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 blight
HOST: Photinia
Symptoms of photinia bud blight shown here are similar to those of blast of pear and apple, caused by Pseudomonas syringae pv. syringae.
Bacterial blight | Photinia
DISEASE: Bacterial blight
HOST: Photinia (Photinia glabra)
PATHOGEN: Pseudomonas syringae pv. photiniae
SOURCE: M. Goto
DISEASE: Bacterial stem and root rot
HOST: Sweet potato
Collapse of stems and roots caused by systemic activity of the pathogen.
Bacterial stem and root rot | Sweet potato
DISEASE: Bacterial stem and root rot
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: N. Schaad
DISEASE: Bacterial stem and root rot
HOST: Sweet potato
Rot and collapse of stem, petioles, and leaves caused by systemic infection.
Bacterial stem and root rot | Sweet potato
DISEASE: Bacterial stem and root rot
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: N. Schaad
DISEASE: Bacterial stem and root rot
HOST: Sweet potato
Rot and internal discoloration of tuber.
Bacterial stem and root rot | Sweet potato
DISEASE: Bacterial stem and root rot
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: C. Clark
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: Fire blight
HOST: Photinia
Fire blight cankers on photinia.
Fire blight | Photinia
DISEASE: Fire blight
HOST: Photinia (Photinia fraseri)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Fire blight
HOST: Photinia
Typical crook neck symptom of infected shoot.
Fire blight | Photinia
DISEASE: Fire blight
HOST: Photinia (Photinia fraseri)
PATHOGEN: Erwinia amylovora
SOURCE: M. Schroth
DISEASE: Sweet potato little leaf
HOST: Sweet potato
Infected plant (left) and healthy plant (right).
Sweet potato little leaf | Sweet potato
DISEASE: Sweet potato little leaf
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: 'Candidatus Phytoplasma aurantifolia'
PATHOGEN SYNONYM: Phytoplasma Peanut witches'-broom group
SOURCE: R. McCoy, M. Davis