The vine Flashcards
(146 cards)
1
Q
What are the two types of buds?
A
- Compound buds: Form one season, break on the next
- Prompt buds: Form and break open in one season; product lateral shoots
2
Q
How can lateral shoots be helpful?
A
- Lateral shoots towards the end of main shoots can produce more leaves
3
Q
How can lateral shoots be unhelpful?
A
- Lateral shoots not at the end of main shoots can impede airflow and shade fruit; can be removed in summer pruning
- Can produce fruit (“second crop”) that ripens later, and thus will be underripe if harvested with main crop (can be removed by green harvesting). Common with Pinot Noir.
4
Q
What is one year old wood?
A
- Shoots from the previous growing season that weren’t removed, and that support compound buds that will release shoots for the growing season
5
Q
What are the five basic stages of the vine growth cycle?
A
- Dormancy
- Budburst
- Shoot and leaf growth
- Flowering and fruit set
- Grape development
6
Q
Dormancy:
* When does it happen (northern hemisphere)?
* What does the vine need during this stage?
* What are adverse conditions during this stage?
A
- November - March
- Temps below 10 C
- Extremely cold temps (-20 C can damage or kill, and -25 C will kill most)
7
Q
Budburst:
* When does it happen (northern hemisphere)?
* What does the vine need during this stage?
* What are adverse conditions during this stage?
A
- March - April
- Average air and soil temps above 10 C
- Adverse: Frost, cold soils
8
Q
What type of climate can have more uniform budburst? What is the consequence for grape ripeness?
A
- Continental, because rapid increase in temps means budburst happens quickly.
- Even budburst increases the likelihood of even ripening.
9
Q
What soils can result in the best budburst in cool climates?
A
Free-draining, because they warm up more quickly than soils that retain water, which leads to quicker budburst in Spring.
10
Q
What is an early budding variety, and what are some examples?
A
It buds slightly below 10 C. Examples:
* Chard
* Pinot Noir
* Merlot
* Grenache
11
Q
What are some examples of late budding varieties?
A
- Sauv Blanc
- Cab Sauv
- Syrah
12
Q
What can a vine grower do to delay budburst?
A
Do winter pruning late
13
Q
Shoot and leaf growth:
* When does it happen (northern hemisphere)?
* What does the vine need during this stage?
* What are adverse conditions during this stage?
A
March - June
Needs:
* Stored carbohydrates
* Warm, sunlight, nutrients, water
Adverse:
* Low carbs (caused by conditions in prior growing season)
* Water stress (limit photosynthesis and nutrient uptake)
14
Q
Flowering and fruit set:
* When does it happen (northern hemisphere)?
* What does the vine need during this stage?
* What are adverse conditions during this stage?
A
May - June
Needs:
* Warm temps (min 17 C) for flowering
* Sunlight on buds, warmth (above 25 C–though Riesling can tolerate cooler), water, and nutrients for bud fruitfulness next season
Adverse:
* Rainy
* Cloudy
* Windy
* Cold temps
15
Q
What is flowering?
A
Opening of individual flowers within an inflorescence.
16
Q
What happens if temps are below 17 C at flowering?
A
Lengthen duration of flowering, which has negative impact on evenness of grape ripening
17
Q
What two types of conditions can interfere with fruit set and why?
A
- Cold
- Rainy
- Windy
(due to poor pollen tube growth)
or
* Hot
* Dry
* Windy
(due to water stress)
18
Q
What is coulure, what are the three potential causes, and which varieties are esp susceptible?
A
Fruit set failure for a high proportion of flowers, caused by an imbalance in carbohydrate levels
Caused by:
* Cold, cloudy conditions
* Hot, arid conditions with high water stress (stopping photosynthesis)
* Vigorous shoot growth diverting carbs from inflorescence (perhaps by very fertile soils, excessive fertilizer, or vigorous rootstocks)
Grenache, Cabernet Sauvignon, Merlot and Malbec all very susceptible
19
Q
What is millerandage, what causes it, and what varieties are more susceptible?
A
- High proportion of seedless grapes that are smaller (lower yield), some of which stay green and unripe (lower quality)
- Cold, wet, windy weather at fruit set
- Chard, Merlot
20
Q
Grape development:
* When does it happen (northern hemisphere)?
* What does the vine need during this stage?
* What are adverse conditions during this stage?
A
June - Sept
Needs:
* Sunlight
* Warmth
* Mild water stress
Adverse:
* Too much water and nutrients (delays ripening)
* Excessive shading of grapes
* Very cold or very hot conditions throughout day and night
21
Q
What are the four stages of grape development?
A
- Early grape growth
- Véraison
- Ripening
- Extra-ripening
22
Q
What are five changes that happen to the grape in early grape growth?
A
- Acids: Tartaric and malic acids increase
- Methoxypyrazines (and some others) increase
- Tannins: Accumulate (promoted by sunshine), very bitter
- Sugar: Low
- Water: Flow into grape via xylem
23
Q
What four things happen during véraison?
A
- Grape growth slows down for a few days (“lag phase”)
- Grape cell walls become more stretchy and supple
- Green-color chlorophyll in skin cells broken down
- Black varieties start to turn red due to synthesis of anthocyanins
24
Q
What are the four general factors that determine the length of the ripening stage?
A
- Variety (early, late, or uneven)
- Climatic conditions
- Management of the vine and vineyard
- Time of harvest
25
What three climactic conditions are best for sugar accumulation and why?
* Max photosynthesis at temps 18-33 C
* Sunshine at least 1/3rd of full
* **Warm, dry** conditions speed grape transpiration, and therefore sugar transport into the grape
26
What conditions of the vine can slow down grape ripening?
* High yields
* Excessive shading of grapes by canopy
* Shoots still actively growing
27
What two categories of factors impact time of harvest?
* Human (wine style, logistics)
* Natural (weather (like rain), onset of disease)
28
What happens to acids post-veraison, and what factors impact this?
* Tartaric acid: Declines due to dilution by addition of water/sugar
* Malic acid: Also declines due to metabolization in respiration, which is quicker when warmer
* Mean temps above 21 C in the final month leads to rapid loss of acidity; mean temps below 15 C can reduce acid loss to unacceptable level (this is why high diurnal range can result in more acidic wines)
29
What impacts methoxypyrazine levels post-veraison?
* Cool temps and limited sunlight (due to excessive shade or cloud cover) can inhibit natural decrease
30
What happens to tannins in black grapes post-veraison, and what factors impact this?
* Decrease slightly
* Polymerize, which makes them less bitter
* Sunshine promotes polymerization
31
What happens during extra-ripening?
* Grapes lose water, which concentrates sugars (most likely in hot, dry, sunny climates)
* Extra-ripe aromas develop
32
What are the five most important nutrients for the vine?
* Nitrogen
* Potassium
* Phosphorus
* Calcium
* Magnesium
33
What are the effects of excessive and insufficient nitrogen?
Excess: too much vegetative growth (focus on shoots, too much shade, etc.)
Too little:
* Low vigor, yellowing of vine leaves
* Grapes with low nitrogen may give ferm problems
34
What are the effects of excessive and insufficient potassium?
Too much:
* Very high: Can cause problems with uptake of magnesium
* High: Can cause high potassium in grapes, linked to high PH
Too little:
* Low sugar accumulations
* Reduced yields
* Poor vine growth
35
What are the effects of insufficient phosphorus?
* poorly developed root system (thus problems taking up water and nutrients)
* reduced vine growth
* lower yields
36
What are the effects of insufficient calcium?
Rare, but has a negative influence on fruit set
37
What are the effects of insufficient magnesium?
* Reduced yields
* Poor ripening
38
What are the four natural factors that affect nutrient availability?
* Nutrients are transported in a water solution, so soil factors that impact water availability also impact nutrients (e.g., clay is better at holding nutrients)
* Soil pH. For example, iron is less available in high pH, leading to chlorosis. Phosphorus is less available in low pH soils.
* Organic nutrient compounds need to be broken down to inorganic compounds (via organisms that live in soil) to be available to vines
* Soil on slopes are often thinner and less fertile
39
What causes chlorosis, what does it look like, and what does it do?
* Iron deficiency, especially in high pH soils (like calcium carbonate such as limestone)
* Leaves turn yellow and photosynthesis stops
* Grape ripening and yields negatively impacted
40
What is soil texture? What soil is finely textured? What soil is loosely textured?
* The proportions of mineral particles of sand, silt, and clay
* Finely textured: high proportion of clay
* Loosely textured: high proportion of sand
41
What is loam?
Soil that has moderate proportions of clay, silt, and sand
42
What are the properties of finely textured soil?
* Effective at holding water and nutrients
* Hard for roots to penetrate and challenging for soil cultivation
43
What are the properties of loose textured soil?
* Poor at holding water and nutrients (i.e., free draining)
* Roots easily grow
44
What is soil structure? What does it determine?
* How the mineral particles form aggregates (crumbs)
* Size, shape, stability of aggregates determine water drainage, root growth, and workability of soil
45
What is humus and why is it good in soil?
* Organic matter formed by partial decomposition of plant and animal material by soil microbes and earthworms
* Spongey texture, large surface area, able to adsorb water and nutrients
* Helps bind soils together; helps retain water and nutrients
46
What does the suitability of soil for viticulture depend on?
* Texture and structure of soil
* How far the roots can penetrate (e.g., sandy soil may be fine if roots can extend over a large area)
* Climate (rain, heat, and light needed for the vine--e.g., free draining soils good for wet areas)
47
What are the WSET temp climate ranges?
1. Cool: 16.5 C GST or below
2. Moderate: 16.5 – 18.5 C
3. Warm: 18.5 – 21 C
4. Hot: above 21 C
48
What are the 5 benefits of grape exposure to sunlight?
a. Development of anthocyanins in black grapes
b. Reduced levels of methoxypyrazines
c. More tannins pre-véraison and more tannin polymerization post-véraison (less bitterness)
d. Increase in favorable aromas and precursors, like terpenes.
e. Warms grapes, which results in loss of malic acid
49
What is the potential negative about grape exposure to sunlight ?
Sunburn
50
How does lower latitude affect sunlight?
* more solar radiation per year on a parcel of land (due to angle and traveling through less atmosphere)
* less sunlight hours during growing season
51
All else being equal, what 5 characteristics will grapes at lower latitude tend to have?
(i) higher levels of sugar
(ii) lower levels of acidity
(iii) riper aromas
(iv) higher but riper tannins,
(v) more color intensity
52
What are the 3 primary impacts of altitude on temp and sunlight?
1. Temps fall by about 0.6 C for every 100 m
2. Sunshine more intense because it travels through less atmosphere and more UV radiation, both of which lead to anthocyanin and tannin synthesis.
3. Often have high diurnal range, because there is less atmosphere to re-radiate heat back to the ground. Can be beneficial for retention of acidity.
53
What is the impact of an east-facing slope?
a. Morning sun, warming when air and soil temps are lowest
b. Especially in cool climates, can extend hours of vine growth and grape ripening
c. Dries out dew more quickly, reducing fungal disease
54
What is the impact of a west-facing slope?
a. Afternoon sun
b. In warm clients, perhaps too hot, with risk of sunburn (not an issue in Western Australian or California, where oceans are to the west)
55
Why is aspect more important at high latitudes? What are examples where this matters?
a. High latitudes have the sun hitting at a low angle, and it is lowest in the spring and autumn
b. Favorable slope and aspect thus extend the growing season
c. Examples of Grand Cru sites in Burgundy and Alsace
56
How do bodies of water induce air movement?
* Cool afternoon breezes, as warm air rises over land, and cool air over the water is pulled in to take its place (helpful in cooling Carneros)
* And the opposite at night (helpful in avoiding frosts in Finger Lakes)
57
Who invented Growing Degree Days (GDD), how is it calculated, and what zones are there?
* Amerine and Winkler (1944); meant for CA
* i. For Celsius [Fahrenheit], subtract 10 [50] (i.e., the temp at which vines will start to grow) from the mean temp of a month in the growing season
ii. Multiply by the number of days in that month
iii. Add together for each month in the growing season (and any months that are negative would not be counted)
* Five bands, from Winkler Zone I (cool) to V (very hot), extended to add more
58
What are the four primary threats of climate change?
* Higher temps lead to greater evapotranspiration, and thus more water needs
* Higher temps speeds up acid/sugar ripening, but not tannins or many aromas (so (i) characteristic aromas lost and (ii) varieties may need to change)
* Heat and drought may cause viticulture to become unviable (e.g., in parts of South Africa or California)
* Greater weather variability, including frequency of extreme weather
59
What are the four weather factors that can change?
1. Rainfall
2. Sunlight
3. Warmth
4. Wind
60
What are examples in style or winemaking changes in response to vintage variation?
* For example, producing more sparkling wine or rosé in cooler years
* Winemaking changes to suit vintage:
a. Must adjustments
b. Greater extraction in warm years to balance higher alcohol levels
61
What is vintage variation?
