DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
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
DISEASE: Blackleg
HOST: Potato
Black necrotic stem; late stage of disease.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: S. Mohan
DISEASE: Blackleg
HOST: Potato
Infected stem with brown necrotic symptoms.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: R. Rowe
DISEASE: Blackleg
HOST: Potato
Stems with severe blackleg symptoms.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: A. Paulus, M. Shurtleff
DISEASE: Blackleg
HOST: Potato
Diseased plant with stunted, yellowish foliage.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: M. Shurtleff
DISEASE: Blackleg
HOST: Potato
Blackleg-infected tubers.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: S. De Boer
DISEASE: Blackleg
HOST: Potato
Young wilted plant with discolored leaves and necrosis of stems at ground level.

Blackleg | Potato
DISEASE: Blackleg
HOST: Potato (Solanum tuberosum)
PATHOGEN: Pectobacterium atrosepticum
PATHOGEN SYNONYM: Erwinia carotovora subsp. atroseptica
SOURCE: L. Claflin
DISEASE: Syringae leaf spot
HOST: Tomato
Leaves with brown necrotic lesions and chlorotic margins. Symptoms vary greatly among cultivars. Some have black or brown lesions with bright yellow, chlorotic areas and others do not have yellowing.

Syringae leaf spot | Tomato
DISEASE: Syringae leaf spot
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: R. Gitaitis