The Vine And Growing Environment

Question 1

What is petiole

Answer 1

Leaf stalk. Buds form between the leaf stalk and the stem

Question 2

4 main sections of the vine

Answer 2

The shoots, the one year old wood, permanent wood and the roots

Question 3

Structure of the shoots

Answer 3

Buds, leaves, tendrils, lateral shoots, inflorescences, grape bunches

Question 4

What are the nodes

Answer 4

The little swellings along the shoot, where the other structures are attached. The lengths in between nodes are called internodes.

Question 5

Types of buds

Answer 5

Compound woods also called latent buds: form in one growing season ( provided they are retained during winter) they produce shoots in the next growing season.

Prompt buds. Form and break open in the same growing season. They form on the primary shoot ( that has just grown from a compound bud) and produce a lateral shoot

Question 6

What are lateral shoots

Answer 6

The shoots grown from buds formed in the current year (prompt buds) they are smaller and thinner than the primary shoots

Question 7

What does second crop mean

Answer 7

Grapes that are grown from the inflorescences of lateral shoots. If harvested at the same time as the main crop, the bunches in the second crop will be higher in acidity, lower in sugar and may have unripe tannins and aromas/flavors in red grapes less color development. Can be removed during the growing season by green harvesting

Question 8

Function of the tendrils

Answer 8

Provide support. In viticulture, grape growers can use a trellis to position the vine canopy. The tendrils curl around trellis wires and keep the canopy in place.

Question 9

Inflorescences

Answer 9

Is a cluster of flowers on a stem, which becomes a bunch of grapes at fruit set. The number of inflorescences on each shoot can depend on the grape variety, but is usually between one and three

Question 10

Define one year old wood

Answer 10

It refers to the shoots from the previous growing season that were not removed at pruning.

The amount of one year old wood will depend on the pruning and training decisions made by the grape grower.

The one year old wood supports the compound buds that will break to release the shoots for the upcoming growing season.

Question 11

Permanent wood

Answer 11

Woody parts that are older than one year, including the trunk. The trunk and cordons provide support for other parts of the vine. The transport water and solutes to and from different parts of the vine and store carbohydrates and nutrients

Question 12

Roots definition

Answer 12

Important for anchoring the vine and also for the uptake of water and nutrients. The roots also store carbohydrates and produce hormones that have important functions within vine growth and grape ripening. In most cases vines are grafted onto a rootstock.

Question 13

Cutting method

Answer 13

A cutting is a section of a shoot that can be planted and will then grow as a new plant. It’s by far the most common propagation technique as many small cuttings can be taken from a vine and propagated at the same time. Importantly, it also permits the use of rootstock onto which the vine cutting can be grafted before it’s planted.

Question 14

Layering method

Answer 14

Is a method of filling gaps in a vineyard by using shoots from an established neighboring vine to produce a new vine. 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 section that is buried takes root and ice these roots are established, the cane linking the new growth, and this method is therefore not always suitable. No protection against phylloxera or other benefits that rootstock offers

Question 15

Clonal selection

Answer 15

Is the propagation by cutting of vines with favorable characteristics.

Question 16

Pinot noir clones

Answer 16

Pinot noir clone 115 has low yields of small grapes making it suited for high quality red wine.
Pinot noir 521 higher yields bigger grapes better for sparkling.

Question 17

Cross fertilization

Answer 17

The pollen from the stamens of the flowers of one vine is transferred to the stigma of the flowers of another vine and fertilization occurs.
The new vines will have different characteristics

Question 18

Clonal selection vs mass selection

Answer 18

Clonal selection is a relative recent practice that became common within the last 40-50 years. Before, grape growers would propagate their vines through a process of mass (selection massale); cutting vines from their own vineyards after years of monitoring and recording their performance. An advantage is that it increases the diversity of planting material in the vineyard and throughout the region, the vineyard owner uses their own unique planting material which can enhance fruit quality and/or yield. However, this is costly in terms of labour

Question 19

What is OIV catalogue

Answer 19

New grape varieties that have commercially value are added to this catalogue

Question 20

Dormancy

Answer 20

November-march in the northern hemisphere
May - September in the Southern Hemisphere.
Starts with the leaf fall in the autumn and ends with bud-burst in the spring

Question 21

Budburst

Answer 21

March - April northern hemisphere
September- October in the Southern Hemisphere.

