DISEASE: Periwinkle yellows
HOST: Periwinkle
Leaves with characteristic yellow and chlorotic appearance. Yellowing is first associated with veins.

Periwinkle yellows | Periwinkle
DISEASE: Periwinkle yellows
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis
DISEASE: Slippery skin
HOST: Onion
Rot progresses from the top of infected scales and eventually internal tissues rot. In early stages, the only external symptoms may be softening of the neck.

Slippery skin | Onion
DISEASE: Slippery skin
HOST: Onion (Allium cepa)
PATHOGEN: Burkholderia gladioli pv. alliicola
PATHOGEN SYNONYM: Pseudomonas gladioli pv. alliicola
SOURCE: H. Schwartz