Written by: Tomo Jakopović
Even though we know that PIWI varieties will never replace the traditional ones, no one can — or should — ignore the fact that they are knocking ever louder at the door, and that the future of winemaking is unimaginable without these interspecific crosses playing a serious part in overall wine production.
The word PIWI is an acronym of the German term “pilzwiderstandsfähige Rebsorten”, which we translate as “varieties resistant to fungal diseases”; in English, the established term is “fungus resistant grape varieties”.
To explain PIWI varieties and the reasons they came into being, we need to dig deeper into the past and look at the problems that confronted global winemaking. In the second half of the 19th century — a time of great prosperity in viticulture and winemaking — fungal diseases, downy and powdery mildew, arrived in Europe from America (among other things). Since Vitis vinifera, today the foundation of the world’s grapevines and at that time ubiquitous across Europe and western Asia, had no resistance to the newly arrived diseases, vineyard production was seriously disrupted — and the final collapse of European viticulture came with the spread of phylloxera (a pest that attacks the vine’s roots, also arrived from America) at the end of the 19th century. In Europe’s winegrowing countries this brought catastrophic economic consequences and triggered a mass exodus of the population, mostly to the countries of the New World. Caught in a disaster of unprecedented scale, winegrowers sought a way out and, together with the scientists of the day, agreed on a strategy to revitalise viticulture. They decided to pursue a solution along two parallel tracks: developing chemical protection for vineyards, and creating crosses resistant to the newly arrived diseases.
There was success in both directions, but with accompanying problems and burdens. The first copper- and sulphur-based fungicides were soon found, solving the problem of downy and powdery mildew. Over time, conventional grape production became unimaginable without chemical protection, and vineyards grew so dependent on fungicides that resistance to them now frequently appears. Under mounting pressure and demands for organic production, chemical protection has become a serious burden on an already strained winegrowing industry. Some studies have shown that three quarters of all fungicides used in the EU are spent on viticulture, while the share of organic vineyards is significantly smaller than the organic share of other crops when compared with conventional production. It was precisely these insights — ecological awareness and the opening of an additional niche in the market — that motivated many winemakers to turn to organic production.
And now we return a hundred or so years back, to that alternative track: the creation of crosses resistant to fungal diseases and phylloxera. Scientists sought the solution by crossing the noble vine (Vitis vinifera, to retain quality) with American species (Vitis rupestris, Vitis riparia, Vitis berlandieri… where they sought resistance). Thus arose the first direct-producing hybrids such as Noah, Othello and Delaware, better known in Croatia as “tudum” and “direktor” vines. The fundamental problem was thereby solved, but the quality of the wines obtained from these varieties fell far short of expectations, and they soon disappeared from serious production, remaining mostly on small private plots. In Croatia, a legal provision still stands today prohibiting wine made from such varieties from being placed on the market.
After the relative failure of the direct-producing hybrids, general enthusiasm waned and scepticism grew about ever finding the “ideal variety”. But scientists — above all in Germany and in a few other Eastern European countries — thought differently and did not give up. Although the desire for resistance had been satisfied, quality was lacking, and new solutions had to be sought.
The breeders’ idea was to carry out multiple back-crosses — crosses with one of the parents — in order to reduce the influence of the “American side” and bring out the influence of the noble European varieties. It was a long and arduous road with an uncertain end, accompanied by the scorn and ridicule of part of the profession and the public alike. In the end, effort, vision and knowledge bore fruit: today we have a significant number of new varieties highly resistant to fungal diseases, whose quality lags barely at all behind the classic varieties.
Despite this great success, new and formidable challenges followed regarding the recognition and status of the newly created varieties. A conservative environment, misconceptions, ignorance, the strong influence of the chemical industry and the bad reputation earned by the quality of the direct-producing hybrids posed real obstacles to their spread, production and market entry. Legislators’ resistance persisted until the 1990s, when, under the persistent, well-argued pressure of German breeders, the varieties Phoenix, Staufer, Sirious, Orion, Merzling and Regent were recognised as Vitis vinifera varieties — opening the door to the development and spread of PIWI varieties.
In Croatia, PIWI varieties are appearing rather “shyly”: so far only a handful of serious producers have decided to plant vineyards with these disease-resistant varieties.
The greatest challenges in this field are yet to come, once the first serious quantities of such wines reach the market — because lack of awareness, reluctance to accept the new and consumers’ conservative instincts do organic producers no favours. However, through the synergy of winemakers, restaurateurs, retailers and the media, public interest can be sparked, the market opened and the placement of these wines made easier.
Piwili!
Photo: Pexels
