Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 1 of 53 

### Supplemental Information to Support the NEPA Analysis for the Determination of Nonregulated Status of Dicamba-Tol erant Soybean MON 87708 and Dicamba- and Glufosinate-Tolerant Cotton MON 88701

Impact and Benefits of Dicam ba-Tolerant Soybean and Dicamba and Glufosinate-Tolerant Cotton on Weed Resistance Management

OECD Unique Identifiers: MON-877Ø 8-9 (soybean) and MON-887Ø1-3 (cotton) Monsanto Petition Numbers: 10-SY-210U (s oybean) and 12-CT-244U/ 12- CT-244U-S (cotton) USDA Petition Numbers: 10-188-01p (soybean) and 12-185-01p_a1 (cotton)

January 17, 2014

Submitted by:

Rhonda M. Mannion, B.S.

Monsanto Company 800 North Lindbergh Blvd. St. Louis, MO 63167 Phone: (314) 694-8785

Fax: (314) 694-3080 E-mail: rhonda.m.mannion@monsanto.com



### Prepared by: J.K. Soteres, Ph.D. and R.M. Mannion, B.S.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 3 of 53 

### Table of Contents

Introduction and Background

......................................................................................................... 4

Background

– Legal

............................................................................................................................... .... 5

Background

– Herbicide Use

..................................................................................................................... 6



### Benefits of DT Soybean and DGT Cotton for Weed Control and Resistance Management

......... 10

Dicamba Resistance: Potential

..................................................................................................... 12

Impact of Dicamba Resistance

...................................................................................................... 13

Results and Discussion

.................................................................................................................. 14

Current Dicamba Uses and Identification of Highest Risk Areas

.................................................. 14

Dicamba Weed Targets

........................................................................................................................... 16

Weed Management Systems for Current Dicamba Uses

....................................................................... 17

Herbicide Options to Control Weeds in Current Dicamba Crop Uses

.................................................... 17

Scope and Impact of Existing Dicamba Resistant Species

...................................................................... 18

Weed Resistance Management Stewardship

......................................................................................... 19



### Conclusions

............................................................................................................................... .... 19

Appendix A

............................................................................................................................... ..... 41

Appendix B

............................................................................................................................... ..... 44

References

............................................................................................................................... ..... 49Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 4 of 53 

## Introduction and Background

Monsanto has developed a new biotechnology-derived soybean ( Glycine max ), designated as event MON 87708 (“DT soybean”), that is tolerant to dicamba herbicide, and a new biotechnology-derived cotton ( Gossypium spp

. ), designated as event MON 88701 (“DGT cotton”), that is tolerant to di camba and glufosin ate herbicides. Monsanto submitted petitions for determinations of nonregulated status for DT soybean and DGT cotton three and one years ago, respectively, and has provided th e U.S. Department of Agricultu re (USDA) Animal and Plant Health Inspection Service (APHIS) with leng thy scientific materials and Environmental Reports. 1,2 

### This document addresses the impact and benefits of DT soybean and DGT cotton on weed resistance management. As discussed herein, the approval of DT soybean and DGT cotton, will provide growers with an important new tool to manage weeds and mitigate the

further evolution of resistance to some current U.S. herbicides.

Associated with the cultivation of DT soybean and DGT cotton will be an increase in use of dicamba, which will potentially result in increased se lection pressure for resi stant biotypes. This risk can be significantly mitigated by incorpora ting dicamba into a diversified weed management program. To evaluate this risk Monsanto has conducted an analysis to understand the risk of cross-over resistance (i.e., resistance that may e volve in soybean or cotton and then impact other dicamba crop uses) by evaluating: (1) the primar y weed targets and the current extent of dependence on dicamba for weed management, and (2) the potential overlap of weed species across these cropping systems. Overa ll, the analysis indica tes that risk of cross-over resistance is low, and because of the low dependency of farm ers on dicamba for weed management in these

areas combined with th e availability of other herbicide options, the potenti al socio-economic impact of cross-over resistance would be low.

1 Petition for the Determination of Nonregulated Status for Di camba-Tolerant Soybean MON 87708, Monsanto Petition Number:

10-SY-201U (July 6, 2010) ; Supplemental Info rmation to Support the NEPA Analysis for the Determination of Nonregulated Status of Dicamba-Tolerant Soybean MON 87708, Petition # 10-188-01p (Oct. 11, 2012); Supplemental Information to Support the NEPA Analysis for the Determ ination of Nonregulated Status of Di camba-Tolerant Soybean MON 87708, Petition # 10-188-01p (Dec. 14, 2012); Supplemental Information to S upport the NEPA Analysis for the Determination of Nonregulated Status of Dicamba-Tolerant Soybean MON 87708, Petition # 10-188-01p (Jan. 31, 2013); Petitioner’s Environmental Report for Dicamba-Tolerant Soybean MON 87708 and Dicamba- and Glufosinate-Tolerant Cotton MON 88701, Monsanto Petition Numbers 10-188-01p and 12-185-01p_al) (Nov. 25, 2013).

2 Petition for the Determination of Nonregulated Status for Dicamba and Glufosinate-Tolerant Cotton MON 88701, Monsanto

Petition Number: 12-CT-244U (July 2, 2012); Petitioner’s Envi ronmental Report for Dicamba and Glufosinate-Tolerant Cotton MON 88701, Monsanto Petition Number: 12-CT- 244U-S (USDA Petition #12-185-01p_al) (May 6, 2013); Petitioner’s Environmental Report for Dicamba-Tolerant Soyb ean MON 87708 and Dicamba- and Glufosinate-Tolerant Cotton MON 88701, Monsanto Petition Numbers 10-188-01p and 12-185-01p_al) (Nov. 25, 2013).Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 5 of 53 Background

– Legal



### On May 16, 2013, APHIS announced its intention to prepare a full Environmental Impact Statement (EIS) not only to address jurisdictiona l plant pest issu es under the Plant Protection Act (PPA), but also to examine the possible envi ronmental impacts of di camba herbicide uses, including the potential fo r development of herb icide-resistant weeds. 3 

### As discussed in previous submissions to APHIS, Monsanto does not believe that addressing the impacts of herbicide uses in an EIS, as described by AP HIS’s May 16, 2013 Notice of Inte nt (NOI), is required by the National Environmental Policy Act (NEPA) or any other law.

First, the PPA does not give APHI S regulatory authority over herb icide uses or impacts, or to address herbicide resistance. Indeed, Congress expressly transferred re gulatory authority over herbicides from APHIS to EPA over four decades ago 4 

### , and APHIS itself has long recognized the strict limits on its PPA authority. 5 

### On the other hand, EPA’s authority to regulate herbicides

under FIFRA includes an evaluation of, and measures to address, the development of herbicide resistance in weeds associated with the use of those products. 6 

### Accordingly, APHIS has no jurisdiction over herbicides or th e development of herbicide resi stance in weeds that may be associated with herbicide use, and no authority to consider herbicide impacts under the PPA. Consequently, APHIS has no obligation under NEPA to consider herbicide resistance in weeds (or any other environmental impacts of dicamba or gl ufosinate use, or to consider alternatives to deregulation based on these factors) as “effects” since there is no reas onable alternative to deregulation once APHIS finds DT soybean and DGT cotton do not pose a greater plant pest risk than their conventional counterparts. 7 

### As discussed in previous documentation submitted to APHIS, this longstanding understanding of NEPA was recently confirmed by the U.S. Court of Appeals for the Ninth Circuit. 8



### It is likewise inappropriate for APHIS to id entify weed resistance as a “cumulative impact” under 40 C.F.R. §1508.7. As discussed above, any deci sions regarding restric tions of the use of

3 78 Fed. Reg. 28796.

4 Ruckelshaus v. Monsanto Co. , 467 U.S. 986, 991(1984) (observing that “t he Department of Agriculture’s FIFRA

responsibilities were transferred to the then ne wly created Environmental Protection Agency....”); see also Pub.L. No. 92-516, 86 Stat. 973 (1972).

5 See Center for Food Safety v. Vilsack, 718 F.3d 829, 840 (9th Cir. 2013).

6 See, e.g., EPA, Pesticide Registration (PR) Notice 2001-5, “Guidance for Pesticide Registrants on Pesticide

Resistance Management Labeling,” p. 2 (2001), available at http://www.epa.gov/PR_Notices/pr2001-5.pdf (labeling measures to assist in pesticide resistance manage ment). Additionally, pesticide registrants must report resistance to EPA as an adverse effect in order to ensure the pesticide continues to meet FIFRA requirements for registration. 40 C.F.R. § 159.188(c).

7 DOT v. Public Citizen , 541 U.S. 752, 770, 769 (2004) (where an ag ency has no ability to prevent a certain effect

due to its limited statutory authority over the relevant actions, the agency cannot be considered a legally relevant “cause” of the effect, and is therefore not required to an alyze the environmental impact of an action it could not refuse to perform).

8 For further discussion of the litigation, see Section I.B.4 of Petitioner’s Environmental Report for DicambaTolerant Soybean MON 87708 and Dicamba- and Glufosinate-Tolerant Cotton MON 88701, Nov. 25, 2013.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 6 of 53 

### dicamba (including any such measur es related to weed resistance) are within the sole purview of EPA; APHIS has no control whatsoev er over the nature of any such restrictions. Lacking such control, APHIS is not required to address the EPA decision on di camba, or the consequences of such decision, as cumulative impacts. 9 

### In short, any weed resist ance impacts associated with herbicide uses are not caused by APHIS’s PPA determinations, and cannot trigger a need to perform NEPA review in connectio n with a PPA determination. And, of course, weed resistance and any responses thereto, cannot constitute signif icant environmental impacts of an APHIS PPA determination. Indeed, multiple federal courts have held that EPA’s review under FIFRA is the “functional equivalent” of NEPA. 10 

### Thus, APHIS’s review of re sistance issues would duplicate the NEPA-equivalent analyses already being performed by EPA under its authorities.

If APHIS intends nevertheless to include such materi al in its EIS, it should make clear that it is exercising its discretion to perform that analysis in the document, not that it is legally required to

include that material under NEPA or any other statute.

Background

– Herbicide Use



### In the decades since the introduction of the first herbicide (2,4-D) for weed control in corn in early 1940s, herbicide use has become a critical agronomic tool that is used on the vast majority of cropland in the United States. By 1962, farmers had access to approximately 100 herbicides available in approximately 6000 formulations. According to a 2006 study, farmers routinely use

herbicides on more than 90% of the area of most crops grown in the U.S. (Gianessi and Reigner 2006).

Weed control in crop production is essential for optimizing yields because weeds compete with crops for light, nutrients, and soil moisture. Weed s can also harbor insects and diseases, and can interfere with harvest, causing extra wear on harvest equipment. A study by CropLife America demonstrated that in 2005 the use of herbicides saved U.S. farmers 337 million gallons of fuel, produced $16 billion in crop yield increases, and cut weed control costs by $10 billion as compared to production without the use of herbicides (Gianessi and Reigner 2006). Additionally, without herbicides growers would have to aba ndon no-till and other conservation tillage production practices, which reduce soil erosion. If U.S. growers stopped using herbicides and resumed tillage on the number of acres not tilled in 2005, an additional 356 billion pounds of

9 DOT v. Public Citizen , 541 U.S. 753, 767 (2004).

10 Envtl. Def. Fund, Inc. v EPA , 489 F.2d 1247, 1256 (D.C. Cir. 1973) (holding that FIFRA’s standard and processes

are the “functional equivalent of a NEPA investig ation” and that “[t]he law requires no more”); Envtl. Def. Fund, Inc. v. Blum, 458 F. Supp. 650, 662 n.6 (D.D.C. 1978) (“If the ‘functional equivalent’ requirement means anything, it surely means that the EPA [in conducting analysis under FIFRA] did not have to follow the detailed procedural requirements laid out by NEPA.”); Douglas Cnty. v. Babbitt , 48 F.3d 1495, 1502-03 (9th Cir. 1995) (“FIFRA for NEPA to apply to FIFRA.”); Merrell v. Thomas , 807 F.2d 776, 782 (9th Cir. 1986) (“FIFRA’s review provisions do afford the public some opportunity to participate in pesticide registration decisions.... [And while that] opportunity would be greater if NEPA [also] applied[,] Congress has made its choice [not to do so].”).Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 7 of 53 

### sediments would be deposited in streams and ri vers, resulting in an es timated $1.4 billion in downstream damage (Gianessi and Reigner 2006).

Throughout the 70-year history of herbicide use, farmers have re gularly dealt with resistance

issues as herbicide uses have resulted in natura l selection of existing tole rant weeds within weed populations. In fact, resistance is a natural and ordinary oc currence that, over time, the agricultural community has addr essed by making adjustments to cultivation practices.

As noted by prominent weed scientists, the mo st effective crop weed management programs use a combination of cultural, mechanical, and/or he rbicide control practices, called diversified weed management practices, instead of relying on one partic ular method of weed control (Beckie, et al. 2011; Hake, et al. 1996; Norsworthy, et al. 2012; University of California 2009; Vargas, et al. 1996). Examples of methods that can be used in a diversified weed management program include: (1) use multiple he rbicides in mixtures, sequences, or rotation, (2) use mechanical tillage such as timely mowing or tilla ge, and/or (3) cultural practices such as crop rotation or other agronomic practices to increase crop compe titiveness (WSSA Resistance management training modules at wssa.net).

The emergence of certain herbicide-resist ant weeds over the past decade, including glyphosate-resistant weed biotypes in certain areas of the U.S., is simply another chapter in the history of herbicide uses. As has been the case in the past, natural sel ection of tolerant weeds has meant that growers have needed to cont inue to adapt and implement evolving weed management strategies. These types of adaptati ons in resistance manageme nt strategies are not

new as weed resistance has occurred for decades . As of January 2014, 416 herbicide-resistant weed biotypes have been reported to be resist ant to 21 different herb icide modes-of-action worldwide (Heap 2014d). Glyphosate-resistant weeds, which occur in certain areas of the U.S., account for approximately 6% of U.S. herbicide -resistant biotypes, while weeds resistant to herbicides that inhibit acetolactate synthase (ALS) and photosynthesis at photosystem (PSII)

inhibitors account for 33% and 17% of the herbicide-resistan t biotypes, respectively (Heap 2014e). Dicamba-resistant and glufosinate-resist ant weeds account for 1% and 0.5% of resistant biotypes respectively (Heap 2014f; g). Again, resi stance occurs naturally in weed populations,

and the use of herbicides selects for the resistan t plants within a population. As discussed further below, Monsanto continues to rely upon the consensus recommendations of leading academic weed scientists who, for several years, ha ve recommended multiple modes of action.

Where necessary to manage herbicide-resistan t weeds in soybean and cotton production, growers

in certain areas of the U.S. have increased herb icide application rates, increased the number of herbicides (number of modes of action), and, in some cases, return ed to more traditional tillage practices (Monsanto 2013a) and hand-weeding (Cul pepper, et al. 2011; NRC 2010). In an effort to manage glyphosate-resistant Palmer amarant h, certain non-glyphosate he rbicides have beenMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 8 of 53 

### reported as being used in conditions and practices that have the potential to result in increased selection of resistant biotypes to those herbicides , thereby putting certain agricultural herbicides in some major herbicide classes at risk (Nichol s, et al. 2010; Prostko 2011) (Dr. Larry Steckel and Dr. Stanley Culpepper, personal communica tions, August 2012). While effective options for managing Ambrosia spp., and Amaranthus spp., including Palmer am aranth, waterhemp and other key broadleaf weeds exist, weed scientis ts have concluded that there is a need for additional herbicide modes-of-action (MOA) to mitigate the potential for development of resistance to the key herbicides essential for weed management in soybean and cotton (Tranel, et al. 2010).

In addition, there has been an increase in the de tection of weed populations with resistance to multiple herbicide modes-of-action (multiple resi stance) in certain weed species, for example,

Amaranthus spp. (Tranel et al. 2010). This devel opment further highlights the need for additional modes of action on certain species. Pres ently there are six broadleaf species known to have populations with multiple re sistance in the U.S., thus limiting the number of herbicide options available for weed control in fields wh ere these populations exist (see Table 1). The emergence of these resistant biotypes demonstrates the continued need to utilize diversified weed management practices, including the need for a dditional herbicide mode s-of-action that are effective in major crops. The WSSA reports: “Weed scientists know that the best defense against weed resistance is to pr oactively use a combination of ag ronomic practices, including the judicious use of herbicides with alternative mode s-of-action either concu rrently or sequentially” (WSSA 2010). Refer to Appendi x B of the November 2013 Peti tioner’s Environmental Report for DTS and DGT Cotton (petitions 10-188-01p and 12-185-01p_a1) (Monsanto 2013b) for

additional details on herbicide resistance.

Importantly, however, evidence to date indicates that resistance to dicamba and auxins is a lower probability than many other herbicides. Indeed, th ere is no evidence of cross-resistance to other herbicide modes-of-action after more than 50 y ears of use of any auxi nic herbicide and where

resistance mechanisms for dicamba have been studie d, there is little to no evidence for the type of mechanism that would suggest the possibility for cr oss-resistance to othe r herbicides modesof-action. Thus, leading experts on resistance to auxi nic herbicides, and in particular dicamba and 2,4-D, are clear in their judgm ent that the evolution of resist ance to dicamba is not likely to

result in cross-resistance to herbicides with other modes-of-action and therefore the risk of dicamba resistance is no greater than the risk of resistance to most other herbicides.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 9 of 53 

### Table 1 – Multiple Resistant Broadleaf Weeds in Soybean and Cotton Production Areas 1

Weed Species Biotypes with Known Resistant

Soybean Production 2 Cotton Production 3

Herbicide MOAs Classes 5 Herbicide MOAs Classes 5 Waterhemp ALS / PS II ALS/PPO

ALS / PPO ALS/PPO/GLY

ALS / GLY

ALS / PS II / PPO

ALS / PPO / GLY

ALS / PS II / HPPD

ALS / PS II / HPPD / GLY

Palmer amaranth ALS / GLY ALS/GLY

ALS / PS II / HPPD Marestail ALS / GLY GLY/Bipyridilium GLY / Bipyridilium

Ragweed spp

. ALS / PPO

ALS / GLY Redroot pigweed ALS / PS II

Kochia 4 ALS / PS II

1 Source: (Heap 2014c)

2 If weed populations with resistance to multiple herbicide modes-of-action are reported in corn or cropland in

states where soybean is grown, thes e populations were also included.

3 If weed populations with resistance to multiple herbicide m odes-of-action are reported in soybean or cropland in

states where cotton is grown, thes e populations were also included.

4 Populations with resistance to dicamba exist; however, no known populations with resistance to both dicamba and

glyphosate exist.

5 ALS (acetolactate synthase inhibitors ), PS II (photosystem II inhibitors ), PPO (protoporh pyrinogen oxidase

inhibitors), GLY (glycines), HPPD (p-hydroxypheny l pyruvate dioxygenase), Bipyridilium (paraquat)Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 10 of 53 

### Benefits of DT Soybean and DGT Cotton for Weed Control and Resistance Management

New herbicide options are needed in soybean and cotton in order to manage present and future growth of resistant weed species, including glyphosate resistant weeds, and species with resistance to multiple herbicides. Today in U. S. soybean and cotton areas the weed species of most concern are broadleaf species, specifically summer annual species such as those in the

Amarathus and Ambrosia genus. Dicamba is an effective herbicide on these and other targeted summer broadleaf species, is compatible and complementary to glyp hosate and will be an essential tool to assist soybean and cotton gr owers to effectively manage weeds and weed resistance in general. The ability to use dicamba on DT soybean and DGT cotton will offer farmers an additional option for management of broadleaf weeds at a time when current herbicide options are becoming more limited because of the spread of biotypes with resistance to multiple herbicides and multiple herbicide modes of action. Dicamba will almost exclusively be

used in combination with othe r herbicides including glyphosate, glufosinate and other soil residual and postemergence active herbicides curre ntly labeled for use in either soybean or cotton. In soybean, there are three basic weed management systems today; a diversified system including multiple herbicides with different m odes of action, herbicides combined with nonherbicide management options, and, to a lesser degree, systems that still rely solely on glyphosate. In cotton, most fa rmers in the southeast, mid-s outh and Texas regions are using diversified weed management programs today, wher eas cotton farmers in the western states are primarily relying only on glyphosate. Dicamba will be incorporated into these existing diversified weed management approaches in bot h soybean and cotton, but will replace in whole or part the use of some curren tly used non-glyphosate herbicides. Furthermore, it is anticipated that the ability to safely use dicamba over th e top of soybean and cotton and the subsequent benefits (e.g., simplicity, flexibility, effectiven ess) of using dicamba will encourage farmers currently relying solely on glyphosat e to incorporate more diversit y into their weed management

programs.

The net effects of dicamba use for weed control in soybean and cotton will be to: (1) further mitigate the potential for evolution of herbicide resistance to glyphosate, dicamba and other herbicides; (2) provide overall better weed contro l for herbicide resistant weeds such as Palmer amaranth and waterhemp, and hard-to-control w eeds such as morningglory and wild buckwheat; (3) help to manage glyphosate-re sistant weeds, therefore preserve and grow conservation tillage

acres and its associated environm ental benefits; (4) increase the adoption of proactive measures to mitigate the evolution and spread of herbicide resistant broadleaf populations 11 

### ; and (5)

11 Grower adoption of recommended weed resistance management programs has increased in recent years, however inconvenience, difficulty or concerns associated with these programs (e.g., plant back intervals, rainfall and/or soil restrictions, crop safety concerns) have been a factor in adoption. Because of the compatibility and complementaryMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 11 of 53 

### displace, in part, some herbicid es that have less benign human health and environment profiles compared to dicamba (e.g., paraquat).

DT soybean and DGT cotton will be sold only in soybean and cotton varie ties that also contain glyphosate-tolerance. Stacking DT soybean and/ or DGT cotton with glyphos ate-tolerant traits

would enable use of a combina tion of different herbicide mode s of action on these crops, an approach that is expected to manage existing hard-to-control and resistant weeds, and mitigate the potential for future development of herbic ide-resistant weeds (Duke and Powles 2009). The use of dicamba for soybean, and dicamba and gl ufosinate for cotton, pr ovides enhanced weed management options in soybean and cotton cultiv ation to control a broad spectrum of broadleaf weed species. These uses of dicamba and glufosin ate also provide effectiv e control of herbicide

resistant broadleaf weeds that have arisen in cer tain areas of the U.S. and which are impacting both conventional and existing ge netically engineered (GE) cr ops. Existing GE crops have provided enormous benefits to fa rmers in recent decades, including improved yields, lower costs, decreased emissions from farm equipment, incr eased use of conservation tillage and associated environmental benefits, and the ability to use he rbicides with a more benign human health and environmental profile. These existing GE crops continue to offer these benefits, and the availability of new herbicide tool s should be used to offset the development of more widespread

selection of resistant we eds so that glyphosate c ontinues to be an impor tant weed management tool nationwide. Today, successful integratio n of DT soybean and DGT cotton can enhance weed management systems by providing additi onal in-crop herbicide modes-of-action, while fostering growers’ use of establ ished production practices, reduced tillage systems, and the same planting and harvesting machinery. DT soybean a nd DGT cotton will also help growers maintain yield and quality to meet the gr owing need for food, feed and fi ber, both domestically and for export markets.

Equally important are the potential negative impact s may result if new herbicide tools such as DT soybean and DGT cotton are not available to U.S. growers: (1) th e number of herbicide resistant weed species and the num ber of acres infested with resi stant weed populat ions would be expected to grow, consequently, additional financial and environmental challenges are likely; and (2) important herbicid e options may lose their effectiven ess forcing growers to incorporate other less economical cultural practi ces. Many weed scientists have speculated that for certain herbicides and weed species (i .e., glufosinate or PPO herbicid es such as flumioxizin and

fomesafen in Amaranthus spp.) resistance will evolve and grow in the absence of new herbicide options (Tranel et al. 2010). Si nce these herbicides are currentl y major tools used to manage glyphosate and ALS resistant Amaranthus spp. in soybean and cotton, farmers will be forced to incorporate mechanical practices which will be less effective and result in a general reduction in yields, as well as loss of conservation tillage acres.

nature of dicamba with the glyphosate-tolerant cropping system, the reluctance of some farmers to implement recommended resistant management programs may be reduced.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 12 of 53 

### Dicamba Resistance: Potential

The auxin herbicide group is the oldest class of herbic ides and includes 2,4 D - the first herbicide

commercialized in the U.S. in the late 1940’s. To date, globally there are only 29 species with

confirmed resistance to auxins. Of these 29 species, there are five species globally with confirmed resistance to dicamba, including four species in the U.S. and Canada, and 17 species with confirmed resistance to 2,4-D in the U.S. (Heap 2014e). This is a relatively low incidence of resistance considering the length of time thes e products have been used and the volume of use in the U.S. and worldwide. This low level of resistance is most likely due to inherent physiological activity of a uxins in plants and genetic factors, as well as how they are generally used in farm level weed management programs (i.e., they are often us ed in conjunction with

other herbicide m ode of actions).

From a physiological and genetics perspective the potential for resist ance to evolve to dicamba is considered low by leading academic experts. A full explanation of these factors was provided by Dr. Mithila Jugulam and J. Christopher Hall as presented in comments submitted on June 24, 2013 to USDA during the DT soybean and DGT cotton EIS Notice of Intent comment period (See Appendix A). These authors also publishe d a scientific paper in 2011 that provided a thorough review of what is known about auxin resistance (Mithila , et al. 2011). As presented and summarized there, the low rate of evolution of resistance to auxins is likely due to: (1) the rare presence of alleles imparting resistance; (2) a fitness penalty associated with resistant alleles; (3) the complex mode of action of these herbicides; (4) the mode of action in plants may be governed by multiple genes which in turn may mean multiple genes are needed for resistance; and (5) in some species, resistance may be conf erred only by recessive genes. Dicamba, 2,4-D

and most other auxins such as MCPA are commonl y used in combinations with other herbicides either as mixtures or in sequences. For dicamba , this is demonstrated in the data provided in Table 2. Also, in use areas such as pastures an d turf, non-chemical weed management activities such as mowing are also used in building divers ified weed management programs and assists in retarding the selection an d proliferation of auxin resistant biotypes. While resistance to dicamba and other auxins has evolved in some species , the evidence indicating a low potential for resistance to evolve does suggest that reason able resistance management practices can be implemented to effectively mitigate or prevent widespread resistance from evolving.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 13 of 53 

### Table 2: Summary of Dicamba Use in U.S. Agricultural Practices

U.S. Total 2012 Treated Acres % Dicamba

Only Total Dicamba (mixtures + alone) Dicamba Only Dicamba Mixtures
Corn 11,919,841 441,945 11,477,896 4% Fallow 6,665,137 17,757 6,647,380 0.3% Winter Wheat 3,622,105 135,020 3,487,085 4% Pastureland 3,221,382 492,671 2,728,711 15% Spring Wheat 1,804,741 79,148 1,725,593 4% Sorghum 1,683,586 49,491 1,634,095 3% Cotton 1,455,312 79,093 1,376,219 5% Soybeans 1,055,926 3,215 1,052,711 0.3% Sugarcane 190,317 - - 0% Source: BASF Corporation market research



### Cross-resistance to other auxin herbicides and he rbicides with different modes of action also

needs to be considered. The best understood case of cross resistance between different

herbicides with different modes of action involves metabolic resistance, specifically hydroxylation of cytochrome P450’s (Powles and Yu 2010). As presented by Drs. Jugulam and Hall in their comments to USDA, the relative potential of dicamba resistance to be a source of

cross-resistance to herbicides with different modes of action is low based upon the research

conducted to date. As th ey state, “Of the 5 species (with re sistance to auxins ) where metabolism has been studied, in only 1 species and herbicid e combination (MCPA resistant hemp-nettle) has metabolism been suspected.” However, the pote ntial for cross-resistance to other herbicides within the auxin group, particul arly cross-resistan ce between dicamba a nd 2,4-D exists, and a few confirmed 2,4-D resistant biotypes have e xhibited resistance to dicamba. However according to available research not all weed spec ies or populations with resistance to 2,4-D are

cross-resistant to dicamba and vice versa (Mithila et al. 2011).

Impact of Dicamba Resistance

As for any herbicide, there is always the potential for resistance to evolve as a function of its use. However, this potential can be reduced by farmer adoption of certain best management practices, foremost of which is to use herbicides in a diversified weed management program within a specific crop and/or across a crop rotation. With the approval of DT soybean and DGT cotton, the use of dicamba for weed control is expected to increase relative to uses in currently approved crops and farming systems. As such, the potential exists for new species to evolve resistance to dicamba. However, the probability of resistan ce developing depends on the weed management practices utilized in current dicamba crops and fa rming systems, as well as the practices that will be employed for the new uses of dicamba in DT soybean and DGT cotton. In evaluating the impact of dicamba resistance, should it arise, it is also important to evaluate the impact ofMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 14 of 53 

### resistance on current uses of dicamba. The following is an assessment of the risk of, and mitigation of the potential for, dicamba resist ance in crops and farming systems where dicamba use is currently approved.

Methods

For this analysis, BASF Corporation market re search information was used to identify and characterize weed management pr actices in the major markets where dicamba is used today. The analysis was conducted by regions because dicamba use and weed management practices can vary across different regions of th e U.S. States were divided into four regions and the states in each region were selected on the basis of wher e soybeans and cotton are primarily grown. The states assigned to each re gion are listed in Table 3.

Table 3: Regional Classifi cations Used in Assessment

Region States

Plains 1 North Dakota, South Dakota, Nebraska, Oklahoma, Kansas, Texas

Delta (Midsouth) 2 Mississippi, Arkansas, Louisiana, Tennessee

Southeast 3 North Carolina, South Carolina, Georgia, Alabama

Midwest 4 Iowa, Illinois, Indiana, Ohio, Minn esota, Wisconsin, Missouri, Michigan

1 The Plains region above is included in Table II.B-2 U.S. So ybean Production by Region and Stat e in 2012: Midwest and Plains

Regions from the November 2013 Environmenta l Report. Cotton is not typically produced in this region, except for Oklahoma

and Texas.

2 The Mid-South region above is included in Table II.B-4 Comm on Weeds in Soybean Production: Southeast region and Table

II.B-15 Common Weeds in Cotton Production in the Mid-South Region of the U.S. from the November 2013 Environmental Report.

3 The Southeast region above is included in Table II.B-4 Comm on Weeds in Soybean Production: Southeast region and Table

II.B-14 Common Weeds in Cotton Production in the Southeast Region of the U.S. from the November 2013 Environmental Report.

4 The Midwest region above is included in Table II.B-3 Co mmon Weeds in Soybean Producti on: Midwest Region from the

November 2013 Environmental Report. Cotton is not typically produced in this region.



## Results and Discussion

Current Dicamba Uses and Identification of Highest Risk Areas

Dicamba herbicides are currently registered for use in asparagus, conser vation reserve programs, corn, cotton, fallow croplands, general farmstead (non cropland), sorghum, grass grown for seed, hay, proso millet, pasture, rangeland, small gr ains, soybeans, sugarc ane, and turf (BASF Corporation 2008). In each region, a subset of labeled crop uses was examined in a marketMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 15 of 53 

### research analysis, see Table 4. The analysis focused on these market segments because they represent the crop segments that could be impacted the most if resistance evolved due to the use of dicamba in DT soybean and DGT cotton. They also represent the highest volumes of dicamba use today. Some dicamba uses list ed in the Clarity herbicide label were not considered relevant to this analysis and have been excluded as follows: (1) grass grown for seed and proso millet because crop production tends to be concentrat ed in the western U.S., which is outside the primary areas of soybean and cotton production; (2) turf uses because the weed targets are different; (3) asparagus because the crop acreag e and use of dicamba is minor; and (4) conservation reserve programs and general farm stead because their weed targets and dicamba use patterns would be similar to uses in fallow and pasture and rangeland.

Dicamba is an effective broadleaf herbicide and is limited to preplant uses in broadleaf crops that lack crop safety 12 

### ; in other crops, dicamba is used in-crop when there is adequate selectivity/crop safety. Dicamba is used in-crop in corn, wheat , grass pastures and sorghum. In soybeans and cotton, dicamba can be safely us ed prior to planting when established plant back intervals are

observed.

Table 4: Dicamba Use by Crop and Year

Crop/Year 2006 2008 2010 2012

Dicamba Treated Acres Corn 8,080,614 8,113,801 6,459,632 11,919,844 Fallow 2,144,260 3,017,717 4,274,678 6,665,140 Wheat, Winter 2,348,897 3,742,572 2,577,953 3,622,102 Pastureland 1,454,649 1,218,179 2,604,944 3,221,382 Wheat, Spring 1,569,079 1,351,665 1,512,894 1,804,742 Sorghum (Milo) 550,795 1,114,162 955,997 1,683,584 Cotton 590,953 589,919 854,649 1,455,309 Soybeans 279,275 529,638 648,509 1,055,926 Sugarcane 198,042 177,089 225,295 190,317 Barley 108,393 211,067 101,158 47,144 Source: BASF Corporation Market Research



### Within the above defined geographical regions, the combined use of dicamba in currently labeled crops and farming systems (e.g., fallow) generally represents a low percentage of total planted acreage of these crops and farming systems (see Ta ble 5). Only in the Plains states – where dicamba is a primary weed control tool in cor n, fallow and sorghum – is dicamba used on more than 10% of the total production area across the crops and farming situations where dicamba is approved for use. (See Table 6 for detailed in formation on dicamba uses in each of the defined geographical regions.) The relativ ely low use of dicamba today across these regions indicates an

overall low level of resistance selecti on pressure on the targeted weeds.

12 Injury can occur when broadleaf crops come in contact with dicamba.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 16 of 53 

### Table 5: Dicamba Treated Acres by Region

Region/Year 2012 Dicamba Treated Acres as % of Planted Area of Crops listed in Table 2 Plains 14% Midsouth 9% Southeast 4% Midwest 3% Monsanto proprietary grower survey data from 2013



### Dicamba Weed Targets

The primary weed targets for dicamba as identifie d by farmers in the market research surveys for each crop/farming system are listed in Table 6. Based on the known weed control spectrum of dicamba, growers applied dicamba to primarily ta rget annual, biennial, and perennial broadleaf weeds, but also targeted a mixture of warm season (summer germinating/growing) and cool season (fall, winter, and spring germinating/grow ing) species. Where the weed spectrum is dominated by cool season species, dicamba applications would mo st likely be in the fall or spring. Conversely, if the weed spectrum is domin ated by warm season species, the applications would be in the late spring and summer. Inform ation on current application timing of dicamba in the various labeled crops is summarized in Table 7.

Characterizing the timing of dicamba applications and associated weed targets is important to understand the intensity of selection pressure on sp ecific species, particularly those that are the target of in-crop applications of dicamba in DT soybean and DGT cotton. In DT soybean and DGT cotton, a summer spectrum (e.g., warm seas on) of broadleaf weeds will be the primary weed targets. Preplant / preemergence uses of dicamba prior to planting of DT soybean or DGT

cotton will be similar to current uses of dicamba in soybeans and cotton today except for the elimination of planting intervals that will allo w dicamba to be applie d before, at and after planting. The major warm season weeds that are th e target of dicamba a pplications in current crop uses are listed in Tabl e 8 through Table 11.

Per the information found in Tables 6 and Appe ndix B, there will be some overlap of dicamba targeted weed spectrums between the new us es in DT soybean and DGT cotton and other crops/farming systems where dicamba is currently us ed, but in many cases there is no overlap of weed species. Note: Appendix B contains a breakdown of common weeds in soybean and cotton by region. In particular, there will be lit tle overlap in the cool season and perennial species that are the focus of dicamba applicati ons today in wheat and pastureland with weed targets for the new uses in DT soybean and DGT cotton. Species common to both current and new uses of dicamba are the warm season species Amaranthus spp. (i.e., Palmer amaranth, waterhemp, redroot pigweed), Ambrosia spp. (i.e., ragweed), mo rningglory, wild buckwheat,Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 17 of 53 

### kochia, cocklebur, and lambsquart ers. Another important target weed common to current and new uses of dicamba is the cool season species, Conyza spp. (i.e., horseweed or marestail). Therefore, with this overlap, a key to managing the potential risk for dicamba resistance in these species due to combined selection pressure across current and new uses is the diversified weed management systems in which dicamba is currently used and expected to be used in DT soybean and DGT cotton. Diversified weed management programs are the key to managing increased selection pressure. Weed management system r ecommendations in DT soybean and DGT cotton, as defined in Monsanto‘s submissions to USDA, will include a combination of herbicides with different modes of action in addition to dicamba and glyphosate, and glufosinate in the case of cotton. The weed management systems in which dicamba is used in currently approved crops and farming systems are defined in the next section.

Weed Management Systems for Current Dicamba Uses

The grower market research data used in this an alysis indicates that dicamba is primarily used today in combination with other herbicides with overlapping activity on dicamba targeted weeds. This is because dicamba expands or complement s the broadleaf activity of a wide range of herbicides. According to market research data (see Table 2) th e application of dicamba in the

absence of another herbicide is at or below 5% of the total dicamba treated acres in each crop/farming system except in pastureland, wher e approximately 15% of dicamba‘s applications

are made in the absence of other herbicides. Th is provides additional evidence that dicamba is generally used in a diversified weed management program with other herbicides and as such will significantly mitigate the evolution of dicamba resi stance as a function of dicamba use in current labeled crops and in DT soybean and DGT cotton, even though ther e is some overlap of weed species between soybean and cotton, and other cr ops where dicamba can be used. Additionally this will significantly mitigate the potential for evolution of dicamba resistance in possible crop rotation systems where dicamba could be used in each rotation.

Herbicide Options to Control Weeds in Current Dicamba Crop Uses

Should resistance to dicamba evolve over time to a ny of the targeted weed species due to any use of dicamba, there will be multiple herbicide opti ons available in the crops and farming systems where dicamba is currently being used. A listing of some of these herbicide options is presented in Table 8 through Table 11. It is important to note that there are multiple herbicide options and multiple modes of action available across the dicamba-labeled crops. Therefore, even if populations where resistance to more than one herbic ide mode of action is pr esent, there is likely

to be an alternative herbicide available for use and therefore minimal impact on production and

herbicide uses in traditional dica mba use areas would be expected.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 18 of 53 

### Scope and Impact of Existing Dicamba Resistant Species

Dicamba-resistant weeds account for 1% of resist ant biotypes today (Heap 2014f). To date, there are four species with known resistant biotyp es to dicamba in the U.S./Canada after over 40 years of use: common hempnettle ( Galeopsis tetrahit ), wild mustard ( Sinapis arvensis) , kochia ( Kochia scoparia) , and prickly lettuce ( Lactuca serriola L

. ) (Heap 2014f).

The dicamba resistant biotypes identified in Canada include common hempnettle and wild mustard. Common hempnettle biotypes identified in barley, cereals, cropland, and wheat in 1998 demonstrated resistance to dicamba, fl uroxypyr, and MCPA (Heap 2014h). Hempnettle is an annual weed most common in the northern pl ains of the U.S. and Canada, where it is generally a target for control in small grains. It is not a common or problematic weed species in soybean or cotton production (See Tables II .B.3 -5 and II.B.14 -17 in the November 2013 Environmental Report).

Wild mustard biotypes with resistance to 2,4-D, dicamba, dichlorpro p, MCPA, mecoprop, and picloram were identified in Canada in 1990 in barley, cropland and wheat (Heap 2014a). Wild mustard is a common cool season weed in many areas of the U.S. It is most often a weed target in no-till situations at the early burndown applic ation before planting crops such as soybeans or

cotton. Wild mustard has not been identified as a major weed in soybean and cotton production (See Tables II.B.3 -5 and II.B.14 -17 in the November 2013 Environmental Report).

Only kochia and prickly lettuce dicamba resistant biotypes have been identified in the U.S.

Dicamba resistance kochia has been confirmed in ND and MT in wheat (1995), ID on roadsides (1997), and NE in corn (2010) (Heap 2014b). Ko chia is not a common or problematic weed species in most soybean and cotton producing areas. However, kochia is a problematic weed in

western sections of Kansas and Nebraska where some soybean is produced. (See Tables II.B.2-4 and Tables II.B.14-17 in the November 2013 Environmental Report). Kochia can also be found in the north Texas cotton growing areas. Add itional herbicide options such as glyphosate, glufosinate, pendimethalin, clomazone, paraquat, fumioxazin, and metribuzin are some of the options available to use in place of dicamba to control dicamba resi stant kochia in these areas. While Kochia populations have also been id entified with glyphosate, PSII (e.g. atrazine, metribuzin) and ALS (e.g. imazethapyr, thifensu lfuron) resistance, not all populations are resistant to these herbicides and they remain effective in many situations.

Prickly lettuce with 2,4-D resistan ce and cross-resistance to MC PA and dicamba was identified in Washington in 2007. Prickly lettu ce is an annual or biennial that is found throughout the U.S. It is not commonly a targeted weed for control in soybeans or cott on since it is primarily found in cereals, orchards, pastures, roadsides, railroad s, and waste areas (See Tables II.B.3 -5 and

II.B.14-17 of the November 2013 Petitioner’s E nvironmental Report (Monsanto 2013a)).Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 19 of 53 

### The persistence of herbicide resist ant biotypes is in part related to the presence or absence of a fitness penalty that may be associated with the resi stant alleles. A fitness penalty is characterized as resistant biotypes being less competitive with non-resistant bi otypes of the same species and therefore less persistent in the environment. As reviewed by Mithila et al. (2011), there is

evidence of reduced fitness in some auxin resist ant biotypes. The presen ce of a fitness penalty has been suggested to be a reason why auxin resistant biotypes do not appear to persist in the

environment.

In summary, of the species with known resist ance to dicamba today, the primary species of

concern relative to the new uses of dicamba in DT soybean and DGT cotton is kochia: its geographical distribution overlaps with some of the soybean and cotton production areas, it is a summer annual, and it would be an in-crop w eed target. The key to mitigating dicamba resistance is implementation of a diverse weed control program th at includes redundant, effective control measures, and scouting to eliminate weed escapes, as noted above, however, there are other herbicide options to manage any dicamba -resistant populations should they arise in both soybeans and cotton.

Weed Resistance Management Stewardship

To support the introduction of varieties containi ng DT soybean and DGT cotton, Monsanto will use multiple methods to distribut e technical and stewardship info rmation to growers, academics and grower advisors regarding the use of the pr oduct as part of a diversified weed management system. Growers who purchase M onsanto varieties cont aining DT soybean or DGT cotton sign a limited use license known as the Monsanto Technology Stewardship Agreement (MTSA). The MTSA obligates growers to comply with ce rtain requirements, including the Monsanto Technology Use Guide (TUG). The TUG will set fo rth the requirements and best practices for the cultivation of DT soybean and DGT cotton including recommendations on weed resistance management practices. Monsanto provides up to date information and resources to assist growers in implementing weed resistance manageme nt strategies through its weed management

website 13 

### and mobile applications.



## Conclusions

With the approval of DT soybean and DGT cotton, there will be an increase in dicamba use and therefore some possibility of an increased potential for resistance to evolve. However, this risk will be greatly mitigated by the fact that dicamba is used in diversified weed management systems today, in current markets, and will likewise be used in diversified weed management systems when dicamba is approved for use in DT soybean and DGT cotton. Monsanto, BASF,

13 http://www.monsanto.com/weedmanagement/Pages/field-management-guidelines.aspxMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 20 of 53 

### the Weed Science Society of America (WSSA), academics and extension service agents have made significant progress in changing grower be havior to adopt diversified weed management practices. On-going and pl anned educational efforts will con tinue to stress the importance of using dicamba in a diversified program, theref ore adoption of diversif ied weed management practices is expected to continue. Moreover, in many instances weeds that are targeted by a dicamba application (i.e., Amaranthus sp. such as Palmer amaranth and waterhemp) require the use of multiple weed control pract ices in order to meet grower weed control expectations, this provides additional assurances that dicamba will be used in a diversified program.

When a herbicide is used in a diversified weed management system that includes other herbicides with overlapping spectr um of control and different mode s-of-action, it can be used repeatedly within a cropping season and across multiple seasons without significantly impacting the risk of resistance (Beckie and Reboud 2009). Therefore, the potentia l for development of dicamba resistance can be significantly mitigated when dicamba-tolerant crops are rotated with each other and/or with crops where dicamba is cu rrently approved. There is strong scientific justification for this conclusion, as indicated by theories of resi stance evolution and management supported by field and resistance modeling stud ies (Beckie and Reboud 2009; Neve, et al. 2011) and the weed science academic community. 14,15,16



### However, the possibility of gradual evolution of resistance (through selection) to any herbicide cannot be completely eliminated if the benefits of the use are to be r ealized. Therefore, an understanding of the impact of this potential re sistance and ways to mitigate the impact are an important part of weed resistance risk assess ment. In this case, options for managing key dicamba targeted weeds in each of the major crops and farming systems where dicamba is used today was evaluated. This analysis supports that the availability of mu ltiple herbicide options with different modes of action will mitigate any pot ential future impacts of dicamba resistance. Likewise, there are multiple options to manage dicamba resistant populations of kochia should

this become an issue in some of the wester n soybean and cotton growing regions where DT soybeans and DGT cotton may be grown. In addition, the potential for development of additional dicamba resistant populations will be mitigated through the use of diversified weed management programs, which include the use of multiple herbicides, in DT soybeans and DGT cotton. The availability of opti ons to manage dicamba resistant populations, plus the indications that resistant biotypes are not as competitive as non-resistant biotypes, both point to low impact of resistant populations on farming operations and the environment.

14 APHIS-2013-0043-0019, available at http://www.regulations.gov/#!doc umentDetail;D=APHIS-2013-0043-0019

15 APHIS-2013-0043-0027, available at http://www.regulations.gov/#!doc umentDetail;D=APHIS-2013-0043-0027

16 APHIS-2013-0043-0054 available at http://www.regulations.gov/#!docum entDetail;D=APHIS -2013-0043-0054Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 21 of 53 

### Lastly, leading experts on resist ance to auxinic herbicides, and in particular dicamba and 2,4-D, are clear in their judgmen t that the evolution of resistance to dicamba is not likely to result in

cross-resistance to herbicides with other mode s of action and therefore the risk of dicamba resistance is no greater than the ri sk of resistance to most other he rbicides. In fact, evidence to

date indicates that resistance to dicamba and auxins is a lo wer probability than many other herbicides. The main reasons for this judgment are that definitive mechan isms for resistance to auxinic herbicides have yet to be defined; there is no eviden ce of cross-resistance to other herbicide modes of action after more than 50 y ears of use of any auxi nic herbicide and where

resistance mechanisms for dicamba have been studie d, there is little to no evidence for the type of mechanism that would suggest the possibility for cro ss-resistance to other herbicides modes of

action.

In closing, the keys to minimizing the impact of resistance to any herbicide are first to mitigate the risk of resistance evolving, and second, to have economical and practical options for managing resistance should it evolve. In the cas e of the proposed new uses of dicamba in DT soybean and DGT cotton, there is ample evidence that the impact of dicamba resistance is minimal and manageable and does not rise to a le vel of concern that would adversely impact the environment nor be of a significant economic bur den to producers. In the unlikely case that broadleaf weeds were to evolve or develop resistance to dicamba over time, existing cultivation and alternative herbicide tools (see Section II .B.2.d in the November 2013 Environmental Report (Monsanto 2013a)) for a desc ription of alternative herbicides) would remain potential options to provide effective control. Addi tionally, any potential risks are far outweighed by the benefits that can be derived from dicamba use to mitigate resistance to other herbicides in an economical

fashion.Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 22 of 53Table 6. Dicamba Weed Targets1Midwest RegionCropDicambaTreatedAcresTotal CropAcresDicambaTreatedas % ofTotal Dicamba Weed Targets (listed in order of treated acres)Corn 3,403,861 56,350,032 6% lambsquartersgiantragweedvelvetleaf redpigweedwaterhemp cocklebur ragweed morning-glorymarestailCotton 210,863 375,002 56% marestail red pigweed chickweed henbit PalmeramaranthPastureland48,788 19,222,408 0% musk thistlebull thistle ragweed CanadathistleSoybeans 85,474 43,690,011 0%marestail waterhemp sweetcloverWheat,Spring10,000 1,400,016 1% red pigweed wildmustardWheat,Winter33,543 3,225,000 1% chickweed velvetleaf giantragweedTotal forRegion3,792,529 124,262,469 3%Southeast RegionCorn 324,511 1,795,003 18% morninggloryred pigweed giantragweedmarestail lambs-quarterbur-cucumbercocklebur sicklepodCotton 73,815 2,469,994 3% marestail eveningprimrosePastureland121,618 6,734,886 2% wild carrot Canadathistlebittersneezeweedredpigweeddandelion dog fennelSoybeans 52,800 2,610,001 2% marestailsmartweedTotal forRegion572,744 4%Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 23 of 53Table 6 (continued). Dicamba Weed Targets1Delta (Midsouth) RegionCropDicambaTreatedAcresTotal CropAcresDicambaTreatedas % ofTotal Dicamba Weed Targets (listed in order of treated acres)Cotton 670,995 1,769,995 38% marestail red pigweed curly dock ragwort eveningprimrosehebitSoybeans 670,148 7,732,424 9% marestail dock ragweed redrootpigMorningglorysicklepod PalmeramaranthCorn 452,712 2,861,05816% marestail Palmeramaranthredroot pig morninggloryhebit dockSugarcane 186,911 425,003 44% morninggloryredrootpigweedcloverPastureland175,758 10,065,529 2% thistle red pigweed bluevervainmarigold dogfennel croton CanadathistleWheat,Winter64,992 888,010 7%Sorghum(Milo)22,578 269,999 8%Fallow 630 91,858 1%Total forRegion2,244,724 24,103,876 9%Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 24 of 53Table 6 (continued). Dicamba Weed Targets1Plains RegionCropDicambaTreatedAcresTotal CropAcresDicambaTreatedas % ofTotal Dicamba Weed Targets (listed in order of treated acres)Barley 12,199 1,174,988 1%Corn 6,234,992 26,270,00824% kochia redrootpigweedwaterhemp RussianthistlelambsquartersPalmeramaranthwildbuckwheatmorninggloryvelvetleafCotton 499,636 7,197,9667% marestail Russianthistlewild mustard ironweed kochia henbit redrootpigweedFallow 3,391,068 6,798,78950% kochia RussianthistleredrootpigweedfieldbindweedpuncturevinewildbuckwheatPalmeramaranthdevils claw marestailPastureland 2,539,862 32,306,093 8%ragweed broomweed marshelder St.johnswortmilkweed sunflower Texasblueweedmild mustardcockleburthistleSorghum(Milo)1,556,474 5,404,99829% kochia redrootpigweedRussianthistlefiledbindweedmildmustardtumplepigweedPalmeramaranthmarestail puncturevineSoybeans 244,253 18,309,988 1% marestail kochia red pigweed henbit waterhemp pennycress wildmustardpepperweedWheat,Spring1,127,246 8,108,00414% kochia Canadathistlebuckwheat fieldbindweedRussianthistleragweed moneywortwild mustardWheat,Winter2,688,190 24,299,99411% kochia redrootpigweedRussianthistleyellowmustardwild mustard fieldbindweedwildbuckwheatfireweed hebitTotal forRegion18,293,920 129,870,828 14%Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 25 of 53 

### Table 7. Timing of Dicamba Applications for Current Crop Uses 1

Crop and Application Timing Sum of Total Area Treated Weed Spectrum of primary application timing

Corn At Planting 104,159 Before Crop Emergence 638,605 Early Post (Herbicides) 672,194

Last Fall 446,739 Late Post (Herbicides) 7,986,902 warm season Prior to Planting 2,071,242 cool season

Corn Total* 11,919,841

Cotton

Last Fall 161,528 Prior to Planting 1,293,784 warm and cool season

Cotton Tota*l 1,455,312

Soybean Last Fall 70,909 Late Post (Herbicides) Prior to Planting 985,017 warm and cool season Soybeans Total* 1,055,926

Sorghum (Milo) At Planting 37,631 Before Crop Emergence 113,617 Early Post (Herbicides) 22,094

Last Fall 593,529 warm season Late Post (Herbicides) 148,849 Prior to Planting 767,866 warm season Sorghum (Milo) Total* 1,683,586

Sugarcane At Planting 1,116 Before Crop Emergence Early Post (Herbicides) 7,958

Last Fall 8,658 Late Post (Herbicides) 94,344 warm season Prior to Planting 78,241 warm season Sugarcane Total* 190,317Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 26 of 53 Table 7 (continued). Timing of Dicamba Applications for Current Crop Uses 1

Crop and Application Timing Sum of Total Area Treated Weed Spectrum of primary application timing

Barley Before Crop Emergence 239 Early Post (Herbicides)

Last Fall 4,764 Late Post (Herbicides) 19,055 warm season Prior to Planting 23,086 cool season Barley Total* 47,144

Wheat, Spring At Planting 26,401 Before Crop Emergence 55,983 Early Post (Herbicides) 2,499

Last Fall 448,317 cool season Late Post (Herbicides) 631,465 warm season Prior to Planting 640,076 cool season Wheat, Spring Total* 1,804,741

Wheat, Winter At Planting 6,838 Before Crop Emergence 12,127 Early Post (Herbicides)

Last Fall 1,176,545 warm and cool season Late Post (Herbicides) 2,426,595 warm season

Wheat, Winter Total* 3,622,105

Fallow
Last Fall 855,875 This Year (Pasture, Fallow) 5,809,262 warm and cool season

Fallow Total* 6,665,137

Pastureland Last Fall 72,524 This Year (Pasture, Fallow) 3,148,858 warm and cool season

Pastureland Total* 3,221,382

1 2012 BASF Market Research Data * Individual crop totals vary slightly from the total dicamba values shown in Table 2 due to rounding of the individual values for each applicati on timing prior to summing all app lication timing acres for each crop.Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 27 of 53Table 8. Herbicide Options to Control Primary Weed Targets in Midwest Region (IA, IL, IN, OH, MN, WI, MO, MI)*CottonMarestail3Pigweed,redroot3Chickweed3Henbit3Palmeramaranth3glufosinate diuron glyphosate glyphosate diuronprometryn fluometuron paraquat oxyflurorfen fluometuronmetolachlor glufosinate paraquat metolachlorfomesafen prometryn prometryn fomesafenNumberherbicideMOAavailable2 4 4 4 3CornLambsquarters1Giantragweed1Velvetleaf1Pigweed,redroot1Waterhemp1Cocklebur1Ragweed,common1Morningglory1Marestail1acetochlor atrazine atrazineacetochlor acetochlor atrazine acetolchlor atrazine atrazine +paraquatatrazine mesotrione isoxaflutole atrazine atrazine mesotrione Atrazine saflufenacil rimsulfuron+mesotrione+ atrazinemesotrione saflufenacil bentazon isoxaflutole isoxflutole saflufenacil saflufenacil mesotrione metolachlor+ atrazine +mesotrionesaflufenacil tembotrione halosulfuron mesotrione mesotrione tembotrione tembotrione carfentrazone saflufenacil+glufosinatetembotrione mesotrione tembotrione tembotrione bentazon bentazon nicosulfuronNumberherbicideMOAavailable4 3 5 4 4 4 5 5 7Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 28 of 53Table 8 (continued). Herbicide Options toControl Primary Weed Targets in Midwest Region (IA, IL, IN, OH, MN, WI, MO, MI)*SoybeanMarestail1Waterhemp1Sweetclover2saflufenacil +glufosinatemetolachlor saflufenacil +glyphosatemetribuzin +glufosinatesulfentrazone saflufenacilchlorimuron +glyphosateflumioxazin glyphosate +fumioxazinfomesafenlactofenNumberherbicideMOAavailable5 2 2Spring WheatPigweed,redroot1Wild mustard1carfentrazone prosulfuronsulfosulfuron sulfosulfuronflorasulam florasulamprosulfuron pyroxsulamNumberherbicideMOAavailable2 1Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 29 of 53Table 8 (continued). Herbicide Options toControl Primary Weed Targets in Midwest Region (IA, IL, IN, OH, MN, WI, MO, MI)*Winter WheatChickweed1Velvetleaf4Giant ragweed1propoxycarbazone carfentrazone prosulfuronflorasulam prosulfuron florasulamprosulfuronpyroxsulamNumberherbicideMOAavailable1 2 1PasturelandThistle, musk5Thistle, bull3,5Ragweed6Thistle, canada5metsulfuron metsulfuron5metsulfuron metsulfuronchlorsulfuron3metsulfuron +chlorsulfuronNumberherbicideMOAavailable1 1 1 1*Source for weed targets was Monsanto proprietary grower survey data from 2012. Weeds listed in descending order according to acres treated with dicamba.Alternative herbicides actives were rated 7-8 and above (good) for control of targeted weed.1Loux, et al. 20132University of Nebraska-Lincoln 20133Mississippi State University 20134University of Missouri 20135University of Arkansas 20136Penn State University 2013Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 30 of 53Table 9. Herbicide Options to Control Primary WeedTargets in Southeast Region (NC, SC, GA, AL)*CottonMarestail5,6Eveningprimrose5paraquat + diuron5tribenuron +thifensulfuronglufosinate6paraquatprometryn6prometrynglufosinateNumberherbicideMOAavailable4 4CornMorningglory1Pigweed,redroot1Giant ragweed2Marestail3Lambsquarters1Burcucumber1Cocklebur1Sicklepod1atrazine acetochloratazine mesotrione +atrazineatrazine atrazineatrazine atrazineflumetsulam atrazine mesotrione glufosinate flumetsulam primsulfuron flumetsulam flumetsulammesotrione flumetsulam saflufenacil tembotrione +atrazinemesotrione paraquat mesotrione primsulfuronforamsulfuron mesotrione tembotrione topramezone +atrazinecarfentrazone foramsulfuroncarfentrazone glyphosateNumberherbicideMOAavailable4 4 4 3 4 4 4 3Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 31 of 53Table 9 (continued). Herbicide Options to Control Primary Weed Targets in Southeast Region (NC, SC, GA, AL)*SoybeanMarestail4Smartweed4paraquat +metribuzinmetribuzinglufosinate clomazonebentazonlactofenNumberherbicideMOAavailable3 4PasturelandWild carrot Thistle,canada7Bittersneezeweed7Thistles7Pigweed,redroot7Dandelion7Dogfennel7metsulfuron +chlorsulfuronmetsulfuron metsulfuron +chlorsulfuronflumioxazin flumioxazin metsulfuron+chlorsulfuronmetribuzin tebuthiuron metribuzin metsulfuron metsulfurontebuthiuronhexazinone metsulfuron +chlorsulfuronhexazinone metribuzin tebuthiuronhexazinone hexazinoneNumberherbicideMOAavailable2 2 2 3 4 2*Source for weed targets was Monsanto proprietary grower survey data from 2012. Weeds listed in descending order according to acres treated with dicamba.1University of Georgia 2013c2Loux et al. 20133University of Tennessee 20134University of Georgia 2013aMonsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 32 of 535University of Georgia 2013b6Mississippi State University 20137McCullough 2008Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 33 of 53Table 10. Herbicide Options to Control Primary Weed Targets in Delta Region (MS, AR, LA, TN)*CottonMarestail1Pigweed,redroot1Dock, curly1Ragwort, tansyEveningprimrose1Henbit1glufosinate diuron tribenuron +thifensulfurontribenuron +thifensulfurontribenuron +thifensulfuronprometryn fluometuron oxyflurorfen paraquat glyphosatemetolachlor paraquat prometryn paraquatglufosinate prometryn glufosinate prometrynpendimethalinNumberherbicideMOAavailable2 4 4 4 4CornMarestail2Palmeramaranth1Pigweed,redroot1Morningglory1Henbit3Dock3mesotrione +atrazineatrazine atrazine atrazine glyphosate glyphosateglufosinate acetochloracetochlor simazine paraquat glyphosate +flumioxazintembotirone +atrazinesaflufenacil saflufenacil pyroxasulfone glyphosate +flumioxazintopramezone +atrazinemesotrione mesotrione mesotrioneglyphosateNumberherbicideMOAavailable3 4 4 4 3 2Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 34 of 53Table 10 (continued). Herbicide Options to Control Primary Weed Targets in Delta Region (MS, AR, LA, TN)*SoybeanMarestail3Dock, sour1,3Ragweed1Pigweed,redroot1Morningglory1Sicklepod1Palmeramaranth1metribuzin +chlorimurontribenuron +thifensulfuron1metribuzin dimethenamid imazaquin fumioxazin dimethenamidflumioxazin glyphosate +oxyflurorfen1paraquat fomesafen fumioxazin metribuzin metribuzinmetribuzin glyphosate +fumioxazin3fomesafen metribuzin chlorimuron chlorimuron fomesafenchloransulam fumioxazin pendimethalinmetribuzin fomesafen acetochlorchlorimuron chlorimuron glyphosate chloransulam fumioxazinNumberherbicideMOAavailable3 3 4 5 4 3 3SugarcaneMorningglory5,6Pigweed,redroot5,6Clover5atrazine atrazine atrazineflumioxazin flumioxazin flumioxazinsulfentrazone sulfentrazonesulfentrazonemetribuzin metribuzin metribuzinNumberherbicideMOAavailable2 2 2Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 35 of 53Table 10 (continued). Herbicide Options to Control Primary Weed Targets in Delta Region (MS, AR, LA, TN)*PasturelandThistle3Pigweed,redroot3Ragweed3Vervain, blue Marigold, dwarf Dogfennel3,4Croton,woolly3metsulfuron +chlorsulfuronmetsulfuron +chlorsulfuronmetsulfuron +chlorsulfuronmetsulfuron +chlorsulfuron3nicosulfuron +metsulfuronchlorsulfuron chlorsulfuron metsulfuron tebuthiruron4metsulfuronnicosulfuron +metsulfuronNumberherbicideMOAavailable1 1 1 2 1*Source for weed targets was Monsanto proprietary grower survey data from 2012. Weeds listed in descending order according to acres treated with dicamba.Alternative herbicides actives were rated 7-8 and above (good) for control of targeted weed.1Mississippi State University 20132University of Tennessee 20133University of Arkansas 20144University of Georgia 2013a5Louisiana State University 20136Product Labels on CDMS website [http://www.cdms.net/LabelsMsds/LMDefault.aspx?t=]Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 36 of 53Table 11. Herbicide Options to Control Primary Weed Targets in Plains Region (ND, SD, NE, KS, OK, TX)*CottonMarestailThistle, RussianMustard, wildIronweedKochiaHenbitPigweed, redroot4pendimethalinfluometurondiuronmetolachlorfumioxazincarfentrazonelactofenNumberherbicideMOAavailable4Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 37 of 53Table 11 (continued). Herbicide Options to Control Primary Weed Targets in Plains Region (ND, SD, NE, KS, OK, TX)*CornKochia1Pigweed,redroot1Waterhemp1Thistle,Russian1Lambsquarters1Palmeramaranth1Buckwheat,wild2Morningglory1Velvetleaf1atrazine atrazine atrazineatrazine atrazine atrazineatrazine atrazine atrazineisoxaflutole isoxaflutole isoxaflutole isoxaflutole isoxaflutole isoxaflutole saflufenacil saflufenacil isoxaflutolemesotrione mesotrione mesotrione mesotrione mesotrione mesotrione glyphosate carfentrazone mesotrionesaflufenacil saflufenacil saflufenacil saflufenacil saflufenacil saflufenacil glufosinate foramsulfuron saflufenacilprimsulfuron tembotrione tembotrione tembotrioneacetochlor tembotrione bentazon carfentrazoneacetochlor acetochlor glyphosate carfentrazone acetochlorthiencarbazone+ tembotrionefluthiacettembotrione glyphosateglyphosate tembotrioneNumberherbicide MOAavailable5 5 5 5 6 5 6 3 5Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 38 of 53Table 11 (continued). Herbicide Options to Control Primary Weed Targets in Plains Region (ND, SD, NE, KS, OK, TX)*SoybeanMarestail1Kochia1Pigweed,redroot1Henbit1Waterhemp1Pennycress1Mustard, wild3paraquat pendimethalin metolachlor glyphosate metolachlor glyphosate carfentrazonesaflufenacil clomazone metribuzin paraquat metribuzin paraquat metribuzinflumioxazin/glyphosate cloransulam flumioxazin imazethapyr flumioxazin imazethapyr bentazonmetribuzin/chlorimuron metribuzin cloransulam imazaquin pendimethalin imazaquin acifluorfencloransulam flumioxazinPendimethalin saflufenacil fluthiacetsaflufenacil chlorimuronfluthiacet fluthiacetacifluorfen fomesafenNumberherbicide MOAavailable5 5 5 4 4 4 4Spring WheatKochia1,5Thistles5Buckwheat5Bindweed,fieldThistle,russian1Ragweed Moneywort Mustard,Wild5Carfentrazone5triasulfuron**Carfentra-zoneno productsfound metsulfuron** triasulfuronSaflufenacil5metsulfuron** triasulfuron triasulfuron** metsulfuronImazamethabenz**chlorsansulam+ metsulfuron metsulfuron prosulfuron** florasulamtriasulfuron1prosulfuron florasulam prosulfuronprosulfuronNumberherbicide MOAavailable2 1 2 1 1Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 39 of 53Table 11 (continued). Herbicide Options to Control Primary Weed Targets in Plains Region (ND, SD, NE, KS, OK, TX)*Winter WheatKochia1,5Pigweed,redroot1Thistle,russian1Mustard,yellow5Mustard,wild5Bindweed,fieldBuckwheat,wild5carfentrazone metsulfuron metsulfuron** triasulfuron triasulfuron no productsfoundcarfentrazonesaflufenacil triasulfuron triasulfuron** metsulfuron metsulfuron triasulfuronImazamethabenzprosulfuron prosulfuron** florasulam florasulam metsulfurontriasulfuron1prosulfuron prosulfuron florasulamprosulfuronNumberherbicideMOAavailable2 1 1 1 1 2SorghumKochia1Pigweed,redroot1Thistle,russian1Bindweed,field6Mustard,wildPigweed,tumble1Palmeramaranth1Marestail1dimethenamid/atratrazine atrazine quinclorac +atrazineatrazine atrazine mesotrione/metolachlor/atrazineatrazine acetochlor/atrazineacetochlor/atrazineCarfenterazone*acetochlor +atrazineacetochlor+atrazinesaflufenacilsaflufenacil carfentrazone saflufenacil carfentrazonecarfentrazonehalosulfuron halosulfuron halosulfuronsaflufenacil saflufenacil saflufenacilNumberherbicideMOAavailable3 4 3 1 4 4 4Monsanto Company Petitions 10-188-01p/12-185-01p_a1 Page 40 of 53Table 11 (continued). Herbicide Options to Control Primary Weed Targets in Plains Region (ND, SD, NE, KS, OK, TX)*PasturelandRagweed4Broomweed4Marshelder St. Johnswort Milkweed Sunflower4Blueweed,Texasmetsulfuron metsulfuron metsulfuronmetsulfuron +chlorsulfuronmetsulfuron +chlorsulfuronmetsulfuron +chlorsulfuronmowing mowingNumberherbicideMOAavailable1 1 1Mustard, wild Cocklebur,spiny4Thistle4metsulfuron metsulfuronmetsulfuron +chlorsulfuronmetsulfuron +chlorsulfuronmowing mowingNumberherbicideMOAavailable1 1*Source for weed targets was Monsanto proprietary grower survey data from 2012. Weeds listed in descending order according to acres treated with dicamba.Alternative herbicides actives were rated 7-8 and above (good)for control of targeted weed except where identified with**which includes ratings of marginalcontrol.1University of Nebraska-Lincoln 20132Moechnig, et al. 20113Moechnig, et al. 2012a4Kansas State University 20145Moechnig, et al. 2012b6Moechnig, et al. 2010Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 41 of 53 

