Montana Section 18 Exemption Request For 

Tough® Herbicide (pyridate) in Chickpea 

Section 18 of 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 that requires 

such an exemption. The Montana Department of Agriculture is requesting a specific exemption 

for the use of Tough SEC (pyridate) to control kochia, including glyphosate-resistant kochia in 

chickpea. 

Information required in 40 CFR 166.20(a): 

1. Type of Exemption: Specific 

2. Contact Person: 

Linda Johns 

Pesticide Licensing, Registration, and Training Program Manager 

MT Department of Agriculture 

302 N. Roberts St. 

Helena, MT 59601 

Phone: 406-444-3676 

E-mail: ljohns@mt.gov 

Qualified Expert: 

Edward S. Davis 

Agriculture Specialist, Cropland Research 

Montana State University 

Land Resources and Environmental Science 

RmMarshLab 

Bozeman, MT 59717 

Phone: 406-994-7987 

Email: edavis@montana.edu 

Brian M. Jenks, Ph.D. 

Weed Scientist 

North Dakota State University 

5400 Highway 83 South 

Minot, ND 58701 

Phone: 701-857-7677 

E-mail: brian.jenks@ndsu.edu 

Davy Van Berlamont 

(Registrant) Belchim Crop 

Potection, Inc. 

Technologielaan 7 

1840 Londerzeel 

Belgium 

Phone: +32 (0) 473 86 52 33 

Email: Davy. V anBerlamont@belchim.com 
3. Description of the Pesticide: 

Common Name: Pyridate 

Trade Name: Tough SEC, not currently registered in U.S. 

Formulation: Emulsifiable concentrate formulated at 55.8% (5.0 lb. ai. per 

gal.) and 44.2% inert ingredients. 

Manufacturer: Belchim Crop Protection a Belgium based company (EPA Company 

No. 91746). The U.S. distributor is Engage Agro USA Corp. 

Material Safety Data Sheet (MSDS) and labels are attached. 

4. Description of Proposed Use: 

a) Site to be Treated: 

Pyridate could be used statewide in Montana on chickpea where kochia or 

glyphosate-resistant kochia are present at densities that would cause economic loss if 

not controlled. 

b) Method of Application: 

Ground application in 20-30 gallons per acre broadcast with sprayers equipped 

with suitable nozzles and screens no fmer than 50 mesh. The herbicide will be 

applied by ground-driven spray equipment by licensed applicators according to 

the proposed Section 3 product label and Section 18 label. Tough®SEC may not 

be applied by aerial methods or through any type of irrigation system and 

prohibitions on these types of applications are included on the Section 18 label. 

c) Rate of Application: 0.9375 pounds a.i per acre. This equates to 1.5 pt or 24 fl oz 

of product per acre. 

d) Maximum Number of Applications: 

Two applications of Tough per growing season may be made if necessary with 

spray interval of 20 days (maximum of 3 pt or 48 fl oz per season). No 

applications will be made within 60 days of harvest. 

e) Total Number of Acres to be Treated: 

Projected 61 ,200 (90% of estimated 68,000 total acres planted) 

f) Total Amount of Pesticide to be Used: 

57,375 pounds active ingredient for one application, 114,750 pounds 

active ingredient would be the maximum with two applications. 
g) Use Period: 

April 1, 2016 through December 31 , 2016 

Chickpea is typically harvested in early to late September. A fall application after 

harvest may be necessary if conditions promoting weed growth occur. No 

applications will be made within 60 days of harvest. 

h) Additional Restrictions: 

Additional measures should be taken to minimize drift and exposure on threatened 

and endangered plant species in Montana. 

Federal and supplemental labels address reentry and worker protection, 

environmental hazards and restrictions (see attached label). 

(1) To avoid excess residues, do not apply within 60 days of harvest. 

(2) DO NOT make more than 2 applications 

(3) DO NOT apply by air. 

(4) DO NOT apply this product through any type of irrigation system. 

