DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape
Stem necrosis of grape.

Bacterial blight (Bacterial necrosis) | Grape
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape (Vitis vinifera)
PATHOGEN: Xylophilus ampelinus
PATHOGEN SYNONYM: Xanthomonas ampelina
SOURCE: N. Schaad
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape
Stem with cankers and discolored external tissues.

Bacterial blight (Bacterial necrosis) | Grape
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape (Vitis vinifera)
PATHOGEN: Xylophilus ampelinus
PATHOGEN SYNONYM: Xanthomonas ampelina
SOURCE: N. Schaad
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape
Severe infection in vineyard is noted by dead canes. Symptoms are most severe in spring; shoot blight, occasional spots on leaves, and cankers are common.

Bacterial blight (Bacterial necrosis) | Grape
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape (Vitis vinifera)
PATHOGEN: Xylophilus ampelinus
PATHOGEN SYNONYM: Xanthomonas ampelina
SOURCE: C. Manceau, N. Schaad
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape
Leaf with necrotic spots and marginal necrosis. One-sided cracking of petiole tissue is common (not shown here).

Bacterial blight (Bacterial necrosis) | Grape
DISEASE: Bacterial blight (Bacterial necrosis)
HOST: Grape (Vitis vinifera)
PATHOGEN: Xylophilus ampelinus
PATHOGEN SYNONYM: Xanthomonas ampelina
SOURCE: C. Panagopoulos
DISEASE: Bacterial bud and petal blight
HOST: Orchid
Miltonia orchid with brownish necrotic areas around edges of flower petals.

Bacterial bud and petal blight | Orchid
DISEASE: Bacterial bud and petal blight
HOST: Orchid (Miltonia sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial bud and petal blight
HOST: Orchid
Miltonia orchid with diseased water-soaked flower buds.

Bacterial bud and petal blight | Orchid
DISEASE: Bacterial bud and petal blight
HOST: Orchid (Miltonia sp.)
PATHOGEN: Acidovorax cattleyae
SOURCE: R. Raabe
DISEASE: Bacterial leaf blight and rot
HOST: Orchid
Orchid hybrid (Miltonia × Bert Field 'Eileen') with water-soaked, discolored area near base of leaf.

Bacterial leaf blight and rot | Orchid
DISEASE: Bacterial leaf blight and rot
HOST: Orchid (Miltonia sp.)
PATHOGEN: Burkholderia gladioli pv. gladioli
PATHOGEN SYNONYM: Pseudomonas gladioli pv. gladioli
SOURCE: L. Keith
DISEASE: Bois noir disease
HOST: Grape
Severe symptoms of triangular-trapezoid-shaped leaves with desiccated appearance.

Bois noir disease | Grape
DISEASE: Bois noir disease
HOST: Grape (Vitis vinifera)
PATHOGEN: 'Candidatus Phytoplasma solani'
PATHOGEN SYNONYM: Phytoplasma Stolbur group
SOURCE: W. Schweigkofler