STATE OF WASHINGTON 

DEPARTMENT OF AGRICULTURE 

P.O. Box 42560 • Olympia, Washington 98504-2560 • (360) 902-1800 

March 16, 2016 

Tawanda Maignan, Team Leader (Team 9) 

Risk Integration, Minor Use, and Emergency Response Branch 

U.S. EPA Office of Pesticide Programs (7SOSP) 

Room S4900, One Potomac Yard 

2777 Crystal Drive 

Arlington, VA 22202 

RE: Emergency use of pyridate (Tough SEC Herbicide) in mint 

Section 18 of the amended FIFRA provides the Administrator may exempt a state or federal agency from 

provisions of FIFRA if a determination is made that emergency conditions exist which require such 

exemption. The Washington State Department of Agriculture is applying for a specific exemption for the 

use of pyridate (Tough SEC) to control kochia, red root pigweed, and other problematic broad leaf weeds 

in mint. This is our third request for this emergency use, but our first such request since 2000. Please 

refer to similar section 18 requests submitted by the Oregon Department of Agriculture and Idaho 

Department of Agriculture for additional information. 

Information required in 40 CFR 166.20 (a) is presented below. 

A. Summary of General Information 

1. Type of Exemption: Specific 

2. Contact Persons: 

Steve Salisbury (Technical) Dr. Rick. Boydston (Scientific) 

Mint Industry Research Council USDA-ARS Irrigated Ag. Research & Ext. Center 

PO Box 4059 24106 N. Bunn Rd. 

Salem, OR 97302-1059 Prosser, WA 99350-8694 

Phone: 503-551-3747 Phone: 509-786-9267 

Email: eve(a>~a ci ficag esou ce .com Email: rick.bo~dston@ars usda.gov 

ShaneJohnson(Economic~ Liesbeth Bosman (Registrant) 

Washington M int Commission Belchim Crop Protection, Inc. 

100 North Fruitland St., Suite B Technologielaan 7 

Kennewick, WA 99336 1840 Londerzeel, BELGIUM 

Phone: 509-585-5460; Email: Phone: +32 (0) 473 86 52 33 

ShaneJ@agmgt.com Email: Liesbeth.Bosman(a)Belchim.com 

1 
Mr. Richard Carver, US Registration Agent 

Critical Path Services (a Knoell company) 

3070 McCann Farm Drive, Suite 112 

Garnet Valley, PA 19060 

Tel. 610.SS8.300; Fax 610.SS8.602S 

(see Attachment 8) 

3. Description of Pesticide: 

Active Ingredient: Pyridate 

Trade Name: Tough Herbicide SEC (not currently registered in U.S.) 

Formulation: Emulsifiable concentrate SS.8% (S.O lb. ai. per gal.) active ingredient. 

Registrant/Manufacturer: Belchim Crop Protection 

U.S. Distributor: Engage Agro USA Corp. 

4. Description of Proposed Use: 

a. Sites to be Treated: Peppermint and speafmint grown in following counties of Eastern Washington: 

Adams, Benton, Franklin, Grant, Kittitas, Lincoln, and Yakima. 

b. Method of Application: Tough SEC may be applied by ground equipment only. 

c. Rate of Application: A maximum application rate of 24 fl. oz. (0.937S lb. active ingredient) may be 

used per acre. 

d. Maximum Number of Applications: One application. 

e. Total Acreage to be Treated: Approximately 1S,SOO acres (SO% of total Washington acreage may be 

affected). 

f. Total pesticide to be used: 2,906 gallons (14,S311bs. active ingredient) 

g. Use Period: April1 through December 31, 2016. 

h. Harvest Dates: The majority of peppermint acreage is harvested once in August. However, some 

peppermint growers are double cutting their crop. Double-cut mint is harvested twice during the 

growing year, once in June and again in late August or early September. Spearmint is harvested twice 

during the growing season, once in the middle of June and again in the middle of August. 

i. Other Restrictions, User Precautions, and Requirements 

• The product container label for Tough'M S EC Herbicide (Attachment 1) and the Washington 

Section 18 use directions (Attachment 2) for mint must be in possession of the user at the time 

of pesticide applications. Follow all precautionary/hazard and worker protection requirements 

on the product labeling. 

