crop-chem-docs/corpus/epa_ppls/100-603.md

# Princep® Caliber 90® HERBICIDE

- EPA Reg No: **100-603**
- Registrant: SYNGENTA CROP PROTECTION, LLC
- Signal word: Caution
- Active ingredients: Simazine (90%)
- Label accepted: 2023-11-28
- Source PDF: https://www3.epa.gov/pesticides/chem_search/ppls/000100-00603-20231128.pdf

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Notification ABN or Label Acceptable v.20220527
November 28, 2023
Mark W. White
Sr. Stewardship & Regulatory Portfolio Manager
Syngenta Crop Protection, LLC
P.O. Box 18300
Greensboro, NC 27419-8300
Subject: Notification per PR N 98-10 – Label Clarification
 Product Name: PRINCEP CALIBER 90 HERBICIDE
EPA Registration Number: 100-603
Application Date: 3/8/2023
Case Number: 477054
Dear Mark W. White:
The Agency is in receipt of your Application for Pesticide Notification under Pesticide 
Registration Notice (PRN) 98-10 for the above referenced product. The Registration Division 
(RD) has conducted a review of this request for its applicability under PRN 98-10 and finds that 
the action requested falls within the scope of PRN 98-10. 
The label submitted with the application has been stamped “NOTIFICATION” and placed in our 
records. 
Should you wish to add/retain a reference to the company’s website on your label, then please be 
aware that the website becomes labeling under the Federal Insecticide, Fungicide, and 
Rodenticide Act (FIFRA) and is subject to review by the Agency. If the website is false or 
misleading, the product would be misbranded and unlawful to sell or distribute under FIFRA 
section 12(a)(1)(E). 40 CFR 156.10(a)(5) lists examples of statements EPA may consider false or 
misleading. In addition, regardless of whether a website is referenced on your product’s label, 
claims made on the website may not substantially differ from those claims approved through the 
registration process. Therefore, should the Agency find or if it is brought to our attention that a 
website contains false or misleading statements or claims substantially differing from the EPA 
approved registration, the website will be referred to the EPA’s Office of Enforcement and 
Compliance.
If you have any questions, please contact Sarah Meadows at 202-566-2828 or at 
meadows.sarah@epa.gov.

Page 2 of 2
EPA Reg. No. 100-603
Case No. 477054
Sincerely,
Emily Schmid, Product Manager 25
Herbicide Branch
Registration Division (7505P)
Office of Pesticide Programs

[Master Label] 
Sale, use and distribution of this product in Nassau and Suffolk Counties in the 
State of New York is prohibited.
Not for use in the states of Hawaii or Alaska or in the U.S. territories (Puerto Rico, 
Guam, American Samoa, the U.S. Virgin Islands, and the North Mariana Islands).
SIMAZINE GROUP 5 HERBICIDE
Princep® Caliber 90®
[ABN: Princep® Caliber 90® CR]
Herbicide
For weed control in avocado, blueberry, caneberry, citrus fruit, grapes, olives, pome 
fruit, stone fruit, strawberry, tree nuts, corn (field, pop, sweet), Christmas trees, and 
nurseries
Active Ingredient:
Simazine: 2-chloro-4,6-bis(ethylamino)-s-triazine ................................................. 90.0%
Other Ingredients: 10.0%
Total: 100.0%
Princep Caliber 90 is a water-dispersible granule that contains 90 lb of simazine per 100 
lb of product.
KEEP OUT OF REACH OF CHILDREN.
CAUTION
See additional precautionary statements and directions for use inside booklet.
EPA Reg. No. 100-603
EPA Est. 
__________
Net Contents
[Batch Code: _____ ] (For nonrefillables only.)
100-603
11/28/2023

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FIRST AID
If on skin or 
clothing
x Take off contaminated clothing.
x Rinse skin immediately with plenty of water for 15-20 minutes.
x Call a poison control center or doctor for treatment advice.
If in eyes x Hold eye open and rinse slowly and gently with water for 15-20
minutes.
x Remove contact lenses, if present, after the first 5 minutes, then 
continue rinsing eye.
x Call a poison control center or doctor for treatment advice.
If swallowed x Call a poison control center or doctor immediately for treatment 
advice.
x Have person sip a glass of water if able to swallow.
x Do not induce vomiting unless told to do so by a poison control 
center or doctor.
x Do not give anything by mouth to an unconscious person.
If inhaled x Move person to fresh air.
x If person is not breathing, call 911 or an ambulance, then give 
artificial respiration, preferably mouth-to-mouth, if possible.
x Call a poison control center or doctor for further treatment 
advice.
Have the product container or label with you when calling a poison control center or 
doctor, or 
going for treatment.
HOTLINE NUMBER
For 24-Hour Medical Emergency Assistance (Human or Animal) or Chemical
Emergence Assistance (Spill, Leak, Fire, or Accident), Call
1-800-888-8372
PRECAUTIONARY STATEMENTS
Hazards to Humans and Domestic Animals
CAUTION
Harmful if swallowed, or absorbed through the skin. Causes moderate eye irritation.
Avoid contact with eyes, skin, or clothing.

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Personal Protective Equipment (PPE)
Mixers and loaders supporting groundboom applications must wear:
x Coveralls over long-sleeved shirt and long pants
x Chemical resistant gloves made of barrier laminate, butyl rubber •14 mils, nitrile 
rubber •14 mils, neoprene rubber •14 mils, polyvinyl chloride (PVC) •14 mils, or 
Viton® •14 mils
x Chemical-resistant footwear plus socks
x Chemical-resistant apron
x A minimum of a NIOSH-approved particulate filtering facepiece respirator with 
any N, R, or P filter; OR a NIOSH-approved elastometic particulate respirator 
with N, R, or P filter; OR a NIOSH-approved powered air purifying respirator with 
HE filters.
All other mixers, loaders, applicators, and other handlers must wear:
x Long-sleeved shirt and long pants
x Shoes plus socks
x Chemical-resistant gloves made of barrier laminate, butyl rubber •14 mils, nitrile 
rubber •14 mils, neoprene rubber •14 mils, polyvinyl chloride (PVC) •14 mils, or 
Viton •14 mils
Applications made by mechanically pressurized handguns to strawberries are restricted 
to either spot treatment only or mixer/loader/applicators must wear coveralls over long-
sleeved shirt and long pants in addition to the PPE specified above.
Mixer/loader/applicators for backpack application to grapefruit and oranges must wear 
coveralls over long-sleeved shirt and long pants in addition to the PPE specified above.
Follow manufacturer’s instructions for cleaning/maintaining PPE. If no such instructions 
for washables exist, use detergent and hot water. Keep and wash PPE separately from 
other laundry.
Discard clothing and other absorbent materials that have been drenched or heavily 
contaminated with this product’s concentrate. Do not reuse them.
Engineering Control Statements
When handlers use enclosed cabs in a manner that meets the requirements listed in the 
Worker Protection Standard (WPS) for agricultural pesticides [40 CFR 170.240(d)(4-5)], 
the handler PPE requirements may be reduced or modified as specified in the WPS.

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User Safety Recommendations
Users should:
x Wash hands before eating, drinking, chewing gum, using tobacco, or using the
toilet.
x Remove clothing/PPE immediately if pesticide gets inside. Then wash
thoroughly and put on clean clothing.
x Remove PPE immediately after handling this product. Wash the outside of
gloves before removing. As soon as possible, wash thoroughly and change
into clean clothin
g.
Environmental Hazards
Simazine can travel (seep or leach) through soil and can enter ground water which may 
be used as drinking water. Simazine has been found in ground water. Users are 
advised not to apply simazine to sand and loamy sand soils where the water table 
(ground water) is close to the surface and where these soils are very permeable; i.e., 
well-drained. Your local agricultural agencies can provide further information on the 
type of soil in your area and the location of ground water.
This pesticide is toxic to aquatic invertebrates. Do not apply directly to water, to areas 
where surface water is present, or to intertidal areas below the mean high water mark. 
Runoff and drift from treated areas may be hazardous to aquatic organisms in 
neighboring areas. Do not contaminate water when disposing of equipment wash 
water.
Product must not be mixed or loaded within 50 feet of intermittent streams and rivers, 
natural or impounded lakes and reservoirs. Product must not be applied within 66 feet 
of points where field surface water runoff enters perennial or intermittent streams and 
rivers or within 200 feet of natural or impounded lakes and reservoirs. If this product is 
applied to highly erodible land, the 66 foot buffer or setback from runoff entry points 
must be planted to crop, or seeded with grass or other suitable crop.
Product must not be mixed or loaded, or used within 50 feet of all wells, including 
abandoned wells, drainage wells, and sink holes. Operations that involve mixing, 
loading, rinsing, or washing of this product into or from pesticide handling or application
equipment or containers within 50 ft. of any well are prohibited, unless conducted on an 
impervious pad constructed to withstand the weight of the heaviest load that may be 
positioned on or moved across the pad. Such a pad shall be designed and maintained 
to contain any product spills or equipment leaks, container or equipment rinse or wash 
water, and rain water that may fall on the pad. Surface water shall not be allowed to 
either flow over or from the pad which means the pad must be self-contained. The pad 
shall be sloped to facilitate material removal. An unroofed pad shall be of sufficient 
capacity to contain at a minimum 110% of the capacity of the largest pesticide container 
or application equipment on the pad. A pad that is covered by a roof of sufficient size to 
completely exclude precipitation from contact with the pad shall have a minimum 
containment of 100% of the capacity of the largest pesticide container or application

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equipment on the pad. Containment capacities as described above shall be maintained 
at all times. The above-specified minimum containment capacities do not apply to 
vehicles when delivering pesticide to the mixing/loading sites.
Additional State imposed requirements regarding well-head setbacks and operational 
area containment must be observed.
One of the following restrictions must be used in applying simazine to tile-outletted 
terraced fields containing standpipes:
x Do not apply within 66 feet of standpipes in tile-outletted terraced fields.
x Apply this product to the entire tile-outletted terraced field and immediately 
incorporate it to a depth of 2-3 inches in the entire field.
x Apply this product to the entire tile-outletted terraced field under a no-till practice 
only when a high crop residue management practice is practiced. High crop 
residue management is described as a crop management practice where little or 
no crop residue is removed from the field during and after crop harvest.
NON-TARGET ORGANISM ADVISORY STATEMENT
This product is toxic to plants and may adversely impact the forage and habitat of non-
target organisms, including pollinators, in areas adjacent to the treated site. Protect the 
forage and habitat of non-target organisms by following label directions intended to 
minimize spray drift.

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CONDITIONS OF SALE AND LIMITATION OF WARRANTY AND LIABILITY
NOTICE: Read the entire Directions for Use and Conditions of Sale and Limitation of 
Warranty and Liability before buying or using this product. If the terms are not 
acceptable, return the product at once, unopened, and the purchase price will be 
refunded.
The Directions for Use of this product must be followed carefully. It is impossible to 
eliminate all risks inherently associated with the use of this product. Crop injury, 
ineffectiveness or other unintended consequences may result because of such factors 
as manner of use or application, weather or crop conditions, presence of other materials 
or other influencing factors in the use of the product, which are beyond the control of 
SYNGENTA CROP PROTECTION, LLC or Seller. To the extent permitted by 
applicable law, Buyer and User agree to hold SYNGENTA and Seller harmless for any 
claims relating to such factors.
SYNGENTA warrants that this product conforms to the chemical description on the label 
and is reasonably fit for the purposes stated in the Directions for Use, subject to the 
inherent risks referred to above, when used in accordance with directions under normal 
use conditions. To the extent permitted by applicable law: (1) this warranty does not 
extend to the use of the product contrary to label instructions, or under conditions not 
reasonably foreseeable to or beyond the control of Seller or SYNGENTA, and, (2) Buyer 
and User assume the risk of any such use. TO THE EXTENT PERMITTED BY 
APPLICABLE LAW, SYNGENTA MAKES NO WARRANTIES OF MERCHANTABILITY 
OR OF FITNESS FOR A PARTICULAR PURPOSE NOR ANY OTHER EXPRESS OR 
IMPLIED WARRANTY EXCEPT AS WARRANTED BY THIS LABEL.
To the extent permitted by applicable law, in no event shall SYNGENTA be liable for 
any incidental, consequential or special damages resulting from the use or handling of 
this product. TO THE EXTENT PERMITTED BY APPLICABLE LAW, THE 
EXCLUSIVE REMEDY OF THE USER OR BUYER, AND THE EXCLUSIVE LIABILITY 
OF SYNGENTA AND SELLER FOR ANY AND ALL CLAIMS, LOSSES, INJURIES 
OR DAMAGES (INCLUDING CLAIMS BASED ON BREACH OF WARRANTY, 
CONTRACT, NEGLIGENCE, TORT, STRICT LIABILITY OR OTHERWISE) 
RESULTING FROM THE USE OR HANDLING OF THIS PRODUCT, SHALL BE THE 
RETURN OF THE PURCHASE PRICE OF THE PRODUCT OR, AT THE ELECTION 
OF SYNGENTA OR SELLER, THE REPLACEMENT OF THE PRODUCT.
SYNGENTA and Seller offer this product, and Buyer and User accept it, subject to the 
foregoing Conditions of Sale and Limitation of Warranty and of Liability, which may not 
be modified except by written agreement signed by a duly authorized representative of 
SYNGENTA.

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DIRECTIONS FOR USE
It is a violation of Federal law to use this product in a manner inconsistent with its 
labeling.
Do not apply this product in a way that will contact workers or other persons, either 
directly or through drift. Only protected handlers may be in the area during application. 
For any requirements specific to your State or Tribe, consult the agency responsible for 
pesticide regulation.
ANY USE OF THIS PRODUCT IN AN AREA WHERE USE IS PROHIBITED IS A 
VIOLATION OF FEDERAL LAW. Before using this product, you must consult the 
Simazine Watershed Information Center (SWIC) to determine whether the use of this 
product is prohibited in your watershed. SWIC can be accessed through 
www.simazine-watershed.info or 1-888-365-2874. If the SWIC indicates that use of this 
product is prohibited in your watershed, you may return this product to your point of 
purchase or contact Syngenta Crop Protection, LLC for a refund.
Endangered Species
It is a Federal offense to use any pesticide in a manner that results in an unauthorized 
“take” (e.g., kill or otherwise harm) of an endangered species under the Endangered 
Species Act section 9. When using this product, you must follow the measures 
contained in the Endangered Species Protection Bulletin for the area in which you are 
applying the product. You must obtain a Bulletin no earlier than six months before using 
this product. To obtain Bulletins, consult http://www.epa.gov/espp/, call 1-844-447-3813, 
or email ESPP@epa.gov. You must use the Bulletin valid for the month in which you will 
apply the product.
AGRICULTURAL USE REQUIREMENTS
Use this product only in accordance with its labeling and with the Worker Protection 
Standard, 40 CFR part 170. This Standard contains requirements for the protection 
of agricultural workers on farms, forests, nurseries, and greenhouses, and handlers of 
agricultural pesticides. It contains requirements for training, decontamination, 
notification, and emergency assistance. It also contains specific instructions and 
exceptions pertaining to the statements on this label about personal protective 
equipment (PPE) and restricted-entry interval. The requirements in this box only 
apply to uses of this product that are covered by the Worker Protection Standard.
For Christmas trees, do not enter or allow worker entry into treated areas 
during the restricted-entry interval (REI) of 48 hours. For all other crops and 
use patterns, do not enter or allow worker entry into treated areas during the 
restricted-entry interval (REI) of 12 hours. Exception: If the product is soil-injected 
or soil-incorporated, the Worker Protection Standard, under certain circumstances, 
allows workers to enter the treated area if there will be no contact with anything that 
has been treated.

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PPE required for early entry to treated areas that is permitted under the Worker 
Protection Standard and that involves contact with anything that has been treated, 
such as plants, soil, or water is:
x Coveralls
x Chemical resistant gloves made of any waterproof material
x Shoes plus socks
Applications made by mechanically pressurized handguns are restricted to spot treatment 
only for the following uses
o Citrus (Grapefruit, Oranges, Lemons)
o Pome Fruits (Apples, Pears)
o Stone Fruits (Cherries [sweet and tart], peaches, Plums, Nectarines)
o Tree Nuts (Pecans, Walnuts, Filberts, Almonds, Macadamia Nuts)
o Berry and Small Fruit (Blueberries, Blackberries, Loganberries, Raspberries, 
Grapes, Lowbush Blueberries, Cranberries)
o Tropical and Sub-tropical Fruits (Avocado, Olive)
o Nursery/Ornamentals
o Sweet Corn
Applications made by mechanically pressurized handguns to strawberries are restricted 
to either spot treatment only or mixer/loader/applicators must wear coveralls over long-
sleeved shirt and long pants, shoes plus socks, and gloves made of barrier laminate, 
EXW\OUXEEHU•PLOVQLWULOHUXEEHU•PLOVQHRSUHQHUXEEHU•PLOVSRO\YLQ\O
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NON-AGRICULTURAL USE REQUIREMENTS
The requirements in this box apply to uses of this product that are NOT within the scope 
of the Worker Protection Standard for agricultural pesticides (40 CFR part 170). The 
WPS applies when this product is used to produce agricultural plants on farms, forests, 
nurseries, or greenhouses.
Do not enter or allow others (including children or pets) to enter treated areas 
until sprays have dried.
FAILURE TO FOLLOW THE DIRECTIONS FOR USE AND PRECAUTIONS ON THIS 
LABEL MAY RESULT IN CROP INJURY, POOR WEED CONTROL, AND/OR 
ILLEGAL RESIDUES.
USE RESTICTIONS 
Sale, use and distribution of this product in Nassau and Suffolk Counties in the 
State of New York is prohibited.
Not for use in the states of Hawaii or Alaska or in the U.S. territories (Puerto Rico, 
Guam, American Samoa, the U.S. Virgin Islands, and the North Mariana Islands).
Do not apply this product through any type of irrigation system.
All shelterbelt and forestry uses, except “Christmas Tree Plantings”, are prohibited.
This product is not for use in formulating end-use products for aquatic use or any other 
use.
PRODUCT INFORMATION
Aerial application is prohibited.
When tank mixing or sequentially applying simazine or products containing simazine, 
the total pounds of simazine applied must not exceed the specific maximum rate per 
calendar year as noted in the use directions.
Apply this herbicide before weeds emerge or after removal of weed growth. Princep 
Caliber 90 controls a wide variety of annual broadleaf and grass weeds when used at 
selective rates in agricultural crops.
Where a range of application rates is given, use the low rate on coarse-textured soil and 
soil lower in organic matter; use the high rate on fine-textured soil and soil higher in 
organic matter.

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Since this product enters weeds mainly through their roots, moisture is needed to move 
it into the root zone. Very dry soil conditions and lack of rainfall following application 
may necessitate shallow cultivation.
This product is noncorrosive to equipment, nonflammable, and has low electrical 
conductivity. 
WEED RESISTANCE MANAGEMENT
SIMAZINE GROUP
5 HERBICIDE
Princep Caliber 90 contains the active ingredient simazine which is a Group 5 herbicide 
that inhibits photosynthesis at photosystem II (PSII, Site of Action Group 5). Any weed 
population may contain plants naturally resistant to Group 5 herbicides. Such resistant 
weed plants may not be effectively managed using Group 5 herbicides but may be 
effectively managed utilizing another herbicide alone or in mixtures from a different 
Group and/or by using cultural or mechanical practices. However, a herbicide mode of 
action classification by itself may not adequately address specific weeds that are 
resistant to specific herbicides. Consult your local Syngenta representative, and/or 
agricultural advisor to determine appropriate actions for treating specific resistant 
weeds.
Principles of Herbicide Resistant Weed Management
Scout and know your field
• Know weed species present in the field to be treated through scouting and field
history. An understanding of weed biology is useful in designing a resistance
management strategy. Ensure the weed management program will control all
weeds present.
• Fields should be scouted prior to application to determine species present and
growth stage. Always apply this herbicide at the full labeled rate and correct
timing for the weeds present in the field.
Utilize non-herbicidal practices to add diversity
• Use diversified management tactics such as cover crops, mechanical weed
control, harvest weed seed control, and crop rotation as appropriate.
Use good agronomic practices, start clean and stay clean
• Use good agronomic practices that enhance crop competitiveness.
• Plant into weed-free fields utilizing tillage or an effective burndown herbicide for
control of emerged weeds.
• Sanitize farm equipment to avoid spreading seed or vegetative propagules prior
to leaving fields.

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Difficult to control weeds
• Fields with difficult to control weeds should be planted in rotation with crops that 
allow the use of herbicides with an alternative mode of action or different 
management practices.
• Difficult to control weeds may require sequential applications, such as a broad 
spectrum preemergence herbicide followed by one or more postemergence 
herbicide applications. Utilize herbicides containing different modes of action 
effective on the target weeds in sequential applications. 
Do not overuse the technology
• Do not use more than two applications of this or any other herbicide with the 
same mode of action in a single growing season unless mixed with an herbicide 
with a different mode of action which provides overlapping spectrum for difficult 
to control weeds.
Scout and inspect fields following application
• Prevent an influx of weeds into the field by controlling weeds in field borders.
• Scout fields after application to verify that the treatment was effective.
• Suspected- herbicide resistant weeds may be identified by these indicators
• Failure to control a weed species normally controlled by the herbicide at 
the dose applied, especially if control is achieved on adjacent weeds;
• A spreading patch of non-controlled plants of a particular weed species; 
and
• Surviving plants mixed with controlled individuals of the same species.
• Report non-performance of this product to your Syngenta retailer, Syngenta 
representative, or call 1-866-Syngent(a) (866-796-4368). If resistance is 
suspected ensure weed escapes are controlled using an herbicide with an 
effective mode of action and/or use non-chemical means to prevent further seed 
production.
Prevent weed escapes before, during, and after harvest
• Do not allow weed escapes to produce seed or vegetative structures such as 
tubers or stolons which contribute to spread and survival. Consider harvest 
weed seed management and control weeds postharvest to prevent seed 
production.

