Trial Objective

  • To help determine if there is a positive response to yield potential by applying a foliar fungicide on the newest DEKALB® brand corn products.
  • Data from the trial can help DEKALB® agronomists provide fungicide recommendations by corn product.
  • Corn products vary in their genetic tolerance, resistance, or lack of, to different foliar diseases. Foliar fungicides can help maintain viable leaf tissue when corn products lack disease tolerance; however, can fungicides provide a benefit when corn products have tolerance or resistance to certain foliar diseases?

Experiment/Trial Design

  • Long-term fungicide application trial – at minimum of two years with data from 7 to 8 sites. A third year of data may be available for corn products with a longer life span.
  • Group block design with fungicide as the main unit and corn product as the sub-unit.
    • Untreated check
    • Delaro® Complete Fungicide applied at pre-tassel using a back-pack sprayer and high clearance boom + Turbo TwinJet nozzles (Figure 1).
      • Applied at a rate of 586 ml/hectare (237 ml/acre) in a water volume of 150 to 200 l/hectare.
    • Stratego® PRO fungicide applied at pre-tassel using a back-pack sprayer and high clearance boom + Turbo TwinJet nozzles (Figure 1).
      • Applied at a rate of 572 ml/hectare (231.5 ml/acre) in a water volume of 150 to 200 l/hectare.
  • Three replications.
  • Plot size, 10 ft x 23 ft.
  • Targeted final population of 35,000 plants/acre.
  • 2 to 7 DEKALB® brand corn products per set (Figure 1).
  • Evaluations:
    • R3 to R5 growth stage:
      • Final stand count (FNSC)
      • Disease stressor classification (DISEA)
    • R5 growth stage:
      • Staygreen (STGRN)
    • Harvest:
      • Root lodging count (RTLC)
      • Stalk lodging count (STLC)
      • Intactness above the ear (INT)
      • Shell weight (SHW)
      • Percent moisture content (MST)
      • Test weight (TWT)
Back-pack sprayer with high clearance boom and TwinJet nozzles.
Figure 1. Back-pack sprayer with high clearance boom and TwinJet nozzles.

