DISEASE: Bacterial brown rot
HOST: Orchid
Phalaenopsis orchid with yellowish brown spot on leaf (left), an early stage of disease.

Bacterial brown rot | Orchid
DISEASE: Bacterial brown rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. McMillan
DISEASE: Bacterial brown rot
HOST: Orchid
Leaves of Phalaenopsis orchid with advanced stage of decay.

Bacterial brown rot | Orchid
DISEASE: Bacterial brown rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. McMillan
DISEASE: Bacterial leaf spot
HOST: Orchid
Infected leaf of Phalaenopsis orchid with light brown necrotic area.

Bacterial leaf spot | Orchid
DISEASE: Bacterial leaf spot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Pectobacterium cypripedii
PATHOGEN SYNONYM: Erwinia cypripedii
SOURCE: R. McMillan
DISEASE: Bacterial leaf spot
HOST: Orchid
Diseased leaf of Phalaenopsis orchid with large, dark necrotic area.

Bacterial leaf spot | Orchid
DISEASE: Bacterial leaf spot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial soft rot
HOST: Orchid
Oncidium orchid with translucence and rot of central leaves.

Bacterial soft rot | Orchid
DISEASE: Bacterial soft rot
HOST: Orchid (Oncidium sp.)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: R. McMillan
DISEASE: Bacterial soft rot
HOST: Orchid
Leaf of Phalaenopsis orchid with brownish rot and discoloration running up the midrib.

Bacterial soft rot | Orchid
DISEASE: Bacterial soft rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Pectobacterium carotovorum
PATHOGEN SYNONYM: Erwinia carotovora subsp. carotovora
SOURCE: R. Raabe
DISEASE: Bacterial stem rot
HOST: Orchid
Oncidium orchid with rot at base of stem.

Bacterial stem rot | Orchid
DISEASE: Bacterial stem rot
HOST: Orchid (Oncidium sp.)
PATHOGEN: Burkholderia andropogonis
PATHOGEN SYNONYM: Pseudomonas andropogonis
SOURCE: A. Alvarez
DISEASE: Elm yellows
HOST: Elm
Elm yellows is characterized by witches'-brooms and stunting. Some cultivars have both yellow and reddish foliar discoloration.

Elm yellows | Elm
DISEASE: Elm yellows
HOST: Elm (Ulmus parvifolia)
PATHOGEN: 'Candidatus Phytoplasma ulmi'
PATHOGEN SYNONYM: Phytoplasma Elm yellows group
SOURCE: W. Sinclair