A
ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: May 8, 2007
A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases <http://www.isid.org>
[1] East Anglia - bean rust warning
[2] Brown rust - fungicide efforts
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[1] East Anglia - bean rust warning
Date: Tue 8 May 2007
Source: Farmers Weekly Interactive
[edited <http://www.fwi.co.uk/Articles/2007/05/08/103516/bean-rust-warning-for-east-anglia.html>
High levels of rust have been reported in thick winter bean
crops in East Anglia and, with the disease developing fast,
growers need to act quickly, [the chemical company] BASF has
advised.
The disease -- characterised by orange-brown pustules and small
chlorotic spots on leaves and stems -- is not normally seen
until the end of June when it is controlled with the 2nd spray,
said the firm's John Young. But, this year [2007], it needs
"serious consideration now," he said. "Severe rust infections
during flowering and pod fill can cause defoliation and
consequential loss of yield. PGRO (Processors and Growers
Research
Organisation) trials have shown a 40 per cent yield loss when
the disease is left untreated."
Young advised growers to include a rust-active fungicide
early-on in the spray programme. "As disease pressure is so
high, even in spring beans, a 2-spray programme will be needed
in many situations." Products such as the firm's Signum
(pyraclostrobin + boscalid) and Caramba (metconazole) were
particularly suited to high-risk rust situations, while Walabi
(pyrimethanil + chlorothalonil) offered an alternative in low to
moderate disease situations, he said.
[byline: Paul Spackman]
--
communicated by:
J Allan Dodds
former ProMED-mail plant disease moderator <dodds@ucr.edu>
[East Anglia can be located on the map of England at <http://en.wikipedia.org/wiki/East_Anglia>.
- CopyEd.MJ]
******
[2] Brown rust - fungicide efforts
Date: 8 May 2007
Source: Farmers Guardian [edited]
<http://www.farmersguardian.com/story.asp?sectioncode=19&storycode=9501>
With unprecedented levels of brown rust now in evidence in the
UK's wheat crop, growers are being advised to put the disease at
the forefront of their T2 fungicide campaign.
Traditionally classed as a T3 disease, the prolonged spell of
dry, hot weather has meant that brown rust has already spread
into parts of the country not seen before and is at levels
higher than can be remembered.Already this season brown rust has
extended beyond its traditional south east and East Anglian
stronghold spreading across to Hampshire, the Cotswolds, the
Midlands, and up to Yorkshire.
"Brown rust has got into the Alchemy-type varieties which have a
low resistance rating and worryingly, Robigus (which has a 9
rating). With ideal overwintering conditions, its spread has
accelerated rapidly this spring," said UAP's (United Agri
Products) technical director, Chris Bean.
"We're into T2 decisions now and growers need to consider
triazoles as important in terms of brown rust activity. They're
not the total answer and despite the fact that strobilurins may
have been dropped for septoria reasons, they have a very
significant part to play in the tank mix.
"If you're in a highly eradicant situation in terms of brown
rust then a triazole/strobilurin/morpholine mix needs to go on,
and as soon as possible," he said.
--
communicated by:
J Allan Dodds
former ProMED-mail plant disease moderator <dodds@ucr.edu>
[Bean rust (_Uromyces phaseoli_) is present in every
bean-growing area in the world. It can destroy an entire crop
and is more severe in humid areas and under moderate
temperatures. It can cause defoliation early in the season,
which reduces yield. _Uromyces appendiculatus_, a related rust
fungus, has also been reported to cause rust disease on beans.
Leaf rust, also called brown rust, on wheat is caused by the
fungus _Puccinia triticina_ (formerly _P. recondita_ f. sp.
_tritici_). Other rust diseases on wheat are stripe (yellow)
rust caused by _P. striiformis_, and stem rust caused by _P.
graminis_.
Apparently, for rust both on bean and on wheat, a much larger
than expected number of reports have been received in the UK so
early in the season. The Home Grown Cereals Association (HGCA)
(see link below) has warned growers to be vigilant.
Wheat disease management can be used at the key decision times
(T0, T1, T2 and T3) to reflect the changing risk as the season
unfolds. T reflects the growth stages of wheat referring to
tillers present at a particular time:
T0 refers to the coleoptile tiller, T1 to the tiller developing
from the first leaf, etc.
<http://www.arableds.co.uk/wdm/>
<http://www.grdc.com.au/>
<http://extension.oregonstate.edu/catalog/html/em/em8578/>
Pictures:
Bean rust, leaf symptoms:
<http://hgic.clemson.edu/factsheets/Graphics/beanpeadis/rust.htm>
Brown wheat rust, leaf symptoms:
<http://www.hgca.com/hgca/wde/IMAGES/brown%20rust1.JPG>
Links:
Home Grown Cereals Association UK:
<http://www.hgca.com/>
Other news stories on brown rust:
<http://www.fwi.co.uk/Articles/2007/05/04/103441/brown-rust-puts-pressure-on-for-early-flag-leaf-spray.html>
and
<http://www.farmersguardian.com/story.asp?sectioncode=19&storycode=9501>
Information on bean rust:
<http://www.hort.uconn.edu/Ipm/veg/htms/bnrust.htm>
and <http://www.agr.gc.ca/cal/epub/1758e/1758-0006_e.html>
Information on brown wheat rust:
<http://plant-disease.ippc.orst.edu/disease.cfm?RecordID=1138>.
- Mod.DHA]
[see also in the
archive:
Wheat stripe rust, wheat - China 20070413.1230 Wheat stem rust,
spread: FAO, Global Rust Initiative 20070414.1241
2006
---
Leaf rust, wheat - Russia (Irkutsk) 20060815.2287
2005
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Leaf rust, wheat, resistance change - India 20051201.3462
2001
---
Brown rust, wheat - Russia (E. Siberia) 20010724.1442 2000
---
Leaf rust, wheat - Australia 20001215.2187
1999
---
Leaf rust, wheat - Canada 19991015.1833] |
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