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: Bacterial leaf spot
HOST: Collard
Leaf with several kinds of spots. Small necrotic lesions with yellow halos, brown lesions, and large, brown necrotic areas caused by coalescing of lesions.

Bacterial leaf spot | Collard
DISEASE: Bacterial leaf spot
HOST: Collard (Brassica oleracea var. acephala)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: S. Miller
DISEASE: Bacterial rot
HOST: Dracaena
Rot at base of leaves.

Bacterial rot | Dracaena
DISEASE: Bacterial rot
HOST: Dracaena (Dracaena deremensis)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: A. Alvarez