DISEASE: Bacterial canker
HOST: Hazelnut
Primary symptoms are failure of buds to break and withering and death of new foliage in spring. Dead leaves remain attached to limbs after normal leaf fall.
Bacterial canker | Hazelnut
DISEASE: Bacterial canker
HOST: Hazelnut (Corylus americana)
PATHOGEN: Pseudomonas syringae pv. avellanae
PATHOGEN SYNONYM: Pseudomonas avellanae
SOURCE: P. Psalidas
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Dieffenbachia with rot and decay of stem and leaf tissues.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: A. Alvarez
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Dieffenbachia with wilted and rotted leaves.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: R. Raabe
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Cross section of stem exposing rotted tissues.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: R. Raabe
DISEASE: Bacterial stem rot
HOST: Dieffenbachia
Leaf with rot and wilt.
Bacterial stem rot | Dieffenbachia
DISEASE: Bacterial stem rot
HOST: Dieffenbachia (Dieffenbachia seguine)
PATHOGEN: Dickeya dieffenbachiae
PATHOGEN SYNONYM: Erwinia chrysanthemi pv. dieffenbachiae
SOURCE: R. Raabe
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