Agriculture Reference
In-Depth Information
What to do if you suspect Eucalyptus or guava rust
Strict quarantine measures are in place to minimise the
risk of introducing the pathogen. If suspicious symptoms
are seen on likely hosts, contact the nearest Department
of Primary Industries or Forestry office or contact the
Plant Health Australia hotline on 1800 084 881.
for serious international implications.
Plant Disease
82
, 819-825.
Glen M, Alfenas AC, Zauza EAV, Wingfield MJ &
Mohammed C (2007)
Puccinia psidii
: a threat to
the Australian environment and economy - a review.
Australasian Plant Pathology
36
(1), 1-16.
(2008)
Eucalyptus rust
. PaDIL: Pests and Diseases
Image Library http://www.padil.gov.au.
Further information
Coutinho TA, Wingfield MJ, Alfenas AC & Crous PW
(1998) Eucalyptus rust: a disease with the potential
greatest impact on fruit production are
Phytophthora
nicotianae, P. cinnamomi
and
P. palmivora
. These species
have reasonably wide host ranges.
DISEASES CAUSED BY PHYTOPHTHORA
■
Diseases caused by
Phytophthora
affect a very wide range of
tropical and subtropical fruit crops. The genus
Phytophthora
does not belong in the fungal kingdom. It is an oomycete,
closely related to diatoms, kelps and golden brown algae
within the Kingdom Stramenopila. There are about 60 species
in the genus, all of which are plant pathogens that thrive
under humid and wet conditions. In tropical and subtropical
regions, a wide range of
Phytophthora
pathogens cause
a number of different diseases. Species of
Phytophthora
vary
greatly in their degree of host specificity. The species with
Symptoms
Symptoms of disease vary widely depending on the species
of
Phytophthora
, the host plant and prevailing
environmental conditions.
Phytophthora
species attack various plant parts including
roots and crowns, fruit, leaves, stems, f flowers and buds.
They may invade the roots and crowns of woody trees but
foliar symptoms may not become evident for months or
even years.
Life cycle
Although
Phytophthora
species have similar life cycles, the
disease cycles vary between different hosts. One of the major
features of the genus is the production of motile asexual
spores called zoospores. These zoospores are important for
the rapid spread of the pathogen. This occurs when free
water is present in the soil or on aerial plant surfaces.
Fig 2.13 Phytophthora mycelium (white fluffy growth) on fig.
Fig 2.14 Phytophthora leaf blight on citrus leaves.
