Recent Changes in Atrazine Rules for Fall Use on Corn & Sorghum Stubble

Atrazine (Group 5 herbicide) has long been a reliable tool for post-harvest weed control in corn and grain sorghum stubble. However, new label and regulatory changes mean that fall use is no longer permitted in many situations.

What’s Changed

• 24(c) Label Non-Renewal: Kansas and several other states did not renew the special 24(c) labels that allowed fall applications on corn or sorghum stubble.

• Rotation Restrictions: Current labels only allow atrazine use in wheat-fallow-wheat, wheat-corn-fallow, or wheat-sorghum-fallow systems.

• EPA Mitigation Requirements: Proposed federal label updates include lower annual rates, limits on applications to saturated soils, and added runoff restrictions.

What It Means

If you’ve applied atrazine post-harvest on corn or sorghum stubble in past years, that practice may now be off-label. Check each product label carefully before using atrazine outside of approved wheat rotations.

Alternatives & Best Practices

• Consider residual herbicides from other groups; sulfentrazone, flumioxazin, pyroxasulfone, or S-metolachlor.

• Watch for carryover or rotation restrictions.

• Apply under good soil and weather conditions, and document label compliance.

• Combine herbicides with cover crops or other integrated weed management practices.

Annual Use Limits

Total atrazine use must not exceed 2.5 lb active ingredient per acre per year (or 1.5 lb in some management zones). Always verify state-specific limits and buffer requirements.

Bottom line: Atrazine remains valuable, but fall applications on corn and sorghum stubble are now limited. Check labels, plan ahead, and stay compliant for a strong weed-control program.

Wishing you a happy holiday season! - Dwayne