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Resistant Weeds
x Contact your local Syngenta representative, retailer, crop advisor or extension agent 
to determine if weeds resistant to this mode of action are present in your area. If 
resistant biotypes have been reported, use the full labeled rate of this product, apply 
at the labeled timing, and tank-mix with a different mode of action product so there 
are multiple effective modes of application for each suspected resistant weed. 
PERENNIAL CROP REPLANTING
If replanting perennial crops, do not apply Princep Caliber 90 in the year preceding 
planting these crops, unless otherwise stated on this label, or crop injury may occur.
APPLICATION PROCEDURES
Ground boom applications: Use conventional ground sprayers equipped with nozzles 
that provide accurate and uniform application. Be certain that nozzles are uniformly 
spaced and are the same size. Calibrate sprayer before use and recalibrate at the start 
of each season and when changing carriers. Unless otherwise specified, use a 
minimum of 20 gallons of spray mixture per acre.
Use a pump with capacity to: (1) maintain 35-40 psi at nozzles, (2) provide sufficient 
agitation in tank to keep mixture in suspension, and (3) to provide a minimum of 20% 
bypass at all times. Use centrifugal pumps which provide propeller shear action for 
dispersing and mixing this product. The pump should provide a minimum of 10 
gals./minute/100 gal. tank size circulated through a correctly positioned sparger tube or 
jets.
Use screens to protect the pump and to prevent nozzles from clogging. Screens placed 
on suction side of pump should be 16-mesh or coarser. Do not place a screen in the 
recirculation line. Use 50-mesh or coarser screens between the pump and boom, and 
where required, at the nozzles. Check nozzle manufacturer’s recommendations.
For band applications, calculate amount to be applied per acre as follows:
band width in inches
X broadcast rate = amount needed
row width in inches per acre per acre of field
MANDATORY SPRAY DRIFT MANAGEMENT
Ground boom applications:
x User must only apply with the release height recommended by the manufacturer, 
but no more than 4 feet above the ground or crop canopy.
x Applicators are required to use a coarse or coarser droplet size (ASABE S572)
x Do not apply when wind speeds exceed 10 miles per hour at the application site.

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x Do not apply during temperature inversions.
x User must maintain a 15 foot (4.6 meter) in-field downwind buffer (in the direction 
in which the wind is blowing) from the edge of streams and rivers, as well as high-
tide line for all estuarine/marine environments.
SPRAY DRIFT ADVISORIES
THE APPLICATOR IS RESPONSIBLE FOR AVOIDING OFF-SITE SPRAY DRIFT. BE 
AWARE OF NEARBY NON-TARGET SITES AND ENVIRONMENTAL CONDITIONS.
IMPORTANCE OF DROPLET SIZE
An effective way to reduce spray drift is to apply large droplets. Use the largest droplets 
that provide target pest control. While applying larger droplets will reduce spray drift, the 
potential for drift will be greater if applications are made improperly or under unfavorable 
environmental conditions.
Controlling Droplet Size – Ground Boom
x Volume – Increasing the spray volume so that larger droplets are produced will reduce 
spray drift. Use the highest practical spray volume for the application. If a greater 
spray volume is needed, consider using a nozzle with a higher flow rate.
x Pressure – Use the lowest spray pressure recommended for the nozzle to produce 
the target spray volume and droplet size.
x Spray nozzle – Use a spray nozzle that is designed for the intended application. 
Consider using nozzles designed to reduce spray drift.
BOOM HEIGHT – Ground Boom
For ground equipment, the boom should remain level with the crop and have minimal 
bounce.
SHIELDED SPRAYERS
Shielding the boom or individual nozzles can reduce spray drift. Consider using shielded 
sprayers. Verify that the shields are not interfering with the uniform deposition of the 
spray on the target area.
TEMPERATURE AND HUMIDITY
When making applications in hot and dry conditions, use larger droplets to reduce effects 
of evaporation.
TEMPERATURE INVERSIONS
Drift potential is high during a temperature inversion. Temperature inversions are 
characterized by increasing temperature with altitude and are common on nights with 
limited cloud cover and light to no wind. The presence of an inversion can be indicated 
by ground fog or by the movement of smoke from a ground source or an aircraft smoke 
generator. Smoke that layers and moves laterally in a concentrated cloud (under low

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wind conditions) indicates an inversion, while smoke that moves upward and rapidly 
dissipates indicates good vertical air mixing. 
WIND
Drift potential generally increases with wind speed. AVOID APPLICATIONS DURING 
GUSTY WIND CONDITIONS. Applicators need to be familiar with local wind patterns 
and terrain that could affect spray drift.
HANDHELD TECHNOLOGY APPLICATIONS
Take precautions to minimize spray drift.
MIXING PROCEDURES
All Uses: (1) Be sure sprayer is clean and not contaminated with any other materials, 
as crop injury or sprayer clogging may result. (2) Fill tank ¼ full with clean water, 
nitrogen solution, or complete fluid fertilizer. (3) Start agitation. (4) Be certain that the 
agitation system is working properly and creates a rippling or rolling action on the liquid 
surface. (5) Pour product directly from bag into tank. (6) Continue filling tank until 90% 
full. Increase agitation if necessary to maintain surface action. (7) Add tank mix 
herbicide(s) after this product is thoroughly suspended. (8) Finish filling tank. Maintain 
agitation to avoid separation of materials. (9) Empty tank as completely as possible 
before refilling to prevent buildup of emulsifiable concentrate residue from possible tank 
mix herbicides. (10) If an emulsifiable concentrate film starts to build up in tank, drain it 
and clean with strong detergent solution or solvent. (11) Clean sprayer thoroughly 
immediately after use by flushing system with water containing a detergent.
Compatibility test: To determine the tank mix compatibility of Princep Caliber 90 with 
liquid fertilizer, crop oil, spreaders, or recommended pesticides, use this test method. 
Nitrogen solutions or complete fluid fertilizers may replace all or part of the water in the 
spray in corn. Since liquid fertilizers can vary, even within the same analysis, check 
compatibility each time before use. Be especially careful when using complete
suspension or fluid fertilizers, as serious compatibility problems are more apt to occur. 
Commercial application equipment may improve compatibility in some instances. 
Check compatibility using this procedure:
1. Add 1 pt of fertilizer to each of 2 one-qt glass jars with tight lids.
2. To one of the jars, add ¼ tsp of a compatibility agent approved for this use (¼
tsp. is equivalent to 2 pt/100 gal spray). Cap and shake until mixed. Examples 
of compatibility agents include Compex® and Unite®.
3. To both jars, add the appropriate amount of herbicide(s). If more than one 
herbicide is used, add them separately with dry herbicides first, flowables next, 
and emulsifiable concentrates last. After each addition, cap and shake until

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thoroughly mixed. The appropriate amount of herbicides for this test follows
(assuming a spray volume of 25 gal/A):
Dry herbicides: For each pound per acre, add 1.5 teaspoons to each 
jar. Fluff up wettable powder products before 
measurin
g.
Liquid herbicides: For each pint per acre, add 0.5 teaspoon to each jar.
For a spray volume other than 25 gal/A, change the teaspoons added to each jar 
as follows:
25 gal X no. teaspoons given above = teaspoons to add
desired gal spray volume per acre to each jar
4. After adding all ingredients, put lids on and tighten. Shake jars vigorously one 
minute. Let the mixtures stand 15 minutes and then look for separation, large 
flakes, precipitates, grease, gels, medium to heavy oily film on the jar, or other 
signs of incompatibility. Determine if the compatibility agent is needed in the 
spray mixture by comparing the 2 jars. If either mixture separates, but can be 
remixed readily, the mixture probably can be sprayed as long as good agitation is 
used. If the mixtures are incompatible, test the following methods of improving 
compatibility: (A) slurry the dry herbicide(s) in water before addition, or (B) add 
½ of the compatibility agent to the fertilizer and the other ½ to the emulsifiable 
concentrate or flowable herbicide before addition to the mixture. If still 
incompatible, do not use the materials mixed in the same spray tank.
WEEDS CONTROLLED
Princep Caliber 90 applied as directed in this label will control or partially control the 
weeds listed in Table 1. Optimal weed control can be obtained if Princep Caliber 90 is 
applied according to all label use directions. 
Princep Caliber 90 will not control emerged weeds so applications must be made to a 
weed-free soil surface or in tank mixture with products that provide postemergence 
control of weeds present at the time of application.
Dry weather following application of Princep Caliber 90 may reduce residual weed 
control effectiveness.
Refer to the crop sections on this label for specific rates and use directions.

