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: Aster yellows
HOST: Potato
Chlorotic and stunted foliage with necrotic leaf margins. Other symptoms may be phyllody, virescence, purple or yellow pigmentation, and rolling of leaflets.
Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Aster yellows
HOST: Potato
Stunted, chlorotic plants (left) with stiff, rolled leaves.
Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Aster yellows
HOST: Potato
Diseased plant with malformed tubers.
Aster yellows | Potato
DISEASE: Aster yellows
HOST: Potato (Solanum tuberosum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Leaf with advanced stage of blight.
Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: M. Shurtleff
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Highly susceptible (left) and resistant (right) cotton cultivars. The black arm stage of the disease is the most serious and occurs when bacteria invade petioles and then stems.
Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: APS
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Characteristic early symptoms are water-soaked leaf spots and water-soaking along veins.
Bacterial blight (Angular leaf spot) | Cotton
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: A. Hayward