UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

DEC 13 2012 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: BEAD Chemical Profile for Registration Review: Prometryn (080805) 

FROM: 

THRU: 

TO: 

Bill Phillips, Ph.D., AgronomisV"m / 

Biological Analysis Branch ~ _ 

JihadAlsadek,Ph.D.,Economist 

Science Information and Analysis Branch 

f;;w_ fr ~ 

Stephen Smearman, Economis~· /. _ ~ Economic Analysis Branch :~ 

Biological and Econom~ic Analysis rr-ivision (7503P) 

Arnet Jones, Chief 

Biological Analysis Br c 

Diann 

Science 

Sims, 

Information 

Chief ~ and Analysis Branch 

Timothy 

Economic 

Kiely, 

Analysis 

Chief 

Branch 

fl-\-

... ) J \f\1\ ~ 

Biological and Economic Analysis Division 503P) 

Christina Scheltema, Chemical Review Manager 

Risk Management and Implementation Branch 3 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: November 19,2012 

INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management roles of pesticides that are beginning to undergo registration review. The 

anticipated audience consists of the team of EPA staff currently evaluating the registration status 

of prometryn, 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 

1 
~ 

Review teams by BEAD. The document is based on information and data available to BEAD as 

ofNovember 1, 2012. 

The registration eligibility decision (RED) for prometryn was completed in February of 1996 at 

which time "[t]he Agency has determined that all uses of prometryn as currently registered will 

not cause unreasonable risk to humans or the environment and all uses are eligible for 

reregistration. " 1 

HISTORY OF BEAD ASSESSMENTS FOR PROMETRYN 

BEAD did not find any impact assessments or Section 18 Emergency Exemptions specifically 

for prometryn. 

HERBICIDE DISCUSSION 

Prometryn is a triazine herbicide in the Weed Science Society of America's group 5. This group 

of herbicides has the mechanism of action of inhibiting photosynthesis in photo system II. Weeds 

controlled by this herbicide are broadleaf with some annual grasses as well. 

Prometryn is applied by several methods and timing in terrestrial feed and food crops. In crops 

such as pigeon peas, prometryn is applied preemergence while in other crops, such as celery it 

can be used both preemergence and postemergence. In addition, in crops such as cotton, 

applications are made pre-plant incorporated, preemergence and/or post-directed. Following 

applications of prometryn, the duration for rotational crops restrictions can be significant. 

Several of these rotational restrictions are between 1 and 18 months depending upon the crop. 

Over the period of2007 and 2011 just under 95% of the total pounds ofprometryn active 

ingredient (lbs a.i.) were applied in cotton. In glyphosate resistant cotton there are some weeds, 

such as the morning-glory species, that are difficult to control with glyphosate. Without 

controlling weed species like morning-glory, growers will have problems harvesting due to the 

vining nature of morning-glory. Because this weed grows to the top of the cotton plant, 

wrapping itself around multiple plants, harvesting is made difficult. The use of prometryn plus 

trifloxysulfuron applied either post-directed or at layby is the best method for controlling 

morning-glory species and other difficult to control weed species. 2 

COMMON FORMULATIONS AND APPLICATION METHODS 

<::.. Prometryn is formulated as granules, emulsifiable, flowable concentrate, and soluble concentrate. 

Application methods include ground, aerial and via irrigation systems. 

1 Reregistration Eligibility Decision. 1996. http://www.epa.gov/oppsrrdl /REDs/0467.pdf 2 Dodds, D.M., M.T. Kirkpatrick, L.T. Barber, and D.B. Reynolds. 2008. Jor. of Cotton Sci. 12:311-317. 

http://journal.cotton.org. Cotton Foundation 

2 
/ 

USE SITES 

Agricultural Use Sites 

Prometryn is registered for use on the following agricultural use sites: carrots, celeriac, celery, 

celtuce, cilantro, cotton, dill, fennel, okra, parsley, pigeon peas, rhubarb, and leafy vegetables. 

Non-Agricultural Use Sites 

Prometryn has no registered non-agricultural use sites. 

