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: Larkspur virescence
HOST: Larkspur
Two diseased plants with stunted and small leaves, lack of flower coloration, and bunched flower buds. Healthy plant (left).

Larkspur virescence | Larkspur
DISEASE: Larkspur virescence
HOST: Larkspur (Delphinium sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
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