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

## APR 

## 2320#.3

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

SUBJECT: Responses to Public Comments Submitted by Syngenta Crop Protection, LLC. Concerning the Registration Review ofClodinafop-propargyl (PC Code 125203) from EPA Docket ID No

. : EPA-HQ-OPP-2012-0424, DP# 409739

FROM:

THRU: .

# T~~**~--J+-.~** Jihad Alsadek, PhD, Economist "' Science Information and Analysis Branch
Bill Phillips, PhD, Agronomist 

## AI j _,/ Biological Analysis Branch

## ~ Stephen Smearman, Economist Economic Analysis Branch Biological and Economic Analysis Division (7503P)
Diann Sims, Chief

# /()~ Science Information and Analysis Branch
Arnet Jones, Chief ;/)

# ~~~ Biological Analysis 

### Branch

# ~I'

# u . Timothy Kiely, Chief 

# Sl \A.,

# ~ Economic Analysis Branch Biological and Economic Analysis ivision (75
TO: Wilhelmena Livingston, Chemical Review Manager Risk Management and Implementation Branch4 Pesticide Re-evaluation Division (7508P) Product Review Panel Date: April3, 2013 Through this memo, BEAD i

. sresponding to comments submitted by Syngenta Crop Protection, LLC concerning the registration review ofClodinafop-propargyl. In addition to this response, BEAD is providing a revised version ofthe BEAD Chemical Profile for Clodinafop-propargyl (November 2012) which addresses several ofthe Syngenta comments.

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### Syngenta Comment 1: Syngenta believes thepercent crop treated for wheatshouldbe 

### 7.

### 4%for average and 15.1% for maximum. BEAD Response: The**Percen~** Crop Treated (PCT) values (5% for the average and 10% for the maximum) reflect the results ofthe Screening Level usage Analysis (SLUA) for clodinafoppropargyl. These values are derived from several pesticide usage data sources (USDA/NASS and EPA Proprietary Usage Data). These data are merged, averaged, and rounded for reporting purposes. We are not clear on the method used by Syngentato derive the PCTvalues or the time frame represented intheir data. No changes are suggested for the BEAD values

. 

### Syngenta Comment2: Syngenta believes that the agricultural usage averagedapproximately 7

4, 000pounds active ingredient (lbs. a. i.) on 6 million treatedacres. BEAD Response: We are not clear onthe data sources used to derive the Syngenta results and cannot confirm them. BEAD'sreported values are based onproprietary data. Based onthat data, the average annual pounds active ingredient (74,000 lbs. a.i.), and the average annual total area treated (1.8 million acres) are correct for the time period 2006-2010. No changes to BEAD values are suggested.


### Syngenta Comment3: Syngenta respectfully submits that winter wheat accounted for 14% and springwheat accounted for 76% of the wheatproduced in Idaho, Montana andNorth Dakota. BEAD Response: BEAD ha.S removed this sentence inthe BCP as it was confusing and did not provide additional supporting information to the fact that the majority ofthe durum wheat in the U.S. was harvested inthe two states ofNorth Dakota and Montana. Overall, two sentences were removed because they were**c~nfusing** and did nothing to add to the focus ofthe paragraph. Original paragraph: Clodinafop-propargyl is primarily used inthe northern wheat production areas ofthe country, concentrated mostly inthe states ofIdaho, Montana andNorth Dakota. The types ofwheat produced in these states are durum wheat, hard red spring and winter wheat, and soft white spring and winter wheat. For the years 2006-2010, winter wheat accounted for an average of 10% and spring wheat accounted for 72% ofthe wheat produced in Idaho, Montana andNorth Dakota. During this same time period, less than 5% ofall wheat planted inthe country included one ofthe spring wheat types such as durum. 70% ofthe durum wheat was planted inNorth Dakotawith a smaller amount in Montana (20%)

. 

### In 2010 and 2011, the average number of acres ofdurum wheat harvested by farmers inthe states ofMontana and North Dakotatotaled 89% ofthe nation's durum wheat grain harvest.
Revised paragraph: Clodinafop-propargyl is primarily used inthe northern wheatproduction areas ofthe country, concentrated mostly in the states ofIdaho, Montana and North Dakota. The types ofwheat produced inthese states are durum wheat, hard red spring and winter wheat, and soft white spring and winter wheat. Seventy percent ofthe durum wheat was planted inNorth Dakota with a smaller amount 

### inMontana(20%). In 2010 and 2011, the average number ofacres ofdurum wheat harvested by farmers in the states ofMontana and North Dakotatotaled 89% ofthe nation's durum wheat grain harvest.


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### Syngenta Comment4: Syngenta respectfully submits that c/odinafop-propargyl was appliedto 93% of the total acres treated (FAT) while 9% of the lbs. a.i. hadbeen appliedto 7% of the different types of winter wheat.

. . 

### BEAD Response: BEAD agrees to this revision and has changed the percentages inthe revised version ofthe BCP. The difference was due to rounding error in the BEAD calculation.


### Syngenta Comment5: Syngenta would like to respectfully revise foliar to foliar, postemergence. 

### BEAD Response: BEAD agrees to this revision. Clodinafop-propargyl is a systemic, postemergence herbicide for selected grass control in spring and durum wheat. These changes are addressed in the revised BEAD Chemical Profile for Clodinafop-propargyl (March 26, 2013). 

### Syngenta Comment 6: The maximum application rate for Discover Herbicide (EPA Reg. No. 100-907) is 4jloz/A, andthe active ingredient (a.i.) maximum application rate for Discover Herbicide (EPA Reg. No. 100-907) is 0. 0625 lb/A. 

### BEAD Response: BEAD agrees that the Discover herbicide label does show that 4 fluid ounces per acre is the labeled maximum application rate for this product in a minimum of5

### gallons of water or aerially in a minimwn of3 gallons ofwaterper acre combined with 12.8 ounces ofDSV adjuvant. The dosage conversion system 

### in BEAD's label use reports does not provide converted active ingredient (a.i.) rates for 

### tank mixes including surfactant and adjuvant mixtures. As such, the maximum converted rate for this product was captured as No Dosage Conversion (NDC) 

### in the converted single maximum application fields ofthe Clodinafop-propargyl Appendix A and EFED Label Data report. BEAD agrees with Syngentathat the converted single maximum application rate is 0.0625 lb. a.i. /A.

Sources: Clodinafop-propargyl Screening Level Usage Analysis (SLUA), EPA-HQ-OPP-2012-0424-0004 Appendix A, EFED Label Datareport B. Phillips, J. 

### Alsadek, and S. Smeannan Clodinafop-propargyl BCP, March 26, 2013 Syngenta Crop Protection, LLC. Comments Submitted by Syngenta Crop Protection, LLC. Concerning the Registration Review ofClodinafop-propargyl (PC Code 125203) from EPA Docket ID No.: EPA-HQ-OPP-21012-0424, February 8, 2013 B. Phillips, J. Alsadek, and S. Smeannan. Responses to Public Comments Submitted by Syngenta Crop Protection, LLC. Concerning the Registration Review ofClodinafop-propargyl (PC Code 125203) from EPA Docket ID No.: EPA-HQ-OPP-21012-0424

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