Soybean Fungicide Calculator Tool Shows Odds of a Profitable Return

One of the charges for the Iowa Soybean Association On-Farm Network® has always been to help growers learn for themselves how to improve their profits from soybean production.

Working with hundreds of Iowa growers, the On-Farm Network has collected data and analyzed results from more than 300 soybean fungicide replicated strip trials over the past six years.

“We’ve investigated a number of production practices and inputs over the years, with varying results. None of the products growers have studied through the On-Farm Network have shown as definitive results as those from our studies with fungicides,” says Dr. Tracy Blackmer, ISA research director. “From these studies, we can conclude that the odds are high of seeing a yield improvement from a single fungicide application at about the R3 stage. Further, while fungicide product and application costs and the market price for soybeans must be considered, there is also a good chance that a fungicide application will be profitable for most Iowa growers.”

To see whether fungicide use would be profitable in your operation, take a look at the Fungicide Calculator developed this past winter by Dr. Peter Kyveryga, senior research associate for the On-Farm Network, working with Blackmer and Pat Reeg, On-Farm Network technology manager. It can be found at http://www.isafarmnet.com/calc/index.php, or by selecting the Fungicide Calculator link at www.isafarmnet.com.

It’s important to understand that the calculator is based on the 282 studies conducted with Headline® fungicide from 2005 through the 2009 growing season. Trials with other fungicides were conducted, and, while these, too, showed a good probability of yield improvement, the majority of trials analyzed were done using Headline. (BASF, maker of Headline, sponsored some of the On-Farm Network fungicide trials, as did Bayer Ag, maker of Stratego® and Stratego YLD.)

“The calculator was developed after some of the ISA directors asked whether we thought fungicides would be profitable for them,” Blackmer says. “It uses the trial results to calculate a break-even yield increase and the probability of getting that yield increase based on the history of the first five years of our fungicide trials. The expected profit per acre and the probably range of profits per acre are also included in the report generated by the calculator.”

One specific director who requested the calculator was Wayne Fredericks, Osage, Iowa. “This is one more tool that can help growers in making their crop input decisions,” he says. “But it’s also very convincing of the need to consider using a fungicide on soybeans. As growers, we still need to consider other factors, like the probability of fungal diseases developing in our crops. But this calculator shows that we can learn a lot from a straight income-cost analysis when we can use data from multiple years and trials from all over the state.”

To use the fungicide calculator, insert your expected soybean price and the costs associated with the use of the fungicide (product price and application cost, plus any other fees charged).

With these two numbers, the calculator produces a four-part report like the one shown here.

Questions about the calculator, its use, or about the On-Farm Network in general can be sent to info@isafarmnet.com.