1.2.3 - Vineyard Management Options Flashcards
1
Q
Define ‘Cutting’
A
Section of a vine shoot that can be planted and will then grow as a new plant, genetically identical to its parents with generally the same characteristics
2
Q
Identify the pros of using ‘Cuttings’ for propagating a vineyard
A
- Many small cuttings can be taken from a vine and propagated at the same time
- Permits the use of rootstocks
- Nurseries can treat them to avoid spreading diseases
3
Q
Define ‘Layering’
A
Method of filling gaps in a vineyard by using shoots from an established neighboring vine to propagate a new vine
4
Q
Identify pros and cons of ‘Layering’ for propagation
A
Pros: Inexpensive; new plant genetically identical to parents with generally the same characteristics
Cons: New vine grows on its own roots, not those of a rootstock so not always suitable because has no protection provided by a rootstock
5
Q
Describe how ‘layering’ is accomplished to propagate a new vine
A
Cane from neighboring vine is bent down and a section buried in the ground with the tip of the cane pointing upwards out of the ground. The buried section takes root and, once roots are established, the cane linking to the new growth to the original plant is cut.
6
Q
Define a ‘Clone’
A
Random mutations in the genetic code in a new vine propagated from cutting or layering. Even though usually genetically identical to the parents, these mutations may cause the new vine to have slightly different characteristics.
7
Q
Define ‘Clonal Selection’
A
When vines with positive mutations are selected for further propagation by cutting so that the positive characteristics of these vines can be carried forward into new plantings.
8
Q
Provide examples of Clonal Selections
A
Pinot Noir Clone 115 - low yields of small grapes - high quality red wine production
Pinot Noir Clone 521 - higher yields of bigger grapes, sparkling wine production
9
Q
Provide examples of Clones that are considered separate grape variety
A
Brunello di Montalcino is clone of Sangiovese
Pinot Blanc, Pinot Gris, Pinot Noir, Meunier are all mutations of Pinot
10
Q
Describe the pros and cons of using the same clone of grape variety to propagate a new vineyard
A
Pros: (1) All vines grow in a similar way and ripen grapes at the same time, making vineyard management simpler; (2) clone keeps the name of its parent variety so no confusion in the marketplace
Cons: (1) less diversity in the fruit and, hence, may produce a wine with less complexity and balance (if style going for); (2) vineyard is more susceptible to disease because every vine is equally susceptible
11
Q
Define ‘Mass Selection’
A
Technique that requires vineyard owners to take cuttings from the vines in their own vineyards and cultivate these cuttings (can even send to nursery for grafting). Cuttings are taken from several of the best performing vines, which are selected after years of monitoring and recording.
12
Q
Describe the pros and cons of ‘Mass Selection’
A
Pros: (!) increases the diversity of planting material in the vineyard and throughout the region; (2) owner is using its own unique planting material, which can enhance fruit quality and/or yield (and can be used as a marketing asset)
Cons: (1) selection and monitoring of vines to ensure propagation of the best vines is costly in terms of time and labor; (2) if parent vine is infected by disease, likely to be passed onto the new vines, spreading the disease.
13
Q
Define ‘Cross-Fertilization’
A
Occurs when pollen from the anthers of a flower of one vine are transferred to the ovary of the flower of another vine and fertilization occurs. Grapes develop and the seeds from these vines are planted and grown. The new vines are a new grape variety and will have different characteristics. If characteristics are desirable (as measured over a long period - 2 to 3 years, then may be propagated by cuttings to create identical vines. And, if there could be value from commercial availability, then registered on the OIV catalogue as a new grape variety.
14
Q
Define ‘Cross’
A
When a new variety is produced from two parents of the same species; normally reserved for new varieties bred by researchers, whose aim is to create an offspring that has favorable characteristics of the two parents vines
15
Q
Identify examples of ‘cross’ varieties
A
Muller Thurgau (Riesling x Madeleine Royale) - created to have the fruit quality of Riesling and high yield of Madeleine Royale; instead, high yields but not the fruit quality
Pinotage (Pinot Noir x Cinsault)
16
Q
Define ‘Hybrid’
A
When a new variety is produced from two parents of two different vine species
17
Q
Identify examples of a ‘Hybrid” grape
A
Vidal Blanc (Ugni Blanc (v. vinifera) and member of the Seibel family (American) - grown in Canada.
18
Q
Explain how ‘Hybrid’ grapes are generally used
A
Most hybrids do not produce fruit that matches the quality of most V. vinifera vines, but their other characteristics make them useful as rootstocks.
19
Q
Provide an example of a new grape variety occurring because of cross-fertilization in the wild
A
Cabernet Sauvignon (Sauvignon Blanc and Cabernet Franc)
20
Q
Explain why new varieties aren’t created very often
A
Knowledge of grapevine genetics has made it easier for sciences to use genetic markers to select offspring with characteristics they want without having to wait for the vine to grow and bear fruit, consumers resist new grape varieties.
21
Q
Identify the vineyard management options that may need consideration at the time a vineyard is established
A
Nutrients and Water: (1) soil health; (2) nutrients (minerals, weed control); (3) water management
Canopy: (1) grape variety; (2) rootstock vigor; (3) planting density; (4) row orientation - vine balance
Hazards: (1) too much and too little water; (2) freeze & frosts; (3) too much and too little sun and heat; (4) fires
Pests & Diseases
22
Q
Define ‘soil health’
A
Continued capacity of the soil to act as a living ecosystem that sustains plants, animals, and humans
23
Q
Identify the components of the soil structure
A
good drainage
sufficient water-holding capacity
sufficient oxygen
ability to resist erosion
ability to allow roots of vine to penetrate to sufficient depth
24
Q
Define ‘humus’
A
Humus is formed as organic matter (e.g., plant material deposited on vineyard floor during and after the growing season) breaks down, supplying nutrients to the soil and improving the soil structure and its water-holding capacity.
25
Explain how humus benefits the soil.
(1) acts as a buffer between the vineyard floor and the roots, absorbing moisture falling on the vineyard and allowing it to be released slowly
(2) acts as a binder in soils, helping keep fragile soils together, preventing erosion and soil loss
(3) prevents soil compaction which might be caused by tractors and machinery
(4) opens up the soil, allowing air to penetrate to lower levels and CO2 produced by the roots to escape
(5) helps the soil trap nutrients to release slowly to the roots
26
Explain how poor soil health can impact the vineyard
Poor soil health can lead to problems with availability and uptake of nutrients and water and, therefore, poor vine growth and ripening.
27
Explain how a vineyard owner addresses soil health
Test soils prior to establishing a vineyard and annually thereafter to identify corrective measures
28
Identify the top three nutrients required by a vine
Nitrogen
Phosphorous
Potassium
29
Explain how a vineyard owner addresses nutrient management
(1) direct application of nutrients (either organic or inorganic form), i.e., fertilizers
(2) promote biological activity and soil structure
(3) manage weeds that can compete for nutrients and water
30
Explain when fertilizers are applied in a vineyard
Before planting to help the growth of young vines
Established vineyards to correct deficiencies
31
Identify what constitutes an organic fertilizer
Derived from fresh or composted plant or animal material, e.g., manure or slurry
Green manure
32
Identified the pros and cons of using organic fertilizers
Pros: (1) cheap or even free; (2) some high in humus and therefore good for soil structure and water retention; (3) in organic form so they provide nutrition for soil organisms, promoting living matter in soil and because they need to be broken down, they become available to the vine gradually
Cons: (1) need to be broken down to inorganic by soil organisms, so they need to be incorporated which requires labor; (2) bulky and, therefore, expensive to transport and spread
33
Define 'slurry'
manure in semi-liquid form
34
Define 'green manure'
Cover crops that are grown, mown in, and turned into the soil to decompose and provide nutrients.
