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: Stewart's wilt
HOST: Corn (Maize)
Wilted seedlings resulting from systemic invasion.

Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Leaf blight is the dominant symptom of this disease. Lesions begin as gray-green to yellow in color and turn brown in time.

Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Flea beetle and scars caused by feeding damage. The beetle is a vector and is an overwintering site for the bacterium.

Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Stewart's wilt
HOST: Corn (Maize)
Young wilted plant with pale green and yellow streaks on leaves.

Stewart's wilt | Corn (Maize)
DISEASE: Stewart's wilt
HOST: Corn (Maize) (Zea mays)
PATHOGEN: Pantoea stewartii subsp. stewartii
PATHOGEN SYNONYM: Erwinia stewartii
SOURCE: D. White
DISEASE: Xanthomonas leaf blight
HOST: Onion
This was the first photo of onion leaf blight, which was considered a controversial finding for 10 years until an outbreak occurred in the West Indies.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Diseased leaf with necrotic internal tissues.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez