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

## JUN 17 2Dt5
MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Flumetralin (123001) 

### FROM:

THRU:

TO: Leonard Yourman, PlantPathologist 

# f Biological Analysis Branch 

## (j 1

Arnet Jones, Chief Biological Analysis Branch Diann Sims, Chief

# )fl;...~ Science Information and Analysis Branch Biological and Economic Analysis Division (7503P)

Katherine St. Clair, Chemical Review Manager Pesticide Re-evaluation Division (7508P)

Peer Review Panel: June I0, 20I5


### SUMMARY Flumetralin is a plant growthregulator that has beenregistered for use ontobacco since 1983 (EPA, 2007). It is used to control axillary bud (sucker) growth on tobacco plants. The current average total annual domestic usage offlumetralin averages approximately 100,000 pounds active ingredient (a.i.) per year. Flumetralin use has increased in recent years possibly due to an attemptto reduce maleic hydrazide residues on tobacco. There are no registered food or feed uses for flumetralin.


### INTRODUCTION The Biological and Economic Analysis Division (BEAD) Chemical Profile (BCP) provides an overview ofthe pest managementroles and quantitative usage information for flumetralin. TheBCP includes summaries ofprevious BEAD products and available public and/or private use and usage data for flumetralin to describe the role ofthis chemical inpest management. Additional information onuse is available inthe Flumetralin Label DataReport. Information provided in this BEAD Chemical Profile (BCP) maybe used by stakeholders (e.g., users and registrants), OPP risk assessors, and OPP risk managers, and the general public during the Registration Reviewprocess ofthis pesticide.


### HISTORY OF FLUMETRALINAND BEAD PRODUCTS No assessments have been conducted for flumetralin.


### USE SITES Agricultural Use Sites Flumetralin is only registered for use on tobacco.


### FORMULATIONS Flumetralin is formulated as an emulsifiable concentrate.


### APPLICATION METHODS Flumetralin is applied as a broadcast, drench, and directed spray. Droplines, power sprayers, backpack sprayers, and vehicle propelled sprayers can be used.


### USAGE Agricultural Usage Usage ofFlumetralinhas increased steadily, interms ofbothpounds a.i. applied and total acres treated, more than doubling between 1998 and 2013 (Figure 1 ).

2250,000

Pounds Al Applied & Total Acres

Treated

0 oo m o M N m**~ ~** **~ ~**  oo m o M N m m m 0 0 0 0 0 0 0 0 0 0 M M M M m m o o o o o o o o o o o o o o M M N N N N N N N N N N N N N N**Pounds** Al _._Total Area Treated Figure 1. Flumetralin TotalAcres Treated and TotalPoundsA.I. Applied (1998-2013). Source: Proprietary Data, 1998-2013 

### The increase in flumetralin usage is particularly interesting when viewed in terms ofthe overall decrease in total acres oftobacco grown. In the time period shown above, 1998-2013, tobacco acreage decreased by nearly 55%. In the same time period, however, tobacco acres treated with flumetralin increased by 50%. Table 1 shows average usage from 2004-2008 and 2009-2013. Betweenthese two time periods, average pounds A.I. applied, total acres treated, and percent crop treated all increased approximately 40%, while average application rates remained relatively steady. This increase in use offlumetralin may be due to a concern for maleic hydrazide residues and the substitute (or partial substitute) offlumetralin inplace ofmaleic hydrazide (e.g., Fisher and Stewart, 2010; Gooden, 2012). T bl 1 Fl 

### r u T C A AIR 2004 2008 d 2009 2013

a e 

## . umetra m se on op rops: veraee 

# .. ate, 

## - an 

### - AveragePounds Average Total Average A.I. PercentCrop Years Crop Acres Treated Rate A.I./year /year* (lbs a.i./acre) Treated 2004-2008 Tobacco 68,000 100,000 0.67 30 2009-2013 Tobacco 103,000 170,000 0.61 50 *Total Acres Treated sums all acres treated for a crop, mcludmg those acres that receive multiple treatments. Source: Proprietary Data, 2009-2013


### While overall usage has increased, the geographic distribution ofapplication has remained fairly consistent. From 2003 to 2007 and 2008 to 2013 overhalfofflumetralin was applied in North Carolina, followed distantly by Kentucky and Virginia, with the remaining 15 percent ofusage splitbetween six to ten other states (Table 2).



### 3Table 2. Comparison ofStateswith HighestUse ofFlumetralin

- P t fT t IP d AI A rd b tw 2004 2008 d2009 2013

ercen o oa oun s 

# .. ,0011e e een 

## - an 

### - 

# . 2004-2008 2009-2013 Average Annual = 68,000 lbs Average Annual= 103,000 State %Lbs State o/o Lbs North Carolina 55 North Carolina 60 Kentucky 15 Kentucky 15 Virginia 15 Virginia 10 South Carolina 5 South Carolina 5

Tennessee 5 Tennessee 5

Other* 5 Other* 5 *Other states: CT, FL, GA, ID, OH, PA, WI, WV *Other states: GA, FL, OH, PA, Source: Proprietary Data, 2003-2012



### 4

### Geographic Distribution ofFlumetralin Usage The map below shows Flumetralin use intensity, in terms ofpounds a.i. applied per 1,000 acres ofstate crop area grown (Figure 2). As shownin Table 2, usage is highest inthe tobacco growing states ofthe southeast.

PoundsActive Ingredient per 1,000 Crop Acres Grown c=JNoData LJ <0.5 0

.6

- 1

.0

. 1

. 1-3

.0

- >3.0 

### Figure 2. Annual average agricultural use intensity ofFlumetralin (2009-2013). Source: Proprietary Data 

### Figure 2 provides a very broad geographical view ofthe average annual amount (in pounds) of Flumetralin applied per 1,000 acres ofcrop acres grown. The calculated values presented in the map are not equivalentto an application rate (lbs a.i./a), therefore, the map may show areas of high use intensity that do not necessarily correspondto the states listed in Table 2 since those are the states with the highest use ofFlumetralinbased onpounds active ingredient applied. More information about this map is presented in Appendix A.



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### CHEMICALAND USE CHARACTERISTICS FORCONTROL OFAXILLARY BUDS (SUCKERS) Flumetralin is a plant growth regulator used on tobacco for control ofaxillary bud (sucker) growth. Reduction ofsuckers increases the yield and quality ofthe tobacco leaves. While not a pesticide, effective suckeringmay help reduce late seasontobacco homworm infestations (Crop Profile WV, 1999). Flumetralin is used for control ofsuckers on flue-cured, burley, and cigar tobacco plants. Three types ofchemicals are used to manage sucker growth in tobacco-systemic (maleic hydrazide), contact (fatty alcohols) and locally systemic dinitroanalines (flumetralin and butralin) (Crop Profile VA, 2001; Crop Profile TN, 2008). Chemical sucker control has been applied to nearly all oftobacco acreage in Virginia and North Carolina (Crop Profile VA, 2001; Crop Profile NC, 1999). Topping occurs whenplants begin to develop a flower bud, generally whenthe flower bud begins to elongate and when 50% ofthe plants have reachedthis stage. Tobacco topped at bud elongation stage can yield 300 or morepounds per acre compared to tobacco that is topped at full bloom (Crop Profile TN, 20

_ 08). Removing the tops oftobacco plants removes the dominant effect ofthe terminal shoot over lateral shoots (suckers), thus allowing rapid growth ofsuckers. Topping is done byhand using a knife with workers generally wearing cloth gloves. Suckercontrol chemicals are applied aftertopping, usually within two days. Darktobacco types generally have less maleic hydrazide (MH) use and would be substituted withproducts containing butralin, flumetralin and/or fatty alcohols (Crop Profile TN, 2008). Combinations of these products are often used to improve sucker control. Locally systemic chemicals; such as flumetralin, are not true systemics and must be absorbed at the axillary bud. As the sucker grows in the leafaxil, the axillary bud grows away from the leaf axil and is out ofthe path ofthe chemical as it travels downthe stalk. Therefore, suckers must not be greaterthan 1-inch long at the time ofapplication. Flumetralin is applied like a contact solution, butnot until the plants are inthe elongated-buttonto-early-flower stage (NCSU, 2015). This is a few days before MH application. The objective is to apply flumetralin so that it touches the small suckers (similarto contact solutions) since, unlike MH, flumetralin does not move to suckerbudsthroughthe leaves. Flumetralinmust first wet the suckers like a fatty alcohol contact before it can stop cell division like a systemic (contact-local systemic). It has no true contact activity, andthe controlled suckers do nottum brown orblack, but rather look yellow and deformed for several weeks aftertreatment (NCSU, 2015). Thorough coverage maximizes the effectiveness offlumetralin. Some applications including dropline andjug applications (see below) are labor-intensive with workers in close contact withthe chemical. 

### Application offlumetralin (from Fisher and Stewart, 2010) Because flumetralin needs to run down the stalk and wetthe suckers, it should be applied with contact nozzles (TG3 -TG5-TG3 per row or equivalents), with a 50 gallon per acre delivery volume, and at a low pressure (20 to 25 psi). Flumetralin does not completely control suckers longerthan I inch, so you should remove larger suckers before application. Full-season sucker control can be expected on small suckers wetted by the flumetralin solution, but missed suckers

6will continue to grow and should be removed by hand. Missed leafaxils with flumetralin are typically in the top ofthe plant and may result from leaning stalks, leaves covering the leafaxil, orboth preventing proper "rundown" offlumetralin into the leafaxil. Even though the flumetralin label allows for application up to one gallon per acre, the general recommendation has been for application rates of2 quarts per acre. Increasing flumetralin rates from 2 quarts per acre to 3 quarts or 1gallon in a single mechanical application has not consistently improved sucker control, primarily because control is so dependent on coverage of all leafaxils, which is not improved by increasing flumetralin rates. However, application of2 quarts offlumetralin followed by 1quart offlumetralin seven days later improves sucker control compared to 3 quarts offlumetralin applied in a single application. This would indicate that increasing rates offlumetralin above 2 quarts per acre is only advantageous ifthe flumetralin is applied in a split application. It is likely that split applications reduce the number ofmissed leafaxils-the main cause ofpoor sucker control when MH is not used. 

### Dropline Application Dropline applications are generally the most effective way to apply flumetralin because they allow for the most consistent ability to apply the flumetralin solution to each leafaxil. However, dropline applications require more labor, which is not always available on the farm depending on the scope ofthe farming operation and/or the degree ofmechanization ofother farming operations. Even though the best sucker control from flumetralin is achieved with dropline applications, growers must make the decision on whether such application methods are feasible and practical on a case by case basis depending on their individual situations. A dropline application is made manually, with a single line perrow, coming offofa powered sprayer (typically a high clearance sprayer). Multiple lines can be used at one time and each line has a valve (trigger) and a single TG nozzle. Flumetralin is then applied on a plant by plant basis by manually holdingthe nozzle overthe center ofthe plant and opening the valve or "trigger" long enough to apply a desired amount ofsolution to each plant. Dropline applications should be initiated when approximately halfofthe plants are in the elongated bud to early-flowering stage. Plants should be topped and then flumetralin applied within 24 hours. In many cases, both topping and applying flumetralin with a dropline can be accomplished atthe same time. Where uniformity is a problem and some plants are laterto mature, a second trip through the field to top and dropline flumetralin only onthose plants may be needed. Ifa second trip is needed, it can usually be accomplished at a faster speed than the original dropline application. Only apply flumetralin with a dropline once per plant per season. Another advantage ofdropline applications is that they can reduce the need for contact applications because dropline applications offlumetralin can be made at topping. In many cases contact applications, when used in conjunction with a dropline application offlumetralin, are only used to allowthe crop to "even out" so that all plants are atthe correct stage for flumetralin application and only one trip across the field with droplines is needed. Contacts may also be used in this scenario to delay flumetralin applications for better managementoflabor resources by controlling sucker growth until labor is available: In a dropline application, flumetralin should be mixed the same as with mechanical applications, 2 to 3 quarts offlumetralin in 49.5 to 49.25 gallons ofwater, respectively. The flumetralin solutions should be applied alone to deliver 1/2 to 213 ofa fluid ounce ofsolution per plant. Dropline applications offlumetralin require personal protective



### 7equipment (PPE) to be worn by workers. Read the label for each source offlumetralin carefully (Prime+, Flupro, Drexalin Plus) to determine the requirements for dropline applications.