35
Define inorganic fertilizers
manufactured from minerals extracted from the ground or synthetic chemicals, also known as synthetic fertilizers
36
Identify the pros and cons of inorganic fertilizers
Pros: (1) can be more tailored than organic because can be single or several nutrients; (2) more readily available to vines because already inorganic form; (3) cheaper to transport and deliver because in a concentrated form
Cons: (1) holds no benefit for soil organisms and does not improve soil structure; (2) more expensive to purchase than organic fertilizers
37
Identify five methods for controlling weeds in the vineyard
Cultivation
Herbicides
Animal Grazing
Cover Crops
Mulching
38
Define 'cultivation'
Method of weed control that involves ploughing the soil to cut or disturb the weeds' root systems
39
Identify the pros and cons of cultivation for weed management
Pros: (1) does not use chemicals; (2) enables fertilizers and, where relevant, mown cover crops to be incorporated into the soil at the same time weeds are removed
Cons: (1) repeated cultivation can damage the soil's structure and ecology due to breakdown of organic matter and disruption of earthworms in their habitat; (2) costly as it requires skilled labor and machine driver; (3) buries seeds, thus encouraging weeds to grow back; (4) can increase vine vigor too much as there is no competition for water or nutrients (could also be a pro)
40
Define 'herbicide'
Chemical spray that kills weeds
41
Identify the three types of herbicides
Pre-emergence herbicides - persist in the surface layers of the soil and are absorbed by the weeds' roots, thereby inhibiting germination of young seedlings
Contact herbicides - sprayed on established weeds and kills the green parts of the weed, resulting in the death of the plant
Systemic herbicides - sprayed on established weeds and taken in by the leaves. Herbicide travels up and down the weed in the sap and kills the whole plant
42
Identify the pros and cons of using herbicides for weed management
Pros: (1) cheap in terms of labor and machinery; (2) highly effective, particularly in the under-row area; (3) less damaging to the soil than cultivation
Cons: (1) risks of poisoning to operator, consumer and environment, does not encourage vineyard ecosystem; (2) weeds can become resistant and therefore larger doses or different chemicals needed; (3) can increase vine vigor too much as there is no competition for water or nutrients (can also be a pro); (4) not allowed in organic and biodynamic viticulture
43
Identify an example where weeds became resistant to herbicide use
South Africa - routine use of glyphosate now means growers face a glyphosate-resistant rye grass
44
Identify the pros and cons of animal grazing to control weeds
Pros: (1) does not use chemicals; (2) animals provide vineyard with manure; (3) animals can be source of meat for humans
Cons: (1) vines must be trained sustainably high or grazing must be conducted out of growing season; (2) animals need caring for if they belong to the owner, which requires labor; (3) animals susceptible to vineyard pesticides
45
Define 'cover crops'
Plants that are specifically planted, or allowed to grow, that have a beneficial effect on the vineyard
46
Identify the reasons why cover crops are used in a vineyard
Suppress weeds
Improve overall soil structure
Compete with vine for nutrient and water availability (in fertile sites)
Manage soil erosion
Enhance biodiversity
Provide surface to drive on
47
Identify the types of cover crops often used in a vineyard
Those quick to establish and adapt to soil and climatic conditions (Australia and California have indexes for matching)
Legumes (beans and clover, mustard, peas, vetches)
Cereals (ryegrass and oats, wheat, barley)
Natural vegetation (cheap and greater diversity but characteristics aren't as known as a specific cover crop so not as much control)
48
Identify the pros and cons of using cover crops
Pros: (1) no chemicals, increases soil biological activity and biodiversity; (2) influences vigor of vine by introducing competition (but need to manage so not too much competition at key times in vineyard cycle); (3) provides good surface for machinery (esp in climate with high annual rainfall); and (4) green manure
Cons: (1) reduces vine vigor through competition (can be excessive in poor soils and dry environments); (2) difficulty of mowing the under-row area so time and labor; (3) unsuitable for steeply sloping vineyards as they are slippery when wet
49
Define 'mulching'
The spreading of matter onto the vineyard soil to suppress the growth of weeds; usually made of biodegradable materials that ultimately provide nutrients for the vines. Materials with higher nutrient content can be used in nutrient-poor vineyards.
50
Identify the pros and cons of mulching to control weeds
Pros: (1) no chemicals; (2) reduce water evaporation from soil (dry climates); (3) ultimately source of nutrients and humus, which promotes soil biological activity and good soil structure
Cons: (1) bulky and therefore expensive to transport and spread; (2) only effective if applied in a thick layer, so a lot is needed; (3) can increase vigor too much as no competition for water or nutrients
51
Explain who might use irrigation in the vineyard
Dry climate or very free-draining soils
Permitted by regulations (In EU, not permitted or only in emergency situations such as establishing young vines or during a drought that threatens the livelihood of the growers)
Easy source of clean water
52
Explain the methods being used by grape growers in regions experiencing extreme shortages in water supply
Water-efficient irrigations systems and techniques with better monitoring of water take-up by the vines (dripper system and regulated deficit irrigation)
Drought tolerant grape varieties, Grenache, and rootstocks, 140R
Reducing evaporation (mulch)
Reducing competition (removing weeds)
Increasing humus levels in the soil to improve water retention (add organic matter such as compost)
Promoting growth of vine roots deep into soil (cultivation)
Reuse water in the winery for max efficiency
53
Explain how the water quality available impacts irrigation
If water is high in dissolved solids (mud), can block sprinkler and drip irrigation and therefore needs settling and filtering before use
If water is high in salt then water increases salt level in soil and makes it more difficult for the roots to take up the water, which means the vines becomes dehydrated, green parts start to wilt, and the plant eventually dies. This is especially the case with drip irrigation because the salt accumulates at the root zone, rather than being washed deeper into the soil with flood irrigation. Particular concern in Australia.
54
Identify four types of irrigation used in the vineyard
Drip irrigation
Flood irrigation
Channel irrigation
Overhead sprinklers
55
Explain how drip irrigation is installed in the vineyard
Done prior to planting; narrow water pipes are laid along each row and typically tied to the lowest trellis wire. Drippers are fitted at appropriate intervals and positioned far enough away from vines to encourage roots to grow and seek out water.
56
Identify the pros and cons of drip irrigation
Pros: (1) permits economic use of water; (2) possible to control water supply to individual rows or blocks of vines, allowing more tailored management and thus potentially higher yields and quality; (3) used to supply liquid fertilizer; and (4) can be used on slopes
Cons: (1) installation costs are high but maintenance costs moderate; (2) clean water is required otherwise dripper become blocked; (3) even with clean water, drippers become block by algae, bacteria or high levels of minerals and salts - maintenance required; (4) cannot be used in frost protection because droppers are below the vine's green parts
57
Define 'ferrigation'
where liquid fertilizer is added to the water supply via a dosing pump and applied via irrigation (drip or overhead)
58
Explain how flood irrigation is used in the vineyard
Water is stored behind a sluice and, at scheduled times, released to flood the vineyard.
59
Identify the pros and cons of flood irrigation
Pros: (1) cheap to install and maintain; (2) vineyards can be planted on their own roots as phylloxera is drowned by repeated submersion in water
Cons: (1) inefficient as a lot of water is not taken up by the vine; (2) can only be used on flat or gently sloping land
60
Identify a region that uses flood irrigation
Mendoza (and may Chilean vineyard areas) because they have ample water from the Andes.
61
Explain how channel irrigation is used in the vineyard.
Narrow channels are dug alongside rows of vines and water directed into them from header channels that are supplied from feeder canals that traverse the uphill side of the vineyard
62
Identify the pros and cons of channel irrigation
Pros: none mentioned
Cons: (1) not suitable where water supply is limited; (2) channels can get easily damaged by tractors and implements; (3) channels often fill up with foliage and will need to be removed before they work effectively
63
Identify a region that uses channel irrigation
Common in Argentina because of abundant water from the Andes
64
Explain how overhead sprinklers are used in the vineyard
Water is pumped to the sprinklers, which shower it over the vineyard
65
Identify the pros and cons of overhead sprinklers
Pros: (1) can be used for frost protection (this alone can be a deciding factor)
Cons: (1) expensive to install and maintain due to the water pressure needed; (2) uses large amounts of water as evaporation levels are high when the water is sprayed through the air before landing on the crops; (3) may increase humidity levels which may exacerbate disease levels
66
Explain how water stress can be used in the vineyard
Dry climates have the option to put the vine under mild stress at appropriate times if they control the water supplied to the vine via irrigation.
Plentiful water in the spring encourages establishment of large leaf surface area to support production of high yields; whereas mild water stress can be desirable between fruit set and version to stop the growth of shoots and encourage grape development and ripening
67
Define 'regulated deficit irrigation'
System of timing and regulating amount of irrigation so that a vine is put under mild to moderate water stress for specified time within the growing season
68
Explain how RDI is used in the vineyard
Usually scheduled between fruit set and version to limit further shoot growth and encourage grape development
Dripper irrigation provides best control
Easiest in regions with dry growing season and sandy or loam soils that dry out and can be re-wetted quickly; more difficult in regions with heavy rainfall in spring and/or frequent rain during growing season and with heavy clay soils that take a long time to dry out
Often favored for back grapes as it can reduce grape size, which increases proportion of skins to juice and hence increases concentration of anthocyanin and tannins (quality)
69
Identify the pros and cons of using regulated deficit irrigation
Pros: (1) vine growth and grape development are better controlled; (2) less water is used
Cons: (1) even if carried out successfully, lower yields, therefore need to be confident that improvements in grape quality will make up for yields; (2) additional costs (assuming drip irrigation already) in equipment to monitor and respond to moisture in soil
70
Define 'dry farming'
Not using irrigation in areas with limited rainfall in the growing season; can lead to lower yields but improved grape quality
71
Explain how vineyards manage too much water
Fast-draining soils
Artificial drainage system
Leave natural vegetation to grow or plant specific crops to provide competition for water, leaving less available for vine
Improve soil structure and remove plough pans to better regulate water drainage
72
Explain how artificial drainage systems are used in the vineyard
Done before vineyard is planted; cost of installation and maintenance typically more than offset in medium term by having healthier, better-balanced vines that are better able to ripen grapes consistently
73
Identify core benefit to good drainage
Aids mechanization in the vineyard by providing better surface to drive on and reduces soil compaction that results from driving on wet soils
74
Define 'canopy management'
Organization of the shoots, leaves, and fruit of the vine in order to maximize grape yield and quality
75
Identify the key aims of canopy management
Maximize effectiveness of light interception by the vine canopy
Reduce shade within canopy (or provide a certain amount of shade in hot temps and intense sun)
Ensure microclimate for grapes is as uniform as possible so grapes ripen evenly
Promote balance between vegetative and reproductive functions of vine
Arrange vine canopy for mechanization or manual labor
Promote air circulation through canopy to reduce incidence of disease which influences yield and grape health
76
Explain how air circulation through the canopy impacts incidence of disease
Dense, shaded canopies dry out more slowly after rainfall or morning dew and provide suitable conditions for fungal diseases to develop
Dense canopies also more problematic when spraying fungicides because difficult to ensure fungicide reaches all areas of canopy
77
Define 'bud fruitfulness'
Number of inflorescences developing inside a latent bud; determined during prior growing season
78
Explain how light interception by the vine canopy impacts bud fruitfulness
Exposure to sunlight - greater bud fruitfulness and hence has positive implications for grape yields in next growing season
Shady conditions - reduced bud fruitfulness, with bud producing more vegetative structures rather than reproductive structures
79
Identified how exposure of leaves and grapes to sunlight impacts the level and balance of grape components
Increased sugar levels through greater overall photosynthesis
Increased tannin leaves and greater polymerization of those tannins, leading to less bitterness
Enhanced anthocyanin development in black grapes
Decreased malic acid
Increased levels of some favorable aroma precursors and aroma compounds
Decreased methoxypyrazines which give herbaceous characters
80
Define 'anthocyanin'
Colors in grape varieties
81
How does sunlight impact acids in the grape
Warmer grape temps lead to more malic acid being broken down in cellular respiration.
In cool climates, acidity levels in wine can be unpleasantly high (tartaric acid remains)
82
Define 'optimal yield'
Yield that will allow the grape grower to grow maximum weight of grapes that have the required composition for the desired wine style and quality
83
Explain a 'balance cycle'
(1) Until veraison, the vine's sugars and nutrients are mainly allocated to shoot and root growth and storage
(2) After veraison, sugars and other compounds needed for growth are mainly allocated to the fruit and shoot growth is depressed - canopy is less likely to become dense and shady; light exposure in the canopy is improved; leads to high quality fruit and enhanced bud fruitfulness the next growing season
The concept of the balanced vine sounds good in theory, but in practice, it is elusive and difficult to capture.
84
Define 'undercropping'
Yield of fruit is too low for the vigor of the vine and shoot growth continues through the vine cycle because there's not much fruit to ripen.
A vine that is carrying too little fruiting wood will tend to grow too vigorously with the result that both crop and canopy will be shaded.
85
Explain the impact of undercropping on the vineyard
Growing shoots and leaves compete with grapes for sugar and other compounds needed for growth, which negatively affects grape formation and ripening, leading to a dense, shady canopy and hence lower quality fruit due to lack of sunlight interception and lower yields due to reduced bud fruitfulness.
86
Define 'vegetative cycle'
When low yields in the next season lead to undercropping
87
Define 'overcropping'
Yield of fruit is too high and vine may need to gain sugars from the carbs stored in the trunk, cordons, and roots (which are being stored for winter and early spring), thereby weakening the wine in future years
A vine that is carrying too much fruiting wood will be less likely to ripen that crop and may not be able to provide itself with enough reserves for its long-term health
88
Identify six other influences on a vine's vigor
Growing environment - warm temps, enough water and fertile soils means vines can grow vigorously, producing lots of shoots and leaves which leads to a high capacity to photosynthesize and produce sugars and other compounds needed for growth, leading to successfully ripened large yields.
Grape variety and rootstock - vigorous grape varieties (Cab Sauvignon) and clones can grow larger and ripen a larger yield given similar environmental conditions to low vigor grape varieties (Merlot)
Presence of diseases
Very old vines less vigorous than those between 10-40 yrs old
Wine style being produces - grapes for rose can generally sustain larger yields than those producing grapes for red wines as tannin ripeness less critical
Pruning - winter pruning influences number of shoots and potential yield in coming growing season; summer pruning to amend vine balance and enhance ripeness
89
Define 'yield'
Measure of the amount of fruit produced, measured per vine (e.g., kg per vine) or over a set area (e.g., kg per hectare or tons per acre)
90
Explain how yield is related to vine balance
Link between yield of a vine and quality of fruit because if overcropped or underpropped, then out of balance and fruit produced is lesser quality
Yield at which vine is balanced depends on natural resources of vineyard, planting material (incl age of vine and presence of any disease), and wine styles; therefore, some vines balanced at higher yield than others
91
Explain what yield over a set area depends upon
Yield over a set area depends on (1) yield per vine and (2) planting density
Even if yield per vine is low, vines may be planted very densely to gain as much yield over a set area
EU specifies max yields per set area
92
Identify the techniques used in canopy management
Vine training
Winter pruning
Vine trellising
Overall plant vigor management (fertilization, irrigation, cover crops, etc.)
Summer pruning
93
Considerations when establishing vineyards
Vine Density
Row Orientation
Vine Training, Pruning & Trellising
94
Define 'vine density'
Number of vines that are planted per hectare of v vineyard and range from as low as a few hundred vines per hectare to over 10,000 vines per hectare
95
Explain why vine density needs to be considering during vineyard establishment
Influences within-row spacing and between-row spacing
96
Identify what influences Optimal Vine Density
Vigor of vine, which is influenced by natural resources and planting materials
Type of trellising system used
Access needed between vines
97
Explain how vigor of vine influences Optimal Vine Density
Low vigor vines that are VSP trellised can be planted very closely together within the row as the individual vines are relatively small and planting them further apart would not maximize the vineyard land but would, instead, leave gaps in the canopy within vine rows, which would not be efficient especially in expense land such as Grand Cru Burgundy vineyards
High vigor vines need greater within-row spacing to grow and be in balance. If planted too closely, then overlapping canopies and increased sharing, which would reduce ripeness and quality.
