DISEASE: Center rot
HOST: Onion
Early symptoms of disease are necrotic, bleached areas on young leaves that typically wilt.
Center rot | Onion
DISEASE: Center rot
HOST: Onion (Allium cepa)
PATHOGEN: Pantoea ananatis
SOURCE: R. Gitaitis
DISEASE: Center rot
HOST: Onion
Advanced stage of center rot. The bacterium has moved down from leaves into the bulb.
Center rot | Onion
DISEASE: Center rot
HOST: Onion (Allium cepa)
PATHOGEN: Pantoea ananatis
SOURCE: H. Schwartz
DISEASE: Center rot
HOST: Onion
Bulb with pale yellow, discolored decayed area.
Center rot | Onion
DISEASE: Center rot
HOST: Onion (Allium cepa)
PATHOGEN: Pantoea ananatis
SOURCE: H. Schwartz
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: X-disease (Western X) or buckskin
HOST: Cherry
Comparison of normal, dark cherries (in hand) with infected, immature cherries with less pigmentation.
X-disease (Western X) or buckskin | Cherry
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry (Prunus avium)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: A. Purcell, M. Davis