Texas: Auxin Herbicides Required Training – What You’ll Learn In 2 Hours

Herbicide application. Photo: Debra L Ferguson

Herbicide application. Photo: Debra L Ferguson

In late October 2018, the United States Environmental Protection Agency (EPA) announced they will extend the registration of dicamba for two years (until December 20, 2020) for over-the-top (OTT) weed control in dicamba-tolerant cotton and soybean.



The extended labels include changes to ensure these products continue to be used effectively and to address concerns about off-target movement.

Initial label changes state that only certified applicators may apply dicamba OTT, prohibit OTT applications after 60 days after planting for cotton (45 days for soybean), limit the number of OTT applications to two for both cotton and soybean, allow applications one hour after sunrise to two hours before sunset, and in counties where endangered species exist, maintain the downwind 110 foot buffer and add a 57-foot buffer around the other sides of the target field.

Some of these new changes may be different before the 2019 growing season pending 24C requests that have been submitted to the Texas Department of Agriculture (TDA).  Upon approval, the 24c labels will be available on the Texas Department of Ag website.



Engenia herbicide (BASF Corporation), XtendiMax herbicide with VaporGrip Technology (Bayer CropScience), and DuPont FeXapan herbicide Plus VaporGrip Technology (Corteva Agriscience) are US EPA Restricted Use Pesticides (RUP) and State Limited Use (SLU) pesticides in Texas, which requires sale to and use only be certified applicators.  This training is not a substitute for the state-specified certified applicator training, which is required to purchase and use RUPs.

In addition to the EPA mandated dicamba applicator training, TDA has added 2,4-D Choline formulations (Enlist Duo and Enlist One) for use on 2,4-D tolerant crops to be included in these mandatory trainings.  These Enlist products are State Limited Use pesticides in Texas.  They can be sold to and used only by certified applicators or those working under the supervision of a certified applicator.

The two hour 2019 mandated Auxin Training will include the following topics:

  • why do auxin herbicides require additional precautions,
  • label requirements for approved auxin formulations,
  • understanding temperature inversions,
  • spray system hygiene,
  • record keeping, and
  • using dicamba and 2,4-D in a weed management system.


The Texas A&M AgriLife Extension Service will be providing a 2-hour in-person course, approved by TDA, that will fulfill the training requirements for Dicamba and 2,4-D Choline products and will include 2 hours of Laws and Regs.  Contact your county extension agent for training locations, dates, and times.

BASF Corporation, Bayer CropScience, and Corteva Agriscience also will be requesting TDA-approved training courses that will focus on their specific technology only and will therefore be 1-hour 1 CEU courses.