UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JUN 102015 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile for Registration Review: Fluoxastrobin (028869) 

FROM: Leonard Yourman, Plant Pathologist 

Biological Analysis Branch 

THRU: 

Cynthia Doucoure, Environmental Protection Specialist 

Science Information and Analysis Branch , 

Derek Berwald, Economist ~ f.l:- \J\A ~ Economic Analysis Branch 'J ) 

Biological and Economic Analys; Divi'.ion (7503P 

Arnet Jones, Chief \ 

Biological Analysis Branc 

Diann Sims, Chief 

Science Information and Analysis Branch 

Timothy Kiely, Chief fr4.- fAA.._ ( A 

Economic Analysis Branch ~ J v 0 

Biological and Economic Analysis Division (7503P) 

TO: Moana Appleyard, Chemical Review Manager 

Risk Management and Implementation Branch V 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: May 13, 2015 

Page 1 of 11 
SUMMARY 

Fluoxastrobin was registered in 2005 as a broad-spectrum fungicide of the quinone outside 

inhibitor (Qol) chemical group (also called strobilurin fungicide). Based on available private 

market research, agricultural use of fluoxastrobin in the U.S. fluctuated during the 2008 to 2013 

time frames with the highest reported use occurring during the 2010-2011 timeframes. The 

predominant uses, based on percent crop treated (PCT) are peanuts, peppers and wheat (<2.5%). 

The proportion of use of fluoxastrobin in terms of pounds applied are corn (36% ), soybeans 

(30%), and spring wheat (19%). BEAD also found that in 201 1, approximately 20,000 lbs a.i. of 

fluoxastrobin was reportedly used in the professional turf management and horticultural 

segments. 

INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of fluoxastrobin, and the general public. This document builds upon the data BEAD provides in 

the Label Use Information System (LUIS) reports and the Screening Level Usage Analysis 

(SLUA) to Registration Review teams. The document is based on information and data available 

to BEAD as of April 2015. 

HISTORY OF BEAD ASSESSMENTS FOR FLUOXASTROBIN 

BEAD prepared a Screening Level Usage Analysis (SLUA) in April 2015 that contained usage 

information on predominant uses of fluoxastrobin during the 2004-2013 time frame. 

The top uses in terms of average percent crop treated (PCT) and average pounds a.i. applied 

annually include the following: peanuts, peppers, and wheat, each with an average PCT of 

<2.5%. The average annual pounds a.i. applied on peppers (1,000) and peanuts (2,000) are 

relatively low, while the pounds a.i. applied on wheat (10,000) is considerably higher. 

To date, BEAD has not reviewed any Section 18 Emergency Exemption Requests for the use of 

fluoxastrobin; this should not be interpreted as a lack of benefits associated with the chemical. 

COMMON FORMULATIONS AND APPLICATION METHODS 

Fluoxastrobin is formulated as dry flowable, emulsifiable, flowable, and soluble concentrates, as 

well as granules, which are applied as broadcast, banded, chemigation, in furrow, or soil drench 

treatments using either aerial, ground, sprinkler irrigation, or granule applicator equipment. 

Fluoxastrobin is also applied as a seed piece treatment. Dual-a.i. products are available with 

chlorothalonil, myclobutanil, tebuconazole, or flutriafol. 

Page 2of11 
USE SITES 

Agricultural Use Sites: 

Fluoxastrobin is registered for use on crop subgroups 13-07G low growing berries, 1 C tuberous 

and corm vegetables, 48 leaf petioles, 9A melons, and 98 squash/cucumber, as well as com, 

fruiting vegetables, peanuts, potatoes, rice, sorghum, soybeans, and wheat. Fluoxastrobin is also 

used on sod farm turf. 

Non-Agricultural Use Sites: 

Fluoxastrobin is registered for use on ornamentals and ornamental lawns and turf. 

FLUOXASTROBIN USAGE 

Agricultural Usage Trend 

Registration of the fluoxastrobin Evito® product was approved in 2006, for use on fruiting 

vegetables, celery, peanuts, and potatoes. In 2010, fluoxastrobin was approved on wheat, sweet 

corn, field corn, and soybean. 

Agricultural use appears to have grown steadily over the 2008-2013 time frame, although use in 

the early years was quite small as the new product came onto the market and did not include corn 

or soybean use. Figure 1 shows the pounds applied from 2008- 2013, and Figure 2 shows the 

acres treated with fluoxastrobin, according to proprietary market research surveys. The most 

obvious feature of the use data in the figures is that data for 2011 is much larger than other years. 

