DISEASE: Bacterial leaf spot
HOST: Snapdragon
Leaves with large necrotic areas with brownish centers and purplish margins. Lesions are slightly sunken.
Bacterial leaf spot | Snapdragon
DISEASE: Bacterial leaf spot
HOST: Snapdragon (Antirrhinum majus)
PATHOGEN: Pseudomonas syringae pv. antirrhini
SOURCE: R. Raabe
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: Pear decline
HOST: Pear
'Bartlett' pears were grafted onto tolerant rootstock. All trees are infected. Note yellowish, diseased branches.
Pear decline | Pear
DISEASE: Pear decline
HOST: Pear (Pyrus communis 'Bartlett')
PATHOGEN: 'Candidatus Phytoplasma pyri'
PATHOGEN SYNONYM: Phytoplasma Apple proliferation group
SOURCE: C. Smart