1. Conducting Sound On-Farm Research
2013 Agronomic Crops In-Service
Conducting Sound On-Farm Research
Dr. Pierce A. Paul
The Ohio State University/OARDC
Department of Plant Pathology
2013 Agronomic Crops In-Service

2. 2013 Agronomic Crops In-Service
Outline
Designing an On-Farm Trial
Experimental design
CRD, RCBD, Split-plot
Data Analysis
Interpreting Results
Case Study – Fungicide Effect on Yield
Field trials
Analyzing data and interpreting results
Baseline yield and foliar disease effect
Economic analysis
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

3. Experimental Design and Layout
2013 Agronomic Crops In-Service

4. Designing An On-Farm Trial
Research Question
Decide on treatments and check(s)
Non-”treated” check
Universal resistant/susceptible variety/hybrid
Experimental design and layout
Replication (n) and randomization
Data Collection and analysis
Interpretation of results
Presentation of findings
2013 Agronomic Crops In-Service

5. Experimental Design, Measurement Scale
Layouts
Measurement scales
1-way
2-way factorial
Split plot
Repeated measures
Continuous
Discrete (count)
Binary (0, 1)
Ordinal (ordered categories)
The experiment design and measurement scale affect the type of analysis that can and should be done.
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

6. One-way Layout Complete Randomized Design
C_3 B_2 A_2 C_1 A_3 B_1 C_2 A_1 B_3
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

7. One-way Layout Randomized Complete Block Design
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

8. One-way Layout Randomized Complete Block Design
Field Snyder Farm Wooster, Ohio
Check
Treated
SR250
Left Side
Center-left
Center-right
Right Side
Gradient
2013 Agronomic Crops In-Service

9. One-way Layout Randomized Complete Block Design
Left Side
Center-left
Center-right
Right Side
Check
Treated
Field Snyder Farm Wooster, Ohio
SR250
Gradient
2013 Agronomic Crops In-Service

10. One-way Layout Randomized Complete Block Design
Wooster
Defiance
Van Wert
Columbus
Check
Treated
Check
Treated
Check
Treated
Check
Treated
2013 Agronomic Crops In-Service

11. One-way Layout Randomized Complete Block Design
Wooster 2003
Wooster 2010
Wooster 2004
Wooster 2012
Check
Treated
Check
Treated
Check
Treated
Check
Treated
2013 Agronomic Crops In-Service

12. One-way Layout Randomized Complete Block Design
What are Blocks (blocking factors)?
Locations within a field
Soil type, moisture gradient, Microclimate etc.
Varieties/hybrids within a field
Fields within a county/state/country
Time - Year/Growing season
Combinations of the above
Uniformity/homogeneity within blocks
2013 Agronomic Crops In-Service

13. ONE BLOCK OF AN EXPERIMENT
Two-way Factorial
Two factors (treatments)
Variety (three levels)
Green, Red and Blue
Fungicide (three levels)
Check, horizontal, and vertical
NINE treatment combinations
ONE BLOCK OF AN EXPERIMENT
FIELD EXPERIMENT
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

14. ONE BLOCK OF AN EXPERIMENT
Split-plot Layout
Two factors (treatments)
Variety (three levels)
Green, Red and Blue
Fungicide (three levels)
Check, horizontal, and vertical
NINE treatment combinations
ONE BLOCK OF AN EXPERIMENT
15 ft
65 ft
30 ft
30 ft
FIELD EXPERIMENT
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

15. Split-plot Data Analysis
What if I did not realize or ignored the fact that the experiment was a split plot
proc mixed data=Demo;
title2 'Incorrect model specification';
class Variety Block Fungicide;
model Yield = Variety Fungicide Variaty*Fungicide;
run;
I know that the experiment was a split plot
proc mixed data=Demo;
title2 'Correct model specification';
class Variety Block Fungicide;
model Yield = Variety Fungicide Variaty*Fungicide;
random Block(Variety);
run;
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

