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Time to consider weed control in sorghum

Sorghum Focus: New technologies offer options for postemergence grass control.

John Duff

May 7, 2024

2 Min Read
sorghum field
GRASSY WEED CONTROL: In the past five years, technologies have been introduced in sorghum that can help farmers control grassy weeds more effectively.Jennifer M. Latzke

It’s hard to believe #Plant24 is almost upon us on the High Plains and already over for many of my Southern readers. If the drought monitor is to be believed, those with a crop already up and growing along the Gulf Coast are in good shape, while things are still looking rough for parts of the High Plains. Despite this fact, the wheat looks good in many areas of the sorghum belt, which makes me think moisture is adequate to get the U.S. sorghum crop off to a decent start.

With that fact in mind, it’s time for farmers who haven’t planted to be thinking about weed control. Tackling the issue in sorghum, particularly with preemergence strategies, is crucial. The emergence of technologies such as igrowth, Double Team and Inzen has provided sorghum farmers with effective tools for postemergence grass control. However, the battle against broadleaf weeds, compounded by the rise of resistant species, necessitates a proactive approach. It’s essential to deploy a mixture of active ingredients across various modes of action to maintain an edge over these weeds.

A cornerstone of this strategy involves a comprehensive approach, incorporating at least two active ingredients. This not only broadens the spectrum of weed control but also mitigates the risk of resistance development.

Popular choices among sorghum growers include atrazine, combined with a Group 15 herbicide, to leverage their complementary modes of action. Premixes such as Bicep II Magnum (atrazine + s-metolachlor) and Fultime NXT (atrazine + acetochlor) are favored for their efficacy. Fultime NXT, in particular, is noted for its lower atrazine content, making it a preferable option for those seeking to minimize their use of atrazine.

For those looking to avoid atrazine altogether, alternatives like Verdict + Outlook offer a viable solution. Verdict, containing saflufenacil and dimethenamid, coupled with additional dimethenamid (Outlook), enhances residual control and is especially suited for sandy soils where atrazine can cause crop injury. Mesotrione, gaining popularity for its broadleaf weed control capabilities, should also be avoided in such soils, but in heavier soils can be effective in combination with atrazine or s-metolachlor, or as a part of a three-way mix.

Target: Grass control

The latest addition to the preemergence arsenal is imazamox, marketed as ImiFlex for exclusive use with igrowth sorghum. While it exhibits some broadleaf activity, ImiFlex primarily targets grass control, underscoring the importance of pairing it with a Group 15 herbicide.

As always, farmers should consult with their agronomist before making decisions on weed control and other strategies. With a well-informed approach to preemergence herbicide application and tool selection based on active ingredients, modes of action and soil compatibility, sorghum farmers can effectively manage weed pressures and ensure a healthy and productive 2024 for the U.S. sorghum industry. 

Duff is founder of Serō Ag Strategies and serves as a consultant to National Sorghum Producers. He can be reached by email at [email protected] or on Twitter @sorghumduff.

About the Author(s)

John Duff

John Duff is founder of Serō Ag Strategies and serves as a consultant to National Sorghum Producers.

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