By Darren Hefty

If you are raising soybeans, chances are very high that you are fighting broadleaf weeds that are resistant to Roundup on your farm. So how are you going to stop them from going to seed this year?  What’s your plan to eliminate the weeds that are robbing 5, 10, 20, or even more bushels per acre?

Here are seven steps that you can take.  At first glance, you will probably say that for three or four of them, you have ZERO interest in doing on your farm.  For that reason, I start with the ones that you just can’t leave out of your crop plan this year.  I’ll explain.

  1. Three Pre-Emerge Residual Sites of Action.  Any trait package can work in moderate weed pressure fields if you start with the three pre’s.  We expect to control 99 percent of the small-seeded broadleaf weeds by putting down a yellow (Treflan, Sonalan, or Prowl), plus adding a PPO (Valor or Authority), and also using metribuzin (Tricor, Glory, or others).
  2. New Traits.  Some would put this first, but I believe it’s a secondary decision to using the correct pre-emerge residual strategy.  That said, a herbicide-tolerant trait or stack of traits is a great way to add options to your weed control portfolio.  LibertyLink has been growing in popularity and performing well.

    If you don’t believe that, then answer this question:  Why are all the trait providers scrambling to add LibertyLink to their newest traits?
    Answer: It’s an effective weed control option.  With approval of the dicamba-tolerant Xtend trait expected very soon, you may have access to a limited number of Roundup Ready 2 Xtend soybeans for 2016.  While it should be a great trait that provides excellent weed control options for you, there won’t be enough seed for everyone to plant their whole farms to it in 2016.

    Those are the best two options for SUPER weed control.  If you skip those two steps, don’t count on these next five to be the total answer to perfect weed control AND maximum yield and profitability.  However, they are your best options once the soybeans are planted and have emerged.

  3. Post-Emerge Residual.  There are a number of products labeled and currently being used post-emerge that can extend your residual weed control.  Outlook, Dual, Warrant, and Anthem are the best choices.  These products aren’t great on broadleaves, especially at the reduced rates you’ll use post-emerge in soybeans compared to corn.  However, they will give you some weed control help provided they get moisture to activate.  None of these options provide burndown of emerged weeds.
  4. Properly Timing Post-Emerge Applications.  None of the post-emerge herbicides like Flexstar, Cadet, or Cobra hold a candle to what Roundup used to do.  Remember when we could spray a 12-inch tall weed and expect to control it 100 percent?  Even a 24-inch pigweed was not out of reach for a strong rate of Roundup.  With any post-emerge herbicide today, the weeds should be four inches tall or smaller.  If you get the timing right, the post-emerge products aren’t too bad.
  5. Using the Best Spray Adjuvants.  It does make a difference to use the best and strongest spray additives.  Personally, I like what MegaGro adds to weed control in a tankmix with Roundup and Flexstar.  Choosing a crop oil over a non-ionic surfactant makes a huge difference with something like Cobra.  Even picking ammonium sulfate versus some of the other water-conditioning agents can be a big deal.  Of course, this all depends on what you’re mixing, what the weather is like, and what your timing is.  Talk to a seasoned agronomist to fine-tune this.
  6. Cultivation.  Not many farmers have a desire to cultivate these days, but it might be your best bet for killing weeds in between the rows if you have a large number of weed escapes.
  7. Hand Weeding.  Whether it means hiring a crew or doing it yourself, pulling or chopping weeds is still an effective means of control.

Conclusion: Use the three pre-emerge herbicide strategy (and ask your herbicide dealer about programs to get the costs down to less than a post-emerge shot of Cobra).  Then, utilize herbicide-resistant traits to give yourself another effective post-emerge option to stop the so-called SUPER weeds.