Vines in dry regions without irrigation may be planted at low density, even in large, so that roots can spread out without competition from other vines in search of as much water as possible
98
Identify what influences between-row spacing
plant far enough apart so that one row does not shade the next, i.e., vigorous vines that are high trained and trellised need greater spacing
accommodate width of any machinery that might be used
99
Explain how climatic and logistical factors influence row orientation in the vineyard
North-South: provides most even sunlight through the canopy; however, afternoon sun is warmer, so grape bunches on the west side may require more shading from leaves to protect from sunburn
Reasons why easterly or westerly orientation might be favored:
Prevailing winds require orienting row 90º angle to direction of wind to provide protection
Orienting parallel to the longest side of the vineyard or existing feature (roadway, hedge or neighboring property) to maximize efficiency. This ensures rows are as long as the can be (within Eason) and that the number of rows is minimized.
Up and down the slope if unterraced vineyard are on slopes at an angle greater than 10%, otherwise machinery may slip
100
Identify the three factors on which vine training, pruning and trellising depend
Vine vigor
Site topography
Need for mechanization
101
Identify the factors on which vine vigor depends
natural resources available to vine (temp, water and nutrients)
planting material (variety, clone, rootstock)
presence of any diseases
as influenced by humans (e.g., RDI)
102
Define 'vine training'
Shape of permanent wood and is either head trained or cordoned trained
103
Describe head-trained vines
Relatively little permanent wood
Generally consists of trunk and, sometimes, a few short stubs growing from the top
Can be spur-pruned or replacement cane-pruned
Can be low- or high-trained
104
Describe cordon trained vines
typically has a trunk and one or more permanent horizontal arms of permanent wood, called cordons
usually spur-pruned
can be low- or high-trained
takes longer to establish than head training due to greater amount of permanent wood
105
Compare high vs low trained
either can be used for head trained or cordon trained vines
Low trained - trunk is kept short to benefit from heat retained by soil and/or provide greater protection from wind
High trained - avoid frosts or make manual interventions such as harvest easier
Some trellising can only be used with high trained vines
106
Define 'vine pruning'
Removal of unwanted parts of the vine
107
Explain how winter pruning impacts potential yield
Determines number and location of buds that will form shoots in the coming growing season
108
Define 'spur'
Short sections of one-year-old wood (shoots from last growing season that have lignified) that have been cut back to only two or three buds; distributed along a cordon or around top of trunk
109
Identify the pros of spur pruning
Number of retained fruiting buds is almost always higher than cane pruning
Number of buds can be increased or decreased at every annual pruning depending on desired yield
Larger yield per meter of row length permits row widths to be greater for any given yield when compared to cane pruning, thus allowing the use of wider (and more efficient) machines
larger number of buds per vine - and therefore the larger number of shoots and bunches - tends to depress the overall vigor of the vine which is useful in irrigated high vigor vineyards
Pruning can be partially mechanized and pre-pruning machines can greatly reduce the man hours required for pruning
Easier pruning system to learn how to prune and quicker to carry out, which has positive financial implications
110
Identify the cons of spur prunings
Yields will be lower for those varieties having blind buds on the first few buds away from the older wood
buds near the older wood more prone to fungal diseases as the older wood becomes a repository for diseases
unless some shoot-selection carried out early in the season, shoots, canes and fruit will be too crowded and canopy too dense
Cropping potential too high for vines in regions with the possibility of adverse weather during ripening period
111
Define 'replacement cane pruning'
Canes are longer sections of one-year-old wood and can have between 8 and 20 buds; typically laid down horizontally and tied to trellis for support and positioning
112
Identify the advantages of replacement can pruning
All the buds for the current year's cropping are borne on one-year-old canes with buds well away from older, more disease-prone, wood
Buds are all evenly spaced at about the right distance apart so that annual shoots are not too crowded
113
Identify the disadvantages of replacement cane pruning
More complex than spur pruning and requires skilled labor force to select suitable canes and train them
number of retained fruiting buds along a given meter of row length is restricted to the number of buds on any given length of cane, multiplied by the number of canes retained and no opportunity to increase this number.
Canes are more prone to frost damage
114
Explain how winter pruning impacts vine balance
Number of buds left depends on the vigor of the vine which influences the number and size of shoots in the growing season and amount of fruit, which influences the balance of the vine
115
Define 'trellis'
Permanent structure of posts and wires that helps to support and position a vine's shoots
116
Define 'bush vine'
Free-standing [head- or ]spur-trained system without support wires
117
Identify the pros and cons of bush vines
pros: (1) easy and inexpensive to develop; (2) shoots may droop down, providing shade for the grapes and preventing sunburn (e.g., Mancha, Spain)
cons: (1) not suitable for mechanization; (2) if vine is too vigorous, canopy can become too dense and shade fruit too much and increase pressure of fungal disease
118
Identify the pros and cons of trellised vineyards
Pros: shoots can be spread out (1) to maximize light interception, (2) increase air flow through the canopy which reduces fungal disease, and, (3) by positioning the fruit in one area, aid mechanization
Cons: (1) expensive to establish; (2) maintenance required
119
Define 'vertical shoot positioning'
System whereby a vine's shoots are trained vertically and held in place on the trellis, forming a single narrow canopy
Used on both head-trained, replacement cane-pruned vines (guyot) and cordon-trained, spur-pruned vines
120
121
Explain why a more complex training system than VSP would be used
VSP best suited to vines with low or moderate vigor; if vigor too high, canopy can be too dense, resulting in too much shading of leaves and fruits
More complex training systems split the canopy to reduce shade and maximize light
122
Define 'Geneva Double Curtain'
Horizontally split canopy; spur-pruned divided canopy system where the foliage hangs down in two curtains; can be machine-harvested; originally developed in NY State
123
Define 'Lyre'
Horizontally split canopy; cane or spur-pruned system with two VSP leaf-walls coming off one vine so looks like a lyre if viewed end-on.
124
Define 'Smart-Dyson'
Vertically split canopy; annual wood comes from two opposed cordons with both upward and downward facing spurs; first used in Gilroy, CA
125
Define 'Scott Hentry'
Vertically split canopy; cane or spur-pruned system with four canes or four cordons where the annual growth from the top wood is trained vertically and from the bottom wood downwards; popular in N Zealand
126
Identify the pros and cons of a complex training system
Pros: possible to make best use of vineyard space and resources to produce large yields of high quality fruit
Cons: complex, more difficult to manage and mechanize
127
Identify the aims of summer pruning
enhance grape ripening
reduce chance of fungal disease
make vineyard easier to manage
128
Define 'disbudding'
Removal of buds to manage vine balance and yields and, if necessary, comply with grape growing regulations
Removal of buds that are poorly positioned, e.g., facing downwards or too close together
Removal of buds of non-fruit-bearing shoots, which may compete with grapes for sugar and other resources
Cannot be mechanized
129
Define 'shoot removal'
Removal of shoots, often laterals, that are infertile or poorly positioned (too close together or low down on the trunk) to maintain well-organized, open canopy
130
Define 'shoot positioning'
Shoots are tucked into trellis wire to better organize the canopy and facilitate mechanization
131
Define 'pinching'
Removes the shoot tips at flowering to improve fruit set; cannot be mechanized
132
Define 'shoot trimming'
Cutting shoots to limit growth and reduce canopy thickness to enhance fruit ripening by reducing competition for carbs between shoot tips and fruit; also lowers disease pressure through better air circulation and improved spray penetration
133
Define 'leaf removal'
removing leaves to reduce shading of fruit and enhance ripening; also lowers disease pressure through better air circulation and improved spray penetration (careful not to expose grapes to too much sunshine and potential sunburn in warm and hot climates)
134
Define 'crop thinning'
Also known as green harvesting; removal of bunches of grapes to increase ripeness of grapes left on the vines; if done near version, can enhance ripening
Removal of least ripe bunches to improve uniformity of ripening and enhancing quality if fruit ripening is uneven
135
Identify three factors that would lead to uneven fruit ripening
Uneven bud burst or fruit set
Frost
Presence of bunches on lateral shoots
136
Identify 7 summer pruning techniques
Disbudding
Shoot Removal
Shoot Positioning
Pinching
Shoot Trimming
Leaf Removal
Crop Thinning (Green Harvesting)
137
Identify hazards in the vineyard
Drought / Excess Water / Untimely Rainfall
Freeze / Frosts / Hail
Sunburn / Fire
138
Explain how drought impacts the vineyard
Lack of water causes a vine to close the stomata on their leaves in order to limit water loss. This, in turn, reduced photosynthesis. If this continues, the growth of the plant is impaired, grape size is reduced, and ripening slows down potentially resulting in unripe grapes and lower yields. If prolonged, the plant will lose its leaves and then die.
