Dicamba - Frequently Asked Questions (FAQ)

Dicamba is a selective, systemic, and plant growth regulator herbicide primarily used for post emergence broadleaf weed control (for example, waterhemp, ragweed, horseweed) in a variety of crops, residential areas, and other sites. Dicamba herbicide belongs to Group 4 site-of-action.

Dicamba has long been used in agricultural and nonagricultural herbicide products. In Oct 2020, the United States Environmental Protection Agency (EPA) registered two end-use dicamba products XtendiMax® with VaporGrip® Technology (EPA Reg. No. 264-1210, Bayer), Engenia® (EPA Reg. No. 7969-472, BASF) until 2025 and extended the registration for dicamba product Tavium® Plus VaporGrip® Technology (EPA Reg. No. 100-1623, Syngenta) until 2025. These products are for applications to dicamba-tolerant soybeans and dicamba-tolerant cotton only.  

In Minnesota, waterhemp has evolved resistance to several herbicide classes (for example, glyphosate, ALS, PPO herbicides). Growers can use this technology in DT soybeans to control herbicide-resistant weeds such as waterhemp.

Dicamba is a highly volatile chemical that can damage non-target plant species through spray drift and/or volatilization (vapor drift). Dicamba products have the potential to cause serious damage to sensitive plants species such as non-dicamba-tolerant soybeans, grapes, trees, ornamentals, etc.

During the 2022 growing season, the MDA worked with the EPA and the registrants of the three dicamba products, XtendiMax®, Engenia®, and Tavium® to include the following restrictions on the product labels.

• Cutoff date:  Do not apply south of interstate 94 after June 12. Do not apply north of interstate 94 after June 30.
• Cutoff temperature for the entire state: Do not apply if the air temperature of the field at the time of application is over 85 degrees Fahrenheit or National Weather Service’s forecasted high temperature for the nearest available location for the day exceeds 85 degrees Fahrenheit. Forecasted temperature must be recorded at the start of the application.

The EPA has approved these restrictions and have amended the product labels for the three dicamba products listed above since 2022. These restrictions are valid until December 2025. The amended product labels with Minnesota-specific restrictions are also available on the product manufacturer’s website (Bayer, BASF, Syngenta). If the restrictions are not part of the container label, check the company’s website to download the restrictions prior to application of any of these three dicamba products. The restrictions are also promoted through the mandatory dicamba specific training, required for anyone applying one of the approved products, on the manufacturer’s website. Compliance with these Minnesota-specific restrictions and other restrictions listed on the product label is mandatory.

If you are planning to use one of the RUP dicamba products, you must attend auxin/dicamba mandatory training offered by dicamba registrants (Bayer, BASF, Syngenta). In addition, applicators must also follow the requirements of the Minnesota Pesticide Control Law. Other important control measures include:

• Requiring an approved pH-buffering agent (also called a Volatility Reduction Agent or VRA) to be tank mixed with the dicamba products prior to any over the top (post emergence) application.
• Requiring a 240 feet downwind buffer between the last treated row and the nearest downwind field/area edge.
• Tavium application is prohibited after V4 growth stage and XtenidMax application is prohibited after R1 growth stage.

Federal label requires, a 310 feet buffer downwind buffer between the last treated row and the nearest downwind field/area edge in areas where listed endangered species are located. In addition, a 57 ft buffer on all other sides of field must be maintained in areas with listed endangered species. The applicator must also follow the measures contained in the Endangered Species Protection Bulletin for the area in which applicator is applying the product. They must obtain Bulletins no more than six months before using the product.

It is a federal offense to use any pesticide in a manner that results in the death of an endangered species.

The MDA encourages reporting of any suspected pesticide damage. You can begin the formal complaint process by calling 651-201-6333 between 8:00 AM and 4:00 PM Monday through Friday or by submitting an online dicamba complaint form.

To submit a report of dicamba damage to the manufacturers use the following contact information:

• Bayer (XtendiMax) – 1-844-RRXTEND (779-8363)
• BASF (Engenia) – 1-800-832-HELP (4357)
• Syngenta (Tavium) – 1-866-Syngent(a) (866-796-4368)

During the 2022 growing season, the MDA worked with the EPA and the registrants of the three dicamba products, XtendiMax®, Engenia®, and Tavium® to include the following restrictions on the product labels.

