UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 

### MAR 4 2016

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION MEMORANDUM SUBJECT:

FROM:

THRU:

TO: BEAD Chemical Profile (BCP) for Registration Review: Fluometuron (PC 035503) Sunil Ratnayake, Ph.D. , Biologist

# ~**~ ~** **~** Biological Analysis Branch \ 

### ''"'-JI '

.

## ~ Jihad Alsadek, Ph.D. , Economist ../

# ~**~ jf~**  Science Information and Analysis Branch Stephen Smearman, Economist 

# L
.._

_

/.•7 ,.

## ~ Economic Analysis Branch

### ' 1 Biological and Economic Analysis Division (7503P) Mark Suarez, Acting Chief

# ~ 

# A

---- Biological Analysis Branch 

## 'V\J**~** 

## . Diann Sims,

# Chief**~** Science Information and Analysis Branch Timothy Kiely, Chief 

# sn \

I\. J\

# ~ Economic Analysis Branch \JV\ Biological and Economic Analysis ivision (750 · Linsey Walsh, Chemical Review Manager Risk Management and Implementation Branch 3 Pesticide Re-evaluation Division (7508P) 

### Peer Review Panel date: September 23, 2015SUMMARY Fluometuron is a selective herbicide that is used to control broadleaf and grass weeds; cotton is the only registered use site. It was first registered in the United States in 1974 and re-registered in 2004 (USEPA, 2005). According to the Weed Science Society ofAmerica (WSSA) , fluometuron belongs to the phenylurea family ofherbicides (Group 7). The mechanism of action ofGroup 7 herbicides is the inhibition ofphotosynthesis photosystem II. Fluometuron usage on cotton has decreased almost 90 percent over the years 1998 to 2013. During the time period 2003-2013 , fluometuron annual usage averaged approximately 500,000 pounds active ingredient (a.i

.) on approximately 686 ,000 acres ofcotton, for an average application rate of 0.80 lbs. a.i

. per acre. Fluometuron is used by growers to help manage weed species such as Palmer amaranth that are resistant to glyphosate and to ALS (acetolactate synthase) inhibiting herbicides , especially in the

·Southeast and Mid-south regions in the United States. INTRODUCTION The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an overview ofthe pest management roles and quantitative usage information for fluometuron. The BCP includes summaries ofprevious BEAD products and available public and/or private use and usage data for fluometuron to describe its role in pest management. Additional information on use is available in the fluometuron Label Data Report. Information provided in this BCP may be used by stakeholders (e.g. , users and registrants) , OPP risk assessors , OPP benefit assessors , OPP risk managers , and the general public during the Registration Review process ofthis herbicide. USE SITES Fluometuron is registered for weed control in cotton production. In 2013 , North Carolina was issued a 24(c) label for fluometuron use on wild flower fields to control annual broadleafweeds.

FORMULATIONS AND APPLICATION METHODS Current formulations for fluometuron include a flowable liquid concentrate and an emulsifiable concentrate. Application methods include banded, broadcast, directed spray, and soil incorporated treatment. HISTORY OF FLUOMETURON AND BEAD PRODUCTS A search ofthe BEAD database for previous products for fluometuron indicates that there are no records ofprior benefits assessments or Section 18 Emergency Exemption Requests. Recent Section 18 Emergency Exemption Requests might suggest that a chemical is important for the uses granted in the request; however a lack of Section 18 Emergency Exemption Requests is not an indication ofthe relative importance ofthe chemical.
Page 2USAGE Fluometuron is an herbicide that was registered in the U.S. in 1974

. A re-registration eligibility decision (RED) document was published in 2005. A Screening Level Usage Analysis (SLUA) was prepared by BEAD for fluometuron in 2015 that provides national level poundage applied by active ingredient (a.i.) and percent crop treated (PCT) data. The SLUA shows that an annual average of 500,000 lbs. active ingredient (a.i.) is applied on cotton. This annual average is based on proprietary data and public data that covers the time span from 2004 to 2013

. Based on private market data, fluometuron usage on cotton was about 5 million pounds in 1998. By 2003 usage had declined to about 600 thousand pounds , apparently due to the rapid adoption ofglyphosate-tolerant cotton. This is a drastic decrease in the use of fluometuron on cotton, almost 90 percent decrease. From 2003-2013 , fluometuron annual usage averaged approximately 551 ,000 pounds active ingredient (a.i.) on approximately 686 ,000 acres ofcotton, for an average application rate of0.80 lbs. a.i

. per acre. The overall use offluometuron decreased significantly after 1998 and this is most likely due to the rapid adoption of glyphosate-tolerant cotton (Figures 1 and 2)

. Slight increase of fluometuron use observed around 2011 may be due to the inclusion offluometuron in herbicide resistance management programs (Fig. 2). Figure 

### 1. Fluometuron Usage in Pounds A.I. Ap lied (19 ,28-201_3) 6,000,000

0 N M 'llt Ll"I \I) " co 0\ 0 

## 8 8 8 8 8 8 8 8 

# s N N N N N N N N N Years
Source: Market Research Data, 1998-2013

Page 3**~** N M 

# s s s N N NFigure



### _ 2. Fluometuron Total Area**Treate~ ~I!** **:\. cr** **j_ ~8-~01~** **2** 6,000,000

0 00 en 0 

### .... N rt) "It U"\ ID ,.... 00 en 0 

### .... N t'I')**~ ~**  

### 8 8 8 8 8 8 8 8 

### 8 8 

## s s s .... 0 

# I .... .... N N N N N N N N N N N N N N Years l

- --- - 

### -- Source: Market Research Data, 1998-2013 Geographic Distribution of Fluometuron Use As the following map (Figure 3) shows , Texas , Arkansas and Tennessee are the states with the highest usage offluometuron in terms total area treated which reflects the use on cotton
.

Page4Total Acres Treated**~** NoData 

### CJ < 1 ,000 1,001

- 10,000

.. 10

.001

- 45 ,000

..45

.001 -100,000

..>100,001
Figure 3. Average annual total acres treated of fluometuron (2009-2013). (Source: Market Research Data) The map included herein is for general use in the registration review process. The map provides a very broad geographical view ofthe average annual total acres treated (TAT) with fluometuron over the period from 2009 to 2013. The map units are average annual total acres treated, which accounts for all agricultural acreage treated with this chemical and includes multiple treatments to the same area. The map shows the use offluometuron is mostly in Texas , Arkansas , Tennessee, and to a lesser degree in Missouri, Mississippi and Georgia. Although cotton is produced in Arizona and California, the differences in climate, cotton varieties grown, and the differences in the weed spectrum found in that region may be the factors contributed to the less usage of , fluometuron in that region. The data used to make these maps have many limitations. Any interpretation ofthe maps should consider the underlying data and the associated limitations carefully

. For example, there may be significant differences in the crop acres grown between states and there may be variation in the percent ofeach ofthe various crops treated by the pesticide. TAT is based on private market surveys ofpesticide use in agriculture averaged over the last five years (Market Research Data). These surveys cover about 60 crops and are targeted in states that produce the majority ofthe crop. Although the surveys capture most ofthe use of a particular Page 5active ingredient in agriculture, there are several limitations to these surveys. • States with minor production of a surveyed crop are not sampled • Not all types ofpesticides are surveyed in every crop in every year • Many specialty crops with very small acreages are not included in the survey The result ofthese limitations is that states that show no acres treated may actually have a small amount ofthe active ingredient being used. In some cases , the displayed TAT may be distorted because the surveyed crops and the reported pesticide usage (or TAT) does not accurately represent the actual pesticide usage on the crops produced in the state. The reader should pay particular attention to the figure legends and realize that a map prepared for a particular chemical is not directly comparable to a map prepared for a different chemical as the total acre treatment intervals used in the legend will likely be different. BIOLOGICAL ASPECTS RELEVANT TO FLUOMETURON Fluometuron is a selective and systemic phenyl urea herbicide which belongs WSSA Group 7 (WSSA, 2015). The mechanism of action ofthis herbicide group is inhibition ofphotosynthesis at photosystem II (Herbicide Handbook, 2014). Fluometuron is readily absorbed by roots and translocated ·to the shoots predominantly by xylem. Foliar applied fluometuron is not rapidly absorbed ; it has little or no translocation from the leafto the other parts ofthe plants through phloem tissue. (Herbicide Handbook, 2014). ROLE OF FLUOMETURON IN PEST MANAGEMENT Fluometuron is used to control many annual grasses and broadleafweed species found in cotton production. As described under the usage section, Texas , Tennessee, and Georgia are the states with the highest usage offluometuron during the 2009 to 2013 time frame. Fluometuron provides a wide application window and can be applied as pre-plant, at-plant, preemergence and post-emergence treatments. Application offluometuron is recommended for the control of annual grass weed species such as barnyardgrass (Echinochloa crus-galli), crabgrass (Digitaria sanguinalis), fall panicum (Panicum dichotomiflorum), foxtail spp. (Setaria spp.), goosegrass (Eleusine indica), and broadleaf signalgrass (Brachiariaplatyphylla)