(5) DO NOT apply this product when wind conditions will allow drift to adjacent 

susceptible vegetation. 

(6) DO NOT allow livestock to graze on treated fields. 

(7) DO NOT feed forage, hay or silage from treated fields to livestock. 

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

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

native 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 Tough®5EC 

within 100 yards of any freshwater spring. 

Any adverse effects resulting from the use of Tough®5EC under this emergency 

exemption must be immediately reported to Montana Department of Agriculture. 

Unused product: Any unused, unregistered product must either be returned to the 

manufacturer or distributor in unopened containers, or disposed of in accordance 

with the Resource Conservatism and Recovery Act (RCRA) regulations following 

the expiration of the emergency exemption. 
Chemigation: For use under this Supplemental label, do not apply this product 

through any type of irrigation system. 

Users are required to comply with all directions, precautions, and directions the 

exemption use directions and approved labeling for Tough SEC. 

5. Alternative Methods of Control: 

a) Registered Alternative Pesticides 

Sulfentrazone, pendimethalin, ethalfluralin, trifluralin, metolachlor, and 

dimethenamid are soil-applied herbicides that provide poor to excellent kochia 

control. To be effective, these herbicides must be incorporated by mechanical tillage 

or rainfall into the top 1-2 inches of soil where weed seeds are germinating. 

However, nearly all chickpeas in Montana are grown under no-till production 

systems to conserve moisture and reduce soil erosion. Thus, mechanical 

incorporation is not a viable option and growers must rely on timely rainfall for 

proper incorporation to activate the soil-applied herbicides. Without a timely 

rainfall, the herbicides will remain on the soil surface rather than be moved into the 

top 1-2 inches of soil and will not control weeds as they germinate. It is not 

uncommon for weeds to escape the soil-applied herbicide because of lack of rainfall 

for proper incorporation. Thus, a postemergence herbicide is needed to control 

escaped weeds. Pyridate is a postemergence herbicide that will control kochia that 

are not controlled by the soil-applied herbicides. 

Imazethapyr is another soil-applied herbicide that controls kochia that is not ALSresistant. However, it is known that most kochia in North Dakota is ALS resistant. 

Thus, imazethapyr is not a viable option since most kochia is resistant to it. 

Saflufenacil is labeled for preplant use in chickpea, but does not provide residual 

control of kochia. 

Quizalofop, sethoxydim and clethodim are registered for foliar applications on 

chickpea under several product names. However, these products control only 

grasses and have no activity on kochia. 

b) Alternative Control Practices: 

Chickpea is a planted in the spring from late-April to mid-May. Kochia tends to 

emerge with the crop, but may also germinate throughout the growing season. 

Therefore, delayed seeding and/or tillage prior to seeding do not effectively provide 

season-long kochia control. Chickpea is commonly seeded in narrow rows and thus 

in-crop cultivation is not a viable alternative for weed control. Hand rogueing is cost 

prohibitive and the labor force needed for hand weeding is not available in this 

region. 
6. Efficacy of the Proposed Use Under Section 18 

Tough selectively controls many annual broad leaf weeds including kochia. Pyridate is 

more effective applied under the following conditions: 1) higher water volumes, 2) warm, 

sunny conditions, and 3) small weeds. Risks to rotational crops are minimal due to the 

short half-life and low soil persistence leading to no residual impact to subsequent crops. 

Pyridate is the only known broad leaf herbicide that can provide postemergence weed 

control without impacting chickpea yield. 

The table below shows the results of a study where kochia was not controlled by soilapplied herbicides such as Spartan and Sonalan. Dry conditions resulted in little 

herbicide incorporation and poor weed control. Tough applied postemergence provided 

excellent kochia control. Treatments without Tough could not be harvested due to 

excessive weed growth. 

Table. Kochia control in chickEeas. 

Jun 26 

Treatrnent8 Rate Tim in~b lnju!2: Kochc Colgc Yield Test wt. 

