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Hort/VE 113 Fall 2012Session 5 -Grape Growing:

climate and environment

Introduction to Vines and Wines

climate and environment

Climate terminology• Climate: the average course or condition of

the weather at a place usually over a period of years as exhibited by temperature, wind velocity, and precipitation.

• Mesoclimate: the climate of a vineyard site; up to a region; influenced by prevailing winds, proximity to water.

• Microclimate: the climate of the grapevine canopy.

Meso Climates

• Meso– sites within a region– air drainage, soil, water table, slope,

aspect orientationaspect, orientation– Small end: an extensive vineyard – Large end: a region– Note: there are many

Meso climates possible in a given region

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Micro climates

• Micro– From the scale of inches to the scale of a

few hundred yards

– From the scale of a leaf to the scale of a vineyard.

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Important climatic characteristics• Sunshine• Heat accumulation (growing degree days)• Length of growing season (number of

frost-free days)y• Cold dormant “chilling” period• Absolute minimum temperature• Humidity• Rainfall during growing season

American Viticultural Areas “AVA’s”

• Concept of AVA’s—– Federally recognized growing regions –

American Viticultural Areas

– Designed to give you a geographic and climatological pedigree for the wine coming from that AVA

– Also called “Appellations”

The AVAs of WA• Puget Sound• Red Mountain• Walla Walla Valley• Yakima Valley

• Columbia Gorge• Wahluke Slope• Snipes Mountain• Lake Chelan• Yakima Valley

• Horse Heaven Hills• Rattlesnake Hills

• Lake Chelan• Columbia Valley• Pending: Naches

Heights; Ancient Lakes

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AVA’s were established to help people try to guess the properties of wines without tasting them.

• e.g., If you bought a nice Pinot Noir from one vineyard in the Puget Sound,

h b bl f you might be able to assume some of the characteristics of another Pinot from another winery in the same AVA.

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Sunlight• Desirable regardless of which varieties

are grown or the end use• Required for photosynthesis (production

of carbohydrates)f y )• Heats fruit and accelerates ripening• Stimulates development of fruitful buds• Helps dry foliage and fruit – reduces

disease

Heat Accumulation• Growing degree days (GDDs): used to predict

development of crop and determine where grapes will grow

• GDDs (base 50˚F) = average daily temperature – 50 for a given 24 hour period:

• Average the min and max temps and subtract 50 Average the min and max temps and subtract 50 degrees

• High of 60 low of 50:• 60+50 divided by 2 = 55• 55-50 = 5 GDD• Counted from April 1 to October 31st.

www.weather.wsu.edu

Average air temp (F) 2 Sept 2008

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Prosser, WA GDDs Base 50

GDD Calculation

Wine grapes need high GDDs to accumulate sugar in fruit• >2500(F˚) preferred for red varieties:

C b t S i M l t M lb– Cabernet Sauvignon, Merlot, Malbec• >1900 preferred for white varieties

– Pinot Noir, Pinot Gris, Riesling, Gewurztraminer, Muscat, Chardonnay

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Classification by Maturity

Group GDD (C.) Red varieties White varieties

1 1050 Madeleine Angevine

2 1100 Blue Portuguese Chasselas, Muller -Thurgau, Pinot gris

3 1150 Pi i M i GGewurztraminer,

S l Ch d

Growing degree days (GDD, 1 April - 31 October, base temperature 10°C) required to reach acceptable maturity

3 1150 Pinot noir, Meunier, Gamay Sylvarer, Chardonnay, Sauvignon blanc

4 1200 Malbec, Zinfandel, Pinotage Semillon, Muscadelle, Riesling

5 1250 Merlot, Cabernet franc, Syrah, Cinsaut, Barbera, Sangiovese Chenin blanc

6 1300 Cabernet Sauvignon Colombard, Palomino

7 1350 Aramon, Carignan, Grenache Muscat of Alexandria, Ugni blanc

8 1400 Tarrango, Terret noir Clairette, Grenache blanc

Length of growing season

• Number of continuous days without frost

• Frost can freeze buds in the spring, eliminating cropeliminating crop

• Frost can cause leaves to drop early, limiting carbohydrate reserves that are stored over winter

Chilling period

• Required for buds to “break” in spring– Accumulated degrees below a certain threshold

• Not usually an issue in the temperate climates

• Makes tropical viticulture difficult

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Absolute minimum temperature• Cold temperatures can

kill buds, canes, trunks, even entire vines!

• High variation in cold h di hardiness among species and cultivars

• Makes temperature moderation by water (oceans, large lakes) important

• -10˚F damages most V. vinifera varieties

Continentality = effects of bodies of water, slope, elevation on wind generation

The wind can act to protect grapes from freezing, overheating and can remove excess moisture

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Humidity and rainfall

• Encourage fungal diseases such as powdery mildew and downy mildew

• Rainfall sometimes provides more water than desirablewater than desirable

• Dry climate with irrigation reduces disease and allows the grower to stress the vine at the appropriate time

Soils

• Well drained generally best– Mixtures of sand, gravel, organic matter

• Drainage can be improved with drainage tiletile

• Many wines benefit from the mineral content of the soil– sometimes chalky

• Rootstocks are selected for soil characteristics (texture, pH)

Soil typesAlluvial - A combination of clay, silt, sand and gravel that forms over

time from mineral deposits left by running water.Granite - A hard and granular rock with a high content of crystals,

particularly quartz.Jory - A volcanic soil composed mostly of basalt, which is in turn a hard

and dense soil that often has a glassy appearance.Limestone or Chalk - A soft soil made primarily from fossilized

seashellsseashells.Loam - A crumbly mixture of clay, sand and silt.Marl - A crumbly mixture of different clays as well as calcium and

magnesium carbonates with fossilized shells mixed in as well.Sandstone - A combination of silica and sand compacted together by

pressure and time.Tufa - A mix of silica, calcium carbonate and sometimes volcanic ash

that has been deposited over time by streams, lakes and other water sources.

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“Terroir”A French term (much discussed) for the total natural environment of any viticultural site

Major components have been described:

SoilMacro-,meso-, and microclimates

Determinants of terroir include:

• Climate-temperature and rainfall• Sunlight energy-received per unit of

“Terroir”

g gy pland area

• Topography-altitude, slope, and aspect• Geology – more on this later• Hydrology –soil water relations

Fine wines• All involve matching the grape variety to the local “terroir”

• Viticulturists have learned how to manage the vines to achieve the best results for that particular location

• Certain climate years yield outstanding “vintages”

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Introduction to Vines and Wines

Hort/VE 113 Fall 2012Sessions 6 & 7-Grape Growing

pruning and training

Lesson Objectives:

Learn the importance ofpruning in vine and crop management

Understand how pruning affects l d d t ti thcrop load and vegetative growth

Understand how pruning levelsaffect fruit quality

Concepts of Pruning

What is pruning? What is the difference between pruning and training?

Pruning is the removal of unwanted wood f h i d or parts of the vine…and

Training is the establishment of the permanent vine structure or form.

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1. Establish and maintain vine structureand cropping

2 Distribute crop load

Why prune?

2. Distribute crop load

3. Control and adjust crop load

4. Maintain or control vegetative growth

The principal objective of pruning is to maintain a balance between fruiting (crop load) and vegetative growth (canopy)