A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
Date: 9 Apr 2009
Source: Farmers Guardian [edited]
<http://www.farmersguardian.com/story.asp?sectioncode=19&storycode=25509>
Cold weather fails to halt rust infection
Rust infections are starting to appear in winter wheat crops in
some areas, growers are being advised. Despite the cold winter
-- which was thought may have killed off infections -- early
reports of yellow rust are starting to emerge from several parts
of the country.
So far, these include Lincolnshire and various parts of the
Midlands, but others may be affected, says Syngenta disease
specialist Rod Burke. "Although we don't yet know how these
early infections will develop, it's important growers factor
them into their early season disease control."
Plant pathologist Bill Clark, director of Broom's Barn research
centre, has also picked up early rust reports. Although it can
be difficult distinguishing between yellow and brown rust at
this time of the season disease is certainly present, so it's
not alarmist to consider rust along with septoria at the April
spray timing, he says.
In the Midlands, agronomist Chris Page has found yellow rust on
the variety Robigus in Northamptonshire. "It's not surprising
given the conditions and the variety. Although it's been very
cold and dry, the recent milder weather has helped the disease
develop. Moisture from overnight dews or rain will continue to
provide optimum conditions for development."
On backward crops, growers will need to be extra vigilant with
crop inspections.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[Stripe rust, also called yellow rust, of cereals is caused by
the fungus _Puccinia striiformis_ var. _striiformis_. It causes
yellow leaf stripes and stunting of plants with yield losses of
40 to 100 percent. It affects wheat, some barley varieties,
triticale, and a number of wild grasses. Spores are wind
dispersed in several cycles during the cropping season. Grasses
and volunteer crop plants may generate a "green bridge"
providing inoculum for the next crop cycle.
Disease monitoring is important so timely action can be taken to
limit the spread of the pathogen as well as build-up of
inoculum.
Disease management includes the use of resistant varieties,
fungicide applications, and control of volunteer crops.
New pathogen strains with increased virulence have been reported
in recent years from wheat growing areas in Europe, North
America, Australia, India and are also suspected to emerge in
China. National and collaborative resistance breeding programmes
have been set up in response.
The other wheat diseases mentioned above are leaf rust, also
called brown rust, caused by the fungus _Puccinia recondita_;
and the septoria complex caused by the fungi _Mycosphaerella
graminicola_ (previously _Septoria tritici_) and _Phaeosphaeria
nodorum_. These pathogens also affect photosynthetic ability of
the host and cause yield losses. (For more information see
previous ProMED-mail posts in the archives.)
Maps of UK:
<http://www.lib.utexas.edu/maps/europe/united_kingdom.gif>
and <http://healthmap.org/r/008E>
Pictures
Stripe rust on wheat leaf:
<http://utextension.tennessee.edu/fieldCrops/wheat/Wheat_photos/Wheat_StripeRust.jpg>
and
<http://www.grdc.com.au/uploads/images/Stripe%20rust%20Colin%20Wellings%20ACRCP.JPG>
Stripe rust on wheat head:
<http://cril.cimmyt.org/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=950&g2_serialNumber=2>
Stripe rust on resistant and susceptible wheat cultivars:
<http://www.oznet.ksu.edu/path-ext/factSheets/wheat/Wheatimages/wheats1.jpg>
Barley with stripe rust:
<http://www.ipmcenters.org/cropprofiles/docs/Graphics/WAbarleyStripeRust.jpg>
Ryegrass with stripe rust:
<http://plant-disease.ippc.orst.edu/plant_images/ryegrass_stripe_rust.jpg>
Links
Information on wheat stripe rust:
<http://pnw-ag.wsu.edu/smallgrains/Stripe%20Rust.html>,
<http://www.ars.usda.gov/Main/docs.htm?docid=9918&pf=1&cg_id=0>,
<http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/158964/stripe-rust-in-wheat.pdf>
and
<http://www.oznet.k-state.edu/path-ext/factSheets/Wheat/Wheat%20Stripe%20Rust.asp>
Stripe rust management:
<http://www.grdc.com.au/uploads/documents/striperustmgt.pdf>
and <http://www.ipm.ucdavis.edu/PMG/r730100511.html>
_P. striiformis_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=427989>
- Mod.DHA]
[see also
in the
archive:
Stripe rust, wheat - India: new strain 20090329.1216 Wheat rusts
- Kenya, India, Australia 20090312.1019 Rust diseases, wheat,
mustard - India: (JK) 20090305.0897 Stripe rust, wheat - China
20090208.0579
2008
----
Stripe rust, wheat - Australia (02): (VIC) 20080916.2897 Stripe
rust, wheat - Australia: (QLD, NSW), alert 20080716.2156 Cereal
rusts - Australia: (NSW) 20080624.1945 Wheat stripe rust,
oilseed rape sclerotinia - China 20080408.1297 Stripe rust,
wheat - Denmark: new strains 20080211.0542
2007
----
Stripe rust, wheat - Australia (SA): new strain 20070921.3135
Stripe rust, wheat & wheat streak mosaic - Australia (SA, WA)
20070830.2860 Fungal diseases, wheat & pulses - Australia (SA)
20070821.2729 Ergot & stripe rust, cereals - USA (MT)
20070706.2144 Stripe rust, wheat - USA, Australia 20070614.1950
Wheat stripe rust, wheat - China 20070413.1230
2005
----
Stripe rust, wheat - Australia 20051031.3173 Wheat stripe rust -
USA (FL) 20050601.1521
2004
----
Wheat stripe rust - Australia (NSW) 20040928.2683 Wheat stripe
rust - Australia (NSW): alert 20040810.2215 Wheat stripe rust -
China 20040429.1191
2003
----
Wheat stripe rust, new strains - Australia (SA) 20030930.2465
Wheat stripe rust - Australia (WA) 20030624.1553 Wheat stripe
rust, first report - USA (Florida) 20030516.1220
2002
----
Wheat stripe rust - Australia (Western): alert 20020831.5198
1999
----
Stripe rust, barley - Australia (Victoria & NSW) 19991116.2043]