. In addition, fluometuron controls major broadleafweed species , including annual morning-glory (lpomoea sp

p .), cocklebur (Xanthium strumarium), sicklepod (Senna obtusifolia) and Palmer amaranth (Amaranthus palmeri). Other broadleafweeds controlled by fluometuron include Florida pusley ( Richardia scabra), lambsquarters (Chenopodium album), prickly sida (Sida spinosa), common ragweed (Ambrosia artemisiifolia), sesbania (Sesbania e xaltata), Pennsylvania smartweed (Pol ygonumpens y lvanicum) , and spurge (Euphorbia) species

. (Herbicide Handbook, 2014)

. Glyphosate resistant weeds , especially glyphosate-resistant Palmer amaranth (Amaranthus palmeri) are highly problematic for cotton growers in the Southeast and Mid-south regions in the United States (Barnett et al. , 2013). Fluometuron can be tank mixed with other compatible herbicides to increase the efficacy and the range ofweeds controlled. For example, tank-mixing Page 6fluometuron with glufosinate increased the control oflarge Palmer amaranth plants by 28% compared to the glufosinate alone treatment (Barnett et al. , 2013). Also , tank-mixing of fluometuron with treflan is recommended as a pre-plant Incorporated (PPI) treatment to delay the emergence of glyphosate resistant Palmer amaranth in Roundup ready cotton production (Clemson Co-operative Extension, 2012). Fluometuron is also used to control ALS- resistant Palmer amaranth in cotton production (Clemson Co-operative Extension, 2012). Fluometuron use in herbicide resistance management programs may be responsible for the slight increase in usage in recent years. (Fig. 2). Eleven weed species have developed resistance to the mechanism ofaction of group 7 herbicides in the United States (Heap , 2015). The observed decline in the use offluometuron over the 1998-2013 time period may be due to the rapid adoption of glyphosate-tolerant cotton. However, usage offluometuron remained relatively constant after 2003. This relatively consistent usage may be due to the use of fluometuron on non-GMO cotton as well as other niche uses such as use on wild flower fields to control annual broadleafweeds.
DATA NEEDS There are no current BEAD data needs for fluometuron. As the registration review process progresses , certain data needs may arise.

-
REFERENCES: Barnett, K
. A. , Culpepper, A. S. , York, A. C. , and L. E. Stecker. 2013. Palmer Amaranth (Amaranthus Palmeri) Control by Glufosinate plus Fluometuron Applied Postemergence to WideStrike®Cotton. Weed Science Vol 27 , No. 2, pp. 291-297. Biological and Economic Analysis Division (BEAD). 2015. Fluometuron (SLUA) Screening Level Usage Analysis. Office ofPesticide Programs , US Envirorimental Protection Agency. Clemson Cooperative Extension. 2012. Herbicide Programs for Weed Control in Cotton. Online Publication. Available at: https://www.clemson.edu/ extension/ county/hampton/programs/row crops/Cotton/mikem arshall.pdf

. Accessed on September 30, 2015. GMO Compass. 2013. USA: Cultivation of GM plants. Online Publication. Available at:http://www.gmocompass.org/eng/agri biotechnology/gmo planting/506.usa cultivation gm plants 2013 .html. Accessed on Sep. 17, 2015. Heap , I. 2015. The International Survey ofHerbicide Resistant Weeds. Online Publication. Available at: http://www.weedscience.org/summarv/ResistbyActive.aspx

. Accessed on Sep. 17 , 2015. Page 7Herbicide Handbook. 2014. 1 oth edition. Weed Science Society ofAmerica. Fluometuron. 810 E. 10th Street, Lawrence, KS 66044-8897. Pp. 214-215. Market Research Data (MRD). Various years . Data collected and sold by a private market research firm

. Data collected on pesticide use for about 60 crops by annual surveys of agricultural users in the continental United States. Survey methodology provides statistically valid results , typically at the state level. USEPA (United States Environment Protection Agency). 2005. Registration Eligibility Decision for Fluometuron. Available at: http://www.epa.gov/pesticides/reregistration/REDs/fluometuron red.pdf

. Accessed on July 08 , 2015 WSSA, (Weed Science Society ofAmerica). (Undated). Summary ofHerbicide Mechanism of Action. Online Publication

. Available at : http://wssa.net/wp-content/uploads/WSSAMechanism-of-Action.pdf

. Accessed on Sep. 16, 2015.

Page 8