### Sucker control offlue-cured tobacco are usually addressed by using one oftwo options (e.g., Crop Profile VA, 2001): 1. Sequential control with two contact applications followed by MH orMH and flumetralin in a tank-mix applied overthe top as a foliar spray; or 2. Individual plant methods where plants are treated individually with a 2% flumetralin application once, making the application down the stalk withjugs or droplines. Sucker control inburley tobacco is different in that contacts are not generally used and MH or MH 

### +flumetralin or MH 

### +butralin is applied once. Sucker control is easier with burley tobacco since the crop is harvested 3 to 5 weeks after topping compared to flue-cured which requires 1 

### O+ weeks ofcontrol (Crop Profile VA, 2001). Acres treated with chemical growth regulators were estimated for the 2007-season (Table 3). Because ofMHresidues found in cured tobacco state extension has recommended closely following MH label warnings orthe use ofanother chemical, such as flumetralin, for sucker control (e.g., Crop Profile TN, 2008; Fisher and Stewart, 2010; Gooden, 2012). Table 3. Estimated GrowthRegulator Percent Acres Treated (2007) Tobacco Production

Active Ingredient Burley Tobacco DarkTobacco (% Acres Treated) (% Acres Treated) Butralin* 25 40 Maleic hvdrazide 90 20 Flumetralin* 35 60 Fatty alcohols 30 70 Source: Crop Profile TN, 2008. * Products containing butralin or flumetralin are often used in conjunction with maleic hydrazide.


### REFERENCES BEAD. 2015. Flumetralin Screening Level Usage Analysis. Biological and Economic Analysis Division, Office ofPesticide Programs, US Environmental Protection Agency. Crop Profile NC. 1999. Crop Profile for Tobacco inNorth Carolina. http://www.ipmcenters.org/cropprofiles/docs/NCtobacco.pdf Crop Profile TN. 2008. Crop Profile for Tobacco Production in Tennessee. http://www.ipmcenters.org/cropprofiles/docs/TNtobacco2008.pdf Crop Profile VA. 2001. Crop Profile for Tobacco in Virginia. http://www.ipmcenters.org/cropprofiles/docs/vatobacco.pdf

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### Crop Profile WV. 1999. Crop Profile for Tobacco in West Virginia. http://www.ipmcenters.org/cropprofiles/docs/WVtobacco.pdf EPA. 2007. Registration Eligibility Decision Flumetralin. Prevention Pesticides and Toxic Substances, US Environmental Protection Agency. http://www.epa.gov/pesticides/reregistration/REDs/flumetralin red.pdf Fisher, L. and Stewart, S. 2010. Recommendation for controlling suckers without using MH. North Carolina State University Extension, Dept. ofCrop Science. http://www.ces.ncsu.edu/files/library/39/Recommendations%20for%20Controlling%20S uckers%20without%20Using%20MH.pdf Gooden, D. 2012. Tobacco sucker control. South Carolina Pest Management Handbook for Field Crops, 2012. Pp 257-260. ClemsonUniversity Extension. http://www.clemson.edu/extension/rowcrops/pest/files/2012%20PMH%20Web%20Page %20Version/2012%20PMH TOBACCOSC.pdf NCSU. 2015. Topping & sucker control-Chemical sucker control. North Carolina State University Extension. http://tobacco.ces.ncsu.edu/topping-sucker-control-chemicalsucker-control/ Proprietary Data. 1998-2013. (pesticide usage data)

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### APPENDIXA The map included herein is primarily for the use ofthe risk assessors in the Environmental Fate and Effects Division. The map provides a very broad geographical view ofthe average annual amount (in pounds) ofthe active ingredient appliedper 1,000 acres ofcrop acres grown. These data are included in the maps because risk assessors are interested inthe amount ofapesticide used across agricultural land. The calculated values presented inthe map are not equivalentto an application rate (lb a.i./A). The dataused to make these maps have several limitations. Any interpretation ofthe maps should considerthe underlying data and the associated limitations carefully. 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 produce the majority ofthe crop. Although the surveys capture most ofthe use ofa particular active ingredient in agriculture, there are several limitations to these surveys.

• States withminorproduction 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 inthe survey The result ofthese limitations is that states that showno usage may actually have a small amount ofthe active ingredientbeing 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 ofall ofthe surveyed crops. This value is independent ofpesticide usage and pesticide registration. It is important to note thatthe surveyed crops (about 60) are sampled from states that are major producers ofeach crop. Therefore, there are cases where the actual crop acreage in a state is higher than thatreported by crop acres grown in the survey because either that state and/or crop was not included inthe survey. The reader should pay particular attentionto the figure legends and realize that a map prepared for a particular chemical is not directly comparable to a map preparedfor a different chemical as the legend bins will likely be different.

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