16. Split-plot Data Analysis
What if I did not realize or ignored the fact that the experiment was a split plot
Effect DF DF F Value Pr > F
Variety
Fungicide
Variety*Fungicide
I know that the experiment was a split plot
Effect DF DF F Value Pr > F
Variety
Fungicide
Variety*Fungicide
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

17. Inter-plot Interference
Spray
Spray
How do we deal with it?
Leave untreated strip (border) between plots
Leave wide space between plots
Remove outer rows and collect data on center rows only
Adjust the spray boom?
Prosaro
Check
Headline
2013 Agronomic Crops In-Service

18. BEFORE you conduct your experiment, not after you collect data!!
SEEK HELP:
BEFORE you conduct your experiment, not after you collect data!!
2013 Agronomic Crops In-Service

19. Presenting and Interpreting Results
2013 Agronomic Crops In-Service

20. 2013 Agronomic Crops In-Service
Interpreting Graphs
2013 Agronomic Crops In-Service

21. 2013 Agronomic Crops In-Service
Interpreting Graphs
2013 Agronomic Crops In-Service

22. 2013 Agronomic Crops In-Service
Interpreting Graphs
2013 Agronomic Crops In-Service

23. 2013 Agronomic Crops In-Service
Interpreting Graphs
2013 Agronomic Crops In-Service

24. 2013 Agronomic Crops In-Service
Interpreting Graphs
2013 Agronomic Crops In-Service

25. A CASE STUDY: Corn Yield Response to Foliar Fungicides
2013 Agronomic Crops In-Service

26. Evaluating Yield Response
Widely Marketed Fungicides for field corn
Class
Common name
Trade name(s)
DMI
(Triazole)
Propiconazole
Tilt, Bumper, Propimax
Prothioconazole
Proline
Tebuconazole
Folicur
QoI
(Strobilurin)
Azoxystrobin
Quadris
Pyraclostrobin
Headline
Mixed Mode of Action
Azoxystrobin + Propiconazole
Quilt, Quilt Xcel
Trifloxystrobin + Propiconazole
Stratego
Trifloxystrobin + Prothioconazole
Stratego YLD
Pyraclostrobin + Metconazole
Headline AMP
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

27. 2013 Agronomic Crops In-Service
Introduction
Cost and Benefits of using foliar fungicides
Why use foliar fungicides (Benefits)?
Disease control
Yield increase
Disease control without yield increase
Yield increase with little or no disease
Cost of using foliar fungicide
Financial - Product and application costs
Benefits do not always offset costs
Fungicide resistance
Loss of efficacy against diseases
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

28. Evaluating Yield Response
In ~ 1.6 million acres sprayed
Application Cost: $23.00
= $36,800,000.00
Corn price: $3.30/bu
Breakeven: 7bu/A
2013 Agronomic Crops In-Service

29. Evaluating Yield Response
Concerns/Questions
Increased production cost
Fungicide resistance concerns
Environment, health and safety concerns
Yield and economic benefits of foliar fungicides
Is there a positive yield response?
Under what conditions is a positive response most likely?
Is the response sufficient to offset application cost?
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

30. Evaluating Yield Response
Foliar fungicide trials
Raw data from fungicide research and on-farm trials
Data from published foliar fungicide trials
Fungicide and Nematicide Tests (F&N Tests)
Plant Disease Management Reports (PDMR)
A total of 212 studies from 14 states (RCBD)
187 as raw data and 25 as F&N/PDMR summaries
Fungicides (3-6 replicate blocks)
Headline (23.6% pyraclostrobin )
Stratego (11.4% propiconazole % trifloxystrobin)
Quilt (7% azoxystrobin % propiconazole)
Quadris (22.9% azoxystrobin)
2013 Agronomic Crops In-Service

31. Evaluating Yield Response
Foliar fungicide trials – Average Yield
250
290
220
200
200
180
160
150
150
2013 Agronomic Crops In-Service

