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RESULTS

(16)

DISEASE: Aster yellows

HOST: Aster

Foliar symptoms of chlorosis, malformation of leaves, and phyllody.

DISEASE: Aster yellows

HOST: Aster

Flowers with phyllody (left and center). Healthy flower (right).

DISEASE: Aster yellows

HOST: Aster

Macrosteles sp., a leafhopper vector of aster yellows phytoplasma.

DISEASE: Bacterial blast and black pit

HOST: Citrus (Lemon)

The term "black pit" refers to black lesions on fruit, which may be specks or large, sunken pits as seen here. They also may be light tan, later becoming reddish brown to black.

DISEASE: Bacterial leaf spot (Head rot)

HOST: Lettuce

Leaf with black, greasy spots that tend to be vein delimited. Lesions begin as small, angular, water-soaked lesions that coalesce, resulting in large necrotic areas.

DISEASE: Citrus canker

HOST: Citrus (Lemon)

Lower leaf with raised, corkylike lesions surrounded by dark brown halos, one of the diagnostic symptoms of citrus canker.

DISEASE: Corky root

HOST: Lettuce

Corky root causes a reduction in size of lettuce heads and root systems; susceptible cultivar (right) and resistant cultivar (left).

DISEASE: Corky root

HOST: Lettuce

Close-up of root with malformed, corky appearance and longitudinal ridges of brown tissues.

DISEASE: Corky root

HOST: Lettuce

Initial symptoms of disease are yellow lesions on taproot and main laterals. Greenish brown bands occur around roots. Root pith may become brown and hollow.