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