UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JUL Ot5 l012 

MEMORANDUM 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: 

FROM: 

BEAD Chemical Profile for Registration Review: Foramsulfuron (122020) 

Sunil Ratnayake, Biologist /1 .. A X~ _ () . 

Biological Analysis Branch L VW4f\ T\ ~ 

THRU: 

Jihad Alsadek, Economist ~ 1f--r yf-~ Science Information and Analysis Branch 

Stephen Smearman, Economist 0 n J ..... ~ Economic Analysis Branch . . 

Biological and Economic Analysis Division (7503P) 

Amet Jones, Chief /] ~ 1 

Biological Analysis Bran~ lj 

Diann Sims, Chief 

Science Information and Analysis Branch 

Economic 

Timothy Kiely, 

Analysis 

Chief 

Branch 

~ V _ J. \Nl ~ Biological and Economic Analysis Division 3P) 

TO: Jose Gayoso, Chemical Review Manager 

Risk Management and Implementation Branch 2 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel date: May 9, 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 foramsulfuron, 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 

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

of May 2, 2012. 

Foramsulfuron was initially registered in 2002 (EPA, 2002). Foramsulfuron belongs to the 

sulfonylurea herbicide family and it inhibits the activity of acetolactate synthase (ALS) enzyme. 

It is a selective herbicide applied as a post-emergence treatment to control annual and perennial 

grass and broadleaf weeds mainly in field com, sweet com, and non-agricultural sites described 

below. Foramsulfuron is absorbed by leaves and roots of susceptible plants and provides very 

effective weed control at very low rates. 

COMMON FORMULATIONS AND APPLICATION METHODS 

Foramsulfuron is formulated as an emulsifiable concentrate. Ground applications with tractor 

mounted ground sprayers and aerial applications are recommended. 

USE SITES 

Agricultural Uses 

Foramsulfuron is registered for use on com and sweet com. 

Non-Agricultural Uses 

Foramsulfuron is registered for use on ornamental turf, domestic dwellings (outdoor), camp sites, 

schools (outdoor), and roadsides. 

USAGE 

Agricultural 

From 2002-2010, the annual total agricultural usage offoramsulfuron averaged approximately 

17,000 pounds of active ingredient (a.i.) for 632,000 treated acres with an overall application rate 

of0.03 lbs. a.i. per acre. Less than one percent of the com crop is treated annually. 

During this timeframe, the crop with the most use in terms of total pounds of active ingredient 

applied and total acres treated is com (nearly 100%). Less than 0.1 percent is used on sweet 

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

total acres treated are Nebraska (15%), Iowa (13%), Illinois (12%), and Indiana (11 %). 

USE TRENDS 

Figure 1 shows the trend in terms oftotal pounds offoramsulfuron used on com. There was no 

reported use in 2000 and 2001 because 2002 was the initial year of registration; reported usage 

from 2002 through 2010 indicates a continuous decline in use. During the last three years, 2008-

2010, the application rate was still 0.03 lbs. a.i. per acre. 

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Figure 1. Agricultural Usage Data of Foramsulfuron on Corn, 2002-2010 

PoundsA.I. 

2002 2003 2004 2005 2006 2007 2008 2009 2010 

Years 

Source: Proprietary Data, 2002 -2010 

Foramsulfuron Agricultural Usage by Crop Reporting District 

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

the pounds a.i. applied per acre of land in farms. This differs from the application rate, which is 

expressed as the pounds a.i. applied per treated acre. Figure 2 spatially represents foramsulfuron 

use intensity on com. The highest use intensity was observed in Idaho, Nebraska, and Indiana 

as indicated by the red color (Fig. 2). The data indicate that reported use in a given Crop 

Reporting District (CRD) is driven by the reported number of pounds applied per acre ofland in 

farms extrapolated over the number of growers in a particular CRD. So the use of 

foramsulfuron by a single user in an CRD that has a high number of projected users but a small 

number of total acres grown for a crop that might be treated with foramsulfuron may appear on 

the map as if there is very intense use in a CRD when in fact the use may be for only a very 

small number of acres. 

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Figure 2. Foramsulfuron Usage by Crop Reporting District (2006- 2010) 

Average Pounds Per 

1,000 Acres of Fannland 

. 0.00-002 

0.03-0.05 

c:::::J o.OS-0.12 

0.13- 0.19 

. 0.20-035 

This is a map of agricultural pesticide usage at the Crop Reporting District (CRD) level. CRDs are 

boundaries created by USDA NASS which are aggregates of counties (USDA, 2010). Pesticide usage is 

displayed as average pounds (for the years 2006-2010) 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). 

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. 

Non-Agricultural 

The main non-agricultural use of foramsulfuron is on golf courses. The reported amount of 

forainsulfuron used on golf courses approximately doubled from 500 lbs. a.i. in 2004 to 1,000 

lbs. a.i. in 2006. Less than 500 lbs. a.i. was reportedly used for institutional turf, landscape, and 

lawn care operators (LCOs) from 2004 to 2006. 

BIOLOGICAL ASPECTS RELEVANT TO FORAMSULFURON 

Foramsulfuron is a sulfonylurea herbicide and the mode of action of this class of herbicide is 

inhibition of acetolactate synthase (ALS) enzyme. Many weed species resistant to ALS inhibitors 

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have been reported in the United States. Presence of annual bluegrass (Poa annua) biotypes 

specifically, with resistance to bispyribac-Na, foramsulfuron, imazaquin, and trifloxysulfuronsodium has been reported in the State of Alabama (Heap et al. 2012) The control of weed 

species resistant to foramsulfuron can be achieved by tank mixing a compatible registered 

herbicide with a different mode of action to foramsulfuron. Since the introduction of Roundup 

ready com in 1988, the acreage of Roundup ready com has increased significantly. Therefore, 

the observed reduction offoramsulfuron usage on com from 2002 to 2010 may be due to the 

increase of glyphosate usage in Roundup ready com production in the United States. 

HISTORY OF BEAD ASSESSMENTS FOR FORAMSULFURON 

A search of BEAD's document database did not reveal any previous BEAD assessments. 

DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ON FORAMSULFURON 

Obtaining additional information on typical foramsulfuron use in the non-agricultural sector 

would improve future BEAD assessments on foramsulfuron and may be necessary as a part of 

the registration review of this pesticide. Requested data should include, but not be limited to 

application timing, application rate, application method, and application frequency. 

CONCLUSION 

The importance offoramsulfuron applied as a post-emergence treatment to control annual and 

perennial grass and broadleaf weeds mainly in com and non-agricultural sites has been in 

decline. While foramsulfuron provides an effective weed control at very low rates in corn, it 

appears to be losing market share, possibly to glyphosate products. 

REFERENCES 

Heap, I, H. Glick, L Glasglow, and W. Vencill. 2011. Herbicide Resistant Weeds by Country 

and Site of Action. 2011. http://www.weedscience.org/summary/countrysummary.asp. 

Kline and Company, Inc., 2004-2006. 

Proprietary Data, 2002-2010. 

USEPA. 2002. Pesticide Fact Sheet. Foramsulfuron. 

http://www .epa. gov I opprdOO 1 /factsheets/foramsulfuron. pdf . 

USDA, 2006-2010. NASS Crop Reporting Districts. 

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

USDA, 2007. Census of Agriculture. 

http:/ /www.agcensus. usda.gov/Publications/2007 /index.asp .. 

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