Plan soybean fungicides now
You look at current commodity prices and recheck your crop budget. It’s possible you may need to trim costs. If you still want to make sure your soybeans are protected as much as possible, where do you put those limited dollars you can spend on fungicides?
The key is to know how susceptible different varieties you have planted are to specific diseases, notes Betsy Bower, agronomist with Ceres Solutions, Terre Haute. She would pay most attention to Septoria brown spot, frogeye leaf spot and anthracnose. Remember that fungicides don’t stop all soybean diseases.
• Find out whether your varieties are susceptible to leaf spot, brown spot.
• Check for the presence of disease before spraying.
• Target the application to your most susceptible fields.
“Go back to the person who sold you the soybeans,” says Steve Dlugosz, a crops consultant for Harvestland Co-op in east-central Indiana. Both Bower and Dlugosz are members of the Indiana Certified Crop Advisers group.
“The person who sold you the soybeans should have a more thorough understanding of the strengths and weaknesses of the lineup,” Dlugosz continues.
To spray or not to spray
For Bryan Overstreet, a Purdue University Extension ag educator in Jasper and Pulaski counties, also a CCA, it comes down to brown spot and frogeye leaf spot. “I would see if any of the varieties I planted have resistance to these diseases,” he says. “If they do, I would not spray those varieties.”
Suppose your varieties aren’t resistant. Bower still recommends checking for the presence of disease before spraying. “If disease isn’t present, I would consider protecting soybeans in fields most susceptible to disease development, like seed beans, irrigated beans or soybeans along river bottoms or in low-lying fields. Humidity is often highest in low-lying fields along streams, and that favors disease development.
“I would also consider spraying poorly drained fields, or fields with heavy soils, and fields where soybeans were planted back-to-back. Finally, I would spray fields with excellent yield potential,” Bower says.
This article published in the June, 2010 edition of INDIANA PRAIRIE FARMER.