Experimental cure of Esca in the Loire

Didier Barrouillet in his experimental Sauvignon plotMareuil Sur Cher (Touraine, loire)
I was tipped about this interesting story about vine disease and cure by Laurent Saillard who works in the vineyard of Clos Roche Blanche in the Loire.
Esca is a vine disease which is an increasing nuisance in Europe and in France, the hows & whys being still little understood in spite of extensive studies (read this interesting report on esca - pdf). While known already in ancient times, it surged alarmingly in recent years, especially that a chemical previously used to control it (arsenite) was banned a few years ago. Didier Barrouillet of Clos Roche Blanche, who farms organicly in Mareuil-sur-Cher in the Loire region, has been faced with the problem too, but he noticed that the disease was more prevalent in the plots which had received treatments in the past (before he turned the whole vineyard organic in 1992) than in the plots which had never been touched by chemicals. Some of his vineyards qualify as virgin of any systemic chemical treatment, having been planted on land never cultivated before. What is also interesting is that this disease is even more active in the conventionally-farmed vineyards of his colleagues, where systemic chemicals are still used. Didier Barouillet discovered that the surge of this of disease may lie in the destructive effect of the chemicals accumulated in the ground on the bacterial and microbian life of the subsoil, and that its cure has to do with a pro-active revitalization of the sub-soil of the vineyard. Here is the transcription of an interview I had with him while visiting his vineyards.

Didier Barrouillet showing flowers between the rows To understand how the life diversity is important not only on the surface but in the soil, Didier Barrouillet first tours me around the vineyard of Clos Roche Blanche, surrounded by woods on the slope along the Cher river. He shows me an alley between two rows that he planted with all sort of plants in addition to the weeds which grow freely in his vineyard. He says that his prime idea is to encourage biodiversity to create a balance not only among the insect life, but also among the mycetes, the fungus in the soil. He added the active search for diversity to his already organic farming 10 years ago after reading a study about how plants defend themselves against insects. It was thought before that plants would produce naturally insecticides but studies showed that the plant acted indirectly, by producing pheromones and thus attracting insects-allies which would combat the pests.The dirt road across Clos-Roche-Blanche vineyardsWalking in the vineyard, he points to a semi-natural field connecting to this alley further down on the slope, which is home to many wild weeds, flowers and a few plants that he brought there. He lets this surface as is, so that diverse insects can prosper. The alley between the rows, also covered with weeds and selected plants, plays the role of a corridor where these diverse insects can come deep into the vineyard. Using auxiliary insects to combat pests without using chemicals is at the core of organic farming and the mixing of fallow land and woods with the vineyard is very important. The plants that he added in this incursive alley are all honey-plants ones. He points to a santoline which is particularly interesting in this regard. Many of the many smaller plants that he brought attract hymenopters that feed off pests by eating their larvae. He shows me a small fly, a syrph fly, a polyphagus insect that helps a lot combat pests. The fallow alley is pretty crowded by insects. He cuts the grass in the fallow field only once a year so that year around the insects are at home there. In the vineyard itself he leaves also diverse plants grow, he shows me several wild plants that came by themselves, some gaillet here, some linaire there, also centaurées, wild carrots, milleperthuis (St John's wort), bourrache even vegetables here and there. If these plants bring a diverse insect life on the surface, they have also little-known very positive consequences on the sub-soil life : each of these plants has different root exudates, each of them having different benefits for the microbian life of the soil. Some exudates have nematicid properties (kill nematods), other kill insects, some target fungus, some others like sarrasin even block the germination of certain weeds around them. When he occasionally passes with the tractor, he doesn't make any décavaillonage so as to preserve the underground life close to the surface, he just slices beneath the surface but doesn't overturn the sliced earth like it is done with décavaillonage.Showing a cured vine with its leek-saviourThe esca disease : the Sauvignon as a grape variety is particularly affected by this disease, which increased dramatically in the last few years in France. There are other varieties that are less exposed to esca for some reason, like Chardonnay. The symptoms are that the vine seems to dry out and die very rapidly, with foliage shrinking in volume and showing signs of decay on the leaves.. Didier Barrouillet notices that his plots that have always been organic (vines planted on virgin land where no agriculture was ever conducted before) are virtually free of the disease. These now-nearly-20-year-old vineyards are free from Esca. This particular vineyard is located near a Gamay block about which I made a tractor story a few months ago, it lies right along the woods on the Cher-valley side. In the plots which in the past were treated with systemic chemical products (fungus-killers, weedkillers including Monsanto's Roundup) before he implemented organic farming, he has some bouts of Esca, even if much less than in colleagues's vineyards which are still heavily treated. He thinks now that the sudden surge these recent years of Esca has to do with the wide use of Monsanto's Roundup in the vineyards. [Monsanto is an agrochemical company which yields half of its revenue from its flagship weedkiller, Roundup. Glyphosate, its main component, has been associated with sudden crop death and scientists have established that its destructive impact on the subsoil life brought the emergence of toxic fungus that were previously held in check by other subsoil microbes].
According to Didier barrouillet, there is a direct relation between the mycorhization rate of the plant roots and Esca. The higher the mycorhization rate in a given vineyard, the lower will be the incidence of esca among its vines. Mycorhization is the fungus activity on the roots of the plants. All the plants need this exchange with fungus at the root level and attract a crowd of these mycetes. All plants, except cruciferous plants like cabbage for example. the mycorhizes along the roots are particularly useful for the plants when there is a lack of phosphorus in the soil because these fungus are the ones who bring phosphorus to the plant in exchange with carbon-hydrats that they are unable to produce by lack of chlorophyll. There is an active, mutually-beneficial relation between the plants and the mycorhizes, the mycetes living along the roots. To confirm his intuition, he made a study from roots taken from a conventionally-farmed vineyard elsewhere (which had a lot of dead vines with esca), using fuchsin baths and found a mycorhization rate of zero. In another plot where esca was less widespread (say, with a pathology proportion like it used to be 25 years ago), the mycorization rate of the roots was 25%. It seemed to show an obvious link between the systemic chemical products, the mycetes density on the roots, and the extent of esca. Asked if he shared his research with someone in the French agro-research bodies (INRA for example), he answers that they're not interested in the origin of the Esca surge and consider him as a lunatic. They eventually look for a cure but don't want to investigate on the root (appropriate term !) of the problem. It's been proved by an INRA study made at least 10 years ago that systemic chemicals are channelled down by the sap and destroy the mycetes along the roots like antibiotics do in the digestive tracks of humans. Now, it's easy to destroy this microbian population, but harder to restore. A damaged soil, he says, needs a lot of time to recover from the chemicals, sometimes a century could be necessary to get rid of the long-life remnants of years of chemical sprayings. This is especially true for the vineyards : in France, lots of copper has been dumped, first, in the early 20th century, the farmers doing their copper mix (bouillie bordelaise) themselves and weren't shy of spraying high doses. A well-managed vineyard, he says had to have blue posts, this proved a generous use of copper... Copper actually doesn't harm mycorhizes but it does cause trouble in other subsoil organisms. But later, more harmful products were sprayed with the same blind generosity, the growers unknowingly destroying their soils year after year.
