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: Cowpea
Leaf spots vary in size from small to large and some fall out in time, leaving a shot-hole appearance.
Bacterial leaf spot | Cowpea
DISEASE: Bacterial leaf spot
HOST: Cowpea (Vigna unguiculata)
PATHOGEN: Xanthomonas axonopodis pv. vignicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. vignicola
SOURCE: R. Gitaitis
DISEASE: Bacterial leaf spot
HOST: Cowpea
Leaves with large, light brown necrotic areas.
Bacterial leaf spot | Cowpea
DISEASE: Bacterial leaf spot
HOST: Cowpea (Vigna unguiculata)
PATHOGEN: Xanthomonas axonopodis pv. vignicola
PATHOGEN SYNONYM: Xanthomonas campestris pv. vignicola
SOURCE: R. Gitaitis
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