1. Fusarium Head Blight of Wheat: Progress and Challenges Ruth Dill-Macky David Van Sanford – Erik De Wolf – Pierce Paul IWC2015 - Sydney Australia

2. Fusarium Head Blight re-emerged in 1992 the most important disease to limit wheat production in the United States increasing important globally

3. Fusarium the most prevalent toxin-producing fungi of the northern temperate regions Fusarium toxins are found on infested wheat throughout America, Europe and Asia Fusarium graminearum and other species produce mycotoxins regulated and effect grain marketing

4. Hard Red WinterHard Red SpringWhiteSoft Red WinterDurum USA wheat production areas - shown by class - 1993-1996 yield losses >2.3 billion USD

5. Hard Red WinterHard Red SpringWhiteSoft Red WinterDurum USA wheat production areas - shown by class - 1996 - DON conversion of all white wheat to feed

6. Hard Red WinterHard Red SpringWhiteSoft Red WinterDurum USA wheat production areas - shown by class - chronic DON contamination significant yield losses 1996-2003

7. USWBSI Variety Development Gene Discovery & Engineering Resistance Fungicides Disease Forecasting Models Pathogen Biology Food Safety collaborative research effort since 1997 - funding from USDA 24 states - and grant universities and USDA scientists

8. Probable causes of the increase in Fusarium Head Blight reduced tillage practices susceptible cultivars expanded corn production weather patterns favoring FHB

9. Precipitation Patterns Red River Valley, MN

10. Wheat and Barley Cultivars several very popular wheat cultivars were highly susceptible to FHB these were not tested during their development all malt barley cultivars were moderately susceptible

11. Fusarium Head Blight the increase of FHB has been associated with increased corn production and widespread adoption of reduced tillage practices

12. Hard Red WinterHard Red SpringWhiteSoft Red WinterDurum USA wheat production areas - shown by class - since 2013 irrigated wheat in rotation with corn

13. FHB Pathogens predominance of Fusarium graminearum (Gibberella zeae) as the causal fungus F. culmorum, F. poae, F. avenaceum, F. equiseti, F. acuminatum, F. sporotrichioides, and others

14. Fusarium Head Blight Sporadic epidemics reported in the United States since wheat production was first established From a historical perspective FHB was most effectively controlled from the end of WWII to the mid-1980’s - the era of the moldboard plow -

15. PROGRESS

16. HOST RESISTANCE

17. Phenotyping Inoculated Mist-Irrigated Nurseries Evaluation of FHB response: Identifying susceptible varieties Identifying sources of resistance Screening breeding populations, elite material and commercial cultivars Identifying QTL associated with reduced FHB and mycotoxins

19. Sources of Resistance Evaluation of germplasm collections has identified resistance Sumai 3, Frontana, Freedom, Abura, 16- 52-9, Tokai 66 ‘Native’ resistance has also been identified Truman, Bess, Roane and others

20. Marker Assisted Selection rr RR Rr S1 S2 S3 S4 Funo Sumai 3 CS DT3BL N3AT3D N3DT3A BAC R1 R2 R3 R4 3AS CS 3DS CS 3BS CS, Sumai 3 3DS Sumai 3 Development of diagnostic markers for Fhb1

21. Genotyping Centers Three Regional USDA Labs Goals: develop new molecular marker technologies implement strategies for their application in breeding provide access to MAS technologies maximize the efficiency of small grain breeding programs Traits: quality and disease resistance

22. Marker Assisted Selection Markers used for FHB resistance NameLocationQTL DonorMarker Qfhs.ndsu-3BS3BS T. aestivumXbarc133 Qfhs.ifa-5A5AS T. aestivumXgwm293 Qfhs.ndsu-3AS3AS T. dicoccoidesXgwm2 Qfsh.ndsu-2A2AL T. aestivumXksuH16 Qfhs.ndsu-4BL4BL T. aestivumXwg909

23. Reaction of Wheat Varieties to FHB - 1996

24. Reaction of Wheat Varieties to FHB - 2014

25. Host Resistance – Best Practices avoid highly susceptible cultivars plant varieties with improved resistance diversify - spread in heading dates reduces risk

26. CHEMICAL CONTROL

27. Chemical Control Heading applications - 50-60% reductions in severity  Early to mid 1990’s: mancozeb (protectant) and systemic MBC fungicides (benomyl)  Late 1990’s: Tilt (propiconazole), Folicur (tebuconazole), Quadris (azoxystrobilurin)  2000’s: Caramba (metconazole), Proline (prothioconazole), Prosaro (prothioconazole & tebuconazole) Application technology - nozzle type & direction

28. Chemical Control Heading applications - 50-60% reductions in severity  Early to mid 1990’s: mancozeb (protectant) and systemic MBC fungicides (benomyl)  Late 1990’s: Tilt (propiconazole), Folicur (tebuconazole), Quadris (azoxystrobilurin)  2000’s: Caramba (metconazole), Proline (prothioconazole), Prosaro (prothioconazole & tebuconazole) Application technology - nozzle type & direction associated with increased DON

29. Fungicides – Best Timings www.scabsmart.org

30. Fungicide Spray Angle and Direction

31. Chemical Control – Best Practices recommended fungicides Prosaro, Caramba and Proline – used with an adjuvant apply at early flowering (Feekes 10.51) application technology Ground: twin directional nozzles – increase volume for best coverage Air: use a small droplet size / evening or early morning (dew as additional water)

32. FHB Prediction Models Opportunities: sporadic disease plants vulnerable for short period of time environment impacts the disease cycle

33. Temperature Precipitation Relative humidity Solar radiation Wind Wetness duration Inoculum production Spore liberation Spore dispersal Spore deposition Host infection Host colonization Residue type Survival Perithecia Conidiogenesis Spore maturation Ascopore release Conidia release Inoculum level Inoculum type Rain scrub Aerodynamics Survival Attachment Plant architecture Survival Host reaction Growth stage Anthers Spread within head Growth stage Other hosts Erick DeWolf, Kansas State University FHB Prediction Models

35. weather station

36. ScabSmart www.scabsmart.org

37. CULTURAL CONTROL

38. Residues are problematic as they harbor the initial inoculum from which epidemics develop increased corn acreage is likely the major driver of FHB in much of the world conservation tillage has increased Fusarium survival in host & non-host residues

39. Fusarium Head Blight in regions with extended winters cold reduces microbial resulting in greater inoculum pressure may also be true for regions with a dry period

40. Residue Decomposition Wheat residues support Fusarium as long as they are ‘recoverable’ - up to three cropping seasons Burying residues speeds residue decomposition BUT residues returned to the soil surface support inoculum production F. graminearum one of the earlier colonizers of residues - pathogenic phase may give it a competitive advantage as a saprophyte

41. Crop Residues Wheat residues likely as good a host as corn BUT corn residues persist longer AND Bt-corn may exacerbate this No-till vs reduced tillage differences in residue-moisture interactions

42. Crop Residues Regional, atmospheric spore populations more inoculum than within-field sources (especially under FHB-conducive environments) Within-field inoculum important in FHB-limiting environments but generally less than 30% of the total inoculum Inoculum (debris) management strategies in individual fields may help reduce FHB & DON and contribute to integrated management

43. Host resistance - Fusarium survival Resistance to FHB in wheat influences the colonization of residues (survival and inoculum production) FHB resistance can provide a benefits in future cropping seasons by reducing future inoculum Avoiding the initial colonization of crops is a better option than trying to reduce Fusarium levels in residues

44. Cultural Control – Best Practices Avoid growing wheat in proximity to cereal debris (follow non-host crops) Residue management following epidemic years Plant resistant cereals - reduce Fusarium in debris

45. What is the contribution of individual practices to the management of FHB/DON? no single answer for all environments and cropping systems

46. FHB MANAGEMENT REQUIRES AN INTEGRATED APPROACH

47. Very susceptible cultivars have been eliminated Resistance has been improved – BUT immunity is unrealistic and is not alone sufficient to eliminate risk Chemical control is needed in the management of FHB Improved application technologies and forecasting systems have improved our ability to use fungicides

48. Future Challenges Adoption of varieties with improved FHB resistance Maintaining identity of resistance in some markets Maintaining/improving resistance over the long term Ever increasing corn acreage Limited options for rotations in many production systems Impact of climate change on Fusarium species

49. Acknowledgements Co-Authors: David Van Sanford, University of Kentucky Erick De Wolf, Kansas State University Pierce Paul, The Ohio State University USWBSI Colleagues Gary Bergstrom, Cornell Marcia McMullen, NDSU University of Minnesota James Anderson Robert Busch David Garvin Roger Jones Gary Muehlbauer Albert Sims University of Minnesota Small Grains Pathology Matthew Culler Amar Elakkad C. Kent Evans Pravin Gautam Silvia Pereyra Carlos Perez Bacilio Salas Beheshteh Zargaran