Differences in the **style**, **quality**, and **yield** of wine produced in a year, due to the weather
62
Given a set amount of rain or irrigation, what 4 factors related to soil and land does the amount of water available to the vine depend on?
* How easily the soil drains
* Water-holding capacity (function of texture and organic matter content)
* Soil depth
* Slope (as there is greater surface runoff from steeper slopes)
63
What are two extreme, opposite examples of where soil qualities impact water available to vines?
* Hawke’s Bay receives 1,000 mm of rain every year and yet needs irrigation because of the extremely free-draining soils.
* Jerez receives 650 mm of rain every year, virtually none during the summer. But the albariza soil (made of clay) has good water retention and releases it slowly to the vines. It also forms a crust that reduces evaporation. No irrigation is permitted or required.
64
What is evapotranspiration rate and what three factors does it depend on?
* Transpiration rate of the vine plus evaporation of water from soil surface.
* Depends on
a. Temperature
b. Humidity
c. Wind
65
In what two situations is reflection of sunlight off water especially important for vines?
a. Good in cool climates with cloudy conditions
b. Especially strong at high latitudes, where the angle of the sun is low
66
What are 3 effects of sunlight, other than on grapes or overall warmth?
i. Any sunlight above one third of full sunlight will not limit photosynthesis (so cloudy days don’t, but fog does)
ii. Sunshine also promotes successful fruit set
iii. Sunshine on compound buds promotes bud fruitfulness in the next growing season
67
What is the Huglin Index (1978) and where is it used?
a. Uses both mean and max temps, as well as increased day length at higher latitudes
b. Split into bands, with grape varieties mapped to bands
c. Widely used in Europe
68
What is the Growing Season Temperature (GST) and what is its advantage?
* Mean temp during the whole growing season, grouped in bands
* Closely correlated to GDD and easier to calculate
* Used by WSET for its climate classifications
69
Who created Mean Temperature of the Warmest Month (MJT) and how is it calculated?
a. Smart and Dry (1980)
b. Mean temp of July (or January), as well as measures of continentality, humidity, and hours of sunshine
c. Six bands, ranging from cold to very hot
70
What is the name of the type of grape that has red-colored pulp?
Teinturier
71
What temps are required for successful fruit set?
Warm (optimal at 26 - 32 C)
72
What are four impacts of wind on vines?
* Can be cooling or warming (e.g., coastal CA or Zonda in Mendoza)
* Reduces fungal disease
* Increases evapotranspiration, so vines need more water
* Can damage vines and trellises
73
What are two options for protecting vines from winds, and what are drawbacks for each?
* natural windbreaks of trees (though they might compete with closest vines)
* fences (require maintenance)
74
What are seven factors that affect temp and sunlight?
* Latitude
* Altitude
* Slopes and aspect
* Proximity to water
* Winds
* Characteristics of soil
* Mist, fog, and clouds
75
What are two characteristics of soil that have an impact on temp?
* Drainage and texture
* Color of soil
76
What is the impact of light soils vs. dark soils when it comes to sunlight and temps?
* Light soils reflect radiation into lower part of the canopy
* Dark soils absorb more energy and re-radiate it at night when cooler
77
When can it be disadvantageous to have light soils?
in warm climates (increasing temp in hottest part of day)
78
When can it be advantageous to have light soils, and what are two examples of where it is?
* increases photosynthesis and grape ripening in cool and cloudy climates or where late-ripening grapes are used
* like chalky in Sancerre and Champagne
79
When can it be advantageous to have dark soils? What is an example where it can be found?
* especially in cool climates or late-ripening grapes, allowing color development and acid degradation to happen at night
* like volcanic in Etna
80
What is the effect of soil drainage for temps that the vine is exposed to?
* Freely draining soils warm up more in spring, leading to earlier budburst
81
What are two benefits for cool climates of free-draining soils?
* It promotes earlier budburst (however, it does increase risk of harm via spring frost)
* Also promotes root growth in the spring (due to increased warmth)
82
In addition to dark-colored soils, what soil is especially effective at absorbing and releasing heat?
Stony soils, esp if underlying soil is slightly damp
83
Where is high diurnal range thought to be good, and why?
* warm or hot climates (like Mendoza or Ribera del Duero)
* it can slow respiration of malic acid and promote formation of anthocyanins (as the day temps are too hot)
84
Where is low diurnal range thought to be good, and why?
* Cool or mod climates (like Mornington Peninsula or Mosel)
* night temps still allow acid degradation and formation of anthocyanins
85
Where can cold nights (below 15 C) be beneficial in cool climates, and why?
* Top sites in Wachau
* Reasons unclear (maybe increase in growing season?)
86
What are two aromas impacted by nightime temps?
a. Warmer nights foster breakdown of methoxypyrazines, which may be good in a cool climate.
b. Cooler nights associated with greater retention of rotundone.
87
What is vine transpiration?
Water diffuses from stomata under leaves, causing water to be pulled up from the soil, through the roots and the rest of the vine.
88
How does lack of water impact photosynthesis?
A lack of water can cause stomata to close partially or fully, which slows or stops photosynthesis due to lack of CO2
89
What are the four basic parts of the vine?
* Shoots
* One-year-old wood
* Permanent wood
* Roots
90
What are the five major structures of shoots?
* Buds
* Leaves
* Lateral shoots
* Tendrils
* Inflorescences/grape bunches
91
What are shoots called after leaves fall and their lignify?
Canes
92
What are the swellings along shoots where other structures are attached?
Nodes
93
What are the lengths between nodes called?
Internodes
94
What is the name of a leaf stalk?
petiole
95
What is the number of inflorescences on each shoot?
varies depending on variety, but usually 1-3
96
What is a fertilized inflorescence?
a bunch of grapes
97
What is an example of a variety with tight bunches, and what is the consequence?
* Pinot Noir
* Higher likelihood of fungal disease due to (i) grape splitting and (ii) lack of air flow through bunch
98
What are four functions of roots?
* anchor vine
* uptake of water and nutrients
* store of carbs
* produce hormones
99
Where in the roots are water and nutrients absorbed?
Root tips, where roots are actively growing
100
Distribution of roots depends on what four factors?
* soil properties
* irrigation
* cultivation
* type of rootstock
101
What is a cutting?
A section of vine shoot that can be planted or grafted, and then will grow as a new plant
102
What are two notable Pinot Noir clones?
* 115: small berries, suitable for high quality red wine production
* 521: higher yields of larger berries, suitable for sparkling wines
103
What is the best known hybrid?
Vidal Blanc, from Ugni Blanc and a member of the Seibel family (with American parentage)
104
Why is mild weather during dormancy harmful?
It may cause early budburst, which then increases risk of frost damage
105
What four steps are involved in flowering?
* Pollen-laden stamens are exposed
* **Pollination**: Pollen grains shed and land on moistened stigma surface
* **Germination**: Each pollen grain produces a pollen tube
* **Fertilization**: The pollen tube penetrates the stigma and then the ovule, delivering sperm cells that fertize the egg therein
106
What is fruit set?
The transition from flower to grape.
Fertilized ovules form seeds (up to four per grape) and wall of ovary enlarges to form skin and pulp.
107
What percentage of flowers will become grapes?
Typically 30%, but can vary from 0-60%
108
How important is temperature during shoot and leaf growth?
Usually not a limiting factor, as photosynthesis optimum temps 18-33 C
109
What are two reasons why sugar accumulation in grapes is faster at warmer temps?
* Optimum photosynthesis conditions
* Increased grape transpiration promotes movement of sugar into grapes via phloem
110
What are optimum conditions for anthocyanin synthesis?
* 15 - 25 C
* plentiful sunlight on grapes
111
What are impacts of El Niño in South America, California, Washington and Oregon, and Australia?
* South America and California
i. More rainfall and risk of hurricanes
ii. Potential for disrupted pollination and fruit set, and excessive vegetative growth
* Washington and Oregon
i. Warmer and drier than normal
* Australia
i. Warmer and drought
112
How often does an El Niño event occur?
Every 3-7 years (extreme events more rarely), perhaps becoming more frequent with climate change
113
What are four vine age segments, and how are vines managed in each?
* First 2-3 years: Remove inflorescences so the vine can focus on growth
* Young vines (up to about 5 years): Low yields because their roots aren’t established
* Max yield between 10-40 years (depending on variety and environmental conditions), after which yield will decrease with vigor
* Very old vines (50 years or more) profitable in super premium areas (like Burgundy or Eden Valley), but not for inexpensive or mid-priced wines
114
What are four theories why old vines make higher quality fruit?
* Better balanced because they are older
* Lower yields increase concentration
* More old wood and thus bigger store of carbohydrates early in growing season or when stressed
* Better vines aren’t grubbed up by growers
115
From the perspective of grape ripening for quality red wines, when is it best for mild water stress to begin?
