UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

DEC 02 Z014 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Myclobutanil (128857) 

FROM: 

THRU: 

Tara Chandgoyal, Ph. D., 

Plant Pathologist 

Biological Analysis Branch 

Claire Paisley-Jones, Biologist L.--f'CY"~ Science Information and Analysis Branch { 

Elizabeth Hill, Economist 

Economic Analysis Branch 

Biological and Economic Analysis Division (7503P) 

Arnet Jones, Chief 

Biological Analysis Branch 

Diann Sims, Chief 

Science Information and Analysis Branch 

Timothy 

Economic 

Kiely, 

Analysis 

Chief 

Branch 'J 

~ J ~ 

Biological and Economic Analysis Division 7 3P) 

TO: Khue Nguyen, Chemical Review Manager 

Pesticide Re-evaluation Division (7508P) 

Peer Review Panel date: November 5, 2014 

1 
SUMMARY 

Myclobutanil fungicide belongs to the triazoles chemical group of De-Methylation Inhibitors 

(DMI) fungicides. It belongs to group 3 of Fungicide Resistance Action Committee (FRAC) 

based on mode of action of fungicides. It is registered for use on berries, grapes, nut trees, pome 

fruit, stone fruit, tropical fruit, flavoring and spice crops, cucurbits, fruiting vegetables, leafy and 

stem vegetables, beans, okra, asparagus, and cotton to control and/or manage fungal disease. In 

recent years (2008-2012) approximately 120,000 lbs ofmyclobutanil were applied annually to 

2,000,000 acres. The vast majority ofmyclobutanil was applied to grapes (45% oftotal pounds 

applied), and apples (20% of total pounds applied). The remaining 35% of total pounds of 

myclobutanil were applied in much smaller quantities to over 25 other crops. 

INTRODUCTION 

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

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

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

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

Additional information on use is available in the myclobutanil PRD Label Data Report. 

Information provided in this BEAD Chemical Profile (BCP) may be used by stakeholders (e.g., 

users and registrants), OPP risk assessors, and OPP risk managers, and the general public during 

the Registration Review process of this pesticide. 

HISTORY OF Myclobutanil and BEAD PRODUCTS 

No Section 18 requests have been submitted for myclobutanil in the past ten years. Note that a 

lack of recent Section 18 requests should not be interpreted as a lack of benefits associated with 

this chemical. 

COMMON FORMULATIONS AND APPLICATION METHODS 

Myclobutanil is formulated as a granular, dry flowable, wettable powder, emulsifiable 

concentrate, soluble concentrate, pressurized liquid, and ready to use. This chemical is 

formulated as a granular, dry flowable, wettable powder, emulsifiable concentrate, soluble 

concentrate, pressurized liquid, and ready to use. 

USE SITES 

Agricultural Use Sites 

Agricultural use sites of myclobutanil include: berries, grapes, nut trees, pome fruit, stone fruit, 

tropical fruit, flavoring and spice crops, cucurbits, fruiting vegetables, leafy and stem vegetables, 

beans, okra, asparagus, and cotton. 

2 
Non·Agricultural Use Sites 

Non·agricultural uses of myclobutanil include: various trees, grasses, and ornamentals. 

MYCLOBUTANIL USAGE 

Agricultural Usage 

Between 1998 and 2012 an average of approximately 145,000 pounds of myclobutanil were 

applied annually over an average of 1,610,000 acres (Fig. 1 ). During this time period both the 

total acres treated and total pounds applied have fluctuated somewhat from year to year, overall 

yearly pounds AI applied has decreased slightly, while total acres treated has slightly increased. 

250,000 

Total Pounds 

AI Applied 

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Total Acres 

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Figure 1. Myclobutanil Total Acres Treated and Total Pounds A.I. Applied (2002-2012). 

Source: Proprietary Data, 2002-2012 

Between 2008 and 2012 approximately 120,000 lbs ofmyclobutanil were applied annually to 

2,000,000 acres. The vast majority ofmyclobutanil was applied to grapes (45% oftotal pounds 

applied), and apples (20% of total pounds applied). The remaining 35% of total pounds of 

myclobutanil were applied in much smaller quantities ( < 8,000 average lbs AI per year) to over 

25 other crops (Table 1). In 2011, there was a spike in acres treated with myclobutanil. This 

was due to cotton seed treatment in Texas that was used from a weather-induced fungal disease. 

The rate for myclobutanil seed treatments on cotton seed was 0.0003 lbs of active ingredient per 

acre, whereas for foliar applications it is 0.09lbs active ingredient per acre (1998-2012). 

3 
T a bl e 1 . M I b t tyc o uam 'I U se on T C op rops: A verage A I R .. a t e, 2008 -2012 

Crop Average Pounds Average Total Acres Average A.L Rate 

A.L/yeaF Treated /year * Obs a.i./acre) 

Grapes 52,000 502,000 0.104 

Apples 24,000 210,000 0.116 

Other** 3-8,000. 25 - 880,000" 0.004- 0.500" 

**Other crops: Apricots, Artichoke, Asparagus, Beans, Caneberries, Cantaloupes, Cauliflower, 

Cherries, Cotton, Cucumbers, Dry Beans/Peas, Lettuce, Peaches, Pears, Pecans, Peppers, Pistachios, 

Plums/Prunes, Pumpkins, Soybeans, Spinach, Squash, Strawberries, Sugar Beets, Tomatoes, Walnuts, 

Watermelons. 

