A presumably new vine disease that began in the late 20th century Austria and Germany occurred (in 2002 for the first time massively and comprehensively). The name Zweigelt disease (which has unfortunately naturalized in the meantime) resulted from the fact that apparently especially the grape Zweigelt was affected. However, all other varieties have been affected (with slightly different symptoms), so this name is a bit misleading. Sensitive and susceptible to this disease varieties are next to the Zweigelt Blauburger. Green Valtellina. Pinot Noir. Rotgipfler. St. Laurent and Zierfandler,
The first symptoms show up with the veraison (Maturity onset). All of a sudden, the berries go limp, shrink or wither the whole grapes, On grape scaffold are - in contrast to quite similar effect stem necrosis - to see no visible damage. Early detection is more likely with red wine grapes because individual areas of a grape do not completely stain (see above). This partial damage mostly affects the grape tip and is similar to that in South Tyrol, especially in the Vernatsch variety ( Schiava Grossa ) occurring, referred to as "speed camera" form of Stiellähme. Finally, the berries shrink like a raisin, but remain hanging on the green grape structure for a long time. At individual exaggerated discoloration also occurs. This image is similar to the one Esca disease, which causes confusion.
The causes are still unclear bacteria. virus or others microorganisms could not be proven as a reason so far. As causes become phytoplasmas supposed. To date, it is only clear that it is a physiological disorder in the metabolism budget of the vine is. Significant in this disorder seem to be insufficient supply of certain nutrients (the main cause is lack potassium suspected) or imbalance between certain nutrients.
Furthermore, even extreme environmental situations of the vine seem like for example water stress during the growth cycle or to contribute high returns over a longer period of time. However, other circumstances may cause (classic) grapevine, which has nothing to do with the disease described above. These are, for example, the already mentioned Stiellähme, as well as weather-related drought. sunburn and hailstorm, See also a listing of all diseases and pests below Vine enemies,