Managing Weeds in NON-GMO Crops

Between the Fencerows

Making the transition back has been a chemistry lesson of sorts

Published on: June 26, 2013

In the last few years, I've read more herbicide labels than I would care to admit.  Making the transition back to NON-GMO crops has caused me to re-learn chemistry and combinations.

Managing corn is by far simpler.  The newer grass herbicides for post applications, such as Laudis, Impact and Armezon, are not harsh.  It has changed from the past when a post-grass application was the last thing you wanted to do, especially if the corn was getting a little big. 

Pre-emerge and early post-emerge products like Lumax and Corvus have also been doing a good job.  They seem to have more activity on giant ragweed, lambs quarter, and burr cucumber.  The biggest challenge we had this year has been on farms where we used counter insecticide to help on the nematodes.  Counter, an organophosphate, is not compatible with some of the chemistry listed above.

Now to the soybeans. Well, not much has changed in 20 years.  We usually use Canopy/Boundary or Optill PRO down.  Those products are comparable to each other, and do a pretty decent job.  The tricky part is managing the escapes such as poke berry, giant ragweed, hemp dog bane, and lambs quarter.  If you spray the post pass too early, you're at a higher risk of more weeds coming through.  However, if you wait too long – or it rains for 3 weeks – the weeds will be stagnant for a week or two after treatment, but then start growing again. 

We use Flexstar and a grass herbicide for our in-season application.  You also have to be careful not to spray the Flexstar too far into the summer, as there are carryover concerns going into corn. 

When spraying later in the season, I have used Bassagran, Blazer, 2,4D-B and Synchrony, in different combinations; I'm still trying to figure out what works best.  There are times we just have to get some kids and go after a few trouble spots with a weed hook or hoe. 

But the good thing about using 20-year-old chemistry is that much of it can be found in a generic at a significant savings to the branded product.

What are some products you use? Have you found anything that works the best? Weigh in below.