As dry conditions continue across many parts of the northern Plains and Pacific Northwest, farmers preparing to plant their spring wheat know grasses and broadleaf weeds will be waiting. Preparing a diversified weed management plan and implementing it early are two critical starting points for successful weed control all season.
Drought can complicate weed control efforts, especially when dealing with drought-tolerant weeds, like some perennial weeds, as well as more troublesome broadleaf weeds such as kochia, which can produce 30,000 seeds and reach seven feet in height with an extensive root system extending both downward and laterally. Other broadleaf weeds like chickweed and henbit and problematic grasses like green and yellow foxtail, cheatgrass and wild oats, must also be addressed with proactive control efforts.
“Under drought conditions, some weeds that would normally emerge earlier in the season and be controlled prior to planting, may not emerge until later, after the wheat has established a stand,” says Kevin Cochrane, retail account manager, Corteva Agriscience. “I encourage farmers to scout diligently and start their weed management program early to stay ahead of all broadleaf weeds and grasses that rob nutrients from wheat, limiting the plant’s resiliency and stealing yield potential. Our portfolio of premium herbicides helps farmers customize their weed control program, giving them crop flexibility and a broad range of application options.”
Farmers may, at times, feel like they are up against a seemingly stacked deck of weeds. In 2025, they will have a new high card in their hand to play with the addition of Tolvera™ herbicide. This new chemistry, recently announced by Corteva Agriscience, is a robust two-mode-of-action broadleaf and grass weed control product that includes a new active ingredient to the cereals market, tolpyralate (Group 27), as well as bromoxynil (Group 6).
“Tolvera herbicide will allow farmers to diversify and strengthen their herbicide resistance stewardship efforts away from reliance on ALS or auxin modes of action,” Cochrane says. “It will also help mitigate the spread of resistant weeds, while offering farmers flexibility through application options and a nine-month plant-back rotation to many important crops in the northern Plains and Pacific Northwest regions, including field peas, potatoes, sunflower and pulse crops.”
Until then, farmers can still rely on Quelex® herbicide, a time-tested stalwart herbicide that combines the active ingredient Arylex® active with florasulam. Quelex herbicide continues to be an invaluable tool to fight weeds and weed resistance.
“Quelex herbicide provides control of 28 broadleaf weeds, including marestail, mustards, mayweed chamomile and henbit,” Cochrane says. “It combines Group 2 and Group 4 active ingredients. It performs well in spring temperatures and makes a great tank-mix partner with Corteva herbicides.”
Another herbicide Cochrane sees more farmers using to strengthen any spring weed control program is Rezuvant® herbicide, which provides control of those early season weeds in both wheat and barley.
“Rezuvant herbicide includes three field-tested and proven active ingredients in one reliable postemergence herbicide solution,” Cochrane says. “It provides effective control on grass weeds like Italian ryegrass and foxtail, but also manages broadleaf weeds like common lambsquarters and kochia.”
Kochia and other broadleaf and grass weeds are prolific across the northern Plains and Pacific Northwest. Depending on weed population density, there are management options from which to choose, but control options should be implemented earlier rather than later.
“To manage weeds, farmers in these two regions often choose to ‘chem fallow’ fields. This weed control option involves making multiple herbicide applications over the year on fallow fields,” Cochrane says. “This method eliminates pulling iron across fields multiple times and helps limit soil erosion while conserving moisture.”
Another weed control option these regional farmers may use is to crop continuously. Many of them will chose to grow, for example, spring wheat, and then rotate to a pulse crop like peas, lentils or chickpeas.
“Cropping continuously allows them to diversify chemistries that target broadleaf weeds in cereal crops and grasses in pulse crops,” Cochrane says. “The use of multiple modes of action and switching application timings may also be done at burndown, preplant, pre- and postemergence, or postharvest to control weeds.”
As a dual mode of action herbicide (Group 27 + Group 5), Corteva’s new Tolvera™ herbicide technology can be a useful tool within a continuous cropping herbicide regime.
“I would encourage all farmers to learn more about Tolvera herbicide and be ready to add it to their cereal weed control programs in 2025,” Cochrane concludes.
Quelex®, Rezuvant® and Tolvera™ are not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Arylex® is a registered active ingredient. Always read and follow label directions.
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