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.
Continental climate - what it is, example
Big difference between summer (hot) and winter (cold), unpredictable rainfall. Burgundy and Alsace.
Range of temperature classification for GST
Cool – GTS below 16.5°C
Moderate – GTS between 16.5°-18.5°C
Warm – GTS between 18.5°-21°C
Hot – GTS over 21°C
Temperatures for cool climate
GTS below 16.5°C
Temperatures for moderate climate
GTS between 16.5°-18.5°C
Temperatures for warm climate
GTS between 18.5°-21°C
Temperatures for hot climate
GTS over 21°C
Explanation of Continentality
The measure of difference between the annual mean temperatures of the hottest and coldest months.
Explanation of region’s weather
The annual variation that happens relative to the climatic average.
Factors in the wine production that weather can influence
- Wines (vintage variation), so acid levels, tannin, aroma/flavour ripeness.
- Yields, due to rain (fungal disease), spring frost (reductions in yield).
Consequences of climate change
Rise in temperature (increment of evapotranspiration, water stress, faster vine cycle), effects on aroma compounds, changes in the geographical distribution of rainfall, greater frequency of extreme weather events, possibility to grow grapes in new regions (previously they were too cold).
What to do against climate change
Apply sustainable techniques, choice of site selection, planting material, different vineyard management.
Elements that constitute the growing environment
- Temperature and Sunlight
- Water
- Nutrients
- Climate Classifications
- Weather
- Climate Change
Factors that affect temperature and sunlight
Latitude, altitude, slopes and aspect, proximity to water, winds, characteristics of the soil, clouds, mist and fog, diurnal range.
Factors that affect water availability
Rainfall, characteristics of the soil and land, evapotranspiration rate.
Factors that affect nutrient availability
Rainfall, characteristics of the soil and land, evapotranspiration rate, soil pH, soil health.
Aims of conventional viticulture
The aims are to raise production levels and reduce labour requirements. So, mechanisation, chemical inputs, irrigation, clonal selection.
Pros/cons of monoculture
✅
- mechanisation;
- reduction of competition from other plants;
- be specific about the requirements of the vine (irrigation, nutrition level, treatments against hazards, pests and diseases), increase yields while reducing costs.
❌
- plants are more prone to diseases, so more treatments;
- depleting of nutrients, then use of fertilisers;
- chemical residues, then environmental damage.
Aims of sustainable viticulture
- Promote natural ecosystems.
- Maintain biodiversity.
- Manage waste.
- Minimise chemical treatments and energy use.
- Reduce the impact on the wider environment.
Pros/cons of sustainable viticulture
✅
- thoughtful approach to grape growing;
- deployment of scientific understanding of the threats to successful grape growing to minimise interventions;
- reduction of synthetic and traditional treatments;
- cost saving.
❌
- no protection of the terms, so no clear set of standards;
- nationwide standards can be set too low (New Zealand).
Aims of organic viticulture
The aim is to improve the soil and the range of microbes and animals, so the health and disease-resistance of the vine. No use of man-made fertilisers, fungicides, herbicides and pesticides. Key features:
- application of compost (slow release of nutrients by breaking down the soil, improves the soil and increases biomass);
- cover crops (prevent soil erosion and contribute to the improvement of the soil life);
- natural fertilisers (animal dung, natural calcium carbonate) to restore the natural balance of the vineyard;
- reducing monoculture by growing cover crops, planting hedges, establishing “islands” of biodiversity.
Use of traditional remedies (sulfur and copper sulfate) to combat mildews, and monitor the weather to determine the right moment for the treatment.
Build-up of the heavy metal, copper, is no good for the soil, so it’s preferred the careful use of longer-lasting synthetic chemical sprays.
Introduction of natural predators and ecosystem mechanisms (Bacillus subtilis against grey rot, sexual confusion to limit the populations of moths and mealy bugs).
Pros/cons of organic viticulture
✅
- health and disease-resistance of the vine and health of the soil are the central aims of the grape grower;
- reduction of chemical treatments;
- saving the cost of synthetic chemicals.
❌
- possible small reduction in yield;
- possibility of significant reductions in yield in difficult years;
- increased reliance on copper sprays (build-up of heavy metal in the soil);
- cost and time for certification.
Aims of biodynamic viticulture
Ideated by Rudolf Steiner and Maria Thun through organic practices, cosmology, philosophy. The vineyard soil is seen as a part of a connected system with the planet Earth, the air and other planets. Practitioners adapt their grape growing practices to coincide with the cycles of the planets, moon and stars.
Types of preparation for biodynamic viticulture
- Preparation 500 (horn manure)
- Preparation 501 (horn silica)
- Compost (Preparations 502-507)
Preparation 500
Horn manure – stuffing cow manure into a cow’s horn and burying the horn in the soil during winter, dug up, stirring the contents into water (vortex), so water memorises the power of preparation; sprayed onto the soil.
Preparation 501
Horn silica – ground quartz into cow’s horn, burying for 6 months, dug up, dynamised, sprayed onto soil.
Difference between manure and silica
Manure to catalyse humus formation, silica to encourage plant growth.
Compost in biodynamic viticulture
Activation of biodynamic compost by starters (yarrow, chamomile, nettle, oak bark, dandelion or valerian); they’re preparations 502-507 and they assist with the decomposition of the compost.
Pros/cons of biodynamic viticulture
✅
- health and disease-resistance of the vine and health of the soil are the central aims of the wine grower;
- reduction of chemical treatments;
- saving the cost of synthetic chemicals.
❌
- possible small reduction in yield;
- possibility of significant reductions in yield in difficult years;
- increased reliance on copper sprays (build-up of heavy metal in the soil);
- cost and time for certification.
Aims of precision viticulture
Use of data collected from the vineyard (soil, vigour, topography, plant growth) to respond to changes from plot to plot and from row to row. Collected by sensors on aircraft (remote) or on a tractor (proximal).
GPS (Global Positioning System) and GIS (Geographical Information Systems) allow the presentation of the data on maps.
Interventions are relative on the affected area.
Part of sustainable or organic viticulture.
Pros/cons of precision viticulture
✅
- detailed understanding of variations;
- tailor a wide range of interventions.
❌
- initial cost of remote data collection;
- cost of sensors and software and interpretation of data.
Wine factors influenced by the site selection
Style, quality and price.
Factors to consider during the site selection
- natural resources and climate;
- price of the land within desirable geographical indications (area classified as Burgundy Grand Crus is much more expensive than that as Vin de France);
- location, layout and topography of the site (vineyard in a frost pocket, so cost for frost protection strategies);
- eventually steep slopes (no mechanisation);
- irrigation (costs of water and system);
- ease of access and distance from the winery (limit the risk of oxidation and microbial spoilage);
- proximity to towns (labour, supplies, cellar door customers, retail or distribution).
Characteristics of site selection to produce high volume, inexpensive or mid-level wines
Flat (mechanisation) and fertile site in a warm (full ripening, optional irrigation) and dry (no fungal diseases) climate such as Central Valley in Chile.
Characteristics of site selection to produce premium and super-premium wines
It’s needed to consider the style of the wine (acidity, colour, tannins, aroma compounds); maximise potential to ripen the grapes, so most sunshine in cool climates (Rheingau, Germany), cool sites thanks to altitude for warm climates (Lújan de Cuyo, Argentina) or see breezes (Casablanca, Chile).
Soil factors influenced by its structure
Root penetration, water drainage, nutrient holding capacity and workability.
Factors to assess and rectify during soil preparation
- drainage and structure of the soil (make viticulture viable);
- mineral composition (farmyard manure, compost and fertilisers to increase nutrients and organic matter);
- presence of pests or unwanted plants (remove old roots, eventual use of systemic herbicides).
Grape variety characteristics related to climatic factors
- aroma/flavour properties;
- time of budding (early budding such as Chardonnay are more prone to spring frost than late budding such as Riesling);
- duration of annual life-cycle (early ripening such as Chardonnay and Pinot Noir are best suited to cool climates, so they can reach the right ripeness before wet and cold weather starts towards late autumn; in a warm climate they gain sugar and lose acidity too rapidly);
- tolerance of drought (ability against high levels of water stress such as Grenache in southern Rhône, inland Spain or McLaren Vale);
- resistance to disease (less susceptible to fungal diseases; Cabernet Sauvignon is less susceptible to grey rot than Merlot);
- winter hardiness (tolerance against very cold temperatures, Vidal and Riesling in Ontario and Finger Lakes);
- vigour (excessive shoot growth, Sauvignon Blanc on fertile soils with plentiful water).
Grape variety characteristics related to wine production
- style of wine (Gamay or Grenache for low tannin, fruity red and early drinking wine);
- yield (inexpensive wines from high yielding grape varieties such as Grenache);
- cost (related to the grape growth, Pinot Noir is more prone to diseases);
- law (restrictions on grape varieties that can be used for the wine, Prosecco-Glera);
- availability (quarantine procedures when introducing new planting material;regions with a large range of choices);
- market demand.
Factors to consider during the choice of clone
Similar to the grape variety, but the choice is less impactful than grape variety and much less affected by legislation and consumer popularity.
Factors to consider during the choice of rootstocks
- pests (in addition to phylloxera, also tolerance against root-knot nematodes – Ramsey and Dog Ridge);
- water (hybrids of V. Rupestris and V. Berlandieri such as 110R or 140R are highly tolerant of drought, Riparia Gloire from V. Riparia is tolerant on water-logged soils, 1103 Paulsen from V. Berlandieri is tolerant of soils with high salinity);
- soil pH (can alleviate problems caused by soils with very low or high pH – 99R and 110R, hybrids of V. Rupestris and V. Berlandieri, are ideal for low pH soils, 41B from V. Berlandieri is ideal with high pH);
- vigour (can moderate or enhance the vigour – low vigour rootstocks such as 420A and 3309C from V. Riparia for cool climate, high vigour rootstock such as 140R from V. Rupestris for unfertile soils and dry conditions).
Ideal vine age for maximum yield of fruit
Between 10 and 40 years.
The smallest vine age for harvest in the EU
4 years old.
Synonyms of old vines
Vieilles vignes or viñas viejas.
Soil health - what it is, related factors
The ability to support the vine, enabling it to grow and produce fruit. It’s related to:
- structure of the soil (good drainage, sufficient water-holding capacity, sufficient oxygen, ability to resist erosion and to allow the roots to penetrate to sufficient depth);
- amount of organic matter and humus (decomposing organic matter supplies nutrients, humus improves the structure of the soil and its water-holding capacity);
- number of living organisms (earthworms and microbes break down organic matter into humus and inorganic nutrients that are accessible to the vine);
- total amount of available nutrients.
Methods to control the level of nutrients in the soil during the growing season
Direct application of nutrients, promotion of biological activity and soil structure, management of weeds (also to reduce frost risk).
Fertilisers - what they are, types, pros/cons
Help the growth of young vines (before planting). Can correct any deficiencies in the soil (established vineyard). Too much can cause excess vigour and an unbalanced vine.
Organic – from fresh or composted plant or animal material (manure or slurry).
✅ cheap or free, promote the living matter in the soil, gradually release
❌ labour for incorporation, bulky (transport)
Mineral – from the ground or chemically manufactured.
✅ tailored, readily available, concentrated, transport
❌ no benefits for organisms, no improving soil structure, expensive
Organic fertilisers - what they are, pros/cons
From fresh or composted plant or animal material (manure or slurry).
✅ cheap or free, promote the living matter in the soil, gradually release
❌ labour for incorporation, bulky (transport)
Mineral fertilisers - what they are, pros/cons
From the ground or chemically manufactured.
✅ tailored, readily available, concentrated, transport
❌ no benefits for organisms, no improving soil structure, expensive
Cultivation - what it is, pros/cons
Weed control method by ploughing the soil to cut or disturb the weeds’ root systems.
✅ no chemicals, enables fertiliser, mown cover crops at the same time
❌ can damage the soil’s structure (repeated), cost, encourages the weeds to grow back, can increase vine vigour
Herbicides - what they are, types, pros/cons
Chemical sprays that kill weeds:
- pre-emergence - before weeds establish, persist in the surface layers of the soils, absorbed by the weeds’ roots, inhibit germination of young seedlings;
- contact – on established weeds, kill the green parts that they contact;
- systemic – on established weeds, taken in by the leaves, travel up and down the weed in the sap and kill the whole plant.
✅ cheap, highly effective, less damage to structure than cultivation
❌ poisoning, no effect on long periods, increase vine vigour, not allowed in organic and biodynamic
Pre-emergence herbicides
Before weeds establish, persist in the surface layers of the soils, absorbed by the weeds’ roots, inhibit germination of young seedlings.
Contact herbicides
On established weeds, kill the green parts that they contact.
Systemic herbicides
On established weeds, taken in by the leaves, travel up and down the weed in the sap and kill the whole plant.
Animal grazing - what it is, pros/cons
Allow animals (sheep) to graze in the vineyard.
✅ no chemicals (organic and biodynamic agriculture), manure, meat for humans
❌ can eat leaves and grapes, labour to care animals, susceptible to vineyard pesticides
Cover crop - what it is, pros/cons
Plants that are specifically planted with beneficial effect on the vineyard (legumes, cereals):
- suppress weeds;
- improve soil structure;
- compete with the vine in fertile soils;
- manage soil erosion;
- enhance biodiversity;
- provide a surface to drive on;
- green manure (organic matter for the fertilisation of the soil).
✅ no chemicals (organic and biodynamic agriculture), influence vigour of the vine, good surface for machinery
❌ reduction in vine vigour (poor soils), labour, no for steep slopes
Mulching - what it is, pros/cons
Spreading of matter onto the vineyard soil to suppress the growth of weeds. Biodegradable materials (straw, bark chips).
✅ no chemicals (organic and biodynamic agriculture), reduce water evaporation (dry climate), source of nutrients and humus
❌ bulky, thick layer, can increase vigour
The ways to increase the efficiency of water in the vineyard
- using water-efficient irrigation systems and techniques combined with better monitoring of water take-up by the vines (dripper systems and regulated deficit irrigation);
- using drought-tolerant grape varieties (Grenache) and rootstocks (140R);
- reducing evaporation (applying mulch);
- reducing competition (removing weeds);
- increasing humus levels (adding compost);
- promoting deep growth (through cultivation).
Types of irrigation systems
Drippers, flood and channel irrigation, overhead sprinklers.
Drippers - what they are, pros/cons
Thin water pipes laid along each row, typically tied to the lowest trellis wire; drippers are fitted at appropriate intervals, far enough away from the vines to encourage the roots to grow and seek out water.
✅ economic use of water, water control (rows or vines block), supply fertilisers (fertigation), used on slopes
❌ cost (high for installation and moderate for maintenance), clean water, maintenance, no frost protection
Flood - what it is, pros/cons
Water behind a sluice and released to flood the vineyard.
✅ cheap (installation and maintenance)
❌ no use on slopes, no control, a little quantity is absorbed by the vine
Channel irrigation - what it is, pros/cons
Water flows down furrows dug between the vine rows.
✅ cheap (installation and maintenance)
❌ no use on slopes, no control, a little quantity is absorbed by the vine
Overhead sprinklers - what they are, pros/cons
Pump water and shower it over the vineyard.
✅ frost protection
❌ cost (installation, maintenance), a big quantity of water is needed
RDI - what it is, pros/cons
Regulated Deficit Irrigation is a system of timing and regulating the amount of irrigation. Vine is put under mild to moderate water stress for a specified time within the growing season (usually between fruit set and véraison). It’s used the dripper system. RDI is easiest in regions with a dry growing season and sandy or loam soils that dry out and can be re-wetted quickly. Often used for black grapes (small grape, thick skin, high concentration).
✅ control on vine growth and grape development, less use of water
❌ timing of water application and monitoring of the soil, cost (equipment to monitor)
Drainage system - what it is, pros/cons
Artificial system to drain the water, if climate with high rainfall (Médoc). Installation before planting the vineyard.
✅ healthy and balanced vines, allows mechanisation
❌ cost (installation and maintenance)
Fertigation
Method of fertilizer application in which fertilizer is incorporated within the irrigation water by the drippers.
Aims of canopy management
- Maximise the effectiveness of light interception.
- Reduce the shade.
- Ensure that the microclimate for the grapes is uniform.
- Promote balance between the vegetative and reproductive functions of the vine.
- Ease mechanisation and/or manual labour.
- Promote air circulation (no diseases).
How canopy management can influence yield
Promoting a greater number of inflorescences developing inside the latent bud, increasing the vine’s photosynthetic capacity, reducing fungal disease pressure.
How canopy management can influence the quality
Increased sugar levels (photosynthesis), increased tannin levels and greater polymerisation, enhanced anthocyanin development in black grapes, decreased malic acid, increased levels of some favourable aroma precursors and aroma compounds (terpenes for Muscat), decreased methoxypyrazines (herbaceous characters for Cabernet Sauvignon).
Under-cropping
The yield of fruit is too low for the vigour of the vine, shoot growth continues (not much fruit), negative effect on grape formation and ripening (shoots and leaves compete for sugars and nutrients), dense and shady canopy (lack of sunlights for the grape) and a possible reduction of bud fruitfulness (vegetative cycle).
Over-cropping
The yield of fruit is too high for the vigour of the vine, weakening of the vine (use of carbohydrates from roots, trunks and cordons, they’re needed for the next growing season).
Yield
The measure of the amount of fruit produced, measured per vine or over a set area. There is a link between the yield of a vine and the fruit quality in that vine.
Vine density
The number of vines that are planted per hectare of vineyard. It’s influenced by the vigour of the vine, the type of trellising system used, and what access is needed between the vines. Low density is cheaper than high density.
Factors that influence row orientation
Both climatic (north-south orientation for the most even sunlight exposure, west side is warmer so more shading, orientation at 90° angle to the direction of the wind) and logistic factors (parallel to the longest side of the vineyard, up and down the slopes with an angle greater than 10% rather than across).
Factors that influence training and trellising methods
- vigour of the vine – natural resources available to the vine, the planting material, and the presence of any disease;
- topography of the site – steep slopes or windy sites limit the choice;
- need for mechanisation – some systems are most suited.
Vine training - what it is, types
The shape of the permanent wood of the vine:
- head – little permanent wood (trunk) with a few short stubs on the top, spur-pruned or replacement cane-pruned;
- cordon – trunk and one or more permanent horizontal arms (cordons), spur-pruned, longer to establish than head training.
Vine pruning - what it is, types
The removal of unwanted parts of the vine (winter and summer).
Types of winter pruning
- spur – short sections of one-year-old wood that have been cut back to only 2/3 buds, easier and allows mechanisation, cordon or head training;
- replacement cane – longer sections of one-year-old wood and can have 8/20 buds, laid down horizontally and needs trellis system, more complex and a lot of labour.
Trellis systems
Permanent structures of posts and wires that help to support and position the vine’s shoots.
Untrellised vineyards - what they are, pros/cons
Usually bush vines (head-training and spur-pruned), simple and inexpensive to develop, for hot and sunny regions (La Mancha), no mechanisation, ideal in dry regions (limit the vine’s vigour otherwise dense canopy).
Trellised vineyards - what they are, pros/cons, types
Very common, shoots can be spread out to maximise light interception, increase air flow, aid mechanisation, but expensive and need maintaining, depend on the vine’s vigour. VSP or complex training systems.
VSP - what it is, pros/cons
Vertical Shoot Positioning is the most common and the most simple, used on head-trained, replacement cane-pruned (Guyot training, single or double) vines and cordon-trained, spur-pruned vines, the vine’s shoot are trained vertically and are held in place onto the trellis forming a single narrow canopy, ideal for vines with low or moderate vigour.
Complex training systems - what they are, pros/cons, types
For the most vigorous grape varieties, difficult to manage and mechanise, horizontal canopy for GDC (Geneva Double Curtain) or Lyre, vertical canopy for Smart-Dyson or Scott-Henry.
Guyot
VSP system, head-trained and replacement cane-pruned. It can be single or double.
Techniques for summer pruning
- disbudding;
- shoot removal;
- shoot positioning;
- pinching;
- shoot trimming;
- leaf removal;
- crop thinning or green harvesting.
Disbudding during summer pruning
Removal of buds that are poorly positioned and management of the vine balance and yields (high number of buds in winter in case of spring frost).
Shoot removal during summer pruning
Removal of (lateral) shoots that are infertile or poorly positioned (open canopy).
Shoot positioning during summer pruning
Shoots are tucked into the trellis wires (organise canopy and facilitate mechanisation).
Pinching during summer pruning
Removal of shoot tips at flowering to improve fruit set
Shoot trimming during summer pruning
Cutting shoots (limit growth) and reduce canopy thickness (less carbohydrates competition, better air circulation).
Leaf removal during summer pruning
Removal of leaves to reduce shading of fruits (sunburn in warm regions).
Crop thinning or green harvesting during summer pruning
Removal of bunches of grapes to increase ripeness of other grapes.
Head training
Little permanent wood (trunk) with a few short stubs on the top, spur-pruned or replacement cane-pruned.
Cordon training
Trunk and one or more permanent horizontal arms (cordons), spur-pruned, longer to establish than head training.
Spur pruning
Short sections of one-year-old wood that have been cut back to only 2/3 buds, easier and allows mechanisation, cordon or head training.
Replacement cane pruning
Longer sections of one-year-old wood and can have 8/20 buds, laid down horizontally and needs trellis system, more complex and a lot of labour.
Drought hazard - what happens, hot to solve
WH: Vine closes its stomata on the leaves, so reduction of photosynthesis. Then, the growth slows down, grape size is reduced. Unripe grapes and lower yields, vine loses its leaves and dies.
HTS: Irrigation systems (initial design of the vineyard, laws), rootstocks (110R, 140R), drought-tolerant variety (Garnacha).
Excess of water hazard - what happens, hot to solve
WH: Too much vegetative growth (less grape ripening). Fungal diseases (high humidity). Waterlogging in case of soils are not free draining (less oxygen for the roots) or compaction of the soils (difficult to work).
HTS: Site selection on slope or free-draining soil, drainage system.
Untimely rainfall hazard - what happens, hot to solve
WH: Millerandage or coulure during pollination or fruit set (low yield). Less ripening in mid-season. Before véraison, better grape ripening and fewer shoots growth. Grapes swollen with water and splitting if close to harvest.
HTS: Site selection (climate, slope, drainage), monitoring weather forecasts (possibility of early harvest).
Freeze hazard - what happens, hot to solve
WH: Vine can be seriously damaged or even killed under -20°C. Graft, canes or cordons are the most delicate parts.
HTS: Site selection (hillside sites, bodies of water, snow can protect the vine), choice of varieties (Cabernet Franc or Riesling, American and Mongolian vine species), protecting vines (building up soil around the vine graft, burying vines, pruning to have several trunks).
