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Flashcards in The Growing Environment Deck (127):
1

Below what temperature does a vine go dormant?

10 ° C

2

Define climate.

The annual weather pattern of an area averaged over several years.

3

Define "Cool Climate" and give examples.

Regions with an avg temp during the growing season of below 16˚ C, in which early ripening varieties (Chard, PN) will just ripen 

Ex.: Champagne, the Mosel, Southern England, Anderson Valley, Tasmania, parts of Carneros.

4

Define "Moderate Climate" and give examples.

  • Regions with an avg. temp. during the growing season btwn 16.5 - 18.5˚ C.
  • Suited to the production of med bodied wines from intermediate ripening varieties such as C. Sauvignon, Merlot, and Sangiovese.
  • Ex.: Bordeaux, Northern Rhone, Rioja, most of Piemonte and Tuscany. Also Coonawarra, Marlborough, and the more moderate parts of Napa and Sonoma.

5

Define "Warm Climate" and give examples.

Regions with an average mean temperature during the growing season between 18.5 - 21˚ C. These are suited to heat loving varieties such as Ruby Cabernet, Mourvedre, and Grenache. Often, fortified wines such as Port and Liqueur Muscat are produced Examples include the Southern Rhone, Jerez, McLaren Vale, Paarl, and the Douro.

6

What is "Continentality"?

Continentality is the difference between the average mean temperature of the hottest month and the coldest month. Where the difference is large, climates are continental. When they are small, climates are maritime.

7

Define "Maritime Climate" and give examples.

Characterized by low annual range of temperatures combined with relatively high levels of rainfall. The ripening period is reasonably long with moderate temperatures. These are usually found near large bodies of water. Rainfall during the growing season tends to be higher than either Mediterranean or Continental climates, and this brings extra cloud cover: this coupled with moderate temperatures make maritime climates ideal for the production of medium bodied wines with moderate alcohol levels. Examples include, Muscadet, Bordeaux, Rias Baixas, Vinho Verde, Southern England, and the eastern coast of New Zealand.

8

Define "Mediterranean Climate" and give examples.

Characterized by low annual range of temperatures but with dry summers and wet winters. The dry, sunny growing season is suitable for a wide range of wine styles -- but in particular, full bodied and richly textured reds with ripe tannins. Examples include those around the mediterranean, but also most of Chile, most of South Eastern Australia, parts of the United States' West Coast, and the Cape in South Africa.

9

Define "Continental Climate" and give examples.

Characterized by wide annual range of temperatures with hot summers and cold winters. Generally found inland away from the moderating effects of the sea. In regions far from the equator this results in warm but short summers. The combo of long day length and continentality makes viticulture viable in the northern regions of Germany, Champagne, and British Columbia. Requires the use of early-ripening varieties. Drier than Maritime = less risk of rot at harvest, so late harvesting is less of a risk. Examples include Alsace, Wachau, Burgundy, Mendoza, Central Spain.

10

Define "Tropical Climate" and give examples.

Minimal annual temperature variation so seasons tend to be defined not by temperature but by other factors (i.e. rainfall). Because the vine needs clear temperature signals for its dormant period and growth cycles, tropical and sub-trobical climates are considered unsuitable for high quality viticulture -- even in locations where temperature is moderated by altitude or proximity to cool oceans. Examples include Brazil and India but the lack of winters can mean a vine crops more than once a year and with no dormant period with which to rest -- Because of this, vines in these climates have a shorter lifespan.

11

Explain the role of Glucose to the vine.

Glucose is the building block of the vine: Sun, Water, and CO2 are photosynthesized to make it. Glucose molecules are combined to make larger carbohydrates, including cellulose which helps build the roots, trunk, shoots, leaves, and fruit. It is also the basic building block for the creation of tannin, acids, and flavor molecules within the grape.

12

At what temperature does vine growth peak?

Typically between 22 - 25˚C. Above this, the vines metabolic needs increase faster than its ability to photosynthesize sugars so growth slows.

13

Explain the role of Glucose to the vine.

Glucose is the building block of the vine: Sun, Water, and CO2 are photosynthesized to make it. Glucose molecules are combined to make larger carbohydrates, including cellulose which helps build the roots, trunk, shoots, leaves, and fruit. It is also the basic building block for the creation of tannin, acids, and flavor molecules within the grape.

14

At what temperature does vine growth peak?

Typically between 22 - 25˚C. Above this, the vines metabolic needs increase faster than its ability to photosynthesize sugars so growth slows.

15

Why are western facing vineyards disadvantageous?

Vineyards facing west, towards the setting sun, face a triple disadvantage: They do not catch the sun as it rises in the morning as east facing vineyards do, their sunlight will be scattered by dust that has been lifted by warming air during the day; and they tend to face damper cooler prevailing weather conditions.

16

What are some advantages to a sloped vineyard?

