By Scout Nelson
As the harvest season ends, now is the best time for farmers to prepare a strong weed management plan for the 2026 growing season. Planning early helps reduce weed pressure, lower costs, and improve crop success.
One of the first steps is reviewing how weed management worked this year. Farmers should think about which strategies performed well, which tactics failed, and what factors influenced results. Herbicide choice, weed species present, crop rotation, soil type, and application timing all play major roles.
Weather also affects weed control, but it is something farmers cannot manage. Even if weed control was good, changing tactics helps prevent weeds from adapting.
Field-by-field planning is important because each field has unique soil, slopes, and weed types. Some fields may have had more weeds in 2025, especially areas flooded by heavy rain. These spots often become weedy and must be watched closely in 2026. Fields with late-emerging weeds or delayed herbicide applications should also be monitored with more care.
Farmers must also identify the weed species present. Wet conditions in 2025 allowed weeds such as barnyardgrass and smartweed to grow well and produce many seeds. Knowing which weeds are in each field helps guide herbicide choices for both preemergence and postemergence applications. Consult the most-recent South Dakota Pest Management Guides for a comprehensive list of herbicides labeled and species controlled.
Non-herbicide weed control is another useful tool. Tillage, narrow row spacing, stronger crop growth through good fertilizer use, mowing field edges, and hand-pulling small patches can all help reduce weed pressure. Using several methods together improves success and reduces the risk of herbicide-resistant weeds.
Crop rotation also supports weed control. Changing crops allows the use of different herbicides and breaks weed life cycles. Small grains and wheat can shade out weeds early and allow extra weed control after harvest. Perennial crops like alfalfa help control tough weeds through repeated cuttings.
However, some crops should be avoided in fields with hard-to-control weeds, such as planting conventional soybeans where kochia or waterhemp are strong problems.
Farmers should also evaluate herbicide failures. If failures are not caused by weather or misapplication, a new herbicide program should be used. If problems continue, fields should be checked for resistant weeds. SDSU Extension is currently working on surveying the state to determine the distribution of herbicide-resistant weeds Suspect Herbicide Resistance in Your Fields? SDSU Can lp!.
With early planning, diverse tactics, and field-by-field management, farmers can build a strong weed management plan for 2026.
Photo Credit: gettyimages-zoomtravels%201
Categories: South Dakota, Crops, Harvesting, Sustainable Agriculture