DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).

Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Blister spot
HOST: Apple
Late stage of blister spot. The purplish black lesions are associated with lenticels and stomata.

Blister spot | Apple
DISEASE: Blister spot
HOST: Apple (Malus domestica 'Crispin')
PATHOGEN: Pseudomonas syringae pv. papulans
SOURCE: T. Burr
DISEASE: Bois noir disease
HOST: Grape
Infected plant with typical symptoms of rolling, triangular-trapezoid-shaped leaves with desiccated appearance.

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