Question 22

Temperature during budburst

Answer 22

Air temperature: compound buds begin to develop in the previous growing season. For buds to burst temperatures of around 10 degrees are needed.
Continental climates with marked differences in temperature between various seasons can be advantageous. The rapidly increasing temperatures in the spring mean that budburst can be relatively uniform and this has positive implications for the homogeneity of later stages in the growing season, potentially eventually leading to a crop of grapes with even ripeness.

Maritime climates with less contrast between winter and spring temperatures budburst can be less sunchronised. Furthermore, problems can occur when a few unusually mild winter days cause early budburst and cold days and frosts that follow can potentially harm the newly burst buds leading to lower yield.

Question 23

Grape varieties budburst temperature

Answer 23

Average temperature is 10.

Early budding: require relatively low temperatures: Chardonnay Pinot noir, merlot, Grenache.

Late budding: require higher temperatures: Sauvignon Blanc, Cabernet sauvignon, Syrah. Because the buds of late-budding need high temperatures they are less risk of spring frost.

Question 24

Shoot and leaf growth

Answer 24

March-July in northern hemisphere
September-January in Southern Hemisphere.

During spring and early summer, the shoots continue to grow and leaves and inflorescences mature. The fastest rate of growth generally between budburst and flowering.

Question 25

Define vigour

Answer 25

Vigour describe vegetative vine growth which includes the growth of the shoots, leaves and lateral shoots and has implications on the yield and ripening of the grapes. Hence, vines with high vigour can grow long shoots with large leaves and lots of lateral shoots. The vigour of the vine depends on a number of factores including the natural resources available to the vine ( temp, water, nutrients), the planting material and the presence of any disease.

Question 26

Risks, adverse conditions during soot and leaf growth

Answer 26

Low carbohydrate levels: caused by conditions in the previous growing season for example excessive leaf removal, water stress, mildew infections or excessive high yields in the previous growing season. Carbohydrates stored in the roots trunk and branches of the vine support initial growth, of these ch are low shoot growth can be negatively affected.

Water stress can limit photosynthesis and shoot growth. Nutrient uptake is also impaired in very dry soils. As vine grows, so does the vine’s need for nutrients (nitrogen, potassium and phosphorus).

Stunted shoot growth can lead to small, weak shoots, a reduction in leaf number or smaller leaves, inflorescences that do not flower properly and/or grape bunches that do not ripen fully. This can lead to poor quality and lower yields.

Question 27

Flowering and fruit set

Answer 27

May-June in the northern hemisphere
November-December in the Southern Hemisphere.

New buds develop at the base of the leaf stalk(petiole). Prompt buds will burst within the growing season producing new shoots called lateral shoots. Compound buds will remain dormant until the following spring and provide the shoots for next year. The conditions during this part of the growing season can have substantial influence on the next year’s yield.

The yield and quality of grapes in the current growing season are strongly influenced by the process of flowering and fruit set

Question 28

Flowering

Answer 28

Flowering describes the opening of the individual flowers within tan inflorescence. Within this process, the pollen-laden stamens (consisting of an anther and filament) are exposed. The pollen grains are shed and land on the moistened stigma surface, a process called pollination. Here they germinate, with each pollen grain producing a pollen tube. These pollen tubes penetrate the stigma and the ovule ( the female reproductive cells) in the ovary. The pollen tube delivers the sperm cells that fertilize the eggs in the ovule. This leads to the formation of a grape berry. The fertilized ovules form seeds, with up to four per grape. The wall of the ovary enlarges to form the skin and pulp of the grape

Question 29

Conditions for successful fruit set

Answer 29

Typicall 30% of the flowers will become grapes, but this can range from zero to 60%. Pollen germination requires warm temperatures (26-32) polle. Tube growth is negatively affected by cold, rainy and/or windy conditions and this can result in irregular fruit set and is a key cause of poor yields in cool climates. Hot, dry and windy conditions leading to water stress can also have a negative effect again leading to reduced yields.

