A vaccine against golden flavescence? This is the hypothesis that Sergio Marchisio, a pioneer of biodynamic viticulture in Roero, is working on. The idea is revolutionary: to obtain a quantity of depotenziated “poison”, able to immunize healthy plants. The project is coordinated by Professor Massimo Maffei of the University of Turin, Professor of Plant Physiology, Department of Life Sciences and Systems Biology. Former Director of the Department of Plant and Microbial Biology, Maffei was also a researcher in the USA at Washington State University. The idea? An experiment of extraordinary scientific interest, on paper, to find a definitive solution to the scourge of flavescence, the dreaded phytoplasmosis that affects the vine through its tiny vector, the Scaphoid Titanus, also known as the “golden flavescence buzzer”. «For our part – Sergio Marchisio says – we have made available an isolated row, reserved for this test: our hope is that an encouraging result can come out for all Italian viticulture, which is severely affected by the danger of flavescence».
As is well known, the golden flavescence is a phytoplasmosis belonging to the group of “yellows of the vine”. It affects leaves, shoots and bunches of white grapes: the phytoplasm, a parasite of plants, alters the flow of sap. The result: the leaves wither, the shoots remain herbaceous and the bunches dry out, causing the grapes to wither. For twenty years now, in Italy the fight against flavescence has included compulsory treatments. Once the presence of the disease has been ascertained, the infected plants must be eliminated. In organic farming, the fight against the Scaphoid is entrusted to active principles such as pyrethrum. In the Roero, flavescence remains a threat that comes mainly from nearby Monferrato. In the case of the Marchisio Family, then, the vines are particularly resilient: the organic strategy, combined with Rudolf Steiner’s biodynamic practice, ensures an exceptional state of health of the plants, which soon learn to defend themselves against attacks by mushrooms and parasites. However, flavescence remains an unknown factor, which frightens many winegrowers: how to defend oneself without resorting to chemistry?
«This is where our attempt starts», Sergio Marchisio explains. In the world of wine, he has made experimentation his reason for living: he has been the first to make Arneis sparkling wine, the first to make Nebbiolo in amphora, the first to produce (in Roero) also Pinot Noir in ceramic amphorae. «With Professor Maffei – Sergio explains – we started our test in 2019. Now we are in the second year of testing: it’s a matter of learning how to dose the treatments, and first of all to observe with the utmost attention the first results on the plants». The hypothetical “vaccine” is extracted from the infected ones: if it worked, transmitting to healthy vines the necessary information to repel the attack of the phytoplasm, perhaps we would reach an unprecedented turning point in the history of the biological fight against flavescence. «It’s too early to sing victory», Sergio says: «But if we have positive results, Professor Maffei will be the first to divulge them, first of all in the scientific field».