On Fungicide, Again

ReachOut: On Fungicide, Again from Central Valley Ag on Vimeo.

by Mike Zwingman

by Mike Zwingman

There’s a comedian who says that there are two levels in national security: Get Helmet and Put On Helmet. Well, friends, two weeks ago, when I last wrote about fungicide: that was the call to get your helmet. Today, I’m writing about fungicide again: now it’s time to put that helmet on.

Two weeks ago, I wrote about fungicide kind of on a hunch. Today, I’ve seen enough evidence to write about fungicide as a response to an actual and serious problem. This problem is not isolated. It is not coincidence. It is not random. It is very, very real, and possibly in your fields.

As I said in my original article, making the decision to apply fungicide can be a tough one because it’s a hefty investment. Fortunately, research over the last few years (seven, actually) suggests that regardless of the cost of an application, it brings a return on investment. A fungicide application at tassel has averaged an 8.25 bushel per acre increase in yield over the last seven years in our area.

This number isn’t quite the whole story though, of course. If we look only at the years with low disease pressure, the average increase spurred by a fungicide application drops to 7 bushels per acre. Alternately, if we look only at the years with high pressure, the average increase rockets up to a 12.6 bushels per acre.


Let me put these numbers in the context of today’s economic climate. At the time of this writing, corn is selling at $3.84. That dollar number would make for a $31 cash return for using fungicide based on a 8.25 bushel per acre increase. That’s a 1.3 to 1 return on investment. Based on the higher 12.6 increase, it would make for a $48.35 cash return—or a 2.1 to 1 return on investment. Even the lowest increase—7 bushels per acre—is enough that you would essentially break even.

But I can quote you numbers all day long. The real power here comes from leveraging the information behind the numbers into sound decision making.

Two weeks ago, I asked you to go out into your fields and see, feel, touch. I asked you to scout and I asked you to gather some key information on your hybrids. Today, I’m asking you to do something with that intell.

Now is the time to put it all together, friends. Chance favors the prepared mind. If the results of your scouting suggest to you that disease is present or very possible in your fields and your hybrids don’t have stellar resistance, a fungicide application at tassel would probably have a significant impact on your yield. The bushels per acre you might gain would likely be nearer 12.6 than 8.25 or 7. Given the high disease pressure that is building this season, even those of you finding yourselves in less-vulnerable positions could stand to gain from an application: your increase might be nearer the 8.25 mark, but even that increase is enough to put a little extra cash in your pockets at harvest.

Blue-Box-e1409667504172History supports your decision to make a fungicide application at tassel, particularly if you see evidence that disease is present in your fields, and particularly if your hybrids have low resistance. You know that our profession offers few, if any, guarantees, so I can’t say that you can’t fail with a fungicide application this year. I can say though that we’ve been counting the cards long enough and well enough to say that the time is nigh to make a bet.