Esca (viticulture)

The title of this article is ambiguous. Further meanings are listed under ESCA (definition of terms ).

Vine damaged by ESCA.

Leaf symptom caused by an Esca infestation.

It is typical for a Grüner Veltliner vine that is infected by Esca fungi that parts or the entire vine can be affected.

On grape wilted vines, leaf symptoms can look very similar to those of Esca.

When Esca's disease is a complex disease reduction by vineyards has increased rapidly worldwide in the past three decades. It is one of the most dangerous vinewood diseases. The name Esca is derived from Latin and means tinder - an indication of the tinder-like consistency of the wood in the late stage of the disease. It is caused by various wood-decomposing fungi. Since the 1990s, Esca disease has spread increasingly in the northern wine-growing regions. The disease is dangerous because it can lead to the death of the vines.

history

Esca has been known since ancient times (Greeks and Romans). The ancient writers reported on this disease. It has initially spread in the warmer wine-growing regions. It was not until the end of the last century that this disease spread in the more northern wine-growing regions and is already causing infestation rates similar to those in southern regions.

cause

According to the latest research, the cause of the disease is linked to a group of latent fungal pathogens whose way of life is still largely unknown. The investigations showed that the fungal communities of a total of 158 types of fungus are the same in healthy and diseased plants. Fungi known to be putative Esca pathogens were isolated from healthy and diseased plants with similar frequencies and abundances. These findings show that the Esca mushrooms are not real pathogens, but rather specialized species that colonize and break down dead wood.
The most frequently identified fungi in European growing areas that trigger or cause the Esca syndrome are endophytic fungi that colonize tissue cells such as Phaeomoniella chlamydospora (W. Gams, Crous. MJ Wingf. & L. Mugnai), Phaeoacremonium aleophilum (W. Gams , Crous. MJ Wingf. & L. Mugnai) and the wood-destroying white rot fungi Fomitiporia mediterranea (M. Fischer, Basidiomycota), Fomitiporia punctata and Stereum hirsutum . Accompanying (mixed infection) are the fungi Phomopsis viticola , Eutypa lata and Botryosphaeria obtusa . Other Phaeoacremonium mushroom species have also been found in non-European wine-growing regions and Fomitiporia mediterranea is occupied by representative species.

Symptoms

There are two forms of Esca disease with different symptoms.

• In the acute course of the disease, the entire hive suddenly dies, usually in the middle of summer. The leaves hang dry on the vine for a long time and slowly change color from green to brown.
• In the chronic form of the Esca, the sticks often last for several years without dying off completely. The externally visible symptoms are not stable. In some years they are completely absent.

Irregularly distributed, yellowish spots appear between the leaf veins of older leaves, which necrotize from the center. The necroses merge into one another and spread out flat between the leaf veins. The leaf veins remain surrounded by a light green, yellowish zone, the necroses are reddish brown in color ("tiger stripes"). The grapes of the affected vines remain small, the individual berries develop brown, later also black, irregular spots on the berry skin during the summer (black measles). In the initial phase, a rubbery, dark substance often emerges from the cut surfaces of the wood ( gummosis ). Wood tissue infected by the fungus is whitish, spongy, dry and delimited by a narrow, brown to black colored zone. The vines often die within a short time (apoplexy). Leaf and berry symptoms can appear independently.

Esca in production plants

It is mostly caused by mixed infections of Fomitiporia mediterranea , Fomitiporia punctata , Stereum hirsutum and infections with Phomopsis viticola and Eutypa lata . This form of disease affecting older vines is Esca disease itself. It is the final stage of a long process, some of which already begins in the nursery, of successive infections. This most common type of disease usually occurs locally through infection through interfaces and wounds. The more that is cut and the more often perennial wood is injured, the more the occurrence of this disease must be expected. Phaeomoniella chlamydosporum , which is found in young, symptom-free vines,
can also pave the way . It causes Petri disease.

Petri disease (Esca in young vines)

Caused by the fungi Phaeomoniella chlamydosporum and / or Phaeoacremonium aleophilum . In young vines (also in vine seedlings) there are characteristic brownish or blackish discolorations in the wood of the rootstock. The affected areas are often accompanied by dark, rubbery secretions ( gummosis ). The fungi cause vascular pathways to die off in young vines, the vines grow poorly, show leaf necrosis and reduced elongation. As a result, many vines die off. As with Esca, symptoms develop from the start of production. Petri disease is also referred to as a precursor disease (pioneer) of the Esca and should be transmitted through the refinement / grafting.

Black foot disease

Is caused by the fungus Cylindrocarpo destructans . It shows symptoms similar to Petri's disease. Weaker shoot growth, sparse foliage and shortened internodes with chlorotic leaves. Brown to black discolouration forms in the area of ​​the finishing point.

Combat

A direct fight against the disease is not possible. Unfortunately, symptoms often only show up years after infection. This complicates the fight or makes it no longer possible. An important preventive measure is the destruction (burning) of sources of infection in vineyards (diseased vines are carriers of fruiting bodies). Fruit bodies left in place sporulate, especially during the warmer seasons. They cause additional infection pressure. Mark diseased vines during the growing season so that they can be recognized during winter pruning. Timely removal of diseased pole parts with subsequent pole reconstruction (pulling up from below) rarely brings symptom-free poles. Stick overloads should be avoided. Stress (high yields, water stress, etc.) leads to more stick failures due to Esca. One way to protect existing vines from infection is to immediately close cuts and other injuries to perennial wood with a suitable wound treatment agent. Despite the wounds spreading, the underlying tissue dries out - albeit more slowly -, jumps up and as a result disrupts the flow of sap in the ducts. This measure brings only partial success. Root stem damage caused by mechanical cane clearing devices is another possibility of infection and should be avoided whenever possible.

Measures for pruning and training

The pruning should be carried out with as little sores as possible ("gentle pruning") in dry, cool weather and not too early (warm, damp weather favors infection). Basically, one can say that the more cut and the more often the perennial wood is damaged, the more Esca has to be expected.

The “gentle pruning” according to Simonit & Sirch from Friuli / Italy is, after years of testing, another possibility to minimize the infestation of Esca fungi. Marco Simonit and Pierpaolo Sirch have been dealing with the relationship between pruning and the upbringing of the vine and the appearance of Esca since the 1980s. In their experience, the longevity of a vine depends above all on correct pruning that does not damage the vital parts. They observed that vines that had been cultivated for decades after the trestle or head pruning had no or only very few problems with the death of vines by Esca. You have transferred this pattern into the education systems that are common today. In this training system, only annual wood is cut and the short shoot extension is cut so that the flow of sap in the duct tissue is not impaired as much as possible. Cutting back into wood of several years is avoided. Large cuts are not only a place of infection for Esca fungi, they also dry out and disrupt the flow of sap in the older wood.

Planting material

During vegetative propagation, the exact use of hydroxyquinoline sulfate to disinfect the vine wood can prevent the transmission of some fungi. The disinfection of the propagation material is common practice in propagation farms today. Therefore, no propagation material should be cut from visibly infested vines. Studies in Switzerland, however, when comparing the fungal communities of adult vines with young, grafted grafted vines from the same plant material, showed that the Esca mushrooms are not transferred with the grafting . Extensive research is therefore ongoing in the wine-growing countries.

A very decisive criterion for planting material is that the grafting area must be completely overgrown. Inadequate intergrowth of the grafting point is an entry point for Esca mushrooms even in the young plant.

See also

• Eutypiosis

literature

• Horst Diedrich Mohr (Hrsg.): Color atlas diseases, pests and beneficial insects on the grapevine . Eugen Ulmer, Stuttgart 2011, ISBN 978-3-8001-7592-5 .
• Karl Bauer, Ferdinand Regner , Barbara Schildberger: Weinbau , avBuch im Cadmos Verlag, Vienna, 9th edition 2013, ISBN 978-3-7040-2284-4 .
• H. Reisenzein, F. Polesny, E. Höbaus: Diseases, pests and beneficial insects in viticulture . 5th edition. Österreichischer Agrarverlag, Vienna 2008, ISBN 978-3-7040-2319-3 .

Web links

Portal: Wine  - Overview of Wikipedia content on the subject of wine

• Esca Disease of Grapevines, BBA, Oct. 2007, PDF; 1.5 MB ( Memento from December 26, 2011 in the Internet Archive ) (PDF; 1.5 MB)
• Esca Disease , Agriculture Information Center, Information Center
• Evaluation of fungicides to combat ESCA , Barbara Schildberger, Knowledge Report 2010, HBLA and BA Klosterneuburg, S 216-217 (PDF; 105 kB)
• Esca - a disease on the rise? Michael Fischer, State Viticulture Institute Freiburg (PDF; 29 kB)
• Preventing Esca infestation - minimizing infestation - findings from experiments since 1999

Individual evidence

1. ↑ Horst Diedrich Mohr: color atlas diseases, pests and beneficial insects on the vine. 2nd Edition. Verlag Eugen Ulmer, Stuttgart 2011, ISBN 978-3-8001-7592-5 , pp. 144-148.
2. ^ V. Hofstetter, B. Buyck, D. Croll, O. Viret, A. Couloux, P.-H. Dubuis, K. Gindro: Role of Fungi in Esca Disease of the Grapevine. In: Revue suisse de viticulture arboriculture horticulture. 2012; 44, (6), pp. 386–392, archive link ( memento of the original from April 17, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
3. ↑ Horst Diedrich Mohr: color atlas diseases, pests and beneficial insects on the vine. 2nd Edition. 2011, Verlag Eugen Ulmer, Stuttgart, ISBN 978-3-8001-7592-5 , pp. 144-148.
4. ^ Karl Bauer, Ferdinand Regner , Barbara Schildberger: Viticulture. 9th edition. avBook published by Cadmos Verlag, Vienna 2013, ISBN 978-3-7040-2284-4 , p. 375.
5. ↑ named after L. Petri
6. ↑ Francois Halleen, Hans-Josef Schroers, Johannes Z. Groenewald, Pedro W. Crous: Novel species of Cylindrocarpon (Neonectria) and Campylocarpon gen nov.. associated with black foot disease of grapevines (Vitis spp.). In: STUDIESINMYCOLOGY. 2004; 50, pp. 431-455.
7. ↑ Michael Fischer, State Viticulture Institute Freiburg: Stress also promotes the Esca symptoms. In: Badischer Winzer. 10/2007, pp. 15–17 (PDF; 296 kB)
8. ↑ Matthias Petgen, DLR Rheinpfalz: “The gentle way of cutting vines”, Der Winzer, 21st year, No. 12/2015, Österreichischer Agrarverlag, Vienna
9. ^ V. Hofstetter, B. Buyck, D. Croll, O. Viret, A. Couloux, P.-H. Dubuis, K. Gindro: Role of Fungi in Esca Disease of the Grapevine. In: Revue suisse de viticulture arboriculture horticulture. 2012; 44, (6), pp. 386-392. Archive link ( Memento of the original from April 17, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.