Although it is possible that this is accurate (Evito® was approved for corn, soybean, and wheat in 

2010), we know that the sample sizes for fluoxastrobin use in this survey are quite small, and so 

it is possible that the relatively higher apparent use in 2011 is an artifact of the sampling method. 

For this reason, we have reduced the saturation of the 2011 data point in both charts, so that it 

does not camouflage what appears to be a real, substantial growth trend in fluoxastrobin use. 

During the 2008-2013 period, approximately 33,000 lbs a.i. were applied on average annually to 

363,000 acres at an overall average application rate of 0.09 lbs a.i. per acre. These average 

figures include 201 1 use data. By comparison, another Qol fungicide, pyraclostrobin, was used 

on average (2008-2012) on over 25 million acres per year with an annual average of 

approximately 2 million lb (2008-2012) (39% of the total lb was used on corn, 24% on soybean, 

and 5% on spring wheat) (BEAD, 2014). 

Page 3 of 11 
Figure I. Fluoxastrobin Usage: Pounds AI Applied, 2008-2013 

90.000 

0 

2005 

-

2009 -2010 

Year 

Source: EPA Proprietary Data, 2008-2013 

Page 4 of 11 

2011 2012 2013 
Figure 2: Fluoxastrobin Usage: Total Area Treated, 2008-2013 

l.~00.000 

,.. 

v 

wos -2C09 

Source: EPA Proprietary Data, 2008-2013 

Agricultural Usage: Top Crops, 2008-201 3 

-

2C10 

vear 

1011 101~ 2013 

Fluoxastrobin is used primarily on com, soybeans, and spring wheat as shown in Table 1. 

Together, they constitute 85% of total fluoxastrobin pounds a.i. applied and nearly 90% of acres 

treated. 

T a bl e I Fl uoxastro bm ' u sage on T op C rops. 2008 -2013 

Top Crops Proportion of Proportion of Avg A.I. Rate Labeled Max 

Total Pounds A.I. Total Area (lb a .i./acre) App Rate per 

Applied Treated Application 

(lb a.i./acre) 

Com 36% 24% 0.09 0.18 

Soybeans 30% 31% 0.06 0.18 

Wheat, Spring 19% 34% 0.04 0.12 

Other* 15% 11% 0.05-0.10 0. 12-0.18 

*Other crops include peanuts, peppers, potatoes. and winter wheat. 

Source: Proprietary Data, 2008-20 I 3 

Page 5 of 11 
Agricultural Usage: Top States. 2008-2013 

Fluoxastrobin is used primarily in Nebraska, Kentucky, and North Dakota. Together, they 

constitute approximately 60% of fluoxastrobin use in the U.S. (Table 2). Overall, tluoxastrobin 

occupies a relatively small portion of Qol use for these crops. 

T a e bl 2 Fl uoxastro b. m u . T S sage m op tat es, 2008 -2013 

Top States Proportion of Total Proportion of Total Avg A. I. Rate 

Pounds A.I. Applied Area Treated (lb a.i. per acre) 

Nebraska 24% 13% 0.11 

Kentucky 20% 20% 0.06 

North Dakota 17% 27% 0.04 

Other* 39% 40% 0.03 -0.18 

*Other states include AL, FL, GA. IL, IN, IA, KS. MN. MO. MT, OH. OR, SD, TN. WA. and WI. 

Source: Proprietary Data, 2008-2013 

Agricultural Use Intensity of Fluoxastrobin Use in the U.S. 

Another measure of usage is the use intensity. In this analysis, the use intensity is expressed as 

the average annual amount (in pounds) of the active ingredient applied per 1,000 acres of crop 

acres grown. This differs from the application rate, which is expressed as the pounds a.i. applied 

per treated area. Figure 3 spatially represents fluoxastrobin's use intensity in the U.S. in 

Kentucky, which is driven by production of soybeans. For more information on Figure 3, see 

Appendix A. 

Page 6of11 
~igure 3. Annual Average Agricultural Use Intensity of Fluoxastrobin (2009-2013). 

Pounds Active Ingredient 

per 1,000 Crop Acres Grown 

D No Date 

D <0.03 

D 003 - 009 

- 01 - 05 

- > 0 5 

(Source: Proprietary Data, 2009-2013) 

Nonagricultural Usage 

According to private market research, approximately 20,000 lbs a.i. were reportedly used by the 

professional turf management and horticultural segments in the U.S. in 201 1. This represents 

0.2% of the total fungicide pounds a.i. applied in these markets. 

