A warmer than usual winter might lead to a higher population of marestail than previous years. Since conditions favor the weed, it’s important to gain control early so it doesn’t steal yield.
“As we go into spring, I think farmers need to be aware of how much marestail is in their fields,” says Travis Legleiter, weed science program specialist at Purdue University. “I think this spring we may have more marestail, or marestail that’s further advanced in its growth stage, than we’ve had in the past.”
Use burndown to gain early season control of the weed, but be mindful of herbicide best management practices. Make sure you’re using an effective herbicide in a mix that targets multiple sites of action. Legleiter advises avoiding 2,4-D and glyphosate for burndown. Marestail is easiest to kill between 2” and 4” tall; after that, the process becomes more difficult.
Make sure your herbicide is not among the groups in which marestail is resistant. These include five herbicide groups, PSI Electron Diverter (22), EPSP synthase inhibitor (9, glyphosate), ALS inhibitors (2), Photosystem II inhibitors (5) and PSII inhibitors (7).
Use multiple, effective modes of action to combat this hardy weed, and use other methods to attack areas of weaknesses. Marestail does not recover from deep tillage very well, and it really suffers when the crop reaches canopy. Continue to scout after tillage and herbicide application to determine weed kill and where you may have resistance issues.