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Posts Tagged: invasive weeds

New book helps pros manage invasive weeds in California forests

Scotch broom: A beautiful plant, but a forest nightmare.
Beautiful but unwelcome in California wildlands, brooms are shrubs introduced into North America from Europe in the mid-1800s. Common species include Scotch broom (Cytisus scoparius) and Portuguese broom (Cytisus striatus). Brooms were introduced as ornamentals, but also were used extensively for erosion control along roadsides and in mined areas.

Now growing profusely in California forests, on roadsides, and wildlands, brooms:

  • Crowd out out desirable vegetation
  • Form impenetrable thickets that limit access to some areas
  • Shade out tree seedlings, and make reforestation difficult
  • Burn readily, increasing the intensity of fire, and carry fire to the tree canopy
  • Are toxic to cattle and horses and unpalatable to most wildlife
  • Produce abundant, long-lived seed
  • Are able to fix atmospheric nitrogen, giving broom a competitive advantage over native plants

Management of these and other weeds are presented in the recently published second edition of Forest and Right-of-Way Pest Control. Invasive species that create a dangerous wildfire hazard and crowd out desirable vegetation and wildlife are examples of why this book emphasizes vegetation management and pesticide handling, including correct equipment calibration and effective herbicide application. The second edition also provides broader coverage of insects, plant pathogens, vertebrate pests, and the various practices to manage them, recognizing that lands commonly have multiple uses and when and how pests are managed depends on many considerations with sometimes conflicting goals.

Second edition of 'Forest and Right-of-Way Pest Control.'
One of many new features in this edition is a section with expectations and review questions, which will help professionals pass DPR's tough applicator certification examinations. The book may be used as a guide to safe and effective pest management on public and private forests, tree plantations and nurseries, and along roads, railways, utility corridors, biking and hiking trails, and other rights-of-way. Nearly 200 photos and illustrations, 56 tables and sidebars, and 11 main chapters aid in pest identification and problem diagnosis and provide users with pesticide and nonpesticide solutions.

Experts with Cal-Fire, Caltrans, PG&E, USDA Forest Service, private industry, the University of California (UC) Berkeley and Davis campuses, UC County Cooperative Extension offices, and the California Department of Pesticide Regulation (DPR) contributed to Forest and Right-of-Way Pest Control, prepared by UC ANR's Statewide Integrated Pest Management Program.

Forest and Right-of-Way Pest Control is available for $35 online in the UC ANR Catalog. The table of contents and more information about the book are available on the UC IPM website. You can also preview and electronically search the contents on Google Books.

Posted on Wednesday, March 5, 2014 at 8:46 AM

Unwelcome weed 'stinkwort' spreading quickly in California

Invasive weed stinkwort, Dittrichia graveolen, can spread rapidly on overgrazed land, river and stream banks and roadsides.
UC Cooperative Extension experts are advocating for aggressive control of invasive stinkwort to prevent it from becoming an established California weed, reported the Sacramento Bee. Joe DiTamaso, UCCE specialist in the Department of Plant Sciences at UC Davis, said he believes CalTrans will have to treat stinkwort as an invasive of high and unique concern if it has any hope of controlling its spread.

Stinkwort made its first California appearance in 1994, but remained quite rare until the mid-2000s, when it began spreading rapidly. Stinkwort is now found in 36 of the state's 58 counties, particularly along roadsides.

"If it gets a major foothold and produces millions and millions of seeds, then the seedlings will grow and they can form a carpet," DiTomaso said. "Then it would block light and prevent the growth of more desirable species – like native plants. It will out-compete them, and that is a concern."

Another troubling aspect is that the weed has been seen in vineyards, said John Roncoroni, UCCE advisor in Napa County, a weed science expert.

"I've seen it on the roadsides in Napa, and it's just encroaching into the vineyards at Napa Valley College," he said.

Posted on Tuesday, August 13, 2013 at 12:03 PM

When Contemplating Biocontrol of Pests

Nick Mills
What are the important considerations when contemplating the biological control of pests?

That's one of the topics when the Northern California Entomology Society meets on Thursday, Nov. 1 from 9:15 a.m. to 3 p.m. in the Contra Costa Mosquito and Vector Control District, 155 Mason Circle, Concord.

The group, comprised of university faculty, researchers, pest abatement professionals, students and other interested persons, will gather at 9:15 a.m. for registration and coffee.

First on the agenda is Kipling “Kip” Will, associate professor in the Department of Environmental Science, Policy and Management (ESPM), UC Berkeley, who will discuss “The Transition from Classical Alpha Taxonomy to Beta Taxonomy of Insects” at 9:30 a.m.