Page 7 of 11 
BIOLOGICAL ASPECTS RELEVANT TO FLUOXASTROBIN 

The Fungicide Resistance Action Committee (FRAC) has designed a group classification system 

based on a fungicide's mode of action (FRAC, 2015). Fluoxastrobin is classified as a quinone 

outside inhibitor (QoJ) fungicide and FRAC lists it as a Group 11 fw1gicide. Qol fungicides 

have been very important in disease management since the first product (azoxystrobin) was 

registered in the late 1990s. They inhibit fungal respiration by binding to the "quinone outside" 

site of the mitochondrial cytochrome b protein. When the compound binds to the site it blocks 

electron transfer between cytochrome b and cytochrome c, which disrupts synthesis of ATP and 

ultimately inhibits cell respiration. 

Group 11 fungicides have been shown to exhibit cross-resistance; that is, a pathogen that has 

developed resistance to one of the Group 11 active ingredients is regarded to have resistance to 

the other Group 11 active ingredients. Nevertheless, each Qol active ingredient has a different 

chemical structure and characteristic (e.g., systemic mobility within the plant can vary among 

different active ingredients). Generally, Qof fungicides have limited systemic movement in the 

plant but do have translaminar movement across the leaf. Fluoxastrobin is one of only two 

registered fungicides (the other being azoxystrobin) that move within the xylem of the plant, thus 

engendering some curative ~swell as preventative activity (e.g., Bradley, 2011; Dufault, 2013). 

ROLE OF FLUOXASTROBIN IN DISEASE MANAGEMENT 

Qol products are among the most widely used fungicides due to their effectiveness in managing 

many diseases caused by numerous fungal pathogens (Vincelli, 2012). Resistance has been 

documented for some important fungal pathogens (e.g., Faske, 2012) and product labels have 

extensive resistant management language to maintain the effectiveness of this group of 

fungicides. Many Qof fungicides are available as mixed-a.i. products for improving efficacy and 

to enhance resistance management. Because of their high efficacy in inhibiting spore 

germination and their tendency to accumulate in the cuticle layers of the leaves, Qol fungicides 

are most effective when applied as protectants before pathogen spores penetrate the leaves (e.g., . 

For many uses Qol fungicides may be interchangeable in terms of effectiveness, while in other 

situations individual Qol active ingredients may exhibit different levels of efficacy. As such, in 

some situations, a particular Qol active ingredient may be recommended in preference to another 

Qol fungicide. Where curative activity is required fluoxastrobin might be selected by a user 

preferentially compared to some other Qol fungicides due to its movement through the xylem 

and, therefore, fluoxastrobin may have benefits for curative treatments. However, BEAD did not 

find extension information specifically recommending fluoxastrobin rather than other QoI 

fungicides to manage target diseases. 

Qol fungicides are effective against several diseases of field crops as well as vegetable and fruit 

crops. Historically, fungicides were little used on field crops such as com and wheat (e.g., Isleib, 

2013). Use on com increased substantially in 2007, due in part to price of hybrid com, increase 

in disease in some areas, newer fungicides that were available, and increased marketing by 

manufacturers. 

Page 8 of 11 
Fluoxastrobin and other Qol fungicides target rusts of corn, soybean, and wheat (Kemerait, 

2012). Qol fungicides, including tluoxastrobin, have been used to manage soybean aerial web 

blight and frogeye leaf spot (e.g., Purdue, 2014), although frogeye leaf spot pathogen has shown 

resistance in some locations (e.g., Faske, 2012). Fluoxastrobin may be used to manage wheat tan 

spot although efficacy differences among Qol fungicides have been noted (e.g., fluoxastrobin 

was rated Very Good; pyraclostrobin rated Excellent) (MU, 20 12). Fluoxastrobin and other Qol 

fungicides also may be used to manage wheat Septoria leaf blotch and wheat glume blotch. 

Qol fungicides, including fluoxastrobin can be very effective against anthracnose fruit rot and 

leather rot of strawberries applied postbloom to harvest (Ellis, 2013 ). Qol fungicides have been 

used to manage important melon/cucurbit diseases gummy stem blight and downy mildew, but 

widespread pathogen resistance has been found to this fungicide group (e.g., Roberson, 2007). 

INFORMATION THAT MAY BE USEFUL FOR BEAD'S FUTURE WORK ON 

FLUOXASTROBIN 

• Information of any specific preferential uses for fluoxastrobin compared to other 

available Qol fungicides including particular disease/crop systems or locations 

REFERENCES 

BEAD. 2014. BEAD Chemical Profile for Registration Review: Pyraclostrobin (099100). 

February 27, 2014. Biological and Economic Analysis Division, OPP. 

Bradley, C. 2011. Providing some clarity on fungicide products. The Bulletin Issue 2, Article 4, 

April 8, 20 11. University of. Illinois Extension. 

http://bullctin.ipm.illinois.edu/article.php?id= 1454; 

Dufault, N. 2013. Fungicide basics and use in vegetable disease management. University of 

Florida Extension. http://hos.ufl.edu/sitcs/dcfault/filcs/focultv/gdliu/ Dufault.pdf 

Ellis, M.A. 20 13. Using fungicides to control strawberry fruit rots in Ohio-2012. Ohio State 

University Extension. http://strawberries.ces.ncsu.edu/\\ p-content/uploads/2013/05/Fungicidcsfor-S trawberrv-Frui t-Rots-iti. pdf 

EPA Screening Level Usage Analysis (SLUA), April 2015 

Faske, T. 2012. Strobilurin-resistant frogeye leaf spot confirmed in Arkansas. Delta Farm Press, 

Aug. 17, 2012. http://dcltafarmpress.com/sovbeans/strobilurin-rcsistant-frogevc-lcaf-spotcon fi m1cd-arkansas 

Page 9 of 11 
FRAC. 2015. Fungicide Resistance Action Committee Code List: Fungicides Sorted by Mode of 

Action. http://www.frac.info/docs/default-source/publications/frac-code-list/frac-code-list-2015-

fina!C2AD7 AA36764.pdf?sfvrsn=4 

Isleib, J. 2013. Foliar fungicide use in com. Michigan State University Extension. 

http://msuc.anr.msu.edu/news/foliar fungicide use in corn 

Kemerait, R. C. 2012. Fungicides and management of rusts. University of Georgia Extension. 

http ://v.rww. plantmanagementnetwork.orn/proceed ings/FCRS/201 1 /Presentations/Kemerai t. pdf 

MU. 2012. Wheat disease situation. University of Missouri Extension. 

http://ipm.missouri.edu/IPCM/2012/4/2012-Wheat-Disease-Situation/ 

Proprietary Data, 2008-2013 

Purdue. 2014. Fungicide efficacy for control of soybean foliar diseases. Purdue University 

Extension. https://www.extension.purdue.edu/extmedia/BP/BP-l 6 l-W.pdf 

Vincelli, P. 2012. Qol (stro~ilurin) fungicides: Benefits and risks. Plant Health Instructor, 

APSnet Publication. 

http://www.apsnet.org/edcenter/advanced/topics/Pages/StrobilurinFungicides.aspx. 

Page IO of 11 
APPENDIX A 

The map included herein is primarily for the use of the risk assessors in the Environmental Fate 

and Effects Division. The map provides a very broad geographical view of the average annual 

amount (in pounds) of the active ingredient applied per 1,000 acres of crop acres grown. These 

data are included in the maps because risk assessors are interested in the amount of a pesticide 

used across agricultural land. The calculated values presented in the map are not equivalent to 

an application rate (lb a.i./A). 

The data used to generate these maps have several limitations. Any interpretation of the maps 

should consider the underlying data and the associated limitations carefully. 

The numerator (annual average pounds applied) is based on private market surveys of pesticide 

use in agriculture averaged over the last five years (Proprietary Data, 2009-2013). These surveys 

cover about 60 crops and ar~ targeted in states that produce the majority of the crop. Although 

the surveys capture most of the use of a particular active ingredient in agriculture, there are 

several limitations to these surveys. 

• States with minor production of a surveyed crop are not sampled 

• Not all types of pesticides are surveyed in every crop in every year 

• Many specialty crops with very small acreages are not included in the survey 

The result of these limitations is that states that show no usage may actually have a small amount 

of the active ingredient being used. In some cases the displayed use intensity may be distorted 

because the surveyed crops and the reported pesticide usage may not accurately represent the 

actual pesticide usage on the crops produced in the state. 

The denominator ( 1,000 crop acres grown) was also obtained from the same private market 

survey database. The "Crop Acres Grown" variable represents the total acres grown in a given 

state of all of the surveyed c.rops. This value is independent of pesticide usage and pesticide 

registration. It is important to note that the surveyed crops (about 60) are sampled from states 

that are major producers of each crop. Therefore, there are cases where the actual crop acreage in 

a state is higher than that reported by crop acres grown in the survey because either that state 

and/or crop was not included in the survey. 

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 legend bins will likely be different. 

Page 11 of 11