Sustainability

Since ancient times, vines were propagated in a basic manner and did not require special treatments: winter pruning and good fertilization were more than sufficient. What changed the situation in the 19th century was the arrival of three pests from the New Continent, specifically powdery mildew, phylloxera, and downy mildew. Their appearance is attributed to the reduction in navigation times made possible by the steamship, which favored the survival on board of pathogenic entities that had coexisted peacefully with vines in America for thousands of years. The subsequent importation of disease-resistant American Isabella and Fragola grapes, intended to counteract the emerging viticultural crisis, only worsened the situation. Within 20 years, the area affected by phylloxera reached 1 million hectares, equivalent to a quarter of the total Italian vineyard area: many farmers abandoned the countryside to emigrate to cities or continue their viticultural profession in America and Australia. The phylloxera problem was then solved by grafting European vine varieties onto American vine rootstock, which is resistant to the root forms of the disease. The so-called "Bordeaux mixture" also emerged in the last twenty years of the 19th century and, in subsequent years, synthetic chemical pesticides.
An alternative and ecological path opened in the early 20th century is that of PIWI grape varieties, also known as super-organic, which are born from complex interspecific and intraspecific crossing plans aimed at obtaining an intrinsic resistance character of the plant to the main cryptogams. This is done by cutting the anthers (sacs containing male pollen) of the mother plant during flowering, and then brushing the pollen of the chosen plant for the cross onto the female part; in this way, fruits are obtained from which the seeds of the new vine will be taken and planted, which will require another 25-30 years of testing before being distributed to winegrowers. In optimal conditions, with rainfall less than 1000mm per year, these resistant varieties do not need any treatment; in any case, the use of pesticides is reduced to a maximum of three organic treatments with copper or sulfur. The quality of wines now obtained with this program is entirely comparable to other European varieties, but the economic and environmental benefits are unparalleled. However, regulatory difficulties remain (European legislation does not allow the use of resistant varieties in the production of D.O. denomination wines, and many regions have not yet authorized their cultivation) and compositional challenges (diglucosidic anthocyanin contents not compatible with European legislation for red grape varieties and for white ones, acidity control in warm central-southern environments). Currently, the cultivation of resistant grape varieties is suitable in Trentino Alto Adige, Lombardy, Friuli Venezia Giulia, and Veneto, regions in which some varieties have been registered in the regional register. Source: Riccardo Camerin, "Resistant/tolerant grape varieties - The viticultural revolution", degree thesis in Viticulture and Enology at the University of Udine