DO NOT apply south of interstate 94 after June 12. DO NOT apply north of interstate 94 after June 30.

Statewide Restriction: DO NOT apply if the air temperature of the field at the time of application is over 85 degrees Fahrenheit or if the National Weather Service’s forecasted high temperature for the nearest available location for the day exceeds 85 degrees Fahrenheit. Forecasted temperature must be recorded at the start of the application.

The EPA has approved these restrictions and have amended the product labels for these three dicamba products since the 2022 growing season. These restrictions are valid until December 2025. The amended product labels with Minnesota-specific restrictions are available on the product manufacturer’s website (BASF, Bayer, Syngenta). If the restrictions are not part of the container label, check the company’s website to download the restrictions prior to application of any of these three dicamba products. The restrictions are also promoted through the mandatory dicamba specific training, required for anyone applying one of the approved products, on the manufacturer’s website.

Forecasted temperature for the site of application and the day of application must be recorded from the National Weather Service’s website.

No, Tavium label prohibits application after V4 stage of soybeans.

No, Tavium label prohibits application after V4 stage of soybeans.

You must follow the new amended labeling. The amended product labels with Minnesota-specific restrictions are available on the product manufacturer’s website (BASF, Bayer, Syngenta). Check the company’s website to download the restrictions prior to application of any of these three dicamba products. The restrictions are also promoted through the mandatory dicamba specific training, required for anyone applying one of the approved products, on the manufacturer’s website. Compliance with these Minnesota-specific restrictions and other restrictions listed on the product label is mandatory.

Each label for the new dicamba products specifies that applicators must attend training in order to use the dicamba products. Product manufacturers will provide training that meets the requirements of the label. Information about dicamba use and training is also available on the product label and product manufacturer’s website.

Manufacturers may provide record-keeping templates that includes the requirements of the label. Complying with each of these federal label requirements is mandatory.

MANDATORY dicamba or auxin-specific training is needed every year you plan to use the new dicamba products. Even if you received MANDATORY dicamba or auxin-specific training last year, you must complete it again this year and the next year to be able to legally purchase and use these three products this year and the following year.

No, dicamba or auxin-specific training is mandated only for those who use one of the new dicamba products.

No, a person only needs to attend one training session provided by any of the manufacturers of the new dicamba products, i.e. BASF, Syngenta, or Bayer. One annual training satisfies the training requirement for all three products.

Dicamba registrants (BASF, Syngenta, and Bayer) have prepared training materials and they, or their designees, will conduct training for dicamba applicators that meets the Minnesota specific label requirements.

The training takes approximately 1 hour.

The training will cover the product label requirements, recordkeeping requirements, weed management practices, buffer requirements and protection of sensitive crops, sensitive areas, and endangered species, spray drift management, chemistry, mixing and handling, window of application, equipment preparation and special considerations.

No, the class consists of instruction, review and open question-and-answer sessions.  Online training may have quiz components.

Once the training is completed, the applicator should obtain a certificate to keep.  This certification needs to be kept by the applicator with their application record(s) as a record. One of the recordkeeping elements for these registrations requires the certified applicator to show proof of completing dicamba-specific training.

The manufacturers will also be maintaining a record of those attending the class.  The MDA will be checking to ensure that applicators did attend the required training.

No, it will not be amended. Pesticide dealers are not required to see the proof of training to sell the dicamba products to certified applicators.

Information about training sessions can be found on product manufacturers’ websites (BASF, Bayer, Syngenta).

The MDA will recognize dicamba training that is based on material prepared by any of the three registrants (BASF, Syngenta, or Bayer) if the training is provided in Minnesota or a neighboring state (North Dakota, South Dakota, Iowa, or Wisconsin). The MDA has included additional Minnesota specific slides that applicators are expected to view.

Go to the EPA website or manufacturers website (BASF, Bayer, Syngenta) or contact the MDA.

Yes, the MDA accepts online dicamba training.

The product labels require applicators to check their webpages (BASF, Bayer, Syngenta) for any additional label restrictions or state specific requirements no more than 7 days prior to the application.

Non-sensitive crops and areas include paved or gravel surfaces; roads; mowed and/or managed areas adjacent to field, such as roadside rights-of-way; areas covered by the footprint of a building, silo, shade house, feed crib, or other manmade structure with walls and a roof; agricultural fields that have been prepared for planting; and planted agricultural fields containing asparagus, corn, dicamba-tolerant cotton, dicamba-tolerant soybeans, sorghum, proso millet, small grains, and sugarcane (the applicator is responsible for ensuring that the crops are dicamba-tolerant).

The applicator must always maintain a 240-feet downwind buffer between the last treated row and the nearest downwind field/area edge (in the direction the wind is blowing). Applicators can still use out-of-field non-sensitive crops and areas in the total buffer distance calculation. It should also be noted that the 240-feet downwind buffer is not intended to protect downwind sensitive crops and plants from off-target dicamba exposure. It is intended to protect other sensitive areas, for example, water bodies, non-residential areas, etc. The downwind dicamba application prohibition and the 240-feet downwind buffer requirement should not be confused when the concern is protection of downwind sensitive crops and plants.

A 310 ft downwind buffer plus 57 ft buffer on all other sides of field must be maintained in areas with listed species.

The applicator must follow the measures contained in the Endangered Species Protection Bulletin for the area in which applicator is applying the product. They must obtain Bulletins no more than six months before using the product. Applicators should consult the EPA Protecting Endangered Species from Pesticides or call 1-844-447-3813 to obtain the bulletin. The applicator must use the Bulletin valid for the month in which he will apply the product.

Applicators must follow the directions listed on the Endangered Species Protection Bulletin for protecting endangered species. The following areas may be included in the buffer distance composition when directly adjacent to the treated field edges:

1. Roads, paved or gravel surfaces, mowed grassy areas adjacent to field, and areas of bare ground from recent plowing or grading that are contiguous with the treated field.
2. Planted agricultural fields containing dicamba-resistant plantings of cotton and soybeans.
3. Areas covered by the footprint of a building, silo, or other man made structure with walls and or roof.

No, only dicamba-resistant plantings of cotton and soybeans can be a part of the buffer distances in areas with endangered species.

Sometimes yes, but often times buffers are required on several sides. Applicators should remember that buffers will often be required on two or more downwind sides of a target field if wind direction is not constant and non-target sites are not positioned completely perpendicular to one another. A 45-degree wind direction would require a buffer on two downwind sides. The applicator may have to change the buffer location with the change in wind direction during the application.

Yes, buffer distance can be reduced to 110 ft.

Yes, regardless of who owns the wooded lot, it is label-defined as a sensitive uncultivated area that may harbor a sensitive plant species or endangered species. Therefore, even an adjacent wooded lot that you own or control is required to have a downwind buffer.

No, dicamba application should not be made if the wind is blowing in the direction of sensitive crops.

Dicamba application can be made if wind is blowing in the direction of sensitive areas (e.g. water bodies, non-residential areas, etc.) and 240 feet downwind buffer requirement is followed.

No, dicamba application should not be made if the wind is blowing in the direction of sensitive crops.

No, downwind dicamba buffers would not be required next to these in-field areas. The EPA has concluded that grass waterways should be treated the same as Conservation Reserve Program (CRP) areas. Both CRP and grass waterways include voluntary conservation agricultural areas that could be used for cropland production. Therefore, buffers are not required to protect these voluntary conservation practice areas.

• Records must be generated within 72 hours after dicamba application and a record must be kept for every individual application.
• All commercial and noncommercial applicators must keep the required dicamba label records for a period of 5 years
• All private applicators must keep the required dicamba label records required for a period of 2 years
• Records must be made available to MDA, USDA, and EPA upon request.
• For all dicamba applicators, keeping records electronically is acceptable

In addition to the dicamba label recordkeeping requirements and to licensing requirements, Commercial and noncommercial applicators must meet record keeping requirements specified in the Law. For example, commercial applicators have to keep the applicator's company name and address AND the name and address of the customer, and rate of application. A noncommercial applicator record must have the applicator’s company name and address, and rate of application.

The MDA maintains samples of records on our web page that illustrate these requirements. Finally, Private Pesticide Applicators must meet the federally mandated record keeping requirements for Restricted Use Pesticides.

See a summary of applicator requirements.

The MDA encourages dicamba applicators to visit the National Weather Service website to see the timing of sunrise and sunset on that calendar day. Dicamba applications will be allowed only from 1 hour after sunrise to 2 hours before sunset.

