The vineyards in Germany's middle Mosel are among the
most stunning in the world. If you stand on the Bernkastel bridge and stare
northwest, you'll notice what looks to be a 200m-high wall of vines on your right,
spanning down the river as far as the eye can see. If you glance towards the
most famous vineyard of them all, the Bernkasteler Doktor, it appears to hang
over the town itself. The quality of the Riesling wine produced by this and
neighbouring vineyards is widely recognised.
What so
special about Bernkastel site?
To begin, it has a south-facing slope in the northern
hemisphere, which ensures maximum radiation interception, especially when
paired with the steep slope. Slopes are particularly useful for radiation
interception at high latitudes more than 470 and when temperature is
limited: at about 500N and a typical July temperature of roughly 180C,
the middle Mosel met both conditions.
Second, the vines stretched from mid-slope to the
crest of the hill, providing ideal thermal qualities. Furthermore, good air
drainage considerably lowers the risk of frost. The best vineyards in Germany
are next to rivers because the sides of the twisting river valleys give steep
slopes with optimum thermal qualities; nevertheless, the temperature moderating
impact of the water and the reflection of light from the river are likely to be
the only benefits.
Another notable feature of the location is the soil,
which has a huge amount of slate on the surface. The soil is well-drained, so
it heats up quickly in the spring. Surface stone is especially important since
it reduces the likelihood of erosion. The stones absorb heat throughout the day
and re-radiate at night, resulting in less temperature change. Surface stones
can function as mulch, resulting in less water loss. Stony soils often have low
to moderate fertility, which improves the chances of vine balance. Perhaps the
proximity to the town itself provides some thermal benefit.
‘Imaginative tasters detect the
smoke from bernkastel’s chimneys in the flavor of the Docktor.’
-
Hugh
Johnson.
While this sounds wonderful there
is a downside. The expense of running these vineyards is considerable, as
everything must be done by hand. The sole mechanized process is the aerial
spraying of fungicides, which is normally done with a helicopter. However, it
seems possible that this activity will have to be halted because the residents
of the town are opposed to its usage. It's difficult to believe that pesticides
were sprayed on vineyards and, mistakenly, the town below until recently. The very
existence of traditional vineyards on steep slopes, with their high input of
labour, is under jeopardy as labour prices rise and more limitations are
imposed on aerial spraying, pesticides, herbicides, and fertiliser use. The
German government, with the backing of the people, is particularly concerned
about environmental concerns.
Vines have been planted in this region since Roman
times, and the remnants of a Roman winery were recently discovered not far from
Bernkastel. In 1989, Mosel-Saar-Ruwer's area was 55% Riesling, 22%
Muller-Thurgau, and 9% Elbling. The average yield for the entire region in the
1980s was 20 tonnes per hectare. Riesling is grown on the better locations,
while Muller-Thurgau on the poorest.
In classic middle Mosel vineyards, vines are planted
1.3m*1.3m and grown on single stakes up to 2.7m tall. Pruning is done on 2 to 4
canes with up to 12 nodes each; the canes are arched and tried to the base of
the trunk. Selected shoots (as few as four per vine) are trained and staked,
while surplus shoots are eliminated. Standard techniques include removing
leaves from surrounding bunches and tripping shoots. The steepness of the slope
prevented most mechanical activities. A high majority of small producers (less
than one hectare) cultivate their vineyards part-time.
According to Dr. Wolf Englert of the Institute for
Plant Protection in Bernkastel-Kues, there is minimal phylloxera in this
location. The soil appears to be unsuitable, and most vines are produced from
their own roots. The most often utilised rootstocks are 3309, SO4, and 5BB.
New vineyards have been planted in recent years on
mild slopes or level land, and they are trellised with rows 2.0m to 2.7m wide.
The vertically shoot-oriented trellis is similar to those seen in other regions
of Germany, with two pairs of adjustable leaf wires. These vineyards can be
mechanically harvested and maybe pruned, though the latter is very uncommon in
Germany at the moment.
Reference:
DR PETER DRY is a senior lecturer
in the Department of Horticulture. Viticulture and Oenology, The University of
Adelaide and is based at the Waite Campus.
