DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).
Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lemon)
The term "black pit" refers to black lesions on fruit, which may be specks or large, sunken pits as seen here. They also may be light tan, later becoming reddish brown to black.
Bacterial blast and black pit | Citrus (Lemon)
DISEASE: Bacterial blast and black pit
HOST: Citrus (Lemon) (Citrus limon)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: J. Menge
DISEASE: Bacterial leaf spot
HOST: Ivy
Algerian ivy with mostly black spots without halos.
Bacterial leaf spot | Ivy
DISEASE: Bacterial leaf spot
HOST: Ivy (Hedera canariensis)
PATHOGEN: Xanthomonas hortorum pv. hederae
PATHOGEN SYNONYM: Xanthomonas campestris pv. hederae
SOURCE: M. Schroth
DISEASE: Citrus canker
HOST: Citrus (Lemon)
Lower leaf with raised, corkylike lesions surrounded by dark brown halos, one of the diagnostic symptoms of citrus canker.
Citrus canker | Citrus (Lemon)
DISEASE: Citrus canker
HOST: Citrus (Lemon) (Citrus limon)
PATHOGEN: Xanthomonas citri subsp. citri
PATHOGEN SYNONYM: Xanthomonas citri
SOURCE: T. Gottwald