--- Sunlight reduces in intensity as he angle at which it hits the ground reduces from 90˚ to 0˚ -- Partly due to the light beams having to travel through a greater thickness of atmosphere to get to the ground (and thus more energy being absorbed), but mostly due to the fact that the available sunlight is dispersed over a greater area of land. --- Soils on slopes tend to be poorer, coarsely textured, and better drained, moderating vine vigor. --- If the vineyard is on a slope, the cold and relatively dense air moves downhill. The sinking cold air displaces warmer, less dense air to higher levels producing warm thermal layers on the slope. Above the warm layers air temperature again drops, which is why, for example, the best vineyards of the Cote d'Or run along the middle band of the slope. This air movement on slopes is especially valued in cooler climates as the air movement deters frost and offers slightly improved ripening potential.

17

What are some disadvantages to a sloped vineyard?

--- Increased risk of Erosion, although other factors such as rain intensity as well as soil texture and structure play a major part. --- Higher costs incurred to harvest than flat ones. Must be worked by hand.

18

What are the advantages of "Isolated Hills" and give examples?

Examples: The hill of Corton, Somló, and Montagne de Reims. These are ideal vineyard sites because there are no big currents of colder air flowing down from the main hills.

19

What are some advantages and disadvantages to vineyards near bodies of water?

Advantages: -- Reflects sun's rays -- Provides water for irrigation -- Reduces risk of ground frost -- Can provide morning mists to encourage the development of 'Noble Rot,' which may be desirable. Disadvantages: -- Increases humidity of a sight, which increases the risk of fungal disease, in particular downy mildew.

20

What are some advantages and disadvantages to vineyards near bodies of forests?

Advantages: -- Act as windbreaks -- Store heat in cold weather -- Increase humidity Disadvantages: -- Harbor large flocks of birds which feed on and damage grapes.

21

Name some effects of a thick vigourous canopy.

-- Reduces flower initiation and berry set due to shading. -- Results in higher levels of acid retention due to cooling. -- Reduces sugar accumulation due to an increase in humidity and shade from the vigourous canopy. -- Encourages competition between vigorously growing shoot tips and berries for sugar, which reduces berries' ability to fully ripen.

22

How does temperature affect 1) the yield of a vineyard 2) The quality of a winegrape crop?

1) -- Vigor of the vines -- # and size of flower cluster -- success of the setting of these into berries. 2) -- level of yield obtained -- accumulation of sugars and the reduction of acidity in the berry. -- the development of wine aromas and their precursors.

23

At what temperature will vines be affected by freeze injury?

Begins at -15˚C, is serious at -20˚C, and can be fatal at -25˚C -- Unless the vine is insulated by snow or earth pushed up around it. A site will usually be considered unsuitable for viticulture if its temperature falls below -20˚C more than once every 20 years or if the mean temperature for the coldest month is less than -1˚C.

24

How is the Amerine and Winkler heat summation (1944) calculated?

Mean temperature of the month - 10˚C (Min temp for vine growth) x number of days in the month --> Monthly sums are totaled for the 7 months of the growing season. Category 1 (2200) -- Bulk wines, table and drying grapes.

25

Above what temperature does vine growth slow?

30˚C

26

What are some effects of sunlight on vine growth?

-- Direct effect on the rate of photosynthesis -- Direct effect on bud viability, initiation of vine flowers, berry ripening, and cane maturation. -- Indirect effect due to heat accumulation.

27

How many hours of sunshine is required for Vitis vinifera to ripen ripe fruit?

1250. Additionally, the amount of available sunshine will decrease by up to 10% if the vineyard is located near a large town or city, due to pollution effects.

28

How does altitude influence temperature?

The mean annual temperature decreases by .6˚C with every 100 meter rise above sea level.

29

What factors influence soil fertility?

-- Soil texture -- Soil structure -- Organic matter content -- Mineral content -- Availability of air and water -- Level of acidity/alkalinity

30

What is soil texture?

The size of the particles that make up soil, and their proportions relative to one another. They are graded according to their diameter in mm: 0 < Clay < 0.002 < Silt < 0.02 < Fine Sand < .2 < Sand < 2 < Gravel < 2+ Most soils contain a mixture or particle sizes. Soil texture can be assessed by touch.

31

What are some disadvantages to clay soils?

Clay soils hold more minerals, as their particles are negatively charged, but they have several disadvantages. --- They take longer to heat in the spring and tend to be colder all year round because they hold more water. --- They swell when they absorb water, and shrink when they dry. This can cause severe cracking through which water is quickly lost. This cracking also can damage root systems. --- As clay becomes wet, it becomes very sticky. --- When wet clay soils are worked, their structure deteriorates.

32

What is loam?

The texture of soil with ideal fertility. It is a mixture of clay, silt, and sand. It combines the nutrient holding capacities of clay, with the good drainage capabilities of sand.

33

What is limestone? Where is it found?

Sedimentary rock formed from the deposition of shells and skeletons of marine animals. It consists largely of calcium carbonate, is usually alkaline and free draining. Many classic wine regions have limestone soils including central and eastern Loire, Piemonte, most of Burgundy, northern Spain, and the Limestone Coast in South Australia.

34

What is chalk? Where is it found?

Chalk is formed in the same way as limestone but has a lower density and so is even more free draining. Very pure chalk soils are found in Champagne and Jerez.

35

What are 3 sedimentary rocks important to vine growing other than limestone and chalk?

Dolomite: Similar to limestone but with high levels of magnesium. Sandstone: Composed of compressed sand (Quartz) particles. Shale: Sedimentary rock that was originally composed of clay and is quite soft.

36

What is slate?

Shale that has been altered through high pressures and temperatures (Metamorphosis). Harder and less porous than shale. Found in the Mosel, for starters.

37

What is granite?

An igneous rock. Extremely hard and dense but still free draining. Common in Baden and the Northern Rhone.

38

What is soil structure?

The way in which soil particles form lumps or crumbs. It affects the availability of water and air to plants and the ability of fine feeding roots to penetrate the soil and exploit the essential plant nutrient supply. Soil structure is influenced by: Organic Matter, earthworms and other organisms, wetting and drying, freezing and thawing, presence of plant roots, cultivation and other soil management practices, texture, drainage, compaction.

39

How is good soil structure measured? What are the pitfalls of poor soil structure?

Where the particles form stable clumps of 1-5mm in diameter. For this to happen there has to be 3-10% organic matter. Poor soil structure can lead to: -- Capping/Crusting: When soil surface hardens. -- Puddling: where rainwater sits on surface of crust and causes extensive erosion. -- Sieving: where clay particles are carried along with water draining through the soil and deposited lower down, sometimes forming a layer that prevents the aeration and drainage of the soil.

40

What is humus? Benefits?

Organic matter in soil broken down by soil organisms, composed of plant and animal remains and animal excreta that has decomposed. It is composed of -- Sugars, starches, cellulose, and nitrogenous compounds. -- Lignin and mineral matter. Benefits: -- maintenance of soil structure, as it helps bind particles. -- retention of available nutrients, as it helps bind particles -- a high water holding capacity makes more water available to plants. -- low plasticity and cohesion, which makes soil management easier. -- there is a gradual release of available nutrients as the humus is slowly mineralized. -- darkening of color, which increases soils ability to absorb heat.

41

What are soil layers?

As soil is formed, the different structural and textural types will form layers, which can be investigated by digging a soil profile. A soil profile reveals the depth of these layers, and if there are any drainage or root barriers in the soil which will prevent its exploration by plant roots.

42

How many mm of water are required to satisfy a vines needs?

500. Even more in hot conditions.

43

Describe some ways in which soil aeration is helpful.

-- Provides oxygen to aerobic organisms and surprises the growth of harmful anaerobic ones. -- Provides roots with essential oxygen for respiration and growth. -- Removes carbon dioxide and other waste gases formed by the breakdown of organic matter and by plant roots.

44

Explain the role of nitrogen to the vine.

-- Second only to water in importance to plant growth. -- A major constituent of plant cell proteins, nucleic acids, chlorophyll, and hormones. -- Encourages vigorous shoot growth which can shade fruit and inhibit ripening. Fertile soils have large amounts of available nitrogen.

45

Explain the role of phosphorus to the vine.

-- Key element in energy fixation. -- Encourages berry ripening and root growth.

46

Explain the role of potassium to the vine.

-- Regulates the flow of water and sugar in the plant. -- Encourages berry ripening.

47

Explain the role of calcium to the vine.

-- Regulates cell acidity. -- Important component of cell walls.

48

Explain the role of sulfur to the vine.

-- Essential constituent of some amino acids and enzymes.

49

Explain the role of magnesium to the vine.

-- Essential component of chlorophyll. -- Regulates internal acidity and sugar metabolism. -- Encourages ripening.

50

Name some trace elements that are important to the vine in small amounts.

Boron, Manganese, Copper, Iron, Molybdenum, Zinc, Cobalt, Chlorine, Silicon.

51

What is the pH range for an acidic soil?

4-6.9 Acidity has a considerable influence on nutrient availability and soil organisms. Different crops have different pH tolerances: Grapevines cannot tolerate soil pH below 5 because in these soils, aluminum becomes available to the plants roots and poisons the plant. Soils tend to become more acidic with cultivation due to the release of organic acids on the breakdown of organic material.

52

What is the pH range for an alkaline soil?

7.1-8.5 Limestone soils tend to have high pH. This inhibits uptake of iron and other micronutrients, increasing the risk of chlorosis.

53

What are shoots called once they brown and "go woody" in autumn?

Canes.

54

Explain the role of leaves to the vine.

Principally responsible for photosynthesis (Leaf top) and transpiration (leaf bottom). They also can shade grapes.

55

What is a petiole?

Leaf stalks. Petiole analysis is one of the best ways of determining the nutrient requirements of the vine.

56

What are Inflorescences?

Bunches of small berry flowers grouped together.

57

What are tendrils?

Flower clusters are formed in lower half of the shoot: further up, these are replaced by tendrils that search out trellis wires in order to allow the shoots to stay upright and achieve the maximum amount of sun.

58

What is floral initiation?

Occurs during vine flowering. In the dormant buds this process develops embryonic flowers which the maximum number of bunches per shoot the following year. Successful floral initiation depends on temperature and sunlight exposure and there being sufficient carbohydrate reserves in the wood.

59

What is Coulure?

The failure of berries to set.

60

At what age is the vine most vigorous?

Between 7-20 years.

61

Which vine species have poor calcium tolerance, which one has a high calcium tolerance? Why is this significant?

V. riparia and V. rupestris have poor calcium tolerance whereas V. berlandieri has a high tolerance but doesn't graft or root well from cuttings. Because of this, nurseries have compiled many different hybrids of berlandieri with either rupestris or riparia, to get the best of both worlds for the rootstock selections.

62

What is "Layering"?

When vine canes are buried into the ground then separated from the parent plant once they've established old roots. Not viable where phylloxera presents a risk. Used in Argentina, and famously, in Bollinger's Vielles Vignes Françaises.'

63

What is bench grafting?

Carried out indoors in late winter/early spring. Field grafting has been abandoned largely in favor of this.

64

What is Vitis vinifera sativa?

The cultivated vine wish 5,000-10,000 wine-producing varietals. Includes all the classics. Selected to be hermaphoditic for good fruit set (with few exceptions) and for relatively large fruit.

65

What is Vitis vinifera silvestris?

Ancestors of all modern grapevines. Not usually hermaphroditic. Wild european vines. Same species as vinifera, but mostly wiped out by phylloxera.

66

What is Vitis riparia?

Grape species found mainly wild on river banks and alluvial soils in central-eastern parts of North America. Used principally as a rootstock: Riparia rootstocks are low in vigour and in surface rooting and encourage early ripening. They have good phylloxera resistance. However, they suffer from iron deficiency (chlorosis), in chalky soils. They are often used to control vigor on highly fertile soils.

67

What is Vitis rupestris?

Grape species found wild on light soils in southern-central North America. Used principally as a rootstock: Rupestris rootstocks are vigorous, with a deep rooting system. They have good resistance to phylloxera, but are very susceptible to chlorosis. Good choice of rootstock for poor soils with limited water availability.

68

What is Vitis berlandieri?

Grape species found wild on chalky slopes in southern USA and Mexico. Vigorous and deep rooting and has high resistance to chlorosis. Its cuttings have a very poor ability to root so it is often hybridized with riparia or rupestris in order to produce lime resistant rootstocks that graft and root easily with different levels of vigour.

69

What is Muscat Ottonel?

A crossing of Muscat de Saumur and Chasselas. It is used for dry and off-dry fruity whites in Alsace and Central Europe. It is less aromatic than the other Muscat varieties.

70

Name an intrinsic fault of the Syrah variety.

Prone to develop reductive (Mercaptan) flavors.

71

Name some intrinsic faults of the Merlot variety.

-- Can be bland and lack structure. -- Early budding so prone to spring frosts. -- Prone to Coulure.

72

What is Ruby Cabernet

Carignan x Cabernet Sauvignon. Positives: Can withstand hot weather Drought resistant High yielding Negatives: Poor fruit set and vulnerable to powdery mildew Wines tend to be flat and lack structure

73

What are the symptoms of phylloxera infestation?

-- The vines die of drought in patches that increase in size year by year. -- The roots of infected vines are covered with insects, which appear as oval yellow-brown dots surrounded by lemon-yellow eggs. -- There are nodosities (whitish or yellowish growths) near the root tip and tuberosities (swellings) on the older roots. -- There are pale green leaf galls on the under surface of the leaves.

74

Explain rootstock selection in regard to vine vigor.

Rupestris based rootstocks will have a higher level of vigor, while riparia based rootstocks have lower. Weak vigour rootstocks are generally selected for cool climates as they encourage earlier ripening and in quality wine production can help control yield.

75

What are some aspects of rootstock, Riparia Gloire de Montpellier?

-- Riparia parentage -- Great Phylloxera resistance -- Low lime tolerance -- Low vigour -- Low resistance to drought -- Prefers moist soils -- Sensitive to compact soils -- Suitable for the production of quality wines -- Prefers cool, humid, and fertile soils

76

What are some aspects of rootstock, Rupestris du Lot?

-- Rupestris parentage -- Good Phylloxera resistance. -- Sensitive to compact soils -- Sensitive to coulure -- Low lime tolerance -- High vigor -- Prefers deep, poor, and healthy soils

77

What are some aspects of rootstock, AXR1?

-- Vinifera x Rupestris -- Med+ Vigour -- Versatile in its preference for soil types -- High lime tolerance -- Easy to graft -- Yields high quality fruit -- Low Phylloxera tolerance -- formerly widely used in CA.

78

What are some aspects of Riparia x Rupestris based rootstocks? Examples?

Halfway between surface and deep rooting. Average vigour, grafts well, good affinity with scions. Good resistance to phylloxera, but poor resistance to chlorosis and drought. 3309 C: -- Prefers cool, fertile, and permeable soils. -- Fruits well. Widely used in France, Germany, Switzerland. -- Particularly recommended for acidic soils. 101-14: -- Prefers cool, fertile, and damp soils. -- Suitable for production of quality wines. Schwarzman: -- Prefers deep and moist soils. -- Ideal in areas with serious nematode problems.

79

What are some aspects of Riparia x Berlandieri based rootstocks? Examples?

Surface or semi surface rooting. Good rooting, high resistance to chlorosis. Good affinity with scions and resistance to phylloxera. 161-49C: -- Prefers cool, fertile, and permeable soils. -- high lime tolerance -- Med- resistance to nematodes -- Widely used in France, Germany, and Switzerland. -- Good fruiting. -- Good for acidic soils. 420A: -- Prefers cool, deep, rich, permeable soils. -- Medium lime tolerance. -- Good for quality vineyards. 5C: -- Works in a wide range of soils: Chalky, clayey, compact. -- Good nematode resistance. -- Suitable for quality vineyards in northern regions. -- Poor potassium uptake. 5BB: -- Works in a wide range of soils: Cold, fertile, permeable. -- Good resistance to nematodes. -- In fertile soil, this rootstock should not be grafted to varieties that are prone to Coulure. -- Poor uptake of Potassium and Magnesium. SO4 Selection Oppenheim: -- Average vigour. -- Prefers fertile, humid, and cold soils. -- Med- resistance to nematodes. -- Very fruitful. Most popular in Europe. -- Poor uptake of Mg--> coulure and stem atrophy. -- Several clonal variations available. 125AA: -- Works in a very wide range of soils. -- Average resistance to drought. -- Not recommended for varieties sensitive to coulure.

80

What are some aspects of Rupestris x Berlandieri based rootstocks? Examples?

Good for planting in dry, stony conditions. Deep or semi-deep rooting systems. High vigour. Good resistance to chlorosis, phylloxera, and drought. Better lime tolerance than straight rupestris. 99R: -- Prefers average fertility, deep, and permeable soil. -- Fruits well. -- Used in the South of France. 110R: -- Prefers deep, poor, clay-calcareous soils. -- Good rootstock for dry regions. -- Poor uptake of K and Manganese 140 RU: -- Prefers poor, dry soils. -- High lime tolerance. -- Suitable for mediterranean vine growing countries. 1103 P: -- Prefers poor, dry soils of average compactness. -- Warm climate rootstock. -- Saline resistant.

81

What are some aspects of Vinifera x Berlandieri based rootstocks? Examples?

Good resistance to lime and chlorosis. Some have poor phylloxera resistance. Fercal: -- Prefers dry, shallow, calcareous soils. -- Shows Mg Deficiency if K applications are too great. 41B: -- Prefers dry, calcareous soils -- Used in Champagne and Charentes. Some susceptibility to phylloxera. -- Good fruiting. -- Good uptake of Mg. 333EM: -- Prefers humid and compact soils. -- Used in Champagne, Charentes, and the Midi. -- Can cause Coulure.

82

What are some aspects of Vitis champini based rootstocks? Examples?

Important for regions with severe nematode problems. However, they tend to be extremely vigorous and unsuitable for high quality grapes. Dog Ridge: -- Prefers poor, lightly textured soils. -- Low lime tolerance. -- Weak Phylloxera tolerance. -- For regions with severe nematode problems. -- Lower quality potential than Schwarzman

83

Why are soil nutrient deficiencies usually not a concern for site selection?

Nutrient deficiencies rarely limit the use of a soil as corrective additions of the missing element can be made.

84

What are some practical and commercial considerations to be made for site selection?

-- Access to site for cars, tractors, electricity and water (The development of an isolated site on a steep slope, will be much more expensive than one that is linked to existing roads and not far from established energy supplies). -- Availability of labor -- will determine whether you need to machine harvest. -- Proximity to markets -- Reputation of nearby vineyards in the area.

85

How is planting density calculated?

It is calculated on a field of 1 Hectare. Planting density = # of Rows x # of vines in each row

86

What is a trellis?

A physical structure consisting of posts and wires that largely supports the grapevine framework.

87

Explain untrellised vine growing and name some areas where this is popular?

The "Bush" or "Free standing" vine is the oldest and least expensive way of growing a vine. The vine is trained short and there is no trellis. The low cost is often offset by the low production, especially in the early years. The vines are usually spur pruned and are referred to as "Bush vines" or "Gobelets." They can also be cane pruned by tying the canes together to form a basket such as on Santorini. Advantages: -- The Foliage can offer shade in warmer mediterranean climates, and canopy management costs are low. Negatives: -- Low yields -- More prone to disease due to leas air circulation through the canopy. -- Machine harvesting is not possible. Examples: Santorini, Beaujolais, other parts of Southern Europe.

88

Explain staked vines, and give examples of where they're found.

These have a post and thats all. These are driven into ground next to vine to which the vine is tied to for support. These can be trained higher than bush vines which simplifies vineyard operations. Also, the canopy can be positioned to allow greater air circulation which reduces disease risk. -- Vines are trained to form a crown (head) 20-30 cm above the ground and 2-4 canes are fixed to the stake. -- Alternatively the vines are spur pruned, without a distinct crown, with the bearers radiating from the trunk in a circular shape. Common in Cote Rotie, Southern France, Portugal, and parts of South Africa.

89

Explain single wire trellising.

