Sydney, New South Wales, Australia
August 31, 2005
University of
Sydney
Plant Breeding
Institute
Cereal Rust Laboratory
Cereal Rust Report, Season 2005
Wheat rust situation
August 2005
Colin Wellings* and Robert Park
The University of Sydney, Plant Breeding Institute
* (on secondment from NSW Department of Primary Industries)
Email:
colinw@camden.usyd.edu.au, Phone: 02-93518826
robertp@camden.usyd.edu.au, Phone: 02-9351 8806
Stripe rust
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Stripe rust samples received at PBI Rust Lab at the
end of August, 2005 |
The first sample was received from
Tarcutta (east of Wagga Wagga) in early June, and several more
arrived at the Rust Lab in late June-early July from central NSW
(Grenfell, Cowra). By mid July, further samples were received
from northern NSW (Coolah, Coonabarabran, Gunnedah). By the end
of July, stripe rust was confirmed from southern NSW (Wagga
Wagga, Finley, Deniliquin) and southern Victoria (Lake Bolac).
During August, samples were received from the same regions, and
extended north to the western Darling Downs (St George,
Chinchilla), and west to Swan Hill (Victoria). A notable record
was a sample of stripe rust received from Bauhinia (Central
Queensland) which is approximately 100km northwest of Theodore -
the previous northerly limit for stripe rust in eastern
Australia. At the time of writing, reports of stripe rust have
been received from South Australia (north east) but samples have
not been received in the lab. There have been no samples or
reports from Western Australia. The map shows locations with
confirmed stripe rust at the end of August.
Pathotype determinations have, to
date, yielded only the WA pathotype: 134 E16 A+. This pathotype
dominated in 2004 and can be expected to reoccur in 2005.
The widespread distribution of
stripe rust in eastern Australia strongly suggests that the
pathogen survived independently at many locations. Samples
appear to have been most common from earlier sown crops of
Wedgetail, Wylah and Chara. Late sown crops can be expected to
be vulnerable to cross infection from more established fields.
Given the relatively early beginning to the epidemic compared to
last year, consideration will be given in many districts to tank
mixing broad leaf herbicide with cheaper fungicide alternatives
to provide protection in the crop establishment phase. However,
it will be important to confirm disease diagnosis in relation to
the expected variety’s rust response before considering
fungicide options.
Leaf rust
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Leaf rust samples received at PBI Rust Lab at the
end of August, 2005 |
The first sample came from early
sown MacKellar and Tennant at Cooma (southern highlands, NSW) in
May. Samples from MacKellar were also received from southern
Victoria in late July. The MacKellar leaf rust pathotype appears
to be very unusual, and likely to be an exotic introduction from
overseas. The impact of this pathotype in commercial agriculture
is difficult to predict, and with this in view an isolated
disease nursery has been established to determine responses of
current wheats.
Leaf rust samples have also been
collected from several crops of Marombi in northern NSW
(Dunedoo, Liverpool Plains) in July and August. It is likely
that these will yield the Lr37 virulent pathotype,
although tests have not been completed The map shows the
distribution of leaf rust at the end of August.
Cereal rust samples may be
collected and posted in paper envelopes to the following
address:
Australian Cereal Rust Survey
Plant Breeding Institute
Private Bag 11
Camden NSW 2570
The Australian Cereal Rust Control Program is supported by
growers through the Grains
Research & Development Corporation. |
