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
Advanced stage of disease with dry, brownish necrotic lesions on upper leaf surface.
Angular leaf spot | Strawberry
DISEASE: Angular leaf spot
HOST: Strawberry (Fragaria chiloensis)
PATHOGEN: Xanthomonas fragariae
SOURCE: A. Alvarez
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: Onion
Infected plants with yellowish, malformed leaves.
Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Rowe
DISEASE: Aster yellows
HOST: Onion
Onion flower with unusual symptoms (left) compared with healthy inflorescence (right). Flowers are distorted and often have abnormally long pedicels. Young leaves may have yellow streaks or a general yellowing of basal portions.
Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
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 flower stalk and leaf necrosis
HOST: Onion
Dark, rotted areas of stalk and leaves caused by systemic invasion of the pathogen.
Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: S. Mohan