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: Brittle root
HOST: Horseradish
Dying, stunted, yellow to brown horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: C. Eastman, M. Davis
DISEASE: Brittle root
HOST: Horseradish
Close-up of stunted, yellow horseradish plants.

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: D. Sherrod
DISEASE: Brittle root
HOST: Horseradish
Horseradish with discolored internal tissues. Healthy root segment (top right).

Brittle root | Horseradish
DISEASE: Brittle root
HOST: Horseradish (Armoracia rusticana)
PATHOGEN: Spiroplasma citri
SOURCE: J. Fletcher, M. Davis
DISEASE: Leaf scald
HOST: Sugarcane
Leaf symptoms of chlorosis and white, "pencil-line" streaks.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: R. Birch
DISEASE: Leaf scald
HOST: Sugarcane
Early stage of disease with white, "pencil-line" streaks on leaf.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: R. Birch
DISEASE: Leaf scald
HOST: Sugarcane
Leaf with brownish necrotic streaks, some reddish.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: D. Teakle
DISEASE: Leaf scald
HOST: Sugarcane
Advanced stage of disease with brownish red necrotic streaks covering most of the leaf surface.

Leaf scald | Sugarcane
DISEASE: Leaf scald
HOST: Sugarcane (Saccharum officinarum)
PATHOGEN: Xanthomonas albilineans
SOURCE: S. Schenk