UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

AUG 18 2015 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: BEAD Chemical Profile (BCP) for Registration Review: Tebuconazole (128997) 

FROM: 

THRU: 

Tara Chandgoyal, Ph.D., Plant Pathologist 

Biological Analysis Branch 

Don Atwood, Ph.D., Entomologist 

Science Information and Analysis Branch 

Andrew Lee, Economist 

Economic Analysis Branch 

!<MA~ 

J)-~/Jn t.U;;;; •• // 

Biological and Economic Analysis Division (7503P) 

Arnet Jones, Chief 

Biological Analysis Br 

Diann Sims, Chief M . Science Information and Analysis Branch 

Timothy Kiely, Chief (VJ OM.A,(J~Uu_;j fv< {i mo~ ~(£ CJ 

Economic Analysis Branch 

Biological and Economic Analysis Division (7503P) 

TO: Jose Gayoso, Chemical Review Manager 

Kevin Costello, Chief 

Risk Management and Implementation Branch II 

Pesticide Re-evaluation Division (7508P) 

Peer Review Panel date: August 5, 2015 

Page 1 of9 
SUMMARY 

Tebuconazole is a systemic fungicide with protective, curative, and eradicant properties. These 

antifungal properties result in fungal disease control on various crops (barley, wheat, peanuts, 

and many others). Tebuconazole belongs to group 3 ofFRAC classification of fungicides 

(FRAC, 2015). There is medium risk of developing resistance in fungal plant pathogens against 

tebuconazole (FRAC, 2015). According to available proprietary information, the highest usage 

of tebuconazole, in terms of total pounds applied, was in Georgia and North Dakota. 

Tebuconazole use has generally been increasing since 2008, both in terms of pounds used and 

acres treated. This may be due to increased disease pressure of foliar and seed-borne diseases on 

different crops. 

INTRODUCTION 

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

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

The BCP includes available public and/or private use and usage data for tebuconazole and a 

general discussion of biological aspects, intended to describe the role of this chemical in pest 

management. Additional information on use is available in the Tebuconazole Label Data Report 

provided in the public docket for this chemical. Information provided in this BEAD Chemical 

Profile (BCP) may be used by stakeholders (e.g., users and registrants), Office of Pesticide 

Programs (OPP) risk and benefit assessors, and OPP risk managers, and the general public 

during the Registration Review process of this pesticide. 

AGRICULTURAL USE SITES 

Tebuconazole is registered for use on asparagus, barley, beans, beans (dried-type), beets, 

brassica (head and stem vegetables), bulb vegetables, field com, popcorn, sweet com, cotton, 

cucurbit vegetables, fruiting vegetables (except okra), garlic, grapes, hops, leek, oats, okra, dry 

bulb onions, green onions, peanuts, pome fruits, rye, shallot, soybeans, stone fruits, 

subtropical/tropical fruit, sunflower, tree nuts, turnip, and wheat. 

NON-AGRICULTURAL USE SITES 

Non-agricultural use sites which are labeled for tebuconazole application include industrial 

adhesives, industrial coatings, golf course turf, grasses grown for seed, metalworking cutting 

fluids, ornamentals (grasses, trees, shrubs, vines, and flowering plants), plastic, specialty 

industrial products, and wood protection treatments. 

FORMULATIONS AND APPLICATION METHODS 

Tebuconazole is formulated as a granular, pelleted/tableted, wettable powder, water dispersible 

granules, emulsifiable concentrate, flowable concentrate, soluble concentrate, and solution-ready 

to use (RTU). Application may be made using either ground or air equipment and as a seed 

treatment. 

Page 2 of9 
HISTORY OF BEAD ASSESSMENTS FOR TEBUCONAZOLE 

There are no benefits assessments or recent Section 18 Emergency Exemption Requests for 

tebuconazole in the BEAD official record database. An emergency exemption may indicate that 

there is a need for a particular chemical that is not registered for use on a particular site. An 

emergency exemption request may yield information about a particular chemical's importance or 

value that is not found in other EPA records. However, a lack of Section 18 assessments by 

BEAD does not specifically indicate the relative importance of the chemical. 

TEBUCONAZOLE USAGE 

Agricultural Usage 

Usage of tebuconazole and number of acres treated was relatively stable from 1998 to 2008. 

Since 2008, there has been a significant increase in both total area treated and pounds a.i. 

applied. The increase in pounds a.i. applied and acreage treated was 40% and 71 %, respectively. 

This increase after 2008 reflects tebuconazole usage as a seed treatment for wheat. 

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__.__Total Area Treated 

- •- Pounds Al Applied 

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Figure 1. National Tebuconazole Usage (Pounds A.I. and Total Area Treated) from 1998 to 

2013. . 

Source: Proprietary Data, 1998-2013 

A review of total tebuconazole usage data for the last 4 years indicates that the primary use sites 

are peanuts and wheat, accounting for approximately 87% of pounds applied and 79% of total 

acres treated (Table 1 ). Average tebuconazole application rates range from 0.032 to 0.189 lb a.i. 

per acre for the major use sites in the United States. Highest average application rate across all 

registered use sites is 0.251 lb a.i. per acre for sugar beets but only reflects a minor use site with 

Page 3 of9 
application of less than 500 lbs and 2,000 acres annually. Lowest average application rate across 

all registered crops is 0.032 lb a.i. per acre for winter wheat and reflects seed treatment 

tebuconazole application. 