% c% control c lb/A lb/bu 

Sonalan 2 pt PPI 0 20 30 0 

Spartan I Poast 5.33 oz I 1 pt PRE / POST 0 7 13 0 

Balance 1.25 oz PRE 0 17 23 0 

Sonalan I Tough 2 pt I 1.5 pt PPI I POST 0 98 99 1666 61.2 

Tough + Poast 1.5 pt + I pt 60% 0 87 91 1284 59.3 

Tough + Poast I 1.5 pt + I pt I 45% / 0 88 91 1377 60.3 Tough + Poast 0.75 pt + I pt 75% 

Tough I 1.5 pt + 2 pt I 60% 1 4 99 99 1641 60.8 Tough + Poast 0.75 pt + I pt 75% 

Goal + NIS 0.25 lb ai + 0.25 % POST 57 87 90 1179 60.6 

Untreated 0 0 0 0 0 A/I Poast and Tough treatments applied with COC at 2 pt!A . 

hPercentages refer to % cumulative weed emergence time. 

"Koch=Kochia: Colq=Common lambsquarters 

7. Expected Residue Levels in Food: 

A permanent tolerance for pyridate of 0.1 ppm was set for chickpea. (Federal register 

Oct 7, 1998. https:l/www.gpo.gov/fdsys/pkg/FR-1998-I 0-07 /html/98-26908.htm). 

Residue trials for chickpeas were conducted by the IR-4 Program in 1996. Applications 

made in accordance with the requested provisions are not expected to result in residues of 

pyridate and its metabolites in excess of 0.1 ppm for garbanzo beans. These tolerances 

have been established by the EPA and are recorded under CFR 180.462. Secondary 

residues in meat, poultry, and eggs are not expected to result. 
8. Discussion ofRisk Information: 

On May 3, 2000 the EPA established tolerances of 0.1 ppm for residues of pyridate and 

its metabolites inion chickpeas, seed. Information regarding pyridate toxicology and 

aggregate exposure can be found in the final rule published in the Federal Register May 

3, 2000, volume 65, number 86, pages 25647-25652 (attached). 

a. Human Health 

Tough®5EC herbicide poses little potential risks to humans, domestic animals, wildlife, 

and the environment. The acute oral LD50 for male rats is > 5,000 mg/kg. The active 

ingredient has a low dermal irritation potential and a low inhalation hazard. Acute dermal 

LD50 for rabbits is > 2,000 mg/kg. Inhalation LC50 >4.37 mg./Lair. Primary dermal 

irritation study indicated it is mildly irritating to rabbit skin (EPA Health Effects Division 

of the Office of Pesticide Programs, 2000). 

The EPA concluded that residues of pyridate in drinking water do not contribute 

significantly to the aggregate acute human health risk. The acute human health risks 

resulting from exposure to pyridate in food and water are below EPA's level of concern 

for all population subgroups. As for chronic risk, the EPA also concluded that no harm 

will result from aggregate chronic exposure. 

It was also determined that pyridate is not carcinogenic in either rat or mouse, and 

therefore is not expected to pose a cancer risk to humans. 

The product label addresses the risks to worker/applicator by outlining handler 

precautions and required personal protective equipment. 

b. Potential to be found in drinking water 

The potential for exposure to residues of pyridate in drinking water is negligible due to its 

low water solubility (1.5mg/L at 20 C), strong soil adsorption (Kd = .3-26) and short 

half-life (7-21 days). Pyridate is essentially immobile in all soil types and any risks to 

surface or groundwater contamination will be negligible. 

The EPA Health Effects Division determined that pyridate does not possess the 

environmental fate parameters associated with a compound that could leach to 

groundwater. However, the parameters of its degradate indicate that under unusual 

conditions such as flooding, where anaerobic conditions persist in topsoil for up to 60 

days, the degradate could possibly leach to groundwater or run off to surface water. 

