🦠 Flavescence dorée

Flavescence dorée, "golden yellowing" in French, is a dangerous disease of the vine. It is caused by a micro-organism, a phytoplasma, which lives in the plant's vessels. The disease is carried by a small insect, a leafhopper. It feeds on the sap of a sick vine and then carries the cause to healthy plants.

The signs show in summer. Leaves on white varieties turn yellow, on red varieties turn red, and their edges curl downward. Shoots do not harden into wood, stay soft and bend. Bunches dry out or drop, and the crop is lost. A sick vine weakens and in time dies.

The plants cannot be cured. So the disease is treated as a quarantine disease in many European countries. Control measures are mandatory: sick vines are pulled out, vines are sprayed against the leafhopper, and planting material is treated with hot water. Growers and authorities watch its spread.

Flavescence dorée belongs among the diseases of the vine. It is harmless to people but very dangerous to vineyards, because it spreads quickly.