Wheat Diseases and Pests - Wheat Doctor - CIMMYT

Basal Glume Rot
and Bacterial Leaf Blight
Pseudomonas syringae pv. atrofaciens
Syn. Pseudomonas atrofaciens
Symptoms: The leaves, culms, and spikes of v
wheat and triticale can be infected. Infections
begin as small, dark green, water-soaked lesions
that turn dark brown to blackish in color. On the
spikelets, lesions generally start at the base of the
glume and may eventually extend over the entire
glume (51 1. Diseased glumes have a translucent
appearance when held toward the light. Dark
brown to black discoloration occurs with age. The
disease may spread to the rachis, and lesions may
also develop on the kernels (52). Under wet or
humid conditions, a whitish gray bacterial ooze
may be present. Stem infections result in dark
discoloration of the stem; leaf infections result in
small, irregular, water-soaked lesions. Symptoms
can be confused with those of other bacterial
diseases, genetic melanism (false black chaff),
septoria nodorum blotch (glume blotch), and frost
damage.
Development: The pathogen survives on crop
debris, as well as various grass hosts. It is
disseminated by splashing rain or by insects, and
can be seed borne.
Hosts/Distribution: The disease can affect all small
grain cereal crops; distribution is worldwide.
Importance: Basal glume rot usually is not
economically important, but is frequently reported
in humid cereal-growing areas.
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