Nick Mills, professor of insect population ecology at ESPM and curator of UC Berkeley’s Essig Museum of Entomology,  will cover “Important Considerations When Contemplating Biological Control of Pests” at 10:15 a.m. 

Speaking at 11 a.m. will be Carlos Argurto, Pestec Integrated Pest Management Provider, San Francisco,  on “Contra Costa County IPM Program, Including New DPR (Department of Pesticide Regulation) Regulations for Surface Water Protection in Outdoor Non-Agricultural Settings.”

A luncheon catered by Kinder’s Custom Meats will be served at noon for a cost of $20 per person. (Advance reservations must be made with Nor Cal Entomology Society treasurer Eric Mussen, Extension apiculturist with the UC Davis Department of Entomology, at or by calling (530) 752-047.)

The afternoon session will include research entomologist Patrick Moran of USDA’s Agricultural Research Service, Albany, speaking at 1:15 on “Using Insects to Control Invasive Weeds in California.” 

The last speaker of the day is Stephen Colbert of DuPont Crop Protection, Escalon. At 2 p.m., he will discuss “What’s Behind the Label?” Colbert is active in the California Weed Science Society, based in Salinas.

The society meets three times a year: the first Thursday of February at the California Department of Food and Agriculture (CDFA), Sacramento; the first Thursday of May in the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis; and the first Thursday of November in the Contra Costa Mosquito and Vector Control District conference room, Concord.

Membership is open to the public; dues are $10 year, said society president Robert “Bob” Case of Concord, retired deputy agricultural commissioner from the Contra Costa County Department of Agriculture.

If you're interested in joining, contact Mussen at 

Lady beetle, aka ladybug, prowling for aphids on a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)
Lady beetle, aka ladybug, prowling for aphids on a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)

Lady beetle, aka ladybug, prowling for aphids on a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)

Close-up of lady beetle, aka ladybug. (Photo by Kathy Keatley Garvey)
Close-up of lady beetle, aka ladybug. (Photo by Kathy Keatley Garvey)

Close-up of lady beetle, aka ladybug. (Photo by Kathy Keatley Garvey)

Posted on Friday, October 26, 2012 at 9:22 PM

Invasive weed threatens California rice

Winged primrose willow grows erect, unlike other waterprimroses, which grow prostrate on the ground.
Winged primrose willow, a weed native to South America, was found last fall in a few Butte County rice fields, alarming agriculture officials about its possible spread to Colusa and Glenn counties, said an article in the Colusa County Sun-Herald.

The weed is highly invasive, produces vast quantities of seeds and survives under a wide range of hydrological and climatic conditions.

"Farmers have to keep an eye out for this weed, and let us know if they think they have it," said Luis Espino, UC Cooperative Extension advisor in Colusa, Glenn and Yolo counties, a rice production expert.

Unlike other waterprimroses, the winged primrose willow can grow within flooded rice fields, which makes it even more problematic for local farmers if it should get established in this area, Espino said.


Posted on Friday, April 27, 2012 at 10:25 AM

UC farm advisor outlines problems posed by invasive species

Faber said kudzu (shown above) was introduced as a ground cover, and then took off in the southern U.S.
Invasive plants and insects are proliferating faster than ever, causing massive problems in the environment, UC Cooperative Extension farm advisor Ben Faber told farmers at the Ventura County Research Symposium yesterday, the Ventura County Star reported.

Faber said invasive species are being introduced at a rapid rate around the world, and are primarily spread by humans.

He differentiated between non-native plants that are beneficial, such as avocados and citrus, and invasive plants that have been accidentally introduced into an ecosystem where they run rampant.

"An invasive species is something out of place and out of control," he said.

Fresno State report confirms state’s farmers apply water efficiently
Fresno State press release

Claims that California farmers are wasteful and inefficient in managing their water supplies are inaccurate, according to a new report released by Fresno State's Center for Irrigation Technology.

The study is the culmination of a yearlong effort by irrigation experts to update the 1982 University of California Cooperative Extension report “Agricultural Water Conservation in California with Emphasis on the San Joaquin Valley” by David C. Davenport and Robert M. Hagan.

The new study concludes that the 1982 report correctly framed the potential for agricultural water-use efficiency, and many of its findings are still relevant 30 years later.

Posted on Thursday, November 17, 2011 at 8:55 AM
Tags: Ben Faber (1), invasive weeds (5), water (1)

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