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 leaf blight and rot
HOST: Orchid
Leaves of Dendrobium orchid with necrosis, discoloration, and rot.

Bacterial leaf blight and rot | Orchid
DISEASE: Bacterial leaf blight and rot
HOST: Orchid (Dendrobium sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: L. Keith
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 and rot
HOST: Orchid
Orchid hybrid (Odontoglossum × Memoria Martin Orenstein 'Lulu') with large, brown, infected area on leaves with water-soaking at margin between healthy and diseased tissues.

Bacterial leaf blight and rot | Orchid
DISEASE: Bacterial leaf blight and rot
HOST: Orchid (Odontoglossum sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: L. Keith
DISEASE: Bacterial leaf blight and rot
HOST: Orchid
Orchid hybrid (Vuyl × Melissa Brianne 'Kai's Choice') with diseased leaves.

Bacterial leaf blight and rot | Orchid
DISEASE: Bacterial leaf blight and rot
HOST: Orchid (Vuylstekeara sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: L. Keith
DISEASE: Halo blight
HOST: Bean
Chlorotic, systemic symptoms with necrotic lesions on leaves of 'Romano' common bean.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus vulgaris 'Romano')
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: M. Schroth
DISEASE: Halo blight
HOST: Bean
Leaf of 'Bountiful' bean with chlorotic halos, an early stage of disease. Tiny water-soaked are difficult to see.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus vulgaris 'Bountiful')
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: M. Schroth
DISEASE: Halo blight
HOST: Bean
Common bean with systemic chlorosis and distorted leaves.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: A. Hayward
DISEASE: Halo blight
HOST: Bean
Leaves of highly susceptible 'Red Kidney' dry bean with typical water-soaked lesions with halos.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus vulgaris 'Red Kidney')
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: M. Goto