There is a lot of speculation about a herbicide shortage for the 2022 growing season, which will impact weed management decisions starting with fall applications.
Purdue Weed Science Specialists Bill Johnson, Marcelo Zimmer, and Bryan Young shared the following information that should be considered ahead of the 2022 growing season across the midwest.
The two main active ingredients that we’re hearing about right now are glyphosate (Roundup, others) and glufosinate (Liberty, others), both associated with an increase in cost. There will likely be limited supplies of other pesticide active ingredients as well, but in the short term, a shortage of these two active ingredients poses some major challenges for corn and soybean production.
As you search for alternatives to these two herbicides you may have already determined that weed control guides produced by University Extension and Industry will become your most important tool for planning your herbicide purchases for many years to come.
First, what is causing the shortage?
There are several different factors which are impacting this issue. In no particular order, the reasons for the herbicide shortage include a decline in number of laborers to unload tanker ships at gulf ports, lack of truck transportation from the ports to get the ingredients to U.S. formulation plants or formulated products to the retailers, reduced supplies of some of the inert ingredients of the formulation, shortages of materials to make containers and packaging, and Hurricane Ida that damaged a glyphosate production plant in Luling, Louisiana.
Regardless of the cause, it is also important to consider herbicide costs. We are hearing that glyphosate prices will be in excess of $80/gallon. So, even if there is not a shortage, you should plan your weed control strategies for the next growing season to accommodate a limited availability because of supply or price of these two active ingredients.
It is important to point out that the demand for glyphosate will be considerably less in a conventional till system then in a no-till system. Glyphosate is arguably the most important herbicide that facilitates no-till crop production. It’s even more important in systems where cover crops are used and need to be terminated before corn or soybean planting.
Therefore, one simple way to reduce reliance on glyphosate is to simply go back to using tillage for fall and early spring weed control. This practice will be very effective for controlling the weeds emerged at the time of tillage, but some farm operations may not be set up for the extra equipment, labor, and fuel needed to do this on a widespread basis. In addition, replacing burndown herbicides with tillage threatens soil conservation practices. Glufosinate demand, on the other hand, will not be impacted as much by choice of tillage system since we don’t use glufosinate in our fall or spring burndown application; however, we mostly use glufosinate postemergence in soybeans after the crop and summer annual weeds have emerged.
If you’re not interested in returning to widespread use of tillage, keep in mind that you are looking for ways to control winter annual weeds before planting and control grass weeds with other herbicides to decrease reliance on glyphosate for postemergence grass weed control. Secondly, regardless of tillage system, you want to build a solid residual program as the backbone of your weed control strategy to reduce reliance on using glyphosate postemergence in the crops.
Target using “regular” rates of glyphosate to stretch supply. Instead of using 32 or 44 oz/acre of a Roundup brand product, consider using the standard rate on the label such as 22 oz/acre for Roundup PowerMax .
Identify glyphosate or glufosinate premixes that may be in greater supply or at lower relative costs compared to solo glyphosate and glufosinate products.
Failure is not an option for herbicide applications. Make sure you optimize your herbicide applications using the best methods (GPA, spray nozzles, etc.), adjuvants, and minimal weed size for foliar applications.
Cultivate if needed and/or possible.
Hand weed escapes prior to the weeds setting seed.
Elysia Rodgers, ANR Educator, Purdue University Cooperative Extension Service, DeKalb County. The Purdue University Cooperative Extension Service is an Affirmative Action, Equal Opportunity institution.