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: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis
DISEASE: Xanthomonas wilt
HOST: Banana
Cross sections exposing discoloration of infected fruit.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen
DISEASE: Xanthomonas wilt
HOST: Banana
Sliced diseased stem exposing discolored vascular tissues and bacterial ooze.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen
DISEASE: Xanthomonas wilt
HOST: Banana
Longitudinal sections of fruit exposing brownish red diseased tissues.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen
DISEASE: Xanthomonas wilt
HOST: Banana
Banana stem with discoloration of vascular bundles and bacterial ooze.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen