Be Proactive to Manage Weeds in Cereals

Wild Oat in a cereal field

Wild oats infest a cereal crop. This and other prolific weed species known to infest cereals should be approached with a zero-tolerance standard to weed control.

With the aggressive spread of herbicide-resistant weeds across the United States, weed scientists recommend an integrated approach to weed management. A weed control strategy for winter and spring wheat, plus other cereal crops such as barley, begins with a proactive plan that uses multiple best management practices (BMPs) to effectively control tough-to-manage and resistant weeds.

Take every measure possible to keep fields weed-free. When weeds are allowed to go to seed and enter the soil seedbank, they can cause problems years down the road. For cereals growers, be especially aware of weed and grass species such as kochia, Russian thistle, prickly lettuce, downy brome, barnyard grass, wild oats and foxtail.

Growers should start and finish with a clean field. Upon germination, weeds compete with your crop and rob sunlight, soil, water and nutrients that are critical for good stand establishment. In Nebraska alone, it’s estimated that broadleaf weeds account for a 10 percent yield reduction in winter wheat annually. When wheat is priced at $6 per bushel, that’s a $35 million loss per year for Nebraska wheat growers.

In addition, when a grower runs a planter through a weedy field, the weeds often become damaged and more difficult to manage if subsequent herbicide applications are needed. Without effective control, weeds can lead to combine damage, slow harvest and price dockage at the elevator because of weed seeds and increased grain moisture.

When choosing herbicides to control problem weeds in fields, take resistance management into consideration. For over two decades, common weeds in wheat have been resistant to ALS herbicides frequently used in wheat. Weed resistance to other chemistries such as glyphosate, PPO, ACCase and HPPD continues to spread, along with other problem weeds such as pigweeds, winter annual mustards, kochia and marestail in wheat and other crops.

To control tough-to-manage and resistant weeds, growers should tankmix herbicides with multiple sites of action in the tank to prevent selection for resistant weed biotypes. Growers have been able to control most resistant weeds by adding different sites of action with ALS and protect the value of the chemistry. Use the same practices to protect newer chemistries as well. Rotating sites of action should be a standard practice for all farmers.

When choosing a pre-emergence herbicide, consider the following:

  • Labeled length of residual
  • Application timing
  • Weed control spectrum
  • Resistance management
  • Crop rotation flexibility

Dr. Richard Zollinger, North Dakota State University Extension weed specialist, describes additional weed management considerations and how much impact weeds can have on wheat yields when left uncontrolled. He provides the following statistics:

  • Wheat yields can be reduced by 10 to 20 bushels per acre or 35 percent when 10 wild mustard or wild oat plants per square foot infest a wheat field.
  • Wheat yields can be reduced by 30 percent with two to three kochia plants per square foot.
  • Yields may be reduced by 60 percent when Canada thistle patches infest a field.
  • If late planting occurs, wheat yields can be reduced 10 to 15 percent by green foxtail infestations.

Experts agree a system approach to weed control should include fall or early spring applications, burndown, tank mixes and the treatment of weeds when they are small. In today’s environment, there’s no such thing as an economic threshold for weeds. Zero tolerance for resistant seed in the soil bank should be the goal.

Bayer Solutions

Bayer offers a broad portfolio of herbicides to control tough-to-manage and resistant weeds in cereals. A well-thought-out herbicide program, using multiple sites of action and nonchemical practices, should be implemented.*

Spring Wheat

Huskie® Complete herbicide** (2, 27, 6) is an all-in-one wheat herbicide and is a combination of Huskie (6, 27) with ALS grass control and an HPPD-inhibitor chemistry. Together, these sites of action provide good control of green and yellow foxtail along with 50 grass and broadleaf weeds.

Growers can use Olympus® (2) wheat herbicide at burndown as a cost-effective, reliable solution to suppress brome grass in spring and winter wheat. With excellent crop tolerance, Olympus allows for pre-plant, pre-emergence and postemergence application in spring wheat crops.

Wolverine® Advanced (1, 6, 27) controls 69 grass and broadleaf weeds in wheat thanks to three sites of action in a single product. This wheat herbicide is an excellent tool to consider as a grass-chemistry rotation partner to manage weed resistance.

Varro®(2) controls grass weeds and provides excellent rotational flexibility and allows for a wide range of choices in broadleaf tankmix partners while enhancing the performance of these tankmixes.

Winter Wheat

Huskie® herbicide(6, 27) is available to wheat growers in 40 states and includes a unique product for cereals with multiple sites of action, which are responsible for controlling broadleaf weeds such as kochia, Russian thistleprickly lettuce and wild buckwheat – including ALS- and glyphosate-resistant biotypes.

Bayer also offers Olympus® wheat herbicide to help keep fields clean from start to finish with its residual activity to help fight weeds as they germinate. Growers can use Olympus at burndown as a cost-effective, reliable solution to suppress brome grass in spring and winter wheat.

Osprey®(2) herbicide offers broad-spectrum grass control in winter wheat. It provides full rotational crop flexibility and can be tankmixed with many broadleaf herbicides for one-pass weed control.

To learn more about using herbicides with effective sites of action, see the Herbicide Resistance Management Guide. View Bayer’s product portfolio to learn more about weed control from Bayer or contact your local Bayer representative.

* Not every product is suitable for every situation, nor registered in every state, and proper application techniques will enhance results. Before applying any herbicide, please read the entire label for the best possible results and to confirm that the product is effective on the weeds you wish to control.
** Huskie Complete is a Restricted Use Pesticide.
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