Wheat Response to Foliar Fungicide Application Timing


Evaluate response of wheat varieties with varying levels of head scab resistance to foliar fungicide application timing.

Study Description

  • Pioneer® brand varieties and disease tolerance ratings
Variety Head Scab Powdery Mildew
25R32 7 7
25R39 5 4
25R40 4 7
  • Fungicide timings and products:
--Early (GS9) Quilt®
--Late (GS10.5) Carumba® (Lancaster)
  Prosaro® (Centre)
--Combination early and late
--Non-treated control

Locations Tested

  • Conducted in cooperation with Dr. Greg Roth, Penn State University.
  • 2 locations:
    • Rock Springs, Penn. (Centre County)
    • Landisville, Penn. (Lancaster County)



  • No significant differences in yield among varieties and fungicide treatments were observed.

Rock Springs:

  • All fungicide treatments significantly reduced symptoms of powdery mildew and septoria leaf blotch.
  • Head scab symptoms were reduced by the late and combination fungicide treatments but not the early treatment.
  • A significant interaction between the effects of variety and fungicide treatment on yield was observed (Figure 1).
    • All fungicide treatments significantly increased yield of 25R39.
    • Only the combination treatments significantly increased yield of 25R32 and 25R40.  
  • Yield results appeared to be most closely associated with control of powdery mildew.
    • 25R39 has lower genetic resistance to powdery mildew relative to the other 2 varieties and had greater symptoms in the non-treated control (Figure 2).
    • Increased yield with the combination treatment on 25R32 and 25R40 was likely due to control of low levels of all 3 diseases. 


Figure 1. Wheat yield response to fungicide at Rock Springs.


Figure 2. Powdery mildew symptoms with no treatment.

Research conducted by Dr. Greg Roth, Penn State University, as a part of the Pioneer Crop Management Research Awards (CMRA) Program. This program provides funds for agronomic and precision farming studies by university and USDA cooperators throughout North America. The awards extend for up to 4 years and address crop management information needs of Pioneer agronomists, Pioneer sales professionals and customers.


2012 data are based on average of all comparisons made in 2 locations through Aug. 21, 2013. Multi-year and multi-location is a better predictor of future performance. Do not use these or any other data from a limited number of trials as a significant factor in product selection. Product responses are variable and subject to a variety of environmental, disease, and pest pressures.  Individual results may vary. PIONEER® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents. All products are trademarks of their manufacturers.