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
DISEASE: Bacterial blight (Angular leaf spot)
HOST: Cotton
Leaf with dark, angular leaf spots. Systemic invasion causes blackening of midribs.

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: Chocolate spot
HOST: Corn (Maize)
Leaf with dark brown, elongated spots surrounded by broad, yellow halos.

Chocolate spot | Corn (Maize)
DISEASE: Chocolate spot
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pseudomonas syringae pv. coronafaciens
SOURCE: D. White
DISEASE: Pear decline
HOST: Pear
Healthy pear shoot (left) and diseased shoots (center and right). Leaves are reddish and growth is stunted.

Pear decline | Pear
DISEASE: Pear decline
HOST: Pear (Pyrus communis)
PATHOGEN: 'Candidatus Phytoplasma pyri'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: S. Thomson
DISEASE: Pear decline
HOST: Pear
Close-up of infected pear branch showing premature reddish coloration of leaves and cupped, stunted leaves.

Pear decline | Pear
DISEASE: Pear decline
HOST: Pear (Pyrus communis)
PATHOGEN: 'Candidatus Phytoplasma pyri'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: S. Thomson
DISEASE: Pear decline
HOST: Pear
Reduced growth of infected trees in center of image.

Pear decline | Pear
DISEASE: Pear decline
HOST: Pear (Pyrus communis)
PATHOGEN: 'Candidatus Phytoplasma pyri'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: W. Sinclair
DISEASE: Pear decline
HOST: Pear
Psylla pyricola, the psyllid vector of pear decline phytoplasma.

Pear decline | Pear
DISEASE: Pear decline
HOST: Pear (Pyrus communis)
PATHOGEN: 'Candidatus Phytoplasma pyri'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: J. Clark, A. Purcell, M. Davis