DISEASE: Aster yellows
HOST: Watercress
Diseased watercress (left) and healthy plant (right).
Aster yellows | Watercress
DISEASE: Aster yellows
HOST: Watercress (Nasturtium officinale)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Aster yellows
HOST: Wheat
Healthy head (left) and diseased head (right). Diseased seedlings may die within 2 to 3 weeks. Infected heads of surviving plants are small and sterile, with distorted awns.
Aster yellows | Wheat
DISEASE: Aster yellows
HOST: Wheat (Triticum aestivum)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: L. N. Chiykowski
DISEASE: Aster yellows
HOST: Zinnia
Yellowing and shoot proliferation of foliage.
Aster yellows | Zinnia
DISEASE: Aster yellows
HOST: Zinnia (Zinnia violacea)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: J. Forsberg, M. Shurtleff
DISEASE: Carrot yellows
HOST: Carrot
Flowers with shoot proliferation (witches’-broom) (left). Healthy flower (right). Virescence and phyllody of flower parts are common.
Carrot yellows | Carrot
DISEASE: Carrot yellows
HOST: Carrot (Daucus carota)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: M. Schroth
DISEASE: Carrot yellows
HOST: Carrot
Carrot with proliferation of roots. Initial symptoms include yellowing and narrowing of veins of young leaves. The entire leaf later becomes necrotic.
Carrot yellows | Carrot
DISEASE: Carrot yellows
HOST: Carrot (Daucus carota)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: G. S. Abawi
DISEASE: Common scab (Potato scab)
HOST: Potato
Symptoms of common scab vary depending upon the cultivar. The lesions can be shallow or deep, erumpent and corky, and vary in color.
Common scab (Potato scab) | Potato
DISEASE: Common scab (Potato scab)
HOST: Potato (Solanum tuberosum)
PATHOGEN: Streptomyces scabiei
PATHOGEN SYNONYM: Streptomyces scabies
SOURCE: A. Secor
DISEASE: Common scab (Potato scab)
HOST: Potato
White-skinned tuber with sunken and superficial scab lesions.
Common scab (Potato scab) | Potato
DISEASE: Common scab (Potato scab)
HOST: Potato (Solanum tuberosum)
PATHOGEN: Streptomyces scabiei
PATHOGEN SYNONYM: Streptomyces scabies
SOURCE: S. Thomson
DISEASE: Common scab (Potato scab)
HOST: Potato
Red-skinned tuber with lesions that usually penetrate less than 1 mm.
Common scab (Potato scab) | Potato
DISEASE: Common scab (Potato scab)
HOST: Potato (Solanum tuberosum)
PATHOGEN: Streptomyces scabiei
PATHOGEN SYNONYM: Streptomyces scabies
SOURCE: S. Thomson
DISEASE: Dogwood stunt
HOST: Dogwood
Diseased plant with small leaves (left).
Dogwood stunt | Dogwood
DISEASE: Dogwood stunt
HOST: Dogwood (Cornus sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Sinclair