Pioneer "Goof" Demonstration - Fungicide Misapplication

Fungicide Misapplication

Goof Demo - Fungicide Misapplication

Foliar fungicide applications to corn continue to grow in popularity. According to fungicide manufacturers, crop injury associated with fungicide applications has been reported in a limited number of cases. The most frequent damage was partial to completely arrested cob development. However, properly timing a fungicide application is critical. Exactly how much crop damage can occur if a fungicide is applied at the incorrect growth stage? This goof demonstration set out to measure the potential damage.

Fungicide Misapplication

Corn ears from VT and V14 fungicide applications

This photo shows ears (left) from plants that received a ground application of a fungicide and a non-ionic surfactant (NIS) at the VT growth stage (correct application timing). The ears on the right are from plants that received the same application but at the V14 stage (too early). This photo clearly shows the potential crop injury and yield loss when a fungicide is applied at the incorrect growth stage.

Factors to Consider
Jeff Mathesius, Pioneer agronomy research manager, says foliar fungicides are a tool to help manage disease but it's important that growers understand that tool.

  • Don't Apply Too Early. Damage from fungicides and NIS is often associated with fields that were treated prior to tasseling. If the application is too early, there's a high probability that the non-ionic surfactant will damage the ears.
  • Greater Need for Fungicides in Fields with High Residues. Corn following corn and no-till and strip-till fields are likely to have more residue and with that comes a higher risk of disease pressure.
  • Know the Disease Score of the Hybrid. Mathesius says that selecting a hybrid with a strong disease score will help minimize the potential impact of disease and the need for foliar fungicides.
  • Know What is Happening in Your Field. Scouting your field for disease as well as understanding your previous cropping history and hybrid disease resistance package can help you make the right choice when deciding whether or not to apply a foliar fungicide.

Get additional information on foliar fungicides.