Soybean R3 Fungicide Trials
Key question: Are fungicides applied at R3 effective at reducing foliar disease and increasing yield?
Treatments: Strips with fungicide applied at R3 vs. strips with no fungicide application.
*Farmer’s choice of product used.
Fungicide trials information and results
- Farmer selected varieties and management.
- Farmer selected fungicide used at R3. Provided as-applied map to document treatment locations.
- Fields were scouted twice at the same 40 points in the field:
- Once pre-spray (~R2).
- Once post spray. Goal was 14 days after R3 application.
- Drones were used to obtain field overview and high resolution (15 feet above canopy) imagery at both scouting dates.
- Farmer provided yield map.
To document differences in disease between the treatment strips, scouting for foliar diseases was performed at several locations within each treatment strip prior to and approximately two weeks following the fungicide application at the R3 stage. In addition, aerial imagery was taken at each of the scouting points to visually document the differences.
Results summary (2018-2021)
Soybean R3 Foliar Fungicide Trial locations
There were 10 trials in 2018, 12 in 2019, 11 in 2020 and 11 in 2021.
If you are interested in participating in this trial in 2022 or have questions/comments, please contact your local Extension Agronomist or Agricultural Engineer.
R3 Fungicide for Soybean: Location details
Note: First two numbers in location ID is the year.
R3 fungicide application detail
R3 Fungicide for Soybean: Effect on yield
How to interpret graph:
- Green diamonds are the mean effect of fungicide treatment for each location; diamonds right of the center line indicate the mean effect at that location was positive.
- Black (no R3 fungicide) and gold (R3 fungicide) symbols are strip yields for each location, as the difference from the location mean.
- Credible interval is the expected yield effect of R3 Fungicide based on these 43 trials farms (95% to 5% probability).
This graph summarizes 43 strip trials including 495 strips.
- >5 B/A response - 2 locations
- >3 B/A response - 11 locations
- >1 B/A response - 24 locations
- R3 fungicide increased yield.
- Mean effect was 1.7 bushels per acre (95% credible interval is 1.2 to 2.1 bushels per acre) across 43 trials.
Disease rating is on a scale of 0 to 100. Disease index is calculated as the incidence (%) times the severity (0 to 100). A score of 25 or greater is considered a high disease index. Greater than 50 is very high.
Year-by-year yield summary
Conclusions: This trial assesses effectiveness farmer management of R3 fungicide on soybean, not a specific product. Over four years and these farms there is a 50% chance that R3 fungicide increased yield more than 1.5 bu./A. Over four years and these farms there is a 98% chance that R3 fungicide increased yield more than 1.0 bu./A.
Location summary reports
This on-farm research was supported by the Missouri Soybean Merchandizing Council (award No. 18-415) and University of Missouri Extension. This on-farm research was only possible with the cooperation of Missouri Soybean farmers who volunteered to implement trials on their fields and the Regional MU Extension faculty that supported them.