Glyphosate-resistant waterhemp rising
Looking back on this year's growing season in Indiana, one weed specialist says for him, one lesson stands head-and-shoulders above the rest.
Throughout this season, Purdue University's Bill Johnson says he's seen a growing number of incidents of glyphosate resistance in waterhemp in Indiana soybean fields. It now has the common weed poised to be the "major threat to soybean production" in next year's crop if farmers aren't careful.
"We've had an increasing number of complaints about glyphosate's failure to control waterhemp in soybean production," Johnson says in a university report. "The number of calls we have been getting on that has essentially doubled each year over the last couple of years."
Though it's found everywhere in Indiana as well as other Corn Belt states, Johnson says the weed's highest concentrations are being uncovered in southern, southwestern, northwestern and east-central parts of the state, a report shows.
If you're like a lot of the farmers Johnson's talked to this year and are facing growing glyphosate-resistant waterhemp populations in your fields, he advises taking it on with more than a single-pass herbicide system next year.
"It is very common to have to spray a field multiple times to get the waterhemp under control," Johnson says. "One-pass herbicide programs are not going to be effective on it because it has a very long emergence pattern."
Now is the perfect time, too, to make that call. Johnson advises documenting existing waterhemp populations now during harvest to get a sense of how much you could be facing next year. "That will help them determine a plan for better controlling it," he says.