UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASH I NGTON , D .C. 20460 

### NOV 17 Z014

MEMORANDUM OFFICE OF CHEIJIICAL SAFETY AND POLLUTION PREVENTION



### SUBJECT: BEAD Chemical Profile for Regi strati o n Review: Dikegu l ac Sodiu m (109601) 

### FROM:

THRU: Car l Chen, Biologist B io l og ical Analysis Branch /J.f'\.**~~-·· '**  Cynthi a Doucoure, Environmental Protection Speciali s t L "**~** Sc ience Informat ion and

- Analysi s Branch

. .---? --;_

## ~ Derek Berwald , Economis t**~ ~**  · " Econom ic Analys i s Branch Biological and Economic Analysis Di v i s ion (7503P) Amet Jones , Chief Biological Analysis Branc Diann S ims, Chief Science Information and Analysis Branch T imothy Kie ly, Ch ief

# ~ (AA.. ., Economi c Analysis Branch Bio l ogical and Economic An y Divi s ion (7 ) TO: Matthew Manupella, Chemical Review Manager Ri s k Management and Implementation Branch (RMIB II ) Pesticide R e-eval uation Di vision (7508 P )
P rodu ct Review Panel date : Nov ember 5 , 2 0 14

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### SUMMARY Dikegulac sodium, a plant growth regulator, was fir s t registered in the U.S. in 1978. It is u sed on ornamental plants in greenhouses, nurseries , and on landscapes, as well as deciduous evergreen and conifer tree farm s. The Reregistration Eligibility Decision (RED) for Dikegulac Sodiu m was finalized in March 2007. Currently, there are thre e active Section 3 registrations for this chemical. Based on available data , dikegulac so dium appears to be used in very low amounts (400 lbs a.i.) in the nursery and flori c ulture sector in the U.S. (USDA NASS, 2006). California DPR, however, report s u se of dikegulac sodium in higher amounts (approximately 1,400 lbs a.i. o n average) in recent years (2008-2012), particular l y for landscape maintenance.


### INTRODUCTION The purpose of this document is to convey u sage information and a broad overview of the pest management role s of pesticides that are beginning to undergo regi st ration review
. The anticipated audience consists of the team of EPA staff currently evaluating the registration status of dikegulac sodium and eventually the general public. The document is based on information and data available to BEAD as of July 2014.


### COMMON FORMULATIONS AND APPLICATION METHODS Dikegulac sodium is formu lated as soluble and emul si fiable concentrates , as well as liquid ready

to-use.


### USE SITES Agricultural Use Sites Dikegulac sodium is l abe l ed for use on farms for deciduous evergreen and co nifer trees , including Chri s tmas trees. Non-Agricultural Use Sites Dikegulac sodium is labeled for use in greenhouses, nurseries, and on land scape trees, hedges, s hrubs, groundcovers, flowering plants and other ornamentals. Landscape areas include parks, sc hool campuses, city streets, and similar recreational, institutional , or indu s trial areas.

Page 2 of 4DIKEGULAC SODIUM USAGE IN THE U.S. BEAD revi e wed available d ata sources and found that only U SDA NASS r eported national use of dikegulac s odium in the nursery and floriculture sector in 2006, where approximately 400 lb s a.i. were appli ed at a n average a.i. rate of 2.057 lb s a.i. per acre. Cal ifornia DPR, however , reported use of dikegulac so dium in higher amounts in rece nt years ( 2008 -2012) , particu l arly for landscape maintenance, where an average of 1,400 lbs a.i. w ere app l ied annually 

### as shown 

### m Table 1.
T bl 1 D"k

a e 1 egu ac o mm sem a 1 orn1a 

## s d" 

## u . c rf Sector Pounds A.I. Ap11lied Yearly 

### 2008 2009 2010 2011 2012 Avg. Rights

- of

- way 10 24 2 8 3 9 Land sc ape 967 2.435 2 ,728 1 ,3 49 1,982 1, 4 00 Maintenance Source: CA DPR , 2007-20 12

BIOLOGICAL ASPECTS RELEVANT TO DIKEGULAC SODIUM Dikegulac so dium is a plant growth regu lator registered for non -agricultural use s. It is a growth re tardant labeled for u se on many plants such as hedges, s hrub s, tre e s and gro undcovers. It is a DNA s ynthe s i s inhibitor labeled for greenhouses and nurserie s and has high activity (USD A, 2004). It can also be used to prevent flowering and unde s ired fruit s et.
ROLE OF DIKEGULAC SODIUM IN PEST MANAGEMENT Landscape maintenance in Cali fornia is reported a s the main use of dikegulac sodium in term of pound s a.i. app lied
. Other uses in California include structura l contro l , nursery crops, and rights-of

- way (CDPR , 2012). In North Carolina, dikegulac s odium has been recommen ded for us e on land sc ape in stallation and maintenan ce including ornamental s as a c hemical pincher to increase plant branching for bushy plants (USDA , 2004; USDA, 2005). It can be used to c ontrol growth of shrub s and to prevent fruit-set in land scapes (USDA , 2005).
INFORMATION THAT MAY BE USEFUL FOR BEAD ' S FUTURE WORK ON DIKEGULAC SODIUM The Agency currently does not have certain important information o n dikegu lac s odium. Obtaining the following information may improve future a ssess ments con du cted by the Age ncy related to the u se and importance of dikegulac sodium. I. 

## ',
. ( 

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I Page',3 of 4• Current usage information (pounds a.i. applied, average a.i. rate of application and number of application) on all sites. • Geographic distribution of dikegulac sodium use in the U.S.



### REFERENCES CDPR. 2012. Summary of Pesticide Use Report Data. California Department of Pesticide Regulation. P.O
. Box 4015. Sacramento, CA 95812-4015 USDA NASS, 2006 USDA. 2004. Crop Profile for Ornamental Plants in North Carolina. Available at: http://www.ipmcenters.org/cropprofiles/docs/NCornamentals.pdf USDA. 2005. Crop Profile for Landscape Installation and Maintenance in North Carolina. Available at: http://www. ipmcenters.org/cropprofiles/docs/NC!andscape.pdf

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