Mendocino County
University of California
Mendocino County

ANR Blogs

Summer weed control with glyphosate tank mixed with indaziflam or penoxsulam in California orchards and vineyards.

untreated panicle willowherb in a CA vineyard

Today I thought I would post a brief writeup and a poster presentation by Amit Jhala, a recent postdoctoral researcher in the UCD weed group.  Amit and I put out two small experiments in the spring of 2010 to evaluate combinations of glyphosate (Roundup...

2011 WSSA poster Jhala herbicide screen
2011 WSSA poster Jhala herbicide screen

Posted on Monday, February 21, 2011 at 9:56 PM

Study to examine giant sequoia groves

The giant sequoias of the Sierra Nevada are the biggest and among the oldest trees on the planet. Some are 2,000 to 3,000 years old. Forestry scientists from the University of California and Cal Poly, San Luis Obispo,  want to learn more about how disturbance factors affect the health of these aging behemoths.

Growth-response studies to date show that tree vigor can increase following moderate intensity disturbances such as prescribed fire or mechanical fire-hazard reduction treatments. Less certain, however, is how giant sequoias respond to lower and higher intensity disturbances. This information is of critical importance to identify the tradeoffs involved in fire prevention treatments or evaluating management options.

This summer scientists will visit native groves within Giant Sequoia National Monument, where high-intensity disturbances occurred 20 years ago. Harvests conducted at that time removed all trees except for large giant sequoia, creating a forest structure similar to what you’d expect after a high-intensity wildfire. Following the harvests, there was considerable public concern over the fate of the giant sequoias remaining. Mortality and growth in these areas has not been assessed until now.

The primary investigator on the project is Robert York, station manager of the UC Center for Forestry and an adjunct professor in the UC Berkeley Department of Environmental Science, Policy and Management. York is an expert in giant sequoia ecology.  His co-investigator on the project is Scott Sink, a professor in the Department of Natural Resources at Cal Poly, San Luis Obispo. He has investigated differences between old growth and secondary forests and developed expertise in measurements of tree ring growth. The researchers will partner with forest ecologist Steve Hanna of Giant Sequoia National Monument in Porterville.

The scientists will also study tree ring widths taken from 33 giant sequoias at the UC-Whitaker Forest, where light burns and small tree removal occurred in 1967. York previously conducted field work on growth response in a giant sequoia forest subjected to a moderate-intensity disturbance. In addition to publishing a journal article on this work, researchers will hold a field trip for managers of giant sequoia groves, involve UC and CSU students in field and laboratory work, and develop a lab module for coursework at UC Berkeley.

The project is funded by a $10,000 grant intended to foster collaboration in higher education in California on issues affecting agriculture, natural resources or human sciences. In their grant proposal, the researchers said: “We have a unique opportunity to measure growth response in giant sequoia to these different levels of disturbance intensity, and therefore improve our understanding of this species’ complex life-history strategy, while informing management within giant sequoia groves.”

Posted on Wednesday, February 16, 2011 at 8:30 AM

Information on GE Alfalfa

Since the USDA, on January 28th, approved the use of genetically

engineered (GE) Roundup Ready (RR) alfalfa there’s been quite a bit of discussion going on in the media. In Mendocino and Lake Counties we grow very little alfalfa as it is much easier to grow clover/grass hay over a monoculture crop. Also, nutritionally, our livestock producers that feed hay generally can do well with our clover/grass version as it provides all that’s needed for range livestock production. That said, with the irrigation systems in place on some of our former pear acreages, alfalfa production is possible and could certainly be profitable. Certainly, weed-free organic alfalfa would be even more profitable to a hay producer as very little is produced.

Of course, many believe that because alfalfa is insect pollinated, cross-pollination and contamination of non-GE alfalfa could result — some say “inevitable”. Since most of Mendocino County is GMO-free (city limits, Rancherias and State lands are exempt) there is still fear that potential alfalfa producers outside the county boundaries or in adjoining counties, could start growing RR alfalfa and impact those potential alfalfa producers who want to grow conventional alfalfa, organic or otherwise.

In response to some to these concerns, UCCE Agronomy Specialist, Dr. Dan Putnam, has written several publications that will assist those interested to understand the risks and science. They are available for free in pdf format. The first entitled Methods to Enable Coexistence of Diverse Production Systems Involving Genetically Engineered Alfalfa can be downloaded at In addition to explaining the risks of cross-pollination, Dan provides information for testing hay to determine if it is genetically engineered. Livestock producers targeting our local or niche markets should download this publication just for that information alone. A second publication co-authored by Dan and several other UC scientists is entitled Roundup Ready Alfalfa: An Emerging Technology. It can be downloaded at and it discusses further pros and cons. The third publication is entitled Avoiding Weed Shifts and Weed Resistance in Roundup Ready Alfalfa Systems and it can be downloaded at and provides a thorough explanation of the risks of weed resistance.

Posted on Tuesday, February 15, 2011 at 5:43 PM

WSSA Awards and Current Research on Gyphosate-Resistant Junglerice

E colona

I had the opportunity last week to attend the Weed Science Society of America (WSSA) annual meeting which was held in Portland OR this year. The meeting was really interesting as usual with many interesting oral and poster research presentations. Two UCD...

2011 WSSA Poster AlarconReverte GR Colona
2011 WSSA Poster AlarconReverte GR Colona

Posted on Sunday, February 13, 2011 at 9:16 PM

Weed control considerations in vineyards

Capay Valley vineyard Dec2010

Reposted from a paper presented at the 59th annual Lodi Grape Day (February 1, 2011). Weed Control Considerations in Vineyards Brad Hanson, Cooperative Extension Weed Specialist, UC Davis What makes a weed a weed? Better yet, what makes a...

2011 Lodi Grape Day Hanson
2011 Lodi Grape Day Hanson

2010 Herbicide Registration on Horticultural Tree and Vine Crops
2010 Herbicide Registration on Horticultural Tree and Vine Crops

Posted on Sunday, February 6, 2011 at 10:44 AM

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