For Mid-South farmers Weed resistance growing concern

There are long-term weed and herbicide issues famers must consider if they are in farming for the long haul. One is herbicide resistance, and more specifically, glyphosate resistance.

Two or three years ago I wrote all winter on that topic and not many farmers made changes. That was not surprising. Finding practical answers is much more difficult than just writing about the topic.

The weeds, however, have not ignored the topic and resistance continues to develop. At the same time, most farmers are making few changes in their management practices — at least until they are forced to.

I have been encouraging the weed science group at the University of Arkansas to stay the course and go forward with its weed resistance message that a lot of folks do not want to hear.

They are out front in developing resistance management programs. I predict the University of Arkansas weed group will be quickly recognized among the national leaders in this area.

I encourage you to heed their message. I enjoy quoting farmers because they usually “say it best.” In a discussion not long ago with a farmer who calls me a lot, we were on a topic unrelated to herbicide resistance. He related what we were talking about to resistance, however, and said, “The first few times I heard you and the university guys talking about Roundup resistance, I thought, ‘Big deal!’”

He went on to say, “Well I got a big dose of resistant marestail this year. After spraying three times and still losing two fields of soybeans to it, I found out it is a big deal!” (His remarks were considerably more colorful, but you can get the idea.)

I can relate to the farmer because the marestail issue has been bigger than I thought it would be. There are, however, reasonably good alternative herbicides and tillage practices for this weed. Good management information is available from the University of Arkansas as well as the universities in neighboring states.

I predict the weed that will force more unwanted management change will be Palmer pigweed. I predicted it would be the first major weed to develop glyphosate resistance in the south, but that honor went to marestail.

I will stay the course, however, in predicting that a widespread pigweed resistance problem will be ugly. I feel strongly about this, because I got the “postgraduate course” on Palmer pigweed as a rookie Extension specialist in the mid 1970s.

As I would get pigweed questions from the sandy soil areas of the state, I would give the standard college boy answer that they were either not using enough Treflan or they were not incorporating it properly.

Farmers have good memories and some even take notes when it appears they are sleeping in the meeting. After a couple of years, one stood up in a meeting with his notes from previous meetings and said, “Since you know so much about it, why don't you come up here and show us.”

Of course, I jumped at the chance to strut my stuff and went up to Newport the next year and put out a big Palmer pigweed demonstration. I really showed them — there wasn't a treatment in the test that was not overgrown to the point we could not harvest it.

A little later, Scepter came along and worked well for a couple of years before resistance developed. Then Roundup came along and we actually had some fun demonstrations and field days at Newport.

If we lose Roundup, where do we go? We have already tried everything else. The weeds are talking, are we listening?

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