DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.
Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Bacterial blast
HOST: Pear
The bacterium infects all flower parts and may spread and kill the entire spur.
Bacterial blast | Pear
DISEASE: Bacterial blast
HOST: Pear (Pyrus communis)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: W. Sinclair
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with small, brown spots.
Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Goto
DISEASE: Bacterial leaf spot
HOST: Zinnia
Leaf with blackish, necrotic, angular spots.
Bacterial leaf spot | Zinnia
DISEASE: Bacterial leaf spot
HOST: Zinnia (Zinnia violacea)
PATHOGEN: Xanthomonas campestris pv. zinniae
SOURCE: M. Daughtrey
DISEASE: Bunch disease (Witches'-broom)
HOST: Butternut
Bunch disease of butternut.
Bunch disease (Witches'-broom) | Butternut
DISEASE: Bunch disease (Witches'-broom)
HOST: Butternut (Juglans cinerea)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: Crown gall
HOST: Pear
Crown gall of pear rootstock.
Crown gall | Pear
DISEASE: Crown gall
HOST: Pear (Pyrus communis)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: H. Sawada, M. Goto
DISEASE: Fire blight
HOST: Pear
Blighted shoot and blossoms.
Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Fire blight
HOST: Pear
Typical appearance of advanced stage of disease after the bacterium invades from shoot tips/flowers downward.
Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Fire blight
HOST: Pear
The disease causes lack of leaf detachment on infected branches, commonly seen during California winters.
Fire blight | Pear
DISEASE: Fire blight
HOST: Pear (Pyrus communis)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth