DISEASE: Aster yellows
HOST: Marigold
Infected plant (left) with yellowing and stunting.

Aster yellows | Marigold
DISEASE: Aster yellows
HOST: Marigold (Tagetes erecta)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: M. Shurtleff
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: Pseudomonas leaf spot
HOST: Marigold
Marigolds with yellow apical chlorosis attributed to toxin production by the pathogen.

Pseudomonas leaf spot | Marigold
DISEASE: Pseudomonas leaf spot
HOST: Marigold (Tagetes erecta)
PATHOGEN: Pseudomonas syringae pv. tagetis
SOURCE: R. Durbin
DISEASE: Pseudomonas leaf spot
HOST: Marigold
Chlorotic leaves with total loss of chlorophyll. Disease is also known as toxic chlorosis.

Pseudomonas leaf spot | Marigold
DISEASE: Pseudomonas leaf spot
HOST: Marigold (Tagetes erecta)
PATHOGEN: Pseudomonas syringae pv. tagetis
SOURCE: R. Durbin
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