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: Coffee leaf scorch
HOST: Coffee
Diseased twig with yellowish, stunted leaves (left). Healthy twig with normal-sized leaves (right).

Coffee leaf scorch | Coffee
DISEASE: Coffee leaf scorch
HOST: Coffee (Coffea arabica)
PATHOGEN: Xylella fastidiosa
SOURCE: S. Purcell
DISEASE: Halo blight
HOST: Bean
Chlorotic, systemic symptoms with necrotic lesions on leaves of 'Romano' common bean.

Halo blight | Bean
DISEASE: Halo blight
HOST: Bean (Phaseolus vulgaris 'Romano')
PATHOGEN: Pseudomonas syringae pv. phaseolicola
PATHOGEN SYNONYM: Pseudomonas savastanoi pv. phaseolicola
SOURCE: M. Schroth
DISEASE: Halo blight
HOST: Bean
Chlorotic, systemic symptoms with no visible lesions on leaves of 'Romano' common bean.

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