UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

DEC 20 2010

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

MEMORANDUM

SUBJECT: BEAD Chemical Profile for Registration Review: Cyclanilide

2- 14 1\1 Elizabeth Hill, Economist

Economic Analysis Branch

Biological and Economic Analysis Division

Arnet Jones, Chief j /7

Biological Analysis an h/ / .

Diann Sims, Chief £l '-l- Science Information and Analysis Branch

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Monisha Kaul, Biologist (Yl01WW 1/ /7" . P

Biological Analysis Branch <,,

Jihad Alsadek, Economist ,T < -1.

Science Information and Analysis Branch

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TO: Yan Donovan, Chemical Review Manager

Pesticide Reevaluation Division (750 8P)

Peer Review Panel date: August 25, 2010

INTRODUCTION AND SUMMARY OF CYCLANILIDE USE SITES

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 cylanilide, and eventually the general public. This document builds upon the data already

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provided in the "Usage and Label Use Data Packages" that are also provided to Registration

Review teams by BEAD.

Cyclanilide is a plant growth regulator registered for use in cotton. Cyclanilide products for use

on cotton contain cyclanilide mixed with one other active ingredient, either ethophon or

mepiquat chloride. Cyclanilide products have several use restrictions or precautions including

plantback restrictions and climatic and growth stage application requirements. Cyclanilide

appears to be a commonly used plant growth regulator in cotton production.

(GtK Kynetec, 2004 -2008).

Cyclanilide is also registered for use on non-agricultural, ornamental use sites including shade

trees, herbaceous plants, non-flowering plants, and woody shrubs. Cyclanilide can be used on

nursery stock of apple, cherry, pear, and plum. Two products are registered for these uses.

There are also established tolerances for residues of cyclanilide in cottonseed, cotton gin byprodu cts, milk fat, meat, meat by-products, and cattle, goats, horses, hogs, and sheep kidneys.

This document will discuss the uses of cyclanilide in plants focusing on the use in cotton

production.

COMMON FORM ULATIONS AND APPLICAnON METHODS

This chemical is formulated as liquid and emulsifiable liquid. It may be applied as a spray, foliar

treatment or broadcast.

USAGE

Agricultural

Based on private market pesticide usage data from 1998-2008, the average agricultural usage

(excluding seed treatments) is approximately 156,000 pounds active ingredient for almost 1.5

million acres (GfK Kynetec, 1998-2008). Cyclanilide usage is mainly on cotton and it fluctuates

from year to year.

From 1998-2008 , the largest market in terms of total pounds of active ingredient applied is

cotton (100%) (GtK Kynetec, 1998-2008).

The states with the most cotton usage in terms of pound s AI applied are:

Georgia (18%), North Carolina (I5%), Arizo na (13%), and Texas, Tennessee, Mississippi (10%

each). The states with the most total area treated (TAT) are : Texas and Georgia (17% each),

North Carolina (13%), Mississippi (11%), and Arizona (10%) (GtK Kynetec, 1998-2008).

Non-Agricultural

Cyclanilide's usage data on ornamental plants are not ava ilable from our current data sources.

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USE TRENDS

The following graph provides usage trends, in terms of pounds applied, for cyc lanilide's largest

agricultural markets. The data provided in this section are provided for preliminary scoping

purpo ses.

Cotlon

250.000 ,-- - ------- - --- --- -

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1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Year

BIOLOGICAL ASPECTS RELEVANT TO CYCLAN ILIDE

Cyclanilide is used as a plant growth regulator and defoliant in cotton production. Defoliation

just before harvest prevents leaf pigments from staining and reducing the quality of cotton fiber

(Pedersen, et al., 2006). Defo liants also aid in increasing yield in a single harve st (Pedersen, et

aI., 2006).

Cyclanilide products for use on cotton are combined with one other acti ve ingredient, either

ethephon or mepiquat chloride. The product Finish 6 Pro Harvest Aid®includes the active

ingredient ethephon. It is used to accelerate opening of mature cotton bolls, promote defoliation

of both mature and j uvenile foliage, and reduce terminal height (CDMS, 20 10). Climatic

precautions including rainfall and temperature are listed on the label. Plantback restrictions in

the US, other than California and Arizona, on the product label state that small grains or leafy

vegetables can beplanted after 30 days of the last applicat ion and any other food crop can be

planted afte r four months of last application. In California and Arizona, any food crop may be

planted after 30 days.

