Solutions for Esca: the technique of Simonit & Sirch
Prevention is better than cure. As Marco Simonit and Pierpaolo Sirch well know. They have built around the prevention of vine diseases the mission of the Preparatori d’Uva (Master Pruners), who train internal employees of wineries all over the world on the correct pruning techniques to use. But they also know something else very well: that when a plant unfortunately (or due to wrong pruning techniques) becomes diseased, something must be done to save its life before uprooting it. “The heritage of the vinegrower and winemaker,” says Marco Simonit, “lies in their vines, and making vineyards long-lived, or “durable”, as we like to say, must be his, and our, main aim. This is what enables him to obtain in the glass an identity-forming wine that reflects the terroir it comes from.”
The aim of the technique of Simonit & Sirch
The technology of dendrosurgery, developed by the Simonit & Sirch Preparatori d’Uva, aims to save plants from being uprooted by curing one of the most serious vine diseases, Esca – coincidently the most widespread in the world, especially in Europe. It is a complex of pathogens (fungi) that attack the dry wood, corroding it until it becomes spongy, brittle and a yellowish-white colour (called decay). The symptoms of the disease range from the typical “tiger stripe” of the leaves to the dehydration of the berries and the gradual drying up of the plant; within a short time, for the apoplectic forms, or within 4-5 years, for chronic forms, it becomes necessary to uproot and replace the vine with a new, healthy rootling.
The research begins in France
Dendrosurgery is a “surgical” technique experimented firstly in France and then in Italy, which entails the removal of the decay that forms beneath wounds caused by incorrect pruning, the ones through which the fungi penetrate and attack the wood, compromising the integrity of the sap system of the vine. This technique has given really amazing results, leading to 97% of asymptomatic plants operated on in the Schiopetto winery in Capriva del Friuli (Gorizia) in just one year (2015-2016). The percentage has even risen to 99% (also from 2015 to 2016) in France, at Château Reynon, where it all started in 2011 with Denis Dubourdieu. In fact, the first trials began in the winery of the great winemaker who recently passed away. He was the one, five years ago, who called the Simonit & Sirch Grape Preparers to deal with what he considered a pandemic in Bordeaux, which mainly affected varieties such as Cabernet Sauvignon and Sauvignon Blanc.
The dendrosurgery is not new
“In France, in 2001,” recalls Massimo Giudici, head of the Bordeaux branch, “sodium arsenite had left the scene; it was the only chemical treatment that had shown a positive effect in limiting the symptoms of Esca, but was also extremely toxic and had already been banned in Italy since 1977.” Then the consequent fresh outbreak of the disease in the following years and the call from Dubourdieu to look for an immediate and practical solution. “We began studying pruning systems in Bordeaux,” continues Giudici, “and methods for curing and cleaning infected Sauvignon Blanc plants in Sancerre, a particularly sensitive variety to diseases of the wood. Then we carried out bibliographic research and discovered that dendrosurgery is not new, but was described by Ravaz and Lafon as a practice known since ancient times to eliminate wood rotted with Esca, and Poussard used it at the end of the nineteenth century, cutting wood damaged by the action of fungi, with very encouraging results on 90-95% of plants.”
The risks of non-intervention
So the technique devised by the Simonit & Sirch Preparatori d’Uva is not a new one, but rather the recovery of an ancient procedure put into practice with new tools. “With small chains saws,” says Simonit, “we clean the trunk and remove the parts affected by Esca, sometimes leaving only the sides to keep the sap flowing, thus saving the plant, which immediately goes back to producing fruit.” Dendrosurgery has been experimented on 10 thousand plants in six years, a huge number of Sauvignon Blanc, Chardonnay, Cabernet Sauvignon, Cabernet Franc and Pinot Noir vines that have been operated on, grown in six vinegrowing regions: Collio, Isonzo, Franciacorta, Bolgheri, Champagne, Burgundy and Bordeaux. “The earlier you intervene, the better,” Simonit points out. “At the beginning, the technique was also experimented on plants with an apoplectic form, but in this case it didn’t give good results, because the plants eventually reach a state of collapse.”
The study of the Institut des sciences de la vigne
The negative effects of the disease also have significant economic repercussions for the vinegrower. Dubourdieu himself estimated losses at 50 thousand euros per hectare, conducting an analysis on a plot of 10 thousand plants in Médoc with at least 10% of vines infected. According to researchers, this is the cost of replacing them with new rootlings together with the estimated lack of production for at least six years. Not to mention the loss of characteristics for a wine produced by a vineyard with infected plants. In this case, a study by the Institut national de la recherche agronomique and the Institut des sciences de la vigne et du vin of the University of Bordeaux (published in the Australian Journal of Grape and Wine Research in 2012) on wine from Cabernet Sauvignon, has shown that while the impact on phenolic composition is moderate, the one on sensory quality is perceivable with just 5% of infected grapes in the wine.