Frost hazard - what happens, hot to solve
WH: Cold air below 0°C at ground level, freezing water in the vine’s growing buds and shoots. Advective frosts: large volumes of cold air moving in from very cold areas. Radiative frosts: result of heat being lost on still, cool nights.
HTS: Reducing the risk through site selection (hillside), delaying pruning (postpones budburst), late budding variety (Riesling), training high the vine (cold air near the ground), bare soil between the vines absorbing heat during the day and radiates it at night. When frost threatens through water sprinklers (low cost, only equipment and water), wind machine (warranted when 20% chance of a damaging radiation frost in any one year), oil or propane gas burning heaters and wax candles (high cost of fuel and labour, low heating efficiency and contribution to air pollution).
Hail hazard - what happens, hot to solve
WH: Damage and rip young shoots and leaves. Possibility of Botrytis. Reduction of yields.
HTS: Rockets fired into thunderclouds (seeding them with silver iodide), netting (shading), plots in different areas, crop insurance.
Sunburn hazard - what happens, hot to solve
WH: Limited grape transpiration. Grapes reach higher temperatures than leaves and become burnt. Scars on the skin. Browning of grapes (bitter taste) and susceptibility to rot. Reduction of yields.
HTS: Design of the vineyard (row orientation and aspect), canopy management, additional irrigation, special agricultural sunscreen spray or shading the vine with a cloth or net.
Fire hazard - what happens, hot to solve
WH: Typically in hot and dry countries. Climate is changing. Cover crops and organic mulches provide fuel. Several damages to vines and trellising.
HTS: Fire detectors and sprinklers, water tank, training employees for an emergency.
Smoke taint hazard - what happens, hot to solve
WH: Smoky or plastic aromas in the final wine if smoke during the growing season. Aroma compounds in smoke bind with sugars and form aroma-less precursors.
HTS: Analytical or micro-vinification tests. Grapes handling. Hand harvesting, gentle or whole bunch pressing, low fermentation temperatures, reduced maceration times. Flash détente and reverse osmosis.
Major hazards for the vine
- Drought.
- Excess of water.
- Untimely rainfall.
- Freeze.
- Frost.
- Hail.
- Sunburn.
- Fire.
- Smoke taint.
What happens in case of drought hazard
Vine closes its stomata on the leaves, so reduction of photosynthesis. Then, the growth slows down, grape size is reduced. Unripe grapes and lower yields, vine loses its leaves and dies.
How to solve the drought hazard
Irrigation systems (initial design of the vineyard, laws), rootstocks (110R, 140R), drought-tolerant variety (Garnacha).
What happens in case of excess of water hazard
Too much vegetative growth (less grape ripening). Fungal diseases (high humidity). Waterlogging in case of soils are not free draining (less oxygen for the roots) or compaction of the soils (difficult to work).
How to solve the excess of water hazard
Site selection on slope or free-draining soil, drainage system.
What happens in case of untimely rainfall hazard
Millerandage or coulure during pollination or fruit set (low yield). Less ripening in mid-season. Before véraison, better grape ripening and fewer shoots growth. Grapes swollen with water and splitting if close to harvest.
How to solve the untimely rainfall hazard
Site selection (climate, slope, drainage), monitoring weather forecasts (possibility of early harvest).
What happens in case of freeze hazard
Vine can be seriously damaged or even killed under -20°C. Graft, canes or cordons are the most delicate parts.
How to solve the freeze hazard
Site selection (hillside sites, bodies of water, snow can protect the vine), choice of varieties (Cabernet Franc or Riesling, American and Mongolian vine species), protecting vines (building up soil around the vine graft, burying vines, pruning to have several trunks).
What happens in case of frost hazard
Cold air below 0°C at ground level, freezing water in the vine’s growing buds and shoots. Advective frosts: large volumes of cold air moving in from very cold areas. Radiative frosts: result of heat being lost on still, cool nights.
How to solve the frost hazard
Reducing the risk through site selection (hillside), delaying pruning (postpones budburst), late budding variety (Riesling), training high the vine (cold air near the ground), bare soil between the vines absorbing heat during the day and radiates it at night. When frost threatens through water sprinklers (low cost, only equipment and water), wind machine (warranted when 20% chance of a damaging radiation frost in any one year), oil or propane gas burning heaters and wax candles (high cost of fuel and labour, low heating efficiency and contribution to air pollution).
What happens in case of hail hazard
Damage and rip young shoots and leaves. Possibility of Botrytis. Reduction of yields.
How to solve the hail hazard
Rockets fired into thunderclouds (seeding them with silver iodide), netting (shading), plots in different areas, crop insurance.
What happens in case of sunburn hazard
Limited grape transpiration. Grapes reach higher temperatures than leaves and become burnt. Scars on the skin. Browning of grapes (bitter taste) and susceptibility to rot. Reduction of yields.
How to solve the sunburn hazard
Design of the vineyard (row orientation and aspect), canopy management, additional irrigation, special agricultural sunscreen spray or shading the vine with a cloth or net.
What happens in case of fire hazard
Typically in hot and dry countries. Climate is changing. Cover crops and organic mulches provide fuel. Several damages to vines and trellising.
How to solve the fire hazard
Fire detectors and sprinklers, water tank, training employees for an emergency.
What happens in case of smoke taint hazard
Smoky or plastic aromas in the final wine if smoke during the growing season. Aroma compounds in smoke bind with sugars and form aroma-less precursors.
How to solve the smoke taint hazard
Analytical or micro-vinification tests. Grapes handling. Hand harvesting, gentle or whole bunch pressing, low fermentation temperatures, reduced maceration times. Flash détente and reverse osmosis.
Major pests for the vine
- Phylloxera.
- Nematodes.
- Grape moths.
- Spider mites.
- Birds.
- Mammals.
