2023 PAR (Product & Agronomy Research) Report: Foliar Fungicide Timing
BY Dairyland Seed Agronomy Team
Description:
With the onset of polycyclic diseases such as tar spot, the timing of fungicide applications has become a major topic of discussion. Structured fungicide applications have become common practice in many management strategies. Common timings for foliar fungicides are V5, VT (tassel), and R2-3. This trial will look at these single applications as well as combined timings. The environment and the time of infection will determine the impact of fungicide applications, and notes on foliar disease pressure will be taken throughout the growing season.
- Wabash, IN Hybrids DS-5177AM™ and DS-4510Q™
- St Johns MI Hybrids DS-3601AM™ and DS-4510Q™
- Fungicide applied, Approach Prima 6.8 ounces per acre
Treatments:
Wabash, IN
- Untreated
- V5
- V5+VT
- VT
- VT+ R2
- R2
- V5+VT+R2
St Johns, MI
- Untreated
- VT
- R2
Results
2022
2023
Wabash: A combination of DS-4510Q™ and DS-5177AM™
St. Johns: A combination of DS-3601AM™ and DS-4510Q™
Conclusion:
The Wabash, IN site did not show any significant difference between treatments. We experienced foliar diseases in this plot and scoring between diseases pressure at tassel time. There was a slight difference in disease infection between treatments, but late season notes scored all hybrids about the same. It is difficult to show separation in treatments when we do not have control of the environment. GLS, NCLB and tar spot were all noted across the plot at the Wabash site, but at harvest, we did not see any significant yield separation in treatments.
The St. Johns, MI site showed a significant separation in yield. The VT timing was significantly better than the untreated check. VT is the recommended timing for fungicide application for disease control, as well as added plant health, by most fungicide manufactures. The St. Johns site did not see significant disease pressure until after the corn was dented. This is the stage where it is not beneficial to apply a fungicide. Fungicide applications can have plant health benefits. This added health is likely what contributed to a positive response with fungicide applications in the St Johns, MI location.
Fungicide timing continues to be a topic of discussion among growers. Environment, disease presence and development stage of the crop all weigh in when making the decision to apply a foliar fungicide. Digital disease models such as Tar Spotter, as well as others, can be a good reference or starting point when deciding when and where to scout for disease pressure and determine if a fungicide application is needed. We will continue to look at fungicide applications and their timing efficacy.
Brian Weller
Western Region
507.456.3034
Rod Moran
Western Region
507.456.3034
Dan Ritter
Central Region
219.863.0583
Branden Furseth
Northern Region
608.513.4265
Mark Gibson
Eastern Region
260.330.8968
Amanda Goffnett
Eastern Region
989.400.3793
Ryan Mueller
Eastern Region
989.400.3793