While the opportunity to plant corn early was welcomed by no-tiller across the Midwest, early planting means the weed competition period will be extended compared to the last 2 years, a weed specialist with Syngenta Crop Protection says.

Because of the early season, the first flush of germinating weeds may not have been controlled by a burndown herbicide, Gordon Vail says. Therefore, weed populations may be heavier and more difficult to control during the corn growing season. 

Vail says no-tillers are likely to see early germinating weeds like waterhemp, giant ragweed and lambsquarters as more problematic this year and will need to make a stronger effort to control them for an extended period of time. For those relying on a post-emergence herbicide program, early application will be essential for control.

“These weeds should be controlled early by using a reliable post-emergence herbicide rather than taking a chance with just glyphosate alone,” Vail says. “This is not a year to gamble on effective weed control.”

This season, no-tillers will need to consider the following regarding their post-emergence herbicide applications:

  • Closely scout fields to determine proper application timing.
  • Post-emergence herbicides are usually more effective when sprayed on weeds that are less than 4 inches tall.
  • Choose a herbicide with multiple modes of action in lieu of using glyphosate alone. A herbicide with residual activity is helpful to manage problematic weeds and grasses like lambsquarters, waterhemp, foxtails and ragweeds up until crop canopy.