DISEASE: Almond leaf scorch
HOST: Almond
Light brown necrotic (scorched) areas on curling leaves.

Almond leaf scorch | Almond
DISEASE: Almond leaf scorch
HOST: Almond (Prunus dulcis)
PATHOGEN: Xylella fastidiosa
SOURCE: W. Sinclair
DISEASE: Almond leaf scorch
HOST: Almond
Dying almond trees with scorched appearance. Initial symptoms are marginal chlorosis, usually late in the year. Scorch often is first noted at leaf tips, symptoms worsen, and terminal branches may die.

Almond leaf scorch | Almond
DISEASE: Almond leaf scorch
HOST: Almond (Prunus dulcis)
PATHOGEN: Xylella fastidiosa
SOURCE: R. Davis, M. Davis
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 blight
HOST: Bean
Bean leaves with large necrotic areas.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: J. Young
DISEASE: Bacterial blight
HOST: Bean
Field of severely diseased beans.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: M. Shurtleff
DISEASE: Bacterial blight
HOST: Bean
Close-up of necrotic leaf lesions.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: A. Alvarez
DISEASE: Bacterial blight
HOST: Bean
Bean leaflet with large necrotic lesions surrounded by chlorotic zones.

Bacterial blight | Bean
DISEASE: Bacterial blight
HOST: Bean (Phaseolus vulgaris)
PATHOGEN: Xanthomonas axonopodis pv. phaseoli
PATHOGEN SYNONYM: Xanthomonas campestris pv. phaseoli
SOURCE: I. Hubbeling, J. van der Wolf