Last entry I talked about the problems with artichoke thistle (Cynara cardunculus L.) in the Sacramento Delta and other coastal regions. Again, this thistle was introduced to California as the cultivated artichoke, but escaped to become a serious rangeland weed.

Because stands of artichoke include perennial adults, new seedlings and a persistent seedbank, the best means of control is likely to be broadcast application of a selective herbicide with both foliar and soil-residual activity.

Starting in fall 2010 we tested several such treatments at a dense infestation of artichoke thistle in the Montezuma Hills, Solano County. We made applications at three timings: fall (December 16, 2010), winter (January 26,...

Part of my job as the Director/Farm Advisor at the Intermountain Research and Extension Center involves overseeing weed management programs for a variety of crops and non-cropland at the Center.  Over the last month, I’ve observed the outcome of these programs as many of the crops are nearing harvest.  This spring I would have given myself an “A” grade for weed control.  We treated crop fields with a combination of control methods and made an aggressive push to control weeds along roads, ditches, and field borders.  Unfortunately, as time goes on I think I need to downgrade my performance to a “B” because some fields and roadsides now have quite a few weeds.

In reviewing field records, one factor was a common denominator at...

Over the weekend, the Sacramento Bee published an article discussing the invasiveness and spread of yellow starthiste (Centaurea solstitialis) in California. http://www.sacbee.com/2011/08/21/3847369/invasive-yellow-star-thistle-aims.html

 It was written as an "interview" with the weed which, although a little cute for me, may help the general public understand a bit more about yellow starthistle which currently infests over 15 million acres of rangeland and noncrop areas of California.

For folks interested in more scientific information on yellow starthistle biology, ecology, and management in California and other...

Today I'm asking for input from folks who work in orchard and vineyard weed control (land owners, managers, pest control advisors, sprayer operators, etc.) on your take on herbicide resistant weeds.  What have your experiences been and what are your concerns?

Below is a link to an online survey to find out what tree and vine weed managers think about herbicide resistance.  Your responses will be kept anonymous but the overall trends will be helpful for planning research and extension programs.  Eventually, the results of this survey will be coupled with the results greenhouse testing of weeds collected throughout the state.