Whats The Deal With Gramoxone?

Sep 22, 2018


Duke Spraying

As I’m sure everyone is aware, there seems to be cases where “Gramoxone just doesn’t work like it used to.”  

There are lots of theories floating around out there about changing formulations, Chinese owning Syngenta and diluting the strength, and many more.  

While many instances can be traced back to some sort of variable that affected performance, I have walked plenty of fields where everything was done right – rate, adjuvant, speed, water, droplet size, pressure, temperature, sunlight, etc.

While there are no concrete answers to this, and Syngenta has acknowledged the issues, here are some points to consider:

  1. Gramoxone is a desiccant.  Which means it’s job is to literally wreck anything green it touches.  If it doesn’t touch a plant or plant part, it won’t be affected. Taking down 4 foot kochia with 2 inch wide stems is not going to be that effective, even with 30 gal/acre of water.
  2. We have had so many Gramoxone applications through the years in NE Montana that it is very possible we have been selecting for kochia that is much less leafy, has more growing points, and harder to kill.  This is different from resistance with Roundup. Pure selection of biotypes that can adapt to try to survive. You can even look at a field today and notice kochia that “just doesn’t look like kochia”.
  3. Many lentil fields had some sort of residual chemical carryover from last year, or were damaged by this spring’s preplant burndown.  While a lot of them grew out of it, things like that can harden off stems and in certain cases (such as knolls where they seem to stay green and deformed forever) the green is “locked-in”.  Gramoxone just doesn’t do well in those cases.
  4. It’s more expensive, but in cases where Buckwheat, Lambsquarters, and more were heavy throughout the field, the best combination was a Sharpen/Gramoxone/Strikelock/Class Act mixture.  Attached is a picture of this.
  5. I know a lot of you are fighting green stems in lentils, even when 7-10 days have passed since application.  Where there was no chemical damage, everything was applied correctly, etc…, there just isn’t a great answer as to “WHY?” right now.  I’ll keep you posted as we work with Syngenta for answers.

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