DISEASE: Alfalfa dwarf
HOST: Alfalfa
Alfalfa dwarf is characterized by stunted plants (left), usually dark blue-green in color. Xylem tissues become brown, especially when exposed to air.

Alfalfa dwarf | Alfalfa
DISEASE: Alfalfa dwarf
HOST: Alfalfa (Medicago sativa)
PATHOGEN: Xylella fastidiosa
SOURCE: R. M. Davis
DISEASE: Greasy center
HOST: Poinsettia
Stem with dark cankers and copious ooze. Necrotic areas are greasy in appearance and eventually turn light tan to brown with a papery texture as the cuticle becomes detached.

Greasy center | Poinsettia
DISEASE: Greasy center
HOST: Poinsettia (Euphorbia pulcherrima)
PATHOGEN: Pseudomonas viridiflava
SOURCE: R. Raabe
DISEASE: Sudden death (Wilt)
HOST: Palm
Palm in Columbia with severe yellowing of leaves.

Sudden death (Wilt) | Palm
DISEASE: Sudden death (Wilt)
HOST: Palm (Elaeis guineensis)
PATHOGEN: Phytomonas sp.
SOURCE: R. McCoy, M. Davis