It wasn’t hard finding Palmer amaranth dotting fields in the Midwest and South last summer, and many of this pigweed species were herbicide resistant. Showing the degree of resistance, mainly to glyphosate herbicide, was easy for Bayer CropScience at their “Respect the Rotation” demonstration plots held across the two regions in 2012. 

At a site near Collinsville, Ill., earlier this year Bryan Young, professor of weed science and agronomy at Southern Illinois University, said, “If someone looked at the ground here and saw black specs like pepper, that’s Palmer amaranth weed seed. That shows you how abundant the population and the weed seed is from the plants in this field. Resistance isn’t going to go away. Farmers are still going to have to deal with it.”

“More than at any time in our history, farmers must manage for weed control or face the loss of productivity, sustainability and their legacy to future generations,” Tom Nash, Bayer CropScience technical service representative explained. “These integrated weed management practices provide a solid foundation to preserve conservation tillage, steward additional herbicide-tolerant technologies and promote sustainable and profitable row crop production.”

Local grower Mike Mueller of Clarence, Mo. agreed. “What I got out of today I can summarize in one word—scared. I see 10-foot tall Palmer amaranth lying around here and I think about the resistant giant ragweed on my farm. We need to be rotating. We’ve abused Roundup in the past and we cannot do that with LibertyLink.”

The Respect the Rotation initiative, conducted by Bayer CropScience and local university scientists, promotes rotation of crops, herbicide-tolerant traits and modes of action to encourage greater diversity in herbicide programs and reinforce the principles of Integrated Weed Management. It encourages the use of multiple chemical, cultural and mechanical control methods where feasible.

LibertyLink is the seed trait, in conjunction with Liberty herbicide, that Bayer CropScience mentions as the number one alternative to glyphosate tolerant crops in the Respect the Rotation events.

But Nash explained the Respect the Rotation events more by saying, “The goal of the initiative is to promote farmer adoption of diversified management practices that help manage or prevent glyphosate-resistant weeds, as well as promote stewardship of viable alternatives.”