US EPA FOCUS MEETING 

CYHALOFOP BUTYL

Dow AgroSciencesJuly 11 2014

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July 11, 2014
Agenda

Regulatory Overview & Product ProfileCharge QuestionsQ & A
Regulatory Overview

• Postemergence herbicide for selective control of grass wee

> Dry drill-seeded> Water-seeded

• Excellent selectivity on all rice varieties and rice hybrids• Aryloxyphenoxy propionate chemical family propionate chemical family• Inhibits the Acetyl CoA Carboxylase (ACCase) enzyme
Regulatory Overview

• 1996 – First registrations in Philippines and Japan• 2000 – Cyhalofop-butyl was granted Reduced Risk Pesticid

designation in rice.

• 2007 – EPA classified cyhalofop-butyl as “Not Likely to be 

Carcinogenic to Humans.”

• 2009 – EPA removed temporary registration status and oth

restrictions to restrictions to cyhalofop cyhalofop-butyl and Clincher and Clincher formulations formulations.

Products currently are registered in all key major rice growing 
EPA Charge Questions & DAS Responses

Discuss locations of use across the country. These are of pa

imp gp ortance to focus our endan

gered species assessment.

Arkansas, California, Louisiana, Mississippi, Missouri, and Te
EPA Charge Questions & DAS Responses

Discuss the spectrum of plants that are affected by the mecha

action for this chemical.

Only grasses are affected by the mechanism of action of cyha

Cyhalofop-butyl has no activity on any broadleaf or sedge w
EPA Charge Questions & DAS Responses

Discuss Dow AgroSciences plan for wild rice.Dow AgroSciences does not intend to label this use.
EPA Charge Questions & DAS Responses

Can Dow AgroSciences provide a bibliography of studies for a

develop p ed for Europe or elsewhere

?

Yes. This list will be provided via email.
EPA Charge Questions & DAS Responses

Can Dow clarify all labels with the term “post-flood.” For exam

water-seeded rice, is the “postfloo

d” app p lication the 

period 

flood for seeding, or application period after permanent flo

Post-flood refers to any time after seeding that the fields are f

water and that grass weeds would be present in the rice. Tflood can be both of the examples provided.
EPA Charge Questions & DAS Responses

Clincher DR is referenced as a supplemental application prod

Clincher GR 

( ) southern states). Is Clincher DR a re

g 

istered 

Clincher DR is an alternate brand name for Clincher GR as re

the EPA Notice of Registration and stamped approved labeSeptember 30, 2010.
EPA Charge Questions & DAS Responses

How is Clincher used in the ratoon rice production process?Very little Clincher is used in ratoon rice. An estimated 50 ga

season is applied which – at the 15 oz/acre rate – would tre

than 500 acres. It is typically used as a spot spray, not brocontrol patches of grass weeds.
EPA Charge Questions & DAS Responses

How are buffer zones established? Buffer distances for the s

commodityy g p , g 

 vary amon

g labels. In 

particular, for endan

gere

the RebelEX has a smaller distance for the Southern StateCalifornia.

Buffer zones are established with modeling and actual drift stuAn additional safety margin was applied for the products used 

because of the local conditions. 
EPA Charge Questions & DAS Responses

Why can the granule formulations be only applied to “water-se

rice? It seems that the 

g pp y ranule could be applied to “dry-see

since the granule is applied to flooded waters.

The Clincher granule can only be used to control grasses that 

completely (>80%) submerged at the 1-3 leaf vegetative stage. Water-seeded rice maintains a flood, and grass wee

controlled while small (1-3 leaf stage) and submerged. Howthe time dry-seeded rice is flooded, grass foliage needed fouptake is neither submerged nor small, and foliage is not aunderwater for herbicide uptake. 
ADDITIONAL QUESTIONS? 

Thank you!

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