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: 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: Phony disease (Phony peach)
HOST: Peach
Tree with characteristic reduced growth. Foliage is dark green, then turns yellowish. Twigs become brittle and branches die back. Fruit are small.
Phony disease (Phony peach) | Peach
DISEASE: Phony disease (Phony peach)
HOST: Peach (Prunus persica)
PATHOGEN: Xylella fastidiosa
SOURCE: P. C. Anderson
DISEASE: Phony disease (Phony peach)
HOST: Peach
Twigs on diseased trees have shortened internodes and increased lateral branching.
Phony disease (Phony peach) | Peach
DISEASE: Phony disease (Phony peach)
HOST: Peach (Prunus persica)
PATHOGEN: Xylella fastidiosa
SOURCE: M. Davis