Arkansas’ Clay County is largely known for its excellent cotton. However, if not for the recent collective effort of producers, it could easily be known for its resistant pigweed. 

Glyphosate-resistant weeds are not a novelty to area farmers. Before major populations of resistant Palmer amaranth showed up, they had to deal with resistant horseweed.

“We actually learned how to deal with horseweed using dicamba and Roundup Ready crops,” says Andy Vangilder, Clay County Extension staff chair. “We’ve done a good job on horseweed.”

Then, three or four years ago, farmers began finding Palmer amaranth that looked to be resistant. In 2009, Vangilder sent samples off for evaluation. They came back at resistance levels of 7 to 10 percent.

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In the fall of 2010, “big clusters of pigweed – car-size patches -- showed up in areas we’d sprayed and taken care of properly. I sampled three fields and those numbers came back at 55-, 85- and 100 percent resistant. At that point, we knew pigweed was about to blow up and cause our fields major problems.”

Vangilder began talking to Ken Smith, University of Arkansas weed scientist. Following Smith’s suggestions, “we had a meeting with our agri-dealers in the area. We said ‘this is what’s happening and this is what it will take to control these resistant weeds.’ They said ‘if you’ll put this on paper, give us your recommendations, we’ll do it.’ So, we put together a fact sheet for Clay County and our dealers brought in the needed products. They made sure our farmers had the chemicals.”

Several of the leading farmers in the county then “started to talk about doing more, going with ‘zero tolerance’ of pigweeds. They began spraying their turnrows, chopping and keeping things really clean. More folks began doing the same and we’ve continued it through this season.”

Farmers, watching the encroachment of hard-to-kill pigweeds, were anxious “to get ahead before it got too bad,” says Vangilder. “And we still have grown-up fields that folks haven’t paid enough attention to. But drive around this northeast Arkansas area and I don’t think there’s anywhere cleaner in the state.”

During a recent tour of the area, “Smith was impressed with what the farmers here have been doing. It isn’t just the fields – they want it all clean. They got hooded sprayers that won’t drift as much.”

As for the areas in the county where pigweeds are still evident, “you have to understand it isn’t due to laziness. One of the problems, of course, is we flooded so badly up here early in the season. The corn was behind, planting of crops dragged. That meant there was much less time to spray these resistant pigweeds.”’

However, Vangilder says such circumstances don’t absolve the need to keep one’s property pigweed-free. “Certainly seeing your neighbor’s turnrow is clear while yours is grown up plays a role in everyone picking up the pace. There’s some subtle pressure there. Everyone is starting to improve their efforts and I think 2012 will even be better.”