Peanuts 

Spring Wheat 219 

Winter Wheat 192 

Soybeans 23 

Wine Grapes 21 

Pecans 15 

42 

24 

21 

3 

2 

2 

2010-2013. 

% of Total 

Tebuconazole 

Treated Acres 

14 

37 

41 

2 

Avg AI 

Rate 

0.189 

0.041 

0.032 

0.108 

0.106 

0.118 

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

Source: Proprietary Data, 20 I 0-20 I 3 

In contrast to the usage data shown in Table 1, crops with highest tebuconazole usage in terms of 

Percent Crop Treated (PCT) as determined by the Screening Level Usage Analysis (SLUA) 

(BEAD, 2015), are garlic, peanuts, cherries, grapes, watermelon, wheat (seed treatment), 

peaches, and nectarines (Table 2). No other crop exceed an average 5 PCT. Nevertheless, the 

SLUA data does indicate that tebuconazole has important usage on crops other than those with 

greatest pounds applied. 

Treated \Vith Tebuconazole. 

Maximum 

Garlic 95 

Peanuts 45 55 

Cherries 30 45 

Grapes 25 35 

Watermelon 15 30 

Wheat (seed treatment 15 20 

Peaches 10 25 

Nectarines IO 20 

Source: BEAD 2015 SLUA 

Table 3 indicates the states with a i;ninimum of five percent usage of tebuconazole in terms of 

total tebuconzaole pounds a.i. applied in the United States. Georgia and North Dakota account 

for 43 percent of total pounds of tebuconazole applied and 33 percent of total acres treated with 

tebuconazole. Of states with highest tebuconazole usage, Florida has the highest application rate 

(0.185 pounds a.i. per acre) and Texas the lowest (0.037 pounds ai per acre). 

Page 4 of9 
Georgia 227 

North Dakota 164 

Florida 68 

Alabama 59 

Minnesota 55 

Kansas 47 

Texas 45 

California 44 

25 

18 

7 

6 344 

6 974 

5 1,080 

5 1,219 

5 490 

9 

24 

3 

2 

7 

7 

8 

3 

Avg Al 

Rate 

0.171 

0.047 

0.185 

0.174 

0.057 

0.044 

0.037 

0.092 

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

Source: Propriet01y Data, 2010-2013 

According to proprietary data, total acres treated with tebuconazole are evenly split between seed 

treatment and foliar application (Table 4). Seed treatment accounts for approximately I percent 

of tebuconazole pounds applied but 50 percent of total acres treated. Ground application 

(broadcast, banded, and spot treatment only) represents 80 percent of total tebuconazole pounds 

applied and 3 8 percent of total acres treated. Aerial application accounts for 19 percent of total 

tebuconazole pounds applied and 12 percent of total acres treated. 

Ground (broadcast, banded, 

and s ot treatment 

Aerial 

Seed treament 

745 

175 

7 

80 

19 

0.8 

5,583 38 

1,705 12 

7,280 50 

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

Source: Proprietary Data, 2010-2013 

Geographic Distribution of Tebuconazole Use 

Tebuconazole has widespread reported usage in the United States (Figure 3). States with highest 

pounds used per 1,000 crop acres grown include Georgia, South Carolina, Alabama, and Florida. 

The greatest use in the Southeastern U.S. is primarily related to peanut production which has a 

high percent crop treated and a relatively high application rate, both of which contribute to a high 

intensity of use relative to cropped acres. Tebuconazole usage in the central U.S. largely reflects 

usage on wheat and the lower application rate associated with seed treatment. Usage in 

California and Michigan reflect usage on wine grapes and cherries, respectively. 

Page 5 of9 
Pounds Active Ingredient 

per 1,000 Crop Acres Grown 

0No0ata 

LJ <1 

1 -9 

-10- 15 

- >15 

Figure 2. Annual average agricultural use intensity of tebuconazole (2008-2012). 

Source: Proprietary Data, 2008-20 I 2 

Please refer to Appendix A (below) for additional details on the scope and context of this map. 

Non-Agricultural Usage 

According to the most recent data available, tebuconazole usage in the Professional Ornamental 

and Turf market and Consumer market was 38,000 pounds and 10,000 lbs, respectively, in 2011 

(Proprietary Data, 2012). 

BIOLOGICAL ASPECTS RELEVANT TO TEBUCONAZOLE 

Tebuconazole inhibits sterol demethylation in fungi, causing fungal cell wall collapse and 

inhibition of hyphal growth. Tebuconazole is a systemic fungicide with protective, curative, and 

eradicant properties. These antifungal properties result in fungal disease control on various crops. 

Tebuconazole belongs to fungicide group 3 (SBI: Class I, such as fenbuconazole, myclobutanil, 

propiconazole, prothioconazole, tetraconazole and some others) of FRAC classification of 

fungicides (FRAC, 2015). There is medium risk of developing resistance in fungal plant 

pathogens against tebuconazole (FRAC, 2015). Tebuconazole can be used as a stand-alone 

Page 6 of9 
fungicide or in combination/alternation with fungicides with different modes of action (such as 

azoxystrobin, pyraclostrobin). Since 2008 its use has increased as result of use as a seed 

treatment on wheat. We do not know the reasons for its sudden increase since 2008. 

ROLE OF TEBUCONAZOLE IN PEST MANAGEMENT 

Tebuconazole is predominantly used on peanuts and wheat. Highest percent of total pounds 

applied was in Georgia followed by North Dakota. In Georgia it is mainly used on peanuts and in 

North Dakota it is used on wheat to control fungal pests. It can be applied alone or in 

combination with other fungicides (such as azoxystrobin, pyraclostrobin). On peanuts, it is 

labeled for controlling soil-borne (Sclerotinia stem and pod rot, Rhizoctonia limb rot and pod 

rot) and foliar (early leaf spot, late leaf spot, leaf rust, web blotch and pepper spot) fungal 

diseases. High percent crop treated suggests that there may be limited options and relatively high 

benefits of tebuconazole use on peanuts. On wheat, it is labeled for controlling leaf rusts and 

stem rust caused by Puccinia spp., head blight or scab caused by Fusarium spp. The percentage 

of the wheat crop treated with tebuconazole is not as high as peanuts. This may be because 

propiconazole and prothioconazole are also used on wheat to control Fusarium head blight, a 

dominant fungal disease of wheat. .Highest percent of crop treated with tebuconazole was garlic 

followed by peanuts, cherries and grapes suggesting high benefits of using tebuconazole on these 

crops. On garlic, rust disease can cause crop failure and tebuconazole is highly effective in 

controlling the disease (Koike et al., 2001 ). On peanuts, tebuconazole is used to control leaf spot 

disease and soil-borne diseases (white mold and Rhizoctonia limb rot) (Kemerait et al., 2008). 

On cherries, tebuconazole is used to control leaf spot and powdery mildew diseases (anonymous, 

2013; Jones et al., 1993) and on grapes, tebuconazole controls powdery mildew disease. 

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

TEBUCONAZOLE 

The Agency currently does not have important non-agricultural information on tebuconazole. 

Obtaining the following information for all registered non-agricultural sites may improve future 

assessments conducted by the Agency related to the use and importance of tebuconazole. 

• Total pounds active in~edient applied 

• Percent crop/site treated 

• Application rates: typical and maximum 

• Frequency of application 

• Application Intervals 

• Methods of application 

• Target or niche pests 

• Efficacy information/product performance 

In addition, obtaining the following usage information may improve future assessments 

conducted by the Agency related to the use and importance of tebuconazole in agricultural 

settings: 

1) Typical application timing in each registered crop. 

Page 7 of9 
2) If more than one application is typically made, the typical re-application interval (per 

crop). 

3) Recent resistance reports for tebuconazole in populations of important target pests, in 

particular cases of cross-resistance to other fungicides. 

REFERENCES 

Anonymous. 2013. 

https://das.wsu.edu/news/storv/2013/04/01/Powdery Mildew of Cherry New Fungicide Tool 

and Resistance Management Guidelines. Accessed on August I 0, 2015. 

BEAD. 2015. Screening Level Usage Analysis (SLUA) for Tebuconazole. 

(Accessible in the tebuconazole registration review docket at www.regulations.gov]. 

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

2015-finalC2AD7AA36764.pdf?sfvrsn=4. Accessed on July 25, 2015 

Jones, AL., Ehret, GR., Garccia, SM. 1993. Control of cherry leaf spot and powdery mildew on 

sour cherry with alternate-side application of fenarinol, myclobutanil and tebuconazole. Plant 

Disease 77:703-706. 

Kamerait, BK., Brenneman, T., Culbreath, A. 2008. The University of Georgia, College of 

Agriculture and Environmental Sciences. 2008 Peanut Update. 

http://www.caes.uga.edu/commodities/fieldcrops/peanuts/2008peanutupdate/diseases.html 

Koike, S.T., Smith, R.F., Davis, R.M., Nunez, J.J., Voss, R.E. 2001. Rust continues to threaten 

California garlic crop. California Agriculture (September-October, 2001 ): 35-39. 

Proprietary Data. 1998-2013. Data on use collected nationally from farmers by a private 

marketing firm using statistically valid survey methods. 

Proprietary Data. 2008-2012. Data on use collected nationally from farmers by a private 

marketing firm using statistically valid survey methods. 

Proprietary Data. 2010-2013. Data on use collected nationally from farmers by a private 

marketing firm using statistically valid survey methods. 

Proprietary Data. 2012. Data collected nationally for non-agricultural use by a private 

marketing firm using statistically valid survey methods. 

Schilder, A. 2012. Fungicide update for grapes. 

http://grapes.msu.edu/uploads/files/Newsletters/2012/ AprilFungicide update for grapes 201_2.pdf. Accessed August 10, 2015. 

APPENDIX A 

Page 8 of 9 
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 ail 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 diffe~ent. 

Page 9 of9