32. Evaluating Yield Response Research Synthesis – Integrating Results
A measure of fungicide effect on yield
YieldDiff (D) = YieldTreated − YieldCheck
Meta-analysis: Essentially a method of obtaining weighted averages of yield difference
2013 Agronomic Crops In-Service

33. Variable Yield Response to Foliar Fungicides
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

34. Mean Yield Response to Foliar Fungicides
2013 Agronomic Crops In-Service

35. Why such high variability?
Different
Disease (pest) pressure
Soil type (fertility)
Weather conditions
Hybrid
Yield potential and Resistance
Other factors
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

36. Why such high variability?
Weather
Nitrogen
Hybrid - Genetics
Previous crop
Plant Population
Tillage
Growth Regulator
- Strobilurins
From Dr. Fred Below,

37. Hybrid Baseline Yield Effect
Baseline (actual) yield affected by:
Genetics
Soil and Weather conditions - fertility
Pest and disease pressure
Trials grouped by yield
Less than 145 bu/A
Between 145 and 190 bu/A
Greater than 190 bu/A
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

38. Hybrid Baseline Yield Effect
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

39. 2013 Agronomic Crops In-Service
Foliar Disease Effect
Foliar Diseases Affect:
Crop Growth and Development
Green leaf area - photosynthesis
Stalk strength
Effect depends on disease level
Trials grouped by Ear Leaf Disease Severity (GLS, NCLB, Rust) at R4/R5
Less than 5% Severity
Greater than 5% Severity
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

40. 2013 Agronomic Crops In-Service
Foliar Disease Effect
9.67 bu
3.3 bu
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

41. Chance of Recovering Fungicide and Application Cost
What is the chance (probability) of the yield response being sufficient to cover the cost of fungicide application?
Average yield difference
Breakeven yield
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

42. Chance of Recovering Fungicide and Application Cost
If application cost is $25/acre and
Grain price is $4/bushel
Then, YLDB = 6.3 bushels
When Disease < 5%
D = 3.30 bu/A
When Disease > 5%
D = 9.67 bu/A
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

43. Chance of Recovering Fungicide and Application Cost
Grain price $4/bu vs. $7/bu
Chance of breakeven
2013 Agronomic Crops In-Service

44. Chance of Recovering Fungicide and Application Cost
Disease < 5% vs. > 5%
Chance of breakeven
2013 Agronomic Crops In-Service

45. Chance of Recovering Fungicide and Application Cost
Grain price $7/bu + Disease > 5%
Chance of breakeven
Grain price $4/bu + Disease < 5%
2013 Agronomic Crops In-Service

46. Chance of Recovering Fungicide and Application Cost
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

47. Chance of Recovering Fungicide and Application Cost
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

48. IS THERE AN APP FOR THIS STUFF?
OKAY!!!
IS THERE AN APP FOR THIS STUFF?
2013 Agronomic Crops In-Service

50. 2013 Agronomic Crops In-Service
Acknowledgements
L. V. Madden, The Ohio State University/OARDC
C. A. Bradley, University of Illinois
A. E. Robertson, Iowa State University
P. D. Esker, University of Wisconsin
G. P. Munkvold, Iowa State University
G. Shaner, Purdue University
K. A. Wise, Purdue University
D. K. Malvick, University of Minnesota
T. W. Allen, Mississippi State University/DREC
Grybauskas, University of Maryland
P. Vincelli, University of Kentucky
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service

51. 2013 Agronomic Crops In-Service
Acknowledgements
We gratefully acknowledge and appreciate the financial support for this project from: (1) USDA-NIFA Project No (“Development of IPM-Based Corn Fungicide Guidelines for the North Central States”) and (2) USDA-NIFA Project No (“Sustainable Disease Management on Field Corn in the U.S. Corn Belt”)
We gratefully acknowledge and appreciate funding for this project from USDA-NIFA programs
2013 Agronomic Crops In-Service
2013 Agronomic Crops In-Service