DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.

Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet
Cross section of sugar beet with reddish color in vascular bundles and adjacent tissues.

Bacterial vascular necrosis and rot | Beet
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet (Beta vulgaris)
PATHOGEN: Pectobacterium betavasculorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. betavasculorum
SOURCE: M. Schroth
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet
Advanced stage of disease with extensive rot.

Bacterial vascular necrosis and rot | Beet
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet (Beta vulgaris)
PATHOGEN: Pectobacterium betavasculorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. betavasculorum
SOURCE: M. Schroth
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet
Early stage of systemic infection of young plant noted by blackening of midribs and veins.

Bacterial vascular necrosis and rot | Beet
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet (Beta vulgaris)
PATHOGEN: Pectobacterium betavasculorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. betavasculorum
SOURCE: M. Schroth
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet
Infected vascular bundles caused by systemic infection by the bacterium.

Bacterial vascular necrosis and rot | Beet
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet (Beta vulgaris)
PATHOGEN: Pectobacterium betavasculorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. betavasculorum
SOURCE: S. Thomson
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet
Black discoloration of petioles resulting from systemic infection.

Bacterial vascular necrosis and rot | Beet
DISEASE: Bacterial vascular necrosis and rot
HOST: Beet (Beta vulgaris)
PATHOGEN: Pectobacterium betavasculorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. betavasculorum
SOURCE: S. Thomson
DISEASE: Multiplier disease
HOST: Strawberry
Multiplier disease causes production of numerous crowns along runners.

Multiplier disease | Strawberry
DISEASE: Multiplier disease
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: M. Clark
DISEASE: Witches'-broom
HOST: Alfalfa
Alfalfa plant (center) exhibiting stunting and proliferation of stems. Other symptoms are small, rounded, chlorotic, often puckered leaves and a yellowish cast.

Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Young plant (left) with small, numerous stems (witches'-broom). Healthy stems (right).

Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson