Fungus-resistant grape varieties
PIWI varieties

PIWI – DEFINITION AND ETYMOLOGY
IT’S ALL IN THE NAME!

PIWI is the German abbreviation for fungus-resistant grape varieties (pilzwiderstandsfähige Rebsorten; Pilz = fungus, widerstandsfähig = resistant). PIWIs are partially resistant grape varieties that are the result of methodical crossings and breeding. PIWI grape varieties display a high level of resistance to at least one fungal disease, such as Botrytis cinerea, downy mildew and powdery mildew.

The German abbreviation for these fungus-resistant varieties of grape is also well-recognised outside German-speaking regions. The abbreviation was first used by PIWI International, founded in 1988, and has now caught on around the world as a result of its catchy sounding name. Some experts like to interpret PIWI as the abbreviation for “pioneering wines” – a term that says all about these special varieties.

HISTORY
A VIRTUE BORN OUT OF NECESSITY

Long before the term PIWI was even invented, fungal resistance played a key role within the wine-growing industry. In the mid-19^th century, as a result of the phylloxera epidemic, European winegrowers began experimenting with hybrid grape varieties. These were crossings between American and European varieties with the aim of building resistance to phylloxera, progressing later to develop resistance to fungal diseases. These early crossings displayed attributes from both parent plants, resulting in a foxy aroma that was less than desirable in Europe. “Foxy” is the term used to describe the smell of fox or cat urine – as well as wet fur – which is typical of certain American grape varieties. It wasn’t until the 1970s that these characteristics could be eliminated by further breeding. The varieties that were resulted from this ongoing initiative were typically European in character and marked the beginning of the modern era of PIWI crossings.

THE BENEFITS FOR VITICULTURE
LESS IS MORE!

• One key advantage of PIWI varieties for winegrowers is the significantly reduced need to apply plant protection products in the vineyard. The number of times PIWI vineyards in Austria need to be sprayed can be reduced by two-thirds.* This not only supports an ecological, sustainable approach towards the use of natural resources, but also reduces costs in terms of machinery and personnel. People and tractors need to make less trips through the vineyard thus preserving their own health, as well as that of the soil.
• Lower costs for plant protection
• Less time- and labour-intensive
• Lower carbon emissions due to fewer tractor trips
• Less soil compaction due to fewer tractor trips

^{*PIWI Rebsortenanbau in Österreich, (Growing PIWI grape varieties in Austria) Wolfgang Renner, inObstbau und Weinbau (Pomiculture and Viticulture) 09/2022, page 30.}

DISTRIBUTION IN AUSTRIA
PIWI Qualitätswein & PIWI varietal wine

^{Source: Calculation by Austrian Wine based on figures from the Federal Ministry of Agriculture/IACS (as at 03 July 2024). Moving annual total (MAT) from July 2023 to July 2024}

PIWI vines are grown in all of the wine-producing federal states of Austria. PIWI varieties are grown on 883 ha of land, representing 2.0% of Austria’s total area under vine. In Niederösterreich (Lower Austria), 1.6% (414 ha) of vineyards are planted with PIWI grapes. In Burgenland, the share is 2.1% (243 ha), while a total of 3.3% of Steiermark’s (Styria) area under vine (170 ha) is dedicated to these varieties. The remaining 56 ha are spread between the other Austrian states.

However, a clear trend has emerged. The smaller a state’s wine-growing industry, the higher the demand for PIWI varieties. In traditional wine-growing regions with a history of viticulture dating back hundreds of years, growers continue cultivating the existing varieties. After all, vineyards are planted to last for several decades. On the other hand, regions that are planting new vineyards obviously have more room for manoeuvre. Experimenting with growing PIWI varieties is seemingly easier here – not to mention driven by the curiosity of winemakers. It is not surprising, therefore, that Tirol (Tyrol) has the highest share of PIWI vines with 54%, followed by Oberösterreich (Upper Austria) with 25%.

The Austrian wine-growing area is divided climatically into an arid (dry) zone in the north and a humid (damp) zone in the south. In the arid regions – Niederösterreich, Wien (Vienna), and northern and central Burgenland – annual precipitation is between 300 and 700 mm. Southern Burgenland and Steiermark, by contrast, have to cope with almost twice as much, with annual precipitation averaging 800–1,200 mm. As moisture increases, so, too, does the risk of fungal diseases. In Steiermark, however, this is not the only challenge that winemakers face. The steep vineyards typical of this region also complicate the application of plant protection products and increase the risk of falls and other accidents when working on the vines. This specifically explains why PIWI varieties, which require less spraying with plant protection products, are more commonplace in Steiermark.

PIWI QUALITÄTSWEIN IN AUSTRIA
AND ITS AROMA PROFILE

The following PIWI varieties are permitted for the Production of Austrian Qualitätswein:

• Blütenmuskateller
• Muscaris
• Souvignier Gris
• Donauriesling
• Donauveltliner
• Roesler
• Ráthay

PIWI VARIETAL WINES IN AUSTRIA

Austria recognises seven PIWI varieties as varietal wines (wines that have no protected designation of origin or geographic indication but lists the grape varieties or vintage on the label).

ANNEX

Legal regulations

The approval of grape varieties, including the approval of PIWI varieties, is legally regulated at two levels of jurisdiction in Austria. The first regulates the cultivation of the vines, and the second, how the wine is sold on the market.

The cultivation of PIWI varieties is determined at a federal level. Which varieties are allowed to be planted in each of the six wine-growing federal states (Niederösterreich (Lower Austria), Burgenland, Steiermark (Styria), Wien (Vienna), Kärnten (Carinthia) and Oberösterreich (Upper Austria)) is regulated by the wine law of the corresponding state. The independence of each federal state explains the differences in approach with regard to the approval of grape varieties and the range of PIWI varieties that are allowed to be planted.

The way wine is sold on the market is governed by the Austrian Wine Law. This law, which applies to all federal states, regulates the designation with which PIWI wines may be labelled. The top category of wines are labelled as “Qualitätswein” and include seven permitted PIWI grape varieties in Austria. These may be labelled with the grape variety, vintage and origin (e.g. “Steiermark”). The second category, labelled as “Rebsortenwein” (varietal wine), includes seven PIWI grape varieties. They may also be labelled with the name of the variety and vintage, together with “Austria” or “EU” as designations of origin. The third and lowest category is labelled as “Wein” (wine) and includes around 50 different PIWI varieties that may be sold without designation of variety, vintage or origin.