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: Bacterial leaf spot
HOST: Croton
Tan, irregular-sized lesions on lower leaf surfaces.

Bacterial leaf spot | Croton
DISEASE: Bacterial leaf spot
HOST: Croton (Codiaeum variegatum var. pictum)
PATHOGEN: Xanthomonas axonopodis pv. poinsettiicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. poinsettiicola
SOURCE: J. Yuen
DISEASE: Bacterial leaf spot
HOST: Crown-of-thorns
Leaves with brown lesions surrounded by bright yellow halos.

Bacterial leaf spot | Crown-of-thorns
DISEASE: Bacterial leaf spot
HOST: Crown-of-thorns (Euphorbia milii)
PATHOGEN: Xanthomonas axonopodis pv. poinsettiicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. poinsettiicola
SOURCE: APS
DISEASE: Bacterial leaf spot
HOST: Poinsettia
Leaves with reddish brown blighted areas and spots. Severely spotted leaves turn yellow and dehisce.

Bacterial leaf spot | Poinsettia
DISEASE: Bacterial leaf spot
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Xanthomonas axonopodis pv. poinsettiicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. poinsettiicola
SOURCE: A. Chase
DISEASE: Pith necrosis
HOST: Geranium
Geranium with wilted, yellow necrotic leaves.

Pith necrosis | Geranium
DISEASE: Pith necrosis
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Pseudomonas corrugata
SOURCE: A. Magyarosy, D. Thomas
DISEASE: Pith necrosis
HOST: Geranium
Pitted and hollow stems, one of the disease symptoms.

Pith necrosis | Geranium
DISEASE: Pith necrosis
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Pseudomonas corrugata
SOURCE: A. Magyarosy, D. Thomas
DISEASE: Pith necrosis
HOST: Geranium
Discolored stem caused by systemic infection of the pathogen.

Pith necrosis | Geranium
DISEASE: Pith necrosis
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Pseudomonas corrugata
SOURCE: A. Magyarosy, D. Thomas
DISEASE: Pith necrosis
HOST: Tomato
Cracked, dry, hollow stems with internal necrosis.

Pith necrosis | Tomato
DISEASE: Pith necrosis
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas corrugata
SOURCE: A. Alvarez
DISEASE: Pith necrosis
HOST: Tomato
External necrotic stem tissues. Initial symptoms include chlorosis of young leaves. Wilting may occur when disease is severe.

Pith necrosis | Tomato
DISEASE: Pith necrosis
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas corrugata
SOURCE: K. Natsuaki, M. Goto