• By Larry Steckel •
In most cases applicators were able to get what they needed. However, this spring retailers were often able to fill shortages by accessing carryover from 2020. I have been told there will be no carryover herbicides to fill holes in 2022 so the probability of herbicides not being available is much more likely.
The two herbicides everyone is pointing to that we will most likely run short of in Tennessee are glyphosate and glufosinate. Several retailers have said they are only being allocated at best 80% of what glyphosate and glufosinate they sold in 2021.
Moreover, delivery of those herbicides may not occur until July in some cases. As such, here are some thoughts on how to effectively stretch the 2022 glyphosate and glufosinate supply.
Not just any glyphosate will do
Please remember that not just any glyphosate can be tankmixed with XtendiMax or Engenia, only the K-salt glyphosates listed on the XtendiMax or Engenia tankmix websites may be used. As such, if you have other glyphosate formulations (i.e. DMA or IPA salts of glyphosate), be sure to use them for weed control in burndowns or in corn, etc.
This will save the approved K-salt glyphosate formulations to be tankmixed with XtendiMax and Engenia post in Xtend crops.
Also, be flexible about how to access glyphosate in 2022. There are a number of premixes that contain glyphosate and would be an option to use that herbicide. Herbicides like Acuron GT, Enlist Duo, Flexstar GT, Halex GT, Sequence or maybe even some Extreme that might be on the back shelf would all be a way to acquire glyphosate.
A good substitute for glyphosate
Finally, if glyphosate cannot be found, then a good substitute would be clethodim for grasses. Remember if ryegrass, goosegrass, junglerice, barnyardgrass or fall panicum are the targets then use at least 16 oz/A of a 2 lb clethodim to get the best results.
Unfortunately, there will not be a good herbicide substitute for glufosinate. One has to make every gallon count. A way to do that is to apply it when it has the best chance to work well.
This would include it being applied on hot days with highs well into the 80s. Also apply it between 9 a.m. and 4 p.m. to get the most consistent weed control. If applying to Enlist crops, be sure to tankmix it with Enlist One.
In Extend crops, apply it no later than 10 days after a dicamba application to have the best chance of killing the Palmer that is dicamba resistant. Finally, Cheetah Max (glufosinate + fomesafen) is the only premix that contains glufosinate that comes to mind as a possible option to access glufosinate.
Dr. Larry Steckel is a University of Tennessee Extension weed specialist. He may be reached at email@example.com