The vine looks confused: the leaves have turned red, even though
it’s only July. Looking closer, the graft, where the vitis
vinifera Syrah is attached to an American, phylloxera-resistant
rootstock, is swollen – it looks like an injured knee. Perhaps
there’s even a crack or two. The vine is not making good grapes,
and will probably die in a few years.
Syrah – or, in its Australian incarnation, Shiraz –
has been on the rise since the 90s, gaining popularity with winedrinkers
and wine critics alike. Winegrowers in the New World have responded,
and new plantings abound; in Washington, for example, the total
acreage devoted to Syrah ballooned from 50 acres to approximately
2,000 over one decade. Bottlings of Syrah are also appearing on
the shelves from unexpected places like Argentina and South Africa.
But at the same time, a mysterious ailment is attacking Syrah vineyards.
The French call it “Syrah Decline;” in California, it
goes by “Syrah Disorder.” It’s become a worldwide
problem, and the causes remain unclear.
The vine’s appearance is one thing, but Syrah Decline also
affects the wine, because the grapes do not ripen properly. The
flavors don’t materialize, the sugars remain too low, the
acidity drops, and even the color is light. Even if it weren’t
Syrah – full-bodied, darkly-colored Syrah – these grapes
wouldn’t make a good wine.
How widespread is Syrah Decline? A French report in 2004 said that
all French Syrah vineyards 15 years or younger show some signs of
the illness, with 1 to 15% of the vines infected in any given vineyard.
Some growers in the Languedoc-Roussillon area have resisted government
pressure to plant more Syrah, fearing that it could infect their
Grenache and Carignane plantings. South Africa, California, and
Oregon have also been affected; one expert estimates that in some
Central Coast’s vineyards, 25% of the Syrah vines are dying
from Syrah disorder each year. Australia remains remarkably unaffected,
so perhaps there is something in calling it Shiraz after all.
Growers are mystified. Research has uncovered some common factors
in cases of Decline across the world. Water-management is a point
of agreement: vines that become stressed by drought, salinity, or
lack of appropriate irrigation are more likely to develop symptoms
(However, over-irrigation leads to its own drop in wine quality;
some water stress leads to a concentration of flavor in the grapes.).
Similarly, most agree that vascular function – the flow of
liquids within the plant – is involved, especially at the
graft union, which sometimes seems to be choking the vine. Syrah
is more sensitive than most vines; under drought conditions, its
leaves do not close their stomata (the breathing holes on the underside
of the leaves), so more evaporation occurs and the vine loses more
However, other analyses are more contradictory. South Africa has
found substantial differences in the susceptibility of various clones,
with French clones succumbing most frequently. But a 2002 UC Davis
survey of California Syrah vineyards included a dozen clones, a
dozen rootstocks, and seven different field selections, and found
no real pattern in the Syrah Disorder occurrences. Californian research
is focusing on soil types and nutrients, especially phosphorus,
potassium, and magnesium. No virus or bacteria has been found in
association with the ailment.
While Syrah is not about to disappear from the shelves, the disease
has been distressing for winegrowers, some of whom have hoped to
jump on the train and take advantage of the grape’s popularity.
Keep an eye on prices, though, if the spread of Syrah Disorder accelerates,
costs could move up as well…except in Australia, since it
doesn’t seem much affected. Hmm…I smell a possible conspiracy
theory in the making.
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