DISEASE: Crown gall
HOST: Aspen
Aspen with large, encrusted gall.

Crown gall | Aspen
DISEASE: Crown gall
HOST: Aspen (Populus sp.)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Alfalfa plant (center) exhibiting stunting and proliferation of stems. Other symptoms are small, rounded, chlorotic, often puckered leaves and a yellowish cast.

Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson
DISEASE: Witches'-broom
HOST: Alfalfa
Young plant (left) with small, numerous stems (witches'-broom). Healthy stems (right).

Witches'-broom | Alfalfa
DISEASE: Witches'-broom
HOST: Alfalfa (Medicago sativa)
PATHOGEN: 'Candidatus Phytoplasma trifolii'
PATHOGEN SYNONYM: Phytoplasma Clover proliferation group
SOURCE: S. Thomson