Would a New MOA Be the Next Step in Weed Control?
We often tout how complex the field is for row crop production—the rapid pace of seed development, the delicate balance of a perfect fertilizer package, the hi-tech computer system in the newest planter set up. And it’s true.
Every season brings brand new opportunities to adopt the latest technologies and practices, each one developing and coming to market faster than the one before. But a closer look at the current herbicide chemistries and product line up might make you question how true a statement that is.
On first glance, it seems all the “newest” herbicides are just combinations of existing herbicides, new formulations on old chemistry or perhaps the same herbicides at different concentrations. These new products may have a shiny new label, or be slightly more convenient to use, but to call them truly new? That could be a stretch.
One of the most significant characteristics of any herbicide is its Mode of Action. MOA explains how the herbicide interacts with the plant, from the moment the product enters the plant to the time the targeted plant dies. And it’s been a while since we’ve seen a truly new MOA.
Developing new herbicides is an expensive and lengthy process. Many new chemical compounds are tested and screened every year by chemical companies (and the number of competitors on that list decreases after each merger and acquisition). Once a compound shows some favorable activity, it is tested extensively to determine its positive, and negative, impacts. It can take 6 to 12 years from the development or discovery of the formulation (active ingredients combined with inactive ingredients) to advance it to market as a new product. Government regulations also play a role in the timeline. This process may seem excessive; however, thorough testing and careful labeling can help avoid serious problems with these products, particularly with crop and applicator/handler safety.
So, what would it take to see a new MOA?
A new chemistry would need to:
have low handling and application volume
help control resistant weed species
be environmentally safe
be useful multiple crops or rotations, and have no extensive carry over issues
present no or low health risk to handlers/ applicators
But new chemical herbicides aren’t necessarily the answer. There’s always new research being done in the area of weed control, from university extension to private companies. While some companies are working on developing new chemically based herbicides, others are more focused on opportunities for biological control of weeds.
The secret to successful weed control isn’t new products alone—it’s also better practices:
It’s following label recommendations closely: Using the right rates in the right fields to kill the right weeds. Most weed resistance is attributed to poor application (i.e. using too much or too little of a product in the same field for too long of a time period.)
It’s incorporating multiple MOAs: Using multiple modes of action to get the most comprehensive control, and just as importantly, to prevent resistance to any particular mode of action.
It’s utilizing more conventional tools when necessary: Tillage can assist with weed control when necessary. No weeds are resistant to proper tillage.
It's an overall, integrated approach to herbicide resistance management that takes crop rotation, tillage system, cover crops, fertility and chemistry into account.
Always read and follow label use instructions.