What made him go through his experiment with bringing mycorhizes with wild leeks was his encounter with a very knowledgeable person in the field, Mr Mario Fregoni, a very old man now, who is a former president of the Office International de la Vigne et du Vin, who told him that the experiment could work. He didn't say that to be kind but really thought it feasible. Mr Fregoni added that it was not possible to just spray exogen mycorhizes in the vineyard because they die after 2 years, as they don't survive the fierce competition with other microbes in the soil.The virgin (soil never treated) Gamay plotNow, some plants have a mycorhization rate much higher than other plants, that's the case for the plants of the Allium family (which includes leeks, garlic, shallots) : it's as if these plants needed to have 100% of their roots colonized by mycorhizes. Plants can indeed attract and appeal microbes and fungus when they need them, and leeks and other allium plants do it very well.
At this point of the conversation, we arrive in a vineyard plot where he says he has been conducting for 2 years experiments with leeks. He decided to voluntarily re-mycorhize the under-soil of this Sauvignon plot by planting leeks. The interesting thing is that these mycorhizes or mycetes are able to migrate from a root to another : from the leeks' root hair, they can move to the vine's root nearby, and according to him even migrate a few meters from their original home, weaving a mycelian web under the surface. So he planted wild leeks (also called perpetual leeks) along with garden leeks in this plot. He planted in priority near the esca-stricken vines, when the symptoms on the shrinking foliage announce the near-to-come death of the vine. Miracles did happen since he started this experiment, and he saw vines recovering from esca, which he never saw before. He shows one of these vines with a foliage free of symptoms and expanding. He shows another vine that he thought was already dead last year, he had even prepared a marcotage from the next vine to replace it. But the leek planted along it resuscitated it back to life. It still needs time to recover complete normality but is already in good way.A rapidly-recovering vine (initially almost dead) with its leek-saviour and its purple flowerWalking further, he shows other esca-suffering vines which show advanced signs of recovery. Even if this experimental Sauvignon plot makes only half an hectare, he needs quite a lot of leeks, and he just plants one here and there, in priority near the sick vines. But a single leek near an imperilled vine makes a difference because of the high density of mycetes on their root hair. He planted wild leeks randomly all over the plot (about one every 3 or 4 vines) but you dont always spot them because the grass is occasionally cut and the leeks along, but these leeks are still alive and active in the undersoil, with their root hair busy sipping the earth's nutrients.Cured Sauvignon-vine photo-op for Joe Dressner Wild leeks are particularly difficult to find for a mass planting (they don't sell them in nurseries) but they are stronger and multiply naturally through the bulbs year after year. To find them, he had to go in the Languedoc, in Minervois, where they are very widespread. With the help of friends-vignerons there, he picked a stock of perpetual leeks in the wild to replant here in the Loire. For the story, his friends in Minervois testified that in the vineyards thick with wild leeks, they didn't have any esca (esca is also present in the languedoc and is sometimes called Apoplexie). This experiment is interesting because it offers a glimpse of hope, particularly for organicly-farmed estates which still face esca casualties in the vineyard. This particular plot is organicly farmed for 18 years now, but previous treatments still take their toll on the subsoil life, as Didier considers that there's a direct link between Monsanto's Roundup for example and the depletement of mycorhize activity on the vine roots.A machine left by Pascal Potaire last year is taking root...We were leaving the vineyards and preparing to cross the woods back to the house/winery on the other side. We stopped a minute near this mammoth-machine abandonned last year along the vineyard by Pascal Potaire, a friend of Didier and Catherine. Old machines are nearly human, it looked patheticly quiet in the high grass. The keys were still in place, but it needs a battery recharge now for sure, the battery is in full view and exposed to the rain. We tried to ignite the engine, but the starter offered no reaction...Minutes later, as we approached the dirt road through the wood, we heard (but couldn't see) a roe deer running away. The electric fence is not plugged in yet and that one was scouting this place known for its tasty grapes...Light-years from there...Now, look at that : this picture wasn't shot in the high times of the agrochemicals (in the 70s' or the 80s'), but in 2009 (in march or april) somewhere in the Loire. No worry, this is at a comfortable distance from Clos Roche Blanche, at a double-digit number of kilometers from there...But what do these vignerons think they are doing here ? Where is the legendary farmer's common sense gone ? Just imagine the devastation and the agony of the subsoil living organisms in this plot. This drown-into-weedkillers soil is victim of the obsessive search by conventional growers for a square-looking vineyard, and they probably do that because the father or grand-father did that in the 1970s' and nobody ever put this madness into question....
I remember reading a nice post with pictures on the subject by Jim's Loire shortly after having shot this picture, I wondered if telepathy was involved here...
............P.S. the picture of these happy vintners of the Loire behind the resurrecting vine is not mine. You can also see it on Joe Dressner's captaintumorman.com on his may 21st 2009 post (click on "older posts".

