DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Bunch disease
HOST: Walnut
Foliage with bunchlike symptoms.

Bunch disease | Walnut
DISEASE: Bunch disease
HOST: Walnut (Juglans nigra)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: R. Green
DISEASE: Halo blight
HOST: Bean
'Baby Fordhook' with water-soaked leaf lesions without halos. This strain of the pathogen is not systemic on this cultivar.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus lunatus 'Baby Fordhook')
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: M. Schroth