VITICULTURE 🚜 Flashcards
Vine species
- Vitis Vinifera.
- American vines (Vitis Labrusca, Vitis Riparia, Vitis Rupestris, Vitis Berlandieri).
Main parts of the vine structure
Main shoots, one-year-old-wood, permanent wood and roots.
Major structures of the main shoots
Stem, buds, lateral shoots, tendrils, leaves, inflorescences/bunches.
Stem - what it is, functions
Structure to which all the other structures are attached. It transports water and solutes and it’s a store of carbohydrates.
Buds - what they are, functions
They contain all the structures in miniature (stem, buds, tendrils, leaves, and often inflorescences).
Two types:
- compound buds for main shoots (next growing season);
- prompt buds for lateral shoots (same growing season).
Compound buds
They form in one growing season and break open in the next growing season, producing the main shoots.
Prompt buds
They form and break open in the same growing season, producing lateral shoots.
Lateral shoots - what they are, functions
Smaller and thinner than the main shoots, they have a stem, leaves, buds, tendrils and sometimes inflorescences. Their main function is to allow the plant to carry on growing if the tip of the main shoot has been damaged or eaten; additional source of leaves for photosynthesis. They often produce inflorescences (second crop, it’s common on Pinot Noir) but different ripening, so green harvesting to improve the ripeness uniformity. No good near the base of the main shoot, because of shade on the fruits and no airflow.
Tendrils - what they are, functions
They support the shoots.
Leaves - what they are, functions
The main site of photosynthesis (sugars produced are used for vine growth and metabolism), used also for transpiration.
Inflorescences - what they are, functions
Between 1 and 3 clusters of flowers on each main shoot which becomes a bunch of grapes.
Bunches
Fertilised inflorescence, not all the flowers in inflorescence become grapes.
Photosynthesis
The process by which green plants use sunlight to produce sugars (used for vine growth and metabolism) from carbon dioxide and water.
The leaves are the main site of photosynthesis in the vine.
The maximum rate at temperatures between 18° and 33°C and at sunlight levels that are above on third of full sunshine.
Transpiration
Water and nutrients are brought from the roots to the underside stomata of the leaves, which are transformed as vapour; stomata are partially closed if the vine is water-stressed, this limits photosynthesis by preventing carbon dioxide. Sugar accumulation is correlated with transpiration.
Typical number of inflorescences per main shoots
Between 1 and 3.
Parts of the grape (berry)
Pulp, skin, seeds.
Components of pulp
Water, sugars, acids, some aroma compounds and some aroma precursors. The majority of the grape’s weight and usually it’s colourless.
Components of skin
High concentration of aroma compounds and aroma precursors, tannins, colour compounds.
Components of seeds
Oils, tannins, embryo.
Bloom
A powdery waxy coating that covers the surface of the grape.
Component of stem
Tannins.
One-year-old wood - what it is, functions
The main shoots from the last growing season that were kept at pruning, depending on the pruning and training decisions. It supports the compound buds.
Permanent wood - what it is, functions
Trunk and woody parts that are older than one year, depending on the pruning and training decisions. It transports water and solutes, and stores carbohydrates and nutrients.
Roots
In the top 50 cm of the soil and also over 6 m down, they anchor the vine and uptake of water and nutrients, store of carbohydrates and produce hormones for vine growth and grape ripening. Usually, vines are grafted onto a rootstock.
Length of roots penetration
Usually 50 cm, but also over 6 m.
Canopy
Main shoots and all their major structures (stem, buds, leaves, tendrils, lateral shoots, inflorescences/grape bunches).
Solutes - what they are, examples
Substances that dissolve in a liquid to form a solution.
Sugars and minerals.
Ways of vine propagation
Cutting, layering, seeds.
Cutting - what it is, pros/cons
The most common way for vine propagation. A section of vine shoot is planted and grows a new plant. It permits the use of rootstocks. Usually genetically identical to the parent plant. Nurseries are able to treat vine cuttings to avoid the spread of diseases. Risk of random mutations.
Layering - what it is, pros/cons
A way for vine propagation. A cane is bent down and a section of it is buried in the ground, the tip of the cane points up out of the ground, the cane link is cut when roots are established. Used to fill gaps in the vineyard. No use of rootstocks (no protection against phylloxera). Usually genetically identical to the parent plant. Risk of random mutations.
Clonal selection - what it is, pros/cons
Recent practice (last 40-50 years), propagation of a single vine with particularly favourable characteristics by cuttings. Usually buying young vines from a nursery (no virus infection, limited number of clones). Grape grower plants different clones of the same variety (uniformity, simple management but less complexity and balance if only one clone).
Mass selection - what it is, pros/cons
Propagation process by taking cuttings from several different vines in own vineyards and cultivate these cuttings, selection of the best-performing vines.
✅ Diversity of planting material, use of own unique planting material.
❌ Cost (time and labour), increment of eventual diseases.
Clone
The reproduction of a single variety by cutting or layering, with genetically identical characteristics to the parent vine.
Cross fertilisation
The pollen from the stamens of the flowers of one vine is transferred to the stigmas of the flowers of another vine and fertilisation occurs. Grapes develop and seeds from these plants are planted and grown, so a new grape variety is created with different characteristics from the parents. It happens to create an offspring with the favourable characteristics of the two parent vines, but not always happens (Müller-Thurgau, high yields of Madeleine Royale but not the same quality potential of Riesling).
Hybrid
A new vine whose parents come from two different species. For example, Vidal = Ugni Blanc (V. Vinifera) x Rayon d’Or (Seibel family). Combine the resistance of non-vinifera species and the quality of fruit from Vitis Vinifera (not always it happens).
Cross
The offspring that comes from two parent vines of the same species (Pinotage = Pinot Noir x Cinsault).
Vidal is the hybrid of…
Ugni Blanc x Rayon d’Or
Pinotage is the cross of…
Pinot Noir x Cinsault
Müller Thurgau is the cross of…
Riesling x Madeleine Royale
Difference between Pinot Noir Clone 115 and 521
115: High-quality red wine production, low yields of small grapes.
521: Sparkling wine production, high yields of big grapes.
Head grafting - what it is, pros/cons
Also called top grafting, when the vine grower cuts the original vine at the trunk and grafts a bud from new vine variety on top.
✅ Faster production.
❌ Rootstock could be not equally suited for the grape variety.
Main phases of the vine growth cycle
- Dormancy
- Budburst
- Shoot and leaf growth
- Flowering and fruit set
- Grape development (grape berry formation, véraison, ripening, extra ripening)
- Harvest
Respiration
The process in which energy is released from food substances (sugar). Slower at cool temperatures than warm ones.
Coulure
Fruit set has failed for a high proportion of flowers (when ovule fertilisation is unsuccessful). It’s caused by an imbalance of carbohydrate levels (low rates of photosynthesis due to cold, cloudy or hot conditions, vigorous shoot growth due to very fertile soils or fertilisers). Some grape varieties are more susceptible than others (Merlot, Cabernet Sauvignon).
Millerandage
High proportion of seedless grapes, reduction of the yield, grapes stay small, green, and unripe. It’s caused by cold, wet, windy weather at pollination and fruit set.
Xylem
Type of transport tissue that transfers water and some nutrients from the roots to other parts of the vine.
Phloem
Type of transport tissue that transfers sugars from the leaves to other parts of the vine.
Requirements for the vine growth cycle
Heat, sun, water, nutrients, carbon dioxide.
Terpenes
Aroma compounds which give floral and citrus aromas such as the grapey aromas found in Muscat.
Stages for the grape development phase
- Grape berry formation
- Véraison
- Ripening
- Extra-Ripening
Period of the dormancy phase
November – March
Period of the budburst phase
March – April
Period of the shoot and leaf growth phase
March – July
Period of the flowering and fruit set phase
May – June
Period of the grape development phase
June – October
Period of the harvest phase
August – October
Requirements for the dormancy phase
Temperatures below 10°C.
Requirements for the budburst phase
Avg air and soil temperatures above 10°C.
Requirements for the shoot and leaf growth phase
Stored carbohydrates, heat, sun, water and nutrients.
Temperature range of 18-33°C.
Requirements for the flowering and fruit set phase
Warm temperatures (above 17°C for flowering and 26-32° C for fruit set). Heat, sun, water and nutrients for bud fruitfulness in the next growing season.
Requirements for the grape development phase
Heat, sun, mild water stress (smaller grapes with thick skin).
Hazards for the dormancy phase
Extremely cold temperatures (-15/-25°C). Unusually mild temperatures.
Hazards for the budburst phase
Frost. Cold soils.
Hazards for the shoot and leaf growth phase
Low carbohydrates level, water stress (limits photosynthesis and shoot growth).
Hazards for the flowering and fruit set phase
Rain, cloud, wind, cold temperatures.
Hazards for the grape development phase
Too much water and nutrients (can prolong grape berry formation), excessive shading of grapes. Very cold or very hot conditions throughout the day and night.
What happens during the dormancy phase
Vine supports its growth by using stores of carbohydrates (previous year). Winter pruning.
What happens during the budburst phase
Buds swell and open, green shoots start to emerge. The timing of budburst depends on several factors: air temperature, soil temperature, grape variety, human factors. Continental climate better than maritime (marked difference in temperature, so budburst more uniform). Dry and free-draining soils (sand) tend to warm up quickly than water-storing soils (clay). Grape varieties have different time of budding (early for Chardonnay and Pinot Noir, late for Sauvignon Blanc and Syrah). Also human factors to modify the time of budburst (late winter pruning).
What happens during the shoot and leaf growth phase
Shoots continue to grow, leaves and inflorescences mature. The fastest rate of growth is between budburst and flowering.
What happens during the flowering and fruit set phase
Flowering is the opening of the individual flowers within an inflorescence. Fruit set (from 0 to 60%, typically 30%) happens when flowers become grapes.
What happens during the grape development phase
- Grape berry formation
Hard green grapes start to grow in size. Accumulation of tartaric and malic acids, some aroma compounds and aroma precursors start to develop (motoxypyrazines), tannins (bitter), low sugars. High water flow into the grape by the xylem. - Véraison
Grape cell walls become stretchy and supple. Synthesis of anthocyanins, then change colour for red grape varieties. High levels of tannins for black grapes. - Ripening
Accumulation of water and sugar, development of tannins, colour and aromas. Acid fall (tartaric acid doesn’t change but it will be diluted with sugar and water, malic acid is used in respiration). Slow water flow via xylem, transport of sugar solution by phloem (correlated to the rate of grape transpiration). Methoxypyrazines levels fall (attention for cool temperatures and limited sunlight), other aroma compounds and precursors increase (terpenes). Tannins levels decrease slightly (polymerisation so tannins become less bitter). Anthocyanins increase (most rapidly with sunlight and temperatures of 15-25°C). - Extra-Ripening
Grapes start to shrivel, loss of water then sugars concentration (no transport via phloem). Extra-ripe aromas can develop. The capacity to leave grapes on the vine also depends on weather conditions and disease pressure.
Factors that influence the length of the ripening
- Grape variety (Chardonnay and Pinot Noir are early-ripening, Cabernet Sauvignon and Grenache are late-ripening).
- Climatic conditions (high sugar-accumulation in a hot climate).
- Management of the vine and vineyard (shade of the canopy can slow down ripening).
- Time of harvest (human factors and natural factors).
The optimum temperature range for photosynthesis
18°-33°C
The optimum temperature range for anthocyanin synthesis
15-25°C
What happens during the grape berry formation stage
Hard green grapes start to grow in size. Accumulation of tartaric and malic acids, some aroma compounds and aroma precursors start to develop (motoxypyrazines), tannins (bitter), low sugars. High water flow into the grape by the xylem.
What happens during the véraison stage
Grape cell walls become stretchy and supple. Synthesis of anthocyanins, then change colour for red grape varieties. High levels of tannins for black grapes.
What happens during the ripening stage
Accumulation of water and sugar, development of tannins, colour and aromas. Acid fall (tartaric acid doesn’t change but it will be diluted with sugar and water, malic acid is used in respiration). Slow water flow via xylem, transport of sugar solution by phloem (correlated to the rate of grape transpiration). Methoxypyrazines levels fall (attention for cool temperatures and limited sunlight), other aroma compounds and precursors increase (terpenes). Tannins levels decrease slightly (polymerisation so tannins become less bitter). Anthocyanins increase (most rapidly with sunlight and temperatures of 15-25°C).
What happens during the extra-ripening stage
Grapes start to shrivel, loss of water then sugars concentration (no transport via phloem). Extra-ripe aromas can develop. The capacity to leave grapes on the vine also depends on weather conditions and disease pressure.
Ideal latitude for vine growing
Between 30° and 50° on each side of the Equator.
Differences for daylight hours about latitude
Low latitudes have similar daylight hours throughout all seasons. High latitudes have longer daylight hours in the summer and shorter daylight hours in the winter.
Differences for heat and sun about latitude
Low latitudes have higher temperatures and more concentrated sunlights than high latitudes.
Difference of temperature every 100 m
-0.6°C
Meaning of aspect
The particular direction of the slopes.
Ideal aspect for the vineyards
South-west aspect for cool climate, south-east aspect for warm climate. (northern hemisphere)
Pros/cons of slopes
✅ Slopes can provide shallower, poorer soils and better drainage, shelter from winds and rain, and protection from frosts.
❌ Soil erosion and inability to use machinery.
ENSO
El Niño-Southern Oscillation is a climatic cycle in the Pacific Ocean. Two opposite phases: El Niño and La Niña. El Niño starts when warm water in the western Pacific Ocean moves eastwards. The eastern Pacific Ocean becomes warmer, so high levels of rainfall (a problem for pollination and fruit set, increased vigour) and risk of hurricanes (destructive influence) in South America and California, warmer temperatures and drier conditions in the Pacific Northwest (Washington and Oregon), and warmer temperatures and drought conditions (vine stress and vine damage) in Australia. It occurs once every 3–7 years. La Niña is caused when the eastern Pacific Ocean is cooler than average. Cooler and wetter conditions in Pacific Northwest and Australia; warmer and drier conditions in California and South America.
Pros of proximity to water for temperatures
Water heats up and cools down more slowly than dry land (Finger Lakes, Carneros).
Water surface reflects sunlights.
Pros/cons of winds on the vineyard
✅ Warming or cooling influence. Reduce humidity and stagnant air (otherwise fungal diseases). Increase evapotranspiration rates in the vine (more water is needed).
❌ Strong winds can damage vines (low yields, high equipment and labour costs). Some solutions could be rows of trees planted at the edges of vineyard (competition with water and nutrients) or fences installation (less aesthetic and maintenance).
Characteristics of the soil that influence the soil temperature
Drainage, structure, and colour.
Temperature differences based on the colour soils
Light colours (chalk, Champagne or Sancerre) reflects sunlights (increment of photosynthesis and grape ripening). In warm climate, an increment of temperatures in the warmest part of the day. Dark colours (volcanic, Etna) absorb more energy and re-radiate most of it when temperatures are cooler (night). Useful in cool climates or for late-ripening grapes (colour development and acid degradation during the night). Stony soils (if the underlying soil is slightly damp) absorb heat and release it during the night (stone and water are good conductors).
Definition of mist
Mists are formed by tiny drops of water collecting in the air just above an area ground or water. Usually, when air is rapidly cooled, causing water vapour in the air to condense.
Definition of fog
Fog is dense mist.
Consequences of fog presence
Fog and clouds can limit sunlight (photosynthesis), so low temperatures, slowing down sugar accumulation and acid degradation in the grapes.
Mist and fog can increase humidity (fungal diseases).
Definition of diurnal range
The average difference between day-time and night-time temperatures.
Minimum rainfall per year
500 mm in cool climates
750 mm in warm regions
The reasons why vine needs water
Turgidity, photosynthesis and regulating its temperature.
Effects of water in the late-ripening phase
Too much water available late in the ripening period can cause dilution of sugars in the grapes and even grape splitting, botrytis. A water deficit late in ripening may lead to grape shrivel and the grapes may not reach the desired level of ripeness.
Consequences of rainfall during pollination and fruit set
Uneven ripening or lower yields.
Soil characteristics that influence the water availability for the vine’s roots
How easily the water drains, the water-holding properties of the soil and the soil depth.
Soil drainage and water retention depend on the soil structure and texture (Hawkes Bay with 800 mm requires sometimes irrigation because of high draining soil, Jerez with 650 mm has albariza that has good water retention). Water-logged soils are harmful to the vine.
