North Dakota 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 North Dakota Department of Agriculture is requesting a specific 

exemption for the use ofTough 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: 

Jerry Sauter 

Pesticide, Feed, and Fertilizer Team Leader 

ND Department of Agriculture 

600 E Boulevard, Department 602 

Bismarck, ND 58505-0020 

Phone: 701-328-2980 

E-mail: jdsauter@nd.gov 

Qualified Expert: 

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 865233 

Email: Davy. V anBerlamont@belchim .com 

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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 North Dakota 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 finer 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 

d) 

e) 

of product per acre. • • • • • • 

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Maximum Number of Applications: 

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Two applications ofT ough per growing season may be made if necessru\,.)1' wi{hl 

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. • • • 

Total Number of Acres to be Treated: 

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There were 9,600, 6,000, and 7,000 acres of chickpea in North Dakota in 2(9i3, : 

2014, and 2015, respectively. We expect up to 5,000 chickpea acres in 2016 that 

may require treatment. 

f) Total Amount of Pesticide to be Used: 

4,700 pounds active ingredient for one application. 9,400 pounds active 

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ingredient would be the maximum with two applications. 

g) Use Period: 

Aprill , 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 ofharvest. 

h) Additional Restrictions: 

(1) 

(2) 

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(4) 

(5) 

(6) 

(7) 

If this product is to be used in western Richland or eastern Ransom Counties, 

appropriate steps should be taken to minimize drift on and exposure to the 

threatened Western prairie fringed orchid (Platanthera praeclara). Infonnation on 

measures to be taken to protect the Western prairie fringed orchid can be obtained 

by contacting the North Dakota Department of Agriculture at (701) 328-2231 or 

1-(800) 242-7535 

Federal and supplemental labels address reentry and worker protection, 

environmental hazards and restrictions (see attached label). 

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

DO NOT make more than 2 applications 

DO NOT apply by air. 

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

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

susceptible vegetation. 

DO NOT allow livestock to graze on treated fields. 

DO NOT feed forage, hay or silage from treated fields to livestock. •••• • • •••• 

..... To Protect endangered plant species, one of the following options must be usoo:: • 

(I) Apply only when there is sustained wind away from wetland/transitiomtl zone !" ·: •: 

• • native plant communities, : • • • • • • •: • •: 

(2) Leave a 25-foot buffer between treatment area and wetland/transitional Z..<1If~ fliltive ••• :: . . . . . . . plant comrnurutles, or • • • • • • 

(3) Use low pressure nozzles according to manufacturer's specifications th..ns .wv.duce 

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 the North Dakota State 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 

b) 

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, all chickpeas in North Dakota 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 soilapplied 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 residttal• 

control of kochia. • •: • 

• • Quizalofop, sethoxydim and clethodim are registered for foliar applicationSOfl' • • 

chickpea under several product names. However, these products control oqiy•. •, 

grasses and have no activity on kochia. • • • 

Alternative Control Practices: 

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

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

regwn. 

6. Efficacy ofthe Proposed Use Under Section 18 

Tough selectively controlS many annual broadleaf weeds including kochia. Pyridate was 

safely used from 1999-2003 in North Dakota chickpea fields, but was voluntarily 

withdrawn from the market by the manufacturer in 2004. Pyridate provided good to 

excellent kochia control. 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 broadleaf 

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 chick~eas. 

Jun 26 

Treatmenta Rate Timingb nju~ Kochc Colgc Yield Test wt. 

% c% control c lb/A lb/bu 

Son alan 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/1.5 pt PPI I POST 0 98 99 1666 61.2 

Tough+ Poast 1.5 pt + 1 pt 60% 0 87 91 1284 59.3 

Tough+ Poastl 1.5 pt + 1 ptl 45%/ 0 88 91 1377 60.3 Tough+ Poast 0.75 pt + 1 pt 75% ..... Tough I 1.5 pt + 2 ptl 60%1 • •••• 4 99 99 1641 60.8 Tough+ Poast 0.75 pt + 1 pt 75% •••• • 

Goal + NIS 0.25 lb ai + 0.25 % POST 57 87 90 1119" • • 60.6 

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Untreated 0 0 0 o. • 8AII Poast and Tough treatments applied with COG at 2 pt/A . •••••• • 

bPercentages refer to % cumulative weed emergence time. •• • 

cKoch=Kochia; Colq=Common lambsquarters • • • •• • 

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•••• • • • •• • 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://www.gpo.gov/fdsys/pkg/FR-1998-l 0-07 /html/98-26908.htm). 

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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 of Risk Information: 

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

its metabolites in/on 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 mglkg. 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 >4.3 7 mg./L air. 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 negligiblt) ~~~ o 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 ri~&s-to 

surface or groundwater contamination will be negligible. • 0 0 

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The EPA Health Effects Division determined that pyridate does not possess the • • • 0 0 0 

environmental fate parameters associated with a compound that could leach to • • • 

groundwater. However, the parameters of its degradate indicate that under unusual" 0 0 

conditions such as flooding, where anaerobic conditions persist in topsoil for u}l ~ 

days, the de gradate could possibly leach to groundwater or run off to surface ~te~ •. 

Pyridate is not listed in the EPA Pesticides in Ground Water Database, nor is th ~ art 

EPA Maximum Containment Level or health advisory. 

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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 

See attached document 

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: 

The North Dakota Game and Fish Department, the North Dakota Department of Health, 

and the local U.S. Fish and Wildlife Service have received copies of this request. Any 

comments will be forwarded. 

10. Notification of Registrant/Manufacturer: 

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

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Enforcement Program: 

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The North Dakota Department of Agriculture will monitor applications ofpyridatet(l)•:• • 

determine that the conditions of the emergency exemption are correctly followed . ••• 

Parameters monitored will include acres treated and any adverse effects that may oeetiP." 

Repeat uses: 

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Pyridate was previously used from 1999-2003. Pyridate was registered October 7: •1499 and 

later cancelled in 2004. 

13. Progress Toward Registration: 

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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 0.10 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 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 Belchirn 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-subrnission 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 

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

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

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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 types: 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 . •••• • • •••• 

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3. 

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. 

Economic Analysis 

Economic Impact of Kochia in Field Crops 

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The table below shows a research study where kochia was not controlled by soil~a~plied 

herbicides. Sonalan, Spartan, and Balance provided only 7-20% kochia controL Dcy 

conditions resulted in inadequate herbicide incorporation and poor weed controt" " •• • 

However, pyridate applied postemergence provided excellent kochia control. lJ'e~fuents 

without pyridate could not be harvested due to excessive weed growth resulting in ze·ro 

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

kochia on yield and crop harvest. 

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Table. Kochia control in chick~eas . 

Jun 26 

Treatmenta Rate Timingb lnju~ Kochc Colgc Yield Test wt. 

% c% control c lb/A lb/bu 

Son alan 2 pt PPI 0 20 30 0 

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

Balance 1.25 oz PRE 0 17 23 0 

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

Tough+ Poast 1.5 pt + 1 pt 60% 0 87 91 1284 59.3 

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

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

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

Untreated 0 0 0 0 8AI/ Poast and Tough treatments applied with COC at 2 pt!A. 

bPercentages refer to % cumulative weed emergence time. 

cKoch=Kochia; Colq=Common lambsquarters 

Tier I Significant Economic Loss (SEL) Analysis 

For purposes of the Tier I 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 100% 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 I ,666 t-lifi\: • 

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

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Baseline Emergency Change %Change • 

Yield 1,666 0 1,666 -100 •••••• • 

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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 

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5. Belchim letter of support 

6. North Dakota Threatened and Endangered Species Risk Assessment 

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