Yellowing diseases in viticulture
The yellowing diseases in viticulture is a generic term used to summarize vine diseases caused by pathogens belonging to the phytoplasm group. The yellowing diseases represent a serious threat to viticulture . So far there are hardly any effective control options. The diseases golden yellow ( French : Flavescence dorée ) and the blackwood disease have a major influence on European viticulture . While first-mentioned yellowing disease of the Kleinzikade Scaphoideus titanus ( Scaphoideus Titanus is) is transmitted to be applicable in the black wood disease winch Glasflügelzikade ( Hyalesthes obsoletus ) as a vector .
The yellowing diseases grapevine yellows (distribution area in North America, Italy and Israel ), Australian grapevine yellows ( Australia ) and leaf curl and berry shrivel in the US state of New York were found later (→ viticulture in New York ).
root cause
The phytoplasms (formerly also called mycoplasmas) are bacteria of the class of the Mollicutes . The parasites depend on living host cells, which they find in the phloem of the vine. They use the nutrients (the assimilates) transported there as food and thereby damage the plant's sieve tubes. The formation of phytohormones also causes various symptoms of the disease.
Symptoms and consequences
Infested vines usually sprout normally, at best slightly delayed. Slowed shoot growth up to flowering can also be a first indication. Clear features do not appear until late summer. In dry and warm weather the symptoms appear early, in damp and cool weather the course of the disease is delayed.
The Riesling and Chardonnay grape varieties are hardest hit in the growing areas of Europe. The Sangiovese grape variety is particularly sensitive and usually dies as a result of infection.
Individual evidence
- ↑ Color Atlas Diseases, Pests and Beneficial Insects on Grapevines, page 71
literature
- Jancis Robinson : The Oxford Wine Lexicon . Hallwag, Gräfe and Unzer, Munich 2007, ISBN 978-3-8338-0691-9 .
- Horst Diedrich Mohr (Hrsg.): Color atlas diseases, pests and beneficial insects on the grapevine . Eugen Ulmer, Stuttgart 2005, ISBN 3-8001-4148-5 .
- Pierre Galet : Les maladies et les parasites de la vigne, Volume 1 . Imprimerie du Paysan du Midi, Montpellier 1977, ISBN 2-87777-038-9 .