Viticulture Flashcards
Botanicals ; What are ‘crosses’ ? Give an exemple.
- Crosses are vines of the same species combined to create a new variety.
- Pinotage is a crossing of Pinot Noir x Cinsault
Technique ; Describe ‘Green Harvest’.
- Dropping or cutting grape bunches off vines before harvest to focus the vine’s energy on fewer, higher quality bunches.
Geography ; What are the classic latitudinal zones of winegrowing ?
- Between 30 – 50 latitudes in North an South hemisphere
Geography ; Name 5 wine region influenced by Rainshadow.
– Alsace
– Piedmont
– Pfalz
– Rioja
– Washington
– South New Zealand
Botanicals ; What is an hybrid ? Give an exemple.
- Hybrids are vines of two or more different species combined to produce a new variety
- Vidal is an hybrid of Ugni Blanc (vinifera) and Rayon d’Or (Seibel)
Measures ; How much is an acre ?
- 43 560 sq. feet
Measures ; How much is an hectare ?
- 2,47 acres
- 10 000 m2
Viticulture ; Speaking of ‘Hens and chicks’ what do we refer to ?
- Millerandage
- Grape clusters with berries that vary in size and number of seeds. Caused by cold weather at flowering, mineral deficiency, or disease. Results in reduced yields and uneven ripening.
How many hours of sunshine a vitis vinifera needs to have fully ripe fruit ?
- 1500 hours, 1800 to 2000 for most quality regions
Which between the cane-pruned or spur-pruned is more often productive ?
- Spur-pruned
Where the Scott Henry trellising system is been invented ?
- Oregon
Why the Chardonnay ‘gingin’ clone is favored in Western Australia (Margaret River) ?
- Gingin clone is prone to leafroll virus and millerandage (hens & chicks) - so it producing lower yields - concentrating flavors overall
Name 2 vine species, other than vitis vinifera.
- Vitis Rupestri
- Vitis Riparia
- Vitis Labrusca
- Vitis Berlandieri
- Vitis Aestivalis
- Vitis Amurensis
What is AXR1 ?
- Hybrid vine that was widely used in the USA as a rootstock to prevent phylloxera. Contrary to what was believed, it was not resistant to the louse and the Californian vineyards were devastated in the 1980s.
The vine grows between .. & 35 Degrees Celsius ?
- 10
- At lower than 10, the vine goes into dormancy and higher than 35, the vine can shut down vegetative and fruit growth, in order to keep water reserves.
What is a degree day ?
- Each degrees over 10 degrees Celsius mark on a given day.
- It is used to classify areas into 5 distinct climates on the Winkler Scale.
- Invented by Albert J. Winkler, from Davis University in 1944, to propose a solution to variety-weather-region decisions challenge. Also called the heat summation method.
- Based on the premise that grape vines do not grow below 10 degrees Celsius. Days during the growing season are multiplied by the mean number of degrees over 10 in a particular month.
- Geographical regions are divided based on the sum of degree days recorded through growing season;
I : 2500 or fewer
II : 2501 - 3000
III : 3001 - 3500
IV : 3501 - 4000
V : over 4000
Explain why Malbec from high altitude vineyards in Argentina have a higher phenolic intensity.
- The altitude directly has an effect on atmospheric pressure. The grapes at high elevation process carbohydrates differently AND benefit from higher solar radiations.
- These two factors increase the concentration of polyphenols in the grapes, as well as abscisic acid (high altitude Malbec tends to taste fresher than expected.)
Define Coulure.
- Occur when a percentage of flowers are not fertilized, then a few berries form.
Define millerandage.
- Some berries develop with no seeds. Some of them grow, but some remain firm and green.
Which one of those is the main effect of Pierce’s disease on the vine ?
a) Discoloration of the leaves
b) Restrict the intakes of nutrient by the roots
c) Delay ripening and diminish yields
- a) Discoloration of the leaves.
- The leaves eventually become dead tissus and the vines generally die within 5 years. There is no cure and it is a bacterial disease that is propagated by insects, mostly glassy-winged sharpshooters.
Which type of mildew does ‘Bouillie Bordelaise’ treat ?
- Downy mildew (mildiou) - (oily yellow spots on leaves - defoliation - shut down)
- Mix of sulfur and copper
- The powdery mildew (oïdium) is treated by sulfur spraying or fungicides. (Fuzzy patches on leaves that can grow on the grapes.)
Which Chardonnay clone is important in California ?
- Wente
Lower / Higher pH means what ?
- Neutral pH = Distilled Water at 7
- Lower pH = Acidity (lemon juice at 2)
- Higher pH = Alkaline (baking soda at 9)
Increased potassium is correlated with a lower or higher pH in the final wine ?
- Higher pH
Benefits of cold soak ?
- Occurs prior to fermentation.
- Red grapes are crushed and kept on their skins at cool temperatures (10-14° C) for days
- Extract color
- Produces less astringent tannins
- Enhances the development of fruit aromatics in the wine
- Improves a wine’s capacity to age
- Renders organic acids more stable
Do Lower Yields Always Produce Higher Quality Wines ?
- Depends
- “Improvement” in quality if the goal is higher alcohol, darker color, riper fruit character, less greenness, less acid, and more concentration.
- If these are not desired attributes, then restricting yields can actually be a negative.
- It is well known, for example, that fruity, high acid wines, like rosés, are much better at higher crop loads.
What clones beteween Dijon and Pommard is popular in California/Oregon ?
- California = Dijon
- Oregon = Pommard
What is preparation 500?
- classic Biodynamic treatment, it involves manure that has spent the winter in cow horns disposed underground on the farms’s land
Biodynamic Prep. 505 ?
