Vitivulture/Viniculture Flashcards
What is Oidium; how does it affect vines
Powdery Mildew: Fungal Disease
Oidium inhibits bunch development and ripening. If the vine is infected prior to flowering, yields will be reduced.
If the vine is infected after fruit set, berries will struggle to achieve veraison and full size
Rainfall helps to serve as a detriment to the spores
What is Peronospora; how does it affect the vine
Downy Mildew: Fungal Disease
Peronospora attacks the green portions of the plant causing leaves to fall off and limiting the vines ability to photosynthesize.
Arid climate and Bordeaux Mixture (Copper sulfate, water and lime) prevent outbreaks
What is Eutypa Dieback; how does it affect the vine
AKA “Dead Arm”: Fungal Disease
Spores enter the “pruning wounds” of the vine and stunt the growth of shoots. Effected canes may eventually die.
The disease drastically effects yield, but has no effect on the quality of the crop; d’Arenberg uses it as a marketing term for his “Dead Arm Shiraz” ascribing a beneficial effect.
What is Esca; How does it affect a vine
Black Measles: Fungal disease
stunts growth and berry development and may even kill in young vines
In older vines it softens and rots the interior of the trunk causing the vine to rarely live past 30 years
There is no cure that is known and the disease is exacerbated by rainfall and can be spread by wind or contaminated pruning shears
What is Black Rot and how does it affect vines
Fungal Disease
The vine shows black spots on the shoots leaves and berries. Can cause yield reductions if unchecked but can be controlled through fungicide sprays
What is Bunch Rot and how does it affect the vines
Fungal Disease
Grouping of similar diseases caused by a number of fungal species.
Reduces crop yields and can affect the character of the wine by contributing moldy flavors
Botrytis is one type of bunch rot
What is Pierce’s Disease; how does it affect vines
Bacterial Disease
Transmitted by the glassy-winged sharpshooter
Prohibits vines from producing chlorophyll and killing them off within 1-5 years
There is no cure or chemical control
What is Crown Gall; how does it affect vines
Black Knot: Bacterial Disease
Vines affected develop tumors (galls) on the trunk which strangle the vine. During winter freezes the trunk can rupture and rapidly spread the galls to the outside of the plant
What is Bacterial Blight; how does it affect vines
Bacterial Disease
Kills young grapevine shoots
Can be controlled with hot water treatments and Bordeaux Mixture
What is Leafroll Virus; how does it affect vines
Viral disease caused by complex of different viruses
Causes beautiful vibrant colors in the autumn but leads to reduced yields and delayed ripening
What is Fanleaf Degeneration; how does it affect the vines
Viral disease
Deforms shoot growth, leads to poor fruit set and shot (seedless) berries
What is Flavescence Dorée; how does it affect vines
Phytoplasma Disease
Delays budbreak and slows shoot growth causing bunches to drop and grapes to shrivel.
No cure exists, but insecticides can kill bugs transmitting the disease amongst vines
When does budbreak take place
March or April: Early spring
When does flowering take place
6-13 weeks after budbreak
When does veraison normally take place
August
What is the minimum required hours of sunshine to support vinifera
1300 hours
What is the average required rainfall for vinifera
20-30 inches
Which American grapevine species was mostly used for grafting to defend against Phylloxera
Vitis Riparia
What is Albarello
The term for head trained vines in Italy
What is En Vaso
The term for head trained vines in Spain