-16-
Table 1. Annual Weeds Controlled
ANNUAL GRASSES BROADLEAF WEEDS
Barnyardgrass Al yssum Mustard, wild
Bluegrass, annual Burclover Nightshade species, 
annual
Brome, downy (cheatgrass) Carelessweed Paintbrush, Flora's
Crabgrass species Carpetweed Pepperweed
Fescue, rattail Chickweed, common Pepperweed, yellow flower
Foxtail species Fiddleneck Pi gweed species
Goosegrass Filaree Pineappleweed
Hairgrass, silver Fireweed Purslane, common
Junglerice Fivehook, bassia Pusle y, Florida
Oats, wild Groundsel Ra gweed, species
Fall panicum Henbit Redmaids
Ryegrass, annual Knawel (German moss) Shepherdspurse
Signalgrass species Lambsquarters, common Smartweed species, 
annual
Witchgrass Lettuce, prickl y Spanishneedles
Morningglory, species, 
annual
Speedwell
Mustard, tansy Thistle, Russian
CROP USE DIRECTIONS
AVOCADO
Apply Princep Caliber 90 to the grove floor avoiding contact with fruit, foliage, stems or 
trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Restrictions
Avocado 2.2-4.4 Following final grove 
preparation
(See “Precautions” 
for grove 
establishment 
interval before 
application)
x Apply to avocados in California 
and Florida only.
x Do not apply more than 4.4 lb/A
(4 lb ai/A) per calendar year.
x Do not make more than one 
application per calendar year.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment onl
y.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.

-17-
Precautions to reduce avocado crop injury risk:
1. Apply only to groves that have been established for 12 months or more.
2. Avoid use on sand, sandy loam or loamy sand soil.
3. Immediately following application, limit irrigation to ½ inch.
BLUEBERRIES AND CANEBERRIES
Apply Princep Caliber 90 to the orchard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Remarks
Blueberries
Blackberries
Boysenberries
Loganberries
Raspberries
2.2-4.4 x Spring
x Spring and Fall
(See “Precautions” 
for orchard 
establishment 
interval before 
application)
To control quackgrass, apply 4.4 lb/A 
(4 lb ai/A) in the fall or split the 
application by applying 2.2 lb/A in the 
fall followed by 2.2 lb/A in the spring 
when quackgrass is actively growing.
Restrictions
x Do not apply more than 4.4 lb/A (4 
lb ai/A) per calendar year.
x Do not make more than two 
applications per calendar year.
x Allow a minimum of 90 days 
between applications.
x Do not apply when fruit is present.
x Apply in a minimum of 40 gal of 
water per acre.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment only.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
Precautions to reduce crop injury risk:
1. On plantings less than 6 months old, use ½ the specified rate.
2. Avoid use on sand, sandy loam or loamy sand soils.
3. Immediately following application, limit irrigation to ½ inch.

-18-
CITRUS FRUIT
Apply Princep Caliber 90 to the orchard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
For Use In Crop
Rate1
(lb/A)
Application 
Timing Restrictions
Arizona only Orange
Grapefruit 
Lemon
Lime
Tangerine
Kumquat
Mandarin
Pummelo
Satsuma
Cultivars, 
varieties, 
and/or 
hybrids of 
these
2.2 x Spring
x Fall
x Spring and Fall
(See 
“Precautions for 
orchard 
establishment 
before 
application)
x Do not apply more than 4.4 
lb/A (4 lb ai/A) per calendar 
year.
x Do not apply more than 2.2 
lb/A (2 lb ai/A) per application.
x Do not make more than two 
applications per calendar 
year.
x Allow a minimum of 40 days 
between applications.
x Do not harvest crop for 1 day 
following application.
x Do not use in nurseries or 
apply to bedded lemons or 
oranges.
x Applications made by 
mechanically pressurized 
handguns are restricted to 
spot treatment onl
y.
California and 
Texas only
Orange
Grapefruit
Lemon
Lime
Tangerine
Calamondin
Citron
Citrus 
hybrids
Kumquat
Mandarin
Pummelo
Tangelo
Tangor
Cultivars
varieties, 
and/or 
hybrids of 
these
2.2-4.4 x Spring
x Fall
x Spring and Fall
x Do not apply more than 4.4 
lb/A (4 lb ai/A) per calendar 
year.
x Do not make more than two 
applications per calendar 
year.
x Allow a minimum of 40 days 
between applications.
x Do not harvest crop for 1 day 
following application.
x Do not use in nurseries or 
apply to bedded grapefruit, 
lemons or oranges.
x Do not use in the Imperial, 
Coachella or Palo Verde 
Valleys, or crop injury may 
occur.
x Applications made by 
mechanically pressurized 
handguns are restricted to 
spot treatment onl
y.

-19-
Florida2
only
Orange
Grapefruit
Lemon
Lime
Tangerine
Calamondin
Citron
Citrus 
hybrids
Kumquat
Mandarin
Pummelo
Satsuma
Tangelo
Tangor
Cultivars
varieties, 
and/or 
hybrids of 
these
4.4 x Spring
x Fall
x Spring and Fall
x Do not apply more than 8.8 
lb/A (8 lb a./A) per calendar 
year.
x Do not apply more than 4.4 
lb/A (4 lb ai/A) per application.
x Do not make more than two 
applications per calendar 
year.
x Allow a minimum of 40 days 
between applications.
x Do not harvest crop for 1 day 
following application.
x Do not use in nurseries.
x Applications made by 
mechanically pressurized 
handguns are restricted to 
spot treatment only.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
2For additional weed control, refer to the Difficult to Control Weeds section below.
Precautions to reduce citrus crop injury risk in all states:
1. Dark-red grapefruit hybrids, e.g. “Star Ruby”, have a higher risk of crop injury 
than non-dark red types.
Restrictions to reduce citrus crop injury risk in all states:
1. Do not exceed 4.4 lb/A/year of Princep Caliber 90 (4 lbs. ai/A) on grove planted 
trees 1 year old or less or crop injury may occur.
2. Do not apply to bedded citrus (except for FL grapefruit and oranges)
3. Do not apply to trees under stress from freeze damage for one year after the 
freeze.
Difficult to Control Weeds 
For control of difficult species, such as balsamapple vine and spanishneedles, and 
partial control of honeyvine milkweed, apply no more than 8.8 lb of Princep Caliber 90
(8.0 lb ai/A) per treated acre as a single application in the spring using a 50% band 
application. The amount of Princep Caliber 90 applied per acre of field must not exceed 
4.4 pounds (4.0 lb ai/A). Apply in the spring growing season between January and April. 
Do not make a fall application if this treatment was used in the spring.

