UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D
.C

. 20460 

## SEP 21 ZOl1

MEMORANDUM OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

SUBJECT: BEAD Chemical Profile for Registration Review: Cymoxanil (129106)
FROM: Leonard Yourman, Plant Pathologist Biological Analysis Branch

THRU: Katherine Stebbins, Biologist

## ~ Science Information and Analysis Branch Derek Berwald, Economist ()
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# ...:p Economic Analysis Branch 

## 'f' '**~** Biological and Economic Analysis Divisio (7503P) Amet Jones, Chief Biological Analysis Branch Diann Sims, Chief

# ;{).**1....n...,...c~~~v** Science Information and Analysis Branch Timothy Kiely, Chief

# ~**W\ ~**  Economic Analysis Branch '-'

# J Biological and Economic Analysis Division 503P) TO: Moana Appleyard, Chemical Review Manager Pesticide Reevaluation Division (7508P) Product Review Panel date: September 14,2011 INTRODUCTION 

## •

The purpose ofthis document is to convey usage information and a broad overview ofthe pest management roles ofpesticides that are beginning to undergo registration review. The anticipated audience consists ofthe team ofEPA staffcurrently evaluating the registration status ofcymoxanil, and eventually the general public
. This document
.builds upon the data already provided
. in the "Usage and Label Use Data Packages" that are also provided to Registration

1Reviewteams by BEAD. The document is based on information and data available to BEAD as ofAugust 2011. Cymoxanil is a locally systemic fungicide that penetrates plant tissue rapidly after application. The systemic characteristic allows for curative properties post-infection. Cymoxanil is in the chemical group cyanoacetamideoxime, which is listed as a Group 27 fungicide by the Fungicide Resistance Action Committee (FRAC). It is the only fungicide
.ofits chemical group. The specific mode ofaction or target site is unknown (FRAC, 2011). In general, cymoxanil is active on fungi that belong to the Peronosporales order and is mainly used to control late blight and other Phytophthora diseases, and downy mildews. 

### USE SITES Cymoxanil is registered for use onpotatoes, tomatoes, peppers; cucurbits, leafy vegetables (except Brassica group 4), bulb vegetables (bulb onion and green onion subgroup), grapes grown east ofthe Rocky mountains, caneberries (except in California), and hops (except in California). There are also Special Local Need (SLN) registrations for use onthe following crops: spinach, cabbage, Swiss chard, and table beets when they are grown.for seed. In addition, there is a SLN registration for use for commercial seed treatment for peas intended for export. 

### COMMON FORMULATIONS AND APPLICATION METHODS Cymoxanil is formulated as dry flowable and dust. One end-use product, Curzate® 60 DF, is used as a tank-mix with a protectant fungicide, such as a copper product. Another cymoxanilcontaining product is Tanos®, which includes 2S% cymoxanil and 2S% femoxadone. The third registered product is Evolve®, which is a potato seed-piece treatment containing 1 % cymoxanil, 2.S% thiophanate-methyl, and 6% mancozeb. Cymoxanil may be applied as a seed treatment to potato seed pieces and also to peas (as seeds for export only). Seedtreatments maybe made using slurry or mist seed treatment equipment. Foliar applications may be made using ground, aerial, and chemigation equipment. 

### USAGE Cymoxanil was registered for use onpotatoes in 1998. Over the 1998-2010 timeframe, usage on potatoes was highest in 1998 and 2000 and has generally leveled off(Figure 1). Usage overall has increased since the addition ofseveral new crops in 2004. Forthe most recent years of2008- 2010, cymoxanil usage in agriculture (excluding seed treatments) averaged approximately SO,OOO pounds for 400,000 treated acres (Proprietary Data 2008-2010). Seedtreatments were excluded throughoutthis analysis because usage data are only available for potatoes from 2009- 2010. However, as a general estimate, seed treatments onpotatoes accounted for less than 3% of the total acre treatments to potatoes in 2009 and 2010
. Cymoxanil is typically applied to foliage one time per year at a rate of0.12 pounds AI per acre.

2

### Fi e 1. Agricultural Cymoxamil Usage Pounds AI A lied 1998-2010 60,000



### o 00 en en .-t o o**~** .-t o o N Source: Proprietary Data, 1998-2010 N o o N rt'l o o N 

### ..,. o o N II') o o N \0 o o N ,.... o o N 00 o o N en o o N o .-t o N
Other includes lettuce, squash, onions, watermelons, caneberries, cantaloupes, wine grapes, and spinach • Other • Peppers • Pumpkins • Tomatoes • Cucumbers
• Potatoes



### During 2008-2010, the top crops in terms oftotal pounds ofactive ingredient applied were potatoes (49%), cucumbers (22%), tomatoes (8%), pumpkins (5%), and peppers (5%) (Figure 2). These crops were also the top 

### interms ofthe total acres treated.

Peppers

5%

Tomatoes 8%

Source: Proprietary Data, 2008-2010 

### Percent ofTotal Pounds AI A lied)

49%

Other crops (listed in order ofranking) includes: lettuce, squash, onions, watermelons, caneberries, cantaloupes, wine grapes, and spinach


### 3The states with the most agricultural usage in terms ofpounds AI applied are Michigan (19%), Washington (13%), Florida (11%), California (10%), Wisconsin (6%), and Idaho (5%) (Figure 3). These states were also the top in terms ofthe total acres treated. Fi ure 3. States with Hi hest Use (Percent ofTotal Pounds AI A lied)

Source: Proprietary Data, 2008-2010 BIOLOGICAL ASPECTS RELEVANT TO CYMOXANIL Resistance management strategies are described on both the Curzate® and Tanos®labels. FRAC identifies cymoxanil having a low to medium risk ofhaving resistance develop to it by a pathogen. Field resistance has not been reported, but some ofcymoxanil's target pathogens, such as Phytophthora infestans (the cause oflate blight ofpotato), are notorious for developing resistance to fungicides
. The language ofthe cymoxanillabels attempts to address the potential ofresistance development. The Curzate label states "DO NOT use Curzate® 60DF alone. Always tank

-mix with a labeled rate ofprotectant fungicide." Tanos®attempts to reduce resistance development by including two active ingredients, cymoxanil and femoxadone (a quinone outside inhibiting-QoI) fungicide (FRAC Group 11)
. Because ofthe two active ingredients, for some crops there are additional target diseases onthe label for Tanos than the label for cymoxanil as a single active ingredient product. Cymoxanil is the only Group 27 fungicide registered and, therefore, it may playarole in integrated disease management and resistance management programs where different fungicide chemistries are useful.
HISTORY OF BEAD ASSESSMENTS FOR CYMOXANIL There are no available prior BEAD assessments for cymoxanil.

4INFORMATION THAT MAY BE USEFUL FOR FUTURE WORK ON CYMOXANIL Obtaining additional information onthe following items would improve future BEAD assessments ofthe importance ofcymoxanil and may be required as part ofthe registration review ofthis pesticide. -Usage data for hops (ex
. total pounds applied, acres treated, typical use rates and number of applications) REFERENCES FRAC. 2011. Fungicide Resistance Action Committee. http://www.frac.info/frac/index.htm; http://www.frac.info/frac/publicationlanhangiFRAC%20Code%20List%202011-final.pdf (accessed September 8, 2011). Proprietary Data. 1998-2010.



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