Meaning of evapotranspiration rate
The amount transpiration of the vine, combined with the evaporation of water from the soil surface. It depends on the temperature, humidity and wind.
Consequences of water-logged soils
Reduction of the amount of oxygen available to the roots, which slows their growth and eventually kills the vine.
Nutrients for the vine
Nitrogen, potassium, phosphorus, calcium, magnesium.
Nitrogen - what it is, excess, scarcity
Essential for vine growth, has an impact on vine vigour and on grape quality. Too much: excessive vegetative growth (sugars in the growing shoots and leaves), so the canopy can cause shading and poor ventilation. Too little: reduced vigour and yellow leaves, grapes with low nitrogen levels can have problems during fermentation. High quality grapes with a restricted supply of nitrogen.
Potassium - what it is, excess, scarcity
Essential for vine growth, helps to regulate the flow of water. Too much: uptake of magnesium (reduced yields and poor ripening), high pH in the grapes. Too little: low sugars, reduced grape yields and poor vine growth.
Phosphorous - what it is, excess, scarcity
Important for photosynthesis. Not a lot of quantities needed, naturally present in the soil. Too little: poorly developed root systems, then reduced vine growth and low yields.
Calcium - what it is, excess, scarcity
Important role in the structure of plant cells and in photosynthesis. Too little (rare): a negative influence on fruit set.
Magnesium - what it is, excess, scarcity
Key role in photosynthesis (chlorophyll). Too little: reduced grape yields and poor ripening.
Meaning of texture of the soil
It describes the proportions of the mineral particles of sand, silt, and clay. Different texture means different ability to hold nutrients (high proportion of clay is finely textured and it is good to hold nutrients, sandy soil is the opposite).
Meaning of structure of the soil
It describes how the mineral particles in the soil form aggregates. The size, shape and stability of these aggregates are also important for determining water drainage, root growth and workability of the soil. Soils with high content of clay can be hard to penetrate because of aggregates.
Explanation of soil
The upper layer of the earth and is typically made up of geological sediment, organic remains in the form of humus, and the pores in between the sediment that contain water and air. Sediment comes from the weathering of bedrock (solid rock).
Mineralisation
The process by which organisms that live in the soil (bacteria, fungi, earthworms) convert organic nutrient components into either humus or inorganic nutrient compounds so the vine can take up them.
Nutrients that are needed for vine growth
Nitrogen, potassium, and phosphorus.
Nutrients that are needed for photosynthesis
Nitrogen, phosphorus, calcium, and magnesium.
Explanation of region’s climate
The annual pattern of temperature, sunlight, rainfall, humidity and wind averaged out over several years (usually 30).
GDD
GDD (Growing Degree Days) is a model (5 ranges, Winkler Zone I is the coolest and Winkler Zone Z is the hottest) of heat summation during the growing season, by Amerine and Winkler (1944).
1) -10 (°C) or -50 (°F) from avg temperature of a month in the growing season (Apr-Oct or Oct-Apr);
2) multiply the result for the days of the month;
3) make the same for each month of the growing season and add together the totals.
Hugling Index
1978, it’s similar to GDD, using mean and maximum temperatures and the increased day length at high altitudes. Split into ranges, the most suitable grape varieties mapped to each range. Used in Europe.
MJT
Mean Temperature of the Warmest Month was created by Smart and Dry (1980) and it uses the mean temperature of July (January in the southern hemisphere) as well as measures of continentality, humidity, and hours of sunshine. Six bands.
GST
Growing Season Temperature uses the mean temperature of the growing season. Grouped into climatic bands (from cool to hot). Very closely correlated to GDD.
- Cool, below 16.5°C;
- Moderate, between 16.5°-18.5°C;
- Warm, between 18.5°-21°C;
- Hot, over 21°C.
Köppen’s Classification
It considers both temperature and rainfall. For the wine regions in temperate zones. Three categories: Maritime, Mediterranean, Continental.
Maritime climate - what it is, example
Low difference between summer and winter, rainfall evenly spread during the year, long growing season, no risk of water stress. Bordeaux.
Mediterranean climate - what it is, example
Low difference between summer and winter, rainfall during fall/winter months, dry summer, long growing season. Napa Valley and Coonawarra.
