Recognizing Exotic Diseases of Citrus

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Recognizing Exotic Diseases of Citrus
Jeff Lotz, FDACS, FL
S. E. Halbert, FDACS, FL
The disease begins with chlorotic sectoring in
the tree branches thus the name Huanglongbing
(yellow shoot).
The disease is spread by psyllids heavy
infestations with nymphs result in an obvious
waxy excrement.
Citrus leprosis is caused by a virus spread by
Brevipalpus sp mites. Control of mite vectors and
trimming of infected branches account for 25 of
the cost of citrus production in Brazil left
untreated the disease will kill a tree in 3 years.
Fruit from infected trees drops early and has a
bitter taste. The leaves have a blotchy mottle,
often with a yellow mid-ribs.
Brevipalpus mites on a citrus leaf
Fruit remains green on the basal end, seed is
aborted in affected fruit, and the fruit may be
lopsided.
HUANGLONGBING (Citrus Greening) present in Florida
Lesions occur on twigs, leaves, and fruit.
Leprosis-affected fruit falls early
CITRUS LEPROSIS
Citrus Canker
(Xanthomonas axonopodis pv citri) Affects limes,
grapefruit, and trifoliates most severely.
Causes lesions on leaves, twigs, and fruit,
causing fruit drop. Spread by rain-driven wind
and infested equipment. A quarantine disease
present in Florida.
Infected trees are chlorotic and become stunted
and decline. Leaves have interveinal chlorosis
with gum deposits on the underside.
Report anything suspicious to your State
Department of Agriculture
Sharpshooter insects spread the disease.
CITRUS VARIEGATED CHLOROSIS (CVC) caused by
Xylella fastidiosa
Poster prepared by the USDA ARS National Clonal
Germplasm for Citrus and Dates Riverside, CA
92507 Richard Lee rivrl_at_ars-grin.gov Phone 951
827 4399