Can either be cordon trained and spur pruned or head trained and cane pruned. Advantages: -- Relatively easy to install and train. -- Compared to bush vines, it has the advantage of allowing for a continuous row of foliage. Disadvantages: -- The new shoots often hang down, offering no protection to the fruit from sunburn.

90

Explain Two-wire trellising.

The most basic form of multi wired trellis systems, this is used throughout the world. It was widely adopted in the mid '80s when it was referred to as "California Sprawl." It consists of a single fruiting wire and above this a single foliage wire. This type of trellis can be suited to mechanical pruning and harvesting depending on the canopy. High potential sights will produce a lot of vegetative growth, which means more wires will be required to keep the foliage off of the ground.

91

What is VSP? Where is it used?

Vertical Shoot Positioning Trellis. It is widely adopted in France, Germany, cooler parts of Australia, and New Zealand. It is widely adopted in areas at high risk of fungal disease -- in order to keep foliage off of the ground and to simplify spraying and trimming operations. It consists of movable foliage wires which enable shoots to be trained to a narrow vertical canopy. Vines can either be cane pruned or spur pruned. Shoots are uniformly trained, so all the fruit is in one zone and shoot tips are in another -- This simplifies mechanical operations such as leaf removal, bunch zone spraying, and summer trimming. Advantages: -- All the fruit is in one zone. -- Vines can be machine harvested. Disadvantages -- Shoot density is normally high, so fruit is prone to over-shading. -- It is unsuitable for high vigor varieties and high potential sites.

92

What is the Scott Henry System?

A vertical divided trellis system. Consists of two fruiting wires which allows for a divided canopy. Suitable for machine harvesting. Developed in Oregon and trialled in NZ and AU. This has largely been replaced by Smart-Dyson.

93

What is Smart-Dyson?

A Vertical divided trellis system. Superseded Scott Henry.. The vine is cordon trained with upwards and downward facing spurs giving rise to the two separate canopies. Suitable for machine harvesting.

94

What are the advantages and drawbacks of Vertical decided trellising systems like Scott Henry and Smart-Dyson?

Pros: -- Canopy surface is increased by 60%, higher increased potential for photosynthesis. -- Shoot density is halved, so exposure is increased, which decreased disease incidence. -- There is a de-vigorating effect on the vine as half o the shoots are pointed downwards. Cons: -- Higher costs to establish these systems. -- Greater level of expertise needed to instruct workers how to train the vines.

95

What is the Geneva Double Curtain?

A horizontally divided trellis with shoots trained downwards. The system was specifically designed to improve yield and fruit composition in vigorous soils. The divided canopy reduces shading, and downward facing shoots meant that the basal buds and fruit were exposed to greater amounts of sunlight. These two factors combined were found to produce higher yields of better quality grapes. Normally spur pruned by machine and machine harvested. GDC can convert dense shaded canopies to low density ones, with more than 50% yield increases obtained compared to VSP. Drawbacks include the expense of the materials and expertise required to train the vines. Currently is is used in AU, CA, and parts of Italy.

96

What is the U-shaped, or Lyre, trellis?

A Horizontally divided trellis developed in France and has been adopted in California, New Zealand, Chile, Uruguay, and cooler regions of AU -- on medium to high vigor sites. Two shoots are trained upwards into two curtains, the shape resembling a lyre. Due to the open canopy, improvements in yield and grape quality have been found. It can be machine harvested and pruned. The drawbacks include a high cost of maintenance and construction.

97

What is the pergola/tendone trellis?

This overhead system is productive and is used in Chile Argentina and in Italy -- though now more common for table grapes. A system of wooden frames and cross wires support the foliage and the fruit and this framework is normally high enough for tractors to pass underneath. Limiting due to high labor costs and high costs of construction, Unsuitable for high potential sites as a very dense canopy forms leading to shading problems and an increased risk of powdery mildew and botrytis infection.

98

Above what incline should terraces start to be considered?

20%.

99

What is the aim of canopy management?

To improve quality and yield and minimize disease risk.

100

What is the replacement cane system?

Practice that was popularized by charles guyot in the late 1860's. The main advantage is that it limits vine vigour. A disadvantage is that it rte quires great skill and cannot be mechanized.

101

What is the function of Nitrogen in the vine and the effect(s) of its deficiency?

Second only to water in controlling plant growth. Major constituent of plant cell proteins, nucleic acids, chlorophyll, and hormones. When deficient vigour will be reduced, there will be smaller leaves and shoots, petioles may redden, and leaves will yellow.

102

What is the function of Potassium in the vine and the effect(s) of its deficiency?

Regulates water flow, sugar levels in the plant, and internal acidity. Activates enzymes. Encourages ripening. When deficient older leaves will yellow in white varieties and redden in red varieties. Defoliation follows. Uneven ripening.

103

What is the function of Phosphorus in the vine and the effect(s) of its deficiency?

Key element in energy fixation. Encourages ripening and root growth. When deficient there will be a gradual reduction in shoot growth. Reduced fruit set and low bunch numbers per shoot. There will be a yellowing between the veins of recently mature leaves. Sometimes red spots on leaves.

104

What is the function of Calcium in the vine and the effect(s) of its deficiency?

