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
2. Major disease of wheat and barley
3. FHB +rain cool +rain warm -rain hot +rain/dry hot Wheat Blast 90% wheat crops (5 million T) Re-emergent in Brazil
4. Photo: Dr. Flávio Santana Embrapa Trigo
5. But also for other crops..
6. Trail (2009) Why does FHB matter? Trail (2009)
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
8. Episode one A new old problem
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
10. Del Ponte et al. (2005) Daily infection risk Why here, why now? How to predict it?
11. Cumulative risk Model testing
12. Cumulative risk Model testing
13. No-till Cumulative risk Growing season (year) Del Ponte et al. (2009) Climate variability effect? no till?
14. 9 years 11 locations 37 trials Meta-analysis of damage coefficients
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)
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)
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)
18. Are two sprays worth? Duffeck et al. (2020)
19. Episode Two Knowing the enemy
20. The rise of a species complex Phylogenetic species recognition based on genealogical concordance
21. FGSC species and trichothecene profile
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
23. (Del Ponte et al. 2015) Region shaping species distribution?
24. South of Paraná: new surveys > 750 isolates Pereira et al. (2020)
25. Crop and year effect on FGSC composition? Pereira et al. (2020)
26. episode Three Food in danger
27. n = 66 samples 2ppm line Del Ponte et al. (2012) Trichothecenes in wheat: NIV too!
28. Duffeck et al. (2017) DON by state
29. Duffeck et al. (2017) Zearalenone by state
30. Duffeck et al. (2017) UHPLC vs. Elisa kit
31. episode Four The chief species
32. Spolti et al. (2012) Duffeck et al (unpublished) Is F. graminearum more aggressive?
33. Is F. graminearum more aggressive? F. graminearum F. meridionale
34. Machado et al. (unpublished) Is F. graminearum more aggressive?
35. Species x Cultivar = P > 0.05 highly aggressive isolate Mendes et al. (2018) Cultivar x species effect?
36. Nicolli et al. (2015) Chemical analysis Toxigenic potential
37. Sexual fertility 1 Nicolli et al. (2015)
38. 38 * * Sexual fertility 2 Machado et al. (Unpublished)
39. Episode four Man weapons
40. Machado et al. (2017) Fungicides do work, but varies with AI
41. Machado et al. (2017) Do they protect yield?
42. + 102 kg/ha Efficacy (%) Yield gain (kg/ha) Machado et al. (2017) Estimates of mean efficacy and yield gain
43. Does a second spray pay off?
44. QoI + DMI mixtures: are they worth? Barro et al. (2020)
45. Yield gain from using mixtures? Barro et al. (2020)
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)
47. Show me the money again Barro et al. (2020)
48. episode six Failure ahead?
49. EC50 levels for 50 strains from RS Spolti et al. (2012) Sensitivity to Triazoles (TEBU and METC)
50. EC50 levels for 35 strains R2 R1 R2 Machado et al. (unpublished) Sensitivity to TEBU and Carbendazim
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?
52. Check Check Check Fungicide Fungicide Fungicide Less sensitive isolates Sensitive isolate Does it affect control efficacy?
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
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
55. Open FGSC database
56. Cooperative trial network
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
58. Thank you! @edelponte