Farm Progress is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Serving: United States

Glyphosate-resistance shocking

I recently wrote in an article that I would sure like to get called out to a “normal-looking” rice field because I have looked at so many messes this year.

I have been pleasantly surprised by the calls I have received from farmers bragging about their crops and inviting me to come look.

The crop is beginning to look like a rice crop and I have been in several areas where it really looks good. I have not enjoyed the late-June heat, but the crops sure have.

I continue to hold to my optimistic view that if we have a hot September and dodge the hurricanes we will make lemonade out of lemons with this crop. I personally do not enjoy hot Septembers but I can this year if it will pull a rabbit out of the hat.

My calls are the basis for a lot of articles and I often write about one person’s call or story without naming them. It is always interesting to see if they recognize themselves and call me.

I recently received one from a farmer who gets excited pretty easily, and he sounded on the verge of hyperventilating when I answered. He reported that he had recently made his first glyphosate application across his farm, and the pigweeds in one field did not die. He went on to relate that he noticed more pigweeds in the field from the combine last fall than he felt he should have but passed it off as misapplication.

I have no data to confirm these are resistant, but the chances are very good that they are. When I told him that chances are he had a problem, his response was, “Chances are I am in SHOCK.”

He asked how they could spread so fast and I reminded him that each seed-producing pigweed plant is capable of producing 200,000 seeds. He went on to ask, “What can I do now?” My reply was, “Learn all you can about LibertyLink soybeans this year.”

The University of Arkansas weed scientists as well as scientists in surrounding states are preaching glyphosate-resistance from the housetops. It is not totally falling on deaf ears as there do seem to be a lot more herbicides such as Valor, Prefix and Flexstar being used in Roundup Ready programs. This is a good thing and I encourage more of it.

However, I am concerned that there is a misconception about the level of resistance management this really provides. While the use of alternative herbicides can help, this concept has limitations.

Ken Smith, University of Arkansas weed scientist, commented in a meeting last winter that in order for an alternative herbicide to be a true resistance management tool in a Roundup Ready program, it must be capable of providing 100 percent Palmer pigweed control. He went on to comment that we do not have any conventional herbicides that will consistently do that.

He also contrasts what he calls resistance management and managing resistance. My country boy way of saying it is there is a huge difference between preventing resistance from occurring on your farm and fighting it after you get it.

Do not be shocked when glyphosate resistance shows up if you keep feeding the weeds a steady diet of glyphosate. It is not a mater of “if” but “when.”

If you prevent glyphosate resistance from ever occurring on your farm, then glyphosate remains the great broad spectrum herbicide it has always been for you. If you push the technology until resistance occurs, then it may never be the herbicide it once was for you.

Where the problem has not yet occurred, using alternative herbicides can help, but I am concerned that the expectations are too high. I believe the introduction of LibertyLink soybeans is huge and I encourage you to look at some or look at someone else’s this year. It is excellent technology that provides a broad spectrum over-the-top alternative to a glyphosate program.

If you do not want to be shocked into managing resistance after it occurs, my suggestion is to make use of every available tool you have. You have some great opportunities to rotate Roundup Ready crops with LibertyLink crops (both with alternative conventional herbicides included) with Clearfield rice and conventional rice. If you are not in front of resistant weeds, you are behind them.


TAGS: Soybeans
Hide 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.