DISEASE: Bacterial wilt and dieback
HOST: Willow
Cross sections of the characteristic "watermark stain" of diseased wood. Wilt and dieback occur as disease progresses.

Bacterial wilt and dieback | Willow
DISEASE: Bacterial wilt and dieback
HOST: Willow (Salix sp.)
PATHOGEN: Brenneria salicis
PATHOGEN SYNONYM: Erwinia salicis
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Bacterial wilt and dieback
HOST: Willow
Severely diseased tree with dieback symptoms.

Bacterial wilt and dieback | Willow
DISEASE: Bacterial wilt and dieback
HOST: Willow (Salix sp.)
PATHOGEN: Brenneria salicis
PATHOGEN SYNONYM: Erwinia salicis
SOURCE: Y. Sakamoto, M. Goto
DISEASE: Oleander leaf scorch
HOST: Oleander
Diseased plant with scalloped, yellowish leaves. This usually is followed by dieback of twigs and branches. Plants often die 2 years after infection.

Oleander leaf scorch | Oleander
DISEASE: Oleander leaf scorch
HOST: Oleander (Nerium oleander)
PATHOGEN: Xylella fastidiosa
SOURCE: S. Purcell
DISEASE: Oleander leaf scorch
HOST: Oleander
Oleander with symptoms of severe scorch.

Oleander leaf scorch | Oleander
DISEASE: Oleander leaf scorch
HOST: Oleander (Nerium oleander)
PATHOGEN: Xylella fastidiosa
SOURCE: M. Blua
DISEASE: Oleander leaf scorch
HOST: Oleander
Oleander with scorch symptoms primarily at leaf tips, an early stage of disease.

Oleander leaf scorch | Oleander
DISEASE: Oleander leaf scorch
HOST: Oleander (Nerium oleander)
PATHOGEN: Xylella fastidiosa
SOURCE: M. Blua
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