DISEASE: Bacterial leaf and stem necrosis
HOST: Watermelon
Seedlings with necrotic leaves and water-soaked stems.
Bacterial leaf and stem necrosis | Watermelon
DISEASE: Bacterial leaf and stem necrosis
HOST: Watermelon (Citrullus lanatus)
PATHOGEN: Pseudomonas viridiflava
SOURCE: Y. Aysan
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum
Leaves with irregular necrotic lesions.
Bacterial leaf spot and canker | Sweetgum
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum (Liquidambar styraciflua)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: A. Bishop
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum
Stem canker of sweetgum.
Bacterial leaf spot and canker | Sweetgum
DISEASE: Bacterial leaf spot and canker
HOST: Sweetgum (Liquidambar styraciflua)
PATHOGEN: Pseudomonas syringae pv. syringae
SOURCE: A. Bishop
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