• Do not enter or allow worker entry into treated areas during the restricted-entry interval 

(REI) of 24 hours. 

• Do not use treated fields or forage for livestock feed or grazing. 

• Do not apply Tough SEC Herbicide through any type of irrigation system or by air. 

• Do not apply Tough SEC to mint within 49 days before harvest. 

• To protect endangered plant species, one of the following options must be used: 

(1) Apply only when there is a sustained wind away from wetland/transitional zone native 

2 
plant communities; 

(2) Leave a 25-foot buffer between treatment area and wetland/transitional zone native 

plant communities; or 

(3) Use low pressure nozzles according to manufacturer's specifications that produce only 

coarse or very coarse droplets. 

• To protect endangered freshwater invertebrate species, do not apply ToughTM within 100 yards 

of any freshwater spring. 

• Any adverse effects that may result from the use of ToughTM under this emergency exemption 

must be immediately reported to the Washington State Department of Agriculture. 

• Any unused, unregistered product must either be returned to the manufacturer or distributor 

(unopened containers), or be disposed of in accordance with the Resource Conservation and 

Recovery Act (RCRA) regulations following the expiration of the emergency exemption. 

5. Alternative Methods of Control: 

a. Registered Post-Emergent Herbicide Alternatives 

1. Bentazon (Basagran) provides inconsistent (partial) post-emergence control of kochia and does 

not control pigweed. Weeds emerging after application are not controlled. 

2. Terbacil (Sinbar) does not control kochia and pigweed, which has developed resistant biotypes 

due to years of continuous use. Terbacil does not provide effective control of weeds larger than 

seedlings. Terbacil is not an option when rotating from mint into other crops t he following year 

due to soil persistence and crop rotational restrictions. Terbacil should not be applied to mint on 

sandy, loamy sands, or soils with less than 1% organic matter to avoid injury. 

3. Bromoxynil (Maestro) is phytotoxic to actively growing mint and should not be applied above 70 

degrees F to actively growing mint. This herbicide gives partial control of kochia and pigweed 

seedlings only. 

4. Clethodim (Select Max), sethoxydim (Poast Plus), and quizalifop (Assure II) provides grass weed 

control only. 

5. Clopyralid (Stinger) may be used for spot treatment, post emergence control of broadleaf 

weeds, such as Canada thistle and dandelion. It does not provide effective control of kochia or 

pigweed. Use of this herbicide can damage mint. 

6. MCPB (Thistrol)- Can only be applied early post-emergent to weeds and to dormant or small or 

newly emerged mint. Use of this herbicide does not provide complete control of Canada thistle 

and field bindweed and can injury mint. 

b. Other alternatives 

Mechanical weed control methods, such as tillage, are not feasible or practiced in actively growing 

mint. Tillage damages the crop and can spread diseases (Verticillium wilt) and rhizomes and stolons 

of perennial weeds. Hand roguing is cost prohibitive and does not provide season long control of 

weeds. In addition, the labor needed for hand weeding is not generally available. No effective 

biological control methods have been developed. 

c. Ongoing Research for Chemical Alternatives: Numerous pre-emergent and post-emergent 

herbicides have been tested and evaluated over the past decade, with little or no success. The mint 

industry has been diligently investing research funds to discover effective post-emergent broadleaf 

weed herbicides, which are safe to mint. Dr. Boydston explained that sulfentrazone (Spartan) 

applied at low rates after the first mint harvest has provided good control of pigweed with little 

injury to mint and an IR-4 project was initiated to develop a label for this use, but after numerous 

years sulfentrazone is still not labeled in mint for this use (Attachment 3). Bentazon, terbacil, 

bromoxynil, bicyclopyrone, mesotrione, tembotrione, topramezone, fluroxypyr, MCPB, and 

3 
carfentrazone have been tested alone and in various tank mixes applied postemergence to mint. 

They have either been too injurious to the mint or do not adequately control the pigweed. Pyridate 

has proven to be effective on broadleaf weeds as well as possesses acceptable post-emergence crop 

safety needed for mint production. Populations of problem weeds have reached economically 

devastating levels and is impacting the pr.oducers' ability to compete in the market. Additionally, the 

recent increased demand for double-cut mint has forced production into and created an un-routine 

situation for mint producers who have no effective and viable postemergence broad leaf weed 

control options. 

6. Efficacy of the Proposed Use: According to Dr. Rick Boydston, Weed Scientist, USDA pyridate has 

been the most effective herbicide for postemergence control of broadleaf weeds that he has tested 

while also exhibiting excellent crop safety {Attachment 3). 

7. Residue Information: The established tolerances for residues of pyridate and its metabolites in/on 

peppermint and spearmint is 0.2 ppm 

8. Risk Information: WSDA is referencing the information submitted by the Oregon Dept. of 

Agriculture on March 11, 2016. Endangered or Threatened Species in Washington are listed in 

Attachment 4. 

9. Coordination with Other Agencies 

The Washington Fish and Wildlife Office of the U.S. Fish and Wildlife Service will receive a copy of 

this request. Any comments received will be forwarded to the U.S. EPA. 

10. Notification of Registrant 

Belchim Crop Protection, which is the registrant, supports this emergency request (AttachmentS). In 

addition, Engage Agro USA, which is the U.S. distributor, also supports this request (Attachment 6). 

11. Enforcement Program 

The Washington State Department of Agriculture (WSDA) has adequate authority for enforcing 

provisions of Section 18 emergency exemptions. 

12. Repeat Uses 

EPA granted Section 18 emergency exemptions for use of pyridate (Tough SEC, Novartis Crop 

Protection, EPA Reg. No. 100-880) on mint in Washington in 1999 and 2000. This is the third time 

that WSDA has requested use of pyridate on mint under FIFRA Section 18. 

Tough SEC (EPA Reg. No. SS947-168, Sandoz Agro) was first registered for use on corn and peanuts 

in 1997. The registration was transferred to the successor companies Novartis and then Syngenta 

Crop Protection under EPA Reg. No. 100-880. On May 24, 1999, EPA granted a Section 18 emergency 

exemption to Washington for the use of Novartis' Tough SEC Herbicide for control of red root 

pigweed and kochia in mint. EPA re-authorized the emergency exemption to Washington in 2000 for 

use of pyridate in mint to control weeds that had become resistant to registered alternative 

herbicides. The SLN WA-010007 for use of Tough SEC on mint was first registered in 2001. 

Therefore, it was not necessary to submit an emergency request since 2000. 

Syngenta Crop Protection decided to not support the re-registration of pyridate and voluntarily 

cancelled the registration of Tough SEC in the U.S. in 2004. WSDA cancelled WA-010007 for use of 

Tough SEC (EPA Reg. No. 100-880) in mint on January 1, 2008. 

4 
13. Progress Towards Registration 

Syngenta recently transferred the U.S. marketing rights for pyridate to the Belchim Crop Protection 

company of Belgium. Belchim has had initial meetings with EPA to discuss reestablishing U.S. 

registration of pyridate on certain crops, including mint. Attached is a list of major studies scheduled 

in support of updating the pyridate dossier for the re-submission at EPA, which is currently foreseen 

for September 2016 (Attachment 7). 

B. Summary of Economic loss Information Required 

1. Pest(s) to be Controlled 

Kochia (Kochia scoparia} and red root pigweed (Amaronthus retroflexus} 

2. Discussion of the Economic loss 

Kochia and red root pigweed have become resistant to registered post-emergent herbicides. A 

non-routine situation in Washington is present because mint growers "lost" the use of pyridate 

when Syngenta voluntarily cancelled the registration in the United States. There are no other 

registered herbicides, which can provide effective post-emergent control of kochia, pigweed, and 

other broadleaf weeds in double-cut mint. Broadleaf weeds will lower mint yield and will reduce the 

quality of mint oil if present in the mint crop at harvest. 

Pre-emergent herbicides, which may be applied in February to early March on dormant mint, 

generally loses effectiveness after 4-6 weeks. New weed flushes can occur after the removal of the 

mint canopy following the first cutting in mid to late June. There are no effective post-emergent 

herbicides that are labeled in mint for control of pigweed and broadleaf weeds during the second 

half of the growing season. A non-routine situation is present when growers are not able to produce 

quality double-cut mint due to broad leaf weed problems. 

