Ch. 1: The Vine

Question 1

Shoots

Answer 1

Grow in the spring from the buds of the previous year. They contain all of the structures that will form the canopy of the vine: buds, leaves, tendrils, lateral shoots, and inflorescences/grape bunches. Shoots transport water and nutrients (via solutes) between the different structures, as well as store carbohydrates.

Question 2

One-year-old wood

Answer 2

Shoots from the previous year that were not pruned, and which support the new shoots of the current year and compound buds that will break open next year. Depending on how the vine is pruned, it can be a cane or a spur. A can usually includes approx. 5-8 buds, while a spur will include 2-3.

Question 3

Permanent wood

Answer 3

Consists of wood that is older than one year old, and includes the trunk, and depending on pruning method, horizontal arms called cordons. Permanent wood supports other vine structures, stores carbohydrates and nutrients, and transports solutes and water between other parts of the vine.

Question 4

Roots

Answer 4

Roots function to anchor the vine into the soil, store carbohydrates, and uptake water and nutrients into the vine. They adapt to the soil structure and texture to maximize water and nutrient uptake, whether penetrating deep into the soil or spreading more towards the surface.

Vines are often grafted onto rootstocks that help them to adapt and thrive in their particular environment, including preventing disease and tolerating hazards such as frost and drought.

Question 5

Buds

Answer 5

Buds form on the vine at the intersection of the stem, and the leaf. They contain all of the structures of the vine that will develop into the green parts of the vine, including the buds, stems, tendrils, leaves, and inflorescences.

There are two types of buds: compound buds, which burst and form shoots in the upcoming season, and prompt buds, which burst in the current season and form lateral shoots, which can function as back-up shoots if vine damage occurs.

Question 6

The vine structure can be divided into 4 sections:

Answer 6

Shoots
One-year-old wood
Permanent wood
Roots

Question 7

What are the 5 major structures of shoots?

Answer 7

Buds
Leaves
Lateral Shoots
Tendrils
Inflorescences/grape bunches

These are collectively the canopy.

Question 8

Compound buds

Answer 8

Compound buds form on the vine at the intersection between the base of the leaf and stem. They will burst to form the shoots of the upcoming season. They contain primary buds, which are the main buds, and smaller, secondary and tertiary buds that will form if there is damage to the primary buds. If damaged, grape quality and yields for the upcoming season could be negatively affected.

Question 9

Prompt buds

Answer 9

Prompt buds burst to form lateral shoots in the current year’s harvest. They form as backup shoots, and can be used to replace primary shoots that become damaged. They form on the primary shoot that just developed from last year’s bud.

Question 10

Lateral shoots

Answer 10

Lateral shoots form from buds that burst on the primary shoots for the current year (prompt buds). They are smaller than the primary shoots and contain the same structures, including stems, leaves, tendrils, and buds. They function as backup shoots, in case the tip of the primary shoot get damaged, and allow the vine to continue to grow. They also provide additional sources of leaves for photosynthesis.

Lateral shoots need to be managed throughout the year to maintain the balance of the vine, and are often pruned in the Summer to remove bunches of grapes that have grown and will ripen unevenly from the primary shoot growths, and those that grow near the base of primary shoots which might shade the fruit too much.

Question 11

Tendrils

Answer 11

Tendrils are the green tips that form on shoots and wrap around permanent structures to support the vine as it grows. They help to keep the canopy in place when the vine is attached to trellises.

Question 12

Leaves

Answer 12

Leaves are the primary source of Photosynthesis for the vine, which leads to vine growth and metabolism. They absorb carbon dioxide and provide a wide surface area for sunlight to convert water and carbon dioxide into sugar.

Pores on the underside of the leaves (Stomata) release water vapor from the vine, and allow carbon dioxide to enter for photosynthesis. This, in turn, pulls water and nutrients up from the soil, a process called transpiration. If the vine is water stressed, the Stomata will close to conserve water, but that will also inhibit CO2 absorption, limiting Photosynthesis and vine growth.

Question 13

Transpiration

Answer 13

A process by which water vapor is released from the leaves of a vine via pores on the underside of the leaves called Stomata. This draws water and nutrients up into the leaves from the soil.

The rate of transpiration is higher in warmer climates and correlated with sugar accumulation. That’s why grapes in warm climates can accumulate too much sugar during ripening if not managed properly.

