DISEASE: Bacterial brown rot
HOST: Orchid
Phalaenopsis orchid with yellowish brown spot on leaf (left), an early stage of disease.
Bacterial brown rot | Orchid
DISEASE: Bacterial brown rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. McMillan
DISEASE: Bacterial brown rot
HOST: Orchid
Leaves of Phalaenopsis orchid with advanced stage of decay.
Bacterial brown rot | Orchid
DISEASE: Bacterial brown rot
HOST: Orchid (Phalaenopsis sp.)
PATHOGEN: Acidovorax cattleyae
PATHOGEN SYNONYM: Acidovorax avenae subsp. cattleyae
SOURCE: R. McMillan
DISEASE: Tomato big bud
HOST: Tomato
Characteristic symptoms are swollen, apical stems and stunted leaves. Apical stems are generally thickened and assume a stiff and erect growth habit. Internodes are shortened and flower buds are greatly enlarged.
Tomato big bud | Tomato
DISEASE: Tomato big bud
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: D. Teakle
DISEASE: Tomato big bud
HOST: Tomato
Symptoms are enlarge sepals that do not separate. Flower buds stay green and do not develop into fruit. Leaves are small and chlorotic.
Tomato big bud | Tomato
DISEASE: Tomato big bud
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Tomato big bud
HOST: Tomato
Abnormal flower bud with greatly enlarged sepals. Sepals do not separate, fruit is not produced, and apical growth is upright.
Tomato big bud | Tomato
DISEASE: Tomato big bud
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Thomson
DISEASE: Tomato big bud
HOST: Tomato
Sliced stems with phloem necrosis and brown discoloration.
Tomato big bud | Tomato
DISEASE: Tomato big bud
HOST: Tomato (Lycopersicon esculentum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: D. Teakle
DISEASE: Witches'-broom
HOST: Alfalfa
Alfalfa plant (center) exhibiting stunting and proliferation of stems. Other symptoms are small, rounded, chlorotic, often puckered leaves and a yellowish cast.
Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Young plant (left) with small, numerous stems (witches'-broom). Healthy stems (right).
Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Cactus
Witches'-broom of Opuntia cactus.
Witches'-broom | Cactus
DISEASE: Witches'-broom
HOST: Cactus (Opuntia sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis