This worldwide disease of the vine belongs to the group of Yellowing disease because, among other things, the leaves change color in the course of the disease. Young vines are particularly vulnerable in warm wine-growing regions. Are cause phytoplasmas (bacteria-like microorganisms) of type Stolbur (hence Stolbur disease), which by Cicada species when sucking the phloem in Xylem be transmitted. The main transmitter is the glass leaf cicada Hyalesthes obsoletus. Between the end of June and the beginning of August, the adult insects come to the surface where, after mating, the females lay the eggs on the root neck of the host plant. The most common host plants are bindweed, Nettle and dandelion, from which the phytoplasmas can be transmitted from the cicadas to nearby grapevines.
The cicadas only come to the vine by chance, which is why the disease spreads slowly and to a limited extent in viticulture. From the middle of July, the leaves begin to change color, yellow for white wines and red for red wines. The leaves curl down from the edge and take on a metallic sheen. In the case of older leaves, band-shaped discolorations develop along the veins, whereby necrosis can form. The shoots are covered with black pustules on the internodes and turn purple. It is characteristic that the shoots incompletely mature or wood and the immature parts frost discolor black from the top in winter and then die. The name is also derived from this.
If it occurs early, the notes dry up before the blossom, The berries ripen with delay, become bitter and dry out. For years, this can be limited to just a few shoots on a vine, and in rare rare cases, it dies completely. The pathogens (cicadas) are difficult to control because they live underground most of the time. The most effective way is to remove the main host plants near the vineyards. Are particularly vulnerable Blaufränkisch. Chardonnay. Dornfelder. Kerner. Pinot Blanc. Pinot Noir. Riesling and Scheurebe, Are less vulnerable Cabernet Sauvignon. Green Valtellina. Merlot. Schiava Grossa and Riesling, A particular type of yellowing with similar causes and effects is that which occurs again Flavescence doree (Golden yellow yellowing). See also under Vine enemies,