Restrictions on POST Herbicide Applications in Corn

Corn staging vs. height and herbicide cutoff

The leaf collar method is the most commonly used way to determine the stage of your corn. The leaf collar method starts with the first rounded tip or “thumb” leaf and counts each leaf that has a fully developed collar. 

📸: BASF employee/Featuring a close-up shot of V2 corn.

Decoding the Stages: V2 to V7 Corn & What Herbicides You Can Use

Corn staging is important, particularly when making herbicide applications because labels restrict the timing of these applications. Examples of important stages for herbicide applications:

• Status^® Herbicide: START at V2 (4 inches), STOP after V8 (or > 36", whichever comes first).
• Armezon^® Herbicide, Armezon^® PRO Herbicide, and Zidua^® SC Herbicide: STOP after V8.
• Liberty^® Herbicide: STOP after V6.
• Surtain™ Herbicide: STOP after V3.

📸: BASF employee/Featuring a close-up shot of V4 corn.

Height Limits Have Limits: Why Corn Staging is More Reliable

Some herbicides set limits based only on corn height. Examples of this include atrazine (“before corn reaches 12 inches"), acetochlor-containing products (“Do not apply to corn more than 11 inches tall"), and Outlook herbicide ("before it is greater than 36 inches tall"). The challenge with only relying on corn height is that growing conditions can cause more variation in the height of corn, while the collar method is a more accurate indication of the actual maturity of the corn plant.

What stage is the corn at in the photo below?

📸: BASF employee/Featuring a close up shot of V7 corn.

Before mixing components, always conduct a compatibility jar test. Always consult respective product labels for specific mixing instructions. The most restrictive label applies.

Always read and follow label directions. Grow Smart, Status, Armezon, Zidua, and Liberty are registered trademarks of BASF. Surtain is a trademark of BASF. All other trademarks are the property of their respective owners and use of any such trademark does not imply any affiliation with or endorsement by its owner. © 2024 BASF Corporation. All rights reserved.