Wisconsin Manual of Control Recommendations: Ecologically Invasive Plants

Herbicides

General Herbicide Information

The Wisconsin Department of Natural Resources does not endorse any particular herbicide or manufacturer, and therefore trade names are not used in the control recommendations. The chemicals mentioned in the text are listed in the information table. Examples of trade names associated with each chemical are provided in the table, although other products with similar formulations may be available. Mixture percentages listed in the manual refer to percentage of active ingredient, not percentage of herbicide straight from the bottle. Calculate the required mixture based on the percentage of active ingredient listed on the label.

Some herbicides come in amine and ester formulations. Amine formulations are less volatile (likely to vaporize and drift) than ester formulations. As ester compounds generally have a higher volatility, they should be used only with extreme caution in warmer weather months to avoid damaging non-target plants or endangering other humans. Esters are best used during the late fall, winter, or very early spring (before buds break) when temperatures are cool. Esters used at this time are more effective than amines, as they are more readily absorbed by plant tissue.

By law, herbicides must always be applied according to label instructions. In some instances, recommendations in this manual suggest a concentration lower than that recommended on product labeling. It is legal to dilute herbicides with an appropriate dilutant--refer to the label.

General Application Procedures

Foliar spot applications of herbicide should be done uniformly with a hand sprayer, sponge applicator, or wick to ensure that the entire leaf is wetted. Do not spray so heavily that herbicide drips off the target species. Spray application will usually involve mixing a surfactant/dispersal agent with the herbicide--follow label directions. Colorants or marker dyes may also be added to assist in proper herbicide application--again, follow label instructions.

When applying herbicide to cut stumps, apply soon after cutting. Trees and shrubs should generally be cut at the end of the growing season so that chemicals will be actively absorbed into the stump, although many species may be treated in the winter--follow specific suggestions for individual species. Basal bark application should encircle the trunk within 6-12" of the base, and normally consists of a band of herbicide approximately 6" wide.

Herbicide Licensing and Certification

Pesticides are categorized as either Restricted-Use or General-Use, and may be differentiated by labeling on the container. Wisconsin state certification and licensing requirements differ depending on the status of the applicator. Any individual who purchases, mixes, loads, applies, disposes, or directs the use of a Restricted-Use pesticide must be certified and licensed.

Any person involved in the application of pesticides to land other than their own is by law considered a Commercial Applicator. An individual applying pesticides for a customer who is charged for the application is considered a Commercial Applicator For Hire. Commercial Applicators For Hire must be certified and licensed for both Restricted-Use and General-Use pesticides.

An individual applying pesticides to land controlled by that individual or his/her employer and not receiving compensation beyond normal wages is considered a Commercial Applicator Not-For-Hire. This category includes almost all employees of governmental or educational institutions, and individuals volunteering for non-profit organizations and government agencies . Commercial applicators not-for-hire must be certified and licensed for Restricted-Use pesticides that are applied. Although commercial applicators not-for-hire may apply General-Use pesticides without certification and licensing, the Wisconsin Department of Extension strongly encourages certification for anyone who uses pesticides. In this case, licensing would not be necessary.

For more information on pesticide certification and licensing, contact:

Herbicide Use Procedures

Transportation and Storage:

1. Herbicide concentrations must be stored in their original container in good condition, with an attached legible label, preferably in locked storage.
   
2. Do not store herbicides with food, feed, or personal protective equipment. Transport secured containers outside the passenger compartment of a vehicle.
   
3. Always carry spill response equipment in the event of an accidental spill during transportation or use.

Mixing and Loading Pesticides:

1. Before using any pesticide, READ THE ENTIRE LABEL FIRST!! The label is a legal document which you must read and obey. The pesticide label provides important information such as: Precautionary Statements, Directions For Use, and Environmental Hazards.
   
2. When mixing or loading herbicides you are required to wear protective clothing to reduce your risk of exposure. Read the label of the herbicide(s) you are mixing for the Personal Protective Equipment (PPE) required. The following PPE is required for mixing all concentrate pesticides in addition to any other PPE listed on the label: (long pants, long-sleeved shirt, goggles, rubber or neoprene boots and gloves, and either a chemical-resistant apron, coveralls, or rainsuit.)
   
3. Keep drinking water, decontamination water, and rinsate & mixing water in separate containers.
   
4. Mix and load on an impermeable surface such as concrete or blacktop, or by placing the application equipment into a chemical-resistant tub or basin for containment. Do not mix within 100 feet of a well, storm drain, or surface water. Should a spill occur, recover it immediately and report it to the appropriate spill response agency. In Wisconsin, the Emergency Response Number for pesticide incidents is answered by the DNR. SPILL HOTLINE: (800) 943-0003

Pesticide Applications and PPE:

1. Use appropriate PPE--READ THE LABEL!
   
2. Wash your hands frequently during pesticide applications. Always wash your hands before eating or smoking. Avoid touching your bare skin with contaminated equipment or PPE.
   
3. Try to use all of the herbicide solution that you mix. Storage of mixed solutions can reduce the effectiveness of some herbicides. If you must store mixed solutions, use within a few days, storing in an appropriate container labeled with the common name, concentration, EPA registration number, and the words, "DILUTE PESTICIDE SOLUTION."

Equipment Clean-up:

1. All empty pesticide concentrate containers must be triple-rinsed, using 10% of the container volume for each rinse. Empty the container completely, and puncture to prevent other use. The rinsate should be used in future mixes. Unless it is stated on the label or requested by your waste disposal contractor, "empty, triple-rinsed, clean pesticide containers" can be disposed of through normal waste disposal channels in sanitary landfills. Pesticide containers cannot be recycled unless it is through an agrochemical container recycle program.
   
2. At the end of the day, all PPE should be washed with mild soap and water. This water can be used with future mixes or sprayed through equipment as a rinse treatment.
   
3. Shower and change into clean clothing as soon as possible following application duties. Do not wear application clothing again without washing it first.
   
4. If concentrate is spilled on your clothing, discard the items. Wash pesticide application clothing separate from other laundry.

Herbicide Information Table

This table provides information on chemicals listed in the control recommendations. Chemical names are used in the recommendations. The percentage of active ingredient in each of these brands is variable; information in the recommendations provides percentages of active ingredient required for effective treatment. "Application" refers to those species which the herbicide affects. Non-selective herbicides will kill any plant with which it comes into contact.

¹ Mention of trade names and commercial products does not constitue endorsement of their use.