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
DISEASE: Oleander knot
HOST: Oleander
Oleander with small knots/galls on leaf and stems.
Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: W. Sinclair
DISEASE: Oleander knot
HOST: Oleander
Young stem with knots/galls.
Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: R. Raabe
DISEASE: Oleander knot
HOST: Oleander
Leaf with early stage of knot/gall formation.
Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: R. Raabe
DISEASE: Oleander knot
HOST: Oleander
Infected flowers with small knots/galls and necroses.
Oleander knot | Oleander
DISEASE: Oleander knot
HOST: Oleander (Nerium oleander)
PATHOGEN: Pseudomonas savastanoi pv. nerii
SOURCE: W. Sinclair
DISEASE: Witches'-broom
HOST: Alfalfa
Alfalfa plant (center) exhibiting stunting and proliferation of stems. Other symptoms are small, rounded, chlorotic, often puckered leaves and a yellowish cast.
Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Young plant (left) with small, numerous stems (witches'-broom). Healthy stems (right).
Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Cactus
Witches'-broom of Opuntia cactus.
Witches'-broom | Cactus
DISEASE: Witches'-broom
HOST: Cactus (Opuntia sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis