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: Halo blight
HOST: Rice
Leaves with yellowish brown lesions, 2 to 10 mm in diameter. Lesions are surrounded by distinct halos. Later, brown spots or stripes may develop in the center.

Halo blight | Rice
DISEASE: Halo blight
HOST: Rice (Oryza sativa)
PATHOGEN: Pseudomonas syringae pv. oryzae
SOURCE: H. Kuwata
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