UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , D

.C

. 20460



## AUG 12 2013

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

SUBJECT: 

### BEAD Chemical Profile (BCP) for Registration Review: Acibenzolar-S-methyl (061402)
FROM:

THRU: 

### Carl Chen, Plant Pathologist Biological Analysis Branch JihadAlsadek,Economist 

# .,rlJ**A-£..~** Science Information and Analysis Branch
Michelle Ranville, Economist 

### 1

# ll(_(XJ Economic Analysis Branch**~ ~**  

### Biological and Economic ysis Division (7503P)
Arnet Jones, Chief Biological Analysis Br Diann Sims, Chief

# ~,_,J**,__,.-­** Science Information and Analysis Branch Timothy Kiely, Chief ....-,(1 

# V 

# l.._**~** B

## Au:J~~**Z0(~** Economic Analysis Branch i -, 

# 'V"u"· f1 

### Biological and Economic Analysis Division (7503P) 1trr

### -r.~**~:\et--Y** TO: 

### Dana Friedman, Chemical Review Manager Risk Management and Implementation Branch 3 Pesticide Re-evaluation Division (7508P)
Product Review Panel date: June 12, 2013
INTRODUCTION


### The purpose ofthis document is to convey usage information and a broad overview ofthe pest managementrole ofacibenzolar-S-methyl as itbegins to undergo Registration Review. The anticipated audience consists ofthe team ofEPA staffcurrently evaluating the registration status ofacibenzolar-S-methyl and eventually the general public. This document builds upon the Label Use Information System (LUIS) reports and Screening Level Usage Analysis (SLUA) that

1BEAD provides to the Registration Review team. This document is based on information and data available to BEAD as ofMay 2013. A RED was done in 2007 for this chemical. Acibenzolar-S-methyl belongs to the benzo-thiadiazole (BTH) chemical group offungicides which controls or suppresses diseases by inducing the hostplant's defense responses (FRAC, 2013). The chemical has no direct activity on pathogens. This chemical is unique 

### in thatit is registeredto target fungi, bacteria, andplant-parasitic nematodes. 

### Itis registered to control or suppress some importantplant diseases such as downy mildewonlettuce, spinach, cucurbits, and cole crops; bacterial diseases caused by

### Xanthomonas spp. or

### Pseudomonas syringae on tomatoes, peppers, and cucurbits; blue mold ontobacco; and blackrootrot, Fusarium wilt, and early seasonplant-parasitic nematodes oncotton.
COMMON FORMULATIONS AND APPLICATION METHODS Acibenzolar-S-methyl is formulated as water dispersible granules and flowable concentrate. Acibenzolar-S-methyl maybe applied as a band treatment, broadcast, chemigation, directed spray, foliar treatment, seedtreatment, or soil/mediatreatment.
USE SITES Agricultural Use Sites Acibenzolar-S-methyl is registered oncole crops, cotton, cucurbits, fruiting vegetables, lettuce, onion, peppers, chili peppers, small fruits (e.g., blueberries), spinach, sunflower, tobacco and tomato. Non-agricultural Use Sites Acibenzolar-S-methyl is registered on commercial/industrial lawns, golfcourse turf, ornamental lawns and turf, and ornamental sod farm (turf).
USAGE Agricultural Usage Figure 1 shows the use ofacibenzolar-S-methyl interms ofannual total pounds active ingredient used for the period 2000-2011. This time frame shows an increase inusage from 2000-2005, and a decrease thereafter through 2011. During this time period (2000-2011), the annual total agricultural usage averaged approximately 1,000 pounds a.i. to treat approximately 48,000 acres for an average application rate of0.02 lbs. a.i. per acre. The average annual application rates for the top crops are 0.02 lb. a.i. per acre for both spinach and lettuce, and 0.01 lb. a.i. peracre for tomatoes.

2

### Fi 2,500

PoundsA.I.

0 0 0 N .-t 0 0 N N 0 0 N

Source: Proprietary Data, 2000 -2011 ("() 0 0 N v 0 0 N L.l1 0 0 N Years1.0 0 0 N 

## " 0 0 N co 0 0 N C'l 0 0 N 0 .-t 0 N .-t .-t 0 N



### Figure 2 presents the agricultural usage for the more recent 2007-2011 timeframe. Usage averaged approximately 1,000 pounds active ingredient (a.i.) annually on 53,000 treated acres with an overall applicationrate of0.02 lbs. a.i

.per acre. During this time frame, the crops with the highest use interms ofpercent oftotalpounds ofactive ingredient applied are spinach (64%), lettuce (23%), and tomatoes (10%). Other crops accounted for 3% ofuse.

PoundsA.I.



