UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASH I NGTON , D

. C

. 20460 

### MAY 192015

OFF I CE OF CHEMICAL SAFETY A N O POLLUT I O N PREVE N TIO N 

### MEMORANDUM SUBJECT:
FROM:

THRU:

TO: BEAD Chemical Profile (BCP) for Reg istration Review of Amicarbazone (1 14004) Sunil Ratnayake , Biologist

# ~ Biological Analysis Branch ' · · )

## ....._~ Rafael Prieto, Environmental Protect io n Specialist

# ;f}~**tC -P~**  Science In format ion an d Anal ysis Branch 

## I' v 

# f

Andrew Lee , Econom i st 

# a j ( 

# h Econom ic Analys is Branch 

# ? Biological and Economic Analysis Division (7503P) Arnet Jones , Chi ef Biological Ana lysis Branch Diann Sims, Chief Sc ience In formation and Anal ys is Branch 

### ' Timothy Kiely , C hi ef 

# fr. \l

# ~\~ Economic Analys is Branch

### ~'-'**'-.** Biologica l and Econo mi c Analy i Division (75 B Maria R. Piansay , Chemical Review Manager Risk Management and Imp lementation Branch V Pesticide Re-evaluation Di vis i on (7508P) 

### Peer Rev iew Panel Date : Apr il 15, 2015SUMMARY Amicarbazone was first registered in the United States in 2005 (USEPA , 2005). Amicarbazone is applied as pre and post-emergence treatments for the contro l of annual broad leaf and grass weed species. In itiall y, amicarbazone was reg istered for weed contro l in field corn and corn grown for silage. New uses were registered in 2012.

INTROD UCT ON The Biol ogical and Eco nomic Anal ysis Di v isio n (BEAD) Che mical Profile (BCP) prov id es an overview of the pest management roles and quantitative usage information for amicarbazone. The BCP includes summaries of previous B E AD products and available public and/or private use and usage data for amicarbazone to describe its role in pest manag ement. Information provided in this BCP may be used by stakeholde rs (e .g. , users and registrants) , OPP risk assessors , OPP risk mana gers , and th e general public during the R egistrat io n Rev iew process of this pesticide. USE S IT ES Amicarbazone is registered for use in field corn and corn grown for silage. In addition, this herbicide is reg i stered fo r use on turf on golf courses , turf in other areas , sod farms, residential and commercia l turf sites, park and recreation areas , schoo l grounds , and conifers in nurseries and field planti ngs (including Christmas trees). FORMULATIONS AN D A PPLIC AT IO N METHODS Amicarbazone i s used as a d ry flowable fo rmulation for broad leaf and grass weed control. Thi s herbicide is app lied using g round app li cation equ ipment. USAGE Usage data are not available fo r amicarbazone. HISTORY OF BEAD A SSESM ENTS There is no history of BEAD assessments that are re levant to the current registrat ion review. SECTION 18 EME RG ENCY REQUEST HISTORJES There are no section 18 assessme nts conducted by BEAD on th is c hem ical.

Pag e 2

### BIOLO G I CAL ASPECTS RELEVANT TO AM I CARBAZONE Amicarbazone belongs to the phenylpyrazol i n family of herbicides. It is a selective and systemic herbicide applied as pre and post emergence treatments for the control of broadleaf 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 sensiti ve plants exposed to amicarbazo ne in c lude chlorosis , stunted growth, ti ssue necrosis, and death. Amicarbazone is effective o n controlling broadleaf weeds , including velve t leaf 

### (Abutilon theophrasti) , common lambsquarters 

### (Chenopodium album) , pigweed species 

### (Amaranthus spp.) , common cocklebur 

### (Xanthium strumarium) and morn in g-glo ry species 

### (fpomoea spp.) (Herbicide Handbook , 2014 ). A lso, amicarbazone is espec ia ll y effective for the contro l of annual bluegrass 

### (Poa annua) a troublesome winter annual grass weed found in go l f 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 e t al., 2012). Turf grass species s uch as Kentucky bluegrass , fine fescue, tall fescue and perennial ryegrass species are to l erant to amicarbazone. According to the Weed Sc i ence Society of America (WSSA) mechanism of action classification, amicarbazone belongs to the Group 5 herbic ides and it is a photosynt heti c inhibito r (WSSA , Undated). As a result , amicarbazone is not effective on weed species that are resistant to PSII inhibitors such as triazines (atraz ine , simaz in e , metribuzin) and weeds resistant to diuron. 

### It has been repo rted that in the United States , 26 weed species have deve loped r es istance to the Group 

### 5 herbicides (Heap, Undated). 

### DAT A NEE D S Currently , no usage data is availab l e on us e of am icarbazone on agricultmal and non-agricultu ral use si tes. On national le vel , number of pounds applied per year on indi vidual agr icultura l and non-agricultural sites, typical application rates and timing would be useful in future assessments. 

### REFERENCES . Am icarbazone. New Use Review. 20 1 2. On li ne Publi cat ion. Availab l e at: http s: //v..ww . md a.s ta te . mn.u s/en/c he mi ca ls / pe s ti c id cs /regs/-/me di a/F il es/ c he mica ls/ rcv i cws/ nur- ami carb a zone.as h x . Accessed on March 30 , 2015

. Heap , I. (Undated).The International Survey of Herbicide Resistant Weeds. Onl in e Publication. Ava ilable at: http : //www . wee d sc i e ncc.o r g / s umm ar y / Res istbyAc ti ve.aspx . Accessed on January 28, 2015. Herbicide Handbook. 2014. I 0 1h edition. Weed Science Society of America. Pinoxaden

. Pp 355- 356. 810 E. I0 1 h Street. Lawrence , KS 66044-8897.
Page 3Perry , G. H. , McElroy, 

### .J. S., Dane , F., van Santein, and R.H. Walker. 2012. T ri azine- Resis ta nt Annual Blue g ra ss (Poa annua) Populations w ith Ser 26.i Mutation are Res is tant to Amicarbazone. Weed Science: 60 , No. 3 , pp. 355-359. Weed Scie nc e Society of America (WSSA). Undated. Summary of Herbicide Mechanism of Action According to the Weed Science Society of Ame rica. Online Publication. Ava il ab l e at: http: //w ss a . net / wp-content/uploads/ WSSA-Mechanism-of-Action

. pdf. Accessed on March 3 1 , 2015).

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