Palmer amaranth University of Illinois
PESKY PALMER: Palmer amaranth can cause yield losses up to 80% in severely infested soybean fields and is resistant to six classes of herbicides.

Xtend weed management: expectations versus reality

One shot may not be enough

I am getting many calls, texts and, indeed, pictures of live pigweed from frustrated and worried folks who were expecting dead pigweed within a week of application of Engenia or Xtendimax. Of course that has not been the case.

The first year a new weed control system is used widely by famers is when everyone’s expectations meet reality. The two expectations going into Xtend was there would be a lot of drift and easy Palmer amaranth control was finally back. In Tennessee, both of these expectations in the early going have proven to be unfounded.

The expectation I shared with many is there would be many drift complaints by the first week of June.  The reality is there have just been a couple. This is very encouraging and everyone please keep up the good stewardship work applying Engenia or Xtendimax on your crop. What happens through the months of June and July will tell the tale of how well we stewarded these herbicides.

Clearly most everyone believed all the Xtend farm press ads stating “The field was spotless.” However, the data and experience I had to draw from had shown that though dicamba could be a tool to help control pigweed, it was far from a silver bullet.

Weed management with Xtend works best in a program where PRE emergence herbicides are utilized and residual products are added in POST emergence. The most consistent Palmer amaranth controlling herbicides in that system are Zidua, Dual Mangum, metribuzin and Outlook and premixes that contain those herbicides. Engenia and Xtendimax need to complement those residual herbicides not the other way around. Then, a sequential POST application often will be needed to control Palmer.

In soybean, some have tried tank-mixing a fomesafen product in with either the Engenia or Xtendimax to help the pigweed control. In our research this tank-mix has provided better Palmer amaranth control than going with the dicamba product alone. However, the Palmer population here at Jackson is still mostly susceptible to PPO herbicides and it is still unclear if that tank-mix will work as well on populations with higher levels of PPO resistance. 

If you use a fomesafen and Engenia or Xtendimax tank-mix remember not all fomesafen products are labeled to be tank-mixed. The only fomesafen tank-mix labeled with Engenia is Sinister from Helena, while Xtendimax label has several fomesafen options including Flexstar, Reflex and Warrant Ultra. Make sure to check the labels on line as they are being changed daily so other fomesafen products may be added shortly.

TAGS: Soybeans
Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish