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 leaf spot
HOST: Schefflera
Leaf with water-soaked lesions.
Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: M. Gleason
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with large, grayish necrotic areas.
Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera actinophylla)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase
DISEASE: Bacterial leaf spot
HOST: Schefflera
Leaf with many small, pinpoint-sized lesions and a few large lesions.
Bacterial leaf spot | Schefflera
DISEASE: Bacterial leaf spot
HOST: Schefflera (Schefflera arboricola)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: A. Chase
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: Olive knot
HOST: Olive
Multiple infections of young stems. The bacterium invades vascular tissues during certain times of the year and may be isolated from branches that appear healthy.
Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth
DISEASE: Olive knot
HOST: Olive
Tree with knots/galls on branches along with twig dieback, which is associated with knots. Fusarium and Diplodia spp. infect through knots and are thought to be main reason for dieback.
Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth
DISEASE: Olive knot
HOST: Olive
Multiple infections on olive branch. Knots at this stage begin to die from the outside in and are infected by several fungi.
Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth