Not only a barrier against drought and limestone but a vehicle for superior wine quality: the latest surprising discovery about M-selected rootstocks.
The research team from the University of Milan led by Professors Attilio Scienza and Lucio Brancadoro with support from Winegraft companies-reverses an old belief that has accompanied the spread of rootstocks since the phylloxera crisis and offers a whole new picture to fully understand the potential of the M-series that is beginning to be in demand by all the world’s major wine-growing areas.
After more than twenty years of experimentation and microvinifications in ten different production areas of the country, from Piedmont to Sicily, the University of Milan team has demonstrated that the “4 musketeers” of the M series are able to bring the vine to better productive performance in all the different aspects that determine the quality of the grape and therefore of the wine: vigor and production of the strain, technological, phenolic and aromatic maturation of the grapes.
Marcello Lunelli’s comment
“The scope of this latest research from the University of Milan is truly revolutionary. – commented Marcello Lunelli, president of Winegraft the company that brings together 9 of the country’s most important wineries (Ferrari, Zonin, Banfi Società Agricola, Armani Albino, Cantina Due Palme, Claudio Quarta Vignaiolo, Bertani Domains, Nettuno Castellare, Cantine Settesoli ) chand for the past ten years has supported the development of research on M rootstocks, multiplied and distributed exclusively by Rauscedo Cooperative Nurseries – because it changes the historical view we have always had of rootstocks. From now on, we should no longer view them as just a “barrier against” phylloxera, drought, etc., but as an efficient biological tool “to” achieve superior grape and thus wine quality.”
The word from Attilio Scienza
“We were finally able to demonstrate that even in viticulture, as is now accredited in other areas of tree crops. Ihe rootstock is also a valuable vehicle for improving production quality. It took two decades of field experimentation and articulated microvinification to arrive at the result. È objectively more difficult in viticulture to carry out in-depth investigations into the effect of rootstock on grape quality because of the complex interactions between it, the growing environment and different grape varieties.”
Goal achieved, comments Lucio Brancadoro
But the goal has been achieved. “The significant amount of information we have acquired in the course of this long experimental work. now allows us to have a clearer view of the direct effect of rootstock choice. In the production-quality performance of the vine and grapes, with reference to the quality of the wines obtained. In particular – Brancadoro continues – in the different grafting combinations operated in various fields of comparison between Ms and other traditional rootstocks. Among those most widely used in our country, it emerged not only the extreme adaptability of Ms to the different environments of Italian viticulture but also how, through adjusting the adaptive responses of the vine to different environmental conditions. M rootstocks are an important driver of quality results. By responding more efficiently to increasingly extreme abiotic stresses due to climate change, Ms allow a more favorable ripening course of grapes, a premise for superior quality of oenological results.”
Phenolic concentration in reds and higher acidity levels for sparkling wines
In detail, field trials and sensory analysis on wines obtained in experimental fields have shown for Cabernet Sauvignon grafted on Ms better production results in general, balanced by good vigor and with higher than average sugar values, a high parameter that we also find in Chardonnay, planted in comparison fields in Franciacorta and Trento doc, combined with higher levels of titratable acidity (of malic acid in particular) and lower pH, a determinant element for quality sparkling wine production. Sensory analysis of wines made from Chardonnay grafted with M’s raised in Franciacorta showed higher levels of acidity and a complex flavor profile. This enhances tropical fruit notes:. From the olfactory point of view, these wines were found to be more intense and, on taste testing, with greater acidity, savoriness, structure and persistence.
In addition to technological parameters, it was seen how much the rootstock also affects the accumulation of polyphenols during ripening, a crucial aspect in the quality of red wines. In the comparison fields in combination with different red grape varieties – Nero d’Avola, Cabernet Sauvignon and Sangiovese – higher levels of total polyphenols in the grapes, a brighter hue of the coloring substances accompanied by their greater accumulation and concentration were found, particularly for the non-decolorizing anthocyanin fraction, which facilitates better color persistence during wine aging. A final aspect relevant to sensory analysis.
emerged from the experimentation, is that of the aromatic composition of the grapes that M rootstocks condition in a certain way because, by influencing a different response to environmental conditions, they also have direct effects on the secondary metabolism of the vine.
The evidence on Chardonnay and Sangiovese
“This aspect is little studied to date because of the difficulties of analyzing the large number of aromatic compounds present in wines obtained from different grafting combinations – explained Lucio Brancadoro further -. In our tests carried out on Chardonnay and Sangiovese grapes, however, beyond the details of the increases in the individual compounds found (volatile acids, thiols, ethyl esters, phenols, norisoprenoids, etc.) in the free state or in the form of aroma precursors, we have had confirmation of how M rootstocks, are a decisive driver for achieving quality in the vineyard decisive for obtaining excellent oenological results.”
The change in viticultural perspective that the results of the research carried out by the University of Milan impose in addressing the choice of rootstock is evident. “This discovery leads us to reconsider overall the approach we have always had toward rootstocks,” concluded Marcello Lunelli. The scientific evidence of the importance that Ms play in determining the quality of a wine confirms the need for an accurate choice of the graft combination that takes into account the variety and environmental characteristics but also considered in function of the oenological objective to be pursued.”