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: Greening disease
HOST: Periwinkle
Healthy flower and infected flower.

Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: D. Teakle
DISEASE: Greening disease
HOST: Periwinkle
Diseased plants with phyllody and greenish yellow leaves.

Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Vinca minor)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: E. Braun
DISEASE: Greening disease
HOST: Periwinkle
The disease causes virescence and phyllody, distorted and discolored leaves, and greening of flowers.

Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Catharanthus roseus)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: W. Borth
DISEASE: Xanthomonas leaf blight
HOST: Onion
This was the first photo of onion leaf blight, which was considered a controversial finding for 10 years until an outbreak occurred in the West Indies.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Diseased leaf with necrotic internal tissues.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: A. Alvarez
DISEASE: Xanthomonas leaf blight
HOST: Onion
Onions with brown, necrotic, blighted leaves.

Xanthomonas leaf blight | Onion
DISEASE: Xanthomonas leaf blight
HOST: Onion (Allium cepa)
PATHOGEN: Xanthomonas axonopodis pv. allii
PATHOGEN SYNONYM: Xanthomonas campestris pv. allii
SOURCE: H. Schwartz