Question 30

Coloure

Answer 30

Coloure is a condition of the grape bunch in which fruit set has failed for a high proportion of flowers. This occurs when ovule fertilisation is unsuccessful and therefore no grape develops. Excessive coloure can reduce yield dramatically. It is caused by an imbalance in CH levels. This can result from low rates of photosynthesis, which may be caused by cold, cloudy conditions or hot, arid conditions with high water stress. It can also result from vigorous shoot growth diverting carbohydrates from inflorescence. Very fertile soils, heavy application of fertilizers and vigorous rootstock can all cause strong shoot growth and therefore lead to coloure.

Question 31

Millerandage

Answer 31

A condition of the grape bunch in which there is a high proportion of seedless grapes. The grapes are smaller therefore reducing the volume of wine produced. Some seedless grapes stay small, green and unripe negative for wine quality. Millerandage can result from cold, wet, windy weather at fruit set with some varieties such as Chardonnay and merlot being more susceptible than others.

Question 32

Grape development

Answer 32

June- September northern hemisphere
December-April Southern Hemisphere.

Question 33

Grape development. Stage 1: early grape growth

Answer 33

This stage starts soon after fruit set. Hard green grapes start to grow in size and tartaric and malic acids accumulate. Some aroma compound and aroma precursors also develop, such as methoxypyrazines. Methoxipirazines contribute to herbaceous aromas in wine such as Sauvignon Blanc, Cabernet Sauvignon, Cabernet Franc.

Tannins accumulate and are very bitter at this time. Sunshine on the grapes promotes tannin accumulation. Sugar levels are low throughout this stage. Water flow into the grape is high at this stage and it is mainly transported to the grape by the xylem.

Too much water and nitrogen can prolong this stage, as these factors encourage shoot growth in preference to grape ripening. This causes delay on the onset of the ripening stage and could mean that there is not sufficient time for ripening before the weather becomes cooler and the grapes need to be harvested.

Shoot growth continues throughout this stage, but usually more slowly than earlier in the growing season.

Question 34

Veraison

Answer 34

Grape growth slows down for a few days often called the lag phase. The grape cell walls become more stretchy and supple, green coloure chlorophyll in skin cells is broken down and grapes of black varieties start to become red in colour due to the synthesis of compounds called anthocyanins

Question 35

Ripening

Answer 35

This is arguably the most important vine process in determining final grape quality. Shoot growth should have slowed down substantially by this time. During this stage the cells in the grape expand rapidly, sugar and water accumulate and acid levels fall. Tannis, colour and a number of aroma precursors and aroma compounds develop. Harvest usually marks the end of this stage and tends to occur August- September in the northern hemisphere or February to April in the southern hem.

Question 36

Why grapes in warmer climates have higher sugar content

Answer 36

During ripening water flow via the xylem slows down and a sugar solution is transported by the phloem. The movement of the sugar solution from the phloem into the grape, and hence the sugar accumulation within the grape is correlated to the rate of grape transpiration. In warm conditions, this accumulation can be too rapid and reach high levels before aromas/flavors and tannins have developed fully.

Question 37

How acidity changes in the grape during ripening

Answer 37

The total amount of tartaric acid does not change, the concentration falls during ripening due to dilution as sugar and water accumulate in the grape.

Malic acid can be metabolised in respiration during the ripening stage. Respiration is slower at cool temperatures than warm ones and this is why wines from cooler climates tend to have higher natural acidity. Temperatures above 21 can lead to a rapid loss of acidity, whereas mean temperatures below 15 can reduce acid loss to a point that acidity levels in the must are too high. Cool night time temperatures also mean that less malic acid is lost during respiration. This is why areas with high diurnal range can produce wines with higher acidity.

Question 38

Extra ripening process

Answer 38

If the left are left on the vine, they start to shrivel. No more sugar or water are imported to the grape by the phloem at this stage, but water loss in the grape through grape transpiration means that sugars are concentrated. Extra-ripe aromas can also develop in this stage. This may be desirable in some styles of wine, but not on others. Grape shriveling is most likely in hot, sunny, dry climates.

Question 39

Effect of sunlight

Answer 39

The vine needs sunlight for photosynthesis, which is needed for vine growth and early grape growth and ripening. However, full sunshine is not essential, and generally the amount of light only becomes the limiting factor to the rate of photosynthesis of light levels drop below one third of full sunshine. Hence, fog can slow photosynthesis, but an average cloudy day will not.

Grape exposure to sunshine has a number of effects, including enhancing the development of anthocyanins in black grapes and reducing levels of methopyrazines. Sunshine on the grapes leads to a greater accumulation of tannins pre-veraison and promotes tannin polymerisation after veraison, which results in a reduction in bitterness. It is also associated with increased levels of some favorable aroma precursor and aroma compounds. Sunshine also warms the grapes and because of this, increases the rate at which malic acid is used up in grape respiration, leading to lower acidity levels.

Prolonged periods or sunshine and hot temperatures can lead to sunburn on sun-exposed grapes, which has a negative effect on grape quality and yields. In climates that are warm or hot and or very sunny, some shading of the fruit is usually beneficial. The grape grower may ensure the grapes are protected with one thin layer of leaves, so that the bunches receive dappled sunshine.

Question 40

Latitude effect in temperature and sunshine intensity

Answer 40

Regions at lower latitudes will receive more solar radiation per annum than regions at higher latitudes.
Regions near the equator also receive more intense solar radiation than those near the poles.

Solar radiation is adaorbed and scattered as it travels through the Earth’s atmosphere, decreasing its intensity. The curvature of the earth means that nearer the poles solar radiation must travel through a larger section of atmosphere to reach the earth’s surface.
It also means that the radiation hits the Earth at a low angle, so the radiation is spread over a larger area. By contrast, at the equator the radiation travels through a smaller section of atmosphere and hits the earth surface at a larger angle, so that solar radiation here is more powerful. This means that if all other factors are similar, temperatures will be higher at lower latitudes than those at higher latitudes. This means, that grapes grow at lower latitudes can have higher levels of sugar, lower levels of acidity, riper aromas and in black grapes, higher but riper tannins and more colour intensity than those at higher latitudes

Question 41

Latitud and hours of solar radiation

Answer 41

The numbers of hours of solar radiation through different times in the year is also determined by latitude. Low latitude regions receive similar daylight hours ( and hence heat and sunlight) throughout all season of the year. High latitude regions have longer daylight hours and shorter daylight hours in winter. This permits a longer duration of time over which photosynthesis can take place in the growing season, this can be useful in helping the vine to produce enough sugar for ripening grapes.

Question 42

Effect of Altitude in temperature and solar radiation

Answer 42

Temperature falls by 0.6c over every 100m. High altitude sites can therefore be favourable in areas of low latitude that would otherwise be too hot. Ex salta, Argentina. 3000m above sea level. By comparison, many of the best vineyard sites in high latitude areas, such as burgundy or loire valley, are at relative low altitudes, as otherwise temperatures would be too low for sufficient ripening.

Sunshine is more intense at high altitude than low altitude because solar radiation travels less through less atmosphere before it reaches these sites. Same with ultraviolet radiation. This promotes anthocyanins and tannin synthesis

Question 43

Effect of altitude in diurnal range

Answer 43

High altitude sites often have a high diurnal range.
The ground absorbs energy from solar radiation during the day and releases during the night. At lower altitudes the air in the atmosphere (water vapor) absorbed some of this energy, meaning some heat is retained at night. At high altitudes the air is thinner and holds less moisture and therefore heat escapes. In warm climates, this is beneficial for grape ripening.

Question 44

Aspect

Answer 44

Aspect is the direction vineyards are planted on slopes.

Vineyards that face the sun throughout most of the day will receive more solar radiation than those facing opposite direction.

Question 45

Importance of aspect

Answer 45

The importance of aspect and the steepness of the slope increases at high latitudes. This is because solar radiation hits the earth at a low angle at high latitudes, the slopes increases the angle (nearer to perpendicular) at which the

Question 46

El Niño southern oscillation

Answer 46

Is a climatic cycle in the Pacific Ocean that had a significant effect on weather patterns. It has two opposite phases. El Niño and La Niña.

Question 47

El Niño

Answer 47

Starts when warm water in the western Pacific Ocean moves eastwards along the equator towards the Caribbean. The eastern Pacific Ocean becomes warmer than average and this tends to cause high levels of rainfall and risk oh hurricanes in South America and California. Hurricanes can be destructive and rainfall can disrupt pollination and fruit set and lead to excessive water availability, which can increase vegetative growth and hinder ripening.

El Niño brings warmer than average temperature and dried conditions to the more northerly states of Washington and Oregon. On the western side of the Pacific Ocean in Australia, tends to cause warmer temperatures and drought conditions, which can cause extreme vine stresses and damage.

Question 48

La Niña

Answer 48

Caused when the eastern Pacific Ocean is cooler than average. Cooler and wetter conditions in Washington and Oregon and Australia but warmer drier conditions in California and South America.

Question 49

Transpiration

Answer 49

Water vapour diffuses out of the stomata (tiny pores) on the underside of the vine leaves. The loss of water from the cells in the leaf causes water to be pulled upwards from the soil, through the roots and the above ground parts of the vine. This is called transpiration.

Question 50

Where there is lack of rainfall during growing season

Answer 50

Argentina, California, South Africa and Australia. Irrigation is needed for viticulture to be possible.

Question 51

When water stress is good

Answer 51

Before veraison is beneficial as it inhibits further vegetative growth.

If water is too easily available into late spring and early summer, vegetative growth is promotes and prolonged into the period of grape ripening. This acts as a competitive source for the vine’s sugars, which can delay and compromise ripening.

Question 52

Define climate

Answer 52

Is the annual pattern of temperature, sunlight, rainfall, humidity and wind averaged out over several years (usually 30 years). The climate does not change from one year to the next, although it can alter over a period of decades.

To date most climate classifications have focused on patterns of temperature (often considered the most important influence on the vine cycle) and sometimes rainfall

Question 53

What is GDD

Answer 53

Growing degree days. Model of heat summation during the growing season. Created by Amerine and Winkler in 1944. It was originally intended for the vineyard regions of California.
To calculate it substract 10 or 50 (F) to the average growing temperature is a month.
Multiply by the days of the month.
Make the same calculation of each month and add together the totals without include negative values.

Question 54

What is soil

Answer 54

Soil is the upper layer of the earth and it’s typically made up of geological sediment ( solid matter sand, pebbles, rocks) that has been moved and deposited in a new location. Organic remains in the form of humus and the pores in between the sediment that contain water and air. Geological sediment comes from the weathering of bedrock ( the solid rock below the soil).

Question 55

Texture of the soil.

Answer 55

The texture describes the proportion of the mineral particles of sand, silt and clay.
Soils with high proportion of clay are said to be finely textures. Clay particles are very small, and because of this have a large surface area compared to their volume, so they are very effective at holding water and nutrients.
Sand particles are relatively large and have a small surface area compared to the volume ( finish)

Question 56

What is a bud

Answer 56

Buds form between the stalk (petiole) and the stem. As they mature they contain all the structures in miniature that will become green parts of the vine, including the stem, buds, tendrils, leaves and often inflorescences. Two main types compound buds and prompt buds

Question 57

Vine leaves

Answer 57

The leaves are the main site of photosynthesis in the vine. The sugars produced in photosynthesis are used for vine growth and metabolism. Stomata (pores) open on the underside of the leaves, letting water diffuse out and carbon dioxide for photosynthesis to enter. As water diffuses from the leaf, a process called transpiration draws water and nutrients from the soil up through the vine to the leaves. These stomata partially close if the vine is water stressed. This can help conserve water, but limits photosynthesis by preventing carbon dioxide from entering the vine

Question 58

Why late ripen varieties are good in hot climates

Answer 58

Early ripen varieties in hot climates would gain sugar and lose acidity too rapidly, resulting in unbalanced wines