Fusarium Graminearum Fungicide Application Control Option

Fusarium graminearum (Fg) is a serious fungal disease of cereal grains. Although yield is affected, the negative impact the disease has on grade results in poor quality grain intended for feed, malting, milling, and the biofuel industry. Recent surveys indicate Fg is established in southern Alberta and traces are present in central and northern regions of the province.
 

“Fg can be effectively controlled under normal conditions using a combination of disease prevention strategies throughout the growing season,” says Neil Whatley, crop specialist, Alberta Ag-Info Centre, Stettler. “When weather conditions are favourable for infection, and in irrigated cropping systems, an in-crop fungicide application may be considered, but only provides disease suppression.” 

 

Cereal crops are most vulnerable to Fg infection at flowering time if weather conditions are moist and warm, and if the disease is established in the lower canopy. Disease spores are spread by rain splashes and wind to infect open flowers. 

 

“Observable Fg symptoms don’t appear until the late heading stage when it is too late to apply protective fungicide,” says Whatley. “A decision to apply a fungicide must be made prior to this, at the early flowering stage. If disease risk level is assessed as moderate to high, and yield return justifies fungicide application cost, a foliar fungicide application should be applied at early flowering to protect open florets.”

 

A fungicide application is recommended if the risk level for Fg is moderate to high. Disease risk level increases when more of the following factors exist:

 

“Application of a fungicide too early is better than too late,” says Whatley. “With wheat, flowering begins three to four days after head emergence and lasts approximately seven days. The optimum stage for fungicide application is during early flowering when some visible anthers are present on the head.”