-20-
GRAPES
Apply Princep Caliber 90 to the vineyard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Restrictions
Grapes 2.2-4.4 After harvest through 
early spring
(See “Precautions” for 
vineyard 
establishment interval 
before application)
x Do not apply more than 4.4 lb/A
(4 lb ai/A) per calendar year.
x Do not make more than one
application per calendar year.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment only.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
Precautions to reduce crop injury risk:
1. Apply only to vine where trees have been established 36 months or more or crop 
injury may occur.
2. Avoid use on sand, sandy loam or loamy sand soils.
3. Immediately following application, limit irrigation to ½ inch.
OLIVES
Apply Princep Caliber 90 to the orchard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Restrictions
Olives 2.2-4.4 Following grove 
preparation in the fall
(See “Precautions” 
for orchard 
establishment 
interval before 
application)
x Do not apply more than 4.4 lb/A
(4 lb. ai/A) per calendar year.
x Do not make more than one 
application per calendar year.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment only.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
Precautions to reduce crop injury risk:
1. Apply only to vineyards where trees have been established 12 months or more.
2. Avoid use on sand, sandy loam or loamy sand soils.
3. Immediately following application, limit irrigation to ½ inch.

-21-
POME FRUIT
Apply Princep Caliber 90 to the orchard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Restrictions
Apple
Pear
Azarole
Chinese quince
Japanese
quince
Loquat
Mayhaw
Medlar
Quince
Tejocote
Cultivars
varieties and/or 
h
ybrids of these.
2.2-4.4 Spring or Fall
(See “Precautions” 
for orchard 
establishment 
interval before 
application)
x Do not apply more than 4.4 lb/A
(4 lb ai/A) per calendar year.
x Do not make more than one 
application per calendar year.
x Do not harvest crop for 21 days 
following application
o except apples have a pre-
harvest interval of 150 days.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment only.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
Precautions to reduce apple and pear crop injury risk:
1. Apply only to orchards where trees have been established 12 months or more.
2. Avoid use on sand, sandy loam or loamy sand soils.
3. Immediately following application, limit irrigation to ½ inch.

-22-
STONE FRUIT
Apply Princep Caliber 90 to the orchard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Restrictions 
Cherry, Sweet
Cherry, Tart
Peach
Apricot
Nectarine2
Plum
Plumcot
Prune (fresh)
2.2-4.4 Spring or Fall x Do not apply more than 4.4 lb/A
(4 lba./A) per calendar year.
x Do not make more than one 
application per calendar year.
x Do not apply more than 2.2 lb/A
(2 lb ai/A) per calendar year to 
nectarines.
x Do not apply more than 2.2 lb/A
(2 lb ai/A) per calendar year to 
peaches grown in California.
x Do not harvest crop for 21 days 
following application.
x Do not apply to plums, apricots, 
plumcots or prunes (fresh) in 
California.
x Use on sweet cherry and plum is 
restricted to states east of the 
Mississippi River and the state of 
Missouri.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment onl
y.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
2Use is restricted to California, must be applied in a 2-4 foot band on each side of tree row.
Precautions to reduce crop injury risk:
1. Apply only to orchards where trees have been established 24 months or more.
2. Avoid use on sand, sandy loam or loamy sand soils with less than 1% organic 
matter.
3. Immediately following application, limit irrigation to ½ inch.
4. Do not plant nectarines or peaches into treated soil for 12 months following 
application.

-23-
STRAWBERRY(OR AND WA ONLY)
Apply Princep Caliber 90 to control or suppress the weeds listed in Table 1. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate(lb/A) Application Timing Restrictions
Strawberry 1.1 x Fall after harvest1
x Spring during 
crop dormancy
x Do not apply more than 1.1 lb/A 
(1 lb ai/A) per calendar year.
x Do not make more than one 
application per calendar year.
x Do not apply within 4 months 
after transplanting.
x Applications made by 
mechanically pressurized 
handguns are restricted to either 
spot treatment only or 
mixer/loader/applicators are 
required to wear coveralls over 
long sleeve shirts and long pants 
of clothin
g. 
1In fields where overhead irrigation is used to activate this product, apply after harvest at time of bed 
renovation. In fields where overhead irrigation is not available, apply during early October through 
November.
Precautions to reduce strawberry crop injury risk:
1. Avoid use on sand, sandy loam or loamy sand soils.
TREE NUTS
Apply Princep Caliber 90 to the orchard floor avoiding contact with fruit, foliage, stems 
or trunk. Refer to Table 1 for a list of weeds controlled or partially controlled. Refer to 
Table 2 for a list of potential tank mixtures.
Crop Rate 1 (lb/A) Application Timing Restrictions
Almond
Pecan
Walnut
1.1-2.2 Spring or Fall
(See “Precautions” 
for orchard 
establishment 
interval before 
application)
x Do not apply more than 2.2 lb/A
(2 lb ai/A) per calendar year.
x Do not make more than one 
application per calendar year.
x Do not treat the Mission variety of 
almonds.
x Do not apply to almond trees 
propagated on plum rootstocks.
x Do not harvest crop for 30 days 
followin
g application.

-24-
x Do not use on pecans west of the 
Pecos River in TX or in AZ, CA or 
NM.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment only.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
Precautions to reduce Almond crop injury risk:
1. Apply only to trees established in the grove for 24 months or more.
2. Avoid use on sand, sandy loam or loamy sand soils with less than 1% organic 
matter.
3. Immediately following application, limit irrigation to ½ inch.
4. Do not plant almond into treated soil for 12 months after application.
Crop2
Rate1
(lb/A) Application Timing Restrictions
Beech Nut
Brazil Nut
Butternut
Cashew
Chestnut
Chinquapin
Filbert/Hazelnut
Hickory Nut
Macadamia Nut
2.2-4.4 x Spring
x Fall
x Spring and Fall
(See “Precautions” 
for orchard 
establishment 
interval before 
application)
x Do not apply more than 4.4 lb/A (4 
lb ai/A) per calendar year.
x Do not make more than two 
applications per calendar year.
x Allow a minimum of 120 days 
between applications.
x Do not harvest crop for 30 days 
following application.
x Do not use on Beech Nut, Brazil 
Nut, Butternut, Cashew, Chestnut, 
Chinquapin, or Hickory Nut in the 
state of California.
x Applications made by 
mechanically pressurized 
handguns are restricted to spot 
treatment only.
x Do not apply when nuts are on the 
ground during the harvest period, 
as ille
gal residues may result.
1Rates are based on a broadcast treatment acre. For band applications, reduce the broadcast rate of 
Princep Caliber 90 and water per acre in proportion to the area actually sprayed.
2Do not apply when nuts are on the ground during harvest period.
Precautions to reduce filbert, macadamia nut, pecan and walnut crop injury risk:
1. Apply only to orchards where trees have been established 36 months or more.
2. Avoid use on sand, sandy loam or loamy sand soils.
3. Immediately following application, limit irrigation to ½ inch.

-25- 
TANK MIXTURES FOR PERENNIAL FRUIT AND NUT CROPS
Princep Caliber 90 may be tank mixed with other registered herbicides for improved 
spectrum of weed control in many crops. Additionally these tank mixtures can be used 
to include a different mode of action herbicide to help control or manage the 
development of resistant weed biotypes.
Refer to the specific crop sections of this label for details on application timing, use rate 
precautions, restrictions and other use information.
Not all of the tank mixture partners listed below are registered for use on all crops listed 
on this label so read and follow all label directions of the mixture partner.
Table 2. Princep Caliber 90 Tank Mixtures for Weed Control in Perennial Crops
Tank Mix Partner
1 Directions
Gramoxone® 
brands that are 
registered for use 
on crops listed on 
this label
x Apply this tank mixture for control of emerged annual weeds at
the time of application.
x This combination is also effective for top kill and suppression of
perennial weeds.
x This mixture will provide residual control or suppression of the
weeds listed in Table 1.
x Refer to the Gramoxone brand(s) label(s) for adjuvant
instructions.
Solo glyphosate 
brands that are 
registered for use 
on crops listed on 
this label
x Apply this tank mixture for control of existing annual weeds at
the time of application.
x This combination is also effective for top control or suppression
of perennial weeds.
x This mixture will provide residual control or suppression of the
weeds listed in Table 1.
x Refer to the specific solo glyphosate brand label for adjuvant
instructions.
Solicam® or other 
solo norflurazon 
brands that are 
registered for use 
on crops listed on 
this label
x Use this mixture for improved residual control of weeds such as
clover, cutleaf evening-primrose, dandelion, henbit, horseweed
(marestail), lambsquarters, and puncturevine.
x Keep this tank mixture from contacting foliage, fruits and stems
during application.
x The tank mixture of Princep Caliber 90 + Solicam or other solo
norflurazon brands can also be applied with solo glyphosate
brands or Gramoxone brands.
Surflan® or other 
solo oryzalin 
brands that are 
registered for use 
x Use this mixture for additional residual weed control.
x The tank mixture of Princep 4L + Surflan or other solo oryzalin
brands can also be applied with solo glyphosate brands or
Gramoxone brands.

-26- 
Tank Mix Partner1 Directions
on crops listed on 
this label
Rely® or other solo 
glufosinate brands 
that are registered 
for use on crops 
listed on this label
x Apply this tank mixture for control of existing annual weeds at
the time of application.
x This combination is also effective for top control or suppression
of perennial weeds.
x This mixture will provide residual control or suppression of the
weeds listed in Table 1.
1Refer to individual product labels for precautionary statements, restrictions, rates, adjuvants and/or 
surfactants, approved uses, labeled crops and a list of weeds controlled.
CORN (FIELD, POP AND SWEET)
Apply a maximum of 2.2 lb Princep Caliber 90/A (2.0 lb ai/A) as a single preemergence 
application on soils that are not highly erodible or on highly erodible soils, as defined by 
the Natural Resources Conservation Service, if at least 30% of the soil is covered with 
plant residues. If a second treatment is required following an earlier herbicide 
application, the total simazine applied may not exceed 2.5 lbs. a.i./A per calendar year.
Apply a maximum of 1.77 lb Princep Caliber 90/A (1.6 lb ai/A) as a single preemergence 
application on highly erodible soils if <30% of the soil is covered with plant residues.
Pre-grazing/pre-harvest interval for field corn: 60 days
Pre-grazing/pre-harvest interval for popcorn: 60 days
Pre-grazing/pre-harvest interval for sweet corn: 45 days
Nitrogen solutions or complete fluid fertilizers may replace all or part of the water as a 
carrier in the spray. Determine the physical compatibility of this product with fertilizer 
before use. Refer to the Product Information section of this label for a compatibility 
test. Do not apply after corn has emerged, as there is danger of liquid fertilizers causing 
crop injury.
Preemergence: Apply before weeds and corn emerge. Use the specified rate as 
stated above. 
Preplant: Apply in the spring at the specified rate as stated above. If soil is tilled or 
worked after application, avoid deep incorporation. Best results will be obtained when 
this product is applied within 2 weeks before planting. Under dry weather conditions, 
preplant applications may give better weed control. If weeds develop, particularly under 
relatively dry conditions, a shallow cultivation will generally result in better weed control.

-27-
Winter Annual Broadleaf Control - Preemergence Fall Application
For preemergence control of winter annual weeds, such as common chickweed, henbit, 
shepherdspurse, tansymustard, wild mustard, annual bluegrass, downy brome, and 
others, broadcast 1.1 lb/A of Princep Caliber 90 after harvest of the preceding crop and
prior to weed emergence on land to be planted to corn the following year. A tillage 
operation may precede the application. Do not apply to frozen ground. If Princep 
Caliber 90 is used in the fall corn weed control program, do not exceed 1.67 lb of 
Princep Caliber 90 preemergence in the spring.
Restrictions:(1) Do not apply more than 2.77 lb/A Princep Caliber 90 to corn per 
calendar year. (2) Do not rotate to any crop except corn until the following year (3) Do 
not graze or harvest field corn or popcorn for 60 days following application. (4) Do not 
graze or harvest sweet corn for 45 days following application. (5) Do not apply preplant 
incorporated in corn in the High Plains and Intermountain areas of the West (including 
central and western KS, western NE, western OK, and the Panhandle of TX) where 
rainfall is sparse and erratic or where irrigation is required. (6) Do not plant sugar beets, 
tobacco, vegetables (including dry beans), spring-seeded small grains, or small-seeded 
legumes and grasses the year after an application, or injury may occur. (7) Applications 
made to sweet corn by mechanically pressurized handguns are restricted to spot 
treatment only.
Precautions: (1) After harvest, plow and thoroughly till the soil in fall or spring to 
minimize possible injury to spring-seeded rotational crops, regardless of the rate used. 
(2) In the High Plains and Intermountain areas of the West where rainfall is sparse and 
erratic or where irrigation is required, use this product to control weeds in corn only
when corn is to follow corn or when a crop of untreated corn is to precede another 
rotational crop. (3) Injury may occur to soybeans planted in north-central and northwest 
IA, south-central and southwest MN, northeast NE, southeast SD, and other areas the
year following application on soils having a calcareous surface layer. 
Tank Mixtures on Corn
AAtrex® or other solo atrazine-containing products: Use this product in a preplant 
or preemergence tank mixture with AAtrex brands or other solo atrazine containing 
products for control of many annual weeds, including carpetweed, crabgrass, fall 
panicum, foxtail, lambsquarters, morningglory, pigweed, ragweed, and velvetleaf.
When tank mixing or sequentially applying simazine and/or products containing either 
active ingredient to corn, the total pounds of simazine and/or atrazine applied must not
exceed 2.5 lb ai/acre per calendar year.
Refer to the AAtrex or other solo atrazine containing product label for complete 
directions. Also refer to the AAtrex or other solo atrazine containing product label and 
the Corn section of this label for precautions and restrictions.