Regulates cell acidity, component of cell walls. Deficiency is rare because calcium abundance is not a problem in most vineyards.

105

What is the function of Magnesium in the vine and the effect(s) of its deficiency?

Essential component of chlorophyll, regulates internal acidity, and sugar metabolism. Encourages ripening. When deficient older leaves will yellow in white varieties and redden in red varieties.

106

What is the function of Sulfur in the vine and the effect(s) of its deficiency?

A component of proteins and enzyme co-factors. The widespread use of wettable dusting and lime sulfur foliar applications in vineyards eliminates any sulfur deficiency occurring.

107

What is the function of Iron in the vine and the effect(s) of its deficiency?

Involved in chlorophyll formation and energy trapping and transfer in photosynthesis and respiration. A diffuse yellowing of young leaves and new growth.

108

What is the function of Magnanese in the vine and the effect(s) of its deficiency?

A component of the catalysts involved in the synthesis of chlorophyll and in nitrogen metabolism. Deficiency results in a yellowing between the main veins in broad bands.

109

What is the function of Molybdenum in the vine and the effect(s) of its deficiency?

Involved in nitrogen metabolism. Deficiency effects are unknown.

110

What is the function of Copper in the vine and the effect(s) of its deficiency?

A component of the enzymes of oxidation. Not normally deficient in vineyards as it is often present in fungicidal sprays i.e. bordeaux mixture.

111

What is the function of Zinc in the vine and the effect(s) of its deficiency?

A component of a catalyst involved in cell metabolic reactions. A severe deficiency results in 'Little Leaf' symptoms and stunted growth.

112

What is the function of Boron in the vine and the effect(s) of its deficiency?

Involved in the internal regulation of growth by plant hormones. Deficiency results in poor fruit set, smaller berries, death of the shoot tip, yellowing between the veins of recently matured leaves.

113

When and why are fertilizers added to a soil?

They can be added before planting to correct soil deficiencies or lower acidity. They can also be added to established sites to fix deficiency problems with one or more nutrients. Straight fertilizers contain only one nutrient, while Compound fertilizers contain two or more. The latter is more expensive, but more common because they are more efficient.

114

What is mulching?

The spreading of matter onto the soil surface to suppress weeds and prevent light from reaching the young weeds. This ultimately produces a food source for the plant. Pros: -- Conserves water by reducing soil evaporation. -- Effective if spread thickly enough. -- Increases earthworm activity and surface soil microbial activity. -- Improves soil structure. -- Reduces erosion. -- Reduces soil temperature variation by limiting heat loss from soil at night and reducing maximum soil temperature. -- Protects roots from the cold. -- Can increase vigour and yield with little change in quality. Cons: -- Expensive to spread. -- Encourages superficial rooting. -- Can promote high vigour. -- Increases risk of frost. -- Risk of Nitrogen deficit. -- Possible increase in fire risk. -- Possible pest infestation.

115

What is Flood Irrigation?

Large quantities of water are required to flood irrigate correctly. Water is fed from a supply canal and run down the rows, or it is diverted through a vineyard by a system of levee banks. This ancient method is still used in some desert areas for bulk wine production and is still used by some premium producers in Argentina, though since the 1990s more expensive drip irrigation methods have been adopted.

116

What is Drip Irrigation?

Water is applied as drops to each vine from a plastic dripper connected to a plastic hose. This form of irrigation enables close individual control of water supply, and involves wetting a limited soil volume more frequently. Wastage of water is generally minimized, however there is a high cost of installation and maintenance.

117

What is Partial Rootzone Drying?

An irrigation technique designed to control vine vigor and maintain wine quality without significant crop reduction. This technique requires that approximately half of the root system be always in a dry or drying state while the remainder is irrigated. Becoming quickly established in both new and old world wine regions.

118

What is regulated deficit irrigation?

RDI uses water stress to control vegetative growth. It involves a water deficit being applied variably between fruit set and a month or so after version in order to restrict vegetative growth and thus decrease competition between berry ripening and vegetative growth. In some varieties, such as Shiraz, berry size is also reduced. RDI requires more careful monitoring of the soil content and is not advised for hot regions, because vines with limited soil moisture can suffer extremes of water stress and may lose their leaves. Water deficit typically results in slightly lower yields. Becoming quickly established in both new and old world wine regions.

119

What is Powdery Mildew/Oidium?

-- A fungus specific to grapevines. American species are less vulnerable than Vitis vinifera. -- Introduced to Europe in the 1800's, one of the most widespread wine diseases. -- Most damage occurs on young, green parts of the vine. Young leaves curl and develop dull grey patches with cobweb patches that are easy to rub off on both sides of the leaf during sporulation. Advanced infection leads to musty smelling canopies. -- Unlike other funguses it doesn't need rain. -- Growth rate is determined by temperature. Prefers temperatures between 21-25˚C. -- Can be spread from other vineyards by the wind. -- Most prominent in warm, cloudy but not rainy summers where vigorously growing vines produce a shady humid canopy. -- Controlled by canopy management to reduce leaf bunching. -- Sulfer sprays stop and cure the disease but will only work between 18-35˚C -- Preventative sprays at bud burst are beneficial as the disease is hard to eradicate once present.

