RESULTS

(11)

FILTER

DISEASE: Bacterial blight

HOST: Hazelnut

Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.

Bacterial blight | Hazelnut

DISEASE: Bacterial blight

HOST: Hazelnut (Corylus americana)

PATHOGEN: Xanthomonas arboricola pv. corylina

SOURCE: J. Pscheidt

DISEASE: Elm yellows

HOST: Elm

Symptoms of elm yellows occasionally appear on one branch before others, but more often they involve the entire crown.

Elm yellows | Elm

DISEASE: Elm yellows

HOST: Elm (Ulmus americana)

PATHOGEN: 'Candidatus Phytoplasma ulmi'

PATHOGEN SYNONYM: Phytoplasma Elm yellows group

SOURCE: W. Sinclair

DISEASE: Elm yellows

HOST: Elm

Diseased twig (right) with epinasty, chlorosis, and yellowing of leaves. Sometimes both yellow and green leaves occur on same branch. Healthy branch (left).

Elm yellows | Elm

DISEASE: Elm yellows

HOST: Elm (Ulmus americana)

PATHOGEN: 'Candidatus Phytoplasma ulmi'

PATHOGEN SYNONYM: Phytoplasma Elm yellows group

SOURCE: W. Sinclair

DISEASE: Elm yellows

HOST: Elm

Branches with butterscotch discoloration (center) and necrotic flecks in phloem and vascular cambium (right). Healthy branch (left). Sudden wilt and browning is common with small trees.

Elm yellows | Elm

DISEASE: Elm yellows

HOST: Elm (Ulmus americana)

PATHOGEN: 'Candidatus Phytoplasma ulmi'

PATHOGEN SYNONYM: Phytoplasma Elm yellows group

SOURCE: W. Sinclair

DISEASE: Elm yellows

HOST: Elm

Elm yellows is characterized by witches'-brooms and stunting. Some cultivars have both yellow and reddish foliar discoloration.

Elm yellows | Elm

DISEASE: Elm yellows

HOST: Elm (Ulmus parvifolia)

PATHOGEN: 'Candidatus Phytoplasma ulmi'

PATHOGEN SYNONYM: Phytoplasma Elm yellows group

SOURCE: W. Sinclair

DISEASE: Elm yellows

HOST: Elm

Late stage of elm yellows disease.

Elm yellows | Elm

DISEASE: Elm yellows

HOST: Elm (Ulmus rubra)

PATHOGEN: 'Candidatus Phytoplasma ulmi'

PATHOGEN SYNONYM: Phytoplasma Elm yellows group

SOURCE: W. Sinclair

DISEASE: Pith necrosis

HOST: Geranium

Geranium with wilted, yellow necrotic leaves.

Pith necrosis | Geranium

DISEASE: Pith necrosis

HOST: Geranium (Pelargonium sp.)

PATHOGEN: Pseudomonas corrugata

SOURCE: A. Magyarosy, D. Thomas

DISEASE: Pith necrosis

HOST: Geranium

Pitted and hollow stems, one of the disease symptoms.

Pith necrosis | Geranium

DISEASE: Pith necrosis

HOST: Geranium (Pelargonium sp.)

PATHOGEN: Pseudomonas corrugata

SOURCE: A. Magyarosy, D. Thomas

DISEASE: Pith necrosis

HOST: Geranium

Discolored stem caused by systemic infection of the pathogen.

Pith necrosis | Geranium

DISEASE: Pith necrosis

HOST: Geranium (Pelargonium sp.)

PATHOGEN: Pseudomonas corrugata

SOURCE: A. Magyarosy, D. Thomas