-28-
Gramoxone brands: Use in a tank mixture where corn will be planted directly in a 
cover crop, established sod, or previous crop residues. This combination controls 
existing vegetation and provides residual control of the annual broadleaf and grass 
weeds listed in Table 1.
Add this product to the spray tank, mix thoroughly with water, and then add Gramoxone 
brandsand a nonionic surfactant. Provide constant agitation during mixing and 
application to keep the mixture in suspension.
Apply a maximum of 1.77 lb Princep Caliber 90/A (1.6 lb ai/A) as a single preemergence 
application on highly erodible soils if <30% of the soil is covered with plant residues.
Apply up to 2.2 lb of this product plus the specified labeled rate of the Gramoxonebrand
in 20-60 gal of water per acre as a broadcast spray either before or after planting, but 
before corn emerges. Add a nonionic surfactant at the rate of 0.5 pt/100 gal of spray 
volume.
For further information, see product information, caution and warning statements, 
precautions, restrictions and notes on the Princep Caliber 90 and the Gramoxone brand
labels.
NURSERIES, CHRISTMAS TREE PLANTINGS
Nurseries
Apply 2.2-3.3 lb of Princep Caliber 90 per acre in fall or spring. Refer to Table 1 for a 
list of weeds controlled or suppressed. Refer to Table 3 for a list of nursery species that 
can be treated with Princep Caliber 90. To avoid crop injury, do not apply for at least
one year after transplanting.
Restrictions for Use in Nurseries:
1. Do not apply more than 3.3 lb of Princep Caliber 90 (3 lb ai/A) per calendar year.
2. Do not apply more than once per calendar year.
3. Applications made by mechanically pressurized handguns are restricted to spot 
treatment only.
Christmas Tree Plantings 
Remove or control weed growth before Princep Caliber 90 application. Apply 2.2-4.4 
pounds of Princep Caliber 90 per acre after transplanting. Use the same rate for annual 
maintenance applications.
For quackgrass control, apply 4.4 lb/A of Princep Caliber 90 (4 lb ai/A) in the fall or 
apply a split application of 2.2 lb/A Princep Caliber 90 (2 lb ai/A) in the fall plus 2.2 lb/A 
Princep Caliber 90 (2 lb ai/A) in early spring, after quackgrass begins growth.

-29-
Refer to Table 1 for a list of weeds controlled or suppressed. Refer to Table 3 for 
Christmas tree species that can be treated with Princep Caliber 90.
Restrictions for use in Christmas Trees :
1. Do not apply more than 4.4 lb of Princep Caliber 90 (4 lb ai/A) per calendar year.
2. Do not apply more than twice per calendar year.
3. Applications made by mechanically pressurized handguns are restricted to spot 
treatment only.
Precautions to avoid or tree injury:
1. Do not use Princep Caliber 90 on seedbeds or cuttingbeds.
2. In California, Oregon, and Washington do not apply to Christmas trees sooner 
than one year after transplanting. In other areas, do not apply to Christmas tree 
transplants less than 2 years of age.
3. Do not use until soil is firmly settled around roots.
Table 3. Trees and shrubs that can be treated with Princep Caliber 90
CONIFERS
Arborvitae
Austrian pine
Bishop pine
Knobcone pine
Lodgepole pine (shore pine)
Monterey pine
Mugho pine
Red pine (Norway pine)
Scotch pine
White pine
Blue spruce
Norway spruce
Red spruce
White spruce
Balsam fir
Douglas fir
Fraser fir
White fir
Hemlock
Juniper
Red cedar
White cedar
Yew (Taxus spp.)

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Princep Caliber 90 Plus
Surflan or other solo oryzalin brands on Christmas Trees: Use this tank mix for 
additional preemergence control of weeds listed on this label and the Surflan label or 
other solo oryzalin brand labels that are registered for use on Christmas trees. Refer to 
Surflan or other solo oryzalin brand labels for use rates, precautions and restrictions. 
Use on field grown conifer species listed on the labels for each herbicide plus grand fir, 
alpine fir, Engelmann spruce, black spruce, Colorado blue spruce, Coulter pine, giant 
redwood, and Veitchi fir. 
Apply in sufficient water per acre to uniformly treat the area. Follow overtop sprays with 
sprinkler irrigation to move the herbicide from leaf surfaces to the soil. Remove weed 
growth before application. Mix weed residues, prunings, or trash into the soil, or 
remove them before treatment. Soil should be in good tilth and free of clods at time of 
application. Shallow cultivation (1-2 inches) after treatment will not reduce weed 
control. Observe all precautions and restrictions on the Princep Caliber 90 and Surflan 
label or other solo oryzalin brand label.
Note: Length of weed control may be reduced when continuous wet soil conditions 
follow herbicide application.
Precautions: To avoid plant injury, (1) Do not use on seedbeds or on unrooted cuttings. 
(2) Do not use in greenhouses or other enclosed areas.
Tank-Mix Partner Table 
Product Name EPA Registration 
Number
Active Ingredient(s)
AAtrex Various brands atrazine
Gramoxone 100-1431, 100-1652 paraquat
Rely 7969-448 glufosinate
Solicam 61842-41 norflurazon
Surflan Various brands oryzalin
STORAGE AND DISPOSAL
Do not contaminate water, food, or feed by storage or disposal.
Pesticide Storage
Store in a dry place.
Pesticide Disposal
Pesticide wastes may be toxic. Improper disposal of unused pesticide, spray mixture, 
or rinse water is a violation of Federal law. If these wastes cannot be used according to

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label instructions, contact your State Pesticide or Environmental Control Agency, or the 
Hazardous Waste representative at the nearest EPA Regional Office for guidance in 
proper disposal methods.
Container Handling
Container Handling [less than or equal to 50 pounds]
Non-refillable container. Do not reuse or refill this container. Triple rinse container (or 
equivalent) promptly after emptying. Triple rinse as follows: Empty the remaining 
contents into application equipment or a mix tank. Fill the container ¼ full with water 
and recap. Shake for 10 seconds. Pour rinsate into application equipment or a mix tank 
or store rinsate for later use or disposal. Drain for 10 seconds after the flow begins to 
drip. Repeat this procedure two more times. Then offer for recycling if available or 
puncture and dispose of in a sanitary landfill, or by incineration, or by other procedures 
approved by state and local authorities.
Container Handling [bags]
Non-refillable container. Do not reuse or refill this container. Completely empty bag 
into application equipment. Then offer for recycling if available or dispose of empty bag 
in a sanitary landfill, or by incineration, or by other procedures approved by state and 
local authorities.
Container Handling [fiber drums with liners]
Non-refillable container. Do not reuse or refill this container. Completely empty liner 
by shaking and tapping sides and bottom to loosen clinging particles. Empty residue 
into application equipment. Then offer for recycling if available or dispose of liner in a 
sanitary landfill, or by incineration, or by other procedures approved by state and local 
authorities. If drum is contaminated and cannot be reused, dispose of it in the manner 
required for its liner.
For minor spills, leaks, etc., follow all precautions indicated on this label and clean up 
immediately. Take special care to avoid contamination of equipment and facilities 
during cleanup procedures and disposal of wastes. In the event of a major spill, fire, or 
other emergency, call 1-800-888-8372, day or night.
CONTAINER IS NOT SAFE FOR FOOD, FEED, OR DRINKING WATER.

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AAtrex®, AAtrex® Nine-O®, Gramoxone®, Pennant Magnum®, Princep® Caliber 90®, 
and the Syngenta logo are trademarks of a Syngenta Group Company
Compex® trademark of KALO Agricultural Chemicals, Inc.
Rely® trademark of Bayer CropScience LP
Solicam® is a trademark of Tessenderlo Kerley, Inc.
Surflan® trademark of Dow AgroSciences
Unite® trademark of HACO, Inc.
Viton® is a trademark of The Chemours Company FC, LLC.
X-77® trademark of Loveland Industries, Inc.
For non-emergency (e.g., current product information), call
Syngenta Crop Protection at 1-800-334-9481.
©20XX Syngenta
Manufactured for:
Syngenta Crop Protection, LLC
P. O. Box 18300
Greensboro, North Carolina 27419-8300
PRINCEP CAL 90 603 MAS 1222 NOTIF.FEB2023-HI - di – 2/14/2023
000100.00603.20230215.PRINCEP_CAL_90.NOTIF.FEB2023-HI