DISEASE: Aster yellows
HOST: Squash
Diagnostic characteristics for the disease are yellowing of young leaves, proliferation of secondary shoots, and rigid erect habit. Leaves are misshapen and smaller than normal and have stiff, thick laminae.

Aster yellows | Squash
DISEASE: Aster yellows
HOST: Squash (Cucurbita sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: S. Miller
DISEASE: Bacterial heart rot
HOST: Palm
Palm with advanced stage of heart rot. Symptoms of mature palms include rapid browning and desiccation of foliage, rot of roots and buds, and aborted fruits.

Bacterial heart rot | Palm
DISEASE: Bacterial heart rot
HOST: Palm (Cocos nucifera)
PATHOGEN: Phytomonas sp.
SOURCE: R. McCoy, M. Davis
DISEASE: Cane blight
HOST: Rose
Rose with blighted necrotic cane.

Cane blight | Rose
DISEASE: Cane blight
HOST: Rose (Rosa sp.)
PATHOGEN: Pseudomonas syringae
SOURCE: S. Mohan
DISEASE: Crown gall
HOST: Rose
Rose with galls near soil line.

Crown gall | Rose
DISEASE: Crown gall
HOST: Rose (Rosa sp.)
PATHOGEN: Agrobacterium tumefaciens
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: M. Goto
DISEASE: Hairy root
HOST: Rose
Hairy root symptoms of many fibrous roots (right). Noninfected root (left).

Hairy root | Rose
DISEASE: Hairy root
HOST: Rose (Rosa sp.)
PATHOGEN: Agrobacterium rhizogenes
SOURCE: R. Raabe
DISEASE: Hairy root
HOST: Rose
Crown gall (left) and hairy root (right) caused by Agrobacterium tumefaciens and A. rhizogenes, respectively. Healthy root (center).

Hairy root | Rose
DISEASE: Hairy root
HOST: Rose (Rosa sp.)
PATHOGEN: Agrobacterium rhizogenes
PATHOGEN SYNONYM: Rhizobium sp.
SOURCE: M. Schroth
DISEASE: Lethal yellowing
HOST: Palm
Palm with dark necrotic inflorescence.

Lethal yellowing | Palm
DISEASE: Lethal yellowing
HOST: Palm (Cocos nucifera)
PATHOGEN: 'Candidatus Phytoplasma palmae'
PATHOGEN SYNONYM: Phytoplasma Coconut lethal yellowing group
SOURCE: N. A. Harrison
DISEASE: Lethal yellowing
HOST: Palm
Palm with close-up of diseased yellow spear leaf.

Lethal yellowing | Palm
DISEASE: Lethal yellowing
HOST: Palm (Cocos nucifera)
PATHOGEN: 'Candidatus Phytoplasma palmae'
PATHOGEN SYNONYM: Phytoplasma Coconut lethal yellowing group
SOURCE: W. Sinclair
DISEASE: Lethal yellowing
HOST: Palm
Progression of lethal yellowing symptoms. Older fronds of coconut palm turn yellow, followed by yellowing of younger ones near center of crown.

Lethal yellowing | Palm
DISEASE: Lethal yellowing
HOST: Palm (Cocos nucifera)
PATHOGEN: 'Candidatus Phytoplasma palmae'
PATHOGEN SYNONYM: Phytoplasma Coconut lethal yellowing group
SOURCE: W. Sinclair