General Information


DuPont WESTAR must be used only in accordance with instructions on the label, or in separately published DuPont instructions.

DuPont will not be responsible for losses or damages resulting from the use of this product in any manner not specifically instructed by the label. User assumes all risks associated with such non-labeled use.

Do not apply more than 6.0 ounces (0.375 pounds active) active ingredient sulfometuron methyl per acre per year when using this product or any other product containing sulfometuron methyl.

Do not apply more than 3.18 ounces active ingredient (0.199 pounds active) sulfometuron methyl per acre per single application to an Agricultural site when using this product alone or in combination with any other product containing sulfometuron methyl.

Do not apply more than 4.5 ounces active ingredient (0.281 pounds active) sulfometuron methyl per acre per single application to a Non-Agricultural site when using this product alone or in combination with any other product containing sulfometuron methyl.

WESTAR contains hexazinone. When applied alone or in combination with other products containing hexazinone: (1) For forestry use, do not apply more than 5 pounds of active ingredient per acre per year (2) For non-crop use, do not apply more than 8 pounds of active ingredient per acre per year.

Do not use on food or feed crops. 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.

The correct use rates by crop and geographical area, specified on the label, and proper mixing/loading site considerations and application procedures must be followed to minimize potential for hexazinone movement into ground water. Users are encouraged to consult with their state Department of Agriculture, Extension Service, or other pesticide lead agency for information regarding soil permeability, aquifer vulnerability, and best management practices for their area.


WESTAR herbicide is a dispersible granule that is mixed in water and applied as a spray. WESTAR may be used for weed control in terrestrial non-crop sites and for the control of certain weeds in conifers grown for forestry and Christmas tree production.

WESTAR is an effective herbicide providing both contact and residual control of many annual and perennial weeds. WESTAR can be tank mixed with other herbicides registered for use in forestry, Christmas tree and non-crop sites. Read and follow the Directions for Use for both products. WESTAR is non-corrosive to spray or mixing equipment, non-flammable and non-volatile.

Precaution must be exercised when applying WESTAR near desirable trees or shrubs as they can absorb WESTAR through roots extending into treated areas.

This product may be applied on forestry, Christmas tree and non-crop sites that contain areas of temporary surface water caused by collection of water between planting beds, in equipment ruts, or in other depressions created by management activities. It is permissable to treat intermittently flooded low lying areas, seasonally dry flood plains and transitional areas between upland and lowland sites when no water is present. It is also permissible to treat marshes, swamps and bogs after water has receded, as in seasonally dry flood deltas.

A drift control agent may be used at the manufacturer's listed rate in the application of WESTAR.


This product may be considered for use on public, private, and tribal lands to treat certain weed species infestations that have been determined to be invasive, consistent with the Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW) National Early Detection and Rapid Response (EDRR) System for invasive plants. Effective EDRR systems address invasions by eradicating the invader where possible, and controlling them when the invasive species is too established to be feasibly eradicated. Once an EDRR assessment has been completed and action is recommended, a Rapid Response needs to be taken to quickly contain, deny reproduction, and if possible eliminate the invader. Consult your appropriate state extension service, forest service, or regional multidisciplinary invasive species management coordination team to determine the appropriate Rapid Response provisions and allowed treatments in your area.


When herbicides that affect the same biological site of action are used repeatedly over several years to control the same weed species in the same field, naturally-occurring resistant biotypes may survive a correctly applied herbicide treatment, propagate, and become dominant in that field. Adequate control of these resistant weed biotypes cannot be expected. If weed control is unsatisfactory, it may be necessary to retreat the problem area using a product affecting a different site of action. To better manage herbicide resistance through delaying the proliferation and possible dominance of herbicide resistant weed biotypes, it may be necessary to change cultural practices within and between crop seasons such as using a combination of tillage, retreatment, tank-mix partners and/or sequential herbicide applications that have a different site of action. Weed escapes that are allowed to go to seed will promote the spread of resistant biotypes.

It is advisable to keep accurate records of pesticides applied to individual fields to help obtain information on the spread and dispersal of resistant biotypes. Consult your agricultural dealer, consultant, applicator, and/or appropriate state agricultural extension service representative for specific alternative cultural practices or herbicide recommendations available in your area.


This product may be used as part of an Integrated Pest Management (IPM) program that can include biological, cultural, and genetic practices aimed at preventing economic pest damage. IPM principles and practices include field scouting or other detection methods, correct target pest identification, population monitoring, and treating when target pest populations reach locally determined action thresholds. Consult your state cooperative extension service, professional consultants or other qualified authorities to determine appropriate action treatment threshold levels for treating specific pest/crop systems in your area.


