Viticulture Flashcards
Roughly how many cultivars are in commercial production?
1400
How do feeder roots and permanent roots differ?
Feeder roots grow new each year and reach very deep in the soil
Permanent roots only go down the first few feet of topsoil
What is a scion?
The above ground portion of the vine that has been grafted onto rootstock
What is more fruitful: dormant buds on one year old wood or dormant buds on old wood?
One yar old wood - older turn into “Suckers”
On average, how many clusters are there per shoot?
1-3
What are “infloresences”?
Flower clusters only found on fruitful shoots
How can a vines vigor be quantified?
By pruning and weighing the amount that was pruned
What factors can impact the vigor of a vine?
Site selection
Rootstock
Choice of trellising system
Pruning
Irrigation or lack thereof
What is the difference between a crossing and a hybrid?
A crossing are two cultivars of the same species being interbred
A hybrid is two different species within the same genus (vitis) being interbred
What is a clone?
A variant within a grape variety that shows some different characteristic than the original
Generally speaking, which is more productive: a pure vinifera vine or a hybrid vine?
Hybrid
Is Vitis Riparia drought tolerant?
No - in the wild grows on banks of rivers/creeks and up trees - Riparian areas
What species does St. George belong to?
Vitis Rupestris
Where is Vitis Berlandieri native to?
Texas
Macroclimate is defined as:
What affects these areas
Larger region (Think all of Tuscany)
Mountain ranges, Massifs of France, etc.
Mesoclimate is defined as:
What affects these regions?
Smaller area than macro climate - can be single vineyard all the way up to a region (think of Brunello di Montalcino vs. Vino Nobile)
Rivers, lakes, topography, soils, etc.
Microclimate is defined as:
What affects this area?
Area right around the vine or the fruit itself
Vine training, canopy management, distance of fruit to soil, etc.
What are the four major climate classifications?
Mediterranean
Continental
Maritime
Subtropical
What is transpiration?
Vines “Sweating” to regulate temperature - opens or closes stomates
Would a vine rather die from starvation or dehydration?
Starvation (stopping photosynthesis)
Where is the Winkler Index used?
The United States and not much elsewhere
Where is the Huglin Index used?
Outside the US - Europe especially
Does the Winkler Index account of day length?
No - this is a major drawback
Only accounts for heat accumulation
What does the Huglin Index account for that the Winkler Index doesnt?
Latitude
How many leaves are generally needed to ripen one cluster of grapes?
Between 12-16
Are shaded buds more or less fruitful than those with sunlight?
Less fruitful
Are shaded shoots (for following vintage) more or less fruitful than those with sunlight?
Less fruitful
Do shaded berries ripen slower or faster than those with direct sun exposure?
Slower but direct exposure can also increase microclimate temperature which can interrupt ripening too
Are acid degradation and tannin ripeness more closely related to temperature or light exposure?
Temperature
Phenolic compounds are produced in light or shaded conditions?
Light - helps break down pyrazines
What is the minimum amount of sunshine hours needed for a vine to ripen?
1250
Generally speaking, when is water desired throughout the growing season?
Early prior to verasion
Generally, is late season rainfall good or bad?
Bad - especially around harvest time
- Yields more diluted wine due to grape swelling
- Excessive swelling can split grapes and invite disease into the vineyard
In windy conditions, do vines require more or less water?
More - severe wind can cause vines to close stomates
Reduces moisture in the vineyard
Are vines more or less vigorous in windy conditions?
Less
What are two ways in which vines can be protected from harsh winds?
Vine shelters/windbreaks (Lanzarote)
Planting parallel to the wind w/ low training (Provence, Rhone)
What is the rough formula for temperature change as altitude increases?
For every 300 feet (100m) in elevation - temperature drops 1 degree fahrenheit
How much more sunlight do vines get per 100 feet in elevation?
2% more sunlight exposure due to thinning atmosphere
In a maritime climate, are diurnal shifts more pronounced above or below the inversion layer?
Below
In the Southern hemisphere, which aspect gets the most amount of sunlight? Vineyards facing North, South, East, or West?
North