USAGE 

Agricultural Use Sites 

Over the period 1998-2011, Figure 1 shows the use ofprometryn in terms oftotal pounds a.i. 

used. The use of prometryn was reached a maximum point in 2001. Overall there has been a 

declined in use of this herbicide. The data available to BEAD only covers carrots, celery, com, 

cotton and sweet com, fallow, and rice even though this chemical is registered for more crops. 

Figure 1. Agricultural Usage Data for Prometryn in Pounds a.i. on All Crops (1998-2011) 

.,;. 

"C "' c 

~ 

0 

a.. 

DO 

Cl'\ 

Cl'\ 

..... 

Cl'\ 0 Cl'\ 0 Cl'\ 0 ..... N 

Source: Proprietary Data, 1998 -2011 

..... N M 0 0 0 

0 0 0 N N N 

<;t U") \D ...... DO Cl'\ 0 

0 0 0 0 0 0 ..... 0 0 0 0 0 0 0 N N N N N N N 

Years 

..... 

..... 

0 

N 

For the period 1998-2011, an annual average of 158,000 lbs a.i. were used to treat 1.4 million 

acres for an overall average application rate of 0.1 lbs. a.i. per acre, and for the period 2007-2011 

about an annual average of687,000 lbs a.i. were used to treat 902,000 acres for an average 

application rate of 0.8 lbs. a.i. per acre. 

3 
During 2007-2011, the crops with the most use in terms of total pounds of active ingredient and 

total area treated are cotton and celery. 

On average, the states with the most agricultural usage in terms of pounds a.i. applied are Texas 

(33%), Georgia (20%), North Carolina (12%), and California and Tennessee (8% each). The 

most agricultural usage in terms of total area treated (TAT) in acres are Texas (38%), Georgia 

(19%), North Carolina (11 %), and Tennessee (9% each). (Proprietary Data, 2007-2011). 

CONCLUSION 

Overall the use of prometryn has declined; however based on the amount of the herbicide used 

annually there seems to be some important uses for celery and cotton. 

REFERENCES: 

Proprietary Data, 1998-2011 

Proprietary Data, 2006-2010 

USDA, 2006-2010. NASS Crop Reporting Districts. 

http://www.ers.usda.gov/briefing/anns/resourceregions/resourceregions.htm#nass. 

USDA, 2007. Census of Agriculture. 

http://www .agcensus. usda. gov /Pub Iications/2007 /index. asp. 

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Appendix 

Another measure of usage is the use intensity. In this analysis, the use intensity is expressed as 

the pounds a.i. applied per 1000 acres of land in farms. This differs from the application mte, 

which is expressed as the pounds a.i. applied per treated acre. The average application rate of 

0.8 lb a.i. per acre is equivalent to 800 lbs per 1000 treated acres. The maximum use intensity is 

about 40 lbs a.i. per 1000 acres of farm land. The figure spatially represents prometryn's use in 

the US and the most intense use occurs in Georgia for cotton. 

Prometryn Usage by Crop Reporting District (2006-2010) 

Prometryn • Use (2006-20 I 0) by Crop Reporting 

District Avenge Pounds per 1,000 Acres of 

Farmland 

.. <1 

.. 1-3 

c:=J 4-8 

c=J 9-15 

16-44 

This is a map of agricultural pesticide usage at the Crop Reporting District (CRD) level prepared by BEAD 

for use in the Environmental Fate and Effects Division 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 of counties (USDA, 2010). Pesticide usage is displayed as average pounds (for the years 2006-

201 0) per 1,000 acres of farmland 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 of agricultural 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 

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the edit process. Land in farms includes CRP, WRP, FWP, and CREP acres. 

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 of a 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 of the cooperative group that used 

the land. In many instances, an entire American Indian reservation was reported 

as one farm (2007 Census of Agriculture, USDA). 

Usage is based on private market surveys of pesticide use in agriculture (Proprietary Data, 2006-2010). 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 of pesticide 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 of farmland) 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 of the 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) of a crop or crops with a high application rate and frequency of application. 

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. 

Sources: 

Proprietary Data. 2006-2010 

USDA, 2006-2010. NASS Crop Reporting Districts. 

USDA, 2007. Census of Agriculture. 

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