Published on Monday, May 2, 2022
This should come as a surprise to no one, but the herbicides glyphosate and glufosinate are in limited supply and have received price increases for 2022. The purpose of this article is to help you navigate this volatile market while still controlling troublesome weeds in your soybean fields. The focus will be on controlling pigweed species (waterhemp and Palmer amaranth), but the information is applicable to most of our weed spectrum.
The best way to control weeds is to keep them from emerging. This statement is true regardless of the inventory or price status of glyphosate and glufosinate. While the use of pre-emergent residual herbicides is widespread and growing, there is always room for improvement. The reason residual herbicides work, where other postemergent options have failed, is that there are very few weed populations that are resistant to effective pre-emerge modes of action (MOA). It’s why Beck’s continues to evaluate the advantages of putting the Power in the Pre® for a successful weed control program.
The same cannot be said about our POST options. When you look back at the last 25 years, the most prevalent MOAs for controlling weeds in soybeans were ALS inhibitors and PPO inhibitors. Throughout the Midwest, basically every field has some waterhemp that is resistant to ALS and PPO inhibitors. This statement isn’t meant to be a scare tactic; it’s a motivational tool to promote pre-emerge residual products. Even in populations that are resistant to ALS and PPO applied post-emergence, we see excellent control with those products applied prior to emergence.
There are many options and brands that are effective on a wide range of weed species. The active ingredients that provide excellent pre-emergent control include (but are not limited to): metribuzin, sulfentrazone, flumioxazin, pyroxasulfone, metolachlor, acetochlor, and dimethenamid. Your options are more limited from a post-emergence standpoint, but dicamba, 2,4-D, glufosinate, glyphosate, fomesafen, acifluorfen, and lactofen are all viable, provided your weed population is not resistant. Due to the genetic diversity of pigweeds, rarely is an entire field population resistant to a specific herbicide. Due to this genetic variance, the use of multiple modes of action will generally be successful. Timing is a major factor in weed control as well. Regardless of the herbicide being used, the smaller a weed is (less than 6 in.), the easier it will be to kill.
With that said, it is unrealistic to believe glyphosate and glufosinate should not be considered as options for 2022. While supply is limited, there is supply. Anecdotally, I’ve been hearing that customers will be able to buy as many gallons of glufosinate as they did last year. Also, retailers have been fairly effective at sourcing various generic formulations of glyphosate. So, this isn’t a “the sky is falling” scenario. It’s still a great opportunity to utilize existing herbicides to not only meet but exceed previous weed-control standards and, at the same time, likely save money.
Below, I have included some options for replacement products that could help reduce the gallons of glufosinate and glyphosate you’ll need for 2022:
o Glufosinate (broadleaves) – dicamba, 2,4-D, acifluorfen, lactofen, and fomesafen
o Glyphosate (grasses) – clethodim, sethoxydim, fluazifop, and imazethapyr
At Beck’s, we’ve put a lot of time and effort into producing an annual Soybean Herbicide Recommendation Guide to help you navigate all of your options, no matter the soybean trait platform you are planting. There is a lot of valuable information in the guide, including herbicide programs for all traits and weed pressure scenarios, weed species highlights, herbicide injury symptomology, and much more.
Remember, it’s easier to control weeds before they emerge, but if they do emerge, earlier applications are always better. Scout early and often and have a plan in place. As always, make sure to read and follow the label of any herbicide before making an application.
Thanks for your time, and have a safe and successful 2022!
Author: Alex Long
Categories: CropTalk, 2022
Tags: soybeans, weed control, herbicides, weed management