DISEASE: Aster yellows
HOST: Onion
Infected plants with yellowish, malformed leaves.

Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Rowe
DISEASE: Aster yellows
HOST: Onion
Onion flower with unusual symptoms (left) compared with healthy inflorescence (right). Flowers are distorted and often have abnormally long pedicels. Young leaves may have yellow streaks or a general yellowing of basal portions.

Aster yellows | Onion
DISEASE: Aster yellows
HOST: Onion (Allium cepa)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: R. Raabe
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit)
Leaves with mottled chlorosis.

Australian citrus dieback | Citrus (Grapefruit)
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: P. Broadbent
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit)
Late stage of disease. Note yellowing of leaf veins and entire leaves.

Australian citrus dieback | Citrus (Grapefruit)
DISEASE: Australian citrus dieback
HOST: Citrus (Grapefruit) (Citrus paradisi)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: P. Broadbent
DISEASE: Bacterial finger-tip rot
HOST: Banana
Cross sections of fruit with internal discoloration and rot. This disease is also known as Mokillo disease.

Bacterial finger-tip rot | Banana
DISEASE: Bacterial finger-tip rot
HOST: Banana (Musa sp.)
PATHOGEN: Burkholderia cenocepacia
PATHOGEN SYNONYM: Pseudomonas cenocepacia
SOURCE: I. Buddenhagen
DISEASE: Bacterial finger-tip rot
HOST: Banana
Longitudinal sections of fruit with internal discoloration and rot. Healthy (right).

Bacterial finger-tip rot | Banana
DISEASE: Bacterial finger-tip rot
HOST: Banana (Musa sp.)
PATHOGEN: Burkholderia cenocepacia
PATHOGEN SYNONYM: Pseudomonas cenocepacia
SOURCE: I. Buddenhagen
DISEASE: Bacterial finger-tip rot
HOST: Banana
Diseased banana hand with external discoloration.

Bacterial finger-tip rot | Banana
DISEASE: Bacterial finger-tip rot
HOST: Banana (Musa sp.)
PATHOGEN: Burkholderia cenocepacia
PATHOGEN SYNONYM: Pseudomonas cenocepacia
SOURCE: I. Buddenhagen
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Dark, rotted areas of stalk and leaves caused by systemic invasion of the pathogen.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: S. Mohan
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion
Gray-brown rot of onion after inoculation. Disease starts as small, water-soaked lesions that later develop into slimy, gray-brown rot. The disease progresses downward from the stalk and may rot the entire bulb.

Bacterial flower stalk and leaf necrosis | Onion
DISEASE: Bacterial flower stalk and leaf necrosis
HOST: Onion (Allium cepa)
PATHOGEN: Pseudomonas marginalis pv. marginalis
SOURCE: R. Gitaitis