UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

"WASHINGTON, D.C. 20460 

OCT 19 2015 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Prothioconazole 

(113961) 

FROM: Carl Chen, Biologist 

Claire Paisley-Jones, Biologist l-~t"'-, ,,, . . ~ Science Information and Analysis Branch I 

Andrew Lee, Economist tJ..L C k, Economic Analysis.Branch f 

Biological and Economic Analysis Division (7503P) 

THRU: Arnet Jones, Chief 

Biological Aiialysis B 

Diann Sims, Chief~ . rJ. J._,itvJ...-

Science Information and An ysis Branch 

Timothy Kiely, Chief f'>r-- \μ\_~ Economic Analysis Branchu J 

Biological and Economic Analysis Divisi 03P) 

TO: Margaret Hathaway, Chemical Review Manager 

Risk Management and Implementation Branch 2 

Pesticide Re-evalua#on Division (7508P) 

Product Review Panel date: September 9, 2015 

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SUMMARY 

Prothioconazole is currently the sole fungicide in triazolinthiones, which was added in 2012 to 

the Group 3 ofDMI (DeMethylation Inhibitor) fungicides classified by the Fungicide Resistance 

Action Committee. It has b~en used to control or suppress some important crop diseases such as 

anthracnose leaf blight on com, Ascochyta blight on dry beans/peas, white mold on peanuts, frog 

eye leaf spot on soybeans, Rhizoctonia solani on sugar beets, and Fusarium head blight (scab) on 

wheat. Prothioconazole is also registered for use on nursery stock such as nursery seedlings of 

loblolly pine to control pitch canker and other diseases. The agricultural use of prothioconazole 

in the United States has been incre~sing since its registration in 2007, treating a total of 

approximately 11,000,000 acres in 2013 for all crops combined. 

INTRODUCTION 

The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an 

overview of the pest management roles and quantitative usage information for prothioconazole. 

The BCP includes summaries of previous BEAD products and available public and/or private 

use and usage data for prothioconazole to describe the role of this chemical in pest management. 

Additional information on use is available in the prothioconazole Label Data Reports. 

Information provided in this BCP may be used by stakeholders (e.g., users and registrants), OPP 

risk and benefit assessors, OPP risk managers, and the general public during the Registration 

Review process of this pesticide. 

HISTORY OF PROTHIOCONAZOLE AND BEAD PRODUCTS 

There are no benefits assessment or review of recent Section 18 emergency exemption requests 

by BEAD for this chemical. An emergency exemption may indicate that there is a need for a 

particular chemical that is not registered for use on a particular site. An emergency exemption 

request may yield information about a particular chemical's importance or value that is not found 

in other EPA records. However, a lack of Section 18 assessments by BEAD does not 

specifically indicate the relative importance of the chemical. 

A recent BEAD work that might be of relevance is noted below. 

In May 2015, BEAD reviewed and concluded that the criteria have been met by the nine minor 

uses (listed below) to extend the exclusive use period for the maximum three years allowed by 

the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). When pesticides are 

registered, the original data submitter has a 10-year exclusive use period from the date of 

registration for the data submitted in support of the original registration. FIFRA allows for an 

extension of that exclusive use period if certain criteria are met. An extension of one year is 

provided for every three qualifying minor uses, for a maximum of three years. Bayer submitted 

a petition to EPA requesting that, under FIFRA Section 3(c)(l )(F)(ii), the exclusive use period 

be extended for three years with supporting information on 17 crops. BEAD reviewed nine 

crops and found that the use of prothioconazole on buckwheat, cantaloupe, chickpea, cucumber, 

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loblolly pine (nursery), lowbush blueberry, popcorn, summer squash, and watermelon met at 

least one of the criteria for extension of the exclusive use period: that is, 

prothioconazole plays a significant part in integrated pest management or resistance management 

or there are insufficient efficacious alternative registered fungicides available. 

USE SITES 

Agricultural Use Sites 

Prothioconazole is registered for use on alfalfa, beans, bushberries, rice, corn, small grains, 

crambe, cucurbits, mustard, peanuts, peas, potatoes, small fruit, sugar beets, soypeans, and 

nursery stock (for specific sites, see the Label Data Report). 

Non-Agricultural Use Sites 

Prothioconazole is not registered for use on any non-agricultural sites. 

FORMULATIONS 

Prothioconazole is formulated as a liquid soluble concentrate, emulsifiable concentrate, and 

flowable concentrate. 

APPLICATION METHODS 

Prothioconazole is applied using broadcast, banded, chemigation, and seed treatment methods. 

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USAGE 

Agricultural Usage 

Since it was first registered in 2007, usage of prothioconazole has increased steadily. In 

2013, nearly 500,000 pounds were applied to nearly 11,000,000 acres (Figure 1). 

11,000,000 500,000 

"C 

Q) 

..... <t ro 

Q) II) 

... "C I- c: ro ::J Q) 0 ... c... <( 

~ ..... 

