ICVG
Diseases: Some ongoing research
1.
Australian Shiraz Disease - In Our
Backyard
In South Australia grapevines normally become dormant in July. However, if
one looks at the vineyard just north of the ACPFG building (Hartley Grove,
Waite Campus, Urrbrae), a couple of vines with bright red leaves are seen
which have not yet gone dormant. These are not glory vines. Rather these
are the symptoms of virus infection. We have named it Australian Shiraz
Disease but it affects not only Shiraz but also Merlot and a few other
varieties. In affected vines shoots remain green and leaves are retained
until the end of the winter. Cabernet Sauvignon is resistant to it. These
vines should not be used for top working. The only other country which has
reported Shiraz Disease (SD) is South Africa. In both countries the major
virus Grapevine virus A, a Vitivirus,
has been detected in affected vines. The disease has been confirmed by Dr.
Hans Moree, Stellenbosch University, who visited the Waite Diagnostics
group on the 7th of July. However, there are some differences
between the symptoms of SD in the two countries.
Nuredin Habili* and John Randles
Waite Diagnostics, University of Adelaide nuredin.habili@adelaide.edu.au
2. Spread of grapevine leafroll disease in South Africa
Vineyards during autumn 2002/2003 in the Stellenbosch District, South Africa, showing the spread of grapevine leafroll disease
Images provided by Prof. Gerhard Pietersen, University of Pretoria - PhD thesis Anna Elizabeth Catharina Jooste, Department of Genetics University of Stellenbosch, Promoter: Prof. J.T. Burger, Co-promoter: Dr. D.E. Goszczynski).
Mealybug vectors transmit grapevine leafroll disease
Planococcus ficus under bark (2003)
Planococcus ficus under bark (2004-09)
Planococcus ficus at base of vine shoot
Images provided by Prof. Gerhard Pietersen, University of Pretoria, South Africa
ICVG secretary, CH-1272 Genolier, Switzerland: paul.gugerli@icvg.ch or webmaster@icvg.ch updated 05.11.2011