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: Pierce's disease
HOST: Grape
Leaves with bright yellow, chlorotic areas with dead, dry, necrotic adjacent tissues.

Pierce's disease | Grape
DISEASE: Pierce's disease
HOST: Grape (Vitis vinifera)
PATHOGEN: Xylella fastidiosa
SOURCE: J. Clark, S. Purcell
DISEASE: Pierce's disease
HOST: Grape
Early symptoms of Pierce's disease on leaves. Symptoms vary greatly among cultivars.

Pierce's disease | Grape
DISEASE: Pierce's disease
HOST: Grape (Vitis vinifera 'Chardonnay')
PATHOGEN: Xylella fastidiosa
SOURCE: J. Clark, S. Purcell
DISEASE: Pierce's disease
HOST: Grape
Late-season wood on diseased canes fail to mature, leaving green "islands" of tissue surrounded by dark brown, mature wood.

Pierce's disease | Grape
DISEASE: Pierce's disease
HOST: Grape (Vitis vinifera 'Fiesta')
PATHOGEN: Xylella fastidiosa
SOURCE: S. Purcell
DISEASE: Syringae leaf spot
HOST: Tomato
Leaves with brown necrotic lesions and chlorotic margins. Symptoms vary greatly among cultivars. Some have black or brown lesions with bright yellow, chlorotic areas and others do not have yellowing.

Syringae leaf spot | Tomato
DISEASE: Syringae leaf spot
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: R. Gitaitis