Viticulture Flashcards
Most important NA species?
Labrusca, Riparia, Berlandieri, Rupestris
What is a petiole?
Leaf stalk
Two types of buds?
Compound (latent) or prompt
What is the function of prompt buds?
Lateral shoots - secondary if the primary shoot is damaged
Function of stomata?
Allow photosynthesis to occur in leaves; close if water stressed
How many inflorescence per shoot?
1-3
5 functions of roots
Anchoring, water, nutrients, carbohydrate storage, hormone production
Most common propagation technique?
Cuttings - planting a section of vine shoot to grow into a new plant
What process creates new grape varieties?
Cross fertilisation
When is budburst (northern)
Feb-April
When is Flowering/fruit set
May-June
What is required for dormancy?
Below 10C
Not too cold (below -20)
Not too mild
What is required for budburst?
Average above 10C
No frost/cold soils
What do you plant in high-risk frost areas?
Late-budding varieties - SB, CS, Syrah
How can you delay budburst? Why?
Late winter pruning - spring frost
What is required for shoot/leaf growth?
Stored carbs, warmth/sunlight/nutrients/water; no water stress, low carbs
What causes low stored carbs?
Excessive leaf removal, water stress, mildew, high yields last year
What is required for flowering/fruit set?
Minimum 17C
Sunlight, warmth, water, nutrients
No rain, clouds, wind, cold
Describe coulure
Fruit set fails for most flowers. Ovule fertilisation is unsuccessful.
Caused by low carbs, whether lack of storage or diverted to other shoots
Describe millerandage
High proportion of seedless grapes; grapes are smaller and reduces wine volume; usually lower quality
Caused by cold, wet, windy weather at fruit set
What is required for grape development?
Sunlight, warmth, mild water stress; avoid too much water/nutrients/shading/extreme temperatures
Two main acids in grapes
Tartaric and malic
Why limit water and nutrients during grape development?
They encourage shoot growth rather than ripening
What happens to grapes in veraison?
Cell walls become stretchy and supple
Green chlorophyll is broken down as anthocyanins develop
Best temperature for photosynthesis?
18-33C
Best temperature for increasing anthocyanins?
15-25C
Examples of early ripening/late ripening?
Early: chard/PN; late: CS/Gren
Effects of warm temperatures during grape ripening?
Faster sugar accumulation
Faster malic acid degradation
Effects of sunlight on grape develoment?
Development of anthocyanins
Reduction of methoxypyrazines.
Greater accumulation of tannins pre-veraison
Promotes tannin polymerization after veraison
Decreases malic acid
Temperature difference per 100m altitude increase?
0.6C
Which aspect extends vine growth and ripening?
East (morning sunshine) - dries
Which is better for close water proximity - early-ripening or late ripening?
Early ripening
El Nino - location and effects?
Washington/Oregon and Australia
Warmer temps and drought
Regions known for morning fog?
Sonoma, Napa, Leyda Valley, Sauternes
How much rainfall needed per year?
500mm cool, 750mm warm
Why does a vine need water?
Turgidity, photosynthesis, temperature regulation, nutrient uptake
Function of stomata?
Photosynthesis and transpiration
Results of too much rain in the summer?
Excessive shoot/leaf growth
Dilution of sugar
Grape splitting (rot)
Increased transpiration (increased sugar)
Effect of water-logged soil?
Reduces oxygen, which slows root growth and can kill vine
Characteristics of soil on slopes?
Thin - due to erosion
Lower water/nutrients
Define evapotranspiration
Rate at which water is no longer available;
Combination of vine transpiration and evaporation of water from the soil
Three factors leading to high evapotranspiration rate?
Hot, dry, windy weather
Five most important nutrients?
Nitrogen, Potassium, Phosphorus, Calcium, Magnesium
Importance of Nitrogen?
Vine growth, vigor, grape quality
Importance of Potassium?
Vine growth, regulate water flow
Importance of Phosphorus?
Photosynthesis
Importance of Calcium?
Photosynthesis, structure of plant cells
Importance of Magnesium?
Photosynthesis, grape yields/ripening
Importance of soil pH?
Nutrient availability/uptake
Difference between organic and inorganic compounds, and why is it important?
Organic contains carbon; vines cannot uptake carbon, nutrients need to converted to inorganic compounds
What is mineralization?
