Good news for minor tree crop weed managers - Chateau SW (active ingredient: flumioxazin) recently received a Supplemental Label that allows use in bearing olive and pomegranate orchards. 

Flumioxazin is a cornerstone preemergence herbicide for many tree and vine crop weed managers.  Prior to this supplemental label approval, it could only be used in non-bearing olive and pomegranate.  This allowed time for the manufacturer and the USDA-IR4 program to complete the residue testing neccessary for use in bearing orchards (standard proceedures).  I'm glad to see this bearing label as it gives another weed management tool for these increasingly important crops in the state...

A few weeks ago, a new herbicide from FMC Corporation was registered for use in some California orchard and vineyard crops. 

Zeus herbicide, with the active ingredient sulfentrazone, now has a supplemental label in the state that allows use on grapes (wine, table, raisin, and juice-types), lemon, orange, pistachio, and walnut (black and English).  You can find labels, and MSDS info from FMC  here:http://www.fmccrop.com/grower/products/herbicides/zeus.aspx

Sulfentrazone is a preemergence herbicide that can...

Earlier this year, Lynn posted an explanation of herbicide modes of action and what that means for herbicide resistance management in orchards and vineyards.  

I thought to myself "Self, we should put this in a table so it would be easy to understand".  Then I remembered that we actually did this already in one of the four glyphosate resistance publications that I mentioned in an August posting.

Here's an excerpted table from ANR Publication 8501 "Preventing and Managing Glyphosate-Resistant Weeds in...

In the past couple of years, I've gotten a lot of questions about goosegrass in orchard production systems, particularly about suspected glyphosate-resistant biotypes.

From a California orchard standpoint, we have two main goosegrasses (Eleusine spp) to deal with; these are goosegrass (Eleusine indica) and threespike goosegrass (Eleusine tristachya).  These species are fairly similar but have quite different flowers (see the photo below). 

According to the Weeds of California and Other Western States, goosegrass is a summer annual (or occassionally a short-lived perennial) while threespike goosegrass is a perennial (or sometimes...