0 

I0 0 

2007 2008 . 2009 2010 2011 2012 2013 

- Total Area Treated - Pounds Al 

Figure 1. Prothioconazole Total Acres Treated and Total Pounds A.I. Applied (2007-2013). 

Source: Proprietary Data, 1998-2013 

The vast majority of prothioconazole is used to treat wheat, nearly 50 percent of total pounds 

applied or approximately 140,000 ibs. A.I. per year. The remaining 50 percent of 

prothioconazole, is used on nine other crops, including peanuts, sugar beets, and com (Table 1 ). 

While soybeans account for·only seven percent of pounds A.I. applied annually, they account for 

over a quarter of the total acres treated per year, due to the low rate at which prothioconazole is 

applied to soy as a seed treatment (Table 1). While sugar beets and peanuts account for a small 

portion of pounds applied and total acres treated, a relatively large percent of these crops are 

treated with prothioconazole. According to the most recent SLUA covering the years 2009-2013, 

an average of 15 percent (maximum 30 percent) of sugar beets are treated, and an average of 15 

percent (maximum 20 percent) of peanuts are treated annually (BEAD 2015). It should be noted 

that the data presented in this section may be an underestimate of actual usage, as not all seed 

treatment uses may be capttired. 

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\ 

T bl 1 P th" l u I T C I I 2009 2013 -

!Spring Wheat 5 30 88,000 1,090,000 0.080 

!Winter Wheat < 2.5 18 52,000 703,000 0.074 

!Peanuts 15 13 39,000 432,000 0.090 

ISugar Beets 15 12 . 36,000 211 ,000 0.169 

Com < 2.5 10 30,000 963,000 0.031 

DrY Beans/Peas 5 8 24,000 150,000 0.160 

!Soybeans < 1 7 22,000 1,204,000 0.018 

bther** 2 708 2,000• 0.104b 

*Total Acres Treated sums all acres treated for a crop, including those acres that receive multiple treatments. 

** Other crops: Sweet Com, Lima Beans, Pumpkins 

•Other average pounds and average total acres treated are the sum of the average values for "other" crops. 

b Other Avg. AI Rate is the average of the average rates used on "other " crops. 

Source: Proprietary Data, 2009-2013 . 

In terms of pounds A.I. applied, North Dakota uses the most prothioconazole annually, at double 

the rate of the state with the next highest usage, Minnesota (Table 2). The high usage in North 

Dakota corresponds with the high acreage of wheat grown in the state during this time period. 

Approximately 33 million acres of wheat are grown annually in North Dakota, accounting for a 

quarter of all wheat production in the United States (proprietary data). The remaining 55 percent 

of prothioconazole usage is spread. over 31 other states (Table 2). 

Table 2. Comparison of States with Highest Use of Prothioconazole - Percent of Total 

Pounds 1\..1. A lied between 2009-2013. 

North Dakota 30 

Minnesota 15 

Michi an 7 

Illinois 6 

Geor ia 6 

Other* 36 

*Other states: NE, SD, FL, OH, ID, IO, MT, KS, 

NC, AL, SC, VA, KT, TN, AK, CO, WI, MO, TX, 

OK, ID, OR, WA, LA, MI, PA, MD, NM. 

Source: Proprietary Data, 2009-2013 . 

BEAD does not have any usage information on nursery stock usage. 

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CHEMICAL AND USE CHARACTERISTICS 

Prothioconazole is currently the sole fungicide in triazolinthiones, which was added in 2012 to 

the Group 3 ofDMI (DeMethylation Inhibitor) fungicides classified by the Fungicide Resistance 

Action Committee (FRAC). In general, Group 3 fungicides have a medium risk of resistance 

development and FRAC guidelines are available for resistance management (FRAC, 2015). 

Prothioconazole can be used as a rotational partner in a resistance management program. For 

example, resistance to strobilurin fungicides has been identified in the Ascochyta rabiei pathogen 

in Canada and North Dakota, and prothioconazole is the sole recommended Group 3 fungicide in 

the resistance management program in North Dakota providing an excellent control of Ascochyta 

blight of chickpeas (WFPM, 2014; Wurisch, 2014). 

ROLE OF PROTHIOCONAZOLE IN PEST MANAGEMENT 

Prothioconazole is registered under Section 3 of FIFRA for control or suppression of some 

important diseases including anthracnose leaf blight, gray leaf spot, and rust on com, Ascochyta 

blight and white mold on dry beans/peas, early leaf spot and white mold on peanuts, frog eye leaf 

spot and white mold on soybeans, Cercospora leaf spot and Rhizoctonia solani on sugar beets, 

Fusarium head blight (scab), and rusts on wheat, and pitch canker and fusiform rust on nursery 

stock such as nursery seedlings of lob lolly pine. A FIFRA Section 2( ee) recommendation for 

prothioconazole (Proline® 480 SC) was issued to control blackleg on canola, a disease that is not 

labeled (PPLS, 2015), in Kansas, Minnesota, Montana, North Dakota, Oklahoma, and South 

Dakota (CDMS, 2015). 

