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: Bacterial brown spot
HOST: Bean
Bean with water-soaked and necrotic lesions on pods and leaves.

Bacterial brown spot | Bean
DISEASE: Bacterial brown spot
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: H. Schwartz
DISEASE: Bacterial brown spot
HOST: Bean
Common bean with necrotic lesions on upper and lower surfaces of leaves. Lesions often are surrounded by bright yellow zones (not shown).

Bacterial brown spot | Bean
DISEASE: Bacterial brown spot
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: H. Schwartz
DISEASE: Bacterial brown spot
HOST: Bean
Leaves of common bean with shot-holes, a late stage of disease.

Bacterial brown spot | Bean
DISEASE: Bacterial brown spot
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: H. Schwartz
DISEASE: Bacterial brown spot
HOST: Bean
Leaves of dwarf bean exhibiting late stage of disease.

Bacterial brown spot | Bean
DISEASE: Bacterial brown spot
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Young
DISEASE: Bacterial brown spot
HOST: Mallotus
Leaf with small, rustylike lesions.

Bacterial brown spot | Mallotus
DISEASE: Bacterial brown spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Xanthomonas campestris pv. malloti
SOURCE: M. Goto
DISEASE: Bacterial brown spot
HOST: Mallotus
Leaf with tiny, light brown spots surrounded by chlorotic zones.

Bacterial brown spot | Mallotus
DISEASE: Bacterial brown spot
HOST: Mallotus (Mallotus japonicus)
PATHOGEN: Xanthomonas campestris pv. malloti
SOURCE: M. Kobayashi, M. Goto
DISEASE: Foamy canker
HOST: Almond
White, macerated tissues near cambium region is characteristic of disease. Foam is usually associated with cankers. The disease is suspected to be bacterial but the causal agent has not been identified.

Foamy canker | Almond
DISEASE: Foamy canker
HOST: Almond (Prunus dulcis)
PATHOGEN: Causal agent unknown
SOURCE: B. Teviotdale