## Appendix A

Comments submitted by Dr. C. Hall and Dr. M. Jugulam to DT soybean MON 87708 and DGT Cotton MON 88701 Notice of Intent scoping comment periodMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 42 of 53Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 43 of 53Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 44 of 53Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 45 of 53 

## Appendix B

Common weeds in soybean and cotton production.

This appendix contains information on the comm on weeds in soybean and cotton by region from the November 2013 Petitioner’s Environmenta l Report for DT Soybean MON 87708 and DGT Cotton MON 88701.

Common Weeds in Soybean Production: Midwest Region

Foxtail spp. (12) 1 Ragweed, giant (3) Dandelion (1) Pigweed spp. (11) Shattercane (3) Johnson grass (1) Velvetleaf (11) Quackgrass (3) Milkweed, honeyvine (1) Lambsquarters (10) Buckwheat, wild (2) Nightshade, hairy (1) Cocklebur (9) Crabgrass spp. (2) Oats, wild (1) Ragweed, common (7) Kochia (2) Pokeweed, common (1) Smartweed spp. (6) Mustard, wild (2) Prickly sida (1) Morningglory spp. (5) Nightshade, Eastern black (2) Proso millet, wild (1) Sunflower, spp. (5) Palmer amaranth (2) Sandbur, field (1) Waterhemp spp. (5) Canada thistle (1) Venice mallow (1) Horseweed (marestail) (3) Chickweed (1) Volunteer cereal (1) Panicum, fall (3) Cupgrass, woolly (1) Volunteer corn (1)

Dicamba is effective on w eeds highlighted in bold.

1 Number provided in parenthesis is the number of stat es out of the thirteen total states in the Midwest region reporting each weed as a common weed. Sources: IL: University of Illinois (2002) and Aaron Hager, Ex tension Weed Specialist, University of Illinois - Personal Communication (2006). IN: 2003-2005 Statewide Purdue Horseweed Weed Survey, Special database query and personal communication (2006), Bill Johnson, Extensi on Weed Specialist, Purdue University. IA, MN, OH, WI: (WSSA 1992). KS: Dallas Petersen, Extension Weed Specialist, Kansas State - Personal communication (2006). KY, MO: (Webster, et al. 2005). MI: (Davis, et al. 2005). NE: Alex Martin, Extension Weed Specialist, Univer sity of Nebraska – Personal communication (2006). ND: (Zollinger and Lym 2000). SD: Michael Moechnig, Extension Weed Specialist, South Dakota State University – Personal communication (2006).Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 46 of 53 Common Weeds in Soybean Production: Southeast Region

Morningglory spp. (8) 1 Goosegrass (3) Cutleaf evening-primrose (1) Crabgrass spp. (6) Johnsongrass (3) Groundcherry (1) Prickly sida (6) Ragweed, common (3) Henbit (1) Nutsedge spp. (6) Cocklebur (2) Lambsquarters (1) Sicklepod (5) Florida beggarweed (2) Ragweed, giant (1) Signalgrass, broadleaf (5) Hemp sesbania (2) Smartweed (1) Palmer amaranth (4) Horseweed (marestail) (2) Spurge, nodding/hyssop (1) Pigweed spp. (4) Texas millet (2) Spurge, Prostrate (1) Barnyard grass (3) Browntop millet (1) Tropic croton (1) Florida pusely (3) Copperleaf, hophorn (1)

Dicamba is effective on w eeds highlighted in bold.

1 Number provided in parenthesis is the number of states out of the eight total states in the Southeast region reporting each weed as a common weed. Sources: AL, AR, GA, LA, NC, SC: (Webster, et al. 2009). MS, TN: (Webster et al. 2005).



### Common Weeds in Soybean Production: Eastern Coastal Region

Foxtail spp. (6) 1 Morningglory spp. (4) Dandelion (1) Ragweed, common (6) Panicum, fall (4) Goosegrass (1) Velvetleaf (6) Crabgrass spp. (3) Johnson grass (1) Lambsquarters (5) Nutsedge spp. (3) Nightshade, Eastern black (1) Pigweed spp. (5) Quackgrass (2) Prickly sida (1) Cocklebur (4) Canada thistle (1) Shattercane (1) Jimson weed (4) Burcucumber (1) Smartweed spp. (1)

Dicamba is effective on w eeds highlighted in bold.

1 Number provided in parenthesis is the number of states out of the six total states in the Eastern Coastal region reporting each weed as a common weed. Data were not available for DE in soybean. Sources: DE, MD, NJ, PA: (WSSA 1992). NY: Russell Hahn, Extension Weed Specialist, Corn ell University – Personal Communication (2006). VA: (Webster et al. 2009).Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 47 of 53 

### Common Weeds In Cotton Production

Common weeds in Cotton Production in the Southeast Region of the U.S. 1,2

Crabgrass spp. (6) Morningglory spp (6) Prickly sida (5) Florida pusley (4) Nutsedge spp. (4) Sicklepod (4)

Broadleaf signalgrass (3) Goosegrass (3) Pigweed spp (3) Common cocklebur (2) Common lambsquarters (2) Common ragweed (2) Florida beggarweed (2) Palmer amaranth (2) Texas millet (2) Bermudagrass (1) Crowfootgrass (1) Horseweed (marestail) (1) Jimsonweed (1) Johnsongrass (1) Smartweed spp. (1) Spurge spp (1) Volunteer peanut (1)

Dicamba is effective on w eeds highlighted in bold.

1 Source: (Webster et al. 2009).

2 Number provided in parenthesis is th e number of states out of the six total states (AL, FL, GA, NC, SC, & VA) in the Southeast Region reporting each w eed as one of the ten most common weeds.



### Common weeds in Cotton Production in the Midsouth Region of the U.S. 1,2

Morningglory spp (5)

Broadleaf signalgrass (4) Crabgrass spp (4) Nutsedge spp (4) Prickly sida (4) Spurge spp (4) Pigweed spp (3) Velvetleaf (3) Barnyardgrass (2)

Horseweed (marestail) (2) Johnsongrass (2) Palmer amaranth (2) Bermudagrass (1) Browntop millet (1) Common cockleburr (1)Cutleaf eveningprimrose (1) Goosegrass (1) Hemp sesbania (1) Henbit (1) Spurred anoda (1)

Dicamba is effective on w eeds highlighted in bold.

1 Source: (Webster et al. 2005; Webster et al. 2009) Webster et al., 2005 (MS & TN); Webster et al., 2009 (AR, LA, & MO).

2 Number provided in parenthesis is the number of stat es out of the five total states (AR, LA, MS, MO, & TN) in the Midsouth Region reporting each w eed as one of the ten most common weeds.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 48 of 53 

### Common weeds in Cotton Production in the Southwest Region of the U.S. 1,2

Johnsongrass (4) Nutsedge spp (4)

Common cockleburr (3) Palmer amaranth (3)

Silverleaf Nightshade (3)

Common lambsquarters (2) Large Crabgrass (2) Devil's claw (2) Morningglory spp (2) Mustard spp (2) Pigweed spp (2) Russian thistle (2) Barnyardgrass (1) Bermudagrass (1) Bindweed, field (1) Foxtail spp (1) Groundcherry spp (1) Kochia (1)

Horseweed (marestail) (1) Shepardspurse (1) Smartweed (1) Smellmelon (1) Spurred anoda (1) Red Sprangletop (1) Sunflower (1) Texas blueweed (1) Texas millet (2) Velvetleaf (1) Woolyleaf bursage (1)

Dicamba is effective on w eeds highlighted in bold.

1 Source: OK - (Webster et al. 2009); KS – Dr. St ewart Duncan, Kansas State University – Personal Communication 11/4/2010; NM – Dr. Jamshid Ashigh, New Mexico State University – Personal Communications 11/12/2010; TX – Dr. Wayne Keeling and Dr. Gaylon Morgan, Texas A&M University - Personal communications 11/4/2010.

2 Number provided in parenthesis is the number of stat es out of the four total states (KS, OK, TX, & NM) in the Southwest Region re porting each weed as one of the ten most common weeds.



### Common weeds in Cotton Production in the West Region of the U.S. 1,2

Barnyardgrass (2) Morningglory spp (2) Sprangletop (2) Bermudagrass (1) Field Bindweed (1) Cupgrass, southwestern (1) Groundcherry spp (1) Common lambsquarters (1) Johnsongrass (1) Junglerice (1) Nutsedge spp (1) Pigweed spp (1) Black Nightshade (1) Hairy Nightshade (1) Silverleaf Nightshade (1) Palmer amaranth (1) Common Purslane (1) Horse Purslane (1) Volunteer corn (1)

Dicamba is effective on w eeds highlighted in bold.

1 Source: AZ – Bill McCloskey, University of Ar izona – Personal Communication 11/5/2010; CA – Steven Wright, University of California - Personal Communication 11/16/2010.

2 Number provided in parenthesis is the number of st ates out of the two total states (AZ & CA) in the West Region reporting each weed as one of the ten most common weedMonsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 49 of 53 

## References

BASF Corporation. 2008. Clarity ® 

### herbicide label. BASF Corpor ation, Research Triangle Park, North Carolina.

Beckie, H.J., K.N. Harker, L.M. Hall, F.A. Ho lm and R.H. Gulden. 2011. Risk assessment of glyphosate resistance in West ern Canada. Weed Technology 25:159-164.