Another cyclanilide prod uct. Stance Plant Growth Regulatort'", is a low dose plant growth

regulator for early and mid season cotton crop management (CDMS, 20 10). According to the

product label, Stance Plant Growth Regulatortw contro ls growth, promotes early maturity,

increases fruit retention, reduces boll rot and increases in crop manageability. This product

includes two active ingredients: mepiquat chloride plus cyclanilide. It may befirst applied when

at least 50 percent of co tton plants have at least one percent match head squares (first flora l

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buds). New small grain and leafy vegetable crops can be planted after 75 days oflast

application. Any other crop can be planted after four months of last application.

The primary use of cycianilide is for boll opening and defoliation in cotton (GfK Kynetec, 2004 -

2008). According to chemical usage data, there are many alternatives used for boll opening such

sulfcarbamide, tribufos, and thidiazuron among others. However, the data indicate that ethephon

and cyclanilide are applied to the most cotton acreage for boll opening (GfK Kynetec, 2004 -

2008). In addition, according to chemical usage data reported, there are many alternatives used

for defoliation such as tribufos, thidiazuron, and diuron among others. Tribufos and thidiazuron

are used for defoliation on the most cotton acreage followed by ethephon, diuron, and cyclanilide

(GIK Kynetec, 2004 -2008).

Cyclanilide is also used in ornamental and nursery production. In nursery production,

cyclanilide has been found to induce lateral branch growth in trees as an alternative to

mechanical pruning to produce compact, full trees (Holland. et al., 2007; Banko and Stefani,

2007; Elfving and Visser, 2006). Two products are currently registered for such uses:

Cyclanilide 18% and Tiberon 2.8% SCI}.

HISTORY OF BEAD ASSESSMENTS FOR CYCLANILIDE

According to BEAD's Official Records Database, and RD's Section 18 database, there have

been no emergency exemption requests for cyclanilide. There are also no formal benefits

assessment memoranda from BEAD for this growth regulator.

DATA NEEDS RELEVANT TO BEAD'S FUTURE WORK ON CYCLANILIDE

Obtaining additional information on the following items would improve BEAD's assessment of

the importance of cyclanilide as a plant growth regulator. This assessment is likely to be required

as part ofthe registration review ofthis pesticide.

1. Information on grower's selection criteria for growth regulator at each crop stage where

cyclanilide may be used.

2. Cyclanilide usage data for ornamental sites and information on effective alternatives.

3. For agricultural uses, worker activities that occur in treated fields at the typical time of

cyclanilide applications.

4. Comparative costs of cyclanilide versus other growth regulators in identified use sites.

REFERENCES

Banko, TJ . and Stefani, M.A., 2007. Cyclanilide Promotes Lateral Branching in Nursery

Production of Woody Landscape Species. Journal ofEnvironmental Horticulture 25(4):215-

220. Accessed online:

hnp :/I""w.hriresearch.org/doc s/publications/JEHIJEH 2007/JEH 2007 25 4/JEH%2025-4-

SNI.pdf, August 16, 2010.

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CDM S, 20 10.

ELFVIKO D.C., VISSER D.S. 2006. The use of bioregulators in the production of

deciduous fruit trees. Acta Hort. (ISHS) 727:57-66 . Online:

http://v.'WW.actahort.orglmembers/showpdflbooknramr=727 4. Accessed: August 16,2010.

OtK Kynetec, 1998-2008.

OtK Kynetec, 2004 -2008.

Holland, A.S ., OJ. Keever, J.R. Kessler, Jr., and F. Dane , 2007 . Multiple Cyclanilide

Applications Promote BranchingofWoody Ornamentals. Journal of Environmental Horticulture

25(4):191-1 96. Accessed online:

hrtp://"",w.hriresearch.orgldoc s/publicalions/JEH/JEH 2007/JEH 2007 25 4/JEH%2025-4-

SNI.pdf, Augu st 16, 20 10.

Pede rsen, M.K, J.D. Burton, and H.D. Coble, 2006. Effect ofCycianilide, Ethephon, Auxin

Transport Inhibitors, and Temperature on Whole Plant Defoliation. Crop Science 46:1666-1672.

Accessed online: https://www.crops.orglpublications/cs/articles/46/4/1666, August 17, 20 10.

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