## " 0 0 N co 0 0 N

Source: Proprietary Data, 2007-2011 C'l 0 0 N Years 0 .-t 0 N



### 3 .-t .-t 0 N -+-Spinach

_.. Lettuce

....-Tomatoes

### Table 1. 

### Acibenzolar-S-methyl Top Crops in Terms ofPercent ofTotalPounds Applied, TotalAcres Treated (TAT), andAverage AnnualApplication Rates in 

### Lbs. a.i. perAcre

Tomatoes %Total Pounds A.l. Applied

Source: Proprietary Data, 2007-2011 

### % Total Acres Treated

16 16 Average Percent Crop Treated Average Annual 

### Application Rates in Lbs. A.I./A

On average, the states withthe most agricultural usage interms ofpercent oftotal pounds a.i. applied are California (76%), Arizona (11%), and Florida (10%). (Proprietary Data, 2007-2011). Agricultural Usage by Crop Reporting District
Another measure ofusage is the use intensity. Inthis analysis, the use intensity is expressed as the pounds a.i. applied perthousand acres ofland infarms. This differs from the application rate, which is expressed as the pounds a.i. applied pertreated area. The average applicationrate for the period 2007 to 2011 is 0.02lbs. a.i. per acre or 20 lbs. per 1000 treated acres. As shown inFigure 3, however, maximum use intensity is about 0.147lbs per 1000 acres oflandin farms. The areas depicted in red onthe map in California are mainly for lettuce and spinach in particularbecause ofthe high proportion ofcrop acres inleafy vegetable production in CA. Intensity may also be linkedto the high applicationrate for lettuce and spinach (0.02 lb. a.i./a) comparedto the tomato applicationrate (0.01lb. a.i./a). It

### is importantto note that usage data may not cover all states where a surveyed crop is grown. For example, use ofacibenzolar-Smethyl does not appear in Colorado althoughrecords ofEmergency Exemptions indicate that it has beenrequested for use there ononions. Appendix A contains additional details onthe sources ofdataused in Figure 3.

4

### Figure 3. Acibenzolar-S-methyl Use Intensity by Crop Reporting District (2007-2011)

Average Pounds Per 1,000Acres of Farmland

- <0.010 0.010- 0.029 0.030- 0.053 0.054-0.147

Sources: ProprietaryData, 2007-2011; USDA, 2007



### BIOLOGICAL ASPECTS RELEVANT TO ACIBENZOLAR-S-METHYL Acibenzolar-S-methyl is unique in control and suppression ofdisease infoliar application and seed treatment. Forbestresults itmustbe appliedpreventively, before infection occurs and before symptom development (UC IPM, 2012). The chemical has no direct activity on pathogens. Itexhibits a unique mode ofaction to induce systemic acquired resistance (SAR) (Monda! et al., 2005). Resistance is notknown for acibenzolar-S-methyl (FRAC, 2013). Resistance management practices described onthe label include rotating and/or tank mixing with pesticides with different modes ofaction since plantpathogens may develop tolerance to host plantresistance.


### THE ROLE OF ACIBENZOLAR-S-METHYL INPEST MANAGEMENT
The role ofacibenzolar-S-methyl inpest management is unique. It is a control option in a pest and resistance management program involving diseases and alternatives that have a high risk of developing resistance. Itis a candidate suitable for an integratedpest management (IPM) program because it is relatedto host plant resistance and cultural practices. Itis used to control 5

# \ bacterial diseases as an alternative to antibiotics and EBDC fungicides such as mancozeb. Itis employed not only as a foliar applicationbut also a seed treatment. Finally, acibenzolar-Smethyl is unique inthat it canbe used to control nematode pests. Acibenzolar-S-methyl has also been used to control iris yellow spot virus (IYSV) under emergency exemptions through Section 18 ofthe Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Emergency exemptions for the use ofacibenzolar-S-methyl on onions inthe state ofColorado were granted for three consecutive years from 2007 to 2009. BEAD conductedtwo reviews for this emergency exemption request (Yourman and Rim, 2004; Yourman and Faulkner, 2009), both ofwhich found the situation in Colorado onions to be urgent and non-routine and likely to cause significant economic loss. The use was approved later for a FIFRA Section 3 registration. Downy mildew is the mostwidespread and destructive spinach disease in California. Acibenzolar-S-methyl has beenrecommended for use against downy mildew in 10 counties, many ofthem are inthe areas depicted in red onthe map (Figure 3; UC IPM, 2012). White rust, a majorfoliar fungal disease ofspinach inthe SoutheasternU.S., was controlled by a combination ofacibenzolar-S-methyl and strobilurin without causing leafchlorosis (Leskovar and Kolenda, 2002). In 2011, acibenzolar-S-methyl was the top fungicide in acreage treated, suggesting that itplayed a significant role in spinach disease management (Proprietary Data). Acibenzolar-S-methyl may also have potential for controlling peststhat are not listed onthe label. Its unique mode ofaction thatmimics SARresponse inmanyplant species canbe considered as an asset for control ofsome diseases. A FIFRA Section 2(ee) recommendation for Daconil ActionTM, a combinationproduct ofactive ingredients acibenzolar-S-methyl and chlorothalonil, has been issued for suppression ofPythium blight and bacterial wilt onturfgrass in California, Florida, New York, Texas, and other states (CDMS, 2013).
DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ONACIBENZOLAR-SMETHYL
Additional information, interms ofpounds a.i. applied, average application rate, regional application, time ofapplication, and number ofapplications per year onnon-agricultural sites (e.g., ornamental turf) would improve future assessments ofthe importance ofacibenzolar-Smethyl for pestmanagement and may be useful as part ofthe registrationreview ofthis pesticide.

