Over the past few years, herbicides with the active ingredient glufosinate (Rely, Rely 200, Rely 280) have become very important in California tree nut orchards and grape vineyards.

Glufosinate is classified as a "Group 10, or Group B" herbicide an inhibits an enzyme important in the production of the amino acids glutamine in plants.  Although it sounds similar to another amino acid inhibitor, glyhosate (the active in Roundup and others) glufosinate works quite differently than the Group 9 herbicide glyphosate. 

It's that time of the year when I try to update the list of herbicides registered for use in California orchard and vineyard crops.  The attached version has all the updates that I have been made aware of by my industry reps during the year.  However, I have not done my end-of-year-herbicide-label-reading-marathon yet so it may change slightly over the next few weeks once I do that.  Over the next few weeks, I'll try to discuss some of the more important changes in the T&V herbicide landscape. 

Today, I'll focus on what could be important news for vineyard weed managers, registration of a new active ingredient for grape vineyards.  Flazasulfuron (trade name: Mission...

Abstract

Non-synthetic herbicides offer a potentially useful addition to the suite of weed management tools available to organic growers, but limited information is available to guide the optimal use of these products. The objectives of this research were to 1) evaluate the efficacy of clove oil and vinegar based herbicides on weeds across multiple states, and 2) assess the potential role of temperature, relative humidity (RH) and cloud cover in explaining inter-state variations in results. From 2006 to 2008, a total of 20 field trials were conducted in 7 states using an identical protocol. Seeds of brown mustard were sown and herbicides applied to both mustard and emerged weeds when mustard reached the 3-4 leaf...

Ok, I'll admit that I fully intended to do something useful today but got distracted thinking about weed control research, weed science extension, and herbicide-resistant weeds (what do YOU think about on Saturday afternoon?).

Anyway, while procrastinating today, I ran across the blog of one of my weed science colleages at the University of Wyoming, Dr. Andrew Kniss.  In an October post, Dr. Kniss discussed the question "Do genetically engineered crops really increase herbicide use?" that largely discussed the data in a report on the impact of GMO crops on...