Blog Post

Mid-Season Tough Weed: Waterhemp

This agronomic photo shows young waterhemp.

In addition to soybean and corn seedlings, keep an eye out for one of the toughest weeds out there: waterhemp. While late-emerging waterhemp doesn’t pose as big of an immediate threat to yield as it does earlier in the season, it can deposit up to 1 million seeds in the soil bank, contributing to future problems.

Identification

  • Absence of hair
  • Glossy and elongated leaves
  • Stem color varies from light green to dark red

After applying a pre-emergence herbicide, the next step is to apply a timely post-emergence herbicide with residual components to manage waterhemp before it reaches 4 inches. The University of Illinois reminds growers to use multiple effective modes of action on target weeds in a post-emergence application. Using the recommended rate of a post-emergence herbicide like Acuron®, Acuron® Flexi or Halex® GT herbicides in corn, and Flexstar® GT 3.5 herbicide in soybeans is an effective approach in managing waterhemp.

Because waterhemp has developed resistance to many different herbicide classes, scout your fields throughout the season to determine the effectiveness of your herbicide applications. Also, consider complementing your herbicide program with mechanical control methods and/or hand removal to avoid waterhemp escapes from going to seed.

Ready to scout for waterhemp and other tough weeds? Test your weed identification knowledge first by taking the Resistance Fighter® Weed IQ Quiz.

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All photos are the property of Syngenta or are used with permission.

©2017 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your local extension service to ensure registration status. Acuron is a Restricted Use Pesticide. Acuron®, Flexstar®, Halex®, Resistance Fighter®, the Alliance Frame and the Syngenta logo are trademarks of a Syngenta Group Company.









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