Fusarium head blight (FHB) in Brazil: what have we learned in 15 years?

Summary of almost 20 of research on Fusarium head blight of wheat that started during my PhD in 2000 year. I provide a historical perspective of the work organized by interests that developed over time during the establishment of my research program on the topic.

Transcript

1. Fusarium head blight (FHB) in Brazil:
   what have we learned in 15 years?
   Emerson M. Del Ponte
   Prof. Plant Pathology/Epidemiology
   

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2. Major disease of wheat and barley
   

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3. FHB
   +rain cool
   +rain warm
   -rain hot
   +rain/dry hot
   Wheat Blast
   90% wheat crops
   (5 million T)
   Re-emergent in Brazil
   

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4. Photo:
   Dr. Flávio Santana
   Embrapa Trigo
   

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5. But also for other crops..
   

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6. Trail (2009)
   Why does FHB matter?
   Trail (2009)
   

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7. My FHB research in 6 episodes
   A new old problem
   Knowing the enemy
   The chief species
   Food in danger
   Man weapons
   Statistical modelling
   Computer simulation
   Disease forecasting
   Field surveys
   Molecular Identification
   Population genetics
   Chemistry
   Immunology
   Pathogen biology and ecology
   Plant-pathogen interaction
   Fungicide efficacy
   Meta-analysis
   Economic analysis
   Failure ahead?
   Fungicide resistance
   Phenotypic and molecular
   1
   2
   3
   4
   5
   6
   

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8. Episode one
   A new old problem
   

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9. Season Yield losses (%)
   1984 - 1994 5.4
   2000 17.5
   2001 13.4
   2002 11.6
   2003 26.2
   2004 12.0
   2005 22.2
   2007 39.8
   2008 23.2
   2009 32.2
   2010 17.8
   A problem is noticed
   E.M. Reis
   R.T. Casa
   

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10. Del Ponte et al. (2005)
    Daily infection risk
    Why here, why now? How to predict it?
    

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11. Cumulative risk
    Model testing
    

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12. Cumulative risk
    Model testing
    

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13. No-till
    Cumulative risk
    Growing season (year) Del Ponte et al. (2009)
    Climate variability effect? no till?
    

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14. 9 years
    11 locations
    37 trials
    Meta-analysis of damage coefficients
    

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15. = 4,419.5 kg ha-1
    = -46.3 kg ha-1
    = 2,883.6 kg ha-1
    = -46.3 kg ha-1
    Damage coefficient = -1.05% pp -1 Damage coefficient = -1.60% pp -1
    Estimation of damage coefficients
    Duffeck et al. (2020)
    

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16. Crop simulation
    (10 dates x 28 years)
    FHB index
    FHB
    risk
    Attainable
    yield
    Yield
    losses
    (FHB)
    Damage
    coefficient (Dc)
    -1.05
    %
    1980-1989 1990-1999 2000-2007
    10.3% 10.2%
    5.8%
    Simulations of historical yield losses
    Duffeck et al. (2020)
    

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17. FHB index
    Fungicide spray
    (1x or 2x)
    Probability of
    non-offsetting costs
    $
    Actual yield
    (Treated)
    Actual yield
    (Nontreated)
    Yield diff.
    (kg ha-1)
    Are fungicides profitable?
    Duffeck et al. (2020)
    

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18. Are two sprays worth?
    Duffeck et al. (2020)
    

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19. Episode Two
    Knowing the enemy
    

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20. The rise of a species complex
    Phylogenetic species recognition based on genealogical concordance
    

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21. FGSC species and trichothecene profile
    

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22. (Scoz et al 2009; Astolfi et al. 2012; Del Ponte et al. 2015)
    > 850 FGSC strains (5 years)
    Diverse population of species and toxin types
    

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23. (Del Ponte et al. 2015)
    Region shaping species distribution?
    

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24. South of Paraná: new surveys > 750 isolates
    Pereira et al. (2020)
    

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25. Crop and year effect on FGSC composition?
    Pereira et al. (2020)
    

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26. episode Three
    Food in danger
    

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27. n = 66 samples
    2ppm line
    Del Ponte et al. (2012)
    Trichothecenes in wheat: NIV too!
    

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28. Duffeck et al. (2017)
    DON by state
    

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29. Duffeck et al. (2017)
    Zearalenone by state
    

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30. Duffeck et al. (2017)
    UHPLC vs. Elisa kit
    

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31. episode Four
    The chief species
    

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32. Spolti et al. (2012) Duffeck et al (unpublished)
    Is F. graminearum more aggressive?
    

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33. Is F. graminearum more aggressive?
    F. graminearum F. meridionale
    

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34. Machado et al. (unpublished)
    Is F. graminearum more aggressive?
    

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35. Species x Cultivar = P > 0.05
    highly aggressive isolate
    Mendes et al. (2018)
    Cultivar x species effect?
    

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36. Nicolli et al. (2015)
    Chemical analysis
    Toxigenic potential
    

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37. Sexual fertility 1
    Nicolli et al. (2015)
    

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38. 38
    * *
    Sexual fertility 2
    Machado et al. (Unpublished)
    

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39. Episode four
    Man weapons
    

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40. Machado et al. (2017)
    Fungicides do work, but varies with AI
    

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41. Machado et al. (2017)
    Do they protect yield?
    

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42. + 102 kg/ha
    Efficacy
    (%)
    Yield gain
    (kg/ha)
    Machado et al. (2017)
    Estimates of mean efficacy and yield gain
    

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43. Does a second spray pay off?
    

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44. QoI + DMI mixtures: are they worth?
    Barro et al. (2020)
    

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45. Yield gain from using mixtures?
    Barro et al. (2020)
    

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46. Effect size Yield Return (%)
    Fungicidea kb D SE(D) CI
    L
    c CI
    U
    c P value Y CI
    L
    c CI
    U
    c
    PYRA + METC 70 532.08 46.40 441.14 623.02 <0.0001 17.17 14.30 20.11
    TFLX + PROT 45 494.99 45.09 406.60 583.38 <0.0001 16.21 13.14 19.37
    TEBU 25 448.20 54.04 342.27 554.13 <0.0001 14.68 11.24 18.22
    AZOX + TEBU 25 462.43 48.92 366.53 558.32 <0.0001 14.74 11.54 18.02
    TFLX + TEBU 40 468.24 42.43 385.08 551.41 <0.0001 14.66 11.92 17.46
    PYRA + METC
    1X
    23 413.72 53.66 308.53 518.90 <0.0001 12.97 9.70 16.35
    Estimates of mean efficacy and yield gain
    Barro et al. (2020)
    

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47. Show me the money again
    Barro et al. (2020)
    

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48. episode six
    Failure ahead?
    

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49. EC50 levels for 50 strains from RS
    Spolti et al. (2012)
    Sensitivity to Triazoles (TEBU and METC)
    

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50. EC50 levels for 35 strains
    R2
    R1
    R2
    Machado et al. (unpublished)
    Sensitivity to TEBU and Carbendazim
    

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51. F. graminearum less sensitive to TEBU
    Machado et al. (unpublished)
    R2
    R1
    R2
    F. graminearum others
    F. graminearum others
    15-ADON
    15-ADON
    15-ADON
    Are EC50 dependent on FGSC species?
    

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52. Check
    Check
    Check
    Fungicide
    Fungicide
    Fungicide
    Less sensitive isolates Sensitive isolate
    Does it affect control efficacy?
    

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53. 1. Previous crop not important risk factor in the subtropics (no-till)
    2. At least two important species/chemotypes to concern
    3. DON and NIV should be a target in surveys (only DON now)
    4. One seems more adapted to wheat environments (F. graminearum)
    5. Breeders should use the most aggressive strains
    Lessons learned
    

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54. 6. One spray of tebuconazole is a cost-effective choice (yield)
    7. Premixes (DMI+QoI) likely do not break even on costs
    8. The pathogen may be adapting to fungicides - future concern?
    Lessons learned
    

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55. Open FGSC database
    

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56. Cooperative trial network
    

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57. Key Collaborators
    Dr. J. Maurício Fernandes
    Dr. Gary Bergstrom
    Dr. Willingthon Pavan
    Dr. Dauri Tessmann
    Dr. Todd Ward
    Dr. Eliana Furlong
    Dr. Casiane Tibola
    Dr. Flávio Santana
    Dr. Lisa Vaillancourt
    Graduate Students (2008 - now)
    Paula Astolfi
    Piérri Spolti
    Paulo R. Kuhnem Jr.
    Camila Nicolli
    Gabriela Mendes
    Franklin Machado
    Maíra Duffeck
    Jhonatan Barro
    Acknowledgements
    

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58. Thank you!
    @edelponte
    

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