DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.

Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
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
DISEASE: Xanthomonas leaf blight
HOST: Onion
Severely blighted onion 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 wilt
HOST: Banana
Cross sections exposing discoloration of infected fruit.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen
DISEASE: Xanthomonas wilt
HOST: Banana
Sliced diseased stem exposing discolored vascular tissues and bacterial ooze.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen
DISEASE: Xanthomonas wilt
HOST: Banana
Longitudinal sections of fruit exposing brownish red diseased tissues.

Xanthomonas wilt | Banana
DISEASE: Xanthomonas wilt
HOST: Banana (Musa × paradisiaca 'Pisang Awak')
PATHOGEN: Xanthomonas campestris pv. musacearum
PATHOGEN SYNONYM: Xanthomonas campestris
SOURCE: I. Buddenhagen