DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.
Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
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: Apple
Crown gall (left) and hairy root (right) caused by Agrobacterium tumefaciens and A. rhizogenes, respectively.
Hairy root | Apple
DISEASE: Hairy root
HOST: Apple (Malus domestica)
PATHOGEN: Agrobacterium rhizogenes
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: APS
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
DISEASE: Multiplier disease
HOST: Strawberry
Multiplier disease causes production of numerous crowns along runners.
Multiplier disease | Strawberry
DISEASE: Multiplier disease
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: M. Clark
DISEASE: Witches'-broom
HOST: Alfalfa
Alfalfa plant (center) exhibiting stunting and proliferation of stems. Other symptoms are small, rounded, chlorotic, often puckered leaves and a yellowish cast.
Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Young plant (left) with small, numerous stems (witches'-broom). Healthy stems (right).
Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson