UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MAY 192015 

OFFICE OF CHEMICAL SAFETY 

ANO POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

TO: 

BEAD Chemical Profile (BCP) for Registration Review of Amicarbazone 

(1 14004) 

Sunil 

Biological 

Ratnayake

Analysis 

, Biologist 

Branch 

~ 

'· · ) ....._~ 

Rafael Prieto, Environmental Protection Specialist ;f}~ tC -P~ Science Information and Analysis Branch I' v f 

Andrew Lee, Economist a j ( h 

Economic Analysis Branch ? 

Biological and Economic Analysis Division (7503P) 

Arnet Jones, Chief 

Biological Analysis Branch 

Diann Sims, Chief 

Science Information and Analysis Branch ' 

Timothy Kiely, Chief fr. \l ~\~ Economic Analysis Branch ~'-' '-. 

Biological and Economic Analy i Division (75 B 

Maria R. Piansay, Chemical Review Manager 

Risk Management and Implementation Branch V 

Pesticide Re-evaluation Division (7508P) 

Peer Review Panel Date: April 15, 2015 
SUMMARY 

Amicarbazone was first registered in the United States in 2005 (USEPA, 2005). Amicarbazone is 

applied as pre and post-emergence treatments for the control of annual broad leaf and grass weed 

species. Initially, amicarbazone was registered for weed control in field corn and corn grown for 

silage. New uses were registered in 2012. 

INTRODUCTON 

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

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

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

use and usage data for amicarbazone to describe its role in pest management. Information 

provided in this BCP may be used by stakeholders (e.g., users and registrants), OPP risk 

assessors, OPP risk managers, and the general public during the Registration Review process of 

this pesticide. 

USE SITES 

Amicarbazone is registered for use in field corn and corn grown for silage. In addition, 

this herbicide is registered for use on turf on golf courses, turf in other areas, sod farms, 

residential and commercial turf sites, park and recreation areas, school grounds, and conifers in 

nurseries and field plantings (including Christmas trees). 

FORMULATIONS AND APPLICATION METHODS 

Amicarbazone is used as a dry flowable formulation for broad leaf and grass weed control. This 

herbicide is applied using ground application equipment. 

USAGE 

Usage data are not available for amicarbazone. 

HISTORY OF BEAD ASSESMENTS 

There is no history of BEAD assessments that are relevant to the current registration review. 

SECTION 18 EMERG ENCY REQUEST HISTORJES 

There are no section 18 assessments conducted by BEAD on this chemical. 

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BIOLOGICAL ASPECTS RELEVANT TO AMICARBAZONE 

Amicarbazone belongs to the phenylpyrazolin family of herbicides. It is a selective and systemic 

herbicide applied as pre and post emergence treatments for the control of broad leaf and grass 

weeds in crop production. Its efficacy as both a foliar and root-applied herbicide suggests that 

amicarbazone is absorbed and transported rapidly in the plants. The phenotypic responses of 

sensitive plants exposed to amicarbazone include chlorosis, stunted growth, tissue necrosis, and 

death. 

Amicarbazone is effective on controlling broadleaf weeds, including velvet leaf (Abutilon 

theophrasti), common lambsquarters (Chenopodium album), pigweed species (Amaranthus spp.), 

common cocklebur (Xanthium strumarium) and morning-glory species (fpomoea spp.) 

(Herbicide Handbook, 2014 ). Also, amicarbazone is especiall y effective for the control of annual 

bluegrass (Poa annua) a troublesome winter annual grass weed found in golf courses 

(Amicarbazone New Use Review, 2012). However, presence of an annual bluegrass biotype with 

resistance to triazine herbicide has shown cross resistance to amicarbazone herbicide (Perry et 

al., 2012). Turf grass species such as Kentucky bluegrass, fine fescue, tall fescue and perennial 

ryegrass species are tolerant to amicarbazone. 

According to the Weed Science Society of America (WSSA) mechanism of action classification, 

amicarbazone belongs to the Group 5 herbicides and it is a photosynthetic inhibitor (WSSA, 

Undated). As a result, amicarbazone is not effective on weed species that are resistant to PSII 

inhibitors such as triazines (atrazine, simazine, metribuzin) and weeds resistant to diuron. 

It has been reported that in the United States, 26 weed species have developed resistance to the 

Group 5 herbicides (Heap, Undated). 

DATA NEEDS 

Currently, no usage data is available on use of amicarbazone on agricultmal and non-agricultural 

use sites. On national level, number of pounds applied per year on individual agricultural and 

non-agricultural sites, typical application rates and timing would be useful in future assessments. 

REFERENCES. 

Amicarbazone. New Use Review. 2012. Onli ne Publication. Available at: 

https://v..ww.mda.state.mn.us/en/chemicals/pesticidcs/regs/-/media/Files/chemicals/rcvi 

cws/nur-amicarbazone.ashx. Accessed on March 30, 2015. 

Heap, I. (Undated).The International Survey of Herbicide Resistant Weeds. Online Publication. 

Available at: http://www.weedsciencc.org/summary/ResistbyActive.aspx. Accessed on 

January 28, 2015. 

Herbicide Handbook. 2014. I 01h edition. Weed Science Society of America. Pinoxaden. Pp 355-

356. 810 E. I01

h Street. Lawrence, KS 66044-8897. 

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Perry, G. H., McElroy, .J. S., Dane, F., van Santein, and R.H. Walker. 2012. Triazine-Resistant 

Annual Bluegrass (Poa annua) Populations with Ser26.i Mutation are Resistant to 

Amicarbazone. Weed Science: 60, No. 3, pp. 355-359. 

Weed Science Society of America (WSSA). Undated. Summary of Herbicide Mechanism of 

Action According to the Weed Science Society of America. Online Publication. 

Avail able at: http://wssa.net/wp-content/uploads/WSSA-Mechanism-of-Action.pdf. 

Accessed on March 31, 2015). 

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