DISEASE: Aster yellows
HOST: Aster
Foliar symptoms of chlorosis, malformation of leaves, and phyllody.

Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Flowers with phyllody (left and center). Healthy flower (right).

Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Macrosteles sp., a leafhopper vector of aster yellows phytoplasma.

Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Clark, A. Purcell, M. Davis
DISEASE: Bacterial stalk and top rot
HOST: Corn (Maize)
Corn exhibiting symptoms at early stage of disease. Note water-soaked external stalk tissues.

Bacterial stalk and top rot | Corn (Maize)
DISEASE: Bacterial stalk and top rot
HOST: Corn (Maize) (Zea mays 'Pukekohe')
PATHOGEN: Dickeya zeae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. zeae
SOURCE: J. Young
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