Waiting until regions are free of Hessian flies will give growers a much better chance to get a good crop of wheat going and will avoid problems with crop diseases such as barley yellow dwarf virus, says Andy Michel, an Ohio State University Extension pest expert.
The optimal time to plant winter wheat is within 10 days after the fly-free-safe date for Hessian flies, which in northern Ohio this year is Sept. 22-30 and in southern Ohio is Oct. 1-5, said Michel, who also has an appointment with the Ohio Agricultural Research and Development Center.
OSU Extension and OARDC are the statewide outreach and research arms, respectively, of the College of Food, Agricultural, and Environmental Sciences at The Ohio State University.
Waiting until the Hessian fly-free date is also a benefit for growers who plant wheat and rye and other plants as cover crops to promote soil health, Michel said. The goal is to avoid planting before adult Hessian flies die to prevent them from laying eggs in wheat fields.
The Hessian fly date ensures that wheat growers are less likely to experience infestation and crop damage from Hessian flies. Hessian fly maggots damage wheat crops by feeding on the crown and base of the wheat leaf.
“In wheat planted too early, the eggs can hatch and stunt or kill the wheat plants,” he said. “Growers who are planting wheat as a cover crop instead of a cash crop still need to heed the fly-free dates because the fields could act as a breeding ground for Hessian flies to start building populations.”
Disease prevention is another benefit of planting wheat after the fly-free dates, Michel said. Diseases including barley yellow dwarf virus are transmitted by aphids, minute bugs that feed by sucking sap from plants. Barley yellow dwarf virus tends to be most severe when transmission occurs in fall, he said.
“Ohio State research on planting dates found that barley yellow dwarf virus problems and yield loss associated with the disease are higher when wheat is planted before the fly-free date,” Michel said. “Following the fly-free planting guidelines also can help growers avoid problems with other wheat diseases, such as leaf rust and Stagonospora blotch
The Hessian fly safe date for each county can be found here.