Whole vineyards can be lost if water is scarce and no irrigation, e.g., Olifants River in S. Africa
139
Identify the management options for drought
Irrigation systems if allowed. EU allows in emergency (establish young vines, drought that threatens livelihood)
Rootstock, e.g., V. rupestris and V. berlandierie (110R and 140R)
Drought-tolerant variety, e.g. Grenacha
140
Explain how an excess of water can impact the vineyard
Lead to much vegetative growth, which can compete with grape ripening and too much shading of fruit, resulting in less ripe grapes
Increases humidity, thereby making the canopy more prone to fungal disease
Waterlogging can occur if soils aren't free-draining, which reduces the amount of oxygen available to the roots, which slows down growth and eventually kills the vine
Waterlogging can also lead to compacted soils, making them difficult to work, and uncontrolled water run-off
141
Explain how growers manage excess water
If on regular basis:
plant on slope
plant on free-draining soil
construct drainage system
142
Explain how untimely rainfall impacts the vineyard
During pollination and fruit set can lead to millerandange or coulure, which reduces the size of the crop and potential quality
During summer can reduce the rate of ripening of the fruit as mild water stress before version reduces the growth of shoot tips, which allows the grapes to ripen more satisfactorily
Close to harvest can lead to the grapes being swollen with water which reduces the concentration of must and quality of wine and the grapes can split, leading to grey rot.
Plus makes working harvest very difficult, e.g., difficult using technical harvesters or pickers accessing the vineyard esp if on clay soils
143
Explain how growers manage untimely rainfall
Choice of site (climate in general, slope), condition of soil, choice of whether or not to grass the land between rows of vines and adequacy of drainage mitigate some effects
Monitor weather forecast and weigh options of early harvest with potentially less-ripe fruit or taking a chance on the weather improving in time for a successful later harvest or losing par tor all of the crop
144
Explain how a freeze may impact a vineyard
If temps <-20ºC (-4ºF), then serious damage or even death can occur even though fully dormant vines are relatively hardy
Graft is part most at risk if above surface; cans or cordons are next at risk
Frost can kill canes or cordons, which reduces yields, or all parts of the vine above the ground
145
Identify the region most likely affected by freezes
Continental climate, e.g Canada, Washington, China
146
Explain how growers manage freeze risk
Site selection: (1) hillside sites can be up to 5ºC (9ºF) warmer than valley floor; (2) large or deep bodies of water benefit from moderating effect; (3) plant vines where snow settles most thickly as deep layer of snow can provide insulation for vines
Choice of varieties: (1) resilient against winter freeze (Cab Franc, Riesling), or species that are extremely wind hardy (parents are American and/or Mongolian species
Protect the vine: (1) build up soils around vine graft (hilling up) but doesn't protect trunk or canes/cordons; (2) bury vines (very expensive as labor intensive - China); (3) prune to have several trunks so if killed in winter can be replaced
147
Describe when frosts occur
Cold air below 0ºC (32ºF) collect at ground level,
Cold winds blow across the vineyard after budburst
148
Explain how frost impacts the vineyard
If happens to newly burst buds or young shoots that have a high-water content, it freezes the water, thereby killing the buds and/or shoots. The damage and impact on yields can be enormous.
149
Identify which regions are most vulnerable to frost
Cool climate - vine responds to regular low temps by not growing until mean air temp of 10ºC (50ºF) is reached
Warmer areas vulnerable because vine begins to grow and will be damaged if drop in temp; however, if buds and young shoots are killed, vine may put out more shoots from secondary buds, but these are less fruitful and take longer to ripen
150
Identify the two types of frost
Advective frost
Radiative frost (or inversion frost)
151
Explain why 'advective frost' occurs
Advection frost occurs when very cold, frost-carrying air blows into a vineyard region and displaces warmer air. Unusual in the spring and more associated with winter conditions.
152
Explain why 'radiative frost' occurs
Radiative frost, also known as inversion frost, is a result of heat being lost on still, cool nights. The earth is heated by the sun during the day and releases that heat during the night. The amount of heat released depends on the level of cloud cover. If the air is not impeded by cloud cover a layer of freezing cold air will develop just above the surface of the soil. This layer of cold air is denser than warm air and, therefore, will be trapped beneath a layer of warmer air and cannot escape. This type of first is most likely to damage vines and is the one that can be more easily, albeit expensively, controlled.
153
Explain the options for managing frost risk in the vineyard.
Reduce the risk
Aspersion
Wind machines
Smudge pots and bougies
154
Explain how owner can reduce the risk of frost in the vineyard
Site selection - avoid frost pockets and choose hillsides where cold air can drain away
Delay pruning to postpone bud burst
Choose a late budding variety, e.g., Riesling, Meunier
Train vines off the ground away from the coolest air which is near the ground
Bare soil between vines rather than cover cop, which absorbs more heat during the day and radiates the heat during the night
Leave additional canes on the vines (sacrifice canes) and then remove if there has been no frost damageE
155
Define 'aspersion'
Irrigation sprinklers used or installed specifically for frost protection; as the water freezes around the parts of the plants, it releases latent heat, protecting the plan.
Need to keep going until temp rises and is expensive in terms of equipment and water, but much lower than wind machines or heater so long as cost of water isn't high
Only method to fight advective frosts
156
Explain how wind machines protect a vineyard from frost
Large fans pull warmer air from above down to ground level, thereby raising the temp. Effective when there is an invasion layer, i.e., a warm zone of air 10m above the ground (+3-5ºC (5-9ºF))
157
Identify the pros and cons of wind machines against frost
Investment warranted if there is chance of damaging radiative frost once every 5 years or less
Initial investment is considerable
Helicopters can create the same effect; expensive but may be worthwhile if severe, short-term risk
158
Identify the disadvantages of smudge pots and bougies
High cost of fuel and labor
Low heating efficiency
Contributes to air population
159
Explain how hail can impact the vineyard
Damage and rip young shoots and leaves, as well as ripening games and introduce points of entry for botrytis and other diseases
Impact in current growing season and future growing seasons
Unpredictable in general, although some regions suffer repeatedly, i.e., Argentina and Burgundy
160
Explain how growers can help management the risk of hail
Fire rockets into thunderclouds, seeding them with silver iodine to cause rainfall rather than hail
If experience regular hailstorms, e.g., Mendoza, net the fruit zone, but this also creates shading so can only be used in areas with high levels of sunlight
Have a number of plots in different areas in high-risk areas
Additional cost of crop insurance against hail
Rely on vine being able to reshoot from existing buds if damage caused early in the season
161
Explain how sunburn occurs
Sun-exposed grapes can become sunburned in prolonged hot weather because grape transpiration is limited and therefore less effective than leaf transpiration. As a result, grapes can reach higher temps than leaves and become burnt. Grapes on vines that are water stressed are more at risk.