Question 14

Photosynthesis

Answer 14

The process by which plants convert CO2 and water to sugar with sunlight. The leaves are the main site for photosynthesis. The sugars are used for vine growth and metabolism.

The vine requires access to sunlight, water, warmth, and nutrients for Photosynthesis (CO2 is also required but is outside of the grape grower’s control).

Question 15

Inflorescences

Answer 15

Inflorescences are the structures that will eventually flower, bud, and develop into grape clusters. They form on the primary shoots in the Spring and early Summer, when temperatures maintain at least 50 degrees. In order to flower properly, warmth, sunlight, nutrients, and water are vital at this time in the cycle.

Question 16

Pulp

Answer 16

The pulp of a grape is composed of water, acids, sugar, and some aroma compounds and pre-cursors (aroma compounds that appear during fermentation and bottle age).

Question 17

Skin

Answer 17

Contains high concentrations of aroma compounds and precursors, tannins, and compounds. The amounts of tannins and colors in black grapes is significantly higher than in white grapes. In red wine, the skins are incorporated into the winemaking and impart the color and tannin levels in the final wine.

Question 18

Seeds

Answer 18

Seeds mature inside the grape, turning from yellow to brown. They contain oil, tannins, and the embryo, which can grow into the new plant.

Question 19

Cordons

Answer 19

Cordons are permanent wood on the vine that grow horizontally depending on how the vine is pruned. They support new shoot and canopy growth, store carbohydrates and nutrients, and transport water and solutes to other parts of the vine.

Question 20

Cuttings

Answer 20

Cuttings are a method of vine propagation. Sections of a shoot that are cut and can be planted to grow into a new vine. It is the most common method because many cuttings can be removed from the vine, so it’s efficient, and the vines can be grafted onto rootstock. They can also be treated by nurseries to prevent disease. This creates new plants that are genetically identical to the parent plant.

Question 21

Layering

Answer 21

Layering is a propagation method in which the cane of a vine is buried next to the vine with the tip exposed. The section that is buried takes root. Once the the roots are established, the cane linking the two vines is cut. Because this method uses the roots of the original vine, it cannot be grafted onto rootstock which may make it more vulnerable to disease and hazards depending on the vine species. This creates new plants that are genetically identical to the parent plant.

Question 22

Clone

Answer 22

A clone is a vine with the same genetic material as its parent, but due to random mutations, has slightly different characteristics than its parent vine. Wine growers will select the clone of a varietal base on its characteristics, the environment, and the style of wine they are aiming for.

Question 23

Clonal selection

Answer 23

The process of selecting vines with favorable characteristics and propagating them through cutting. This has led to different clones within a grape variety. For example, Pinot Noir is a variety with many clones suitable for the specific wine style desired.

Thick skinned clones with lower yields are better suited for high quality red wines, while larger, thinner skinned clones are better suited for sparkling production where high concentrations of color and tannins are not needed.

Question 24

Mass Selection

Answer 24

Cloning from a vineyard. The winemaker will select cuttings from vines in the vineyard which have performed well over several seasons, and consistently produce grapes with the desired characteristics.

Advantages are that it increases diversity of plant material in the vineyard, and potentially, qualities in the grapes and wine that are unique to that winegrower. This can be used to market the wine. Disadvantages are is that if the original vine is diseased, the disease will spread, and that the process is costly in time and labor.

Question 25

Cross fertilisation

Answer 25

When the pollen from one vine is inserted into the stigma of another vine. The seeds are then planted to create new grape varieties with the genetic material of both vines, and that have different characteristics from each other, like siblings.

If one of the new varieties has desired characteristics, it can be assessed over time to see if it would be valuable commercially. If so, it would need to be registered on the OIV catalogue.

OIV is the International Organization of Vine and Wine

Question 26

Crossing

Answer 26

A crossing is a grape variety in which both parents are from the same species. For example, Pinotage is an example of Pinot Noir and Cinsault. Most varietals are crossings.

Question 27

Hybrid

Answer 27

A hybrid is a grape variety of which each parent is from a different species. The best known is Vidal Blanc from Ugni Blanc (V.vinifera) and a member of the Seibel family (American).

Various hybrids were bred with the aim of combining the resistance non-V.vinifera with the quality of vinifera, and although the fruit was not is not considered as high quality as vinifera, the rootstocks are can be used for this purpose. , they are valuable for their rootstocks. though the results were not successful. However, hybrids are used for rootstock, which can combine attributes that allow vines to thrive in