When Weeds Emerge in Midwest Cornfields | The More You Grow | Corteva Agriscience
 4/26/2022

When Weeds Emerge in Midwest Cornfields

Something went wrong. Please try again later...
Early corn

If there’s one thing corn farmers know, it’s that weeds are much easier to control before they emerge or when they’re small. Once those weeds mature, they become significantly more difficult to take down. So understanding when those troublesome weeds are likely to emerge in your cornfields can help you tailor your herbicide applications to control them before they have a chance to rob your corn yield.

This weed emergence timeline features photos of nine herbicide-resistant species commonly found in Midwest cornfields, when they’re likely to emerge and how long their emergence period typically lasts. Download the graphic for a handy reminder you can refer to in the field.

Here’s a quick rundown of the weeds and information on the graphic:

  • Marestail — fully emerges in fall or early spring ahead of corn planting.
  • Common lambsquarters — can emerge ahead of corn planting and well into the season.  
  • Giant ragweed — can emerge ahead of corn planting and well into the season.
  • Kochia — can emerge ahead of corn planting and well into the season with multiple flushes. 
  • Palmer amaranth — can emerge at corn planting and well into the season with multiple flushes.
  • Waterhemp — can emerge at corn planting and late into the season with multiple flushes. 
  • Giant foxtail — can emerge at corn planting and for about two months after.
  • Common ragweed — can emerge at corn planting and for about one month after. 
  • Morningglory — can emerge after corn emergence for about two months.

Herbicide-resistant populations of all these weeds have been found in the Midwest, and they’re all capable of negatively impacting corn yield. We recommend using a program approach with multiple modes of action and residual activity to control these weeds. Find the right corn solutions to combat these weeds in your fields at PowerOverWeeds.com