Comments

[aynard]

Thank you for this so interesting report. I am very exited by this... We suffer a lot of the esca and I am going to visit Didier.
Thank you again.
Aynard

[Iris]

Hm, I'm not quite convinced by the theory, as even in my naturally cultivated "young" vineyard (20 years now), where the soil had never seen herbicides and pesticides and analyzed by Claude Bourguignon as provided with an excellent microbiological life, I've noticed "apoplexy" here and there during the last years - and as the whole plot is run with a natural herbs cover (with most of the varieties you cited plus others - even wild leeks and garlics and only cut once a year, like in your example), there must be some other factors - but it would be interesting, to know some further research...

[Jim Budd]

Another excellent and fascinating post Bertrand. I have talked to Didier and like you think that this may well be a way forward to combat Esca – incidentally also less prevalent in Menu Pineau, although the plantings of Menu are small compared to Sauvignon Blanc. Typical that the INRA consider Didier to be a lunatic.

Also worth noting that Didier doesn't disturb the soil's profile but turning over the soil. Claude Papin in Anjou is very much opposed to the cultivation of the soil and I have discussed with Aynard and his wife Isabelle that Claude Bourguignon has similar concerns about the need to maintain a soil's delicate profile.

[Kevin McK]

Bert,

I can't thank you enough for researching and writing this great post. I have been wanting to write about this for a year, but have been buried with other work. Whats more, your post is probably better written than I could hope mine to be. I will link this page from our front page.

Having worked with Didier for some 15 years now, there is no doubt that he is a natural genius for this sort of historical research and application of theory. I am thrilled that the positive results are evident.

Bravo,
Kevin

[M. Messenie]

Great report! I think people who found this fascinating would appreciate the work of mycologist Paul Stamets.

[Mark]

Very interesting stuff there. With the internet it is nice to be able to share info about what is happening in the industry across borders and languages.

I appreciate the information.

[zitoun]

Very very interesting... I'm working on this ESCA issue as agronomist engineer in a famous nursery and I try to be aware since the last 6 months about all which talk about vines trunk desease.

This experimental conclusions are very interesting because we try to show that it's soil which is important. Why INRA fellow didn't want to know nothing about this work, it's only because this hypothesis is too far for them to the problematic (trunk, wood disease). They are very narrow-minded as we all know but it doesn't matter.

What I could understand by this post, it's the real fact that we all have to understand that the plant need to equilibrate herself to be able to struggle against all attack. When we started to used chemical products a couple of decades ago, it was in a nice intention to protect our crops and preserved our yield to give food for everybody, but we have forgotten the most important concept in nature. Keep natural balance. Keep you environment well balanced if you want a crop well balanced. mycorhized root are one of the best symbol. It's the perfect argument for me to convince all people to switch to biological or at least less chemical thinking. The fungi cycle in the soil an all the interactions... that is the key. The indirect reason to the ESCA resistance. Mycorhize and well balanced soil help the plant to be more thick, more strong, more prepared to any stress. I'm sure we could verified that this sauvignon and Gamay vineyard are much more resistant to every other pathogen that the other viticulturist have to manage as well.

After, I'm impress about the discovery of the specific effect of wild leek or garlic plant to control ESCA... I really should meet this viticulturist. This true vigneron.

[Mart van Weert]

Thanks Bertrand. As always great story. I like to read these more technical posts they give a nice insight in the thinking of some vignerons. Clos Roche Blanche is a favorite of mine. Unfortunately not available here in Italy.
Are you by the way planning to do a post on italian natural wines? There are some interesting things going on here but the scene is no as alive as in France.

[Bertrand]

Hi Mart,
No I haven't immediate plans to go to Italy, but I know there is also a vibrant scene of artisan vignerons making beautiful additives-free wines. I tasted a few of them and would like to visit one day.

[Fabien Laine]

Vey nice article and very instructive ! Thanks a lot for sharing !

Also is there any email address to contact Didier ? Cannot find any website for their domain !