- Author: Brad Hanson
A quick post today on a recent report of resistance to glufosinate, the active ingredient in Rely herbicide (also sold as Liberty, Ignite, Basta, etc in other markets).
Researchers in Malaysia reported a few years ago on a population of goosegrass resistant to glufosinate in vegetable and orchard systems (Lee L J & Ngim J (2000). A first report of glyphosate-resistant goosegrass (Eleusine indica (L) Gaertn) in Malaysia. Pest Management Science, 56, 336-339). For a number of years this was the only reported case of resistance to this herbicide.
At a meeting last month, I saw a presentation by Wilson Avila and Carol Mallory-Smith from Oregon...
- Author: Brad Hanson
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 weed scientists, Joe DiTomasso and Kassim Al-Khatib, were honored with the Society's Fellow Award - the highest level of recognition given by the group. More info on this award can be found here: http://www.wssa.net/WSSA/PressRoom/WSSA-2011-AwardWinners.htm
I've attached a research report presented by a UCD...
- Author: Brad Hanson
I've made a couple posts about herbicide resistant weeds but I thought today would be a good time to go back to the basics for a moment. Occasionally, there is some confusion about the definitions of a "resistant" weed versus a "tolerant" weed. Although on one hand a definition seems like a pretty basic starting point, there was considerable debate about how to define herbicide resistance. The Weed Science Society of America (WSSA) [http://www.wssa.net] eventually settled on the following:
"Herbicide resistance is the inherited ability of a plant to survive and reproduce following exposure to a dose of herbicide normally lethal to the wild type. In a plant, resistance may be...
- Author: Brad Hanson
This is one part follow up to my previous post on glyphosate resistance and one part test of a tool to imbed articles in the blog.
The above frame has a 2008 report that Anil Shrestha, Kurt Hembree, and I wrote for California Agriculture on our glyphosate-resistant hairy fleabane work. You can click on it to open it in a full-screen reading pane.
I like this document hosting interface and may use it again. If you have problems viewing it in a particular browser, please let me know.
The article can also be downloaded here
Brad
- Author: Brad Hanson
I thought I'd followup on my post last week about herbicide resistant weeds with a little more detail on our recent (and ongoing) work on glyphosate-resistant horseweed (Conyza canadensis) which is also known as mare's tail.
In 2006 and 2007, we conducted research to determine the magnitude of the glyphosate-resistant horseweed problem in the Central Valley. The sampling was focused at that time in the Fresno area but included sampling as far south as Wasco and as far north as Marysville. We published the results of the initial project in 2009 (Weed Science 57:48-53) but the work has also led to several related projects which are ongoing.
In general, we found that:
1. Glyphosate-resistant horseweed was...
