D1 Viticulture: Anatomy and Growth Cycle Flashcards
In-depth learning of the vine's anatomy and growth cycle.
During what months are vines dormant in the Northern and Southern Hemispheres?
Northern Hemisphere: November - March
Southern Hemisphere: May - September
Below what temperature do vines go dormant?
10ºC (50ºF)
At what temperature does freeze injury/damage occur?
-20ºC (-4ºF)
Temperatures below −___°C (−___°F) will kill most V. vinifera.
−25°C (−13°F)
Vineyards facing west, which get afternoon sun, can experience what issues?
- Vineyard may become too hot, particularly if it’s in a warm climate;
- Grapes face increased risk of sunburn.
- In certain climates, west-facing vineyards tend to endure damper, cooler weather conditions.
What are 3 advantages of sloping vineyards?
- Cold, dense air moves downhill displacing warmer air to higher levels, which produce warm thermal layers on the slope (like the Côte d’Or).
- Soils on slopes tend to be poorer, more coarsely textured and better drained;
- Slopes increase the angle at which solar radiation hits the Earth’s surface, thereby increasing the intensity of heat and light which in turn helps the grapes achieve greater ripeness and concentration.
What are some disadvantages of sloping vineyards?
- Increased risk of erosion;
- Higher costs as it requires hand harvesting.
What are four advantages of vineyards being planted close to a body of water?
The body of water:
- Reflects the sun’s rays;
- Provides source for irrigation;
- Reduces risk of ground frost;
- Can provide morning mists to encourage development of noble rot.
What are the advantages of a vineyard being planted close to a forest?
The trees can act as a windbreak, store heat in cold weather, and reduce erosion.
However, forests can also harbor flocks of birds, which are pests.
Temperature directly affects the yield of a vineyard by influencing:
- Vigor of the vines;
- Number of flower clusters and their size;
- Fruit set.
Temperature directly affects the quality of a vineyard by influencing:
- Yield level;
- Accumulation of sugars and the reduction of acidity in the berry;
- Development of wine aromas.
What is something a winegrower can do in a cool climate to increase the rate of photosynthesis?
Increase the amount of leaf area and canopy to compensate for slowed photosynthesis.
List 5 major soil types.
- Limestone
- Chalk (lower density than limestone, so more free draining)
- Slate
- Granite
- Volcanic
Why aren’t vines often planted as seeds?
Propagation from cuttings is quicker and easier;
- plus, propagation allows for grafting onto phylloxera-resistant rootstock
Vines grown through seeds are not genetically identical to the parent vines and although they can show similar characteristics to their parents, more often they are notably different
What is the most important aspect of winter pruning?
Winter pruning dictates the number and location of buds that will form shoots in the next growing season.
Heavily pruned vines will grow fewer shoots the following summer (and so grow fewer leaves).
What does the term ‘vine vigor’ refer to?
It refers to the general growth of the vine, and a vine’s vigor has ramifications on the yield and ripening of the grapes.
What are three factors that influence a vine’s vigor?
- Available resources for the vine (water, nutrients, temperature);
- The vine’s variety, clone, and rootstock;
- Whether disease lives in the vineyard where the vine is planted, which can lower vigor.
What are three things that can cause excessively low vigor, and what is the solution for each?
- Drought stress –> solved by irrigation (where allowed);
- Low soil fertility –> solved by increased fertilization and drainage;
- Disease –> solved by diagnosis and treatment.
Chlorosis, yellowing of the foliage, is caused by what?
A deficiency of iron, nitrogen, magnesium, and/or sulfur.
Chemical weed control (herbicides) can be organized into three groups:
- Pre-emergence herbicides;
- Contact herbicides;
- Systemic herbicides.
Pre-emergence herbicides:
- Where and when are they best applied?
- How are they absorbed?
- What do they inhibit?
- Best applied to surface soil before weeds grow;
- Absorbed through the roots;
- Inhibit the germination of seedlings.
Contact herbicides:
- To what are they applied?
- What do they destroy?
- Sprayed onto established weeds;
- Destroy the green parts of the weed that are sprayed, resulting in the death of the plant.
Systemic herbicides:
- What are they sprayed onto?
- How are they absorbed?
- What do they destroy?
- Sprayed onto established weeds;
- Absorbed by the leaves and translocate in the sap (move upward and downward in the plant);
- These destroy the whole plant.
How can wind damage be mitigated?
- Artificial Wind Breaks - mobile structures that provide instant protection. Expensive and will need to be replaced;
- Natural Wind Breaks - must be planted before vineyard is planted and established, e.g. trees with dense foliage. Trees can harbor pests and disease, and may need pruning and other maintenance.
For maximum effect the crop should be within 10x the height of the break.
What is lutte raisonée (aka integrated viticulture, or integrated pest management)?
