RESULTS

(3)

FILTER

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: Larkspur virescence

HOST: Larkspur

Two diseased plants with stunted and small leaves, lack of flower coloration, and bunched flower buds. Healthy plant (left).

Larkspur virescence | Larkspur

DISEASE: Larkspur virescence

HOST: Larkspur (Delphinium sp.)

PATHOGEN: 'Candidatus Phytoplasma asteris'

PATHOGEN SYNONYM: Phytoplasma Aster yellows group

SOURCE: R. Raabe

DISEASE: Western wetwood

HOST: Elm

Spokelike, discolored extensions that expanded into sapwood, following an injection with a fungicide. The causal agent is not known but symptoms are associated with bacteria and yeast.

Western wetwood | Elm

DISEASE: Western wetwood

HOST: Elm (Ulmus americana)

PATHOGEN: Causal agent unknown

SOURCE: W. Sinclair