Since Antiquity, the vine was propagated in an elementary way and did not need special treatments: Winter pruning and good fertilizing were more than enough. To change the situation in the Nineteenth century is the arrival of three parasites from the New Continent, specifically Powdidium, Phylloxera and Peronospora. Their appearance is attributed to the reduction of the sailing time made possible by the steamboat, which favoured the survival aboard the pathogenic entities that in America lived peacefully with the vine for thousands of years. The subsequent importation of American grape Isabella and disease-resistant Strawberry, apt to counteract the nascent wine crisis, made the situation worse. Within 20 years the surface affected by phylloxera came to 1 million hectares, amounting to a quarter of the total Italian wine-growing area: Many peasants abandoned the countryside to emigrate to the city or continue the wine-growing profession in America and Australia.Il problem of Phylloxera has found a solution grafting the European vine varieties on rootstock of American vine, resistant to the radicicultural forms of the disease. In addition, the so-called “Bordolese Mash” Was born in the last twenty years of the Nineteenth century and, in the following years, phytosanitary products of chemical synthesis.
An Alternative and Ecological road open at the beginning of the Twentieth century is that of the PIWI vines, also called super-bio, which come from complex interspecific and intraspecific cross-breeding plans to obtain an intrinsic resistance character of the plant to Major Cryptogames. We proceed by severing the anens (pockets containing the male pollen) of the mother plant, in the flowering phase, and then brushing on the female part the pollen of the plant chosen for the crossing; This results in the fruits from which the seeds of the new grape will be collected and planted, which will require a further 25-30 years of testing before it can be distributed to the vine-growers. In optimum conditions, with rainfall of less than 1000mm per year, these resistant vines do not need any treatment; However, the use of phytochemicals is reduced to a maximum of three biological treatments with copper or sulphur. The quality of the wines today obtained with this programme is completely comparable with the 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 wines under denomination D.O. And many regions have not yet authorized their cultivation) and challenges of a compositional nature (the contents of Diglucosidic anthocyanins not compatible with European standard for red berry varieties and for white ones the control of acidity in environments Warm south-central). Currently, the cultivation of resistant vines is suitable in Trentino Alto Adige, Lombardy, Friuli Venezia Giulia and Veneto, regions in which some varieties have been entered in the regional register. Source: Riccardo Camerin, “resistant/tolerant Vines – The winemaking Revolution”, thesis in Viticulture and Oenology at the University of Udine