By Darren Hefty

While there has been no new federal or state requirement forcing you to use more than one mode of action as you apply fungicides this year, it is something we strongly recommend. Not only can you help avoid resistance to any single mode of action this way, you may see more yield protection as well. Those two benefits are why the industry is moving toward fungicide premixes with multiple modes of action. In the short term and in the long run, it should be a benefit to your farm’s profits.

In 2011, Brian and I saw firsthand that fungicide resistance to one of our favorite fungicides, Headline, was a reality. We were in Denmark looking at cereal grain production with an agronomist. He said while almost every acre was receiving an application of Headline (which was marketed as Comet in Denmark), they weren’t expecting disease control. Farmers were using it for plant health benefits. Over the years, they had used this active ingredient by itself so much that it just didn’t work anymore preventing diseases. Farmers in the U.S. have found the same thing, most notably with Headline and frogeye leaf spot in the mid-south and on ascochyta in pulse crops in the north.

Is disease resistance to fungicides going to be a problem on your farm this year? Who knows? Whether it is or it isn’t, reducing the odds of that happening should be important to you both from the standpoint of preserving a good fungicide for future use and for preventing disease from developing in your fields this season. Diseases are far less likely to build resistance to two or three different chemical families, as opposed to when one single mode of action is used. That’s the primary reason almost every fungicide manufacturer is pushing premixes and/or blends today. Fortunately, this doesn’t have to cost an arm and a leg.

As many of the most common fungicide active ingredients have gone off-patent, fungicide prices have come way down. Take tebuconazole (think Folicur), for example. It costs only around $1.50 per acre for a full rate versus the $15 it cost 10 years ago. In fact, many of the popular fungicide families contain active ingredients that have gone off-patent and are now available for much less money than they were just before patent expiration. Straight goods are less expensive, and so are products containing multiple modes of action or as we often say, products containing two or three different fungicides.

So how does using multiple modes of action MAKE you money? Since prices have come down, we talk a lot about the cost savings on the front side, but increasing return on investment is really what it’s all about. By using two or three modes of action, you will be able to control more diseases, and in most cases, you will see increased effectiveness at stopping diseases. Ultimately, this should lead to greater yields.

Using multiple modes of action is great for reducing the odds of disease resistance as mentioned earlier. It’s also a way to get the best product for a wide variety of diseases in the same tank, which should improve your disease control and yield. THAT’S why even though there isn’t regulation I’m aware of requiring you to use multiple modes of action when you spray fungicides, you should do it anyway from now on.