Slideshow

How to cultivate vines in Japan

08 October 2018 By Patrick Schmitt

Japanese viticulturalists face some of the most challenging conditions for vine growing in the world, but they have developed some characteristically novel ways to deal with them.

General manager of Suntory’s Tomi no Oka winery, Fumio Shonai

As I wrote last week in an introduction to the Japanese wine scene, for the most part, the country’s vineyards are found in a sub-tropical environment, marked by summertime rains that conflict with the growing season, with associated problems of rot and swollen berries.

But the producers’ response to such a challenge sets new standards for precision viticulture. Nothing, it seems, is too much trouble for the Japanese vineyard manager.

And, over the following pages, I have compiled some of the techniques used to tackle the climatic challenges – which could be a source of ideas for vineyard management elsewhere, even if you don’t face such humid conditions.

Waxed paper protection

Pink-skinned Koshu is protected from summer rains with waxed-paper hats

The most common technique is to cover each bunch with two pieces of waxed paper stapled together, creating, in effect, a little hat to shield the grapes from the rain. It’s a neat and pretty solution, but expensive, adding around 10% more per hectare to the cost of managing a vineyard.

And according to Yasuaki Katsuno, head viticulturist at Château Mercian, the waterproof covers also protect the bunches from potential fungal infections from decaying leaves – most vineyards in Japan are trained in pergolas, selected to maximise airflow while sheltering the bunches with a canopy of leaves.

Shielding Merlot at Chateau Mercian in Nagano

Plastic sheeting

One method to protect vines from rainfall at Tomi No Oka in Yamanashi

Although highly effective, due to the high cost of attaching miniature coverings for every bunch on the vine, some producers resort to plastic sheeting as a solution.

Where pergola training is in place, this can take the form of large structures supporting giant polytunnels, which may protect the vines from rainfall, but also restrict airflow and therefore increase humidity around the vine.

However, where a VSP (vertical shoot positioning) trellis design has been used, producers tend to use a system that shields each row of vines from the rain.

Depending on how exposed the site is and the direction of the wind, such protection is either above or within the vines (see above and below at Tomi No Oka estate in Yamanashi.

And another at the same property

Fan circulation

Fans at Goichi Winery to aid circulation

One winery, Goichi Wine in the Nagano Prefecture, has even installed giant fans that start automatically when the humidity exceeds a certain level to improve air circulation in the vines.

Such a technique is part of a government-funded trial to see if it helps reduce disease incidence in the berries, although producers are doubtful that it is effective.

At the same winery, a line of specially-designed Japanese-manufactured sprayers lie in wait. At the front is an air-conditioned water-proof cab, and at the back, a mechanism to spray fungicide to the bunches above.

And here are some sprayers at the same winery, designed to pass under the pergolas and emit fungicides from behind

Sub-surface drainage

Grace’s Misawa Vineyard in Akeno

In combination with such protection from above, certain producers resort to ways to reduce surface water, be it by creating deep drainage ditches, installing pipes or digging in gravel.

All three techniques have been employed at the top site for Koshu from Grace – the Misawa Vineyard in Akeno.

Pergola training

Pergola trained vines at Iwanohara Winery

Then there’s the most widely practised training regime – the high pergola, selected to maximise airflow while sheltering the bunches with a canopy of leaves.

Nevertheless, the use of wire-trained vertical shoot positioning systems is becoming more commonplace, because with increased exposure comes greater sugars and ripeness levels – necessary particularly with the use of international red grapes such as Merlot, Pinot Noir and Cabernet.

Takahiko Saga with his organically-grown Pinot Noir at Hokkaido’s Domaine Takahiko

Hybrid grapes

Koshu at Lumiere Winery

While the techniques outlined above allow Japanese producers to harvest healthy grapes using international varieties, the majority of plantings in Japan employ hybrid grapes, bred for their disease-resistance in this generally wet climate.

Delaware, Campbell Early, Niagara, and Concord were the most popular hybrid grapes at the beginning of the twentieth century, but today, in terms of a quality solution for reds, Muscat Bailey A is the top pick, and yields fruity results with some of the characters of a light Beaujolais.

With a rather clunky name, the Japanese commonly refer to it as just ‘Baily A’, although I think it would be better called ‘MBA’.

However, it is Japan’s hybrid white grape called Koshu that’s causing a stir among wine connoisseurs in the country, and beyond.

In the vineyard, key to this grape’s successful performance in Japan – where it has been cultivated as a table grape for more than 1,000 years – is its ability to withstand moisture-induced disease, thanks to its thick skins, which are light pink. On the table, its ability to win favour hails from its delicate, appealing combination of flavours, from citrus to peach, as well as its affinity for ageing on its lees, and even, when done with sensitivity, in barrels.

Although it is almost exclusively found in Japan, owner of Grace Wine, Shigekazu Misawa, told me that Koshu is found in Europe, after Rheingau producer Schonleber Blumlein planted a vineyard in 2003.

Misawa recalled that in the troubled 2006 vintage in Germany, where a wet summer led to the rapid spread of rot in Riesling, the Koshu grapes at this estate were picked clean and healthy.

Finally…

Mr Hayashi from Goichi Wine, who has developed his own pergola training technique following advice from viticulturist Dr Richard Smart. It has since been dubbed the Hayashi-Smart System.

Mitigating such climate-related challenges are, notably, the choice of sites for planting grapes for making wine. In particular, wine regions Yamanashi and Nagano – which together account for more than 50% of Japan’s wine production – are generally drier parts of the country, shielded by mountain ranges that act as a barrier to sustained summertime rains, as well as the combination of high winds and heavy precipitation that come with typhoons – weather events that can clash with grape harvesting. So, while Tokyo on the coast is subject to 2,000mm of rainfall, inland, Yamanashi, in the shadow of Mount Fuji, receives less than half that total.

On the northern island of Hokkaido, the climate is more temperate, but picking must be performed before the arrival of heavy snowfall from late October onwards – requiring producers to lay vines flat after harvesting to insulate them from freezing temperatures above the snow line, and prevent the trunks from snapping under the weight of powder.

In all regions, vineyards are generally located on more free-draining slopes, comprising a mix of soil types, from porous gravels to volcanic-sourced geology.

Also, there’s an important human factor in the management of Japanese viticulture. The wine industry operates like Champagne in the sense that the growers are separated from the producers.

Indeed, the Japanese wine industry comprises lots of farmers, who own the vineyards and manage the harvest, and then sell their produce to a few major wine producers, who often have long term contracts with the growers.

Such farmers are both hardy and fastidious, two traits that are necessary in this challenging climate for viticulture. Indeed, as one explanation for such growers’ dedication to the land despite the difficult conditions, I was told that many of them are direct descendants of Samurai warriors.