Wheat Diseases and Management ver' 2003

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Wheat Diseases and Management
ver. 2003

• Martin Draper
• Extension Plant Pathologist

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disease
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epidemic
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Residue-borne Diseases
Tan spot
Septoria blotch
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• Residue-borne Diseases
• Tan spot
• Septoria complex
• Both diseases were common, but delayed and
  generally not severe in 2003
• Rusts in 2003
• Stem rust (rare)
• Leaf rust
• Stripe rust

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Stem rust
Leaf rust
Stripe rust
Day 60-70ºF Night
50-60ºF Dew yes Lose viability above 80ºF
Day 77-86ºF Night 59-68ºF Dew yes
Day 68-77ºF Night 59-68ºF Dew yes
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US Wheat Production
Windborne Rust Spores
Rust Puccinia Pathway
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June 13 Davison, Lyman Co.
June 20 Brown (SW)
June 3 Stanley Co.
May 30 - Brookings
June 9 Douglas Co.
June 1 SE NE
May 15 KS
Stripe Rust 2003
Windborne Rust Spores
Rust Puccinia Pathway
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• Moderately resistant reaction
• Winter Wheat
• Wesley
• Alliance
• CDC Falcon
• Crimson
• Jagalene

• Spring Wheat
• Dapps
• Ingot
• NorPro
• Oxen
• Reeder

• Jagger
• Jerry
• Millennium
• Tandem
• Wahoo

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• Moderately susceptible reaction
• Winter Wheat
• 2137
• Arapahoe
• Expedition
• Harding
• TAM 107
• NuPlains (white)

• Spring Wheat
• Forge
• Granite
• Hanna
• Knudson

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• Susceptible reaction
• Winter Wheat
• Nekota
• Trego
• Hondo

• Spring Wheat
• Walworth

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• Considerations
• Winter wheat crop location
• Crop is planted in wheat or corn residue
• History has shown potential for damaging levels
  of disease in a given field
• Disease severe on lower leaves at jointing stage
• Extended wet weather is forecast soon after
  jointing
• The yield potential is 45-50 bu/A

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Critical Protection Point
High Impact
Pathogen Detection
Amount of Disease ()
Economic Threshold
Low Impact
Time (weeks)
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• When to apply fungicide
• Seedling crop with post-herbicide
• Only if recropped in wheat residue
• Flag leaf emergence-head emergence
• If disease is appearing on Flag-1 or Flag-2
• If variety is leaf disease susceptible (rust or
  others)
• Flowering
• If scab risk exists
• If late season disease pressure from rusts

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• Foliar wheat fungicides available in SD
• mancozeb products (3.50/lb) (1-2 lb/A)
• Dithane (DF Rainshield, F-45 Rainshield, M-45),
  Penncozeb (75 DF, 80 WP)
• Manzate (75 DF, 80 WP)
• Manex Manex II
• propiconazole (2.50/fl oz)
• Tilt, PropiMax EC, Bumper (2-4 fl oz/A)
• azoxystrobin (2.00/fl oz)
• Quadris (6.2-10.8 fl oz/A)
• pyraclostrobin (1.50/fl oz)
• Headline (6-9 fl oz/A)
• azoxystrobin propiconazole (?)
• Quilt (?)
• trifloxystrobin propiconizole (1.25/fl oz)
• Stratego (5-10 fl oz/A)
• tebuconazole (2.50/fl oz)
• Folicur (4 fl oz/A)

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Stripe Rust
Total leaf disease
Leaf Rust
Cultivar - 2137 Hazel, SD - 2003
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With Herbicide
Flag leaf treatment
Heading
Combination treatments
Cultivar 2137 Hazel, SD, 2003
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• Yield - 2003?
• Hazel location?
• No significant increase in yield
• Other trial sites?
• Increased HRSW yield at Groton
• No effect on HRSW at NE Farm (Watertown)
• Increased HRSW yield at Brookings (artificial
  environment)
• Douglas County producers fields
• 40 bu/A untreated vs 60 bu/A Tilt treated
  Arapahoe

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• Integrated management
• Tan spot/Septoria
• Rotation
• Tillage
• Host resistance
• Fungicides
• Rusts
• Host resistance
• Fungicides

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• Costs vs. Benefits
• Potential yield increase
• Stripe rust response can be up to 30 - 20 bu/A
  in some SD fields (Douglas Co.) in 2003
• Wheat leaf disease suppression alone is typically
  5-10 bu/A

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• Costs vs Benefits
• Costs of treatment?
• Up to 20/A for some products-rates
• Most full rate foliar applications 1000/A
• Application costs included to 750/A
• In the face of risk
• generally a good decision!

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• Yield - 2003?
• Hazel location?
• No significant increase in yield
• Other trial sites?
• Increased HRSW yield at Groton
• No effect on HRSW at NE Farm (Watertown)
• Increased HRSW yield at Brookings (artificial
  environment)
• Douglas County producers fields
• 40 bu/A untreated vs 60 bu/A Tilt treated
  Arapahoe

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• Information starts to flow in about January
• Stem rust
• Only an issue on 2137 HRWW
• Leaf rust
• Will continue to be problematic on both HRWW and
  HRSW
• Races continue to sort out
• Stripe rust
• Overwinters in TX and LA
• Completely weather dependent
• In southern states (winter)
• In South Dakota (summer)

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• Rust risk
• Leaf rust
• Warm weather rust
• Highs in the 80s
• Lows in the 60s-80s
• 4-8 hr dew period
• Stripe rust
• Cool weather rust
• Highs in the 70s
• Lows in the 50s and 60s
• Short dew period

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• Will Stripe rust be severe in 2004?
• Maybe!
• Maybe not!
• Dependent on
• Inoculum
• Weather
• Cultivar
• Management
• Current situation in Texas Stripe rust is
  overwintering

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For further information

• http//plantsci.sdstate.edu/planthealth/