By Brad Philipp, Field Sales Agronomist – After you have made hybrid and genetics decisions on your fields and ordered the bulk of your fertilizer for next year, what’s next? When you still have prepay dollars to invest, the next most important decision is your pre-emerge for both corn and beans for next spring. You still get a big bang for your buck booking chemicals early. Let’s not be misguided; the decision here is not at all about price, it’s about performance. As we have shown in previous articles and posters, we recommend a 3 pronged approach: 1) Fall burndown and if that cannot get applied, it may become an early spring burndown as winter annuals like marestail are crucial to control – especially ahead of beans. 2) At planting, use a residual herbicide/burndown program to clean up any winter annuals and to provide waterhemp, grass and nightshade control from planting through that first, in season treatment. 3) In-crop glyphosate + a residual – again for waterhemp. Sounds like a lot and, no doubt, may be more than you needed in the past. Unfortunately, we are dealing with a different set of glyphosate resistant weeds than in the past and not just one additive can cover BOTH winter annual weeds and the summer annuals like waterhemp and ragweeds.
Let’s look much closer at step number 2) At planting residual/burndown. We sometimes call this the “afterburner” because it might be a burndown that did not get done because of weather and the beans are in the ground but not up yet. In this case, or even where the burndown may not have cleaned up all of the marestail, we choose a product called Verdict™ from BASF. Verdict™ is a premix of Sharpen® and Outlook®. Outlook® is the grass and small broadleaf residual we need for waterhemp and foxtails, among many other weeds. Sharpen® is needed in this mix since it is the only product out there to control stray marestail among many other broadleaves at planting BEFORE beans emerge. Once the beans are up, there are few, if any, options to control marestail. So the combo in Verdict™ becomes a valuable selection for us. To enhance this further, we recommend an addition of 8 to 10 ounces of Outlook® to stretch the waterhemp control and give your glyphosate a fighting chance to win the battle in season. Or to simplify your choices, use the premix product from BASF called OpTill®PRO. This is a combination of Sharpen®, Outlook® and Pursuit®. This is a convenient pre-pack that is ready to go. OpTill®PRO is a premium premix that has the broadest spectrum and most effective control of all weeds.
Even if waterhemp does not escape the Verdict® application, we will recommend the addition of Outlook® or Warrant™ to the in-crop glyphosate treatment for residual control through canopy. We found out that if waterhemp escapes earlier treatments, the only option we have is to add Cobra® to the glyphosate for a less than desirable control. Along with crop response and other side effects, Cobra® is only a rescue attempt, as waterhemp must be controlled before it even breaks the surface. We have found that, without the residuals, way too much waterhemp made it to and through the combine this past harvest; so we must double up our efforts to control this expanding glyphosate resistant species and all its relatives – especially its cousin, Palmer Amaranth. Palmer Amaranth is quickly becoming known as the new resistant weed in town.
These are just a few ideas on how to control this resistance phenomenon. I know this means that gone are the days of the 2 shot, $10/A. glyphosate do-it-all. It will cost more, but it will do more to increase yields and keep the weeds from entering the combine at harvest. Just because we are focusing on weed control in beans does not mean that weeds in corn are easy and not a problem. Verdict® is also a pre-emerge/burndown option labeled for corn as well. Verdict® can increase profits for both corn and beans by controlling weeds early and by preventing ghyphosate resistant weeds from robbing yield potential.