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Weeds

Photo Credit: Jamie Street - Unsplash.com (Cropped from original)
Description:

Weeds are considered the #1 pest in agroecosystems. They compete with desirable plants and can reduce yields, and alter soil structure and quality. Weed management requires thoughtful planning and action. Use the resources below to help reduce the effect of weeds in your crop, garden, or landscape.

2022 PNW Weed Management Handbook

By Ed Peachey

This comprehensive guide to weed management in the Pacific Northwest covers biological weed control agents; pesticide safety and disposal; agrichemicals and their properties; and control of problem weeds.

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Photo Credit: Jonne Huotari - Unsplash.com (Cropped from original)

Featured Resources

Malheur Experiment Station Virtual Field Tour - Controlling Glyphosate Resistant Weeds in Sugarbeets

Learn about an applied research project that is testing herbicides for the control of glyphosate resistant weeds in sugarbeets.

Christy Tanner, Joel Felix | Aug 2020 | Video Peer reviewed (Gray level)

Malheur Experiment Station Virtual Field Tour - Sonalan Tank Mixes for Weed Control in Potato

Learn about an applied research project evaluating tank mixes of the herbicide Sonalan for controlling weeds in potato.

Christy Tanner, Joel Felix | Aug 2020 | Video Peer reviewed (Gray level)

Onion Response to Talinor Herbicide - A Virtual Field Tour

A Malheur Experiment Station virtual field tour. Weed Scientist Joel Felix discusses a field trial evaluating the herbicide Talinor for use in onions.

Christy Tanner | Aug 2020 | Video Peer reviewed (Gray level)

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Having weed problems?

Solve Pest Problems is a partnership between OSU and Oregon stakeholders to provide a user-friendly online resource to help urban and rural property managers to solve pest problems. Learn research-based, safe, and effective tactics for common garden and property pests and weeds. We provide non-chemical methods alongside the most effective and least toxic chemical options available, to reduce risk to people and the environment.

Learn more

Common weeds

Pigweeds: Current and Emerging Weed Threats in the Pacific Northwest

Pigweed is an invasive plant pest usually found in disturbed areas, like farmland and along roadsides and fencelines. Because their aggressiveness can reduce crop yields, this PNW discusses how to prevent or curtail...

Albert Adjesiwor, Timothy S. Prather, Joel Felix | Nov 2021 | Extension Catalog publication Peer reviewed (Orange level)

Integrated Management of Prickly Lettuce in Wheat Production Systems

Prickly lettuce is a common weed in wheat production systems throughout the PNW, but it’s difficult to manage. Herbicides can control prickly lettuce in wheat, but many biotypes have developed resistance. An ...

Drew J. Lyon, Ian C. Burke | Feb 2021 | Extension Catalog publication Peer reviewed (Orange level)

Integrated Management of Downy Brome in Winter Wheat

Downy brome (Bromus tectorum L.), also known as cheatgrass, is especially troublesome in low precipitation production areas where crop rotations are mostly limited to winter wheat followed by a year of summer ...

Drew J. Lyon, Andy Hulting, Don W. Morishita, Frank Young | Aug 2020 | Extension Catalog publication Peer reviewed (Orange level)

Integrated Management of Feral Rye in Winter Wheat

Feral rye (Secale cereale L.), also known as volunteer rye, is a troublesome weed in winter wheat production in the low- and intermediate-rainfall zones of eastern Washington and Oregon and southern Idaho. This ...

Drew J. Lyon, Andy Hulting, Judit Barroso, Joan Campbell | Jun 2020 | Extension Catalog publication Peer reviewed (Orange level)

Puncturevine

A member of the Caltrop family, this weed produces woody fruits that always land with one sharp spine pointed upward. Spines injure hooves, feet, and vehicle tires. A toxin from the plant may be linked to ...

Robert (Bob) Parker, Rick Boydston | Apr 2020 | Extension Catalog publication Peer reviewed (Orange level)

More common weed guides

Best Management Practices for Managing Herbicide Resistance

By Drew J. Lyon Judit Barroso Joan Campbell Doug Finkelnburg and Ian C. Burke

Learn to manage herbicide-resistant weeds on your farm using the most effective methods, also known as best management practices (BMPs).

View publication
Photo Credit: Marcel Poncu - Adobe Stock (Cropped from original)

Latest Resources

Symptoms of herbicide damage

This photo-based, searchable database offers users the ability to filter by plant, mode-of-action, symptoms, and more. It also provides great written summary information on 13 of the most commonly-used herbicide groups. Homeowners can select from over 100 crop or ornamental plants and see photos of herbicide damage to help diagnose if a plant problem might be due to herbicide use.

Kassim Al-Khatib | Aug 2023 | Online resource

Which herbicides should I use on poison oak?

Q: I am dealing with poison oak growing in a stand of trees: Douglas firs, big-leaf maple saplings, and others. I have tried manual control and was unsuccessful. What would be the safest topical herbicide to apply to the leaves and stems while minimizing damage to the surrounding trees?

A: View answer | View all featured questions

Invasive Weeds in Forestland: Bull Thistle

Bull thistle is native to Europe, western Asia, and North Africa. It probably was introduced in eastern North America during colonial times, as a contaminant in seed or ship ballast. It is now the most ...

Stephen Fitzgerald | Apr 2023 | Extension Catalog publication Peer reviewed (Orange level)

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Latest News

Solve Pest and Weed Problems website gives gardeners solutions

The content – peer reviewed by the OSU Department of Horticulture – is presented in categories with information below each photo. Clicking on the photo takes users to another page that offers information about identification, ...

Mar 2023 | Impact story

Farm managers gain knowledge in OSU Extension’s virtual Coffee Hours

The Coffee Hour conversations attracted 37-61 people each week, including farmers who manage over 34,500 acres and agronomists who make crop management recommendations on over 209,000 acres.

Christy Tanner | May 2022 | Impact story

Controlling perennial bindweed takes persistence

This invasive perennial makes itself at home by sinking roots as much as 9 feet into the soil and can stay as an unwanted guest for up to 20 years.

Kym Pokorny | Apr 1, 2022 | News story

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Upcoming Events

Oct 7

Herb and Weed Walk at GrassRoots Garden

10:30 am - 12:30 pm Eugene, OR
See All Events

Meet Our Experts

Ed Peachey
(Retired)
Andy Hulting
(Former)
Judit Barroso
Weed Science
Cassie Bouska
Cassie Bouska
Agriculture

Contact with me with questions about agriculture in Coos and Curry counties

See All Weeds Experts
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Have a question? Ask Extension!

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Which herbicides should I use on poison oak?

Q: I am dealing with poison oak growing in a stand of trees: Douglas firs, big-leaf maple saplings, and others. I have tried manual control and was unsuccessful. What would be the safest topical herbicide to apply to the leaves and stems while minimizing damage to the surrounding trees?

A: View answer | View all featured questions

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