DISEASE: Drippy nut disease
HOST: Oak
Ooze from young twig inoculated with Brenneria quercina.

Drippy nut disease | Oak
DISEASE: Drippy nut disease
HOST: Oak (Quercus agrifolia)
PATHOGEN: Brenneria quercina
PATHOGEN SYNONYM: Erwinia quercina
SOURCE: M. Schroth
DISEASE: Drippy nut disease
HOST: Oak
Ooze from infected acorn. Copious ooze drips from infected acorns, leaving sticky spots on objects under tree canopy. Infections are associated with insect oviposit wounds.

Drippy nut disease | Oak
DISEASE: Drippy nut disease
HOST: Oak (Quercus agrifolia)
PATHOGEN: Brenneria quercina
PATHOGEN SYNONYM: Erwinia quercina
SOURCE: M. Schroth
DISEASE: Varnish spot
HOST: Lettuce
Leaf with large brown and small, shiny, dark brown necrotic spots that spread in size and later dry out.

Varnish spot | Lettuce
DISEASE: Varnish spot
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Pseudomonas cichorii
SOURCE: S. Miller
DISEASE: Varnish spot
HOST: Lettuce
Advanced stage of disease with large, brown necrotic areas. They most often are along veins. Outermost leaves of the head usually are not affected.

Varnish spot | Lettuce
DISEASE: Varnish spot
HOST: Lettuce (Lactuca sativa)
PATHOGEN: Pseudomonas cichorii
SOURCE: K. Ohata, M. Goto
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry
Comparison of normal, dark cherries (in hand) with infected, immature cherries with less pigmentation.

X-disease (Western X) or buckskin | Cherry
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry (Prunus avium)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: A. Purcell, M. Davis
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry
Healthy cherry shoot (left) and stunted shoot (right).

X-disease (Western X) or buckskin | Cherry
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry (Prunus avium)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: S. Thomson
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry
Infected trees on 'Mazzard' rootstock (right) may live for years, producing fruit with symptoms. Trees on 'Mahaleb' rootstock (left) usually die rapidly in year of infection, about time of fruit ripening.

X-disease (Western X) or buckskin | Cherry
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry (Prunus avium)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: S. Thomson
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry
X-disease causes undersized, yellowish fruit. Diseased branches turn rusty red near end of season. Some defoliation occurs on diseased branches.

X-disease (Western X) or buckskin | Cherry
DISEASE: X-disease (Western X) or buckskin
HOST: Cherry (Prunus cerasus)
PATHOGEN: 'Candidatus Phytoplasma pruni'
PATHOGEN SYNONYM: Phytoplasma X-disease group
SOURCE: A. Jones