The conversion of organic compounds to humus or other available inorganic compounds
Role of humus?
Increase soil ability to hold nutrients/water
Binds soil together
Most important characteristics of soil?
Texture (proportion of mineral particles)
Structure (how mineral particles aggregate)
When does soil radiate warmth?
Light-colored: During the day, maximizing sunlight
Dark-colored: At night, moderating diurnal changes
What determines climate?
Annual temperature pattern, sunlight, rainfall, humidity, wind
Ways to measure climate zones?
GDD - Growing Degree Days (Winkler Zones)
Huglin Index - used in Europe
Mean Temp of Warmest Month - July/January
Growing Season Temperature - basically GDD
Define Maritime climate.
Low differences between summer/winter
Rainfall evenly spread throughout year
Ex. Bordeaux, Champagne, Loire
Define Mediterranean climate
Low annual differences between summer/winter
Rainfall in winter, dry summers
Ex. Napa, Coonawarra, Stellenbosch
Define Continental climate
Extreme summer/winter differences
Short summers, fluxuating spring/fall
Ex. Burgundy, Alsace
Temperature ranges for climates
Cool - below 16.5
Moderate - 16.5-18.5
Warm - 18.5-21
Hot - above 21
Define continentailty
Difference between annual mean temperature of hottest and coldest months
Effects of climate change
More evapotranspiration/water stress Earlier/faster vine cycle Less acidity more sugar Change in aroma compounds Extreme weather events
Advantages of Conventional Viticulture?
Mechanization, reduction of competition, tend to specific needs (irrigation/hazards/nutrients/water)
Increased yield
Minimized cost
Disadvantages of Conventional Viticulture?
More prone to pests/disease
Nutrients depleted
Chemicals lead to environmental damages
Characteristics of Conventional Viticulture?
Creating a monoculture
Raised production level
Reduced labor
Using mechanization, chemicals, irrigation, clonal selection, fertilizers
Characteristics of Sustainable Viticulture?
Focusing on environment
Protect natural ecosystem
Maintain biodiversity
Minimize chemicals
Define IPM
Integrated Pest Management
Setting thresholds for implementing control measures
Advantages to Sustainable Viticulture?
Attention to economic, social, and environmental impact
Using scientific understanding to minimize interventions
Cost saving
Disadvantages of Sustainable Viticulture?
Term not protected, no set standards
Bar can be set too low
Characteristics of Organic Viticulture?
Using compost to break down soil/provide nutrients
Cover crops (not monoculture)
Natural fertilisers only (sulfur, copper sulfate)
Natural predators/sexual confusion pheromone tags
Certifying organization for organic?
IFOAM - International Federation of Organic Agriculture Movements
Advantages of Organic/Biodynamic Viticulture?
Improvement of soil and vine health
Saving on chemical cost
Elimination of synthetic chemicals
Disadvantages of Organic/Biodynamic Viticulture?
Possible yield reduction
Metal build-up in soil from copper
Cost/time of certification
What are preparations?
Homeopathic remedies used in biodynamic viticulture to fertilize soil and prevent diseases and pests
Certification body for Biodynamic Viticulture?
Demeter
Define Precision Viticulture
Collecting data from sensors to make plot or row based decisions
Advantages of Precision Viticulture?
Detailed understanding of variations, and the ability to tailor as neede
Aim to improve yields and quality
Disadvantages of Precision Viticulture?
High initial cost
Trained staff to understand data analysis
Factors to consider when establishing a vineyard?
Site Selection
Soil preparation
Planting materials
Factors in site selection?
Fertility Climate/Topography Price GI Layout
Important considerations for vineyard location?
Ease of access to winery
Ease of access to market/distribution/customers
Ease of access to labor/supplies
Relevance of GI per cost/what you want to make
Pre-planting analysis of soil includes what components?
Drainage Structure Mineral composition Pests Other plants
What is subsoiling?
Breaking down of the soil to increase drainage/cultivation
How to combat low soil pH/acidic soils?
Plough in lime
Climate considerations when choosing grape variety to plant?
Early/late budding Early/late ripening Drought tolerance Disease resistance Vigor Winter hardiness
Style/preferential considerations when choosing grape variety to plant?
Style of wine Yield Cost Law Availability Market demand
Besides phylloxera, when might you choose to graft rootstock?
Pest-resistant (root-knot nematodes) Drought-resistant Water-log resistant Salinity resistant Low or high pH Moderate/enhance vigor
Advantages of organic fertilizers?
Cheap/free
Easily accessible
Gradual uptake
Disadvantages of organic fertilizers? (Aka advantages of switching to inorganic)
Need to be incorporated into soil (labor)
Bulky, expensive to transport/spread
Not tailored to specific needs
What is cultivation?
Controlling weeds by ploughing soil and disrupting roots. Incorporates organic fertilizer
Three types of herbicides?
Pre-emergent
Contact - kills green part of weed
Systemic - uptake through leaves, kills plant
Aims of canopy management?
Maximize light effectiveness
Reduce shade
Ensure uniform ripening
Promote balance between vegetative/reproductive functions
Arrange in order to promote machine/manual labor
Air circulation
Effect of shade on latent buds?
More vegetative structures grow rather than reproductive
Effects of sunlight on grape development?
Increased sugar through greater photosynthesis Increased tannin/polymerisation Increased anthocyanins Decreased malic acid Decreased Methoxypyrazines Increased aroma precursors/compounds
When does the vine shift nutrients from green to grapes?
Veraison
Long-term effects of under cropping?
Vine enters vegetative cycle, decreased bud fruitfulness
Long-term effects of over-cropping?
Vine weakens, decreased bud fruitfulness
Examples of canopy management?
Vine training, winter pruning, vine trellising, vigour management (Fertilisation/irrigation/cover crops), summer pruning
Factors to decide trellising methods?
Vigour, topography, mechanization
Describe bush vines and their relevance.
Head-trained, spur-pruned
Simple, inexpensive
Natural shading from shoots - great for hot/sunny regions
Not for rainy conditions or when mechanization is desired
When to use VSP?
Low/moderate vigor
What is Guyot training?
VSP with replacement cane-pruned vines
Name three complex training systems and why they would and would not be used.
Geneva Double Curtain, Lyre, Scott-Henry
Used for high vigor to spread out canopy
Difficult to manage/mechanize
Examples of summer pruning?
Disbudding, shoot removal, shoot positioning, pinching, shoot trimming, leaf removal, crop thinning/green harvesting
Possible results of rainfall during fruit set?
Coulure or millerandage
Temperature difference for hillside vs valley floor during winter?
5C
Reducing frost risk:
Site selection (avoid frost pockets) Delayed winter pruning Late-budding varieties NO cover crops High training
Combating frost:
Aspersion (water sprinklers) Wind machines (pull warmer air down) Helicopters Gas burning heaters (smudge pots) Wax candles (bougies)
Hail protection:
Rockets fired into thunderclouds
Netting
Crop insurance
Separate vineyard sites
Effects of sunburned grapes?
Browning skin, bitter taste, susceptibility to rot
Fire protection:
Avoid cover crops (kindling)
Install fire detectors and sprinklers
Install/maintain a water tank
Provide employee emergency training
Describe a phylloxera infestation:
Feeds/lay eggs in roots
Transported by humans on equipment, roots, and irrigation
Damage to roots causing nutrient and water uptake issues and increased backteria/fungi
Describe effects of nematodes:
Feed on roots, reducing yields and vigor
Transmit viral diseases (e.g. fanleaf virus)
Cannot be eliminated in a vineyard, only managed
Which pests feed on leaves?
Spider mites
Two main types of mildew and how to prevent?
Powdery & Downy
Sullfur sprays
Open canopies
What is trunk disease?
Eutypa dieback
Fungal infection that spreads by wind
Most common bacterial disease and its effect?
Pierce’s Disease
Clogs sap channels, leads to vine death
Time frame from flowering to harvest?
100 days
When are grapes considered ripe enough for harvest?
19-25 Brix
Acidity level - titration or pH
Aroma/tannin ripeness
Advantages to machine harvest?
Faster/cheaper/less labor
Harvest at night, better condition
Correct harvest time (no need to start early for manual labor)
Disadvantages to machine harvest?
No steep slope access Need skilled operator Less gentle Cost of machine No whole bunch
When is hand harvesting required?
Premium sparkling wines
Beaujolais/carbonic maceration style
Bunch-by-bunch - Botrytis
