INDIANAPOLIS — Every year, farmers attempt to kill weeds that are harder and harder to control.

To address these concerns, Bayer Crop Science hosted a panel of experts. They discussed weed resistance and management strategies as farmers look to the 2017 planting season.

“Unfortunately, in many cases, what we’re seeing are weed populations that have evolved resistance and are no longer effectively controlled by whichever herbicide the farmer applied,” said Aaron Hager, Extension specialist at University of Illinois.

“Weed resistance to herbicides is something farmers have had to contend with literally for decades. But we’ve seen some new, significant challenges … We’ve lost the effectiveness of many of our herbicide chemistries that we used to be able to control our weeds with.”

Hager talked about a recent study conducted at the University of Illinois that examined herbicide resistance.

The analysis showed three key points:

1. The best indicator of whether there was glyphosate resistance in a particular field was related to herbicide management factors. The decisions the farmer made, such as the products they used, were crucial.

2. Tank mixing more than one effective herbicide was a better mitigation strategy than rotating from one herbicide to another.

3. Proximity to a confirmed glyphosate-resistant population was a poor predictor of whether or not resistance would evolve.

Resistance Spreads

“In a relatively short period of time, we’ve confirmed resistance in Illinois waterhemp to six different sites of action. If a farmer had an issue with glyphosate resistance in one field and another type of resistance in a second field, it creates challenges for remembering and knowing what we can’t use where. Where we really see the issue going for many farmers in the Midwest is not just resistance to a single herbicide, but what happens when you combine multiple resistances together?”

Growing Challenge

“If we take a look at where we are this year, in my geography we know we have fields with PPO, glyphosate, dinitroaniline and ALS resistance. All of this resistance is stacked. It’s becoming more and more challenging to grow a crop. It’s a quite unfortunate because when we plant the wrong technology today, there’s absolutely no options post-emergence. We’ve had growers, in my geography, that have had to put a disc in the field and start over … I think one key piece is picking the correct technology to place in the field.”

Complete Solution

“We took part in market research here recently where we spoke with 3,000 growers. What we found out is that 67 percent of the growers we spoke to had resistance on their farm … As we translate that to the U.S., what we’re looking at is 91 million acres. That’s an entire corn or soybean crop in the U.S. … LibertyLink is the only working, non-selective herbicide, getting both broadleaf and grasses. There’s no known resistance in row crops in the U.S. We are effective. When you couple that with a complete, complementary weed control program, you will get and see clean fields.”

Erica Quinlan can be reached at 317-726-5391, ext. 4, or Follow her on Twitter at: @AgNews_Quinlan.


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