120

What is Downy Mildew?

-- Fungus imported from USA to Europe. -- Lives within vine tissue not on surface like powdery mildew. -- Causes damage to the green parts of the plant, young leaves most susceptible. -- Flower infections cause the flowers to dry up and drop off. Berry infections cause the berry to go grey when young and dried up when older. -- Needs rainfall/water and warm temperatures for at least one hour for germination, motile spores are splashed onto the vine where they enter the vine pores to start infection. -- High risk years are rainy winters, springs, and stormy but warm summers. -- Controlled by canopy management to reduce leaf bunching and also pesticides based on copper salts (Bordeaux mixture for instance). -- Vines must be sprayed before rain starts to prevent.

121

What is Eutype dieback?

-- Often known as dead arm or dying arm -- Disease caused by a fungus called Eutypa lata, which enters through pruning wounds. -- Needs mild temperature and moisture. -- Common in South Eastern Australia, California, South west-france, and South Africa. -- The fungus blocks and kills water conducting tissue, eventually killing the arm. -- Symptoms are not often seen in young vineyards. -- Symptoms include stunted shoots with small yellow cupped leaves. Fruit quality is not affected, but yield is decreased. -- Controlled by vineyard hygiene -- Pruning wounds should be covered with a fungicide paste. Pruning should be done in early winter when spore numbers are low and also in dry weather to minimize risk of infection. -- Infected wood should be removed from the vineyard and burnt.

122

What is Phomopsis?

-- Fungal disease (Phomopsis viticola) sometimes called excoriose that has been particularly destructive since the 1950's due to increased vine vigour. -- Spreads slowly and very difficult to eradicate once present. -- Causes basal buds to lose viability, it restricts cane growth making them fragile. Can lead to a large decrease in yield. -- Symptoms can be noticed during first winter pruning, infected canes whiten and snap off easily. Berry symptoms are rare. -- Leaf symptoms common in USA but not Europe. -- small dark spots appear after rainfall, leaves become distorted and stunted, if enough spots develop, the leaf will fall off. -- It is introduced to the vineyard by infected planting material, will take a number of years for the disease to become apparent in the vineyard. -- Spreads in high humidity and lower temperatures -- therefore associated with damp vineyard areas with rainy cold springs. -- Controlled by buying planting material off of reputable suppliers. -- Really effective in treatment is a high winter dose of sodium arsenite but because of its danger to humans it is not approved for use in all vineyard areas.

123

What is Pierce's Disease?

-- Bacteria (Xylella fastidiosa) causes this deadly disease to vines. -- Spread by glassy winged sharpshooters -- these transmit the bacteria from host plants to vines while feeding. -- Caused widespread damage in southern California. Not present in Europe, Australia, and NZ, due to quarantine. -- Symptoms noticeable mid summer. Leaves discolor leading to leaf death over a period of a couple of weeks then the leaf drops off of the vine. New leaves growing to replace the fallen ones are stunted and slow to develop. -- Death of vine occurs 1-5 years after infection. -- No cure available.

124

What is Fanleaf Virus?

-- A number of viruses not just one come under the fan leaf virus heading. -- Shoot growth is malformed with double nodes, short internode pattern growth, leaves are distorted and asymmetric, look like fans and become yellow along the veins. -- Bunches are smaller with poor fruit set leading to millerandage and up to 80% crop reduction. -- Over time, varieties start failing to fruit -- especially on susceptible varieties like Cabernet Sauvignon. -- Spread by infected planting material. -- Controlled by buying planting material from certified nurseries that serotype and use thermotherapy on their vines. -- Also spread by a nematode feeding on an infected plant root then on healthy ones. -- No cure once a vineyard is infected. It will eventually have to be uprooted.

125

What is Leafroll virus?

-- The most widespread disease of grapevines worldwide -- Can have a serious effect on wine quality. -- Symptoms seen in autumn are red (black grapes) and yellow (white grapes) leaves with downward rolled edges. -- Can reduce yield by 50%, decrease berry sugar by 30% and delay maturity by four weeks. Wines made are lower in color, alcohol, flavor, and body. -- Spread by planting infected cuttings and vines. -- Controlled by buying planting material from certified nurseries that serotype and use thermotherapy on their vines. -- Mealybugs have been recorded as a vector for the virus in New Zealand and South Africa. -- No cure once a vineyard is infected. It will eventually have to be uprooted.

126

What are Grape Moths?

-- Flying insects which damage grapes in larval stage. -- Four most important types are pyrale, cochylis, European grape Moth, Eulia. -- In California, Orange Tatrix is the main moth. The Grapevine moth and the light brown apple moth do the most damage in Australia and New Zealand. -- Larvae feed mostly on foliage but most damage happens late summer when they begin feeding on bunches. The larvae web berries together feeding on the surface before tunneling into them, wounds are open to attack from other diseases such as botrytis. -- Can cause crop loss in spring by eating new shoots. -- Natural enemies such as spiders, wasps and shield bugs can be used to combat.

127

What is Arched (Pendelbogen) training used to achieve?

An even vigour along the cane.