DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
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 black spot
HOST: Mango
Mango fruit with oozing lesion (A) and raised, black lesions (B).

Bacterial black spot | Mango
DISEASE: Bacterial black spot
HOST: Mango (Mangifera indica)
PATHOGEN: Xanthomonas campestris pv. mangiferaeindicae
SOURCE: R. Ploetz
DISEASE: Bacterial black spot
HOST: Mango
Mango branch with cankers.

Bacterial black spot | Mango
DISEASE: Bacterial black spot
HOST: Mango (Mangifera indica)
PATHOGEN: Xanthomonas campestris pv. mangiferaeindicae
SOURCE: R. Ploetz
DISEASE: Bacterial black spot
HOST: Mango
Leaf with blackish spots delimited by veins.

Bacterial black spot | Mango
DISEASE: Bacterial black spot
HOST: Mango (Mangifera indica)
PATHOGEN: Xanthomonas campestris pv. mangiferaeindicae
SOURCE: APS
DISEASE: Bacterial black spot
HOST: Mango
Stem and leaf with black necroses.

Bacterial black spot | Mango
DISEASE: Bacterial black spot
HOST: Mango (Mangifera indica)
PATHOGEN: Xanthomonas campestris pv. mangiferaeindicae
SOURCE: APS
DISEASE: Bacterial black spot
HOST: Mango
Oozing cankers on young stem.

Bacterial black spot | Mango
DISEASE: Bacterial black spot
HOST: Mango (Mangifera indica)
PATHOGEN: Xanthomonas campestris pv. mangiferaeindicae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Stems with necrotic lesions.

Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Alfalfa
Leaves with brown necrotic spots. Stems have water-soaked spots.

Bacterial leaf spot | Alfalfa
DISEASE: Bacterial leaf spot
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xanthomonas alfalfae subsp. alfalfae
PATHOGEN SYNONYM: Xanthomonas campestris pv. alfalfae
SOURCE: S. Thomson