DIPWEST D1 Flashcards
What are the major non vinifera grape species in viticulture?
Vitis Labrusca
Vitis Riparia
Vitis Berlandieri
Vitis Rupestris
What are the 4 main sections of the structure of the Vine?
The shoots
One year wood
Permanent wood
Roots
What is lignify?
Lignify is the process of green shoots becoming woody, rigid and brown as they transition into canes.
In shoots what are nodes and internodes?
Nodes are the small swellings in the nodes that other structures grow from. Internodes are the vine that grows between these
What are shoots and what are their main structural components?
Shoots are the green vine growth that grows from spring. These are made up of the
Tendrils
Lateral shoots
Inflorescences or grape bunches
Leaves
Buds
What is the Bud? What are the 2 major types?
Buds are the growths of new shoots that form between the leaf stalk and the stem. They contain all of the structures in minature required to become the new shoot.
The two major types are:
•Compound buds - (latent buds) form in one growing season and break open in the next (if not pruned). Compond buds typically contain a primary bud as well as a back up of a secondary and possibly tertiary buds that will only grow if the primary is damaged (eg spring frosts)
•Prompt Buds - form and break open in one season. These form on the primary shoot and will produce lateral shoots. These are back up buds that are natures insurance if the main shoot is damaged.
What are lateral shoots and what do they do?
Lateral shoots are grown from buds that form and grow in the same season. These second shoots allow for the growth of additional leaves for photosynthisis and allows for the plant to continue growing if the original shoot is damaged or eaten.
These additional grows may form inflorescenes (varietal dependent (Pinot Noir does)) that may bloom into a second later crop of grapes. These will have higher acid, lower sugar and unripe tannins, flavours and aromas. These can be pruned or discarded at picking but will be collected by machine picking and affect the overall balance of the wine
In the shoots what are the tendrils and what do they do?
The tendrils are the end of the vines responsible for attaching to a support structure(tressil or anything close in the wild).
These are not often soley trusted by growers and they will tie in canes and and shoots as necessery
Discuss the leaves of a vine. What are their main functions
Leaves are mainly responsible for photosynthisis and shading. In photosynthisis the stomata (pores) on the underside of the leaves open to diffuse water out and allow carbon dioxide in. As this happens transpiration draws water and nutrients from the soil. The stomata will partially close if the vine is water stressed. It will save water but slow photosynthisis
What are inflorescenes and what do they do?
Inflorescenes is the cluster of flowers on a stem that will become a grape bunch. Numbers per shoot depend on variety but usally sit between 1-3
What disadvantages do tight grape bunches have?
Tight grape bunches face increased fungal risk due to increased chance of grapes spliting and lower air flow between grapes.
What is the term used for grapes with red flesh? What is the major example?
Teinturier
Alicante Bouschet is the most popular example
What are the 3 major components of a grape?
Pulp - flesh - majority of the grapes weight and contains water, sugar, acid and some aroma compounds and precursors.
Skin - high concentration of aroma compounds and precursors, tannins and colour compounds
Seeds - contain oils, tannins and embryo that will grow into another vine. Often bitter and best to avoid breaking.
What is the name for the powdery wax coating that covers grapes? What is its point?
The Bloom. This is a naturally occouring part of the grape that works as a barrier against insects and bacteria
In the vine, what is one year wood and what is it used for?
One year wood refers to shoots from the previous season that were not pruned. Allowing them to lignify and become woody. These support the compound buds that will become the new shoots.
These may be either cane or spur trained
In the vine, what is the permanent wood and what does it do?
The permanent wood is any part older than 1 year. This includes the trunk and any cordons. They provide support, transport water and nutirents around the vine and store carbohydrates and nutrients.
In the vine, what are the roots and what do they do?
Roots are the anchors of the vine. They are responsible for the uptake of of water and nutrients from the root tips where they are actively growing, store carbohydrates and produce hormones that affect vine growth and grape ripening.
Most roots exist in the top 50cm of soil but have been found as low as 6m. This is affected by soil properties, irrigation, cultivation, type of rootstock.
In Vine propagation what is the 2 major techniques? Their strengths and weaknesses? What technique is not used?
Vines are propagated through either layering or cuttings.
•Cuttings refers to taking a section of vine shoot and planting it. This will begin growing a new plant. This techinque allows for many cuttings to be taken from a single plant and be propergated at once, allows for nurseires to treat for disease and for grafting onto alternative root stock.
Layering is the alternative, less popular technique of planting a still growing cane directly into the soil and then the head is positioned up. Once the cane has begun to sprout its own roots and becomes self sufficient the connection will be cut. This is used to replace damaged vines in the middle of vineyards quickly but does not allow for grafting and leaves the stock exposed to phyloxeria and will not have the qualities of the other chosen root stock.
Vines are not planted from seeds as these will not be genetically identical to the parents
What are clones? How do they occcur?
While layering and cutting produce plants that are genetically identical the random process of cell division allows for mutation. While most mutations have no effect on the plant. Some minor changes may be benifitial.
These beneficial mutations may be propergated by growers and nurseries to create genetically distinct clones of the same varietal.
In small or young regions this process may lead to a few or single clone dominating the market and leading to a relitively low complexity in total wine expression and a larger susceptibility to disease or pest infection.
What is mass selection? What is its benefits?
Mass selection is the historic technique for vine propargation. This involves taking cuttings from several of the vineyards best preforming plants with positive mutations and propargating them all to increase genetic diversity (resistance to disease and pests as well as increase in the diversity of flavours), and the marketing advatage of having a personal selection.
This is balanced by the costs of monitoring the vineyard and propergation costs as well as leaving the same weaknesses of a single vine to propargate through the vineyard
Who are the OIV?
