DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.
Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Greening disease
HOST: Periwinkle
Healthy flower and infected flower.
Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: D. Teakle
DISEASE: Greening disease
HOST: Periwinkle
Diseased plants with phyllody and greenish yellow leaves.
Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Vinca minor)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Braun
DISEASE: Greening disease
HOST: Periwinkle
The disease causes virescence and phyllody, distorted and discolored leaves, and greening of flowers.
Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Catharanthus roseus)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Shallow bark canker
HOST: Walnut
Diseased, discolored tissues revealed by removing external bark.
Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: Shallow bark canker
HOST: Walnut
Trunk with brown exudate shallow cankers.
Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale
DISEASE: Shallow bark canker
HOST: Walnut
Multiple cankers with brown exudate. Cankers on trunk are shallow.
Shallow bark canker | Walnut
DISEASE: Shallow bark canker
HOST: Walnut (Juglans regia 'Hartley')
PATHOGEN: Brenneria nigrifluens
PATHOGEN SYNONYM: Erwinia nigrifluens
SOURCE: B. Teviotdale