by Peter Dotray – Extension Weed Specialist, Lubbock, TX; Scott Nolte – State Extension Weed Specialist, College Station, TX; Josh McGinty – Extension Agronomist, Corpus Christi, TX; Gaylon Morgan – State Extension Cotton Specialist, College Station, TX; Seth Byrd – Cotton Agronomist, Lubbock, TX
Auxin Certification Training has not been taken lightly across the state of Texas. Trainings started in January and to date have been a part of programs or has been the stand-alone topic at over 100 Texas locations. This training was mandated by the US Environmental Protection Agency (EPA) for all individuals who will be applying three newly formulated dicamba products because of the large number of off-target movement claims that occurred across several states in 2017. The three newly registered low-volatility dicamba herbicides are: XtendiMax® herbicide with VaporGrip® Technology (Monsanto, which received federal approval in November 2016), Engenia® Herbicide (BASF, approved December 2017), and DuPont® FeXapan® herbicide Plus VaporGrip® Technology (approved February 2017). In late 2017, EPA approved label revisions for these products, which are set to expire in November/December of 2018. Label renewals will depend largely on on-target application success in 2018. This training applies to all labeled uses of these herbicides. Enlist Duo™ and Enlist ONE™ are not a part of this required training, although the principles of on-target application can be applied to all herbicide applications. This training not only satisfies the federal requirement, but also satisfies the Texas Department of Agriculture requirement for auxin specific training. XtendiMax®, Engenia®, and FeXapan® were recently reclassified as Restricted Use Pesticides (RUPs). This training is not a substitute for the Certified Applicator training, and the purchase and use of RUPs can only be made by Certified Applicators or persons under their direct supervision. All individuals making an application of XtendiMax®, Engenia®, and FeXapan® in 2018 must complete the mandatory Auxin Certification Training. Highlights of the Auxin Certification Training are given below:
- Recordkeeping is required for all XtendiMax®, Engenia®, and FeXapan®
- The certified applicator must keep required records for a period of two years.
- Records must be generated as soon as practical but no later than 14 days after application.
- If 10 fields are sprayed, 10 sets of records are required, including if the same field is sprayed twice.
- Records must be made available to State Pesticide Control Official(s), USDA, and EPA upon request.
- Application record keeping forms may be found at: 1. https://ifca.com/files/Dicamba Recordkeeping Form-DEC 2017.pdf 2. https://www.engeniastewardship.com/…/Dicamba_record_keeping_form_12-15-17.pdf 3. http://www.dupont.com/content/dam/dupont/products-and-sservices/crop-protection/documents/en us/cp FX-9 FeXapan Application Record acro-v1.pdf
- Locate susceptible crops and sensitive areas around your dicamba tolerant crop field and develop an application plan.
- Adjacent susceptible plants. DO NOT APPLY when the wind is blowing toward adjacent susceptible crops, which includes non-dicamba tolerant cotton and soybean. Susceptible crops include but are not limited to tomatoes and other fruiting vegetables (EPA crop group 8), fruit trees, cucumber and melons (EPA crop group 9), grapes, beans, flowers, ornamentals, peas, potatoes, sunflower, tobacco, other broadleaf plants, and including plants in a greenhouse. Contact with foliage, green stems, or fruit of crops or any desirable plants that do not contain a dicamba tolerance gene or are not naturally tolerant to dicamba could result in severe injury or destruction.
- Sensitive areas. Maintain the required buffer to protect sensitive areas that may contain endangered species. The buffer zone IS NOT about managing drift to susceptible crops. The applicator must always maintain a downwind buffer between the last treated row and the nearest downwind field edge (in the direction the wind is blowing) for all uses of these products. Maintain an infield or out-of-field buffer (paved or gravel roads; fields prepared for planting; fields planted to corn, dicamba-tolerant cotton, sorghum, and small grains) of 110 feet (when applying 0.5 lb acid equivalent (ae) per acre) or 220 feet (when applying > 0.5 lb ae up to 1.0 lb ae per acre)
- Use only approved, low-volatility formulations of dicamba (XtendiMax®, Engenia®, and FeXapan®)
- Use only approved herbicides, other pesticides, and additives as tank-mix partners which have been found not to adversely affect off-target movement (OTM) potential. Approved tank mix partners can be found using the links below. Some tank mix partners require an approved drift reduction agent (DRA). Follow the recommended tank mix order for the DRA used. Tank mix partners can be found at
Applicators are required to consult specific product website no more than 7 days before application for a complete list of DRAs and other herbicides, pesticides, and additives approved for use with dicamba.
- DO NOT add ammonium sulfate (AMS) or other acidifying adjuvants to the tank when applying dicamba. AMS will increase the volatility of dicamba even in small amounts.
- Use approved nozzles within specified operating pressure range when applying dicamba. Approved nozzles are listed on the websites given above. Applicators are required to consult specific product website no more than 7 days before application for a complete list of approved nozzles.
- Apply when wind speeds are between 3 to 10 mph measured at the boom height.
- Do not exceed a ground speed of 15 mph. It is recommended that tractor speed is reduced to 5 miles per hour at field edges provided the applicator can maintain the required nozzle pressure for appropriate spray pattern.
- A minimum carrier volume of 15 gallons per acre (GPA) is required for XtendiMax® and FeXapan®, whereas a minimum of 10 GPA is required for Engenia®.
- Maximum boom height above the spray target is 24-inches. The potential for OTM increases substantially as boom height increases.
- Do not apply these products between sunset and sunrise because of concerns regarding temperature inversions leading to off-target movement.
- Do not apply these products during a temperature inversion. During a temperature inversion, the atmosphere is very stable and vertical air mixing is restricted, which can cause small, suspended droplets to remain in a concentrated cloud. The inversion will typically dissipate with increased winds (>3 mph) or at sunrise when the surface air begins to warm (~3°F from morning low). Inversions can be identified by the movement of smoke from a ground source or an aircraft smoke generator. Smoke that layers and moves laterally in a concentrated cloud (under low wind conditions) indicates an inversion. The potential for OTM can increase during a temperature inversion.
- Do not apply these products if rain is expected in the next 24 hours because of the possibility of runoff from applied areas to sensitive areas.
- Do not apply these products aerially!
- Spray system used to apply dicamba must be clean before using these products. One of the big concerns is contamination from AMS.
- Clean spray systems immediately after using dicamba. Refer to specific product labels for cleanout procedures. Do not allow the spray solution to remain in the system overnight prior to flushing. Failure to properly clean the entire system can result in inadvertent contamination of the spray system. Even very small quantities of dicamba may cause injury to susceptible crops. All rinse water must be disposed of in compliance with local, state, and federal guidelines.
If you have questions regarding the use of XtendiMax®, Engenia®, and FeXapan®, visit with any of the authors on this newsletter or with individuals of the manufacturers of these products. On-target applications must be a priority in 2018.