With harvest wrapped up, now is a good time to consider how well you managed waterhemp in 2024 crop fields and make any needed adjustments for 2025. While no “new” solutions exist for waterhemp management, consider these points that may be “new” for your farm in 2025:

1. Change up your herbicides or rates. Many farmers rely on herbicide mixtures for their residual treatments. This tactic uses two or more herbicide groups to control a variety of weed species.

For 2025, consider whether the mixtures you’re using are working effectively. You may be better served by a different herbicide mixture for a spectrum of weeds in your fields.

Once you’ve settled on a desirable mixture, closely examine the rates of individual active ingredients. Many mixtures contain active ingredients at reduced rates.

For example, some corn herbicide mixtures containing acetochlor have only 50% to 60% of the full rate you would apply of the product by itself. Adding more of an active ingredient that carries the heaviest burden against waterhemp will control more plants and reduce the burden on postemergence herbicides.

2. Focus on timing. One of the largest challenges in weed management is choosing the optimal time to apply the postemergence herbicide. Ideally, an application would be before waterhemp plants reach 3 inches high. Unfortunately, this often means the application happens earlier than farmers would prefer, as the majority of waterhemp haven’t yet emerged.

Related:Why waterhemp is winning (so far)

3. Layer your residuals. Part of improving application timing of postemergence herbicides is including soil residual herbicides. Layering includes the application of a partial or full rate of a residual herbicide before crop emergence.

This is then followed by apply more residual herbicide postemergence to lengthen the time of control. Incorporating residual herbicides in timely postemergence applications let farmers stretch the weed control longer into the summer. This targets waterhemp’s late-emergence pattern.

4. Manage your fields differently. More than once, I’ve been asked about designing herbicide programs that enable spraying through waterways or spraying on both corn and soybeans. These tactics enhance simplicity for the applicators. Simple is great for us, but it is also great for weeds.

We are attempting to manage many factors at sub-field or even sub-acre level today. Why not consider managing weeds the same way?

Think about the weed pressure in different fields. Perhaps different pressures warrant different herbicide active ingredients, increased rates, or even a special extra pass with the sprayer.

Related:Check for ‘green carpet’ under harvested crops

This approach also may be beneficial within individual fields. If your fields have suffered from heavy weed pressure on field edges, consider managing for those edge areas. 2024 also had no shortage of drowned-out spots in crop fields. This often led to heavier weed pressure that will increase issues in those areas for the coming season.

5. Include tactics other than herbicides. It is no coincidence that the first four steps contained details on how to better manage herbicides, as they aren’t going anywhere. Herbicides will remain the primary line of defense against waterhemp and other weeds.

For herbicides to remain effective, though, we have to suppress weeds using other tactics and reduce — or ideally, prevent — weed seed entering the soil each year. While there is no one-size-fits-all solution, we have many nonchemical options to help manage waterhemp that include:

Stacking one or more of these with a robust herbicide program will improve long-term weed control.

Plan now for weeds

Now is the time to evaluate changes for your 2025 weed management strategy. While improving herbicide programs is the simplest thing to modify, the sooner we incorporate strategies such as field-specific management and nonchemical strategies, the better odds we have of beating waterhemp.

Related:Stop weeds while still seeds

Maybe 2025 is the year you try something different on a small field with big weed problems and see what happens. As always, don’t hesitate to reach out to your local Extension field agronomist for assistance in planning for next year.