DISEASE: Aster yellows
HOST: Barley
Infection by this phytoplasm causes twisted awns and sterile florets.

Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
DISEASE: Aster yellows
HOST: Barley
Small necrotic spots on lower leaves and red coalescing streaks on upper leaves.

Aster yellows | Barley
DISEASE: Aster yellows
HOST: Barley (Hordeum vulgare)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Banttari
DISEASE: Bacterial bud and petal blight
HOST: Orchid
Miltonia orchid with brownish necrotic areas around edges of flower petals.

Bacterial bud and petal blight | Orchid
DISEASE: Bacterial bud and petal blight
HOST: Orchid (Miltonia sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial bud and petal blight
HOST: Orchid
Miltonia orchid with diseased water-soaked flower buds.

Bacterial bud and petal blight | Orchid
DISEASE: Bacterial bud and petal blight
HOST: Orchid (Miltonia sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial kernel blight (Leaf blight)
HOST: Barley
Dark, brown discolored kernels at the embryo end and posterior surface.

Bacterial kernel blight (Leaf blight) | Barley
DISEASE: Bacterial kernel blight (Leaf blight)
HOST: Barley (Hordeum vulgare)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: C. Martinez-Miller
DISEASE: Bacterial leaf blight and rot
HOST: Orchid
Orchid hybrid (Miltonia × Bert Field 'Eileen') with water-soaked, discolored area near base of leaf.

Bacterial leaf blight and rot | Orchid
DISEASE: Bacterial leaf blight and rot
HOST: Orchid (Miltonia sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: L. Keith
DISEASE: Bacterial leaf blight
HOST: Barley
Diseased barley plants with typical bleaching of flag leaves. Initial symptoms are water-soaked lesions that later coalesce. Eventually, the entire leaf becomes necrotic and edges roll inward.

Bacterial leaf blight | Barley
DISEASE: Bacterial leaf blight
HOST: Barley (Hordeum vulgare)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: D. Sands
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley
Black chaff is characterized by water-soaked and darkened glumes on barley heads and streaks and stripes on leaves.

Black chaff (Bacterial leaf streak) | Barley
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley (Hordeum vulgare)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: S. Thomson
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley
Leaf with linear, water-soaked lesions that turn necrotic and brown. Flakes of dry bacterial exudate are apparent on the lesions. The pathogen also causes black glume of barley.

Black chaff (Bacterial leaf streak) | Barley
DISEASE: Black chaff (Bacterial leaf streak)
HOST: Barley (Hordeum vulgare)
PATHOGEN: Xanthomonas translucens pv. undulosa
SOURCE: S. Thomson