Grapevine yellows

Grapevine yellows is a term used to describe a group of diseases that affect Vitis vinifera, the species of grapevine most commonly used in wine production. These diseases are caused by phytoplasmas, which are small, wall-less bacteria that live in the phloem tissue of plants and are transmitted by insect vectors.

Symptoms

The symptoms of grapevine yellows vary depending on the specific phytoplasma involved, but they generally include yellowing or reddening of the leaves, downward curling of the leaf margins, and stunting of the vine. In some cases, the disease can lead to the death of the vine.

Types of Grapevine Yellows

There are several types of grapevine yellows, each caused by a different phytoplasma. These include:

• Flavescence dorée: This is the most serious type of grapevine yellows. It is caused by a phytoplasma in the 16SrV group and is transmitted by the leafhopper Scaphoideus titanus.

• Bois noir: This type of grapevine yellows is caused by a phytoplasma in the 16SrXII-A group. It is transmitted by several species of leafhoppers in the genus Hyalesthes.

• Vergilbungskrankheit: This is a type of grapevine yellows found in Germany. It is caused by a phytoplasma in the 16SrI-B group and is transmitted by the leafhopper Euscelidius variegatus.

Control

Control of grapevine yellows involves managing the insect vectors and removing infected vines. Insecticides can be used to control the leafhoppers, and infected vines should be removed and destroyed to prevent the spread of the disease.

See also

• Phytoplasma
• Vitis vinifera
• Flavescence dorée
• Bois noir
• Vergilbungskrankheit