DISEASE: Bacterial blast and fruit spot
HOST: Avocado
White bacterial ooze on surface of fruit. Pseudomonas strains that cause canker likely differ from those that infect fruit and leaves.

Bacterial blast and fruit spot | Avocado
DISEASE: Bacterial blast and fruit spot
HOST: Avocado (Persea americana)
PATHOGEN: Pseudomonas syringae
SOURCE: L. Fucikovsky
DISEASE: Bacterial leaf scorch
HOST: Pecan
Pecan with necrotic scorched leaves with distinct dark lines between healthy and diseased tissues.

Bacterial leaf scorch | Pecan
DISEASE: Bacterial leaf scorch
HOST: Pecan (Carya illinoinensis)
PATHOGEN: Xylella fastidiosa
SOURCE: T. Brenneman
DISEASE: Bacterial leaf scorch
HOST: Sycamore
Sycamore with scorched leaves and dieback of small branches.

Bacterial leaf scorch | Sycamore
DISEASE: Bacterial leaf scorch
HOST: Sycamore (Platanus occidentalis)
PATHOGEN: Xylella fastidiosa
SOURCE: W. Sinclair
DISEASE: Bacterial leaf scorch
HOST: Sycamore
Close-up of scorched leaves.

Bacterial leaf scorch | Sycamore
DISEASE: Bacterial leaf scorch
HOST: Sycamore (Platanus occidentalis)
PATHOGEN: Xylella fastidiosa
SOURCE: W. Sinclair
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
DISEASE: Xanthomonas leaf blight
HOST: Onion
Onions with severely 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