Modern corn and soybean fungicides such as Miravis Neo excel beyond disease control into premium plant-health benefits.
Your operation risks being left behind if you aren’t incorporating a fungicide into your corn and soybean management programs.
A plant-health fungicide “helps with your peace of mind no matter what kind of weather you’re going to get — whether it turns out wet or dry, there’s value there,” said Don Boehm, a grower in Northwest Ohio. “There’s never been a year when I didn’t think the fungicide paid for itself.”
Fungicides are a vital tool to help American farmers combat foliar disease pathogens in their corn and soybean fields. Their application — in conjunction with thoughtful timing, environmental conditions, and fungal activity — contributes to their effectiveness at helping plants achieve optimal grain fill.
The cost of bypassing a fungicide is too big to ignore. Last year, disease reduced corn yield by about 6% across the U.S., resulting in an estimated loss of almost 950 million bushels. In soybeans, the loss that year was estimated at 5.4%, totaling 250.9 million bushels.
There are numerous yield-limiting diseases that can impact American fields. In plants, fungal diseases are more prominent than viral or bacterial diseases, which are more commonly associated with humans and animals.
Fungal diseases can be difficult to address once they appear in the plant, so the best modern fungicidal chemistries include a preventive element.
Boehm’s farm usually faces at least some disease pressure — notably tar spot in recent years, but Northern corn leaf blight, gray leaf spot and rust have also been issues. The longtime Syngenta customer leans on a fungicide to help him protect his yield not only by reducing disease stress, but also by improving nutrient and water usage in the plant and its standability at harvest.
He said spraying Miravis® Neo fungicide has helped him protect as much as 25 to 30 bu/A of corn yield in some years, especially when tar spot — caused by the fungus known as Phyllachora maydis and identifiable by small, circular tar-like spots present on corn leaves, stalks, and husks — tries to show up later in the season.
Across U.S. soybean fields, frogeye leaf spot, white mold, and Septoria brown spot are among the diseases at the front of growers’ minds.
Fungicides in soybeans are normally sprayed during early reproductive stages (typically R2 to R4) when the plant starts to focus energy into pod fill and the most important leaves for contributing to that are exposed and best protected by the fungicide application. In corn, spraying is usually during late vegetative to early reproductive stages, when plant transpiration begins to take off and the important ear leaf becomes exposed.
Miravis Neo has robust residual activity across a variety of environmental conditions and does well to protect corn and soybean crops long into the growing season.
“Margins on the farm aren’t great, so we need every bushel we can get,” Boehm explained. “I’ve got friends and neighbors who are looking to cut, and they want to save themselves to prosperity, but you can’t do that through sacrificing your fungicide use. I work to protect the yield potential that’s there.”
Fungicides are most effective when used preventively, because even though these types of products can stop an active infection, they are unable to repair any damage to the corn or soybean plant — and thus regain any yield loss — that has already occurred.
Even as more corn hybrids become available in the marketplace, disease continues to be a threat to growers’ livelihoods. Tyler Harp, technical product lead for row crop fungicides at Syngenta, explained that while new hybrids have been developed that are capable of pushing higher yields, in some cases they may also be more susceptible to certain diseases. Over time, some diseases can become more aggressive and widespread, potentially threatening more yield potential than in the past.
This situation can become compounded on farms that go corn-on-corn across seasons, with some diseases proving hardy enough to survive winters in infested crop residue.
At Syngenta, “We like to use the term ‘cleaner and greener’ ” with our premium fungicides, Harp noted. “Cleaner refers to that important disease control, but of course, that’s table stakes for fungicides today. Greener is the differentiating factor of a plant-health fungicide, and it refers to the plant-health benefits. It essentially means not only are you getting some fungicide activity, but you’re also getting some stress mitigation.”
Plants can be affected by two types of stress: biotic stress, which is caused from biotic organisms in fungal diseases; and abiotic stress, which is caused from environmental stresses such as heat or drought. It’s estimated that crop stress can steal up to 50% of potential yield.
With a plant-health fungicide like Miravis Neo, “You’re preserving yield in the presence of biotic and/or abiotic stress,” Harp noted. “Our data shows that, even in cases where you may not get a lot of disease pressure but you have a lot of heat and drought stress, you’re still going to be able to preserve yield with Miravis Neo. It works well to prevent yield limitations because of stress.”
Miravis Neo harnesses all three major modes of action. There’s the triazole chemistry, which has the demethylation inhibitor (DMI) mode of action and is built to stop any active disease that may have occurred before the application. Then there are the other two: ADEPIDYN® technology, which is a carboxamide chemistry with a succinate dehydrogenase inhibitor (SDHI) mode of action, and the strobilurin chemistry that uses the quinone outside inhibitor (QoI) mode of action. Both are more preventive in nature, making them especially effective against early infection, protecting the plant for the long term, and inhibiting further disease spread. More importantly, their combined protection from crop stress preserves yield potential more than any other option on the market.
With these three powerhouses in one product, growers applying Miravis Neo in 2024 saw an average of 5 bu/A yield increase in the soybean crop compared with untreated acreage1 and an average 16 bu/A yield increase in corn compared with untreated2 — and Harp noted that 80% of the time, the fungicide application was profitable.
That means only once every five years would you just break even or have a small loss.
“But here’s the thing,” Harp said, “no matter how we cut the data, this is always what it tells us: One of those four years is going to be a hit-it-out-of-the-park 20 bushel or more return in corn and 10 bushel or more in soybean. And that would be enough to pay for all five years of your fungicide.”
It’s the kind of year Boehm described having using Miravis Neo, and other growers report similarly positive results.
“We had the best yields we have ever had this year,” said Lisa Peterson, a grower from Iowa who used Miravis Neo in 2024. “I feel sorry for those that gave up on their crops and did not finish strong with a fungicide.”
Class is in Session — See more articles in this fungicide series here:
- Fungicide 201 — The Science Behind the Performance: The science behind modern advanced fungicides
This article was funded by and published on behalf of Syngenta. Explore Boost Your Bushels to learn more about Miravis Neo. Visit this page to find a Syngenta Crop Protection Specialist near you.
Ryan Tipps is the founder and managing editor of AGDAILY. The Indiana native has a master’s degree in Agriculture and Life Sciences from Virginia Tech and has covered the food and farming industries at the state and national levels since 2011.
