DISEASE: Center rot
HOST: Onion
Early symptoms of disease are necrotic, bleached areas on young leaves that typically wilt.
Center rot | Onion
DISEASE: Center rot
HOST: Onion (Allium cepa)
PATHOGEN: Pantoea ananatis
SOURCE: R. Gitaitis
DISEASE: Center rot
HOST: Onion
Advanced stage of center rot. The bacterium has moved down from leaves into the bulb.
Center rot | Onion
DISEASE: Center rot
HOST: Onion (Allium cepa)
PATHOGEN: Pantoea ananatis
SOURCE: H. Schwartz
DISEASE: Center rot
HOST: Onion
Bulb with pale yellow, discolored decayed area.
Center rot | Onion
DISEASE: Center rot
HOST: Onion (Allium cepa)
PATHOGEN: Pantoea ananatis
SOURCE: H. Schwartz
DISEASE: Shallow bark canker
HOST: Walnut
Diseased, discolored tissues revealed by removing external bark.
Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: Shallow bark canker
HOST: Walnut
Trunk with brown exudate shallow cankers.
Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: Shallow bark canker
HOST: Walnut
Multiple cankers with brown exudate. Cankers on trunk are shallow.
Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: X-disease
HOST: Peach
Typical symptoms of diseased tree with yellowing of leaves. Leaves become necrotic and dehisce.
X-disease | Peach
DISEASE: X-disease
HOST: Peach (Prunus persica)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: R. Davis, M. Davis
DISEASE: X-disease
HOST: Peach
Late stage of leaf infection. Red-yellow blotches appear after initial water-soaking of leaves. Margins roll upward and leaves appear tattered.
X-disease | Peach
DISEASE: X-disease
HOST: Peach (Prunus persica)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: W. Sinclair
DISEASE: X-disease
HOST: Peach
Stunted foliage (left) with some necrosis and small angular fruit. Healthy foliage and fruit (right).
X-disease | Peach
DISEASE: X-disease
HOST: Peach (Prunus persica)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: A. Purcell, M. Davis