Cornejo, J. (2001). Estimating Farm Level Effects of Adopting Herbicide

- Tolerant Soybeans. USDA, Economic Research Service. Economic Research Service/U SDA.

7 Gianessi LP, Economic and herbicide use impacts of glyphosate

- resistant crops. Pest Management Science 61:241

- 245. 2005.

8 Gianessi LP, Economic impacts of glyphosate

- resistant crops. Pest Management Science 64:346

- 352. 2008.

9 Duke, S. O., & Po wles, S. B. Glyphosate

- Resistant Crops and Weeds: Now and in the Future. AgBioForum, 12 (3&4), 346

- 357. 2009.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 46 of 50 Dow AgroSciences LLC

10 Marra, M. C., Piggott, N. E., & Carlson, G. A. (2004). The Net Benefits , Including Convenience, of Roundup Ready Soybeans: Results from a National Survey. National Science Foundation. Raleigh: NSF center for IPM.

11 Piggott, N. E., & Marra, M. C. (2008). Biotechnology Adoption Over Time in the Presence of Non

- Pecuniary Charact eristics that Directly Affect Utility: A Derived Demand Approach. AgBioForum, 11 (1), 58

- 70.

12 Grilliches, Z. Hybrid Corn: An Exploration into the Economics of Technical Change. Econometrica. 2:501

- 525. 1957.

13 Rogers, E.M. Diffussion of Innovation. Thir d edition, The Free Press, New York. 1983.

14 Wozniak, D. The Adoption of Interrelated Innovations: A Human Capital Approach. The Review of Economics and Statistics. Vol. 66, Issue 1(February):70

- 79. 1984.

15 Caswell, M., and D. Zilberman. The Choice of I rrigation Technologies in California. American Journal of Agricultural Economics. 67(May):224

- 34. 1985.

16 McNamara, K.T., M.E. Wetzstein, and G.K. Douce. 1991. Factors Affecting Peanut Producer Adoption of Integrated Pest Management. Review of Agricultura l Economics. 13(January):129

- 39.

17 Marra, M., B.J. Hubbell, and G. Carlson. 2001. Information Quality, Technology Depreciation, and Bt Cotton Adoption in the Southeast. Journal of Agricultural and Resource Economics. 26(1):158

- 175.

18 Ervin, D. E. et.al. Im pact of Genetically Engineered Crops on Farm Sustainability in the United States. Committee on the Impact of Biotechnology on Farm

- Level Economics and Sustainability. National Research Council. Prepublication Copy. ISBN: 0

- 309

- 14709

- 3. 2010.

19 Fawcett, R., and D. Towery “Conservation tillage and plant biotechnology: How new technologies can improve the environment by reducing the need to plow,” Conservation Technology Information Center (CTIC), West Lafayette, IA. 2002.

20 Frisvold, G. B., Boor, A., & Ree ves, J. M. (2009). Simultaneous Diffusion of Herbicide Resistant Cotton and Conservation Tillage. AgBioForum, 12 (3&4), 249

- 257.

21 Locke, M. A., Zablotowicz, R. M., & Reddy, K. N. (2008). Integrating soil conservation practices and glyphosate

- resistant cro ps: impacts on soil. Pest Management Science, 64, 457

- 469.

22 Trigo, E.J., and Cap, E.J. (2006). “ Ten Years of Genetically Modified Crops in Argentine Agriculture,” Research Report, Argentine Council for Information and Development of Biotechnology

– ArgenB io.

23 American Soybean Association. Conservation Tillage Study. Saint Louis, MO. Available at http://www.soygrowers.com/ctstudy/ctstudy_files/frame.htm. 2001

. 24 Dill, G.M. Ca Jacob, C.A., & Padgette, S.R. Glyphosate

- resistant crops: adoption, use and future considerations. Pest Management Science, 64(4), 326

- 331. 2008.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 47 of 50 Dow AgroSciences LLC

25 Cerdeira, A. L., & Duke, S. O. The Current Status and Environmental Impacts of Glyphosate

- Resistant Crops: A Review. Journal of Environmental Quality, 35, 1633

- 1658. 2006.

26 Mueller, T. C., Mitchell, P. D., Young, B. G., & Culpepper, A. S. Proactive versus reactive management of glyphosate

- resistant or

- tolerant weeds. Weed Technology, 19, 924

- 933. 2005.

27 Webs ter, T. M., & Sosnoskie, L. M. (2010). Loss of Glyphosate Efficacy: A Changing Weed Spectrum in Georgia Cotton. Weed Science, 58, 73

- 79.

28 Konduru, S., Kruse, J., & Kalaitzandonakes. The Global Economic Impacts of Roundup Ready Soybeans. Genetics and Genom ics of Soybean. Chapter 19. Edited by G. Stacey. Springer 2008.

29 Brookes, G., & Barfoot, P. Gm Crops: The Global Economic and Environmental Impact

- The First Nine Years 1996

- 2004. AgBioForum, 8 (2&3), 187

- 196. 2005.

30 Brookes, G., & Barfoot, P. (2008). Global impacts of Biotech Crops: Socio

- Economic and Environmental Effects, 1996

- 2006. AgBioForum, 11 (1), 21

- 38.

31 Sankula, Sujatha., and Blumenthal, E. Impacts on U.S. agriculture of biotechnology

derived crops planted in 2003: An update of eleven case studies . Washington, DC: National Center for Food and Agriculture Policy. 2004. Available on the World Wide Web: http://www.ncfap.org/whatwedo/pdf/2004finalreport.pdf

. 32 Sankula, Sujatha “ Quantification of the Impacts on U.S. Agriculture of Biotechnology

Derived Crops Planted in 2005,” Report by National Center for Food and Agricultural Policy, Washington DC. 2006.

33 USDA

- NRCS (U.S. Department of Agriculture

– Natural Resources Conservati on Service). Energy Consumption Awareness Tool: Tillage. Washington, DC: U.S. Department of Agriculture

– Natural Resources Conservation Service, Available online at http://ecat.sc.egov.usda.gov/ . Accessed M ay 4, 2010.

34 Mitchell, J.P., D.S. Munk, B. Prys, K.M. Klonsky, J.F. Wroble, and R.L.D. Moura. Conservation tillage production systems compared in the San Joaquin Valley cotton. California Agriculture 60(3): 140

- 145.

35 Sanders, L.D. The economics of con servation and conservation tillage. Paper presented at the International Symposium on Conservation Tillage. 2000. Available via the web at: http://agecon.okstate.edu/isct/labran za/sanders/mazecon00.doc

. 36 Jasa, P.J. Conservation tillage systems. Paper presented at the International Symposium on Conservation Tillage. Mazatlan, Mexico. 2000. Available online at http://agecon.okstate.edu/isct/labranza/jasa/tillagesys.doc.

37 Ferna ndez

- Cornejo, J., and J. Li. The impacts of adopting genetically engineered crops in the USA: The case of Bt corn. Paper presented at the American Agricultural Economics Association Annual Meeting in Providence, RI. 2005. Available online at http://age consearch.umn.edu/bitstream/19318/1/sp05fe01.pdf.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 48 of 50 Dow AgroSciences LLC

38 Fernandez

- Cornejo, J., and A.K. Mishra. Off

- farm income, production decisions, and farm economic performances. ERR #36. U.S. Departmen of Agriculture

– Economic Research Service. Washington D.C. 2007. Available online at http://hdl.handle.net/10113/20582

. 39 Gardner, J.G., and C.H. Nelson. Genetically modified crops and labor savings in U.S. crop production. Paper presented at the Southern Agricultural Eco nomics Association Annual Meeting in Mobile, AL. University of Illinois at Urbana

- Champaign. 2007.

40 F alck

– Zepeda, Jose B., G. Traxler, R.G. Nelson “Rent Creation and Distribution From Biotechnology Innovations: The Case of Bt Cotton and Herbicide

- Toler ant Soybeans in 1997,” Agribusiness, Vol. 16, 1, 21

– 32. 2000.

41 Moschini, Giancarlo, H. Lapan, and A. Sobolevsky “ Roundup Ready Soybeans and Welfare Effects in the Soybean Complex,” Agribusiness , 16 (1): 33

- 55. 2000.

42 Qaim, Matin, and G. Traxler (2002). “Roundup Ready Soybeans in Argentina: Farm Level, Environmental, and Welfare Effects,” 6 th International ICABR Conference, Ravello, Italy, July 11

- 14

43 Trigo, E.J., and Cap, E.J. (2006). “ Ten Years of Genetically Modified Crops in Argentine Agriculture,” Research Report, Argentine Council for Information and Development of Biotechnology

– ArgenBio.

44 Benbrook, Charles (1999). “Evidence of the magnitude and consequences of the Roundup Ready Soybean Yield Drag from University

- Based Variety Tests in 1998, Ag BioTech Info Net Technical Paper 1, www.biotech

- info.net/RR_yield_drag_98.pdf

45 Duffy, Michael, and M. Ernst. (1999). Does Planting GMO Seed Boost Farmers'Profits? Iowa State University, Leopol d Center for Sustainable Agriculture, Leopold Letter, Vol. 11, No. 3.

46 Elmore, R.W., Roeth, F.W., Nelson, L. A., Shapiro, C. A., Klein, R. N., Knezevic, S. Z.,Martin, A. “Glyphosate

- Resistant Soybean Cultivar Yields Compared with Sister Lines,” Agronomy J ournal, 93: 408

– 412. 2001.

47 Oplinger, E.S., M. J. Martinka, J. M. Gaska, K. A. Schmitz and C. R. Grau. Wisconsin soybean variety test results, A3654, Department of Agronomy and Plant Pathology, University of Wisconsin

- Madison, 1998. http://www.uwex.edu/c es/soybean/research/98soyvar/98soyvar.pdf.

48 Marra, M., Pardey, P., & Alston, J. (2002). The payoffs to transgenic field crops: an assessment of the evidence. AgBioForum, 5(2), 43

– 50.

49 Gianessi, L.P., and J. E. Carpenter (2000). “Agricultural Biotechnolog y: Benefits of Transgenic Soybeans,” A Report by National Center for Food and Agricultural Policy, Washington DC.

50 Carpenter, J. C. Peer

- reviewed surveys indicate positive impact of commercialized GM crops. Nature Biotechnology, 28 (4), 319

- 321. 2010.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 49 of 50 Dow AgroSciences LLC

51 Bertram, M. G., & Pedersen, P. (2004). Soybean: Adjusting Management Practices Using Glyphosate

- Resistant Soybean Cultivars. Agronomy Journal, 96, 462

- 468.

52 Frisvold, G. B., Hurley, T. M., & Mitchell, P. D. (2009). Overview: Herbicide Resistant Crops

- Di ffusion, Benefits, Pricing, and Resistance Management. AgBioForum, 12 (3 & 4), 244

- 248.

53 Boerboom C.M. 2007. The stewardship continuum. 32

– 36 in Boerboom C.M., Owen M.D.K. National Glyphosate Stewardship Forum II: A Call to Action . St. Louis, MO: North Central IPM Center. http://www.weeds.iastate.edu/mgmt/2007/NGSFII_final.pdf

. Accessed: April 28, 2010.

54 Culpepper A.S. 2006. Glyphosate

- induced weed shifts. Weed Technol . 20: 277

– 281.

55 Heap, I. 2010. The international survey of herbicide resistant weeds. from WeedScience.org, http://www.weedscience.org/. Accessed March 31, 2010.

56 Third Party Proprietary Data, 2009.

57 Ervin, D.E. et.al. Impact of Genetically Engineered Crops on Farm Sus tainability in the United States. Committee on the Impact of Biotechnology on Farm

- Level Economics and Sustainability. National Research Council. Prepublication Copy. ISBN: 0

- 309

- 14709

- 3. 2010.

58 VanGessel, M.J. 2001. Glyphosate

- resistant horseweed from Delaware. Weed Science 49:703

– 705.

59 Givens, W. A. 2010. Shifts in Herbicide Use, Tillage Practices, and Perceptions of Glyphosate

- resistant Weeds Following Adoption of Glyphosate

- resis tant Crops. Miss. State Univ. Dissertation. http://sun.library.msstate.edu/ETD

- db/theses/available/etd

03312010

- 103616/

. Accessed: April 28, 2010.

60 Owen, MDK. 2008. Weed species shifts in glyphosate

- resistant crops. Pest Management Science 64(4):377

- 387.

61 Vindrine, P.R., J.L. Griffin and D.C. Blouin. 2002. Evaluation of reduced rates of glyphosate and chlorimuron in glyphosate

- resistant soybean (Gl ycine max). Weed Technology 16:731

- 736.

62 Golden Harvest. 2007. Weed management strategies for herbicide tolerant corn. http://www.ghcommunications.com/Upl oads/Agronomy_Studies/HerbicideTolerantCorn. pdf . Accessed May 5, 2011.

63 Third party proprietary data

. 64 Herbicide Resistance Action Committee. http://www.hracglobal.com/Publications/HRACManagementandWeedResistance/tabid/2 28/Default.aspx . Accessed April 28, 2010.
65 Weed Resistance Management Guidelines. http://www.weedresistan cemanagement.com/guidelines.html . Accessed April 28, 2010.Supplemental Information for USDA Petition for Nonregulated Status of DAS

- 40278

- 9 Corn Page 50 of 50 Dow AgroSciences LLC

66 Moomaw, R.S. and F.W. Roeth. 1977. Differential tolerance of corn hybrids to 2,4

- D. North Cent. Weed Cont. Conf. Proc. 32:79.

67 HRAC. Classification of Herbicides According to Site of Action

. http://www.hracglobal.com/Publications/ClassificationofHerbicideSiteofAction/tabid/222 /Default.aspx . Accessed May 5 , 2011.

68 HRAC. Guidel ines to the Management of Herbicide Resistance. http://www.hracglobal.com/Publications/ManagementofHerbicideResistance/tabid/225/D efault.aspx . Acc essed May 5, 2011.
69 Neve, P. 2008. Simulation modeling to understand the evolution and management of glyphosate resistance in weeds. Pest Management Science 64 :392

– 401
70 Heap, I. 2009. The International Survey of Herbicide Resistant Weeds. http://www.weedscience.com
71 Jasieniuk, M., Brule

- Babel, A.L. and Morrison, I.N. 1996. The evolution and genetics of herbicide resistance in weeds. Weed Science 44:176

- 193.
72 Walsh, T.A., Neal, R., Merlo, A.O., Honma , M., Hicks, G.R., Wolff, K., Matsumura, W. and Davies, J.P. 2006. Mutations in an auxin receptor homolog AFB5 and in SGT1b confer resistance to synthetic picolinate auxins and not to 2,4

- Dichlorophenoxyacetic acid or indole

- 3

- acetic acid in Arabidopsis. Plant Physiology 142:542

- 552.
73 Kern, A.J., Chaverra, M.E. and Dyer, W.E. 2005. Dicamba

- responsive genes in herbicide

- resistant and susceptible bioytpes of kochia ( Kochia scoparia ). Weed Science 53:139

- 145.
74 Bourdot, G.W., Saville, D.J., and Hurrell, G.A. 1996. Ecological fitness and the decline of resistance to the herbicide MCPA in a population of Ranunculus acris . Journal of Applied Ecology 33:151

- 160.
75 Cranston, H.J., Kern, A.J., Hackett, J.L., Miller, E.K., Maxwell, B.D., and Dyer, W.E. 2001 . Dicamba resistance in kochia. Weed Science 49:164

- 170.