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: Sheath brown rot
HOST: Rice
Disease symptoms typically occur on flag leaf sheaths from booting to heading stage and also on panicles. Water-soaked lesions on glumes turn light brown.
Sheath brown rot | Rice
DISEASE: Sheath brown rot
HOST: Rice (Oryza sativa)
PATHOGEN: Burkholderia fuscovaginae
PATHOGEN SYNONYM: Pseudomonas fuscovaginae
SOURCE: K. Miyajima, M. Goto
DISEASE: Sheath brown rot
HOST: Rice
Close-up of stem lesions.
Sheath brown rot | Rice
DISEASE: Sheath brown rot
HOST: Rice (Oryza sativa)
PATHOGEN: Burkholderia fuscovaginae
PATHOGEN SYNONYM: Pseudomonas fuscovaginae
SOURCE: K. Miyajima, M. Goto
DISEASE: Sheath brown rot
HOST: Rice
Seedling with rot symptoms.
Sheath brown rot | Rice
DISEASE: Sheath brown rot
HOST: Rice (Oryza sativa)
PATHOGEN: Burkholderia fuscovaginae
PATHOGEN SYNONYM: Pseudomonas fuscovaginae
SOURCE: K. Miyajima, M. Goto