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

## MAR 112015 ' OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION MEMORANDUM SUBJECT: FROM:

THRU: BEAD Chemical Profile (BCP) for Registration Review ofPinoxaden (147500) Sunil Ratnayake, Ph.D., Biologist

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_ Biological Analysis Branch

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# 4**~** Jihad Alsadek, Ph.D., Economist 

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# ~ Science Information and Analysis Branch Derek Berwald, Ph.D., Economist

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Diann Sims, Chief**~rttl"-l~u,/1 144** **-.v** Science Information and Analysis Branch Timothy Kiely, Chief

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Economic Analysis Branch Biological and Economic Analys· Division ( 50 ) TO: Miguel Zavala, Chemical Review Manager Risk Management and Implementation Branch 3 Pesticide Re-evaluation Division (7508P)
Peer Review Panel Date: February 18, 2015

### SUMMARY Pinoxaden was first registered in the United States in2005 (USEPA, 2005). This selective and systemic herbicide belongs to the phenylpyrazolin family. Pinoxaden is applied as a postemergence treatment for the control ofannual grass weeds and certainbroad leafweeds in barley, winter wheat, and spring wheat, including durum. Pinoxaden can be tank mixed with compatible herbicides to broaden the weed control spectrum in small grain production. Based onprivate marketusage data from 2006-2012, usage ofthis herbicide averaged approximately 165,000 pounds active ingredient (a.i.) applied annually on approximately 3,685,000 acres treated
. The average a.i. rate over this time period is 0.045 pounds a.i. /acre. There are no reported usage data for non-agricultural use sites. Onthe basis of2008 to 2012 proprietary data, on average the highestusage (pounds a.i. applied) ofthis herbicide was observed inNorth Dakota
. According to the available usage data interms ofpercent ofcrop treated, 30 percent ofbarley and 5 percent ofwheat are treated with pinoxaden. INTRODUCTION The Biological and Economic Analysis Division (BEAD) Profile (BCP) provides an overview of the pest management roles and quantitative usage information for pinoxaden. The BCP includes summaries ofprevious BEAD products and available public and/orprivate use and usage data for pinoxadento describe its role inpest management. Additional information onuse is available in the pinoxaden LUIS Label Data Report. Information provided in this BCP may be used by stakeholders (e
.g., users and registrants), OPP risk assessors, OPP risk managers, and the general public during the Registration Review process ofthis pesticide. USE SITES Agricultural Use Sites Pinoxaden registered agricultural use sites include: barley, spring wheat, and winter wheat.
FORMULATIONS AND APPLICATION METHODS Pinoxaden is formulated as an emulsifiable concentrate, flowable concentrate and soluble concentrate/liquid. Pinoxaden is applied post emergence for control ofgrass weeds in wheat (including durum) and barley. Pinoxaden is applied once per crop season using ground and aerial application equipment.
HISTORY OF PINOXADEN and BEAD PRODUCTS Pinoxadenis an herbicide registered for use in the U.S. since 2005. A Screening Level Usage Analysis (SLUA) was prepared by BEAD for pinoxaden in 2014 that provides national level poundage applied by active ingredient (a.i.) and percent crop treated (PCT) data for crops for Page2whichusage data are available. Forpinoxaden, the agricultural sites withthe highest average lbs. a.i. used annually were wheat (100,000 lbs. a.i
.) followed bybarley (40,000 lbs. a.i.). In terms ofthe percent crop treated, barley is 30 percenttreated and wheat is 5 percenttreated with pinoxaden. The high percent crop treated for barley may indicate highbenefits for this crop, or atthe very least, a high reliance onpinoxaden to control weeds inbarley. A search ofthe BEAD database for previous BEAD products for pinoxaden indicates that BEAD has not evaluatedpinoxaden since early in its registration, when reviews onthe efficacy ofpinoxaden against barnyard grass were made to supportthe addition ofbarnyard grass to the U.S. label. 

### USAGE Agricultural Usage Based onprivate market usage data from 2006-2012, usage averaged approximately 165,000 pounds active ingredient (a.i.) applied annually on approximately 3,685,000 acres treated. The average a.i. rate over this time period is 0.045 pounds a.i. /acre. Figure 1presents pinoxaden usage in pounds a.i. overthe 2006-2012 timeframe. Figure 2 presents total area treated in acres overthe same time period. The data showthatthe use ofpinoxaden increased significantly between 2006 and 2008 and was stable thereafter. (Proprietary Data, 2006-2012). 

### Figure 1. 

### Pinoxaden Usage in Pounds Active Ingredient (2006-2012) 250,000

""O**-~** 0.. a. c:i:: <i. Ill ""O c: :l 0 c...
0 \0 ..... 00 (1\ 0 .-4 N 0 0 0 

### 8 .-4 0 0 0 0 .-4 .-4 0 0 N N N N N N N Years
Source: Proprietary Data, 2006-2012

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### Figure 2. Pinoxaden Total Area Treated in Acres (2006-2012) 5,000,000

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0 u:> 0 0 N r-. 0 0 N

Source: ProprietaryData, 2006-2012 00 0 0 N Years 

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...... 0 N ......
...... 0 N N

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The major agricultural use ofpinoxaden during the 2008-2012 time frame was on wheat (spring and winter) and barley in North Dakota, Montana and Idaho. Tables 1 and 2 showthe crops and states where pinoxaden is applied. Most ofthe use (77 percent ofpinoxaden use) is in wheat, with the majority ofthat use in spring wheat. Most ofthe pinoxaden use is in states with significant acreage ofwheat and barley, as shown in Table 2. Although more ofthe use is on wheat, pinoxaden may be more important onbarley, where a larger portion ofthe much smaller crop is treated, as mentioned above. Wheat acreage is·substantially larger than barley acreage, which is why the majority ofuse is on wheat, even though more ofthe barley crop is treated.

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### in Terms ofPounds A lied 2008

- 2012 

### Percent ofTotal Pounds A lied 62 23 Winter Wheat 15 

### Source: ProprietaryData, 2008-2012


### Table 2. 

### Share ofPinoxaden Use by State in Terms ofPounds Applied (2008

- 2012) 

### State Percent ofTotal Pounds Aoolied North Dakota 45 Montana 24 Idaho 

### 10 Other* 21 

### Source: Proprietary Data, 2008-2012 *Other states includes Minnesota, Tennessee, Washington, Texas, Arkansas, Oklahoma, Colorado, North Carolina, Kentucky, South Dakota, Wyoming, Missouri, Virginia, Nebraska, Oregon, Kansas, California, Utah, Georgia, Michigan and Pennsylvania
. Application Rates The average a.i. rate for the top crops in terms ofaverage annual pounds a.i. applied was highest on wheat both spring and winter at 0.05 lbs. a.i. per acre and lowest for barley at 0.04 lbs. a.i. per acre, as shown in Table 3.


### T bl 3 

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a e . moxad 

# u en se on T C 

### op rops andA verage A I R 

### t 2008 2012 

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# - Average Annual Average AnnualTotal Crop Pounds AI Area Treated * 

### Applied Barley 46,000 1,037,000 Wheat, Spring 123,000 2,725,000 Wheat, Winter 29,000 62·1,000 *Total Acres Treated swns all acre treatments for a crop. 

### Source: Proprietary Data, 2008-2012 Geographic Distribution ofPinoxaden Use 

### AI Rate (lbs AI/acres) 0.04 0.05 0.05

Figure 3 provides a very broad geographical view ofthe average annual amount (in pounds) of pinoxaden applied per 1,000 acres ofcrop acres grown. The calculated values presented in the map are not equivalent to an application rate (lbs
. a.i./a), therefore, the map may show areas of high use intensity that do not necessarily correspond to the states listed in Table 2 since those are the states with the highest use ofpinoxaden based onpounds active ingredient applied
. However, in this case, the map does demonstrate thatNorth Dakota and Montanawhich account for 69 percent ofpinoxadenusage in terms ofpounds a.i. applied are also the states withthe Page 5highest use intensity. As shown in the map, these states depict a high use intensity ofacres treated with pinoxaden. Please see Appendix A for a more detailed explanation ofthe information presented on the map. 

### Figure 3. Annual average agricultural use intensity ofPinoxaden (2009-2013).

PoundsActive Ingredient per 1,000 Crop Acres Grown 

## c:::J No Data LJ <0.05 CJ o.05

- 0
.1 0.1

- 0
.5

. 0.5-1 

# ->1

(Source: ProprietaryData)

Page 6BIOLOGICAL ASPECTS RELEVANT TO PENOXADEN Pinoxaden belongs to the phenylpyrazolin family ofherbicides (Group 1). This is a selective and systemic herbicide used as a post-emergence treatment and it controls economically important annual grass weed species and certain broadleafweeds in barley and wheat production. Pinoxaden is rapidly absorbed by the weed foliage and translocated to the growing points. The mechanism ofaction ofthis herbicide is inhibition ofAcetyl CoA Carboxylase enzyme (ACCase) (WSSA, Undated). This enzyme interferes with the synthesis ofmembrane lipids. Susceptible weed species generally stop growing within a few days afterthe application. Leaf chlorosis and necrosis develop within 1to 3 weeks after the treatment and weeds are completely controlled within five weeks (Herbicide Handbook, 2014).
ROLE OF PINOXADEN IN PEST MANAGEMENT Pinoxaden is an important herbicide available for weed control in barley, winter wheat, and spring wheat including durum. Pinoxadenhas an excellent crop safety and controls many troublesome grass weeds such as: wild oat 

### (Avenafatua), volunteer oat 

### (Avena sativa), green foxtail 

### (Setaria viridis), yellow foxtail 

### (Setaria glauca), giant foxtail 

### (Setariafaberi), Italian ryegrass 

### (Lolium multiflorum), Persian darnel 

### (Loliumpersicum), barnyard grass 

### (Echinochloa crus-galli), Canarygrass 

### (Phalaris spp.), wild proso millet 

### (Panicum miliaceum), and wind grass 

### (Apera spp.) (Axial XL® Product Label, 2014). In addition, pinoxaden can be tank mixed with other compatible herbicides to increase the weed control spectrum in barley and wheat production (Axial XL® Product Label. 2014). Tank mixing ofpinoxaden with otherherbicides with different modes ofaction helps on minimizing the development ofherbicide resistance weeds in wheat and barley production. As described under the usage section, the percent ofcrop treated with pinoxaden for barley and wheat were 30 percent and 5 percent, respectively. Pinoxaden effectively eradicate major classes ofgrass weeds, leading to a substantial increase in crop yield. Grassy weeds including wild oat, cheatgrass, green foxtail, and Persian darnel are among the most serious weed problems to many barley growers (Univ. ofMontana, Undated). Control ofthese weeds may contribute to the relatively highpresent ofbarleytreated with pinoxaden. According to the international survey ofherbicide resistant weeds in the United States 15 weed species have developed resistance to the Group 1 herbicides. However, presence ofonly 2 weeds species; Italian ryegrass 

### (Loliumperenne ssp. multiflorum, and green foxtail 

### (Setaria viridis) with resistance to pinoxadenhave beenreported in the. United States (Heap, Undated).

Page7DATA NEEDS Currently, no data need is observed for this chemical. · APPENDIX A The map included herein primarily for the use ofthe risk assessors in the Environmental Fate and Effects Division. The map provides a very broad geographical view ofthe amount (inpounds) ofthe active ingredient applied per 1,000 acres of"land in farms"
. These data are included in the maps because risk assessors are interested in the amount ofa pesticide used across farmland. Because ofthe definition ofLand in Farms, as discussed below, the calculated values presented in the map are 

### not equivalent to an application rate (lbs air. /A). The data used to make these maps have many limitations. Any interpretation ofthe maps should considerthe underlying data and the associated limitations carefully. The smallest areas shown onthe maps within each state are Crop Reporting Districts (CRD). CRDs are defined byUSDA and each consists ofmultiple counties that have similar soils, growing conditions, and farming practices. The CRDs within many states have roughly the same area. Because it is not feasible to conduct an agricultural survey that samples every county in the United States, the use ofCRDs allow for a sample to be collected thatrepresent a much larger area with relatively homogeneous agricultural characteristics. The numerator (annual average pounds applied) is based onprivate market surveys ofpesticide use in agriculture averaged overthe last five years (Proprietary Data, 2008-2012). These surveys cover about 60 crops and are targeted in states that producethe majority ofthe crop. Although the surveys capture most ofthe use ofa particular active ingredient in agriculture, there are several limitations to these surveys.
• States with minor production ofa 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 CRDs that show no usage may actually have a small amount ofthe active ingredientbeing used
.

Page 8 ·The denominator (1,000 Acres ofland infarms) was selected from the Census ofAgriculture (USDA, 2007) to represent agricultural acreage that is actively managed and includes most ofthe lireas treated with pesticides. The category "Land inFarms" is defined by the Census of Agriculture as being made up offour components: • Total cropland • Permanentpasture • Total woodland • Land in farmsteads, buildings, livestock facilities, ponds, roads, wasteland, etc. This category includes land in the various USDA conservationprograms. It shouldbe noted that the Census ofAgriculture does not include grazing land rented (on a per-animal basis) from the Bureau ofLand Management or Forest Service, thus 

### itis anunderestimate ofthe land being managed for agricultural purposes. The reader should pay particular attention to the figure legends and realize that a map prepared for a particularpinoxaden is not directly comparable to a map prepared for a different pinoxaden. Scale and units ofmeasurement do matter and may be different between maps.
REFERENCES Axial XL® Product Label. 2014. Syngenta Crop Protection LLC. P. 

### 0. Box 10300, North Carolina, 27419. Online Publication. Available at: http://www.cdms.net/LDat/ld9M9000.pdf
. Accessed on Feb. 13, 2015. BEAD, 2014. Pinoxaden Screening Level Usage Analysis. Biological and Economic Analysis Division, Office ofPesticide Programs, US Enyironmental Protection Agency. November 17, 2014. Heap, I. (Undated).The International Survey ofHerbicide Resistant Weeds. Online Publication. Available at: http://www.weedscience.org/summary/ResistbyActive.aspx
. Accessed on January 28, 2015. Herbicide Handbook. 2014. 10th edition. Weed Science Society ofAmerica. Pinoxaden. Pp 355-356
. 810 E. 10th Street, Lawrence, KS 66044-8897. Montana State University. (Undated). Montana Barley Production Guidelines. Online Publication. Available at: http://www.msuextension.org/carbon/Documents/ag%20barley%20prod.pdf
. Accessed on Feb. 27, 2015. Proprietary Data, 2006-2012. USDA- NASS, 2004. Available at: http://www.nass.usda.gov/Statistics by Subject /index.php?sectoi=CROPS
. Accessed on February 20, 2015. Page9USEPA. 2005. Pinoxaden Conditional Registration. Available at: http://www.epa.gov/oppOOOOI/chem search/reg actions/registration/fs PC-147500 0lJul-05.pdf. Accessed onJanuary 28, 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 onJanuary 28, 2015.

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