- Synthetic agrochemicals are permitted but only when there is a clear need;
- Vineyards must be constantly monitored for pests and disease;
- Complete list of fertilizers, pesticides, and cultural practices are submitted and grower is inspected at least once per year.
Are biodynamic growers permitted to use Bordeaux mixture and/or sulfur?
Yes, biodynamic growers are permitted to use Bordeaux mixture and/or sulfur.
Bordeaux mixture: 3 kg/ha
Sulfur: 7 kg/ha
Sometimes dynamized ashes of target pests are sprayed onto the foliage in an attempt to control the pest.
What are the main sugars found in grapes?
Glucose and fructose, both metabolized by yeast.
Fructose is found in what kind of grapes?
Late harvested. Fructose is more difficult to ferment.
What happens if you have high concentrations of pectins in your grape juice?
How do you handle it?
Pectins make it difficult to extract and/or clarify grape juice (many aromatic varieties are high in pectins, e.g. Gewürztraminer and Viognier).
Remedy this by adding pectolytic enzymes during grape processing.
What are phenolic compounds?
A group of chemical compounds that affect a wine’s color, texture, astringency and bitterness.
Smaller phenolic molecules (catechins and epicatechins) can taste bitter or waxy, or develop bitter tastes with oxidation.
Are anthocyanins phenolic compounds?
What are anthocyanins responsible for?
Yes, anthocyanins are phenolic compounds.
They are responsible for red wine color, and are found in the skins.
Are tannins phenolic compounds?
What are tannins responsible for?
Yes, tannins are phenolic compounds.
They are responsible for astringency and contribute to the weight and body of the wine.
(They are also antioxidants and preservatives.)
What is the difference between aspect and slope?
Slope is the angle of incline of the terrain.
Aspect is the direction the slope faces (east facing, west facing). Aspect relates to the degree of solar exposure.
Even though grapevines are drought resistant, they still need a minimum of __ mm of rain per year in cool climates and __mm of rain per year in warm climates.
- 500mm in cool climates;
- 750mm in warm climates.
Approximately how many hours of sunlight does a vine require during the growing season?
1300 hours
High soil pH (limestone-rich) contributes to higher ____ in grapes.
Low soil pH (acidic soils) can be a deterrent to viticulture. This can be countered by adding ____ to your soil.
High soil pH (limestone-rich) contributes to higher acidity (low pH) in grapes.
Low soil pH (acidic soils) can be a deterrent to viticulture. This can be countered by adding lime to your soil.
What are the four most important North American vine species?
- Vitis berlandieri;
- Vitis labrusca;
- Vitis riparia;
- Vitis rupestris.
What are the four anatomical structures of the vine?
- Main shoots;
- One-year-old wood;
- Permanent wood;
- Roots.
What are the parts that collectively make up the canopy?
- Stem;
- Buds;
- Leaves;
- Lateral shoots;
- Tendrils;
- Inflorescences/grape bunches.
These are all structures of the main shoots
In the spring, the main shoots of a vine grow from ____ retained from the previous year.
Buds
Compound Buds would also be an appropriate answer
What role does a vine’s stem have in regards to how a vine functions?
- Transports water and solutes to and from the various vine structures;
- Stores carbohydrates.
What are solutes?
In regards to viticulture, they are sugars and minerals – substances that dissolve in liquid to form a solution.
What is the difference between a node and an internode?
Node
- The swelling on the stem where other structures of the vine are attached.
Internode
- the area, or distance, between nodes.
Fun Fact: The distance between nodes is an indicator of the rate of shoot growth, so internode length varies along the cane corresponding to varying growth rates during the season.
What does it mean when shoots lignify?
When green shoots turn brown, and become woody and rigid.
Once this happens, that shoot is now referred to as a cane.
Where do buds form on the vine?
Between the leaf stalk (petiole) and the stem
What are buds made of (read: what do they become)?
Buds become all the green parts of the vine:
- Stem;
- Buds;
- Tendrils;
- Leaves;
- Inflorescences.
What are the two main types of buds?
- Compound buds (also known as latent buds);
- Prompt buds.
What is the main difference between compound buds and prompt buds?
Compound buds form in one growing season and break open in the next growing season;
Prompt buds form and break open in the same growing season.
What do compound buds produce?
Briefly describe what is inside a compound bud.
Compound buds produce the main shoots in the next growing season.
Inside a compound bud there is a primary bud (the main growing point) and smaller secondary and tertiary buds; the latter buds usually only grow if the primary bud has suffered damage (e.g. spring frost).
What do prompt buds produce?
Lateral shoots
On what do prompt buds grow?
They grow on the main shoot which had just grown from a compound bud.
Lateral shoots grow from buds formed in the:
- Current year
- Previous year
Current year (because they grow from Prompt buds)
Compared to main shoots, lateral shoots are:
- smaller and thinner
- larger and thicker
- the same size
Smaller and thinner