Vine Disease

Question 1

What are the four main categories of vine disease?

Answer 1

Fungal
Viral
Bacterial
Phytoplasma

Question 2

What is fungal disease?

Answer 2

Manifesting as a mildew or mold, it is typically associated with warm or damp climates and attacks the root system or canopy of the grapevines. Spread by wind or rain and can affect an entire vineyard

Question 3

What is a viral disease?

Answer 3

Diseases which spread through grafting or by insects. Can result in shortened lifespan, reduced yields, or change quality of fruit. Usually less destructive than fungal diseases but there is often no known cure

Question 4

What is Phylloxera?

Answer 4

An infestation of an aphid that feeds on the roots of vines

Question 5

Powdery Mildew

Answer 5

A fungal disease which, attacks all green parts of the plant. If affected before flowering will reduce yields and if affected after fruit set will limit veraison.

Question 6

Downy Mildew

Answer 6

A fungal disease which affects green portions of the vine. It causes leaves to drop off limiting the plant’s ability to photosynthesize. Can survive on the bottoms of leaves that fall in the soil and return again in the spring

Question 7

Eutypa Dieback

Answer 7

Dead Arm. A fungus which can affect canes causing them to fall off. Drastically affects yields but not quality. D’Arenberg in Australia ascribes a beneficial quality of the disease on the final product.

Question 8

Esca (Black Measles)

Answer 8

A complex of fungi which can kill young vines and rot the wood of older vines

Question 9

Bunch Rot

Answer 9

A grouping of several different types of similar fungal diseases including Botrytis Cinerea

Question 10

Pierce’s Disease

Answer 10

A bacterial disease most commonly transmitted by the glassy-winged sharpshooter (a leaf-hopping insect). Common in the southern US and Mexico and is being seen further and further northward. There is no known cure or treatment.

Question 11

Crown Gall (Black Knot)

Answer 11

A bacterial disease which forms tumors or galls in the truck of the vine effectively strangling the plant

Question 12

Leafroll Virus

Answer 12

A complex of at least nine different viruses. Responsible for 60% of grape production losses in the world. Leaves turn bright red and cold and curl downward. Results in delayed ripening and reduced yields but does not kill the vine.

Question 13

Fanleaf Degeneration

Answer 13

A virus spread by nematodes in the soil. Deforms shoot growth and leads to shot berries. Affected vineyards must be removed. Leaves spread out like fans and may show yellow bands around the veins.