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 stem rot
HOST: Tomato
Stem with long necrotic lesions. The pathogen often enters plants following pruning injuries.

Bacterial stem rot | Tomato
DISEASE: Bacterial stem rot
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Ewinia carotovora subsp. atroseptica
SOURCE: A. Alvarez
DISEASE: Bacterial stem rot
HOST: Tomato
Wilt is first symptom of disease. Later, the pith usually disintegrates, causing hollow and blackened stems.

Bacterial stem rot | Tomato
DISEASE: Bacterial stem rot
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: M. Stanghelllini
DISEASE: Bacterial wilt
HOST: Alfalfa
Longitudinal section of defined brown gum pockets on inner surface of root bark.

Bacterial wilt | Alfalfa
DISEASE: Bacterial wilt
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Clavibacter michiganensis subsp. insidiosus
SOURCE: S. Thomson
DISEASE: Bacterial wilt
HOST: Alfalfa
Infected plant (left) with typical symptoms of stunting and chlorosis. Other characteristic symptoms are spindly stems and small distorted leaflets. Healthy plant (right).

Bacterial wilt | Alfalfa
DISEASE: Bacterial wilt
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Clavibacter michiganensis subsp. insidiosus
SOURCE: S. Thomson
DISEASE: Bacterial wilt
HOST: Alfalfa
Diseased plant with chlorotic leaves.

Bacterial wilt | Alfalfa
DISEASE: Bacterial wilt
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Clavibacter michiganensis subsp. insidiosus
SOURCE: S. Thomson
DISEASE: Bacterial wilt
HOST: Alfalfa
Cross sections of diseased roots with defined brown gum pockets on inner surface of bark. Healthy root (upper left). Other sections represent increases in disease severity.

Bacterial wilt | Alfalfa
DISEASE: Bacterial wilt
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Clavibacter michiganensis subsp. insidiosus
SOURCE: L. Claflin
DISEASE: Blackleg
HOST: Potato
Black, elongated necrotic areas, characteristic of stem rot.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: S. Mohan