Making the Most Out of Late Burndown Applications

The calendar says it is about time to plant the 2019 crop, and many farmers are eager to get in the fields. But with excessive rains, late snowfall  and cooler-than-expected temperatures, it has been difficult to apply spring burndown in a timely manner. Unfortunately, weeds continue to grow, taking advantage of all the heat units produced to date, resulting in larger weeds that require maximum herbicide rates to obtain acceptable control.

While burndown applications are normally done up to 30 days preplant, burndown is being done today just a few days or hours in front of planting and crop emergence. Some farmers will even plant the crop first then apply burndown prior to emergence.

Here are a few things to keep in mind when it comes to late burndown applications and weed control:

  • In many cases, residual preplant herbicides are now being combined with burndown applications. Compatibility of intended tank mixes may become an issue. Be sure to study the label of preplant herbicide selected to see if the products you’re using are compatible.

  • The “days before planting” (DBP) and “days before emergence” vary widely between various products in corn and soybeans, so pay close attention. Final plant populations can be negatively affected if waiting periods are not met.

  • For Corn: When using 2,4D and/or dicamba in burndown, remember to adhere to 7 to 14 DBP restrictions. Increasing the herbicide rates to control larger target weeds may require a longer DBP.

  • For Soybeans: Avoid using dicamba on burndown unless dicamba tolerant soybeans are to be planted, then use only approved dicamba products for post-emergence use. Using any other dicamba product will delay planting a minimum of 14 days. The same restriction applies when requiring EnlistTM herbicides to be used with Enlist E3TM soybeans as a burndown product.

  • Products such as paraquat, glyphosate, glufosinate and saflufenacil can be applied as burndown with no DBP restrictions. Always read the herbicide label for rates needed and adjuvants required to control weed size present in the field.

  • In most cases the proper adjuvants should be used at the highest rates to ensure herbicides are entering the plant as required to terminate the weeds.

Read this next: Adjuvants 101: Understanding the “Extras” in Your Tank (4 min read)

PRO TIP: Coverage of spray mixture on target weeds in important to achieve acceptable weed control with all products. Increasing spray volume up to 20 gpa may aid in control of larger weeds in a burndown situation. Read the label to find optimum gallonage for the herbicide to be used.

ALWAYS READ AND FOLLOW LABEL USE INSTRUCTIONS. It is a violation of federal and state/provincial law to use any crop protection chemical or product other than in accordance with its label. The distribution, sale and use of an unregistered crop protection chemical or product is a violation of federal and/or state law and is strictly prohibited. It is your responsibility to confirm prior to purchase and use that a product is labeled for your specific purposes, including, but not limited to, your target crop or pest and its compatibility with other products in a tank mix.

Enlist™ and Enlist E3™ are trademarks of Corteva Agriscience or an affiliated company.