DISEASE: Bacterial leaf spot of beet
HOST: Beet
Beet leaves with spots and marginal necrosis.

Bacterial leaf spot of beet | Beet
DISEASE: Bacterial leaf spot of beet
HOST: Beet (Beta vulgaris subsp. vulgaris)
PATHOGEN: Pseudomonas syringae pv. aptata
PATHOGEN SYNONYM: Pseudomonas aptata
SOURCE: P. Brown
DISEASE: Brown line and decline
HOST: Almond
Stunted and yellowish diseased tree. Such trees produce little to no growth and decline rapidly.

Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: B. Teviotdale
DISEASE: Brown line and decline
HOST: Almond
Bark was split laterally at graft union, revealing line of necrotic tissue that extends into woody cortical tissues.

Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: J. Uyemoto
DISEASE: Brown line and decline
HOST: Almond
Shriveled nuts from infected tree. Two healthy kernels (bottom left).

Brown line and decline | Almond
DISEASE: Brown line and decline
HOST: Almond (Prunus dulcis)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: J. Uyemoto
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