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FLAVESCENCE DOREE, GRAPEVINE - SWITZERLAND: UPDATE
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International Society for Infectious Diseases
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Date: 26 Jan 2010
Source: Proplanta [in German, trans. & summ. ModDHA, edited]
<http://www.proplanta.de/Agrar-Nachrichten/agrar_news_themen.php?SITEID=1140008702&Fu1=1264487876>
Flavescence doree in Swiss vineyards in 2009
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In 2009, flavescence doree [FD] was rife in Ticino vineyards [the part
of Switzerland bordering Italy - Mod,JW]. In the rest of Switzerland,
this disease has not yet been recorded, although the insect vector
occurs in the cantons along Lake Geneva (Geneva, Vaud and Valais).
Scientists at Agroscope Changins-Wadenswil [ACW] confirmed the
presence of FD in Ticino, especially in Sottoceneri [region]. In
Sopraceneri, however, the disease has almost disappeared.
Since its emergence in the canton of Ticino in 2004, 2 districts each
have been hit in each of the 2 regions. In 2009, one district in
Sopraceneri was FD-free, while 6 new cases were recorded in
Sottoceneri. The improved situation in Sopraceneri since 2008 is the
result of past information campaigns, culling of sick plants and
control of the vector.
The previous main centres of infection seem to have stabilised, but
vigilance is vital. As of November 2009, there were a total of 101
cases of FD with only 6 of them in Sopraceneri (Locarno). In
Sottoceneri, the most worrying district is Lugano with 13 of 70
communities affected. Merlot, Pinot Noir and Chardonnay are the most
commonly affected varieties but not necessarily the most sensitive.
At present, control measures in Ticino include destroying plants
diagnosed with FD, compulsory insecticide sprays against _S. titanus_
in affected areas, and thermotherapy treatment of propagation material
produced in the area.
--
Communicated by:
ProMED-mail
<promed@promedmail.org>
[Flavescence doree (FD) is the most important and destructive
phytoplasma disease of grapevines due to its fast rate of spread
within vineyards. The disease was 1st reported in 1954 in France and
is spreading in southern Europe. FD was thought to have been
introduced from the USA, the home of its vector. It is caused by a
phytoplasma (_Ca._ Phytoplasma vitis) belonging to the 16SrV (elm
yellows) group. The only known natural hosts are _Vitis vinifera_ and
interspecific hybrids, but some wild American _Vitis_ species may be
asymptomatic carriers.
Symptoms usually appear in late spring and may include shortened
internodes, stunting, leaves with downward rolled margins and drooping
shoots. Leaves turn yellow in white grape cultivars and red in red
ones. Leaf necrosis and bark splitting may also develop, the crop is
severly reduced and some vines die, usually in the year following
infection. The survivors continue to harbour the pathogen but appear
symptomless (latent infections) unless they are re-infected.
FD is spread by the vine leafhopper _Scaphoideus titanus_ and through
infected propagation material. Symptomless budwood can carry both eggs
of the vector and the pathogen. Reliable diagnosis in both symptomatic
and asymptomatic host tissue (preferably by molecular methods) is
vital for disease management which may include pathogen exclusion,
certification of clean propagation material and removal of infected
plants (pathogen reservoirs). Insecticides can reduce vector numbers.
The phytoplasma may be eliminated by treating dormant canes with water
at 45 - 50 degrees Celsius (the heat therapy mentioned above).
There are several phytoplasma diseases of grapevine in different parts
of the world. These diseases are collectively referred to as grapevine
yellows.
Maps
Switzerland:
<http://www.idsia.ch/wea2003/map_switzerland.gif> and
<http://healthmap.org/r/00v2>
Swiss cantons:
<http://www.about.ch/cantons/index.html>
Tessin regions:
<http://upload.wikimedia.org/wikipedia/commons/1/11/Karte_Kanton_Tessin_Bezirke.png>
Pictures
Flavescence doree symptoms on grapevine:
<http://www.proplanta.de/Agrar-Nachrichten/proplanta_header.php?katalogid=1264420011>,
<http://www.grapes.msu.edu/images/images/photos/flaveLv.jpg> and
<http://www.agf.gov.bc.ca/cropprot/grapeipm/images/fd_chardonnay.jpg>
FD affected vineyard:
<http://www.inra.fr/hyppz/IMAGES/7032991.jpg>
FD symptoms photo gallery:
<http://photos.eppo.org/index.php/album/82-phytoplasma-vitis-flavescence-doree-phyp64->
_S. titanus_ vector:
<http://www1.pms-lj.si/animalia/media/Scaphoideus-titanus/Scaphoideus-titanus_049a_GSeljak.jpg>
(adult) and
<http://www.inra.fr/hyppz/IMAGES/7032992.jpg> (pupa)
Links
Information on FD:
<http://www.fera.defra.gov.uk/plants/publications/plantHealth/documents/QIC54.pdf>,
<http://www.fao.org/docrep/T0675E/T0675E0a.htm#Flavescence%20dor%C3%A9e> and
<http://chaos.bibul.slu.se/sll/eppo/EDS/E-GVFDXX.HTM>
Information on _S. titanus_ vector:
<http://www.inra.fr/hyppz/RAVAGEUR/6scatit.htm>
Grapevine phytoplasma diseases, including FD:
<http://www.agf.gov.bc.ca/cropprot/grapeipm/phytoplasma.htm> and
<http://www.inspection.gc.ca/english/plaveg/pestrava/graphy/tech/graphye.shtml>
FD phytoplasma taxonomy:
<http://www.uniprot.org/taxonomy/131152>
Phytoplasma resource centre:
<http://plantpathology.ba.ars.usda.gov/phytoplasma.html>
ACW:
<http://www.agroscope.admin.ch/aktuell/index.html?lang=en>
- Mod.DHA]
[see also:
2008
----
Aster yellows phytoplasma, grapevine - South Africa: update 20080519.1666
Grapevine diseases - Tunisia, Canada 20080212.0569
2006
----
Bois noir phytoplasma, grapevine - Canada (BC): 1st report 20061209.3473
2004
----
Stolbur phytoplasma, grapevines - Ukraine: 1st report 20041123.3134
Grapevine flavescence doree, status - France 20040105.0042
Grapevine yellows phytoplasmas, new data, EPPO 20040104.0037
2003
----
Phytoplasmas, fruit trees, grapevine - Albania 20030819.2083
Grapevine flavescence doree phytoplasma - Italy & Serbia 20030717.1754
Elm yellows phytoplasma, grapevine - Serbia 20030523.1261
Grapevine yellows - France 20030315.0641
2002
----
Bois noir phytoplasma, grapevine - Switzerland 20020712.4739
Bois Noir phytoplasma, grapevine - Lebanon 20020711.4723
1999
----
Grapevine bois noir epidemiology - France 19990718.1212]
....................dha/ejp/jw
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