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: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.
Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial blight
HOST: Geranium
Leaf with many necrotic spots and chlorotic V-shaped lesions.
Bacterial blight | Geranium
DISEASE: Bacterial blight
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Xanthomonas hortorum pv. pelargonii
PATHOGEN SYNONYM: Xanthomonas campestris pv. pelargonii
SOURCE: M. Daughtrey
DISEASE: Bacterial blight
HOST: Geranium
Blight symptoms are affected by environmental conditions and cultivar type. Here, large, sunken, brown, circular lesions have a brownish discoloration around some lesions.
Bacterial blight | Geranium
DISEASE: Bacterial blight
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Xanthomonas hortorum pv. pelargonii
PATHOGEN SYNONYM: Xanthomonas campestris pv. pelargonii
SOURCE: M. Daughtrey
DISEASE: Bacterial blight
HOST: Geranium
Geranium with wilted and necrotic leaves.
Bacterial blight | Geranium
DISEASE: Bacterial blight
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Xanthomonas hortorum pv. pelargonii
PATHOGEN SYNONYM: Xanthomonas campestris pv. pelargonii
SOURCE: R. Raabe
DISEASE: Bacterial blight
HOST: Geranium
Left and center leaves have spots, whereas leaf on right also has blight symptoms.
Bacterial blight | Geranium
DISEASE: Bacterial blight
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Xanthomonas hortorum pv. pelargonii
PATHOGEN SYNONYM: Xanthomonas campestris pv. pelargonii
SOURCE: M. Shurtleff
DISEASE: Bacterial blight
HOST: Geranium
Severely blighted leaves, stems, and petioles.
Bacterial blight | Geranium
DISEASE: Bacterial blight
HOST: Geranium (Pelargonium sp.)
PATHOGEN: Xanthomonas hortorum pv. pelargonii
PATHOGEN SYNONYM: Xanthomonas campestris pv. pelargonii
SOURCE: S. Thomson