Wheat Disease Management in Ohio

Bulletin 785

Foliar Fungicides

Steps for Effective Use of Foliar Fungicides to Control Diseases on Wheat

5. Consider the Factors Limiting Profitability of Fungicide Applications.

   Fungicides are tools that need to be used appropriately to achieve the desired result. Fungicides do not improve yield of a crop, but they do help reduce losses caused by certain diseases. They do not control all diseases. They are used to manage a few specific, but common leaf diseases.

   Fungicide treatment is not profitable when:

   • Resistant or moderately resistant varieties are treated.
   • Fungicide was applied after flowering.
   • Fungicide was applied after the flag leaf was severely diseased.
   • Fungicide rate was cut.
   • Not enough water was applied with the fungicide to achieve adequate coverage.

   It is generally not profitable to apply a fungicide to wheat when the grain price is less than $2.25/bu because it will take a 10% yield response just to pay for the fungicide plus application — 10% of 70 bu/A = 7 bu; 7 bu x $2.25 = $15.75/A for fungicide plus application cost.

   Lastly, it is better to apply a fungicide a little early rather than too late.