162
Identify the impact of sunburnt grapes on the vineyard
Sunburn leads to scars on the skin of grapes and, in extreme cases, to eventual death of the grapes.
Sunburn results in browning of the grape, a bitter taste and increased susceptibility to rot (due to skin damage)
Must be removed during sorting, which reduces yields
163
Identify the options for managing the risk of sunburn in the vineyard
At establishment - row orientation and aspect, avoiding east-west row orientation otherwise grapes on south side subject to sun all day, especially intense afternoon sun
Canopy management to limit amount of direct sun exposure; in hot regions, shade the fruit zone
If heatwave forecasted, additional irrigation, where allowed may reduce water stress and, therefore, sunburn
Special agriculture sunscreen spray can be applied or shade grapes with cloth or net
164
Explain why increase in fires
Warmer, dryer weather associated with climate change = increased in fires, esp Australia, California and Chile
165
Identify methods for managing the risk of fire
Establish vineyards away from woodland, pastures, or other crops which could provide fuel for the fire
Limit cover crops and organic mulches which can also provide fuel for the fire
Install fire detectors and sprinklers
Install and maintain water tank
provide employee training for action in event of emergency
166
Define 'smoke taint'
Smokey or plastic aromas in the final wine that come from exposure to smoke during the growing season.
Effect on fruit increases from version onwards.
Aromas compounds in smoke can be absorbed by grapes and then bind with sugars and form aroma-less precursors, which only become aromatic through the fermentation process. Strength of aromas can increase during aging of wine and during bottle aging as further aroma precursor break down and become aromatic
167
Explain how the risk of smoke taint can be managed
Affected musts can be tested analytically and/or by micro-vilifications (to release the smoke aromas) in days leading up to harvest to establish the extent of the problem
Smoke aroma precursors are inside of grapes so hand harvest, gentle or whole bunch pressing, lower fermentation temp and reduced maceration times can reduce uptake of compounds
Flash detente and reverse osmosis can also help, but will not remove the taint completely
168
Identify the factors that a grower is dependent on in the spectrum of pests and diseases that will need to be dealt with
Geographic location of vineyard
Climate of the vineyard
Weather in the growing season
Variety, clone and rootstock
169
Define 'pest'
Pests are organisms that harm the vine and negatively impact the production of grapes
170
Identify the major pests impacting vineyards today
Phylloxera
Nematodes (microscopic worms)
Grape Moths
Spider Mites
Birds
Mammals
171
Define 'phylloxera'
Phylloxera is an aphid-like insect that feeds and lays eggs on the roots of grapevines
172
Describe the impact phylloxera has on the vineyard
Damages roots, reducing the uptake of nutrients and water
Damaged roots susceptible to bacteria and fungi
Spreads quickly through crawling or humans, e.g., roots of young vines, soil, equipment, and irrigation water
173
Identify the symptoms of a vine with phylloxera
Leads first to a weakening of the vine, reducing growth and yield and then death
Vines die of drought in patches that increase in size year by year
Vine roots are covered with insects surrounded by yellow eggs
Swellings on older roots
Pale green leaf falls on under-surface of leaves
Slow, stunted shoot growth and leaf yellowing appears in around three years, plant dies after about 5
174
Explain how the risk of phylloxera can be managed
Plant on sandy soil
Graft on rootstock hybrids of American species
175
Identify the three American vines species that are best against phylloxera
V. berlandieri, V. riparia, V rupestris offer the most protection because they have hard, corky layers that surround the eggs, sealing the wounds and preventing invasion by bacteria or fungi
176
Explain why an American hybrid was needed to address phylloxera
A single American variety caused problems in calcareous soils of Europe because they could not tolerate the lime in the soil.
Vines suffered from chlorosis, which turned the leaves yellow, halted photosynthesis, and reduced yields and quality.
An American hybrid balance level of protection to phylloxera and resistance to lime in the soil.
177
Identify other ways a rootstock can influence the vineyard (WORK ON)
Resistance to phylloxera
Resistance of nematodes
Resistance to drought
Resistance to waterlogging
Vigor
. . .
178
Define 'nematode'
Microscopic worms that live in the soil even if can't be seen with the naked eye
179
Identify the damage caused by nematodes
Some cause damage by feeding off vine roots, significantly reducing yields and vigor - causing a slow, gradual decline
Others transmit viral diseases
180
Identify the two most common nematodes in the vineyard
Root-know nematode causes knot-like growths on the vine and is one of the most widespread.
Dagger nematode spreads the fan leaf virus.
181
Explain how nematodes spread in the vineyard
Already present in soil
Spread by unclean nursery stock, irrigation water, or vehicles
182
Identify the options for managing the risk of nematodes in the vineyard
Can't be eliminated, only managed
Take soil samples and analyze in a lab to determine number and type of
Fumigate soil; although chemicals banned in most regions, can plough in a cover crop of mustard plant, which contains compounds that work as biofumigants, to kill
Nematode-resistant rootstocks are best solution
183
Identify two nematode-resistant rootstocks
Ramsey and Dog Ridge (v. champion)
184
Define 'grape moth'
Species of moths that do damage to vines
185
Explain how grape moths impact the vineyard
Have several generations per season
Attack flowers in spring and grapes later in the growing season
Wounds created are vulnerable to attack from bacteria and fungi, including botrytis
186
Identify the three most common grape moths
Light brown apple moth - Australia
European grapevine moth - S. Europe (imported into Napa in 2009 but declared eradicated in 2016)
Grape berry moth - central and eastern N America
187
Identify the methods for managing the risk of grape moths in the vineyard
Biological controls: (1) bacterium bacillus thuringiensis (produces substances toxic to moths), (2) pheromone capsures to disrupt mating (sexual confusion), (3) natural predators (parasitic wasps, green lacewings, some spider species)
Insecticides
188
Explain how spider mites cause damage in the vineyard
Spider mites, the most detrimental of all mites, feed on the surface cells of leaves, leading to discoloration of the leaves, reduction in photosynthesis, delayed ripening and reduction in yields.
Thrive in dusty conditions and most damaging when vines are water stressed
189
Identify the types of spider mites seen in different regions
Pacific spider mite - most destructive in California
Red spider mite and two forms of yellow spider mites - Europe
190
Explain how the risk of spider mites is managed in the vineyard
Make environment inhospitable by use of water sprinklers and/or cover crops or mulches to reduce dust
Encourage predatory mites (by planting host species)
General pesticides may kill beneficial predatory mites, but specific sprays can be applied to kill only problematic mites - very costly
191
Explain how birds negatively impact a vineyard
Can destroy an entire crop as the grapes ripen
Isolated vineyards that provide the only source of food in an area particularly in danger
Damage allow bacteria and fungi to enter bunches, which leads to rot
192
Identify one species of birds that is an issue in the vineyard
Starlings
193
Explain how the risk of birds can be managed in the vineyard
Netting over vineyards - cost is justified in high value areas (Mornington Peninsula) or where birds a major threat
Bird scarers or noises but need to be rotated regularly
Falcons sometimes used
194
Explain how mammals can damaged a vineyard
Eat shoots, grapes and leaves
Breaks grape skins open, making them vulnerable to rot
Damage structures such as trellising
195
Identify the types of mammals that cause damage in the vineyard
Deer, rabbits, kangaroos, raccoons, wild boar, baboons
196
Explain how the risk of mammals can be managed in the vineyard
Fencing - high enough or sunk low enough into soil to stop burrowing
197
Identify 10 fungal diseases that impact the vineyard
Powdery mildew
Downy mildew
Grey rot
Eutypa Dieback
Phomopsis Cane and Leaf Spot
Esca
Black rot
Black-foot disease
Bot canker
Anthracnose
198
Identify the fungus that causes Powdery Mildew and its starting spot
Erysiphe nectar, commonly called Odium tuckeri
Introduced from N America to Europe mid 1800s
Specific to grapevines
199
Identify the grape varieties that are more susceptible to Powdery Mildew
Chardonnay
Cabernet Sauvignon
200
Identify the grape varieties that are less susceptible to Powdery Mildew
Pinot Noir
Riesling
201
Explain how Powdery Mildew can become a problem in the vineyard
Overwinters in buds and on canes.
