Dicamba Post Emergence Use in DT (Dicamba Tolerant) Soybeans

The MDA has kept the June 30th cut-off date for the use of three dicamba products, XtendiMax, Engenia, and Tavium on soybeans in Minnesota for the 2021 growing season (dicamba cutoff date announcement). The federal label prohibits applications of these three dicamba products after June 30th to dicamba-tolerant soybeans.  These formulations of dicamba are “Restricted Use Pesticides” for retail sale to and for use only by Certified Applicators and are the only approved products for dicamba tolerant soybeans .

Reference to commercial products or trade names here or elsewhere on this site is made with the understanding that no discrimination is intended and no endorsement is implied.

Questions are divided into the following categories:

  1. General Information
  2. 2021 Minnesota Specific Requirements
  3. 2021 Federal Requirements
  4. Dicamba or Auxin-specific Training
  5. Buffer Requirements for the Protection of Sensitive Areas and Endangered Species
  6. Record Keeping/Licensing
  7. Miscellaneous

 

General Information

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. Since dicamba was first registered for use on dicamba-tolerant soybeans in the 2017 growing season, the MDA has fielded complaints each year of alleged off-site movement onto neighboring property. The annual totals of complaints were: 2020: 124 reports, 2019: 22 reports, 2018: 53 reports, 2017: 253 reports.

New restrictions have been added on federal labels for dicamba use in 2021. All applicators will be retrained that they must read and follow all the label restrictions and requirements. 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.
  • Prohibiting over the top application of dicamba on soybeans after June 30 and certain crop growth stages. 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 away from 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)

2021 Minnesota Specific Requirements

No, there are no additional Minnesota specific restrictions for 2021 growing season. From 2018 to 2020, the MDA set June 20 as the annual cutoff date for registered dicamba products to curb off-site movement. This date was based on research and pesticide misuse complaints. At the time, there was not a cutoff date included on the federal label. In 2021, the EPA has included June 30 cutoff date on federal dicamba product label of XtendiMax, Engenia and Tavium. However, the EPA has now limited states’ abilities to impose further application restrictions.

While the EPA has limited states’ abilities to impose further application restrictions, the MDA has imposed additional conditions of registration for these products. As conditions of registration, the MDA requires 1. manufacturers to provide approved education and training of applicators and 2. to provide more Minnesota-specific data on the use of dicamba to inform department decisions in the future.

The EPA has limited states’ abilities to impose further application restrictions. From 2018 to 2020, the MDA used 24 (c) special local need (SLN) label for placing additional restrictions. EPA barred states from using the Section 24c special local needs label process to further restrict dicamba use.

No; the 2020 Minnesota-specific Section 24(c) label is no longer valid and cannot be used in 2021. The 2020 24(c) label expired on December 31, 2020.

No, tavium label is more restrictive than XtendiMax and Engenia labels and prohibits application after V4 stage of soybeans.

No, the federal label prohibits application after June 30 regardless of soybeans growth stage.

2021 Federal Label Requirements

Yes, several new federal label requirements were added for 2021. The additional requirements and restrictions included on the federal label for the new dicamba products in 2021 are:

  • Products are approved for use on DT soybeans only.
  • Federal label prohibits postemergence application of dicamba on soybeans after June 30th.
  • Approved pH-buffering adjuvant (also called a volatility reduction agent or VRA) is mandatory.
  • Copies of receipts for VRAs and DRAs are required for records.
  • A 240 feet downwind buffer between the last treated row and the nearest downwind field/area is required. A 310 feet downwind buffer is required in areas where listed endangered species are located.

Applicators must always read and follow all label directions. It is a violation of federal and state law to use any new dicamba product in a manner inconsistent with the label.

Federal label prohibits over-the-top application of dicamba on soybeans after June 30th for all three products. In addition, the federal label of Tavium prohibits application after June 30th or after V4 growth stage, whichever comes first for the target soybean crop. The federal labels for XtendiMax prohibits application after June 30th or after R1 growth stage. This means that these products cannot be applied once the R2 stage has initiated. R2 is a full bloom stage, when open flowers are present at one of the two uppermost nodes on the main stem with a fully developed leaf.

No, applicators must obtain and comply with the new 2021 federal label.  Applicators will need to obtain, comply with, and have in their possession at the time of application, the 2021 federal label. Visit the registrant’s website or contact the registrant for instructions on obtaining the new label.

Dicamba or Auxin-specific Training

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 label requirements for 2021 season.

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 (Bayer, BASF, Syngenta). 

Yes, the MDA has been accepting online training on of the dicamba products since January, 2021.

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). For 2021 training, the MDA has included a video presentation that applicators are expected to view.

Video: Dicamba post emergent weed control use on Dicamba Tolerant soybeans in 2021 (YouTube)

No, these dicamba products cannot be applied on crops other than DT soybeans.

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

Buffer Requirements for the Protection of Sensitive Areas and Endangered Species

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.

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.

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.

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-residentatial areas, etc.) and 240 feet downwind buffer requirement is follwed.

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

Record Keeping/Licensing

  • 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. A noncommercial applicator record must have the applicator’s company name and address.

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 windspeed at the boom height.

Miscellaneous

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.

FieldCheck is Minnesota’s sensitive crop registry, and it must be consulted per the label. Documentation must include the name of the sensitive crop registry and the date it was consulted. 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 30th, 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