General Information


SIMAZAT 4L is a herbicide that may be applied before weeds emerge or following removal of weed growth. It controls a wide variety of Annual broadleaf and Grass weeds when used at selective rates in agricultural and ornamental crops.

In each case where a range of rates is given, the lower rate should be used on Light soils and soils low in organic matter and the higher rates should be used on Heavy soils high in organic matter.

This product acts mainly through root absorption; its effectiveness depends on rainfall or irrigation to move it into the root zone. Should weeds develop, a shallow cultivation or rotary hoeing will generally result in better weed control.

This product is non-corrosive to equipment and non-flammable. Care must be taken to avoid using this product where adjacent desirable trees, shrubs or plants might be injured.


SIMAZAT 4L is a Group 5 herbicides. Any weed population may contain or develop plants naturally resistant to this product and other Group 5 herbicides. Weed species with acquired resistance to Group 5 may eventually dominate the weed population if Group 5 herbicides are used repeatedly in the same field or in successive years as the primary method of control for targeted species. This may result in partial or total loss of control of those species by this product or other Group 5 herbicides.

To delay herbicide resistance, consider:

- Avoiding the consecutive use of this product or other target site of action Group 5 herbicides that have similar target site of action on the same insect/mite species.

- Using tank-mixtures or pre-mixes with herbicides from different target site of action Groups as long as the involved products are all registered for the same use and have different sites of action and are both effective at the tank-mix or pre-pack rate on the weed(s) of concern.

- Basing herbicide use on a comprehensive IPM program.

- Monitoring treated weed populations for loss of field efficacy.

- Contacting your local extension specialist, certified crop advisors and/or manufacturer for herbicide resistance management and/or integrated weed management recommendations for specific crops and resistant weed biotypes.


Ground Application: For the most uniform distribution of broadcast applications, use 80° flat fan type nozzles. For band applications, use flat even spray nozzles. Screens and strainers should be no finer than 50 mesh. Use a pump with capacity to: 1) provide sufficient hydraulic agitation during mixing and application to keep the material in suspension; and 2) maintain 35 to 40 psi operating pressure.

Use a minimum of 5 gallons of water per acre for pre-plant incorporated, pre-emergence and post- (without oil or surfactant) applications. Use a minimum of 10 gallons of water per acre for all post-emergence applications combined with surfactant.

Where the amount of water is not specified, apply this product in 20 to 40 gallons of water per acre.

Limitations, Restrictions, and Exceptions


Broadcast 8 pints of this product (2 lbs. Atrazine a.i. + 2 lbs. Simazine a.i.) per acre in 20 to 40 gallons of water for adequate coverage. Apply in Fall or early Spring while trees are dormant and before weed seedlings are more than 1.5 inches high. This application will also control most Annual broadleaf and grass weeds.


1. Do not graze treated areas.

2. Do not apply to seedbeds.

3. When tank-mixing or sequentially applying Atrazine and/or Simazine or products containing Atrazine and/or Simazine, the total pounds of Atrazine and/or Simazine applied must not exceed the specific maximum rate per calendar year as noted in the use directions.