The International organisation of wine and vine are a Dijon based intergovermental organisation that is the major database of all grape varietals (known as the OIV Catalogue).
Their scientific and technical work concerns vines, wine baesd beverages, table grapes, raisins and other wine based products
How are new grape varieties created?
New grape varietals are often produced from seeds. The polen of the stamen of one vine is introduced to the stigma of another. If the characters of this cross breeding is considered favourable then the vine maybe propagated through cuttings.
This can happen by random chance in nature or more frequently by botnanists working in laboratory conditions
What are the 7 stages of the vine growth cycle?
Dormancy
Budburst
Shoot and leaf growth
Flowering and fruit set
Grape development
Harvest
Leaf fall and return to dormancy
In the vine growth cycle, what is dormancy? When does it occor in both hemispheres and what are the threats the vine faces?
Dormancy is phase between leaf fall and bud burst where an average tempature of below 10 degrees C is too cold for a vine to grow. During this stage the vine survives on stored nutrients and carbohydrates in the roots and permanent wood.
Tempatures below -20C will threaten damage and below -25C will kill most V.Vinifra varieties.
This occors between Nov-March in NH and May-Sept in the SH
Consistant tempatures above 10C may cause an early bud burst that exposes the young vines to still harsh winter conditions
In the vine growth cycle, what is bud burst? When does it occor in both hemispheres and what factors affect the timing of this? What are the strengths and weaknesses these timings?
Bud burst is the spring time opening of the buds that will become the new growth for the year.
This occors in March-April in the NH and Sept-Oct in SH
Earlier bud bursts allow more ripening time but expose the vine to more winter hazards such as frosts.
Determining factors:
Air temperature: bud burst occors at roughly 10C. Continental regions with more distinctive seasonal changes may have more consistant bud burst and homoginised harvest. Maratime regions are more likely to have uneven harvests.
Soil temperatures: warmer soils encourage earlier bud burst. Dry free draining soils are more likely to warm quickly than heavy water storing soils.
Grape Varieties: some varieties bud at lower or higher temperatures. These are refered to as early budding or late budding varieties. Varieties budding time does not necessarily affect their ripening time (Grenache is early but late ripening.
Human factors: grape growing techniques can advance or delay bud burst. Delayed winter pruning can delay bud burst to avoid areas with frost problems
In vine develeopment, what is shoot and leaf growth, when does it occor(both hemispheres) and what dangers does the vine face?
Shoot and leaf growth is the development of the shoots and leaves during the late spring and early summer. The term vigour is used to describe the vegitative growth.
This occors in March-July (NH) and Sept-Jan (SH)
The begining of this growth is supported by the stored carbohydrates from last season (may be weakened by last seasons excessive high yields, water stress, infection, excessive leaf removal)
Once new leaves are able to grow, it is important that the vines are not water stressed as it may impare photosynthesis and shoot growth, limiting yield and flower development/fruit set.
In vine development, what is the determining factors of a buds fruitfulness?
Buds should be shaded from tempatures above 25C and avoid water stress and nutrient deficiency during development.
What is the major connection between fruit set and cool climate varietals?
Cool climate varietals are able to successfully polinate at far lower temaptures than other classic or hot climate varietals.
In vine development, what is flowering and fruit set, when does it happen, what are the dangers the vine faces?
Flowering and fruit set is the development of inflorescence and then their self polination.
This occors in May-June (NH) and Nov-Dec (SH)
Flowering takes place within 8 weeks of of bud burst and requires min 17C. Low tempatures can delay flowering.
Fruit set will typically happen for about 30% of flowers but can affect 0-60%. Pollen germination requires warmer tempatures and can be interupted or destroyed by cold tempatures, rain or winds. Irregular fruit set seriously affects yields. Hot, dry, windy areas leading to water stress can also lead to a negitive affect on yields.
What are the 2 most common forms of irregular fruit set and what are their causes and affects? What varietals are naturally susceptable?
Coulure and Millerandage
Coulure is a high percentage of flowers failing to develop into grapes. This is caused by a lack of carbohydrates which may be caused by cold and cloudy conditions or water stress limiting photosynthesis or vines diverting carbohydrates from flowers to shoot growth caused by highly fertilized soils or high vigour root stocks. Varietals Cab Sauv, Merlot, Malbec and Grenache
Millerandage is the development of a high number of seedless grapes. These grapes can still ripen but are smaller (lower yields) and may stay green and unripe. Can result from cold, wet and windy weather at fruit set. Susceptable varietals include Chardonnay and Merlot
What are the 4 major stages of grape development and what occors in each?
•Early growth - rapid expansion and acumulation of water weight, development of some aromas and precursors. Water stress can lead to smaller grapes or over water can lead to excessive berry size.
• Veraison - changing of colour of the skin of the grapes.
•Ripening - accumulation of sugars and decressing of malac acids in the grapes. Decreasing in methoxypyrazine compounds.
•Extra ripening - extended time on vine will result in the grapes no longer recieving any additional water or sugars and will begin to rasinate on the vine.
During ripening what are the major componets that are developed?
Sugars - a rapid accumulation of sugars happens at first and slows as the season progresses. This happens fastest in warm dry conditions. If conditions are too hot the sugars will develop before the aromas and tannins.
Decreasing of malac acids - the amount of tartaric acid is consistant but the malac acid concentration will decrease. Temps above 21C lead to rapid loss but below 15C will reduce this rate.
Decrease of Methoxypyrazines - decreasing of the aroma compound that is responsible for herbacious flavours.
Tannin development - tannins polymerise from simple compounds into longer more complex chains, becoming less bitter
Development of aroma and flavour - varietal dependent
How much sunshine is required for photosynthisis?
Roughly 1/3rd of full sunshine
What are anthocyanins and what are they responsible for?
Anthocyanins are the colour pigments in black grapes
