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: Hollow stalk
HOST: Tobacco
Hollow stalk may appear at time of topping and suckering. Top leaves wilt and the stalk becomes bare as the disease moves downward.
Hollow stalk | Tobacco
DISEASE: Hollow stalk
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: P. Shoemaker
DISEASE: Hollow stalk
HOST: Tobacco
Infection of flue-cured tobacco stalks occur at wound sites caused by topping. After top infection, browning of pith occurs and tissues rot.
Hollow stalk | Tobacco
DISEASE: Hollow stalk
HOST: Tobacco (Nicotiana tabacum)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: APS