DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Dark, rotted areas of stalk and leaves caused by systemic invasion of the pathogen.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: S. Mohan
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Gray-brown rot of onion after inoculation. Disease starts as small, water-soaked lesions that later develop into slimy, gray-brown rot. The disease progresses downward from the stalk and may rot the entire bulb.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: R. Gitaitis
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Leaves with necrosis and rot. The common name for this disease is the same as those used for two other diseases. Also, another common name for this disease is bacterial soft rot.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: S. Mohan
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: 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
DISEASE: Witches'-broom
HOST: Citrus (Lime)
Lime tree with compact, small leaves (witches'-broom). Leaves on older brooms dry out and eventually drop, leaving dead, bare branches. There are no flowers or fruit on brooms.

Witches'-broom | Citrus (Lime)
DISEASE: Witches'-broom
HOST: Citrus (Lime) (Citrus sp.)
PATHOGEN: 'Candidatus Phytoplasma aurantifolia'
PATHOGEN SYNONYM: Phytoplasma Peanut witches'-broom group
SOURCE: J. Bove, M. Garnier