During early grape growth, prior to veraison
116
What four things happen during grape ripening?
* cells in the grape rapidly expand
* sugar and water accumulate
* acid levels fall
* tannins, color, and a number of aroma compounds and precursors develop
117
* What four parameters does ripeness depend on?
* Which are generally the focus of determining overall ripeness, and why?
* Sugar level
* Acid level
* Profile of aromas/flavors
* Tannin ripeness
The focus is on (i) tannins and (ii) aromas/flavors because sugar and acid can be adjusted
118
* Why do grapes shrivel during extra-ripening?
* What's an example of a variety that is especially shrivel-prone?
* No further import of sugar or water, but grape transpiration continues
* Syrah
119
Why might extra-ripening not be possible?
* Weather (e.g., rain)
* Disease
120
How do vines regulate their temperature?
Transpiration
121
Why do vineyards struggle closer to the poles, in spite of increasing sunlight hours during the growing season?
They are just not warm enough for sugar to accumulate in the grapes (as well as all of the other temperature-dependent steps in grape ripening)
122
In addition to modifying sunlight and warmth, what are four other possible benefits from slopes?
* Shallower, poorer soils
* Better drainage
* Shelter from winds and rain
* Protection from frosts
123
What are two potential disadvantages of slopes?
* Soil erosion (and expense incurred to avoid it, like terracing)
* Inability to use machinery on steep slopes
124
How can valleys change wind?
They can funnel winds, leading to stronger winds
125
How can areas near bodies of water have lower diurnal range?
Cool breezes during the day
126
How do soil temps translate into budburst and shoot growth?
Rising soil temps stimulate starch breakdown in roots, which in turn stimulates budburst and shoot growth
127
When do mists or fog generally occur during the day, and what are three potential impacts on grapes?
Morning
Impacts:
* Reduces solar radiation (possibly reducing photosynthesis)
* Cools vines, slowing sugar accumulation and acid degradation (among other things)
* Increases humidity, increasing fungal disease pressure
128
What are four reasons why vines need water?
* Turgidity (so it doesn't wilt)
* Photosynthesis
* Regulating temperature
* Uptake of nutrients (as water is a solvent)
129
What are 3 possible negative consequences of too much water during the grape ripening period?
* Excess leaves: too much shading and too dense a canopy
* Dilution of sugars in grapes
* Grape splitting (leading to botrytis)
130
What are two possible negative consequences of too little water during the grape ripening period?
* Early onset of grape shrivel
* Reduced ability of grapes to reach desired ripeness level
131
What are two consequences of low humidity in the air?
* Increased evapotranspiration rate, so vines need more water
* Increased grape transpiration, so higher sugar accumulation in grapes
132
What are the three general components of soil?
* geological sediment (weathering of bedrock, moved)
* organic remains
* pores between sediment that contain water and air
133
Why are waterlogged soils harmful?
* Water displaces oxygen in the soil, and oxygen is essential for the respiration of vine roots and soil organisms
* Can lead to reduced vine growth and eventually death
134
How is a region's climate defined?
Temp, sunlight, rainfall, humidity, and wind averaged over time (often 30 years)
135
What is continentality?
A measure of the difference between the annual mean temps of the hottest and coldest months
136
Do old vines always produce better fruit?
No--a young vine in a suitable location and trained and trellised well is likely to produce better wine than an old vine poorly situated or poorly maintained
137
What four things at flowering/fruit set can limit bud fruitfulness in the next growing season?
* Shading of compound buds
* Temps under 25 C
* Water stress
* Nutrient deficiency
138
What is bud fruitfulness?
The number of inflorescences that will develop from a bud
139
What are two examples of rootstocks tolerant of root-knot nematodes, and what is their parentage?
Ramsey and Dog Ridge (both Vitis champini)
140
What are rootstocks that are highly tolerant of drought?
* hybrids of V. rupestris and V. berlandieri
* 110R or 140R
141
What are rootstocks tolerant of high salinity?
* based on V. berlandieri
* 1103P
142
What are rootstocks tolerant of waterlogged soils?
* based on V. riparia
* Riparia Gloire
143
What are rootstocks tolerant of low pH?
* hybrids of V. rupestris and V. berlandieri
* 99R and 110R
144
What are rootstocks tolerant of high pH?
* based on V. berlandieri
* 41B
145
What are low vigor rootstocks?
* based on V. riparia
* 420A and 3309C
146
What are high vigor rootstocks?
* based on V. rupestris
* 140R
