DISEASE: Aster yellows
HOST: Aster
Foliar symptoms of chlorosis, malformation of leaves, and phyllody.
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Flowers with phyllody (left and center). Healthy flower (right).
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. McCoy, M. Davis
DISEASE: Aster yellows
HOST: Aster
Macrosteles sp., a leafhopper vector of aster yellows phytoplasma.
Aster yellows | Aster
DISEASE: Aster yellows
HOST: Aster (Aster sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Clark, A. Purcell, M. Davis
DISEASE: Bacterial leaf spot
HOST: Peanut
The disease causes water-soaked lesions, particularly on upper leaf surfaces. Lesions enlarge and later display brown necrotic areas. Leaflets become chlorotic and shed prematurely.
Bacterial leaf spot | Peanut
DISEASE: Bacterial leaf spot
HOST: Peanut (Arachis hypogaea)
PATHOGEN: Pseudomonas sp.
SOURCE: P. Subrahmanyam
DISEASE: Bacterial stem and root rot
HOST: Sweet potato
Collapse of stems and roots caused by systemic activity of the pathogen.
Bacterial stem and root rot | Sweet potato
DISEASE: Bacterial stem and root rot
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: N. Schaad
DISEASE: Bacterial stem and root rot
HOST: Sweet potato
Rot and collapse of stem, petioles, and leaves caused by systemic infection.
Bacterial stem and root rot | Sweet potato
DISEASE: Bacterial stem and root rot
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: N. Schaad
DISEASE: Bacterial stem and root rot
HOST: Sweet potato
Rot and internal discoloration of tuber.
Bacterial stem and root rot | Sweet potato
DISEASE: Bacterial stem and root rot
HOST: Sweet potato (Ipomoea batatas)
PATHOGEN: Dickeya sp.
PATHOGEN SYNONYM: Erwinia chrysanthemi
SOURCE: C. Clark
DISEASE: Bacterial wilt
HOST: Peanut
First sign of disease is slight drooping or curling of leaves. As the plant declines, foliage turns yellow, followed by wilt and death of stems.
Bacterial wilt | Peanut
DISEASE: Bacterial wilt
HOST: Peanut (Arachis hypogaea)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: D. Porter
DISEASE: Bacterial wilt
HOST: Peanut
Advanced stage of disease with death of plants.
Bacterial wilt | Peanut
DISEASE: Bacterial wilt
HOST: Peanut (Arachis hypogaea)
PATHOGEN: Ralstonia solanacearum
PATHOGEN SYNONYM: Pseudomonas solanacearum
SOURCE: D. Porter