Phylloxera pest - what happens, hot to solve
WH: It was identified in Europe in 1863 and was introduced from USA. Aphid-like insect feeds on and lays eggs on the roots, it weakens vine roots and causes a swelling until crack and then rot. Spread through crawling, flying, human transportation (leaf trimmers, harvesters, irrigation water). Vines die (drought), yellow eggs and insects on the roots, swelling on older roots, pale green leaf galls on under-surface of the leaves, slow growth and leaf yellowing in three years (die in five years).
HTS: Grafting European vines onto American rootstock (V. Berlandieri, V. Riparia, V. Rupestris). Create rootstock hybrids between various American species in order to balance the level of protection to phylloxera and resistance to lime in the soil.
Nematodes pest - what happens, hot to solve
WH: Tiny worms, feed off vine roots, high reduction of yields and vigour. Slow and gradual decline, transmission of viral diseases (fanleaf virus). Root-knot nematode and dagger nematode. Either already present in the soil or spread by unclean nursery stock, irrigation water or vehicles.
HTS: No elimination, only management. Initial soil analysis. Leave the soil fallow, fumigate the soil (chemicals are banned in most regions, otherwise cover crop of mustard plant which contains compounds working as biofumigants killing nematodes), rootstock (Ramsey and Dog Ridge).
Grape moths pest - what happens, hot to solve
WH: They attack flowers in spring and grapes later. Wounds created are vulnerable to bacteria and fungi attacks. Light brown apple moth in Australia, the European grapevine moth in southern Europe, and the grape berry moth in central and eastern North America.
HTS: Biological control (Bacillus thuringiensis, pheromone capsules, natural predators), insecticides.
Spider mites pest - what happens, hot to solve
WH: Feed on the surface cells of leaves. Discolouration of the leaves, reduction in photosynthesis, delayed ripening and yields reduction. Pacific spider mite (California), red spider mite and two forms of yellow spider mite (Europe). Thrive in dusty and water stress conditions.
HTS: Water sprinklers and/or cover crops or mulches to reduce dust, predatory mites, pesticides.
Birds pest - what happens, hot to solve
WH: Usually starlings. Destroy entire crops. Damages allow bacteria and fungi to enter leading to rot.
HTS: Netting, bird scares or noises, falcons (sometimes).
Mammals pest - what happens, hot to solve
WH: Eat shoots, grapes and leaves. Possibility of rot by breaking the grapes. Damage trellising.
HTS: High and sunk fencing into the soil.
What happens in case of Phylloxera pest
It was identified in Europe in 1863 and was introduced from USA. Aphid-like insect feeds on and lays eggs on the roots, it weakens vine roots and causes a swelling until crack and then rot. Spread through crawling, flying, human transportation (leaf trimmers, harvesters, irrigation water). Vines die (drought), yellow eggs and insects on the roots, swelling on older roots, pale green leaf galls on under-surface of the leaves, slow growth and leaf yellowing in three years (die in five years).
How to solve Phylloxera pest
Grafting European vines onto American rootstock (V. Berlandieri, V. Riparia, V. Rupestris). Create rootstock hybrids between various American species in order to balance the level of protection to phylloxera and resistance to lime in the soil.
What happens in the case of nematodes pest
Tiny worms, feed off vine roots, high reduction of yields and vigour. Slow and gradual decline, transmission of viral diseases (fanleaf virus). Root-knot nematode and dagger nematode. Either already present in the soil or spread by unclean nursery stock, irrigation water or vehicles.
How to solve the nematodes pest
No elimination, only management. Initial soil analysis. Leave the soil fallow, fumigate the soil (chemicals are banned in most regions, otherwise cover crop of mustard plant which contains compounds working as biofumigants killing nematodes), rootstock (Ramsey and Dog Ridge).
What happens in the case of grape moths pest
They attack flowers in spring and grapes later. Wounds created are vulnerable to bacteria and fungi attacks. Light brown apple moth in Australia, the European grapevine moth in southern Europe, and the grape berry moth in central and eastern North America.
How to solve the grape moths pest
Biological control (Bacillus thuringiensis, pheromone capsules, natural predators), insecticides.
What happens in the case of spider mites
Feed on the surface cells of leaves. Discolouration of the leaves, reduction in photosynthesis, delayed ripening and yields reduction. Pacific spider mite (California), red spider mite and two forms of yellow spider mite (Europe). Thrive in dusty and water stress conditions.
How to solve the spider mites
Water sprinklers and/or cover crops or mulches to reduce dust, predatory mites, pesticides.
What happens in the case of birds pest
Usually starlings. Destroy entire crops. Damages allow bacteria and fungi to enter leading to rot.
How to solve the birds pest
Netting, bird scares or noises, falcons (sometimes).
What happens in the case of mammals pest
Eat shoots, grapes and leaves. Possibility of rot by breaking the grapes. Damage trellising.
How to solve the mammals pest
High and sunk fencing into the soil.
Major fungal diseases for the vine
- Powdery mildew.
- Downy mildew.
- Grey rot.
- Eutypa dieback.
- Phomopsis can and leaf spot.
- Esca.
- Black rot.
- Black-foot disease.
- Bot canker.
- Anthracnose.
Powdery mildew disease - what happens, hot to solve
WH: Caused by the fungus Oidium tucker. Chardonnay and Cabernet Sauvignon are more susceptible. Overwinters in buds and on canes. It attacks young, green parts of the vine (from grey patches to black). Damage young shoots, inflorescences and grapes reducing yield. Grape splitting at véraison, target to other infections. Temperature around 25°C, shady conditions. No high humidity required. Early spread in dry conditions and dense, shady canopies.
HTS: Open canopy (no shade and fewer leaves density), sulfur to prevent and treat (spraying from a couple of weeks after budburst, up to véraison), synthetic fungicides (limited applications otherwise the fungus becomes resistant).
Downy mildew disease - what happens, hot to solve
WH: Caused by Peronospora (water mould that lives within vine tissue). It attacks green parts (young leaves and flowers), reducing yields by defoliating the vine. It needs warm temperatures (20°C) and rainfall. Yellow, circular ‘oil spots’ and then white, downy fungal growth on the underside of the leaves.
HTS: Bordeaux mixture (copper sulfate and lime), fungicides (applied from a month after budburst up to véraison), good drainage and open canopy.
Grey rot disease - what happens, hot to solve
WH: Caused by Botrytis cinerea. Loss of yield and drop of quality in the wine. Grapes are vulnerable if there are any points of entry (punctures by birds/insects, rubbing by bunches). If flowers are affected, fungus stays dormant and re-emerges after véraison. Semillon, Sauvignon Blanc, Pinot Noir are most at risk (tight bunches and thin skins).
HTS: Resistant grape varieties (small grapes and thick skins such as Petit Verdot), open canopy (no leaves around bunches). Sulfur and copper are ineffective, but other fungicides can be used (applied when flowering almost complete, end of grape formation, bunch closure and véraison). Fungicides quickly become ineffective as the fungus develops resistance. Use of antagonist bacteria (Bacillus subtilis).
Eutypa dieback disease - what happens, hot to solve
WH: Fungal trunk disease that leads to rotten wood and can affect whole vineyards. Kills vines in 10 years if not tackled. Spores spread by wind. Infection through pruning wounds in moderate temperature and during rain. Short young shoots and yellow leaves. Grenache, Cabernet Sauvignon and Sauvignon Blanc are more susceptible.
HTS: Late pruning, fungicide to pruning wounds. Cut back affected trunks 5-10cm beyond symptoms and treat with fungicide. Burn dead wood, no spores spreading. Biological control (Bacillus subtilis). Remove the vine and replant it.
Phomopsis cane and leaf spot disease - what happens, hot to solve
WH: Reduction in crops. Cool and wet springs, followed by humidity and moderate temperatures. Infected canes whiten and break off easily. Shoots develop brown cracks at their bases. Leaves are affected as well. Grenache very susceptible, Cabernet Sauvignon less prone.
HTS: Fungicide (three weeks after budburst and every two weeks if wet conditions are present). Removing and burning of the affected wood. Early or late pruning (not in rainy weather).
Esca disease - what happens, hot to solve
WH: Group of organisms in a warm and dry climate. It enters the vine through pruning wounds. Tiger-striping of the leaves and spotting inside the wood. Reduction of the yield and kill the vine.
HTS: No chemical control, new pruning techniques (not during rain), biological control (Bacillus subtilis).
What happens in the powdery mildew disease
Caused by the fungus Oidium tucker. Chardonnay and Cabernet Sauvignon are more susceptible. Overwinters in buds and on canes. It attacks young, green parts of the vine (from grey patches to black). Damage young shoots, inflorescences and grapes reducing yield. Grape splitting at véraison, target to other infections. Temperature around 25°C, shady conditions. No high humidity required. Early spread in dry conditions and dense, shady canopies.
How to solve the powdery mildew disease
Open canopy (no shade and fewer leaves density), sulfur to prevent and treat (spraying from a couple of weeks after budburst, up to véraison), synthetic fungicides (limited applications otherwise the fungus becomes resistant).
What happens in the case of downy mildew disease
Caused by Peronospora (water mould that lives within vine tissue). It attacks green parts (young leaves and flowers), reducing yields by defoliating the vine. It needs warm temperatures (20°C) and rainfall. Yellow, circular ‘oil spots’ and then white, downy fungal growth on the underside of the leaves.
How to solve the downy mildew disease
Bordeaux mixture (copper sulfate and lime), fungicides (applied from a month after budburst up to véraison), good drainage and open canopy.
What happens in the case of grey rot disease
Caused by Botrytis cinerea. Loss of yield and drop of quality in the wine. Grapes are vulnerable if there are any points of entry (punctures by birds/insects, rubbing by bunches). If flowers are affected, fungus stays dormant and re-emerges after véraison. Semillon, Sauvignon Blanc, Pinot Noir are most at risk (tight bunches and thin skins).
How to solve the grey rot disease
Resistant grape varieties (small grapes and thick skins such as Petit Verdot), open canopy (no leaves around bunches). Sulfur and copper are ineffective, but other fungicides can be used (applied when flowering almost complete, end of grape formation, bunch closure and véraison). Fungicides quickly become ineffective as the fungus develops resistance. Use of antagonist bacteria (Bacillus subtilis).
What happens in the case of Eutypa dieback disease
Fungal trunk disease that leads to rotten wood and can affect whole vineyards. Kills vines in 10 years if not tackled. Spores spread by wind. Infection through pruning wounds in moderate temperature and during rain. Short young shoots and yellow leaves. Grenache, Cabernet Sauvignon and Sauvignon Blanc are more susceptible.
How to solve the Eutypa dieback disease
Late pruning, fungicide to pruning wounds. Cut back affected trunks 5-10cm beyond symptoms and treat with fungicide. Burn dead wood, no spores spreading. Biological control (Bacillus subtilis). Remove the vine and replant it.
What happens in the case of phomopsis cane and leaf spot disease
Reduction in crops. Cool and wet springs, followed by humidity and moderate temperatures. Infected canes whiten and break off easily. Shoots develop brown cracks at their bases.Leaves are affected as well. Grenache very susceptible, Cabernet Sauvignon less prone.
How to solve the phomopsis cane and leaf spot disease
Fungicide (three weeks after budburst and every two weeks if wet conditions are present). Removing and burning of the affected wood. Early or late pruning (not in rainy weather).
What happens in the case of esca disease
Group of organisms in a warm and dry climate. It enters the vine through pruning wounds. Tiger-striping of the leaves and spotting inside the wood. Reduction of the yield and kill the vine.
How to solve the esca disease
No chemical control, new pruning techniques (not during rain), biological control (Bacillus subtilis).
