Strategies Emerge In Resistance Fight

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Waterhemp

Reports of weed resistance continue in many regions, but the breadth of the CropLife 100 reporting companies’ experiences gives an especially helpful overview of the situation. Eighty-three firms weighed in on glyphosate resistance, with fully 57% of them saying it was a major problem on some or many fields they serviced. About one third reported it was a relatively minor problem.

Let’s start with the regions where the news is better. Brent Low, vice president of sales and marketing with Ag Partners LLC, Albert City, IA, reports additional applications of herbicides the company’s territory, which covers the northern half of the state, have not been necessary this year. Lane Mielke, sales and marketing manager with North Central Farmers Elevator (NCFE), Ipswich, SD, has also found limited resistance, but says it’s “sure a concern on growers’ minds, and they’re starting to do more like change modes of action — trying to keep glyphosate for a long time.” Mielke says his sales force has been trained to recommend better farming practices using multiple modes of action. In fact, NCFE is doing a lot more tank mixing for customers. “The farmers like it when they can just throw Roundup in the tank and spray, but when it gets more complicated, they often seek help from us,” he says. He also says the company’s growth in custom application can be attributed to personnel problems: “With the condensed springs we have had, the importance and timeliness of planting and spraying is what’s helping drive application growth.”

Steve Briggs of South Dakota Wheat Growers, Aberdeen, SD, acknowledges his producers have not been impacted by resistance as much as others  in the midsouth and southeast, “but we do know if we do not manage our fields effectively, our day is coming,” he says. “Growers have seen horror stories in magazines.”

His company heavily promotes the use of residual herbicides and recommends alternative herbicide programs and rotations when necessary to head off future problems. He’s found that progressive, large-acreage growers are demonstrating they’re willing to invest in a weed management program so they can hold off resistance.

Harder Hit

The situation varies across Illinois. Jeff Eggleston, agronomy division manager with Hintzsche Fertilizer, Maple Park, IL, says weed resistance in his territory is not widespread, but it’s “slowly creeping forward.” Brandt Consolidated, Springfield, IL, is facing tougher times. Tim McArdle, general manager of the agronomy division, says resistance has become a huge problem for the ag industry there. He is glad there are still “tools in the chest” that will provide some kind of control, but he says the company is getting more complaints about weeds that just won’t die no matter what is put on them.

“I don’t think we can look to the crop protection companies to provide some kind of magic bullet product — like glyphosate was — in the near future,” McArdle says. “Maybe in 10 to 15 years something might be available, but not any time soon.”

Resistance also varies greatly across MFA’s territory, which includes all of Missouri and parts of Kansas, Arkansas and Iowa. “We’ve got some spots where it’s really bad — almost every acre has resistant weeds on it. It really blew up this year,” says Craig Childs, senior vice-president of Agri Services headquartered in Columbia, MO. Other issues in that state have been resistance in giant ragweed, and in Missouri’s bootheel, some problem palmer amaranth.

Childs notes that in the past few years there’s been some resistance “denial” among customers, but this past season, the problem was widespread enough that everybody is convinced of the reality.

That new reality includes trying different products. For instance, Crop Production Services, Washington Court House, OH, sold a lot of 2,4-D and Salvo to help control resistant marestail. The results were disappointing. Steve Mossbarger, facility manager at CPS, says he still saw plenty of marestail in fields in 2011 — and believes it will continue to be a “big problem” down the line as well.

Farmers are accepting the fact that they need to go back to using more preplant chemicals and more post residual chemicals to control glyphosate-resistant waterhemp, says Agri Services’ Childs.

Fortunately, some planting systems are more effective against herbicide resistance build up. In Pocahontas, AR, Kyle Baltz, manager of Baltz Feed Co., says his region’s rotation of rice and corn tends to kill off most weeds that might develop resistance from one year to the next. “So it’s not horrible in our area, but there are horror stories,” he says. For instance, flooding in 2010 caused weed seeds to float from one field to the next — so weeds needed control in areas they’d never appeared before.

The strategy in 2011 was to use preemerge products, with more dollars clearly going into weed management than Baltz had ever seen in the past. “Ultimately, we could see more growers in our area going back to plowing their field to try to control these new weeds,” he says.

Wade Blowers, COO for Hamilton Farm Bureau, Hamilton, MI, believes the resistance situation has created opportunities for retailers because they will need to start using different products. “This will make weed control more of a specialized art than simply a put-on-one-product. Before glyphosate, it used to be that weed control was more of a science, driven by knowledge and research. That’s coming back,” he says.

Heacox is a Contributing Editor for the CropLife Media Group, which includes CropLife and CropLife IRON magazines, and the PrecisionAg Special Reports.

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