DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce
Leaf with black, greasy spots that tend to be vein delimited. Lesions begin as small, angular, water-soaked lesions that coalesce, resulting in large necrotic areas.
![](/sites/default/files/plant_disease/images/0506.jpg)
Bacterial leaf spot (Head rot) | Lettuce
DISEASE: Bacterial leaf spot (Head rot)
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Xanthomonas axonopodis pv. vitians
PATHOGEN SYNONYM: Xanthomonas campestris pv. vitians
SOURCE: A. Alvarez
DISEASE: Bacterial wilt
HOST: Heliconia
Wilted and dying heliconia plant.
![](/sites/default/files/plant_disease/images/0466.jpg)
Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Heliconia
Heliconia spathes with wilt and leaf necrosis.
![](/sites/default/files/plant_disease/images/0467.jpg)
Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Heliconia
Heliconia stalk with discolored base.
![](/sites/default/files/plant_disease/images/0468.jpg)
Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Bacterial wilt
HOST: Heliconia
Spathe of heliconia infected with bacterial wilt (right) compared with healthy spathe.
![](/sites/default/files/plant_disease/images/0469.jpg)
Bacterial wilt | Heliconia
DISEASE: Bacterial wilt
HOST: Heliconia (Heliconia sp.)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: I. Buddenhagen
DISEASE: Corky root
HOST: Lettuce
Corky root causes a reduction in size of lettuce heads and root systems; susceptible cultivar (right) and resistant cultivar (left).
![](/sites/default/files/plant_disease/images/0502.jpg)
Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: E. J. Ryder
DISEASE: Corky root
HOST: Lettuce
Close-up of root with malformed, corky appearance and longitudinal ridges of brown tissues.
![](/sites/default/files/plant_disease/images/0503.jpg)
Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: A. van Bruggen
DISEASE: Corky root
HOST: Lettuce
Initial symptoms of disease are yellow lesions on taproot and main laterals. Greenish brown bands occur around roots. Root pith may become brown and hollow.
![](/sites/default/files/plant_disease/images/0504.jpg)
Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: A. van Bruggen
DISEASE: Corky root
HOST: Lettuce
Differences in corky root symptoms between susceptible cultivar (right) and resistant cultivar (left).
![](/sites/default/files/plant_disease/images/0505.jpg)
Corky root | Lettuce
DISEASE: Corky root
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Sphingomonas suberifaciens
PATHOGEN SYNONYM: Rhizomonas suberifaciens
SOURCE: E. Ryder