Snow blanketed Doug Rupp’s fields on a frosty morning this past December, but Rupp paid no attention to the cold. He’s already focused on this summer and his plans to apply fungicides to his corn crop and make money in the process.
While company, university and independent agronomists debate whether a proactive fungicide application to corn can provide a positive yield response, Rupp says his personal experience proves it can.
"I plan for these applications six to nine months in advance," says Rupp, who farms 2,000 acres of corn and soybeans near Stryker, Ohio. "It isn’t something you can just run out and do and make pay."
Part of Rupp’s planning process is based on the type of hybrids he grows and expected commodity prices. The other key factor is negotiating the best deal for the products and applications.
Focusing on the big picture and individual details has helped Rupp garner a payoff from corn fungicides about four out of every five years.
Rupp likes to grow racehorse-type corn hybrids that offer high yield potential but typically have few defensive traits and benefit from fungicide application.
Rupp purchases fungicides in bulk and out-of-season. By buying early, he cuts his retail product price tag by about 50%. He estimates he paid $10.80 per acre in 2010 for a combined, full rate of a strobilurin-based fungicide and an insecticide. The insecticide is about $2 of that cost.
Playing the Odds. Rupp makes the first application with his ground rig when the corn crop is about 16" tall. He then makes an aerial application when the corn is tasseling.
He acknowledges that the payoff from the two applications varies.
"In a year when fungus is bad, you might have a 15 bu. to 20 bu. yield advantage, while it may only be 2 bu. or 3 bu. in a marginal year," he says. "If a farmer tries this in the wrong year and gets burned, it will take a lot of persuasion to get him to try it again. You have to use some common sense."
Clarke McGrath, Iowa State University Extension field agronomist, says in a recent blog: "The odds of getting a yield response to fungicide applications go up under these conditions: growing corn-on-corn; planting varieties susceptible to diseases such as gray leaf spot, rusts and anthracnose; planting no-till corn; planting corn late; disease activity around tasselling time; and weather that favors disease development."
Missy Bauer, Farm Journal Associate Field Agronomist and one of three advisers working with Rupp as part of the Ultimate Farm Quest project, says the trials she conducted in 2010 prove success isn’t always a slam dunk every time fungicides are applied to corn. In one fungicide study on 27 different corn hybrids under irrigation, she saw an overall 11.4 bu. per acre yield advantage.
However, Bauer says, the comprehensive yield results varied wildly by hybrid—from a 9.5 bu. per acre to a 36 bu. per acre yield advantage. "That was the same plot in the same field," she notes.
Her perspective: The relationship between hybrid, environmental conditions, agronomic factors and management play a role in how hybrids respond to fungicide application.
- February 2011