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

## OCT 11 2012 \

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

SUBJECT: 

### BEAD Chemical Profilefor Registration Review: Trifloxysulfuron-sodium (119009) FROM:

THRU: 

### Sunil Ratnayake, Biologist

# ~.....**~ ~**  Biological Analysis Branch (__ 

### '"<..A**~** 

### · SepehrHaddad,EnvironmentalProtectionSpecialist 

# t{

# ~ Science Information and Analysis Branch Stephen Smearman, Economist Economic Analysis Branch Biological andEconomic Analysis Division (7503P) Arnet Jones, Chief 

# ;;J

# ~-)**YY~...-u:...-t:Y"** Biological Analysis

# Branch**~**

# 'l
Diann Sims, Chief Science Information and Analysis Branch Timothy Kiely, Chief

# ~- .. '·

# ~ Economic Analysis Brartch

## ~ 

# J

_**~** Biological andEconomic Analysts Division (7503P) TO: 

### Kelly Ballard,**Ch~mical** 

### ReviewManager RiskManagement and ImplementationBranch 1 Pesticide Re-evaluation Division (7508P) Product Review Panel date: October 3, 2012 INTRODUCTION 

### Thepurpose ofthis document is to conveyusage information and a broad overviewofthepest managementroles ofpesticides that are beginning to undergo registrationreview. The anticipated audience consists ofthe team ofEPA staffcurrently evaluatingthe registration status oftrifloxysulfuron-sodium and eventuallythe general public. This documentbuilds uponthe

### dataprovided in the "Usage and Label Use Data Packages" that are also provided to Registration Reviewteams by BEAD. The document is based on information and data available to BEAD as ofSeptember 26, 2012 Trifloxysulfuron-sodium was first registered inthe United States in 2003. This herbicide belongs to the sulfonylurea family and it inhibits the activity ofacetolactate synthase enzyme which is important for the synthesis ofbranched chain amino acids (leucine, isoleucine, and valine). Trifloxysulfuron-sodium is applied as a tank 

### mixed treatment on fallow seedbeds in the fall and as a post-emergence treatment orpost-directed application to control or suppress a broad spectrum ofweeds including, annual and perennial broadleafweeds, grasses, and sedges in agricultural and non-agricultural sites described below. Similarto other sulfonylurea herbicides, trifloxysulfuron-sodium has a greater activity at very lowrates than many other herbicides and it is rapidly absorbed through the leaves and roots ofsusceptible weed species


### COMMONFORMULATIONS AND APPLICATION METHODS Trifloxysulfuron-sodium is formulated as granular, water dispersible granules and emulsifiable concentrate. 1bisherbicide is applied using ground application equipment and according to the label instructions chemigation and aerial applications are prohibited (Envoke®, Product Label, 2011).


### USE SITES Agricultural Use Sites Trifloxysulfuron-sodium agricultural use sites include citrus, almonds, tomatoes, cotton, and sugarcane. Non-agricultural Use Sites Trifloxysulfuron-sodiumnon-agricultural use sites include ornamental turffor lawns, golf courses, cemeteries, athletic fields, and ornamental turfgrown for sod. 

### USAGE Agricultural Usage Trifloxysulfuron-sodium was registered in 2003. Based onprivate market usage data from 2004- 2011, usage averaged approximately 5,000 pounds active ingredient (a.i.) for 670,000 acres treated. The average a.i. rate overthis time periodwas 0.007 pounds a.i./acre. More recently, in 2011 the average a.i. rate was at a high of0.009pounds a.i./acre. Figure 1presents trifloxysulfuron-sodium usage inpounds a.i. over the 2004-2011 timeframe. Figure 2 presents total area treated in acres overthe 2004-2011**tim~frame.** 

### (Proprietary Data, 2004-2011). Both figures show a sharp increase (almost a doubling in use) between 2010 and 2011.

2

### FIGURE 1. 

### Triflox sulfuron-sodium Usa e in Pounds Active In redient (2004-2011) 10,000 -,-------------- --------

2004 2005 2006 2007 2008 2009 2010 2011 Years 

### Source: Proprietary Data, 2004-2011 FIGURE 2. Triflo sulfuron-sodium TotalArea Treated in Acres 2004-2011) 1,200,000

2004 2005 2006 2007 2008 2009 2010 2011 Years 

### Source: ProprietaryData,2004-2011 Figure 3 shows use oftrifloxysulfuron on cotton and sugarcane. Between 2004 and 2011, approximately 70 percent oftotal use has been on cotton withthe remaining 30 percent on sugarcane. Between 2010 and 2011 pounds a.i. applied more than doubled on cotton and sugarcane, while total areatreated 

### inacres for both crops also doubled.

3

### FIGURE 3. Use ofTrifloxysulfuron-sodium- Percent ofTotalLbs. Applied on Cotton and Su arcane 2004-2011

Source: ProprietaryData, 2004-2011 FIGURE 4. Stateswith Highest Use ofTrifloxysulfuron-sodium- Percent ofTotalLbs. A lied 2004-2011

6% MISSISSIPPI 7%

8%

10% 

### Source: ProprietaryData, 2004-2011 The states withthe highest use interms ofpercent oftotal pounds a.i. applied are Florida (27%) followed by North Carolina (14%), Georgia (13%), Louisiana (10%), Arkansas (8%), Mississippi (7%), and Texas (6%) as shown in Figure 4. The "other" states shown in Figure 4 accounting for 15 percent oftotaluse include Alabama, Tennessee, South Carolina, Missouri, California, Virginia, Kansas, and Oklahoma. Sugarcane is grownprimarily in Florida and Louisiana. Its use on cotton is more widespread. Cotton is grown in Arkansas, Georgia. Louisiana, Mississippi, North Carolina, and Texas.
4

### Agricultural Usage by Crop Reporting District Another measure ofusage is the use intensity. Inthis analysis, the use intensityis expressed as the pounds a.i. applied per acre ofland in farms. This differs from the applicationrate, which is expressed as the pounds a.i. applied pertreated area. Figure 5 spatiallyrepresents trifloxysulfuron-sodium usage by crop reporting district for 2006- 2010. The area depicted inred onthe map (in Louisiana), is due to the higher applicationrate of this active ingredient on sugarcane as opposed to cotton.


### FIGURE 5. Trifloxysulfuron-sodium Usage by Crop Reporting District 

### (2006- 2010)

Average Pounds Per 1,000 Acres of Farmland

- <0.02 0

.02-0

.04 

## D o.o5-o

.o8 0

.09-0

.27 0.28-0.45

This is a map ofagricultUral pesticide usage at the Crop Reporting District (CRD) level prepared by BEAD for use in the Environmental Fate and Effects Division documents. These maps are used to help visualize where the pesticide being considered is most likely to be used and can be helpful in scenario selection and placing the exposure assessment in context. CRDs are boundaries created by USDA NASS which are aggregates ofcounties (USDA, 2010). Pesticide usage is displayed as average pounds (for the years 2006- 2010) per 1,000 acres of farmland in a CRD to normalize for the variation in farmland between CRDs. Farmland acreage was obtained from USDA (2007)

. Farmland or "land in farms" is defined as follows: The acreage designated as "land in farms" consists primarily ofagricultural land used for crops, pasture, or grazing. It also includes woodland and wasteland not 5actually under cultivation or used for pasture or grazing, provided it was part of the farm operator's total operation. Large acreages of woodland or wasteland held for nonagricultural purposes were deleted from individual reports during the edit process. Land in farms includes CRP, WRP, FWP, and CREP acres. Land in farms is an operating unit concept and includes land owned and operated as well as land rented from others. Land used rent free was reported as land rented from others. All grazing land, except land used under government permits on a per-head basis, was included as "land in farms" provided it was part ofa farm or ranch. Land under the exclusive use ofa grazing association was reported by the grazing association and included as land in farms. All land in American Indian reservations used for growing crops, grazing livestock, or the potential of grazing livestock was included as land in farms. Land in reservations not reported by reservation, individual American Indians or nonNative Americans w_as reported in the name ofthe cooperative group that used the land. In many instances, an entire American Indian reservation was reported as one farm (2007 Census ofAgriculture, USDA). Usage is based on private market surveys ofpesticide use in agriculture (Proprietary Data, 2006-2010). The survey data are limited to the states that represent the top 80-90% of acreage for the individual crops, therefore, use may be occurring in regions outside the scope of the survey. CRDs showing no usage of pesticides may be due to either the lack ofpesticide use in the region or non-participation in the agricultural surveys. In addition, across the years, there may be variations in the specific crops included in the CRD survey. This may result in a lower annual average for the CRD. This map displays ratio data (i.e., average pounds per 1,000 acres offarmland) summarized at a very highlevel. Readers are strongly cautioned against trying to over interpret the map without examination of the underlying data. The underlying data may explain some ofthe many reasons that a Crop Reporting District may have a high value for a particular active ingredient such as significant acreage (compared with the CRD as a whole) ofa crop or crops with a high applicationrate and frequency ofapplication. 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. Scale and units of measurement do matter and may be different between maps. Sources: Proprietary Data. 2006-2010. USDA, 2006-2010. NASS Crop Reporting Districts. USDA, 2007. Census ofAgriculture. Non-Agricultural Usage In terms ofnon-agricultural usage, data are available only for golfcourses for 2004 and 2006 and landscape for 2004 as shown in Table 1below. It is importantto note thatthis data is dated but is presented in this document for reference. 

