DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.
Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Angular leaf spot
HOST: Pumpkin
Leaf with lesions surrounded by light greenish halos.
Angular leaf spot | Pumpkin
DISEASE: Angular leaf spot
HOST: Pumpkin (Cucurbita pepo)
PATHOGEN: Pseudomonas syringae pv. lachrymans
SOURCE: A. Simkus, M. Shurtleff
DISEASE: Angular leaf spot
HOST: Strawberry
Early stage of disease begins as water-soaked, angular lesions, often with yellow ooze. There also are blight and vascular collapse stages.
Angular leaf spot | Strawberry
DISEASE: Angular leaf spot
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: Xanthomonas fragariae
SOURCE: M. Schroth
DISEASE: Angular leaf spot
HOST: Strawberry
Diseased sepals.
Angular leaf spot | Strawberry
DISEASE: Angular leaf spot
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: Xanthomonas fragariae
SOURCE: M. Schroth
DISEASE: Angular leaf spot
HOST: Strawberry
Vascular collapse stage occurs from systemic invasion of crown region.
Angular leaf spot | Strawberry
DISEASE: Angular leaf spot
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: Xanthomonas fragariae
SOURCE: M. Schroth
DISEASE: Aster yellows
HOST: Strawberry
Aster yellows causes flowers to be entirely phylloid. Young leaves of infected plants are small, chlorotic, and cupped and have short petioles. Red coloration may develop on older leaves.
Aster yellows | Strawberry
DISEASE: Aster yellows
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Guerrini
DISEASE: Aster yellows
HOST: Strawberry
'Marmolada' strawberry with fruit distortion and phyllody of achenes.
Aster yellows | Strawberry
DISEASE: Aster yellows
HOST: Strawberry (Fragaria × ananassa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Guerrini
DISEASE: Bacterial fruit blotch
HOST: Pumpkin
Pumpkin exhibiting early stage of disease on rind.
Bacterial fruit blotch | Pumpkin
DISEASE: Bacterial fruit blotch
HOST: Pumpkin (Cucurbita pepo)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: R. Gitaitis
DISEASE: Bacterial fruit blotch
HOST: Pumpkin
Leaves with large necrotic areas.
Bacterial fruit blotch | Pumpkin
DISEASE: Bacterial fruit blotch
HOST: Pumpkin (Cucurbita pepo)
PATHOGEN: Acidovorax citrulli
PATHOGEN SYNONYM: Acidovorax avenae subsp. citrulli
SOURCE: R. Gitaitis