DISEASE: Bacterial blight (Boll rot)
HOST: Cotton
Boll rot first appears as raised, water-soaked lesions, which become sunken and turn brown to black with time.

Bacterial blight (Boll rot) | Cotton
DISEASE: Bacterial blight (Boll rot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: A. Hayward
DISEASE: Bacterial blight (Boll rot)
HOST: Cotton
Infection of bolls causes premature opening and increased susceptibility to secondary, saprophytic microorganisms that cause rot. Note discolored cotton.

Bacterial blight (Boll rot) | Cotton
DISEASE: Bacterial blight (Boll rot)
HOST: Cotton (Gossypium barbadense)
PATHOGEN: Xanthomonas citri subsp. malvacearum
PATHOGEN SYNONYM: Xanthomonas campestris pv. malvacearum
SOURCE: APS
DISEASE: Olive knot
HOST: Olive
Multiple infections of young stems. The bacterium invades vascular tissues during certain times of the year and may be isolated from branches that appear healthy.

Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth
DISEASE: Olive knot
HOST: Olive
Tree with knots/galls on branches along with twig dieback, which is associated with knots. Fusarium and Diplodia spp. infect through knots and are thought to be main reason for dieback.

Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth
DISEASE: Olive knot
HOST: Olive
Multiple infections on olive branch. Knots at this stage begin to die from the outside in and are infected by several fungi.

Olive knot | Olive
DISEASE: Olive knot
HOST: Olive (Olea europaea)
PATHOGEN: Pseudomonas savastanoi pv. savastanoi
SOURCE: M. Schroth
DISEASE: Purple stain
HOST: Papaya
Purple pigmentation of internal tissues near peduncle end of fruits. Pigmentation and yellow translucence of papaya flesh are more evident of fruit on right.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson
DISEASE: Purple stain
HOST: Papaya
Purple pigmentation of internal tissues.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: M. Nelson
DISEASE: Purple stain
HOST: Papaya
Another view of purple discoloration at peduncle end. Bacteria are found in vascular tissues and latex ducts.

Purple stain | Papaya
DISEASE: Purple stain
HOST: Papaya (Carica papaya)
PATHOGEN: Pantoea agglomerans
PATHOGEN SYNONYM: Erwinia herbicola
SOURCE: K. Nishijima