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: Bacterial blast and fruit spot
HOST: Avocado
White bacterial ooze on surface of fruit. Pseudomonas strains that cause canker likely differ from those that infect fruit and leaves.

Bacterial blast and fruit spot | Avocado
DISEASE: Bacterial blast and fruit spot
HOST: Avocado (Persea americana)
PATHOGEN: Pseudomonas syringae
SOURCE: L. Fucikovsky
DISEASE: Bacterial canker
HOST: Avocado
Cankers on trunk.

Bacterial canker | Avocado
DISEASE: Bacterial canker
HOST: Avocado (Persea americana)
PATHOGEN: Xanthomonas campestris
SOURCE: H. Ohr
DISEASE: Fire blight
HOST: Hawthorn
Hawthorn with blossom blight.

Fire blight | Hawthorn
DISEASE: Fire blight
HOST: Hawthorn (Crataegus laevigata)
PATHOGEN: Erwinia amylovora
SOURCE: M. Shurtleff
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