3 Principles for Effective Weed Management in Soybeans
Early-season weed competition can be devastating to soybean crops. Weeds compete with crops for light, water, nutrients and space, and can slow down planting efforts, getting crops off to a sluggish start.
Weeds will quickly eat into your yield potential and bottom line, and it can happen in a snap. The Iowa State University Extension says weeds can impact yield potential as soon as they begin to take sunlight, water and nutrients from the crop. The Weed Science Society of America puts potential loss in value for soybeans at $16 billion, or 49.5% yield loss, without weed control.
To keep weeds from imposing this kind of damage, it’s important to develop a proactive, strategic approach. Syngenta agronomy service representative Wally West shares 3 principles growers can apply to combat tough-to-manage weeds:
- Use multiple effective sites of action (SOAs). Weed resistance to herbicides is on the rise across the U.S., and growers may not even realize how many tolerant or resistant weeds are in their fields right now. University of Illinois Weed Scientist Pat Tranel recommends at least 5 SOAs per application, citing his co-authored study that found growers following this approach were 83x less likely to have resistance compared to using only 1.5 SOAs per application.
- Choose herbicides with residual activity. According to West, the best time to manage tough weeds is before they even come out of the ground with robust rates of residual herbicides. University of Nebraska-Lincoln research demonstrates that adding a residual herbicide helps keep fields free of yield-robbing weeds longer, ultimately protecting yields and improving resistance management practices.
- Plan a 2-pass approach of overlapping residuals. To maintain clean fields throughout the season, growers should follow their preemergence herbicide with an overlapping application of a post-emergence product, again keeping multiple effective sites of action top of mind.
We recommend an overlapping, preemergence application of Boundary® 6.5 EC, BroadAxe® XC or Prefix® herbicides followed by a post-emergence application of Tavium® Plus VaporGrip® Technology herbicide for season-long management of tough and resistant weeds in soybeans. Combining multiple effective sites of action, Boundary 6.5 EC, BroadAxe XC and Prefix preemergence herbicides deliver broad-spectrum activity and residual management of many troublesome weeds, including problem weeds that are specific to the Upper Midwest. Tavium, the first and only dicamba herbicide premix, can then be applied early post-emergence in dicamba-tolerant soybeans. Tavium delivers both the contact control of dicamba to manage the weeds you see and the residual control of S-metolachlor to help protect against the weeds you don’t see yet. This powerful combination provides 3 weeks longer residual than dicamba alone.
By following these 3 steps, you can stay ahead of tough and resistant weeds and be one step closer to high-yielding soybeans this season.
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