Misc

Question 1

Draw the vine lifecycle

Answer 1

Question 2

Name a vine species tolerance of extreme cold

Answer 2

Vitis amurensis (Russian/Chinese in origin)

Question 3

Name a wine region where it is never cold enough for dormancy

Answer 3

Canary Islands

Question 4

What are the two phases within dormancy

Answer 4

Endodormancy, Ecodormancy

Question 5

What triggers endodormancy?

Answer 5

Endodormancy is triggered by shorter days (photoperiod signal) and cooler temperatures at the end of the growing season.

Question 6

What happens during endodormancy?

Answer 6

So that cell content won’t form damaging ice crystals (and freeze) in cold temperatures, a plant growth regular (Ascorbic Acid) triggers decreases the level of water in various tissues with the process of dehydration through movement of water to intercellular spaces, and accumulation of sugars and protein complexes that bind water and serve as cryoprotectants.

The grapevine will not grow even under the favorable (growing) environmental conditions, such as adequate moisture, long day length, and warm temperatures.

Question 7

What make a grapevine transit from endodormancy to ecodormancy

Answer 7

A minimum number of chilling hours (varies by variety but in range 150-200 hours). A chilling hour is a one spend ABOVE 0C.

Question 8

What is ecodormancy

Answer 8

The second phase of dormancy is called ecodormancy, a phase in which environmental conditions don’t allow the vine to bud break. In this phase, the plant is actually ready to grow, but low temperatures inhibited bud development, therefore in this stage, low-temperature blocks the bud development.

Question 9

What happened in 1956

Answer 9

Big freeze in SW France. Killed off most Malbec which, with the exception of Cahors, was not replanted.

Question 10

Name a grape variety that buds below 10C and one that buds above

Answer 10

Merlot (under), Ugni Blanc (Above)

Question 11

Draw the parts of a flower

Answer 11

Question 12

What limits bud fruitfulness (the number of inflorenscences that will develop)

Answer 12

Shading of compound bud, temperatures low (under 25C), water stress, and nutrient deficiency

Question 13

How many seeds in a grape

Answer 13

Up to four

Question 14

Typical time between busburst and flowering

Answer 14

Around 8 weeks

Question 15

Optimal conditions for pollen germination

Answer 15

Temparatures from 26C-23C.

Question 16

Creates creates sub-optimal conditions for germination

Answer 16

Low temperatures, rain and wind slow down pollen tube growth and can result in irregular fruit set. Hot dry, conditions lead of water stress and can also have a nagative effect.

Question 17

Which grapes more naturally prone to coulure

Answer 17

Grenache, Cabernet Sauvignon, Merlot, Malbec

Question 18

Which grapes more prone to millerandage?

Answer 18

Chardonnay, Merlot

Question 19

Above what mean temperature in last month of grape ripening can lead to too little acid?

Answer 19

21C

Question 20

Below what mean temperature in last month of grape ripening can lead to too much acid?

Answer 20

15C

Question 21

What transports water to the grape

Answer 21

Xylem

Question 22

What transports sugar solution to the grape

Answer 22

Phloem

Question 23

Number of litres of free run juice from a ton of grapes

Answer 23

400-500 Litres

Question 24

Number of litres of press juice per metric ton of grapes

Answer 24

150-200 litres

Question 25

Chemistry: when pressing berries what is extracted that is not in the free run juice, and the impact on the wine

Answer 25

Pressing ruptures the cell walls near the skin and extracts polyphenols and more potassium. The impact of the potassium is to raise the pH of the must. the additional polyphenols leads to extraction of unpleasant bitter tannins.

Question 26

Common use of the late pressings

Answer 26

Make wine vinegar

Question 27

Rootstock mind maps

Answer 27

See pic

Question 28

Which nutrients are required for green growth

Answer 28

N, Ca, P, Mg

Question 29

Which nutrients are required for grape development

Answer 29

K, Mg

Question 30

In chemistry terms what is sunburn

Answer 30

oxidation of the phenolics in the skin

Question 31

In Europe what is the minimum holding period between spraying and harvesting

Answer 31

1 week

Question 32

Traditional number of days to harvest from flowering, and then véraison

Answer 32

100 days from flowering, 60 hdays from véraison

Question 33

Forumula for average growing season temperature

Answer 33

C(max) - C(min) / 2

Question 34

In France óld vine'is legally defined as what age?

Answer 34

30_ years

Question 35

What synthetic chamicals are are allowed and forbidden in organic viticulture?

Answer 35

No synthetic petrochemicals can be used. Synthetic chemicals are allowed if they are produced organically.

Question 36

What are the chemical formulae for Potassium tartrate and wehich form forms crystals most easility

Answer 36

KHT (most likely to crystallise), K2T, (siude notes Tartartic acid is H2T)