Attacks young, green parts of the vine which shows as dull grey patches, turning into black patches as they advance.
Damages young shoots, inflorescences and grapes, reducing yield.
Grapes can be split at version and become targets for other infections.
202
Identify the conditions needed for Powdery Mildew to exist in the vineyard
Growth rate determined by temp with optimum temp around 25ºC (77ºF)
Thrives in shady conditions
Does not require high humidity - can spread in relatively dry conditions, especially in dense, shady canopies
203
Explain how the risk of Powdery Mildew in managed in the vineyard
Keep an open canopy to reduce shade and density of leaves
Apply sulfur to prevent and treat; spray from a couple of weeks after bud burst and up to version; spray early to keep from getting established, i.e. prevent
Systemic fungicides can be effective and, because they penetrate the green tissue and not washed off by rain; however, fungus can become resistant so only a limited number can be made in a year
204
Identify the fungus that causes Downy Mildew and its starting location
Peronospora, a water mold that lives within vine tissue, not on the surface
Introduced from N. America in last quarter of 1800s and common in most wine regions
205
Explain how Downy Mildew impacts the vineyard
Overwinters on fallen leaves
Attacks green parts of the plant, especially young leaves and flowers, thereby reducing yields by defoliating vines. Will see yellow, circular 'oil spots' and then white, downy fungal growth on the underside of leaves
Attacks grapes as well, but not as much of an issue
206
Identify the conditions Downy Mildew needs to exist in the vineyard
Needs rainfall and warm temps (20ºC (68ºF)) to spread
High risk in warm springs and stormy but warm summers
207
Identify the methods for managing the risk of Downy Mildew
Sprays made from copper sulfate to prevent spread, e.g., Bordeaux mixture (Combo of copper sulfate and lime) became standard in 1880s - lasts only until 20 mm rain has fallen. Only option for organic growers, although now concern about buildup of copper in the soil and water, and EU looking to reduce and/or ban
Other fungicides
Good drainage and open canopy that dries quickly to help avoid it developing and spreading
208
Identify the fungus that causes Grey Rot and the starting point
Botrytis cinerea causes Grey Rot
209
Explain how Grey Rot impacts the vineyard
Grapes are vulnerable if there are any points of entry (i.e., rubbed against each other in tight bunches or punctured by birds or insects), leading to whole bunches being attacked
If flowers are affected, fungus stays dormant in grape and re-emerges after veraison
210
Explain how Grey Rot spreads in the vineyard
Spores are typically present in the vineyard and become active in periods of rainfall and high humidity
Very common fungus that occurs widely in nature. Likes wet and damp conditions and thrives where sugar is present.
211
Identify the grape varieties most at risk for grey rot
Those with tight bunches or thin (?) skins
Semillon
Sauvignong Blanc
Pinot Noir
212
Identify methods for managing the risk of Grey Rot in the vineyard
Select grape varieties with small grapes and tick skins so high levels of resistance and protect grapes against other pests
Maintain an open canopy and remove leaves around bunches
Sulfur and copper sprays are ineffective, but other fungicides can work. Apply at key points in season - flowering nearly complete, end of grape formation, bunch closure (i.e., when grapes are large enough so that they touch each other) and version; however, becomes resistant if used regularly
Antagonistic bacteria, e.g., bacillus subtitles and other forms of biological control
213
Define 'Eutypa Dieback'
Trunk disease also called Dead Arm that leads to rotten wood in vines and can affect whole vineyards
214
Explain how Eutypa Dieback impacts the vineyard
Reduces yields significantly and kills vines over 10 year period
Spores are spread by wind over long distances; infection occurs through pruning wounds in moderate temps and especially during rain
effects are evident in spring with affected vines displaying stunted growth and yellow leaves
215
Identify the varieties susceptible to Eutypa Dieback
Grenache
Cab Sauv
Sauv Blanc
216
Identify the regions where Eutypa Dieback is particularly prevalent
Australia
SW France
parts of California
217
Explain how the risk of Eutypa Dieback is managed in the vineyard
Difficult to control, although pruning late and applying fungicide to pruning wounds can be effective
Affected turns can be cut back 5-10 cm beyond visible symptoms and treated with fungicide, affected wood burnt to avoid spores spreading
Some biological controls (bacillus subtitles)
Retrain from a sucker (shoot that grows from base of the vine) left on trunk (which causes a loss of yields for two years) or removing vine and replanting it
218
Identify how Phomopsis Cane and Leaf Spot impacts the vineyard
Prevalent in years with cool and wet springs followed by humidity and moderate temperatures
Infected canes whiten and break off easily; shoots growing from these canes develop brown cracks at their bases; leaves also infected
219
Identify which varieties are more susceptible to Phomopsis Cane and Leaf Spot
Grenache
220
Identify which variety is less susceptible to Phomopsis Cane and Leaf Spot
Cab Sauv
221
Explain how the risk of Phomopsis Cane and Leaf Spot is managed in the vineyard
Fungicides applied 3 weeks after bud burst and then every two weeks if wet conditions continue
Diseased and dead wood removed during pruning and burnt or buried
Canopy mgmt techniques to improve air flow within the canopy
222
Identify Esca
Complex fungal disease caused by a group of organisms in warmer and drier climates, e.g., S Europe and California
223
Explain how Esca impacts the vineyard
Esca enters through pruning wounds
Symptoms include tiger-striping of leaves and spotting inside the wood
Reduces the yield of the vine and leads to its death within a few years
224
Explain how the risk of Esca is managed in the vineyard
There are no chemical controls
Prevent through
sourcing disease-free stock
new, less detrimental pruning techniques
don't prune in the rain
remove pruning promptly
disinfect pruning wounds
Continued research into bacillus subtillis
225
Explain how Back Rot impacts the vineyard
Black rot is impossible to eradicate once present in the vineyard. Controlled by the same spectrum of chemicals used to control other major fungal diseases, e.g., Downy Mildew
226
Identify two bacterial diseases in the vineyard
Pierce's Disease
Grapevine Yellows (group of diseases)
227
Identify where Pierce's Disease originated
Originated on American continent, initially affects southern USA and Central America and is present in California
228
Explain how Pierce's Disease impacts the vineyard
Bacterium lives in sap channels of vines, which it clogs, leading to grape shriveling, dropping leaves, and death of vine between one and five years
229
Identify the symptoms of Pierce's Disease
Exact symptoms unclear so must be tested in lab to determine whether infected
230
Explain how Pierce's Disease is spread in the vineyard
Sharpshooter insect, which as a vector lead to the rapid spread from 1980s on
231
Define 'vector'
An organism that transmits a disease
232
Identify grape varieties more susceptible to Pierce's Disease
Chardonnay
Pinot Noir
233
Explain how the risk of Pierce's Disease can be managed in the vineyard
No chemical control available for bacterium
Control by reducing vectors
- remove vines close to rivers as riverbank habitats for blue-green sharpshooter
- chemical insecticides
- introduce species of wasp that feeds on eggs of sharpshooters
Strict quarantine rules for movement of plants to prevent further spread
Work being done on developing Pierce's Disease resistant vines
234
Explain how Grapevine Yellows are spread in the vineyard
Vectors, including leafhoppers
Nurseries selling untreated, diseased stock
Bacterium also lives on cover crops
235
Identify the most common type of Grapevine Yellow and where it exists
Europe - flavescence doree - spread rapidly through France in second half of 20th century and present in Germany, S. Europe, NY State and, in a different form, Australia
236
Identify the symptoms of Grapevine Yellow
Delayed bud burst
Drooping posture because new shoots fail to become woody
Canopy turning yellow (in white varieties) and red (in black varieties)
Some strains, vine dies, in others, vine recovers
237
Identify the grape varieties most susceptible to Grapevine Yellows
Chardonnay
Riesling
238
Explain how Grapevine Yellows impact the vineyard
Drastically reduced yields and lower quality fruit (high acid and low sugar)
239
Explain how the risk of Grapevine Yellows can be managed
No treatment available
Focus on controlling the vector
- insecticides
- plants that host leaf hoppers, including cover crops, removed
Nursery - bathe pruning wood in hot water to kill
240
Identify two bacterial diseases (other than Pierce's Disease and Grapevine Yellows) that impact the vineyard
Bacterial blight
Crown gall
241
Identify two viruses that impact the vineyard
Fanleaf Virus
Leafroll Virus
242
Define 'Fanleaf Virus'
Longstanding group of diseases (also called Fanleaf degeneration) found around the world
243
Explain how Fanleaf Virus impacts the vineyard
Early shoot growth is stunted
Canes can grow in distorted ways
Leaves are very pale, malformed - can look like a fan
Effects vary widely from very little to losing most of the crop
244
Identify the variety susceptible to Fanleaf Virus
Cab Sauv
245
Explain how Fanleaf Virus is spread
Move to grafted vines following phylloxera and inadvertent use of infected plant material
Dagger nematode
246
Explain how the risk of Fanleaf Virus can be managed in the vineyard
There is no cure and eventually the affected vines will need to be replaced.
