- Author: Chris McDonald
How many times do we see some plant that looks unusual, we let it sit for a while, pondering its existence (maybe that's just me), and then realize its some plant we have never seen before? In that moment we try to find it again and its either gone or gone to seed!
One concept that is difficult to grasp is exponential growth. This is not the basic math, growth model that is familiar (if I have earn $5,000 selling seeds, then after ten years I'll have $50,000, yeah!). Its like growth on steroids. This is the growth that produces stunning results that boggle the mind. I think we have all seen the gimmicks, chain letters and recipes, facebook posts giving 5 people good luck, Bernie Madoff they are all based on exponential...
- Author: Brad Hanson
Residual or soil applied (ie. preemergent or PRE) herbicides can provide many benefits to weed managers. In contrast to foliar-applied (postemergent) herbicides that only affect the weeds present at the time of the application, residual herbicides persist in the soil and have activity on weeds that germinate after the application. Depending on the chemistry of the specific herbicide, the rate applied, weed spectrum in the field, and environmental conditions, weed control may last for several weeks or months.
When performance problems arise with residual herbicides, they usually take the form of either unexpectedly short or unexpectedly long residual activity. As illustrated in the line diagram below, our goal with residual...
- Posted By: Brad Hanson
- Written by: WSSA press release
The Weed Science Society of America (WSSA) recently released a series of free online training modules on understanding and managing herbicide resistance. The target audience for the five modules is consultants/field advisors/agronomists but I think any weed managers could benefit from them.
According to David Shaw, the chairman of the WSSA Herbicide Resistance Education Committee "When farmers have a better understanding of herbicide resistance and how to manage it, they can adopt proactive management programs that delay or mitigate the evolution of herbicide-resistant weeds".
The five training modules include:
Lesson 1:...
- Author: Cheryl A. Wilen
Just a quick note about soil seed banks. If you are not familiar with the term, it is where seeds are stored in the soil until conditions are appropriate for germination or where they decompose. There are thousands of seeds in a seed bank and not all will germinate at any given time or any given set of conditions. That's one of the reasons annual weeds are a problem year after year, even if you kill the current year's weeds before they produce seeds.
If you need proof, I'm attaching a photo of a plot that was tall fescue turf for the past 5 years and there were few weeds in the plots. I then shut off off the water for a few months and the fescue died. I recently started irrigating a few plots and up came a bumper crop of...
- Author: Brad Hanson
... well, a new name and new uses for a familiar product anyway.
I received a notification today that Dow AgroSciences received California registration for TrellisTM herbicide for use in grapes and tree nuts.
The active ingredient in Trellis, isoxaben, may be familiar to folks who have used Gallery T&V herbicide which was registered in 1998. This is a residual herbicide that will provide several months of control for a fairly broad range of broadleaf weeds (minor activity on some grasses). For more info, go to the UC Weed RIC "herbicide susceptibility chart" and scroll down to isoxaben (Gallery) in the herbicide window or read the Trellis label...