Agriculture Reference
In-Depth Information
Fig 14.30 Advanced symptoms of papaya ringspot on leaves and
(inset) stalks.
Fig 14.31 Papaya ringspot on leaves and fruit.
Queensland, with sporadic occurrences in home gardens
and plantations.
and also provide a source of infection for further spread
of the virus.
In countries where PRSV-P is widespread, tolerant
varieties allow commercial production, although fruit
frequently develop ringspot symptoms. Resistant
varieties have also been produced by conventional
breeding using resistant
Vasconcellea
species and genetic
modifi cation using sections of the viruses' genetic
information to confer resistance.
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Management
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The disease is very diffi cult to manage. Attempts
to reduce disease levels by controlling aphids with
insecticides are ineffective.
A quarantine area was proclaimed in 1991 in Queensland
in an effort to restrict the movement of PRSV-P. Papaya
plants and cucurbit seedlings cannot be moved out of the
south Queensland quarantine zone. These restrictions
and the removal of severely affected plantations have
played an important role in preventing entry of the virus
into the major commercial production area in north
Queensland.
•
FURTHER INFORMATION
■
C h a y P ( E d . ) ( 2 0 0 0 )
Papaw information kit
. Department of Primary
Industries: Brisbane, Queensland .
P e r s l e y D M & P l of e t z R C ( 2 0 0 3 ) D i s e a s e s of f p a p a y a . I n
Diseases of
tropical fruit crops
. (Ed. RC Ploetz ) pp. 373 - 412. CABI Publishing:
Wa l ling ford .
Diseased trees and severely affected blocks should be
destroyed as they are unlikely to produce a good crop
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