An Integrated Approach for Managing Fusarium head blight and Deoxynivalenol in Wheat: Lessons Learned After 12 Years of Multistate Research Dr. Pierce

An Integrated Approach for Managing Fusarium head blight and

Deoxynivalenol in Wheat: Lessons Learned After 12 Years of Multistate Research

Dr. Pierce A. PaulAssociate Professor

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Ohio Agricultural Research and Development CenterDepartment of Plant Pathology

• Fusarium graminearum• Infection

– Warm, humid weather– Anthesis and early grain-fill– Shriveled light-weight kernels– Fusarium damaged kernels (FDK)

• Grain yield and quality losses– Low test weight and grain grade

Fusarium Head Blight (FHB)

• Grain contamination with mycotoxin- DON (Vomitoxin), 3A-DON, 15A-DON, and NIV- Livestock health concerns

• Flour yield and milling and baking quality

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• Components of FHB-related lossesLower grain yield, price discounts due to DON contamination, Fusarium damaged kernels (FDK), and low test weight. • Costs associated with FHB management To minimize losses due to FHB and DON, growers are advised to implement management strategies such as: Tillage, crop rotation, cultivar resistance, and timely fungicide application, as well as grain harvesting strategies.• Impact on gross cash income (GCI)

FHB-related Losses

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• Costs associated with management are not always offset by gains in grain yield and quality.

• Fungicides only provide about 50% control and the benefit of applying a fungicide is not always sufficient to offset application cost.

• Resistant varieties are not always high-yielding. • Modifying combine harvester configurations to

remove diseased kernels during harvest improves grain quality, but it may also reduce expected yield.

• Benefits depend on yield, baseline FHB and DON levels, grain prices and price discounts due to poor grain quality.

Factors Affecting Decision making

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National Coordinated Project

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Integrated Management• Core Treatments

o Resistance (S, MS, MR)o Fungicide application

Prosaro (Tebuconazole+Prothioconazole)

o Inoculation• Cropping sequence/Rotation• Responses

o FHB Incidence and Severityo FDK,DON, NIV

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Treatment Prosaro Resistance Code

1 (Check) NO Susceptible S_UT

2 Yes Susceptible S_TR

3 NO Moderately Susceptible MS_UT

4 Yes Moderately Susceptible MS_TR

5 NO Moderately Resistant MR_UT

6 Yes Moderately Resistant MR_TR

Fungicide/Resistance treatment Combinations

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MS_UT MR-UT S_TR MS_TR MR_TR

Per

cen

t C

on

tro

l

-80

-60

-40

-20

0

20

40

60

80

100

MS_UT MR-UT S_TR MS_TR MR_TR-60

-40

-20

0

20

40

60

80

100

• Lots of data and highly variable results

• Lots of questionso How effective?o Is the combined effect additive?o How stable is the effect?o Is it economical?

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Efficacy and Additivity


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Efficacy: Overall Percent Control

100-

_

___

UTS

TRMRUTSTRMR X

XXC

UTS

TRMRTRMR X

XR

_

__

100)-1( __ TRMRTRMR RC

Measures of efficacy (effect size)

TRMRUTSTRMR XXD ___ -

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i

ii

w

zw

A formal probabilistic approach for synthesizing evidence from multiple sources

Estimated Mean Percent

Control

Individual Percent Control

22ˆ1

ii sw

Meta-Analysis: Quantitative Research Synthesis

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iii uz Effect size for study i(the result from study i

becomes a data point in the meta-analysis)

Expected effect size, overall

Among-study variability term.

Random effect of study i on the effect size.

i ~ N (0, 2)

Within-study variability term; residual or

“sampling variation”.Assume known.i ~ N (0, s2)

Meta-Analysis: The Model

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• Estimate and its sampling variance,


Efficacy: Overall Percent ControlLog of R as effect size: PROC Mixed

𝑺𝑳𝟐=𝑽

𝒏 ( 𝟏𝑿𝑪𝑲

𝟐 −𝟏

𝑿𝑴𝑮𝑴𝑻𝟐 )

𝑳=𝒍𝒏 (𝑹)=𝒍𝒏 (𝑿𝑴𝑮𝑴𝑻 /𝑿 𝑪𝑲 )=𝒍𝒏 (𝑿𝑴𝑮𝑴𝑻 )− 𝒍𝒏 (𝑿𝑪𝑲 )

𝑳=𝒍𝒏 (𝑹)

• From each study obtain treatment means, and residual variance, V 𝑿 𝒊

𝑺𝑳𝟐

• Back-transform to obtain 𝐶𝐿

𝑪=[𝟏−𝒆𝒙𝒑 (𝑳) ]𝐱𝟏𝟎𝟎

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Additivity of the integrated effectAdditive: Observed C(F+R) = Expected C(F+R)

D|R = (1 – CR) = (1 – 0.54) = 0.46

C(F+R) = CR + CF (1 – CR) = 0.54 + 0.24 = 0.78

CF|R = CF (1 – CR) = 0.53 x 0.46 = 0.24

CR = 0.54

CF = 0.53

Observed C(F+R) = 0.76

Expected C(F+R) = 0.78

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So, what have we learned?1. Combining resistance with fungicide is more

efficacious than either approach alone; 2. Relative to fungicide alone, the integrated

approach leads to comparable levels of index and DON reduction;

3. There is an additive effect of fungicide and resistance on both index and DON;

4. The integrated approach is more stable across environment; and

5. The integrated approach is more economically beneficial for a range of baseline FHB levels, grain prices and fungicide application costs.

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L. Madden and K. Willyerd (OSU)G. Milus (University of Arkansas)C. Bradley (University of Illinois)G. Bergstrom (Cornell)M. McMullen (NDSU)J. Ransom (NDSU)K. Wise (Purdue)B. Padgett (LSU)S. Wegulo (UNL)L. Osborne (SDSU)L. Sweets (University of Missouri)P. Esker (University of Wisconsin)W. Bockus (Kansas State University)D. Hershman (University of Kentucky)A. Grybauskas (University of Maryland)R. Dill-Mackey (University of Minnesota)

U.S. Wheat & BarleyScab Initiative

"This material is based upon work supported by the U.S. Department of Agriculture, under Agreement No. 59-0790-4-112. This is a cooperative project with the U.S. Wheat & Barley Scab Initiative. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture."

Acknowledgments

Dr. JD Salgado

Dr. KT Willyerd

Documents

An Integrated Approach for Managing Fusarium head blight and Deoxynivalenol in Wheat: Lessons Learned After 12 Years of Multistate Research Dr. Pierce