New dicamba products are classified as Restricted Use Pesticides (RUPs) and can only be used by applicators that are either certified as Private Pesticide Applicators or licensed as either Commercial or Noncommercial Pesticide Applicators and certified in Categories A (Core) and C (Field Crops) as required by the Minnesota Pesticide Control Law. The Pesticide Control Law and federal label do not allow uncertified applicators to use the new dicamba products or any RUPs under the supervision of certified applicators.

Yes, the new dicamba products are classified as RUPs and as Agricultural Pesticides because of Worker Protection Standard language included on the product labeling and therefore require a pesticide dealer license. The MDA issues Agricultural Pesticide Dealer Licenses to businesses that offer for sale or sell agricultural pesticides to an end-user for use in the state of Minnesota.

Pesticide dealers selling dicamba must verify each end-user has either a valid Commercial, Noncommercial Pesticide Applicator License or a Private Pesticide Applicator Certification issued by the MDA.  Dealers must keep records of the purchase, sale, and distributions of these products for a period of five years. Additional requirements are detailed on the MDA Pesticide Dealer webpage.

Volatility and drift reducing agents are mandatory, and the applicator must provide proof of purchase to include with recordkeeping.

Buffers are required, the best way to demonstrate compliance is to draw a map as part of your application record showing where you left a buffer. In addition, buffers can be demonstrated through, GPS, picture, google earth.

You must have an anemometer in your possession at the time of the inspection to demonstrate that you had measured wind speed at the boom height.

Do not apply dicamba products when inversion conditions exist. There is more than one method such as smoke test and weather apps which can help to determine temperature inversion conditions in a field. The following are the indicators of presence of temperature inversion conditions:

• Calm day with wind speed less than 3 mph;
• Clear night;
• Dust cloud hanging on the side of the road;
• Dew or frost present on the ground;
• Horizontal smoke pattern; and
• Ground fog in low-lying area.
• If you farm in the central sands or NW Minnesota, MDA has collaborated with NDAWN to offer NDAWN Inversion Smart phone application the provides temperature inversion alerts based off of local ag weather stations. Inversion apps are merely a tool to identify temperature inversions. It is applicator’s responsibility to protect sensitive crops and areas from pesticide damage.

Applicators must document a sensitive crop registry was consulted prior to the application. Documentation must include the name of the sensitive crop registry and the date it was consulted. The Minnesota Department of Agriculture administers Fieldcheck for registering sensitive crops. For more information visit Fieldcheck.

Yes, dicamba products such as Clarity can be applied before planting DT soybeans. The product label for old dicamba products such as Clarity require at least 28 days rotational crop interval (days after application); and a minimum accumulation of 1 inch of rainfall or overhead irrigation must be observed following application.  These requirements may vary from product to product or there may be additional label requirements. For example, planting interval for Banvel is 60 days. Therefore, carefully read and follow all label requirements. This longer planting interval must be applied because DT soybean is not listed on Banvel, Clarity, DiFlexx, or other dicamba products.

For best control, post emergence dicamba applications should be made when broadleaf weeds are less than 4 inches in height. To manage broadleaf weeds, especially herbicide-resistant waterhemp (emerges throughout the growing season) after June 12th, the MDA recommends growers follow the University of Minnesota Extension recommendations on layering of residual herbicides such as Dual, Outlook, Warrant, and Valor. Incorporation of layering of residual herbicides in herbicide programs provide residual control of late emerging weeds. 

If you do not have herbicide-resistant waterhemp in a field, herbicides from these three sites-of action can be applied:

• Glyphosate (Group 9)
• ALS inhibitors such as Pursuit, Classic, FirstRate (Group 2)
• PPO inhibitors such as Flexstar, Cobra, Cadet, Ultra Blazer (Group 14)

Growers that have glyphosate-resistant waterhemp may consider using tank-mix of glyphosate with an herbicide from Group 2 or Group 14.

In other genetically engineered soybeans, for instance LibertyLink soybeans, applicators can use Liberty (Group 10) herbicide in addition to other labeled herbicides for weed management.

The MDA also highly encourages growers to use preemergence herbicides with residual control and to follow resistance management strategies, such as:

• Do not rely on a single herbicide site-of-action
• Apply full labeled rates
• Use preemergence herbicides with residual control
• Zero threshold for herbicide resistant weeds (for example: waterhemp) avoid application of herbicides with the same site-of-action more than twice in the season, incorporate non-chemical tactics (such as crop rotation, cover crops, weed free seeds) that are mentioned on the label as part of integrated weed management.