In general, the use of foliar fungicides is recommended when foliar disease pressure is expected to be high. Conditions that favor foliar diseases in corn include continuous corn, no-till conditions and susceptible hybrids. If corn does not follow corn, fields are tilled and/or hybrids have tolerance to disease, fungicides are less likely to provide a benefit.
There is some evidence that foliar fungicides may increase yields when little to no disease pressure is evident. There are some very limited cases, where yields were actually reduced from fungicide treatments.
The current recommendation is to follow integrated pest management practices, where fungicides are sprayed only when the risk of disease is high.
For more information on this or other topics related to corn production, contact your state extension corn specialist or your local extension educator/agent.
The following is the link to the corn extension specialists: state extension corn specialist
