DISEASE: Bacterial blight
HOST: Hazelnut
Diseased young tree with discoloration of the cambium. Dieback of young twigs and branches is characteristic. Other typical symptoms are bud and twig necrosis and small, angular or round, water-soaked leaf spots.
Bacterial blight | Hazelnut
DISEASE: Bacterial blight
HOST: Hazelnut (Corylus americana)
PATHOGEN: Xanthomonas arboricola pv. corylina
SOURCE: J. Pscheidt
DISEASE: Bacterial canker
HOST: Hazelnut
Primary symptoms are failure of buds to break and withering and death of new foliage in spring. Dead leaves remain attached to limbs after normal leaf fall.
Bacterial canker | Hazelnut
DISEASE: Bacterial canker
HOST: Hazelnut (Corylus americana)
PATHOGEN: Pseudomonas syringae pv. avellanae
PATHOGEN SYNONYM: Pseudomonas avellanae
SOURCE: P. Psalidas
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Leaves with tiny lesions surrounded by large halos.
Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower
Section of a cauliflower head with discolored, infected tissues.
Bacterial leaf spot (Head rot) | Cauliflower
DISEASE: Bacterial leaf spot (Head rot)
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Pseudomonas syringae pv. maculicola
SOURCE: R. Campbell
DISEASE: Black rot
HOST: Cauliflower
Brown, necrotic, rotted areas on flower parts and typical V-shaped necrotic areas on leaf margins.
Black rot | Cauliflower
DISEASE: Black rot
HOST: Cauliflower (Brassica oleracea var. botrytis)
PATHOGEN: Xanthomonas campestris pv. campestris
SOURCE: B. Jacobsen, M. Shurtleff
DISEASE: Greening disease
HOST: Periwinkle
Healthy flower and infected flower.
Greening disease | Periwinkle
DISEASE: Greening disease
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma asteris'
PATHOGEN SYNONYM: Phytoplasma Aster yellows group
SOURCE: D. Teakle
DISEASE: Periwinkle wilt
HOST: Periwinkle
Infected plants with stunting and sparse foliage (center and right).
Periwinkle wilt | Periwinkle
DISEASE: Periwinkle wilt
HOST: Periwinkle (Vinca sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: R. McCoy, M. Davis
DISEASE: Periwinkle wilt
HOST: Periwinkle
Draeculacephala minerva, leafhopper vector of Xylella fastidiosa on plants such as periwinkle and watercress.
Periwinkle wilt | Periwinkle
DISEASE: Periwinkle wilt
HOST: Periwinkle (Vinca sp.)
PATHOGEN: Xylella fastidiosa
SOURCE: J. Clark, A. Purcell, M. Davis
DISEASE: Periwinkle yellows
HOST: Periwinkle
Leaves with characteristic yellow and chlorotic appearance. Yellowing is first associated with veins.
Periwinkle yellows | Periwinkle
DISEASE: Periwinkle yellows
HOST: Periwinkle (Vinca sp.)
PATHOGEN: 'Candidatus Phytoplasma' sp.
PATHOGEN SYNONYM: Phytoplasma (undefined)
SOURCE: R. McCoy, M. Davis