Certain herbicides — particularly glyphosate and glufosinate, the active ingredients of Roundup and Liberty, respectively — may be hard to find this year. Bill Johnson emphasizes that letting weed escapes grow longer with soybeans isn’t the answer to dealing with the herbicide crisis and weeds in 2022.

“You need to watch weed size and spray while weeds are small,” says Johnson, Purdue University Extension weed control specialist. “If you only have limited supplies of glyphosate and glufosinate, you will need to consider alternatives and save those products for where you need them most.”

Here are two examples illustrating adjustments that may be necessary this year.

Grass is coming

The grass isn’t overly thick in photo featured above, but Johnson says if this is your field this year, you should spray now. The grass is taller than it looks, compared to the size that most postemergence herbicides can control easily, he says.

Deciding which herbicides to apply starts with knowing which herbicide-tolerant traits these soybeans possess. If they’re Xtend beans, glyphosate and clethodim are options. For Xtendflex, Liberty also becomes an option. For Enlist beans, glyphosate, Enlist Duo, clethodim and Liberty are possibilities.

Even if you have these traits, you may want to consider grass herbicides, such as Select and Assure, Johnson notes. Because the grass is relatively tall and since there can be antagonism with grass herbicides and dicamba or Enlist, he suggests going with the upper end of labeled rates of the grass herbicides.

See the broadleaves?

Weeds also don’t appear thick in the photo below. However, once again, Johnson would spray now, not wait for more weeds to emerge.

“Spray them now!” he insists. “You’ve got giant ragweed and lambsquarter plants in the mix.”

Johnson’s best recommendation for this field would be applying the full labeled rate of Enlist plus glyphosate or Liberty to take out grasses that are present if the soybeans are E3 and tolerant to 2,4-D choline in Enlist. If the soybeans have the Xtendflex trait, he would go with an Xtend dicamba product, plus glyphosate or Liberty, which is glufosinate. For soybeans that are Xtend but not Xtendflex, Liberty is not an option.