DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Leaves with tiny lesions surrounded by large halos.

Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Section of a cauliflower head with discolored, infected tissues.

Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
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 leaf spot
HOST: Radish
Leaf with brown lesions, some with a water-soaked appearance.

Bacterial leaf spot | Radish
DISEASE: Bacterial leaf spot
HOST: Radish (Raphanus sativus var. longipinnatus)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: J. Togashi, M. Goto
DISEASE: Bacterial stripe (Blight)
HOST: Oat
Leaves with irregular necrotic spots and elongated stripes that are light tan in the center. Symptoms begin as water-soaked lesions.

Bacterial stripe (Blight) | Oat
DISEASE: Bacterial stripe (Blight)
HOST: Oat (Avena sativa)
PATHOGEN: Pseudomonas syringae pv. striafaciens
SOURCE: S. Thomson
DISEASE: Xanthomonas leaf blight
HOST: Onion
This was the first photo of onion leaf blight, which was considered a controversial finding for 10 years until an outbreak occurred in the West Indies.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Diseased leaf with necrotic internal tissues.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Onions with brown, necrotic, blighted leaves.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: H. Schwartz