Stategic Planning for Mitigation of Fusarium Head Blight in...
Transcript of Stategic Planning for Mitigation of Fusarium Head Blight in...
One University. Many Futures.
Stategic Planning for Mitigation of Fusarium Head
Blight in Wheat
Anita Brûlé-BabelDepartment of Plant Science
• Prior to 1980 FHB epidemics were sporadic
• Since early 1980’s in Ontario and early 1990’s in Manitoba severe FHB epidemics have occurred more frequently
• Recent increase in Saskatchewan and Alberta
• Losses in yield and end-use quality • Mycotoxin contamination affects food and
feed safety, and reduces grain marketability
• Losses to Canadian wheat industry in excess of $1 billion (Clear et al. 2009)
FHB Issue
Symptoms
Premature bleaching
White, pinkor orange spores
Fusarium damaged kernels
Source: Trail, 2009
Conidia - disperse over short distances
Ascospores- primary inoculum - can travel kilometers
Multiple Species• Fusarium graminearium
– Main species of concern in Eastern Canada, Manitoba and Southeast Saskatchewan
– Produces primarily deoxynivalenol (DON) • F. culmorum
– Adapted to cooler conditions – Produces primarily deoxynivalenol (DON)
• F. avenaceum– Produces primarily moniliformin (MON)
• F. poae– Produces nivalenol (NIV) and other toxins
• Septoria nodorum– Symptoms may be confused with FHB
• Other species and toxins also present in low amounts
Disease Triangle Influences Management Strategy
• All components of disease triangle required for disease to occur
Disease
Environment
Most Susceptible Stage• Flowering (Anthesis)• Need warm, moist
conditions– Precipitation– 16 to 32 oC– Night temperature
above 10 oC– High humidity
• Infection possible to soft dough stage– May not see same
symptoms but mycotoxins may be present
http://www.gov.mb.ca/agriculture/crops/seasonal-reports/fusarium-head-blight-risk-forecast-archives.html
FHB Risk Forecast
Based mainly on conditions suitable for F. graminearumDuration of rainfall (hours) and temperatures between 15 and 30 C for 7 days prior to anthesis
How can I manage risk of FHB infection?
A. Spread out planting datesB. Use practices that promote uniform
stands (i.e. all plants/spikes at same stage)
C. Neither A nor BD. Both A and BE. Don’t know
Disease Triangle Influences Management Strategy
• All components of disease triangle required for disease to occur
Disease
Environment
www.seedmb.ca
http://www.seedmb.ca/digital-edition
• Screening nurseries under uniform conditions used todetermine FHB resistance level
• Comparisons made with known checks• DON also considered in evaluation
FHB Rating –Disease Symptoms
● Rating for incidence and severity 18-21 days after first inoculation
● Incidence is percent of infected spikes in 1-m-row plot
● Severity is percent of infected spikelets on individual spikes
● FHB Index = Incidence*Severity/100
Choosing a MR variety is the only management tool I need to control
FHBA. TrueB. False
What does a rating of MR mean?
2010 FHB INDEX SCALEFOR SPRING WHEAT
COOP TESTSR <9.0MR 9.1-20.0I 20.1-30.0MS 30.1-45.0S >45.1
Resistance alone is not sufficient.
Disease Triangle Influences Management Strategy
• All components of disease triangle required for disease to occur
Disease
Environment
Fungicides
• Consider FHB risk forecast • Suppressive – do not provide complete
control• Timing of application critical (flowering)• Application technology
– Configuration of sprayer nozzles to ensure proper application
• Best results when combined with more resistant varieties
Fungicide Efficacy with Cultivar (High Disease Pressure)
Fungicide Glenn (MR-I) Roblin (S)FHB
IndexFDK DON FHB
IndexFDK DON
Prosaro 93.6 55.6 73.1 12.3 -4.3 -20.4Proline 97.9 67.5 69.9 21.9 11.3 13.6Folicur 90.2 51.0 64.3 22.8 -2.4 23.6Caramba 95.7 57.9 70.3 6.8 -6.8 10.0
% reduction in FHB index, FDKand DON highest with more resistant cultivar
Amarasinghe 2011
Prosaro = tebuconozole + prothioconazole; Proline = prothioconazole; Folicur = tebuconozole; Caramba = metconazole (all triazoles)
Interaction Between Variety and Fungicide Treatment
• Four site-years• Treatments
– FHB Inoculate – untreated– FHB Inoculated + Seed Fungicide (Crusier Maxx®
Cereals)– FHB Inoculated + Foliar Fungicide (Prosaro 250EC ®)– FHB Inoculated + Seed + Foliar Fungicide– Uninoculated – untreated
• Varieties– Spring – Carberry (MR), Harvest (S)– Winter - Emerson (R), CDC Falcon (S)
0
5
10
15
20
25
30D
ON
(ppm
)
Carberry(MR) Emerson (R) CDC-Falcon (S)Harvest (S)
c c cc
Effect on DON
aa
a a
bb
b bb b
aab
bb
a a
0
1
2
3
4
5
6
Yiel
d (t/
ha)
Harvest (S)Carberry (MR) Emerson (R) CDC-Falcon (S)
Effect on Yield
a a
a a
bb b b
cc a
b b b
c
a
cd
abbc
Other Management Strategies
• Seed quality (Seedling blight vs Head blight)
• Crop rotation – away from cereals and grasses
• Residue management – promote rapid decomposition of residues
• Harvest management and storage –combine settings and moisture content
Seed Quality
• Fusarium infected seed does not directly lead to FHB (Gilbert et al, 2003) – Seedling blight and head blight are not the
same• FHB infected seed will affect seedling
vigour, plant stands, and crop uniformity• Recommendation to use healthy seed
where possible (regulations differ between provinces)
Crop Rotation• F. graminearum survives saprophytically
on crop residues– Corn, small grain cereals such as wheat and
barley• Avoid corn-wheat, wheat-wheat, barley-
wheat rotations• Rotate wheat with non-susceptible crops
– Length of rotation depends on rate of decomposition of crop residues
Residue Management
• Tillage – burying FHB infested crop residues reduces inoculum
• Burning• Chop crop residues in smaller pieces so
they degrade faster• Remove crop residues• Ascospores can travel large distances
– Good local practices may not be enough under conditions that favour the disease
Harvest Management
• Allowable FDK ranges from 0.25% to 4% by weight depending on class and grade
• Increased fan speed and shutter opening could reduce FDK (Salgado et al 2011, 2014)
• If infection is not uniform –harvest areas separately
• Make sure grain is dry in storage Note: FDK and DON are
not always highly correlated.
Summary• FHB management is complex• Variety resistance is not complete• Fungicides are suppressive only• Pay attention to environmental conditions at
critical times• Resistance plus other management practices
are essential
Acknowledgements• People
– Dilantha Fernando– Jeannie Gilbert– Brian Beres– Mary Meleshko– Eppie Austria– Roger Larios– Maria Stoimenova– Chami Amarasinghe– Zesong Ye– Numerous summer students
• Funding– WGRF– NSERC– Husky Energy– CWB– ARDI– ACIDF– AAFC