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Finalize Your Soybean Weed Management Plan While Ramping up for Planting

April 23, 2018
This agronomic image shows frozen soybean fields in the Midwest.

Cold temperatures in the Midwest cause planting delays.

Following up on our earlier post, here are some late-planting tips – specific to weed control – for you to review while waiting for temperatures to rise in the Midwest.

With planting delayed in the Midwest, this is a good time to solidify your weed management plan to help your soybeans grow strong. Late-planted soybeans are more vulnerable to early- and late-season diseases, and inadequate weed control can compound issues during the growing season because late-planted soybeans have less time to mature. Once conditions are favorable, weeds will emerge quickly. A robust, flexible weed management strategy is key to helping decrease stress and nutrient competition for your soybeans.

A major concern in the Midwest, especially for late-planted soybean acres, is how to deal with glyphosate-resistant weeds. Kansas State University agronomists say resistant Palmer amaranth and waterhemp are causing major problems throughout the Midwest. These weeds are developing resistance in a very short timeframe, making them difficult to control.

The University of Nebraska recommends that you start with a pre-emergence herbicide for early-season and herbicide-resistant weed control. Pre-emergence herbicides come with a variety of benefits including:

  • Reduced yield loss due to weed competition
  • More time for soybeans to develop better stand establishment
  • Reduced selection pressure for herbicide resistance to post-emergence herbicides

When selecting a pre-emergence herbicide, choose one with multiple effective sites of action (SOAs) like BroadAxe® XC or Boundary® 6.5 EC. Both have 2 effective SOAs and provide long-lasting early-season weed management. Prefix® herbicide also has 2 effective sites of action, and can be use pre- and early post-emergence.

To manage weeds through the end of the growing season, follow up with a post-emergence herbicide containing multiple effective SOAs. Flexstar® GT 3.5 herbicide delivers proven post-emergence protection when applied before weeds reach 4” tall. Flexstar GT 3.5 is also specifically formulated to fight weeds that are difficult to control with glyphosate alone or are resistant to glyphosate.

For more tips on soybean weed management, visit ResistanceFighter.com.

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