Viti 1: The Growing Environment

Question 1

Photosynthesis in a nutshell:

Answer 1

Sunlight energy allows chlorophyll (leaves) to combine water and CO2 to make sucrose, later transformed into glucose and fructose in the vine itself.

Question 2

Glucose gives…

Answer 2

Larger carbohydrates e.g. cellulose (building the vine), tannins, acids and flavour molecules.

Question 3

Vine temperatures:

Answer 3

Dormant below 10 degrees, growth peaks between 22 and 25 degrees. Growth slows above this, as needs outpace its speed of sugar production. Freeze injury begins at -15, serious at -20 and fatal at -25.

Question 4

Sunlight intensity:

Answer 4

Reduces as the angle at which it hits the ground reduces from 90 degrees to 0. Light beams have to travel through greater thickness of atmosphere.

Question 5

Sites facing east:

Answer 5

Rays less scattered in morning as earth has cooled and dust has settled.

Question 6

Sites facing west:

Answer 6

BAD! 1. Sunlight scattered by dust settled after being lifted by warming air. 2. They face damper and cooler weather conditions.

Question 7

Soils on slopes:

Answer 7

Poorer, more coarse and better drained. Moderates vigour. BUT - lifts costs and runs risk of erosion. Isolated hills often best as they avoid descending cold air from main slopes (e.g. hill of Corton, Montagne de Reims).

Question 8

Forests:

Answer 8

Act as windbreaks, store heat and reduce erosion. BUT - increase humidity and decrease temperature of mesoclimate and can harbour birds.

Question 9

Vigorous canopy can:

Answer 9

Reduce flower initiation and berry set (shading), give more acidity (cooling), reduce sugars (humidity and shading) and encourage competition between shoot tips and berries (stunted ripening).

Question 10

Temperature’s impact on yield:

Answer 10

Rate of growth, number of flower clusters produced, their size and the success of setting into berries.

Question 11

Temperature’s impact on quality:

Answer 11

Level of yield, accumulation of sugars, reduction of acidity and development of aromas.

Question 12

Amerine and Winkler’s heat summation system:

Answer 12

1944. Mean temp. for month, subtracting 10 degrees and multiply by number of days in month. Sums are totalled for growing season months to give figures in Growing Degree Days (GDD). 1370, 1370-1650, 1650-1930, 1930-2200 and over 2200. Sunlight, humidity and temp. variability not taken into account - vine growth slows above 30 degrees.

Question 13

Prevailing Australian heat summation system:

Answer 13

Smart and Dry

Question 14

Rainfall requirements:

Answer 14

500mm/year in cool climate, up to 750mm/year in hotter climate.

Question 15

Calculation for rainfall:

Answer 15

1mm of rainfall on 1 square metre is 1 litre.

Question 16

Substance responsible for ‘green’ flavours:

Answer 16

Pyrazines

Question 17

Regions of higher latitude:

Answer 17

Longer days, longer ripening window.

Question 18

Sunshine’s impact on vine:

Answer 18

Bud viability, flower initiation, berry ripening, cane maturation and rate of photosynthesis.

Question 19

Sunshine hours needed for ripe fruit:

Answer 19

A minimum of 1250 hours. Amount of available sunshine will decrease by up to 10% if near to town or city (pollution).

Question 20

Berry scorching most likely:

Answer 20

After leaf stripping or spray application.

Question 21

Annual temp. and altitude:

Answer 21

Mean annual temp. decreases 0.6 deg with every 100 metre rise above sea level. Loss of 105 GDD a year.

Question 22

Soil fertility:

Answer 22

TOSMAWA! Texture, organic matter content, structure, mineral content, air and water availability and acidity/alkalinity.

Question 23

Soil particles:

Answer 23

Diameter measured in mm. CSFSG: clay, silt, fine sand, sand and gravel. 0, 0.002, 0.02, 0.2, 2 and 2+

Question 24

Clay soils:

Answer 24

Hold more moisture, made of small particles. Negatively charged, will hold more minerals. They stay cool, they swell and crack, they damage roots, they get sticky and their structure deteriorates as they’re worked.

Question 25

Loam:

Answer 25

Balance of clay, silt and sand. Clay’s nutrient holding and drainage of sand.

Question 26

Sandy/gravelly soils:

Answer 26

Good drainage and encourage vine to grow deeper roots to find consistent water supplies. Also warm up more quickly.

Question 27

Limestone soil:

Answer 27

Sedimentary, rich in calcium carbonate, alkaline (usually) and free-draining.

Question 28

Chalk:

Answer 28

Like limestone, but less dense. Drains very well.

Question 29

Dolomite:

Answer 29

High in magnesium, sedimentary.

Question 30

Sandstone:

Answer 30

Made up of quartz (compressed sand particles), sedimentary.

Question 31

Shale:

Answer 31

Originally made of clay, soft and sedimentary.

Question 32

Slate:

Answer 32

Shale metamorphosised by high pressures and temps. Harder, less porous and found in Mosel.

Question 33

Granite:

Answer 33

Hard, dense, free-draining, igneous (solidified magma).

Question 34

Volcanic rocks:

Answer 34

Surface lava (Santorini and Madeira).

Question 35

Good soil structure:

Answer 35

Stable particle crumbs of 1-5 mm diameter. Organic matter content 3-10%.

Question 36

Poor soil structure can lead to…

Answer 36

Capping/crusting, puddling (risks erosion) and sieving (clay deposited and causes clogging).

Question 37

Organic matter consists of:

Answer 37

SSCNLM! Sugars, starches, cellulose, nitrogenous compounds, lignin and mineral matter. Breaks down sugars in mineralisation.

Question 38

Humus:

Answer 38

Partially decomposed organic matter. Gives structure, retains nutrients (negatively charged), retains water, swells and shrinks and darkens colour for absorption.

Question 39

Aeration:

Answer 39

Feeds aerobic organisms, harms bad anaerobic organisms, removes CO2 and feeds roots for growth.

Question 40

Compaction:

Answer 40

Can lead to poor rain infiltration and poor soil structure.

Question 41

Nitrogen (N):

Answer 41

Drives biochemical reactions and stimulates photosynthesis. Boosts plant growth.

Question 42

Phosphorous (P):

Answer 42

Aids energy fixation. Encourages root growth and ripening.

Question 43

Potassium (K):

Answer 43

Regulates flow of sugar and water. Encourages ripening.

Question 44

Calcium (Ca):

Answer 44

Regulates cell acidity. Forms cell walls.

Question 45

Sulfur (S):

Answer 45

Forms part of amino acids and enzymes.

Question 46

Magnesium (Mg):

Answer 46

Big part of chlorophyll. Encourages ripening.

Question 47

pH:

Answer 47

Measures concentration of hydrogen ions in soil solution. 4-6.9 is acid, 7.1-8.5 is alkaline. Vine can’t tolerate pH below 5 - aluminium exposed and kills plant.

Question 48

Limestone-rich soils:

Answer 48

High pH. Iron uptake inhibited, chlorosis risk increased.

Question 49

Over-worked soil:

Answer 49

Become more acidic with breakdown of organic material.