Pyridate is not listed in the EPA Pesticides in Ground Water Database, nor is there an 

EPA Maximum Containment Level or health advisory 

c. Residential Uses 

Pyridate is not registered for use in ornamentals or in residential areas. 

d. Common Mode of Action 

Pyridate is a Group 6 herbicide, HRAC Group C3 (Herbicide Resistance Action 

Committee, www.hracglobal.com). It belongs to the phenyl-pyridazine family of 
herbicides. Its site of action is inhibition photosynthesis by blocking electron transport in 

photosystem II (reactions taking place in the chloroplast thylakoid membranes). 

e. Endangered or Threatened Species 

Howellia aquatilis Water Howellia, threatened 

Spiranthes diluvialis Ute Ladies' treesses, threatened 

The use ofTough®SEC herbicide in accordance to the label in chickpea fields should not 

pose a risk to any threatened or endangered species. 

f. Beneficial Organisms 

Tough®SEC is not toxic to bees and other beneficial insects (i.e. lady beetles, predatory 

mites). See the attached EPA Environmental Fate and Effects Division (EFED) report. 

g. Fish and Aquatic Organisms 

Pyridate is considered toxic to estuarine organisms. However, due to its strong soil 

adsorption and short half-life, if applied according to the label it should not pose a risk to 

estuarine organisms (see attached EPA EFED report). The label states that this material 

should not be applied within 100 yards of any freshwater spring, directly to water, to 

areas where surface water is present, or to intertidal areas below the mean high water 

mark. 

9. Notification of Other Agencies: 

Montana Department of Public Health and Human Services, Montana Department of 

Fish, Wildlife, and Parks and tribal representatives will receive copies of request. Any 

comments will be forwarded. 

10. Notification of Registrant/Manufacturer: 

Belchim Crop Protection has been notified and their let1er of support is attached. 

11. Enforcement Progran1: 

The Montana Department of Agriculture will monitor applications of pyridate to determine 

that the conditions of the emergency exemption are correctly followed. Parameters 

monitored will include acres treated, weed control, chickpea tolerance, and any adverse 

effects that may occur. 

12. Repeat uses: 

Pyridate was previously used from 1999-2003. Pyridate was registered October 7, 1998 and 

later cancelled in 2004. 
13. Progress Toward Registration: 

Registration and tolerance were established through IR-4 by EPA. The Final Rule was 

published in the Federal Register vol. 63, No. 194, October 7, 1998 pages 53837-53844 

(attached). Tolerance was established for chickpea at 0.1 0 ppm (CFR 180.462). Product 

registration was voluntarily cancelled by the registrant (Syngenta) and the product was no 

longer marketed in the U.S. Recently, Belchim Crop Protection acquired the marketing 

rights for pyridate from Syngenta. It is understood that Belchim is working with the EPA to 

re-register pyridate in the U.S. and is seeking full registration by 2019. 

Registration and tolerance were established through the IR-4 by the EPA in October 1998. 

Tolerances were established chickpeas at 0.10 ppm (CFR 180.462). Product registration 

was voluntarily cancelled by the registrant (Syngenta) and the product was no longer 

marketed in the U.S. Recently, Belchim Crop Protection acquired the marketing rights for 

pyridate from Syngenta. It is understood that Belchim is working with the EPA to re-register 

Tough®5EC in the U.S: 

List of studies that would be required by EPA to obtain a section 3 registration 

Following the EPA pre-submission meeting of last year, the following major studies were scheduled 

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

foreseen for September 2016: 

Field soil dissipation studies in 2 soils; 

Anaerobic water/sediment study; 

Aerobic soil metabolism study; 

Seedling emergence and vegetative vigor study; 

Acute avian (passerine species) toxicity study; 

Method validation aquatic studies. 

For the other parts of the dossier reference will be made to the original pyridate registration. 

Additional info responding to: crops scheduled to be registered 

Formulation scheduled for registration: Tough®5EC (5 lb. per gallon) 

Reference will be made to the existing tolerances as set by the original pyridate registration. 

Therefore, crops targeted to be registered for the 2016 submission: 

Current tolerances as follows (ppm): Established 

Chickpea, seed ................................................... 0 .1 October 7, 1998 

Collards .............................................................. 0 .03 May 3, 2000 

Com, field, forage .............................................. 0 .03 November 18, 1992 

Com, field, grain ................................................ 0 .03 November 18, 1992 

Com, field, stover .............................................. 0 .03 November 18, 1992 

Com, pop, grain ................................................. 0 .03 November 18, 1992 

Com, pop, stover ................................................ 0 .03 November 18, 1992 

Peanut ................................................................ 0 .03 November 18, 1992 

Peppermint, tops ................................................ 0 .20 May 3, 2000 

Spearmint, tops ................................................. 0 .20 May 3, 2000 
Information Required in 40 CFR 166.20(b ): 

1. Pest(s) to be controlled: 

Kochia and ALS-resistant kochia (Kochia scoparia) 

2. Events Which Brought About the Emergency Condition: 

Glyphosate-resistant kochia: Glyphosate-resistant kochia has been identified in many 

areas of the state. Glyphosate is used in no-till production systems to control weeds just 

prior to or after planting. This glyphosate application is important to provide a clean, 

weed-free start to the season and give chickpeas a competitive advantage over the weeds. 

If kochia is not controlled due to glyphosate resistance or cold weather, then kochia will 

grow uninhibited throughout the growing season as there is no postemergence herbicide 

labeled currently. Uncontrolled kochia will reduce chickpea yield and will make harvest 

difficult. Kochia can grow to 5-6 ft tall similar to small Christmas trees. Mature kochia 

can plug and damage combines. 

Dry conditions cause poor weed control from soil-applied herbicides. Soil-applied 

herbicides such as sulfentrazone must be incorporated into the seed zone shortly after 

application to effectively control weeds as they germinate. If soil-applied herbicides are 

not incorporated by mechanical tillage or by rainfall, the herbicide will remain on the soil 

surface and will not be taken up by weed seedlings that are germinating in the top 1-2 

inches of soil. Weeds that emerge before the herbicide is adequately incorporated by a 

rainfall event typically will not be controlled. 

Sulfentrazone cannot be used on all soil tvoes: Sulfentrazone cannot be applied to coarse 

soils with less than 1.5% organic matter. High soil pH can also limit whether the crop 

can be grown. Some fields in western North Dakota have high soil pH and low organic 

matter. Chickpea grows best in western North Dakota because the crop can withstand the 

drier conditions where ascochyta disease is less prevalent. 

Thus, pyridate is needed to control kochia that has escaped control through glyphosate 

resistance or dry conditions that prevent proper incorporation of soil-applied herbicides. 
Figure 1. Kochia not controlled leads to reduced crop yield. (Minot, NO) 

High kochia infestations like those seen above would require a grower to harvest around 

dense populations, thus losing 100% yield in those areas. Growers simply cannot risk 

harvesting dense infestations because kochia will plug and severely damage the combine. 

New combines cost more than $300,000. Repairing combines cost tens of thousands of 

dollars, not to mention the time lost while repairs are made. Harvest timing is critical for 

growers to obtain optimum yield and quality. Pyridate is needed to help control kochia in 

chickpea. 

A near "zero tolerance" for glyphosate-resistant kochia is required due to its ability to roll 

and rapidly spread seed from field to field. Growers need liberty to spray kochia even if 

overall yield is not affected significantly to prevent widespread kochia distribution. In 

field research with numerous crops such as sunflower, corn, wheat, and sugarbeet, kochia 

competition has been documented to reduce crop yield by 25% to 78%. Chickpea is less 

competitive with kochia than any of these crops, meaning that yield impacts from kochia 

can be higher. Growers will spray to control weeds, not only to limit yield loss of the 

current crop, but also to prevent weed seed production that will affect future crop 

losses. Growers may not spray ifkochia is present at one plant per 10,000 sq ft, but will 

likely spray at one kochia plant per 1,000 sq ft. Again, the application may be just as 

important for preventing weed seed production as it is for preventing yield loss in the 

current crop. Kochia can produce 15,000 or more seeds per plant. 
3. Economic Analysis 

Economic Impact of Kochia in Field Crops 

The table below shows a research study where kochia was not controlled by soil-applied 

herbicides. Sonalan, Spartan, and Balance provided only 7-20% kochia control. Dry 

conditions resulted in inadequate herbicide incorporation and poor weed control. 

However, pyridate applied postemergence provided excellent kochia control. Treatments 

without pyridate could not be harvested due to excessive weed growth resulting in zero 

yield. This study shows a worst case scenario, but demonstrates the potential impact of 

kochia on yield and crop harvest. 

Table. Kochia control in chickEeas. 

Jun 26 

Treatment8 Rate Timingb lniu!l: Kochc Colgc Yield Test wt. 

% c% control C lb/A lb/bu 

Sonalan 2 pt PPT 0 20 30 0 

Spartan I Poast 5.33 oz / I pt PRE / POST 0 7 13 0 

Balance 1.25 oz PRE 0 17 23 0 

Sonalan I Tough 2 pt I 1.5 pt PPI I POST 0 98 99 1666 61.2 

Tough + Poast 1.5 pt + I pt 60% 0 87 91 1284 59.3 

Tough + Poast I 1.5 pt + I pt/ 45% / 0 88 91 1377 60.3 Tough + Poast 0.75 pt + 1 pt 75% 

Tough I 1.5 pt I 60% 1 4 99 99 1641 60.8 Tough + Poast 0.75 pt + I pt 75% 

Goal + NIS 0.25 lb ai + 0.25 % POST 57 87 90 1179 60.6 

Untreated 0 0 0 0 0A/l Poast and Tough treatments applied with COC at 2 pt!A . 

hPercentages refer to % cumulative weed emergence time. 

<Koch=Kochia; Colq=Common /ambsquarters 

Tier l Significant Economic Loss (SEL) Analysis 

For purposes of the Tier 1 analysis, the "Baseline" is theoretically a chickpea field grown in a 

normal year with no kochia present. For purposes of establishing potential chickpea yield 

without chickpea, we must at look at trials in which close to 1 00% kochia control was achieved 

with herbicide treatments. From the trial described, close to 100% was achieved with the 

treatment of Sonalan followed by Tough. This treatment will be used as the "Baseline", with a 

measured yield of 1,666 lb/ A. 

In comparison, the "Emergency" condition will be defined as an average infestation of the 

emergency pest, using the best registered alternative (Sonalan or Spartan). The measured yield 

following this treatment was 0 lb/ A. 
The difference in yield between the "emergency" and "baseline" treatments was 1,666 lb/A. 

This equates to a yield loss of 100%. This meets the SEL threshold under Tier 1. 

Baseline Emergency Change %Change 

Yield 1,666 0 1,666 -100 

(lb/A) 

Economic Benefits and Losses Expected 

Year Yield/ A* Price/Unit Gross Revenue/ A Production Cost/ A Net Revenue/ A 

2015 700 0.36 252 319 -67 

2014 1100 0.24 264 323 -59 

2013 1920 0.23 442 331 111 

2012 1350 0.30 405 330 75 

2011 1100 0.35 385 290 95 

Average 1234 0.30 350 319 31 

Year Yield/ A Price/ Unit Gross Revenue/ A Production Cost/ A Net Revenue/ A 

2016 (1) 

2016 (2) 

Difference 

1600 

1400 

0.25 

0.25 

400 

350 

(1) - Current year with the use of proposed pest idde 

(2) - Current year without the use of proposed pestidde 

*Yield and price for large kabuli chickpeas 

Sources: 

Yield: NASS 

Price: AGT 

Production Costs: NDSU Extension Ag Econ Department 

Supporting Documentation: 

1. Tough SEC Package Label 

2. Tough SEC Section 18 Supplemental Label 

3. Tough SEC MSDS 

4. Northern Pulse Growers Letter of Support 

315 

315 

85 

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