“If two is good, three is better, and the newest is even better yet!”
That’s the mindset we need when it comes to fungicide modes of action (MOAs). As crop prices soften, it’s tempting to reach for the cheapest option on the shelf. But when disease pressure is high—like it is now with all the recent rain and humidity—cutting corners can cost you more than you save. We all know fungicide helps with standability, and no one likes to combine downed corn. That’s where saving time can be a significant factor in a fungicide decision.
Why Multiple Modes of Action Matter
Fungicides with multiple MOAs are like a multi-tool for disease control. They attack fungal diseases from different angles, making it more difficult for the diseases to adapt and survive. The newest MOAs are especially effective because diseases haven’t had the exposure to them like many of the fungicides introduced 15-plus years ago. This means they are more likely to work.
Disease Resistance Moves Faster Than Weed Resistance
Fungal diseases reproduce through spores—and lots of them. While a weed might drop thousands of seeds, a single plant disease can release millions of spores. That’s why resistance builds faster in diseases than in weeds, and why relying on a single-mode generic fungicide is risky. This is also why it’s important to spray at the right time, before disease pressure becomes heavy.
Timing Is Everything
It’s very common to hear people talk about the preventative component of a fungicide or the curative component of a fungicide. While these aren’t agronomically scientific terms, we’re going to use them here since they are standard terms.
Preventative fungicides stop spores from germinating.
Curative fungicides stop fungal cell respiration in already infected tissue.
This is why we emphasize the importance of applying a fungicide to corn at the tassel stage. Years of data suggest this is our most consistent ROI. Especially if your fungicide has a Group 7 MOA, getting it out early can provide weeks of protection and help carry the crop through to and beyond R4. R4 is when kernel fill is happening—or the dough stage. There is still a lot of yield to be made from R4 to R6, but the weather typically changes by then, and disease pressure is expected to lighten. This is why the newest 3-MOA fungicide option is always best.
Cheap Now, Costly Later
A generic, single-mode fungicide might seem like a cheaper option right now, but it could:
- Wear off too soon
- Leave you vulnerable to resistance
- Fail to protect yield during critical stages
That’s a gamble that doesn’t pay off when disease pressure is high.
Bottom line: When a farmer asks why they should invest in a premium fungicide, remind them that it’s not just about cost—it’s about timing, protection, and yield. The right product, applied at the right time, can make all the difference.