Proper combine setup blows away scab-infected wheat
A few adjustments to machinery can make a good winter wheat crop even better at harvest, said Shawn Conley, Purdue University agronomist.
Setting up combines to kick out grain infected with Fusarium head blight can improve the marketability and value of a farmer's wheat crop, Conley said.
So far, Indiana's wheat crop shows few signs of the disease, also known as head scab, Conley said.
"The biggest issue I think we'll have this season is dockage, or outright refusal, of an elevator accepting grain with scabby kernels," he said. "Market prices are very good for wheat and we want to make sure we can capture as much of that price as possible. By limiting the possibility of dockage, that only enhances our bottom line."
Head scab is a fungal disease that attacks the wheat head where ears of grain -- or spikes -- develop. The disease can interrupt a wheat plant's grain-making ability, resulting in low yield. The Fusarium graminearum fungus also produces deoxynivalenol (DON), a compound extremely toxic to humans and livestock. Wheat grain with even trace amounts of DON is difficult to market.
Scab-infected kernels are smaller and lighter than healthy kernels. Conley advised farmers to prepare their combines to blow scab-infected wheat back onto the field.
"One of the ways we can alleviate some of the issues at the elevator is by turning the air up a little bit on our combines, in order to push the scabby kernels out the back so that they don't get mixed in with the rest of the grain," Conley said.
"In terms of setup, calibrating the combine per wheat variety is important. Most varieties have enjoyed this cool weather period we've had and should have larger kernels. You'll be able to identify the wheat that has scab because it will be shrunken and shriveled, and it won't be as plump as the rest of the wheat."
Purdue plant disease specialists continue to monitor the state's wheat crop for head scab outbreaks, said Greg Shaner, Extension plant pathologist.
"During visits last week to wheat fields in southeast, southwest, and north-central Indiana, we saw no head blight," Shaner said. "Most of the wheat in Indiana is probably now past the flowering stage, which is the most vulnerable stage for infection. However, infection can occur even into late milk or very early dough, so it is important to continue to monitor fields."