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: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.
Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.
Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Bacterial canker
HOST: Almond
Infected tissues with reddish necrotic spots, a key diagnostic symptom for the disease. Spots and streaks are commonly seen when bark is removed.
Bacterial canker | Almond
DISEASE: Bacterial canker
HOST: Almond (Prunus dulcis)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: B. Teviotdale
DISEASE: Bacterial canker
HOST: Almond
Diamond-shaped canker on infected limb. Such cankers are common on small limbs and spurs.
Bacterial canker | Almond
DISEASE: Bacterial canker
HOST: Almond (Prunus dulcis)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: B. Teviotdale
DISEASE: Bacterial canker
HOST: Avocado
Cankers on trunk.
Bacterial canker | Avocado
DISEASE: Bacterial canker
HOST: Avocado (Persea americana)
PATHOGEN: Xanthomonas campestris
SOURCE: H. Ohr
DISEASE: Bacterial canker
HOST: Cherry
Cherry with necrotic internal tissues and external symptoms of ooze (gummosis) caused by systemic infection.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. morsprunorum
SOURCE: D. Funk, A. Alvarez
DISEASE: Bacterial canker
HOST: Cherry
Systemic infection of petioles and leaves.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. morsprunorum
SOURCE: D. Funk, A. Alvarez
DISEASE: Bacterial canker
HOST: Cherry
Blast stage of canker disease affects flowers, buds, and leaves. Necrotic lesions on fruit may cause distortion.
Bacterial canker | Cherry
DISEASE: Bacterial canker
HOST: Cherry (Prunus avium)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: S. Thomson