Wheat Disease
Identification 2008
Clayton A. Hollier
Department of Plant Pathology and Crop Physiology
Wheat Disease Identification 2008
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Stripe Rust
Leaf rust
Stem rust
Stagonospora leaf blight/glume blotch
Bacterial streak/black chaff
Wheat Disease Identification 2008
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Stripe rust (yellow rust)
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Cool season rust (disease development most rapid
between 40 to 59F)
Pustules appear on foliage producing long yellow
stripes.
Increasing in its importance to Louisiana wheat?
Stripe rust, wheat
Wheat Disease Identification 2008
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Leaf rust
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Develops best during moderate temperatures (6080F)
Many races (changes or shifts quite readily)
Four 10-day cycles are all that is necessary for
rust to develop from a few pustules to an
epidemic.
Leaf rust, wheat
Wheat Disease Identification 2008
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Stem rust
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“Hot” season rust (79-104F)
Very destructive in scattered locations within the
field, but overall damage is very light statewide.
Rarely needs fungicide application.
Stem rust, wheat
Wheat Disease Identification 2008
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Leaf and glume blotch
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Pathogen survives on crop residue
Works from bottom of plant upward
Spreads easily by splashing water
Is confused with other foliar and head diseases
(bacterial streak, tan spot, black chaff)
Leaf blotch, wheat
Glume blotch, wheat
Black chaff, wheat
Tan spot, wheat