UC Weed Research & Information Center

Broomrape podcast interview

February 4, 2026

By Brad Hanson

Some of my weed science extension colleagues in the midwest have a podcast called War Against Weeds supported with funding from the North Central IPM Center. I was interviewed on the podcast a few years ago about herbicide resistant weeds in orchards. Earlier this week, they invited me back…

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American pondweed with emerged inflorescences. Submerged or floating-leaved aquatic plants with roots within the soil sediment.

UCCE Sutter-Yuba Advisors to Participate in Weed Management Area Project

January 30, 2026

By Whitney B Brim-Deforest, Troy L Clark

UCCE Sutter–Yuba is pleased to announce the launch of a new collaborative project with the Sutter and Yuba County Agricultural Commissioners’ Offices focused on the identification and management of invasive weed species in the region. As part of this effort, this project will be coordinating ongoing mapping…

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Fig. 6. Adoption of herbicide spot application (A) and herbicide spray line outside the mulch line/tree rows (B) in a conventional walnut orchard site where walnut leaf mulch was implemented for weed management.

Response of Walnut Leaf Mulch for Weed Management

September 22, 2025

By Clebson G Goncalves

The use of walnut leaf biomass as a natural mulch and an eco-friendly practice can help prevent weed seed germination by excluding light and/or acting as a physical barrier that prevents weed emergence. Beyond that, several studies have shown potential allelopathic effects of juglone and…

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What pre-emergent activity does rimsulfuron have on established johnsongrass?

September 17, 2025

By Ryan Hill

To provide better recommendations on how to best use rimsulfuron and other residual herbicides to target johnsongrass I established a set of trials in Shasta and Tehama county prune and walnut orchards in winter and spring of 2025. I had two primary goals: first, to test if early spring rimsulfuron…

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Brad Hanson lecturing at Weed Science School 2023

Weed Science School 2025

September 4, 2025

Weed Science School is less than two weeks away! Join the UC Davis Weed Research and Information Center for this 2.5 day course. Learn through lectures and laboratory demonstrations at the Bowley Plant Science Teaching Facility at 1200 Extension Center Drive in Davis, CA on September 16-18, 2025.Weed…

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DPR’s New 2025 License Renewal and CE Verification Process

August 29, 2025

By Chris J McDonald

It’s that time of the year to start preparing for license and certificate renewal season for pesticide applicators with the California Department of Pesticide Regulation (DPR). Applicators should have received their renewal notice in the mail (and if not, then please contact DPR at LicenseMail@cdpr.ca.gov)…

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DPR License Category D, where Agriculture is also not Agriculture and is Wildlands too

August 19, 2025

By Chris J McDonald

In California, the Department of Pesticide Regulation (DPR) has a license and certification system which allows for professionals to apply pesticides as a part of their job duties. While everyone using pesticides must follow all directions on the pesticide label, as well as any additional state or local…

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picture of Fennimore retirement June 2025

UCCE Weed Specialist Steve Fennimore retires

July 31, 2025

By Brad Hanson

Sharing a link to an article posted by the UC Davis Department of Plant Sciences recapping the 28 year career of Cooperative Extension Weed Scientist Dr. Steve Fennimore.Here's a directly link to that article: https://www.plantsciences.ucdavis.edu/news/fennimore-retirement As a colleague of Steve…

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Branched broomrape hand weeding and heat treatment

July 21, 2025

By Brad Hanson

Branched broomrape hand weeding and heat treatmentPershang Hosseini, Magdalene Burgess, Rohith Vulchi, Ni Tang, Brad Hanson (UC Davis) IntroductionBranched broomrape (Phelipanche ramosa) is an obligate root parasitic weed that can affect a wide range of crops, most notably processing tomato in…

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CWSS Research Update (July 2025)

July 17, 2025

By Brad Hanson

The California Weed Science Society (CWSS) publishes a twice-yearly "CWSS Research Update and News" newsletter as one of the society's publications. The July 2025 issue just went online and is available here: https://cwss.org/wp-content/uploads/2025/07/CWSS_Research_Update-July-2025.pdf This issue…

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Meet our New Agronomy Advisor, Mandeep Singh

July 10, 2025

By Mandeep Singh

My name is Mandeep Singh, and I’m honored to serve as the Agronomy Advisor for Sacramento, Solano, and Yolo counties, based at the UCCE Capitol Corridor office in Woodland. From an early age, I was involved in managing row crops like alfalfa, wheat, cotton, rice, sorghum, and oats, as well as caring for…

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Branched broomrape in a tomato field near Santiago, Chile.