- Site Specific Considerations

Understanding the risks associated with the application of DuPont WESTAR is essential to aid in preventing offsite injury to desirable vegetation and agricultural crops. The risk of off-site movement both during and after application may be affected by a number of site specific factors such as the nature, texture and stability of the soil, the intensity and direction of prevailing winds, vegetative cover, site slope, rainfall, drainage patterns, and other local physical and environmental conditions. A careful evaluation of the potential for off-site movement from the intended application site, including movement of treated soil by wind or water erosion, must be made prior to using WESTAR. This evaluation is particularly critical where desirable vegetation or crops are grown on neighboring land for which the use of WESTAR is not labeled. If prevailing local conditions may be expected to result in off-site movement and cause damage to neighboring desirable vegetation or agricultural crops, do not apply WESTAR.

Before applying WESTAR the user must read and understand all label directions, precautions and restrictions completely, including these requirements for a site specific evaluation. If you do not understand any of the instructions or precautions on the label, or are unable to make a site specific evaluation yourself, consult your local agricultural dealer, cooperative extension service, land managers, professional consultants, or other qualified authorities familiar with the area to be treated. If you still have questions regarding the need for site specific considerations, please call 1-888-6-DUPONT.

Limitations, Restrictions, and Exceptions



To help ensure safety to Grand Fir, use large transplant stock and apply DuPont WESTAR at 1.0 to 1.25 pounds per acre, or use after trees have been established for at least one growing season.

Western Red Cedar is very sensitive to WESTAR. If WESTAR is used on Western Red Cedar, severe injury may occur.

With no prior use experience, test a small area of plantings for conifer safety prior to treating larger areas, or make no application of WESTAR in these areas.

For conifer species not listed, either site preparation or conifer release treatments may be done if the user has prior experience with WESTAR.

In areas where other conifer species may be mixed in with the above listed conifer species, WESTAR may be applied if the user has prior experience with WESTAR on the other conifer specie(s). Apply by ground or helicopter only.


WESTAR applications made with backpack or boomless nozzle spray equipment may cause severe injury to conifers and/or poor weed control performance due to the inherent variability (rate and coverage) in the uniformity of application. Use 10 to 40 gallons of water per acre when applying WESTAR as a broadcast application. Be sure the sprayer is calibrated prior to use. Use a spray volume and delivery system that will ensure thorough weed coverage and a uniform spray pattern. Avoid overlapping the spray pattern and shut off spray boom when starting, turning, slowing, or stopping to avoid injury to desired species.


Use 5 to 15 gallons of water per acre when applying WESTAR. Be sure the sprayer is calibrated prior to use. Select a spray volume and delivery system that will ensure thorough weed coverage and a uniform spray pattern. Avoid overlapping the spray pattern and shut off spray boom when starting, turning or slowing to avoid injury to desired species.


Apply WESTAR preemergence or early postemergence (shortly after emergence) to herbaceous weeds (broadleaves and grasses).

Dormant trees are less susceptible to injury. Applications where the spray comes into direct contact with conifers after dormancy break in the spring or before the final resting bud has hardened in the fall may severely injure or kill the trees.


WESTAR controls or suppresses the following weeds when applied at 1 1/2 to 2 pounds per acre. When applied at the lower rate, WESTAR provides short-term control of the weeds listed below; when applied at the higher rates, weed control is extended. For best conifer safety on sites with varying soil types, make the rate selection based on the soil type with the coarsest texture -- low rate for coarse textured soils and the higher rates for fine textured soils.

Brackenfern: Controlled by postemergent applications.

St. Johnswort: Suppression - a visual reduction in plant population and/or plant vigor as compared to an untreated area and generally not accepted as control.



- The stress (loss of vigor) to conifers from insects, diseases, drought, winter damage, animal damage, excessive soil moisture, planting shock, previous agricultural practices, etc., may increase conifer sensitivity and the potential for injury from applications of WESTAR.

Conifer injury may also occur when WESTAR is used in conifers planted in gravelly or rocky soils.

- Do not use a surfactant in applications made over the tops of conifers. Using a surfactant with WESTAR and allowing the spray to contact conifer foliage may injure or kill the trees.

- When applying WESTAR after transplanting conifers, wait until rainfall has settled the soil around the base and root system of the seedlings before making the treatment.

Restricted Entry Interval

48 hours