REFERENCES
CDMS. 2013. Crop Data Management Systems. http://premier.cdms.net/webapls. Accessed May 2013.EPA. Acibenzolar-S-methyl. Online: http://iaspub.epa.gov/apex/pesticides/f?p=CHEMICALSEARCH:3:0::NO:l,3,31,7,12,25:P3 XCHE MICAL ID:79 FRAC. 2013. Fungicide Resistance Action Committee. http://www.frac.info/frac/index.htm Accessed May 2013.



### 6Leskovar Dl, Kolenda K. 2002. Strobilurin

### + acibenzolar-S-methyl controls white rust without inducing leafchlorosis in spinach. Annals ofApplied Biology, 140: 171-175. Mondal, A. H., D. B. Nehl, and S. J. Allen. 2005. Acibenzolar-S-methyl induces systemic resistance in cotton againstblack root rot caused by Thielaviopsis basico/a. Australian Plant Pathology 34(4): 499-507. http:/ /link.springer.com/article/10.1071%2F AP05089# Accessed May 2013Proprietary Data, 2000-2011 UC IPM. 2012. University ofCalifornia PestManagement Guidelines. Spinach. Downy Mildew. http://www.ipm.ucdavis.edu/PMG/r73210011l.html Accessed June 2013. USDA NASS. Chemical Use Surveys, 2006 and 2009. 

### http://www.nass.usda.gov/Surveys/Guide to NASS Surveys/Chemical Use/#description USDA, 2006-2010. NASS Crop Reporting Districts. Online: http://www.ers.usda.gov/briefing/arms/resourceregions/resourceregions.htm#nass. USDA, 2007. Census ofAgriculture. Online: http://www.agcensus.usda.gov/Publications/2007 /index.asp. Yourman, L. and E. Rim. 2004. Request for Emergency Exemption Use ofAcibenzolar-S-methyl (Actigard®) to Manage Iris Yellow Spot Virus ofOnions in Colorado (04-C0-10) [DP # 061402] Yourman, L. and J. Faulkner. 2009. Request for an Emergency Exemption for Acibenzolar-S-methyl (Actigard") to Manage Iris Yellow SpotVirus ofOnions in Colorado (09-C0-02; DP362704)



### 7APPENDIX A- Details ofAgricultural Pesticide Usage Map The maps ofagricultural pesticide usage at the Crop Reporting District (CRD) level are prepared by BEAD for use in the Environmental Fate and Effects Division (EFED) documents. These maps are used to help visualize where the pesticide being considered is most likely to be used and can be helpful in scenario selection and placing the exposure assessment in context. CRDs are boundaries created by USDA NASS which are aggregates ofcounties. Pesticide usage is displayed as average pounds (for the years 2007-2011) per 1,000 acres offarmland in a CRD to normalize for the variation in farmland between CRDs. Farmland acreage was obtained from USDA (2007). Farmland or "land in farms" is defmed as follows:
The acreage designated as "land in farms" consists primarily ofagricultural land used for crops, pasture, or grazing. It also includes woodland and wasteland not actually under cultivation or used for pasture or grazing, provided it was part of the farm operator's total operation. Large acreages of woodland or wasteland held for nonagricultural purposes were deleted from individual reports during the edit process. Land in farms includes CRP, WRP, FWP, and CREP acres. 1 Land in farms is an operating unit concept and includes land owned and operated as well as land rented from others. Land used rent free was reported as land rented from others. All grazing land, except land used under government permits on a per-head basis, was included as "land in farms" provided it was part of a farm or ranch. Land under the exclusive use ofa grazing association was reported by the grazing association and included as land in farms. All land in American Indian reservations used for growing crops, grazing livestock, or the potential of grazing livestock was included as land in farms. Land in reservations not reported by reservation, individual American Indians or nonNative Americans was reported in the name ofthe cooperative group that used the land. In many instances, an entire American Indian reservation was reported as one farm (USDA, 2007). Usage is based on private market surveys ofpesticide use in agriculture (Proprietary Data, 2007-2011). The survey data are limited to the states that represent the top 80-90% of acreage for the individual crops; therefore, use may be occurring in regions outside the scope of the survey. CRDs showing no usage of pesticides may be due to either the lack ofpesticide use in the region or non-participation in the agricultural surveys. In addition, across the years, there may be variations in the specific crops included in the CRD survey. This may result in a lower annual average for the CRD.
This map displays ratio data (i.e., average pounds per 1,000 acres offarmland) summarized at a very highlevel. Readers are strongly cautioned against trying to over interpret the map without examination of the underlying data. The underlying data may explain some ofthe many reasons that a Crop Reporting District may have a high value for a particular active ingredient such as significant acreage (compared with the CRD as a whole) ofa crop or crops with a high application rate and frequency ofapplication.
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. Scale and units of measurement do matter and may be different between maps.

1 CRP: Conservation Reserve Program; WRP: Wetland Reserve Program; FWP: Farmable Wetlands Program; CREP: Conservation Reserve Enhancement Program 

### 8