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 streak and bulb rot
HOST: Onion
The disease is characterized by dark spots on wrapper scales and/or reddish brown discoloration of inner scales.
Bacterial leaf streak and bulb rot | Onion
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas viridiflava
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion
Onion with dead and rotted leaf at base of stem. Typical symptoms are water-soaked, dark green lesions that become oval with time, along with streaks and tipburn.
Bacterial leaf streak and bulb rot | Onion
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas viridiflava
SOURCE: H. Schwartz
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion
Browning and decay of bulb following inoculation with Pseudomonas viridiflava.
Bacterial leaf streak and bulb rot | Onion
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas viridiflava
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion
Close-up of diseased leaves.
Bacterial leaf streak and bulb rot | Onion
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas viridiflava
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion
Bulb rot with gray, bluish symptoms. Reddish brown discolorations also may occur.
Bacterial leaf streak and bulb rot | Onion
DISEASE: Bacterial leaf streak and bulb rot
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas viridiflava
SOURCE: R. Gitaitis
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