Chemigation Alternatives for Branched Broomrape Control in Processing Tomato: Promising Steps Forward

July 8, 2025

By Matthew Fatino, Brad Hanson

Branched broomrape (Phelipanche ramosa) is an invasive parasitic plant that poses a significant threat to California’s processing tomato industry. Known for its ability to attach to and draw nutrients from host roots, this pest can cause yield losses and trigger strict quarantine measures in California…

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Tomato field with colored flags marking emerged branched broomrape clusters.

Sequential applications of chemigated rimsulfuron reduce broomrape emergence in California tomatoes.

June 9, 2025

By Matthew Fatino, Brad Hanson

Branched broomrape (Phelipanche ramosa) continues to challenge California’s processing tomato industry, particularly in the Sacramento Valley. As a parasitic plant that attaches to tomato roots, its presence threatens both yield and export market access. In a recently published study in Weed Technology, we…

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Survey on Weed Control Technologies for Tree and Vine Crops

May 6, 2025

By Brad Hanson

Note: I'm sharing a survey request related to grower and industry needs related to novel weed control technologies in orchards, vineyards, and other perennial specialty crops. Our team of research collaborators is developing this information as a first step towards a future coordinated national…

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Four men in weedy area. One is holding a measuring container while another sprays liquid into it from a wand attached to a backpack sprayer. A third person holds a clipboard and the furth holds a stopwatch.

New Online Course: Calibrating Herbicide Applications for Non-Agricultural Areas

April 14, 2025

By Cheryl A Reynolds

Calibration might sound intimidating, but it’s critical for safe and effective herbicide application. Proper calibration ensures that the correct amount of pesticide is applied to an area while achieving the desired level of pest control. To support land managers and pesticide applicators, the UC Statewide…

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Late Rains, Small Plants, Fast Phenology

April 4, 2025

By Chris J McDonald

Originally Posted April 1, 2025. This year in Southern California the rainy season got off to a late start. Southern California has received about one half of the average precipitation total as of this writing (and that's not an April fool's joke). Last year we had over 50% more rainfall than the…

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webinar video on electric weed control in organic perennial crops

April 2, 2025

By Brad Hanson

A quick repost to share a link to a recent January 14, 2025 webinar on Electric Weed Control in Organic Perennial Crops. The webinar was part of a multi-state research and extension project that includes researchers from Oregon State University, Cornell University, and UC Davis and outreach support from…

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WeedCut: BMPs for herbicide application techniques

April 2, 2025

By Brad Hanson

Sharing a recent post from the California Invasive Plant Council (Cal-IPC) about a new page on the WeedCUT online decision support tool. -Brad--------------------------------------------------------------------New WeedCUT Feature: BMPs for Herbicide Application Techniques Confused about…

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webinar video on electric weed control in organic perennial crops

January 17, 2025

By Brad Hanson

A quick post on a Friday afternoon to share a link to a recent (January 14, 2025) webinar on Electric Weed Control in Organic Perennial Crops.

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Best Practices for Using Glufosinate in Hops

January 16, 2025

By Brad Hanson

Reposted from the "Weeders of the West" blog with author's permission. Marcelo Moretti summary of research on glufosinate best practices in hops (direct link to article). -Brad Posted by jenna.osiensky | January 9, 2025 Marcelo L.

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Welcome to the Weed RIC

Please visit the main

UC Weed Research and Information Center
website at: https://wric.ucdavis.edu

The UC Weed Research and Information Center (Weed RIC) is an interdisciplinary collaboration that fosters research in weed management and facilitates distribution of associated knowledge for the benefit of agriculture and for the preservation of natural resources.

Employment opportunities

Ecological Pest Management Program Specialist
Company: Community Alliance with Family Farmers (CAFF)
Location: Davis, CA
Date Posted: 12/1/2020
Closing Date: 12/5/2020

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