3. Discussion of Economic l oss 

Economic thresholds for pigweed and kochia are very low. Weeds resistant to herbicides which 

mature and form seeds, soon establish large populations of the resistant biotype, if not controlled. 

Redroot pigweed present in mint at 1.6 weeds/yd2 renders mint oil unmarketable, due to off-flavors 

imparted during the distillation process. Studies performed by Oregon State University weed 

scientists have demonstrated that a redroot pigweed infestation of 10 plants/ft2 can reduce 

peppermint oil yield by 46%. Kochia can grow to heights of six feet and several feet in diameter· if it · 

is not controlled. An infestation of 2.3 kochia plants/ft2 can reduce mint oil yields by over 30% and 

reduce oil quality. Kochia and red root pigweed are often found in complexes of other weeds, which 

further reduces the yield and quality of mint oil. 

Dr. Boyston, USDA Weed Scientist, explained that uncontrolled weeds lower mint oil yield and 

quality (off flavors and color). Therefore, good weed control is critical for maintaining high quality oil 

and profitability (Attachment 3). Numerous studies and on-farm use have demonstrated that 

pyridate controls kochia, pigweed, common lambsquarters, nightshade species and other broadleaf 

weed escapes with virtually no injury to the mint crop, allowing greater oil yields and higher quality 

oil that is free of weed contamination. There continues to be a critical need for pyridate in mint 

production. 

Tier 2 Analysis 

The Tier 2 Significant Economic loss (SEll analysis below shows a 20.4% loss of gross revenue based 

on a combination of reduced oil yield and quality associated with the devaluation of tainted oil 

resulting from weed contaminants. 

5 
Assumptions 

• The average yield of 1211bs oil/acre is based on the five-year average (2011-2015) from mint 

industry oil growers and buyers oil/acre. 

• The average loss in oil yield is based on field research trials conducted with pyridate compared 

to bentazon and/or buctril in 1993 and 2000 in spearmint and peppermint. 

• It is estimated that control of the problem weeds will reduce the amount of tainted oil produced 

(i.e. increase production of untainted oil) by 20% overall. 

• The devaluation oftainted oil ranges from a small percentage deduction to complete 

rejection/loss. Based on industry knowledge, an average devaluation of 35% was used for this 

analysis. 

This represents an estimated loss of more than $18 million to the mint producers in Washington. 

Tier 2 Washington Economic Analysis of Yield and Quality Loss 

Routine Non-Routine 

Emergency 

Oil Yield (lbs I acre) 141 121 

Gross Revenue (GR) I Acre 

GR Untainted Oil ($21 lb) I Acre $2,665 a/ $1,779 C/ -- - - -- -

GR Tainted Oil ($13.65 lb) I Acre $192 b/ $496d/ 

Total Gross Revenue ($/Acre) $2,857 2,275 

To!al $ Loss of GR $583 

loss as a % of Gross Revenue 

at GR Routine/ Untamted Oil-- 1411bs/ A X 90% of yield X $21/lb (untamted Oil) 

b/ GR Routine/ Tainted Oil= 14llbs/A X 10% of yield X $13.65/lb (tainted oil) 

'

1 GR Non-Routine/ Untainted Oil= 12llbs/A X 70% of yield X $21/lb 

d/ GR Non-Routine/ Tainted Oil= 12llbs/A X 30% of yield X $13.65/lb 

%Change 

14.2% 

20.4% 

If you have any questions, please contact this office at (360) 902-2030 or Steve L. Foss at (360) 

902-2049 or e-mail sfoss@agr.wa.gov. 

Sincerely, 

~~\::JC_N __ _ 

Robin Schoen-Nessa, Program Manager, Registration Services 

SLF:cs 

cc: Steve Salisbury, Mint Industry Research Council 

Shane Johnson, Washington Mint Commission 

Liesbeth Bosman, Belchim Crop Protection 

Eric Maurer, Engage Agro USA 

6