The agricultural use of prothiocomizole is mainly on field crops including com, dry beans/peas, 

peanuts, soybeans, sugar beets, and wheat. In particular recently, its seed treatment use 

increased significantly, from approximately 60,000 acres in 2012 to 3,500,000 acres in 2013 

(Proprietary Data, 2012-2013). Soybeans and wheat accounted for approximately 99% and 1 % 

of its 2013 seed treatment acreage, respectively. The seed treatment played a significant role in 

the 2012-2013 increase of the total acreage treated.by prothioconazole depicted in Figure 1. 

Prothioconazole is also needed for .control of a new invasive disease, V aldensinia leaf spot 

(Valdensinia heterodoxa), on lowbush blueberries spreading to Maine from Canada in 2009. No 

fungicides were recommended when this disease was first reported in Maine (Annis et al., 2009; 

Mack, 2009). Prothioconazole is the only registered and recommended fungicide against 

Valdensinia leaf spot (Annis and Yarborough, 2015). 

DATA NEEDS 

The Agency currently does not have complete information on prothioconazole. Quantitative 

usage information is not available for certain registered crops such as canola, nursery stock, seed 

treatment uses, and many other sites. Obtaining the following information, including total 

pounds active ingredient applied per year on a national or regional basis, percent crop/site 

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treated, application rates (typical and maximum), frequency and intervals of application, and 

target or niche pest species, may improve future assessments conducted by the Agency related to 

the use and importance of prothioconazole. 

REFERENCES 

Annis S, Yarborough D. 2015. Disease Control Guide for Wild Blueberries. Fact Sheet No. 219, 

UMaine Extension No. 2000 219. University of Maine. Revised April 2015. Accessed June 2015 

at http://umaine.edu/blueberries/factsheets/ disease/219-disease-control-guide-for-wildblueberries/. 

Annis S, Yarborough D, Hildebrand P. 2009. Valdensinia leaf spot, New Disease in Maine 

Blueberry Fields. University of Maine. Cooperative Extension: Main,e's native wild blueberries. 

Accessed June 2015 at http://umaine.edu/blueberries/factsheets/disease/valdensinia-leaf-spotdisease/. 

BEAD 2015. Prothioconazole Screening Level Usage Analysis. Biological and 

Economic Analysis Division, Office of Pestic,ide Programs, US Environmental Protection 

Agency. · 

BEAD 2006. "Public Interest Finding for Prothioconazole (DP 327796)." Richard Michell, 

Biological and Economic Analysis Division, Office of Pesticide Programs, US Environmental 

Protection Agency. October 26, 2006. 

BEAD 2015. "Review of Justification for Extension of Exclusive Use Period for 

Prothioconazole (DP#421072)." Carl Chen, Biological and Economic Analysis Division, Office 

of Pesticide Programs, US Environmental Protection Agency. May 4, 2015. 

CDMS. 2015. Crop Data Management Systems Label Search. CDMS, Inc. Accessed June 2015 

at https://premier.cdms.net/webapls/F ormsLogin.asp? /webapls/. 

EPA. 2007. Pesticide Fact Sheet Prothioconazole. Office of Prevention Pesticides and 

Toxic Substances, US Environmental Protection Agency. 

http://www.epa.gov/oppOOOOl/chein search/reg actions/registration/fs PC-113961 14-

Mar-07.pdf 

EPA. Pesticide Chemical Search Prothioconazole. Online: URL 

FRAC. 2015. Fungicide Resistance Action Committee (FRAC)- FRAC Code List© 2015. 

Accessed June 2015 at http://www.frac.info/docs/default-source/publications/frac-code-list/fraccode-list-2015-finalC2AD7 AA36764.pdf?sfvrsn=4. 

Kline and Company, Inc., 2002, 2004, 2006 

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Mack SK. 2009. Maine's wild blueberry crop imperiled by leaf spot fungus. Bangor Daily News. 

July 27, 2009. Accessed March 2015 at 

http://bangordailvnews.com/2009/07 /27 /news/mainersguos-wild-blueberrv-crop-imperiled-byleaf-spot-fungus/. 

PPLS. 2015. EPA-approved technical and end-use products/labels, The Pesticide Product Label 

System (PPLS). Accessed June 2015 for Proline® 480 SC at 

http://www3.epa.gov/pesticides/chem search/ppls/000264-00825-20150113 .pdf. 

Proprietary Data. 1998-2013. (pesticide usage data) 

WFPM. 2014. Diseases of special field crops-Chickpea. Chapter 8. Western Forum on Pest 

Management (WFPM). Accessed June 2015 at 

http://www.westemforum.org/Documents/WCPD/WCPD documents/Current%20Guideline%20 

Files/Ch%208%20Diseases%20ot°lo20Special%20Field%20Crops.pdf 

Wunsch M. 2014. Management of Ascochyta blight of chickpea. NDSU Carrington Research 

Extension Center. North Dakota State University. Accessed June 2015 at 

http ://www.ag.ndsu.edu/ carringtonrec/ documents/plantpathologvrd/noyeardocs/CHI CKPEAAsc 

ochytamwt.pdf. 

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