Before planting - test soil to check for presence of dagger nematodes and use only virus-tested, clean planting material and nematode-resistant rootstock
As with most viruses, only cure is one of removal and destruction of infected material, fallowing the site for as long as possible and replanting with virus-free plants.
247
Explain how Leafroll Virus is spread in the vineyard
Spread by grafting and mealy bug
248
Identify where the mealy bug is a key pest
S Africa
mediterranean
Argentina
some parts of California
249
Explain how Leafroll Virus impacts the vineyard
Doesn't kill the vine but reduces yields by up to half and negatively affects quality
Slows down the growth of roots and shoots
Surviving fruit may take several additional weeks to ripen and have more acidity, less color and lower sugar levels
Overall health of vine affected as it stores less carbs
250
Identify the symptoms of Leafroll Virus
Typical downward rolling of leaves usually occurs in autumn
Leaves change color in autumn to red for black grapes and yellow for white grapes
Symptoms not always clear, so need lab testing
Some vines and rootstocks carry the virus without any symptoms
251
Explain how a date for harvest is chosen
Trad rule of thumb - 100 days after beginning of flowering
Europe esp based on potential alcohol level: Cool regions 9.5-11% (AOC Petit Chablis requires min 9.5%; Chablis requires 10%, and Bourgogne Blanc requires 10.5%)
Now, climate has warmed and easier to ripen grapes in cooler climates; better viticulture enabling vine to ripen grapes fully, and a focus on aroma and tannin ripeness (sometimes considered more important than optimum sugar ripeness)
Overriding factor is threat of rain in the harvest period (leave on vine in hopes weather will improve or harvest underripe; rain leading to swollen grapes and split grape with threat of grey rot)
252
Explain how it is determined when grapes are ripe
Sugar Levels - amount of sugar measured by handheld refractometer (brix)
Acidity levels
Aroma and tannin ripeness (determined by taste w/ experience)
High tech means (visible or near infrared spectroscopy) - gives multiple readings for sugar, acidity and various other compounds and measures
Tasting grapes still one of most important ways of deciding when. To harvest
253
Define ‘titration’
Method of finding out amount of a substance in a solution by gradually adding measured amounts of another substance that reacts in a known wya
254
Identify the brix level at harvest for dry still wines
Between 19-25 brix, which converts to 11-15% abv
255
Identify the harvest dates for Loire (Chenin Blanc)
Over a period of 4-6 weeks according to style
Early - sparkling
Mid - dry and off-dry
Late - botrytis or late harvest
256
Identify the harvest dates for California (Zinfnadel)
Early to mid-August - White Zin
Sept - Red wine
In hot area, because of uneven ripening, have to determine whether to include shriveled grapes
257
Identify harvest dates for wines with residual sugar
Harvest late to concentrate sugars in the grapes
Botrytized wines often need hand harvesting over several passes through the vineyard
Eiswein or Icewine picked only when temps below -8ºC (18ºF) for Canadian Icewines
258
Explain why some critics believe hang time is detrimental
Some believe detrimental because overly alcoholic and unbalanced wine lacking in natural acidity and having extra-ripe fruit characters, but some critics and consumers enjoy
259
Identify the two harvesting options
Machine Harvested
Hand Harvested (preferred and required)
260
Identify who defaults to machine harvesting
Inexpensive to mid-priced wine and for larger-scale production
Esp when vineyard designed to be machine harvested - even row spacing, turning space at the end of rows, flat land or land with small, regular gradient
261
Identify the exception to the rule that inexpensive to mid-priced wine and for larger-scale production uses machine harvesting
S. Africa because low cost labor
262
Explain how machine harvesting has improved quality of reputation
Select out undesirable fruit by hand before harvesting by machine
Use a bow-rod shaking maching (rather than older machines that beat the vines) - gentler and can be set to be more selective
Invest in very latest machines with optical sorting devices that can crush grapes and add SOX2 to limit oxidation
Rigorous sorting upon arrival, including removal of MOG and unripe and rotten grapes
263
Define ‘MOG’
Matter other than grapes
264
Identified the advantages of machine harvesting
Faster and substantially cheaper in large vineyards (if designed for machines; 1/3 price of hand harvesting)
Avoids issue of lack of availability and unreliability of casual workers
Harvest at night be kept up to 15ºC (59ºF) cooler and therefore in better condition, reduced microbial spoilage and oxidation
Timing of harvest can wait until desired level of ripeness and then carried out quickly
265
Explain how machine harvesting can save costs w/r/t white, fruity wines
Starting the winemaking with cool fruit preserves freshness of fruit aromas and helps to save cost of refrigeration
266
Identify the disadvantages of machine harvesting
Less gentle than hand harvesting
If whole bunches required, cannot use
If wishing to avoid oxidation or extraction of phenolic compounds (delicate white wines)
Rental or ownership is not cost effective for small vineyards
Unsuitable for growers that have several diff varieties ripening at diff times in same plot
Not suitable for steep slopes or vineyards with limited access
Need skilled operator because quality of work dependent on that skill
Competition for rental of machine at best moment of harvest if machine not owned
Purchasing harvester is major investment
267
Explain why hand harvesting might be preferred
Aiming to make premium wines and prefer hand harvesting to remove whole grape bunches from the vines by cutting the stem of each bunch
268
Identify the advantages of hand harvesting
Highly selected at a bunch-by-bunch level and any diseased or under- or extra-ripe fruit removed at point of harvest
Can deal with steeper slopes, irregular rows, and mixed planting in same vineyard
If handled with care and put in small, stackable crates, minimize crushing of grapes and release of juice which would make juice prone to oxidation and microbial spoilage
269
Identify the max weight of small, stackable crates used for hand harvesting
10-15 kilos
270
Identify the disadvantages for hand harvesting
More expensive in med to large vineyards
Reliable work force not always available
Need to train and supervise workforce
More easily carried out during the day where may not be able to avoid high temps, raising chance grapes will be spoiled by microbes or oxidation (can do at night with lights)
271
Identify an example of hand harvesting preferred
France and Italy - cooperatives receive fruit from small-scale growers and use the fruit for large batches of wine (in expensive, high volume)
272
Identify when hard harvesting is required
Premium sparkling wine where whole bunches required for whole bunch pressing
Beaujolais and other wines that will be made by carbonic or semi-carbonic maceration which require whole bunches
Harvesting only botrytis affected bunches (Trockenbeerenauslese Riesling in Mosel)
Steep slopes (Douro Valley) or uneven land
Bush vines because not on a trellis - too much damage to plants and grapes without trellis