Beckie, H.J. and X. Reboud. 2009. Selecting for weed resistance: Herbicide rotation and mixture. Weed Technology 23:363-370.

Culpepper, A.S., A.C. York and L.E. Steck el. 2011. Glyphosate-resist ant Palmer amaranth management in cotton. 2011 Proceedings, Southern Weed Science Society, San Juan, Puerto Rico.

Davis, A., K. Renner, C. Sprague, L. Dyer a nd D. Mutch. 2005. Integrat ed weed management: One year's seeding. Extension Bulletin E-2931. Michigan State University, East Lansing, Michigan.

Duke, S.O. and S.B. Powles. 2009. Glyphosate-resistant crops and weeds: Now and in the future. AgBioForum 12:346-357.

Gianessi, L. and N. Reigner. 2006. The value of herbicides in U.S. crop production: 2005 update. CropLife Foundation, Washington, D.C.

Hake, S.J., T.A. Kerby and K.D. Hake. 1996. Prep aration for the new crop season - Fall/winter. Pages 6-14 in Cotton Production Manual. S.J. Hake, T.A. Kerby, and K.D. Hake (eds.). University of California Division of Agricult ure and Natural Resources, Davis, California.

Heap, I. 2014a. Group O/4 resistant wild mustard ( Sinapis arvensis ): Synthetic auxins (O/4), Canada, Manitoba. WeedScience.org, Internatio nal Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/De tails/Case.aspx?ResistID=55 [Accessed January 16, 2014].

Heap, I. 2014b. Herbicide resi stant kochia globally ( Kochia scoparia ). WeedScience.org, International Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/summary/Species.aspx [Accessed January 16, 2014].

Heap, I. 2014c. Multiple resistance by biotype in USA. WeedScience.org, International Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/ testlive/usmultiplecases.aspx [Accessed January 16, 2014].Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 50 of 53 

### Heap, I. 2014d. International survey of herbic ide resistant weeds summary. WeedScience.org, International Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/summary/home.aspx [Accessed January 15, 2014].

Heap, I. 2014e. Herbicide-resistant weeds by si te of action. WeedScie nce.org, International Survey of Herbicide Resistan t Weeds, Corvallis, Oregon. http://www.weedscience.org/summary/SOASummary.aspx [Accessed January 15, 2014].

Heap, I. 2014f. Weeds resistant to the herbicide dicamba. WeedScie nce.org, International Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/summary/ResistbyActive.aspx [Accessed January 15, 2014].

Heap, I. 2014g. Weeds resistant to the herbic ide glufosinate-ammonium. WeedScience.org, International Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/summary/ResistbyActive.aspx [Accessed January 15, 2014].

Heap, I. 2014h. Group O/4 resistant common hempnettle ( Galeopsis tetrahit ): Synthetic auxins (O/4), Canada, Alberta. WeedSc ience.org, International Survey of Herbicide Resistant Weeds, Corvallis, Oregon. http://www.weedscience.org/De tails/Case.aspx?ResistID=1154 [Accessed January 16, 2014].

Kansas State University. 2014. 2014 chemical weed control. Report of Progress 1099. Kansas State University Agricultural Experiment Stati on and Cooperative Extension Service, Manhattan,

Kansas.

Louisiana State University. 2013. Louisiana s uggested chemical weed management guide. Louisiana State University, Baton Rouge, Louisiana.

Loux, M.M., D. Doohan, A.F. Dobbels and B. Reeb. 2013. 2013 weed control guide for Ohio and Indiana. The Ohio State University Extens ion, Purdue Extension, West Lafayette, Indiana.

McCullough, P.E. 2008. Weed response to herbicid es used in pasture, hay and forage crops. University of Georgia Ex tension, Griffin, Georgia.

Mississippi State University. 2013. 2013 weed control guidelines for Mississippi. Mississippi State University, Mississi ppi State, Mississippi.

Mithila, J., J.C. Hall, W.G. Johnson, K.B. Kelley and D.E. Riechers. 2011. Evolution of resistance to auxinic herbicides: Historical perspectives, mechanisms of resistance, and implications for broadleaf weed manage ment in agronomic crops. Weed Science 59:445-457.

Moechnig, M., D.L. Deneke and L.J. Wrage. 2010. Weed control in sorghum: 2010. FS525D. South Dakota State University Ex tension, Brookings, South Dakota.

Moechnig, M., D.L. Deneke and L.J. Wrage. 2011. Weed control in corn: 2011. FS525C. South Dakota State University Exte nsion, Brookings, South Dakota.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 51 of 53 

### Moechnig, M., D.L. Deneke, L.J. Wrage, J. Alms, D. Vos and M. Rosenberg. 2012a. Weed control in soybeans: 2012. South Dakota St ate University, Brookings, South Dakota.

Moechnig, M., D.L. Deneke, L.J. Wrage and M. Rosenberg. 2012b. Weed control in small grains: 2012. South Dakota State Univers ity Extension, Brookings, South Dakota.

Monsanto. 2013a. Petitioner’s environmental report for dicamba-tolerant soybean MON 87708 and dicamba- and glufosinate-tolerant cotton MON 88701. November 22, 2013. Monsanto Company, St. Louis, Missouri.

Monsanto. 2013b. Supplemental information to suppor t the NEPA analysis for the determination of nonregulated status of dicamba-tolerant s oybean MON 87708 and dicamba- and glufosinatetolerant cotton MON 88701. December 19, 2013. M onsanto Company, St. Louis, Missouri.

Neve, P., J.K. Norsworthy, K.L. Smith and I. A. Zelaya. 2011. Modeling glyphosate resistance management strategies for Palmer amaranth ( Amaranthus palmeri ) in cotton. Weed Technology 25:335-343.

Nichols, R., K. Balkcom, S. Culpepper, M. Marshall, D. Monks, M. Patterson, A. Price and L. Steckel. 2010. Meeting the challenge of glyphosate- resistant Palmer amaranth in conservation tillage. Cotton, Inc., Cary, North Carolina.

Norsworthy, J.K., S.M. Ward, D.R. Shaw, R.S. Llewellyn, R.L. Nichols, T.M. Webster, K.W. Bradley, G. Frisvold, S.B. Powles, N.R. Burgos , W.W. Witt and M. Barrett. 2012. Reducing the risks of herbicide resistance: Best management practices and recommendations. Weed Science 60:31-62.

NRC. 2010. Impact of genetically en gineered crops on farm sustainability in the United States. National Research Council, The Nationa l Academies Press, Washington, D.C.

Penn State University. 2013. The agronomy guid e, 2013-2014. Penn State University, State College, Pennsylvania.

Powles, S.B. and Q. Yu. 2010. Evolution in action: Plants resistant to herbicides. Pages 317-347 in Annual Review of Plant Biology. Volume 61. Annual Reviews, Palo Alto, California.

Prostko, E.P. 2011. Developing an herbicide-resist ant weed management plan. University of Georgia College of Agricultural and E nvironmental Sciences, Tifton, Georgia.

Tranel, P.J., C.W. Riggins, M.S. Bell and A.G. Hager. 2010. Herbicide resistances in Amaranthus tuberculatus : A call for new options. Journal of Agricultural and Food Chemistry 59:5808-5812.

University of Arkansas. 2013. Pasture weed and brush control. FSA2080. University of Arkansas Division of Agriculture, Cooperative Exte nsion Service, Fayetteville, Arkansas.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 52 of 53 

### University of Arkansas. 2014. Recommended chem icals for weed and brush control. MP44. University of Arkansas Division of Agricultur e, Cooperative Extension Service, Fayetteville, Arkansas.

University of California. 2009. Cotton: Integrated weed management. Univ ersity of California IPM Online, Statewide Integrated Pest Manage ment Program, Davis, California. [Accessed April 17, 2013].

University of Georgia. 2013a. 2013 Georgia soyb ean production guide. University of Georgia Cooperative Extension, Tifton, Georgia.

University of Georgia. 2013b. 2013 Georgia cott on production guide. University of Georgia Cooperative Extension, Tifton, Georgia.

University of Georgia. 2013c. A guide to co rn production in Georgi a 2013. University of Georgia Cooperative Exte nsion, Tifton, Georgia.

University of Missouri. 2013. Pest management guide: Corn, grain sorghum, soybean, winter wheat, rice, cotton. M171. University of Missouri Extension, Co lumbia, Missouri.

University of Nebraska-Lincoln. 2013. 2013 guide for weed management in Nebraska. EC130. University of Nebraska-Lincoln Extension, Lincoln, Nebraska.

University of Tennessee. 2013. 2013 weed control manual for Tennessee. PB 1580. University of Tennessee Extension, Knoxville, Tennessee.

Vargas, R.N., W.B. Fischer, H.M. Kempen and S.D. Wright. 1996. Cotton weed management. Pages 187-188 in Cotton Production Manual. S.J. Hake, T.A. Kerby, and K.D. Hake (eds.). University of California Division of Agricult ure and Natural Resources, Davis, California.

Webster, T.M., M. Patterson, J. Everest, J. Ferrell, B. Brecke, A.S. Culpepper, E.P. Prostko, J.D. Green, J.R. Martin, E.Webster, S. Kelly, J. Gri ffin, D. Sanders, J. Byrd, A. Kendig, A. York, D. Jordan, L. Fisher, C. Medlin, D. Murray, J. Norsworthy, J. Chapin, L. Nelson and L. Steckel. 2005. Weed survey - Southern states 2005: Broadl eaf crops subsection (cotton, peanut, soybean, tobacco, and forestry). Pages 291-306 in 2005 Proceedings of the Southern Weed Science Society, Memphis, Tennessee.

Webster, T.M., M. Patterson, J. Everest, K. Smith, D. Oliver, J. Norsworthy, N. Burgos, B. Scott, J. Byrd, C. Fristoe, J. Ferrell, B. Brecke, P. Minogue, A.S. Culpepper, E.P. Prostko, D. Moorhead, J.M. Moore, J.D. Green, J.R. Mar tin, B. Williams, D. Stephenson, D. Miller, D. Sanders, J. Griffin, K. Bradley, A. York, D. Jo rdan, L. Fisher, D. Murray, M. Marshall, S. Hagood and C. Johnson. 2009. Weed survey - Southe rn states 2009: Broadl eaf crops subsection (cotton, peanut, soybean, tobacco, and forestry ). Pages 509-524 in 2009 Proceedings of the Southern Weed Science Soci ety, Las Cruces, New Mexico.Monsanto Company Petitions 10-188-0 1p/12-185-01p_a1 Page 53 of 53 

### WSSA. 1992. Tables. Pages 88, 103, 107, 118, 123, 130, 145, 393-401 in Crop Losses Due to Weeds in the United States. D.C. Bridges (ed.). Weed Science Society of America, Champaign, Illinois.

WSSA. 2010. WSSA supports NRC findings on w eed control. Weed Science Society of America, Champaign, Illinois.

Zollinger, R. and R. Lym. 2000. Identification a nd control of field bindweed. North Dakota State University Extension, Fargo, North Dakota. http://www.ag.ndsu.edu/pubs/plantsci/weeds/w802w.htm [Accessed March 26, 2010].