Diseases

Question 1

What is Odium known as?

Answer 1

Powdery Mildew
(Uncinula Necator) (fungus)
Thrives in Humid climates, hates rainfall tho.
Likes densely shaded canopies and overcast weather.

dies with Sulfur and Fungicides

Question 2

What is Peronospora?

Answer 2

Downy Mildew
(Plasmopara Viticola - fungus) attacks the green portions of the vines, causing leaves to drop off the vine and limiting photosynthesize.
Arid regions prohibit its growth.

Blue staining BDX mixture - spray of copper sulfate, water and lime made in 1885

Question 3

What is Eutypa Dieback

Answer 3

Dead arm!
(Eutypa Lata - fungus)
Spores carried by rain and infect through pruning wounds. Common in Mediterranean climates. doesn’t affect quality just yields

Question 4

What is Esca?

Answer 4

Black Measles (fungus)
Thrives in warmer climates, no known control or cure. Exacerbated by rainfall and can spread by wine or pruning sheers

Question 5

What is Guignarsia Bidwell Fungus?

Answer 5

Black Rot (Fungus) a black spot on the vines shoots, leaves, and berries. Yield reductions can be disastrous if unchecked.

Question 6

What is Bunch Rot

Answer 6

Caused by a number of Fungi Species. reduces yields and may adversely affect the character of the wine with moldy off flavors. Requires humidity of at least 90%

Question 7

What are the big fungal diseases?

Answer 7

Odium - Powdery Mildew
Peronospora - Downy Mildew
Eutypa Dieback - Dead Arm
Black rot - starts w/black spot
Bunch Rot - lots of fungi species

Question 8

What are the Bacterial Diseases?

Answer 8

Pierce’s Disease
Crown Gall - Black Knot
Bacterial Blight

Question 9

What is Pierces Disease

Answer 9

Bacterial Disease caused by (Xylella Fastidious) transmitted by glassy-winged sharpshooter. A leafhopping insect found near citrus orchards and oleander plants.
Doesn’t let vine produce chlorophyll killing within 1-5 years.
No cure nor chemical control for the disease

Question 10

What is Crown Gall?

Answer 10

Black Knot, Bacterial Diseases.
Agrobacterium Tumefaciens Bacterium
When a vine is affected it develops tumors (galls) on its trunk which strangle the vine. Thrives in colder climates. The disease is spread through the propagation of bacteria-infected budwood

Question 11

What is Bacterial Blight

Answer 11

Bacterial. Caused by Xanthomonas Ampelina Bacterium. Kills young grapevine shoots. Spread by rain and compromised pruning tools, the disease can be controlled by hot water treatments and copper sprays such as the BDX mixture.

Question 12

What are the Viral Diseases

Answer 12

Leafroll Virus
Fanleaf Degeneration

Question 13

What is Leafroll?

Answer 13

A virus. complex of at least 9 different viruses. responsible for 60% of the world’s grape production losses. Leaves curl downward and change color to red and gold. Reduced yields, delayed ripening. Spread through propagation of infected vines or by an insect vector like the Mealy Bug. Currently incurable but it won’t kill the vine.

Question 14

What is Fanleaf Degeneration?

Answer 14

Virus. Nepovirus spread by soil nematodes feeding on infected roots. Deforms shoot growth and leads to poor fruit set and seedless berries. Leaves resemble fans and may form yellow bands around the veins.

Question 15

What is Flavescence Dorée?

Answer 15

A Phytoplasma Disease.
Grapevine Yellows, first appeared in Armagnac in 1949. Leafhoppers and propagation spread the disease, which delays bud break and slows shoot growth. Bunches will eventually fall off the vine. No cure exists. Insecticides may be used to control leafhopper insect

Question 16

What aphid insect is not a disease by a major issue to the vine?

Answer 16

Phylloxera
(Daktulosphaira Vitifoliae)
Aphid that feeds on the roots of vines. Sandy soils act as a natural barrier, impeding the speed of Phylloxera.