Major bacterial diseases for the vine
- Pierce’s disease.
- Grapevine yellows.
- Bacterial blight.
- Crown gall.
Pierce’s disease - what happens, hot to solve
WH: It quickly kills vine. The bacterium lives in the sap channels of vines, which it clogs and kills the vine in max 5 years. Transmission by sharpshooter insect. Chardonnay and Pinot Noir are more vulnerable.
HTS: No chemical control, laboratory tests for certainty. Reduce the number of vectors (no vines close to rivers), some chemical insecticides can be used, species of wasp that feeds on sharpshooter eggs. Strict quarantine for movement of plants.
Grapevine yellows disease - what happens, hot to solve
WH: Group of diseases caused by a type of bacteria. Spread by vectors (including leafhoppers) and nurseries selling untreated, diseased stock. Flavescence dorée in Europe. Delayed budburst, new shoots fail to become woody, canopy turns yellow in white varieties and red in black varieties. Drastic reduction in yields and lower quality. Vine sometimes dies and sometimes can recover after an attack. Chardonnay and Riesling are more vulnerable
HTS: No treatment available. Focus on controlling the vector (insecticides for leafhopper populations, removing the plants that host the leafhoppers). To bathe in nursery the pruning wood in hot water to kill the disease.
What happens in the case of Pierce’s disease
It quickly kills vine. The bacterium lives in the sap channels of vines, which it clogs and kill the vine in max 5 years. Transmission by sharpshooter insect. Chardonnay and Pinot Noir are more vulnerable.
How to solve the Pierce’s disease
No chemical control, laboratory tests for certainty. Reduce the number of vectors (no vines close to rivers), some chemical insecticides can be used, species of wasp that feeds on sharpshooter eggs. Strict quarantine for movement of plants.
What happens in the case of grapevine yellows disease
Group of diseases caused by a type of bacteria. Spread by vectors (including leafhoppers) and nurseries selling untreated, diseased stock. Flavescence dorée in Europe. Delayed budburst, new shoots fail to become woody, canopy turns yellow in white varieties and red in black varieties. Drastic reduction in yields and lower quality. Vine sometimes dies and sometimes can recover after an attack. Chardonnay and Riesling are more vulnerable
How to solve the grapevine yellows disease
No treatment available. Focus on controlling the vector (insecticides for leafhopper populations, removing the plants that host the leafhoppers). To bathe in nursery the pruning wood in hot water to kill the disease.
Major virus for the vine
- Fanleaf virus.
- Leafroll virus.
Fanleaf virus - what happens, hot to solve
WH: Long-standing group of diseases. Spread enormously by the move to grafted vines following Phylloxera and the inadvertent use of infected plant material. Spread also slowly by dagger nematodes. Early shoot growth is stunted, canes can grow in distorted ways, leaves are very pale and can look like a fan. Cabernet Sauvignon is susceptible.
HTS: No cure. Vines need to be removed, soil tests before re-planting with clean material.
Leafroll virus - what happens, hot to solve
WH: Group of viral diseases. Spread by grafting and mealy bugs. Yield reduction by up to half. Slower growth of roots and shoots. Extra weeks for ripening (less colour, fewer sugars, fewer carbohydrates storage). Leaves turn yellow for white varieties and red for black varieties.
HTS: Unclear symptoms sometimes. Vines need laboratory tests. No cure. Remove vines and re-plant. Open canopy because mealy bugs favour humid environments, natural predators for mealy bugs (ladybugs, lacewings).
What happens in the case of fanleaf virus
Long-standing group of diseases. Spread enormously by the move to grafted vines following Phylloxera and the inadvertent use of infected plant material. Spread also slowly by dagger nematodes. Early shoot growth is stunted, canes can grow in distorted ways, leaves are very pale and can look like a fan. Cabernet Sauvignon is susceptible.
How to solve the fanleaf virus
No cure. Vines need to be removed, soil tests before re-planting with clean material.
What happens in the case of leafroll virus
Group of viral diseases. Spread by grafting and mealy bugs. Yield reduction by up to half. Slower growth of roots and shoots. Extra weeks for ripening (less colour, fewer sugars, fewer carbohydrates storage). Leaves turn yellow for white varieties and red for black varieties.
How to solve the leafroll virus
Unclear symptoms sometimes. Vines need laboratory tests. No cure. Remove vines and re-plant. Open canopy because mealy bugs favour humid environments, natural predators for mealy bugs (ladybugs, lacewings).
Potential alcohol
The amount of alcohol that would be created by fermenting all the sugar in grape must into alcohol.
Brix
One of the scales used to measure the amount of sugar in the juice.
Titration
Method of finding out the amount of a substance in a solution by gradually adding measured amounts of another substance that reacts in a known way. Used in viticulture to calculate acid levels in the grape.
Major factors to decide the harvest date
- Potential alcohol levels.
- Sugar levels by handheld refractometer (19° and 25° Brix are 11-15% abv)
- Aroma and tannin ripeness by taste.
- Weather forecast.
Pros/cons of machine-harvesting
✅ fast, cheap (1/3 of hand-harvesting), not many workers needed, harvest during the night, save the cost of eventually refrigeration (cool fruit), uniformity of ripeness
❌ less gentle, no whole bunch, cost (no for small-scale vineyards), unsuitable if different varieties in the same plot, no steep slopes, quality depend on the operator, availability of the machinery (if rental), major investment
Pros/cons of hand-harvesting
✅ high selection, steep slopes, irregular rows, mixed varieties in the same vineyard, avoiding of the grapes crushing and then the juice release by using small crates
❌ cost (in medium to large scale), availability of workers, only daylight hours
Second crop
Lateral shoots often produce inflorescences. It’s common on Pinot Noir. The ripening is different from the main shoots, so green harvesting to improve the ripeness uniformity.
Lag phase
Grape growth slows down for a few days before véraison.