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

• For Other crops: Avg. Lbs., Avg. TAT, and Avg. AI Rate show the range of average annual values for all 

"other'' crops. 

Source: EPA Proprietary Data, 2008-2012 

Another measure of pesticide usage, percent crop treated, indicates the potential importance of a 

chemical to a crop. Ofthe top crops uses a considerable portion of grapes (30%) and apples 

(35%) are treated with myclobutanil. Similarly, a sizable percentage of several crops (listed as 

"Other" in Table 1, above) including artichokes (65%), apricots (40%), strawberries 30%), and 

cherries (25%) are treated with myclobutanil. The percent crop treated of all observed crops from 

2004 to 2012 can be found in the SLUA. 

Table 2 shows usage in terms of percent of total pounds a.i applied by state during the same time 

period represented in Table 1 (2008-2012). During this time period, the majority of 

myclobutanil (65% oftotal pounds AI) was applied in California. California's usage is followed 

distantly by Washington (10%), Michigan (5%), and 29 other states (Table 2). 

Table 2. States with Highest Use of 

Myclobutanil- Percent of Total Pounds 

AI . . A "pp11e r dB e tw een 2008 -2012 . 2008-2012 

Average Annual= 120,000 lbs A.J. 

State o/o Lbs 

California 65 

Washington 10 

Michigan 5 

Other* 20 

*Other states: NY, TX, NC, AK, VA, FL, OR, JK, 

OH, GA, NM, IN, MI, MD, CT, WV, AL, TN, MO, 

SC, AZ, IL, OK, lA, MA, LA, WI, ID, KS 

Source: Proprietary Data, 2008-2012 

Non-Agricultural Usage 

Myclobutanil is used in small quantities by lawn care operators, and on golf courses, institutional 

turf facilities, and turf farms. Its use by landscape contractors, on the other, is far more 

significant. In 2011, myclobutanil was the leading active ingredient in the segment, accounting 

4 
for 65 percent of poundage applied, or nearly 70,000 pounds of active ingredient (Proprietary 

Data2011). 

Geographic Distribution ofMyclobutanil Usage 

The map below shows myclobutanil use intensity in terms of pounds A. I. applied per 1 ,000 acres 

of crop area grown in each state. While the majority of myclobutanil is applied in California, 

Washington, and Michigan (Table 2), use intensity is higher in the north eastern states 

Connecticut, New Jersey, and Massachusetts where there are fewer total agricultural acres. 

Pounds Active Ingredient 

per 1 ,000 Crop Acres Grown 

c:::J No Data 

0<0.1 

c:::Jo.1-1 

1 -10 

- >10 

Figure 1. Annual average agricultural use intensity of myclobutanil (2008-2012). 

More information about this map is presented in Appendix A. 

5 
BIOLOGICAL ASPECTS RELEVANT TO MYCLOBUTANIL 

Myclobutanil fungicide belongs to the triazoles chemical group of De-Methylation Inhibitors 

(DMI) fungicides. It belongs to group 3 of Fungicide Resistance Action Committee based on 

mode of action of fungicides (FRAC, 2013). There are big differences in the activity spectra of 

DMI fungicides (FRAC 2013). Resistance in many fungi against DMI fungicides is known and it 

is generally accepted that cross resistance is present between DMI fungicides active against the 

same fungus (FRAC, 2013). These fungicides have medium risk of resistance development in 

fungi (FRAC, 2013) and resistance management is recommended (FRAC, 2013). The resistance 

in fungi against a fungicide can be prevented by premixing it with a fungicide having a different 

mode of action or alternating it with fungicides with different modes of action. 

ROLE OF MYCLOBUTANIL IN PEST MANAGEMENT 

Myclobutanil is registered for the control of many fungal diseases on various crops. On grapes, it 

is labeled for controlling anthracnose, black rot and powdery mildew diseases. On apples, it is 

labeled for controlling powdery mildew, rust and scab (pre-bloom, bloom and post-infection) 

diseases. Myclobutanil appears to be effective in controlling fungal diseases on the registered 

crops. California is the largest producer of grapes and accounts for 65% of total usage of 

myclobutanil in the United States. Based on use and usage it appears to play an important role in 

the control of fungal diseases in the production of grapes, apples, almonds, tomatoes, cherries 

and many other crops. 

REFERENCES 

BEAD. 2014. Myclobutanil Screening Level Usage Analysis. Biological and Economic 

Analysis Division, Office of Pesticide Programs, US Environmental Protection Agency. 

FRAC. 2013. Accessed on October 11,2014. 

http:/ /www.frac.info/publication/ anhang/FRA C%20Code%20 List%2020 13-final. pdf 

Proprietary Data. 1998-2012. (pesticide usage data) 

Proprietary Data. 2011. (pesticide usage data) 

6 
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 ai/ A). 

The data used to make 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, 2008-2012). These surveys 

cover about 60 crops and are 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 crops. 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. 

7