DISEASE: Angular leaf spot
HOST: Tobacco
Leaf with light brown, angular spots. The difference between this disease and wildfire of tobacco is that wildfire is caused by a strain that produces tabtoxin. It causes conspicuous halos around lesions and large parts of a leaf may turn yellow .
Angular leaf spot | Tobacco
DISEASE: Angular leaf spot
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: H. Shew
DISEASE: Angular leaf spot
HOST: Tobacco
Yellowing of adjacent tissues occur as spots age (midseason). It causes conspicuous halos around lesions. Large parts of a leaf may turn yellow.
Angular leaf spot | Tobacco
DISEASE: Angular leaf spot
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: H. Shew
DISEASE: Angular leaf spot
HOST: Tobacco
Severely diseased leaf with extensive yellowing.
Angular leaf spot | Tobacco
DISEASE: Angular leaf spot
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pseudomonas syringae pv. tabaci
SOURCE: H. Shew
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: Deep bark canker
HOST: Walnut
Reddish brown exudate flowing from longitudinal cracks in the trunk. Cankers are deep extending into wood.
Deep bark canker | Walnut
DISEASE: Deep bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria rubrifaciens
PATHOGEN SYNONYM: Erwinia rubrifaciens
SOURCE: B. Teviotdale
DISEASE: Deep bark canker
HOST: Walnut
Reddish brown exudate flowing from cracks in trunk, a result of systemic invasion by the bacterium.
Deep bark canker | Walnut
DISEASE: Deep bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria rubrifaciens
PATHOGEN SYNONYM: Erwinia rubrifaciens
SOURCE: B. Teviotdale
DISEASE: Deep bark canker
HOST: Walnut
Pits in the wood and black streaks in inner bark are key diagnostic symptoms.
Deep bark canker | Walnut
DISEASE: Deep bark canker
HOST: Walnut (Juglans regia)
PATHOGEN: Brenneria rubrifaciens
PATHOGEN SYNONYM: Erwinia rubrifaciens
SOURCE: N. Schaad, M. Schroth