This threatening grapevine disease (also known as fall sickness) is caused by various fungi. The most common are Armillaria mellea (Hallimasch or hedge fungus), Roesleria hypogaea and Rosellinia necatrix. The vines show a whitish covering under the bark on the lower parts and the root (mycelial plaques = area of fungal threads). These are particularly common in vineyards with old trees. The vines gradually die or die suddenly, which is known as apoplexy (Greek apoplex = stroke).
Root rot can also be caused or favoured by excessively moist soil (water stress) and animal pests such as phylloxera and root fly larvae, as fungi and other harmful substances such as bacteria can easily penetrate the feeding sites. The fungi are combated by fumigation. In the case of waterlogging, root mould (Dematophora necatrix) can also occur. A specific form is Cylindrocarpon root rot (Cylindrocarpon canker). See also a list under vine enemies.
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