Understanding the Results

  • Compared to the untreated checks, fungicide-treated corn in the years 2018 to 2021 showed a positive average yield response of 3.7 bu/acre (Figures 2 and 3).
  • To have a positive response to ROI, the cost of a fungicide and its application should maintain a minimum of 3 bu/acre of yield potential. 16 of the 25 corn products met or exceeded this economical threshold (Figures 4, 5, and 6).
  • 21 of the 25 corn products showed a yield increase when a fungicide was utilized (Figures 5 and 6).
  • Seasonal growing conditions play a role in the yield response to fungicides. The highest response since 2018 occurred in 2021 with an average increase of 8.5 bu/acre.
Year Untreated Check / Fungicide n = HVPOP (1000 plants/acre) STGRN (1-9) RTLP (%) STLP (%) INT (1-9) MST (%) TWT (lb/bu) YLD (bu/acre)
2018 Untreated 51 36.1 5.7 1.8 4.0 3.6 22.8 55.1 216.9 B
Stratego® PRO 51 35.7 5.5 0.7 3.2 3.7 22.9 55.6 219.8 A
Delta 51 -0.4 -0.2 -1.1 -0.8 0.1 0.1 0.5 2.9
2019 Untreated 70 35.2 4.7 0.4 2.0 4.8 27.4 52.4 214.5 A
Stratego® PRO 70 34.9 4.3 0.5 1.8 4.6 27.4 52.4 215.3 A
Delta 70 -0.3 -0.4 0.1 -0.2 -0.2 0.0 0.0 0.8
2020 Untreated 90 33.3 4.4 0.8 0.3 3.8 22.5 53.3 199.4 A
Delaro® Complete 90 33.2 4.2 0.6 0.3 3.7 22.5 53.4 201.4 A
Delta 90 -0.1 -0.2 -0.2 0.0 -0.1 0.0 0.1 2.0
2021 Untreated 81 35.6 6.7 0.9 1.2 4.5 23.7 54.5 228.2 B
Delaro® Complete 81 35.3 6.3 1.0 1.6 4.3 23.9 54.8 236.7 A
Delta 81 -0.3 -0.4 0.1 0.4 -0.2 0.2 0.3 8.5
Overall Untreated 292 34.9 5.6 0.9 1.6 4.2 24.1 53.7 215.3 B
Fungicide 292 34.6 5.3 0.7 1.5 4.1 24.1 53.9 219 A
Delta 292 -0.3 -0.3 -0.2 -0.1 -0.1 0.0 0.2 3.7
Figure 2. Performance data for a fungicide application for the years 2018, 2019, 2020, and 2021 in Bayer Canada Market Development Trials. A fungicide application showed a positive response each year compared to the untreated checks.
RM Treatment n = HVPOP (1000 plants/acre) STGRN (1-9) RTLP (%) STLP (%) INT (1-9) MST (%) TWT (lb/bu) YLD (bu/acre) Delta (bu/acre)
80 Untreated 27 34.5 4.1 0.2 1.1 3.3 24.0 52.3 183.0 4.3 *
Fungicide 27 34.3 3.7 0.2 1.8 3.0 24.2 52.5 187.3
85 Untreated 46 34.5 5.9 0.3 0.4 4.4 24.1 54.2 208.1 3.8 *
Fungicide 46 34.4 5.6 0.5 0.5 4.3 24.2 54.5 211.9
90 Untreated 50 35.1 5.9 0.6 1.2 4.6 21.9 54.0 204.1 1.1
Fungicide 50 34.6 5.5 0.7 0.5 4.5 22.2 54.2 205.2
95 Untreated 32 35.1 5.5 4.1 5.2 3.3 24.3 54.0 219.8 4.1 *
Fungicide 32 34.6 5.2 1.1 2.8 3.2 24.4 54.3 223.8
100 Untreated 62 34.8 5.1 0.1 1.1 3.7 25.1 53.8 242.2 3.0
Fungicide 62 34.5 5.0 0.3 1.3 3.5 25.0 53.8 245.2
105 Untreated 75 35.0 6.8 1.3 1.6 5.0 24.6 53.5 226.0 6.4 *
Fungicide 75 35.0 6.4 1.5 2.4 4.8 24.5 53.7 232.4
All Untreated 292 34.9 5.6 0.9 1.6 4.2 24.1 53.7 215.3 3.7 *
Fungicide 292 34.6 5.3 0.7 1.5 4.1 24.1 53.9 219.0
* Significant difference (p < 0.05)
Figure 3. Fungicide treatment results by corn product relative maturity (RM), 2018-2021. Bayer Canada Market Development Trials.
Figure 4 is a piano chart of each corn product at each location from 2018 through to 2021. 59.6 of the comparisons are positive
Figure 4. Yield delta from Canada Market Development Trials for each corn product at each location (2018-2021).
Figure 5 is showing average yield for fungicide treated corn over untreated corn. This test was on lower-maturity corn products
Figure 5. Average yield advantage for fungicide-treated corn over untreated corn; lower-maturity corn products. Bayer Canada Market Development Trials.
figure 6 shows the average yield advantage for fugnicide treated corn over un-treated corn on higher maturity corn products
Figure 6. Average yield advantage for fungicide-treated corn over untreated corn; higher-maturity corn products. Bayer Canada Market Development Trials.
Figure 7 is showing the average yield advantage for newly commercialized corn products treated with a fungicide. Data for each corn product is the for the year it was released.
Figure 7. Average yield advantage for newly commercialized corn products treated with a fungicide. Data for each corn product is for the year of release.
figure 8 is showing average yield and economical win percentage for lower maturity DEKALB brand corn products treated with a fugnicide.
Figure 8. Average yield and economical win percentage for lower-maturity DEKALB® brand corn products treated with a fungicide.
Figure 9 is showing average yield and economical win percentage for higher matruity DEKALB brand corn products treated with a fungicide
Figure 9. Average yield and economical win percentage for higher-maturity DEKALB® brand corn products treated with a fungicide.
Figure 10 is showing average yield and economical win percentage for new dekalb brand corn products treated with a fungicide in the year of their release
Figure 10. Average yield and economical win percentage for new DEKALB® brand corn products treated with a fungicide in their year of release.
Figure 11 is showing average corn yield by previous crop when treated with a fungicide.
Figure 11. Average corn yield by previous crop when treated with a fungicide. Continuous corn showed an average of a 5.1 bu/acre increase compared to an average increase of 3.2 bu/acre for corn grown in a rotational program.
Figure 12 is showing the average corn yield by tillage method when treated with a fungicide.
Figure 12. Average corn yield by tillage method when treated with a fungicide.

Key Learnings

  • The use of a fungicide helps maintain yield potential when labeled foliar diseases develop and growing conditions favor pathogen development, increase, and spread.
  • This study showed an average increase of 3.7 bu/acre when a fungicide was used and can be higher when disease incidence is higher.
  • Corn products should be evaluated for genetic resistance or tolerance to different foliar diseases. Because of seasonal growing conditions and specific pathogen development, it is difficult to determine which pathogen may or may not be problematic in each growing season.
  • Continued research is needed to evaluate the response of newly commercialized corn products to foliar fungicides.

Legal Statements

The information discussed in this report is from a multiple site, replicated demonstration. This informational piece is designed to report the results of this demonstration and is not intended to infer any confirmed trends. Please use this information accordingly.

Bayer is a member of Excellence Through Stewardship® (ETS). Bayer products are commercialized in accordance with ETS Product Launch Stewardship Guidance, and in compliance with Bayer’s Policy for Commercialization of Biotechnology-Derived Plant Products in Commodity Crops. These products have been approved for import into key export markets with functioning regulatory systems. Any crop or material produced from these products can only be exported to, or used, processed or sold in countries where all necessary regulatory approvals have been granted. It is a violation of national and international law to move material containing biotech traits across boundaries into nations where import is not permitted. Growers should talk to their grain handler or product purchaser to confirm their buying position for these products. Excellence Through Stewardship® is a registered trademark of Excellence Through Stewardship.

ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Performance may vary from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields.

Bayer, Bayer Cross, DEKALB®, Delaro®, RIB Complete® and Stratego® are registered trademarks of Bayer Group. Used under license. All other trademarks are the property of their respective owners. Bayer Crop Science Inc. is a member of CropLife Canada. ©2022 Bayer Group. All rights reserved. 1211_32500