### Table 

### 1. Trifloxysulfuron-sodium SelectNon-AgriculturalUsage (Pounds A.I.) (2004-2006) Site 2004 2006 GolfCourses 450 125

Landscape 30 

### NIA N/A=not available Source: Kline 

### & Co., 2004, and 2006 

### 6

### BIOLOGICAL ASPECTS RELEVANTTO TRIFLOXYSULFURON-SODIUM Trifloxysulfuron-sodium is a sulfonylurea herbicide and the mode ofaction ofthis class ofherbicide is inhibition ofacetolactate synthase (ALS) enzyme. According to the Weed Science Society of America (WSSA) mode ofaction classification, this herbicide is included in the group ofB/2 herbicide site ofaction. Itwas reported that 127 weed species have developed resistance to the herbicides with

. this mode ofaction (Weedscience.org, 2012). Trifloxysulfuron-sodium is a systemic herbicide highly effective in controlling broad spectrum ofbroadleaf, sedges, and grass weeds ata very low rate compared to other herbicides and it is widely used to control or suppress troublesome weeds such as morning-glory (Ipomoea spp.), sicklepod (Cassia obtusifolia), hemp sesbania (Sesbania exaltata), pigweed (Amaranthus spp.), nutsedge (Cyperus species), barnyardgrass (Echinochloa crus-galli), and Johnsongrass (Sorghum halepense) in cotton, sugarcane, and tomato production (Envoke®, Product Label, 2011). Based on the usage information shown in Figure 2, the acreage treated with trifloxysulfuron has increased significantly from 2010 to 2011. The increase in number ofpounds applied and the number ofacres treated with this herbicide could be due to the spread oftroublesome weeds such as glyphosate resistant Palmer amaranth found in cotton fields (Hollis, 20 12). 

### HISTORY OF BEAD ASSESSMENTS FORTRIFLOXYSULFURON-SODIUM A search ofthe BEAD Official Records database and the Section 18 database did not find any assessments or Section 18 requests specifically for trifloxysulfuron-sodium.



### INFORMATION THAT MAY BE USEFUL FORBEAD'S FUTURE WORK ON TRIFLOXYSULFURON-SODIUM Any available information on non-agricultural uses such as targetpests, rates, and areatreated would be useful. 

### CONCLUSION Trifloxysulfuron-sodium's use oncotton and sugar cane significantly increased from 2010 to 2011. 

### It remains to be seen whetherthis was a one year fluctuation due to increasedpest pressure, resistance orotherenvironmental factors without future use data. 

### It is clearthat trifloxysulfuron-sodium has become a valuable tool for growers to control, morningglory, nutsedge, sicklepod, Johnsongrass, barnyardgrass, and Palmer amaranth species in cotton and sugarcane production.

7

### REFERENCES Crop Management. 2012. SyngentaDevelops Herbicide to Control Key Broadleaf, Weeds, Sedges, Grasses in Cotton, Sugarcane, Citrus, and Tomatoes. http://www.plantmanagementnetwork.org/pub/cm/news/envoke/

. Accessed on September 14, 2012. Envoke®, Product Label, 2011. Syngenta Crop Protection, LLC. Greensboro, North Carolina 27419. http://www.syngentacropprotection.com/pdf/labels/SCP1132AL1 E121O.pdf. Accessed on September 6, 2012. Hollis, P. 2012. Glyphosate-resistant pigweed in a class all alone among cottonpests. Southeast Farm Press. http:/ /southeastfarmpress.com/cotton/glyphosate-resistant-pigweed-class-all-aloneamong-cotton-pests-0. Accessed on September 13, 2012.
Kline & Co., 2004, and 2006. Proprietary Data, 2004-2011. USDA, 2006-2010. NASS Crop Reporting Districts. Online: http://www.ers.usda.gov/briefing/arms/resourceregions/resourceregions.htm#nass

. Accessed on September 6, 2012. USDA, 2007. Census ofAgriculture. Online: http://www.agcensus.usda.gov/Publications/2007/index.asp

. Accessed on September 7, 2012. Weedscience.org. 2012. Herbicide Resistant Weeds. http://www.weedscience.org/summary/MOASummary.asp Accessed on September 18, 2012.



### 8