Description:Oak barkstuffed inside the skull of a farm animal and stored somewhere moist for the winter.
Use:Reduces soil acidity, wards off disease, and prevents excessive plant growth.
Biodynamic prep. 501 ?
Description:Paste ofsilica(powdered quartz) and water placed inside a cowhorn and buried during summer.
Use:Encourages photosynthesis and ripening.
Application Method:Applied in late spring or early summer, preferably at sunrise and never on young vines. Must be applied after Prep 500.
Biodynamic prep. 508 ?
Description:Horsetail plantboiled into a tea.
Use:Fights fungal infections.
Application Method:Can be combined with fungicide and sprayed on the vine or fermented first and sprayed on the soil during the waxing moon. Must be applied after Preps 500 and 501.
What is this vine desease? Explain
- Powdery Mildew (Oidium)
Thrives in humid climates even without precipitation—rainfall is actually a detriment to the survival of its spores. Powdery mildew affects all green parts of the plant, marking grapes, leaves, and shoots with its dusty white mildew growth.
What is this vine desease? Explain
- Downy Mildew (Mildiou)
Downy Mildew attacks the green portions of the vine, causing leaves to drop off the vine and limiting the vine’s ability to photosynthesize.
What is this vine desease? Explain
- Eutypa Dieback (Eutypiose)
Also called dead arm, the disease is caused by the Eutypa lata fungus. Spores are carried by rain and enter the vine through pruning wounds. Common in Mediterranean climates, the disease is difficult to control as it affects a wide number of plants. Infected vines experience stunted shoot growth as the fungus releases toxins, and eventually an infected cane may die—the dead arm. This disease has a drastic effect on yield, but does not devalue the quality of the crop.
What is this vine desease? Explain
- Esca (Black Measles)
One of the earliest known fungal grapevine diseases, Esca thrives in warmer climates but exists worldwide, and there is no known control or cure. Unlike other fungal diseases, Esca is the result of a complex of fungi, rather than a single organism. On young vines, the disease will weaken growth, affect berry development and discolor leaves; in hot weather an affected young vine may suddenly die. In older vines, the disease affects the wood, causing the interior of the trunk and arms to soften and rot from the inside—a condition that led ancient Romans to use Esca-infected tree trunks for firewood, as its spongy interior quickly caught fire. Mature, Esca-infected vines will rarely live past 30 years of age. The disease is exacerbated by rainfall and can be spread by wind or on the pruning shears of careless vineyard workers.
What is this vine desease? Explain
- Black Rot
Native to North America, Black Rot spread to Europe with the importation of phylloxera-resistant rootstocks in the late 1800s. The disease is caused by the Guignardia bidwelli fungus, originating as a black spot on the vine’s shoots, leaves, and berries. Although yield reductions can be disastrous if unchecked, the disease can be controlled through fungicide sprays.
What is this vine desease? Explain
- Leafroll Virus - considered as a viral disease
Leafroll Virus, a condition caused by a complex of at least nine different viruses, may be responsible for as much as 60% of the world’s grape production losses. Although affected vines display radiant shades of red and gold in the autumn, such beautiful colors, combined with a characteristic downward curling of the leaves, signal the virus’s malevolent side: reduced yields and delayed ripening. Leafroll Virus, spread through propagation of infected vines or by an insect vector like the mealy bug, is currently incurable but it will not kill the vine; thus, infected vines are not always removed.
What is this vine desease? Explain
- Flavescence Dorée, a Phytoplasma Disease
A form of grapevine yellows, Flavescence Dorée first appeared in Armagnac in 1949. Leafhopper insects and propagation of infected vines spread the disease, which will initially delay budbreak and slow shoot growth, eventually causing bunches to fall off the vine and berries to shrivel. The disease will discolor leaves, cause pustules and cracks to form, and may kill young vines. No cure exists, although insecticides may be used to control leafhopper insect populations and retard its spread.
What is Hedging?
- Trimming shoots and leaves that fall outside of the plane of the canopy. It creates a tailored, shrub-like appearance. Hedging keeps the rows clear and prevents damage from vineyard equipment.
What is the purpose of mowing?
- Just after budbreak, rows may be mowed to increase airflow and reduce frost risk. Mowing early in the season encourages regrowth and can be used to soak up excess moisture.
What is the purpose of Tilling?
- Tillage, or cultivation, is the turning over of the top 6 to 10 inches of soil. Tillage can be used to add fertility to the soil through green manure and reduces competition between the vine and groundcover for water and nutrients. It also reduces rodent populations, which can cause significant damage on no-till soils.
What is a Partial rootzone drying?
- A specific deficit irrigation technique where only half of the rootzone receives water at a time, which encourages the vine to be more efficient with its overall water use throughout the season
What is the most common type of irrigation?
- Drip irrigation
It is highly efficient in its water use but expensive to install and maintain. It also provides the ability to fertigate, where fertilizer is added through the irrigation system.
Explain why Phylloxera is so destructive
- Phylloxera feeds on the vine’s roots, and while this is not fatal in itself, the punctures allow infection by pathogens in the soil. Ultimately, this causes necrosis and prevents healthy uptake of water and nutrients. Phylloxera’s damage is slow and can take years to come to fruition, gradually reducing the vine’s ability to successfully ripen fruit and eventually killing it.
What is that?
- Sexual confusion, which has been practiced in French vineyards since 1996, is a natural method of combatting grape worms.
- The idea is to disrupt mating between male and female butterflies by dispersing an artificial pheromone in the vineyards which mimics the natural chemical produced by the females to attract mates.
- Great for leafroll virus
How the vines can be impacted if there’s iron deficiency in the soil?
- Development of Chlorosis
