DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.
Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial fruit blotch
HOST: Watermelon
Symptoms of external disease of mature watermelon.
Bacterial fruit blotch | Watermelon
DISEASE: Bacterial fruit blotch
HOST: Watermelon (Citrullus lanatus)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: R. X. Latin
DISEASE: Bacterial fruit blotch
HOST: Watermelon
Diseased watermelon with copious white foam.
Bacterial fruit blotch | Watermelon
DISEASE: Bacterial fruit blotch
HOST: Watermelon (Citrullus lanatus)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf and stem necrosis
HOST: Watermelon
Seedlings with necrotic leaves and water-soaked stems.
Bacterial leaf and stem necrosis | Watermelon
DISEASE: Bacterial leaf and stem necrosis
HOST: Watermelon (Citrullus lanatus)
PATHOGEN: Pseudomonas viridiflava
SOURCE: Y. Aysan
DISEASE: Bacterial wilt
HOST: Squash
Field with severe symptoms of wilt. Foliage often is chlorotic and leaf margins may be chlorotic and necrotic before plant death. Bacterial ooze may be seen streaming from the xylem when infected stems are cut.
Bacterial wilt | Squash
DISEASE: Bacterial wilt
HOST: Squash (Cucurbita maxima)
PATHOGEN: Erwinia tracheiphila
SOURCE: B. Jacobsen, M. Shurtleff
DISEASE: Cane blight
HOST: Rose
Rose with blighted necrotic cane.
Cane blight | Rose
DISEASE: Cane blight
HOST: Rose (Rosa sp.)
PATHOGEN: Pseudomonas syringae
SOURCE: S. Mohan
DISEASE: Crown gall
HOST: Rose
Rose with galls near soil line.
Crown gall | Rose
DISEASE: Crown gall
HOST: Rose (Rosa sp.)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: M. Goto
DISEASE: Hairy root
HOST: Rose
Hairy root symptoms of many fibrous roots (right). Noninfected root (left).
Hairy root | Rose
DISEASE: Hairy root
HOST: Rose (Rosa sp.)
PATHOGEN: Agrobacterium rhizogenes
SOURCE: R. Raabe
DISEASE: Hairy root
HOST: Rose
Crown gall (left) and hairy root (right) caused by Agrobacterium tumefaciens and A. rhizogenes, respectively. Healthy root (center).
Hairy root | Rose
DISEASE: Hairy root
HOST: Rose (Rosa sp.)
PATHOGEN: Agrobacterium rhizogenes
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: M. Schroth