WSET DIPLOMA D1 WEST DIPLOMA| LATEST
QUESTIONS AND
ANSWERS 2026/2027 LATEST UPDATE
Define lignify
Green shoots become woody and rigid, they are then called canes Where do buds
form?
between the leaf stalk (petiole) and the stem
Define the two types of buds
- Compound buds (form in one growing season and break open the following growing season,
producing main shoots; typically a primary, secondary, and maybe tertiary)
- Prompt buds (form and break open same season, form lateral shoots)
What is the main function of lateral shoots? When are they desirable/undesirable? - to allow the
plant to carry on growing if the tip of the main shoot has been damaged or eaten
- can provide an additional source of leaves for photosynthesis (useful if the laterals are near the
ends of the main shoots)
Growth of laterals nearer the base of the main shoot can be undesirable as they impede air flow
and can shade the fruit too much
Most important N American grape species
Vitis labrusca, Vitis riparia, Vitis berlandieri and Vitis rupestris Four
main sections of a grape vine
Page | 1
,the main shoots, one-year-old wood, permanent wood and the roots What
comprises the canopy of a vine?
The main shoots and all of their major structures - stem, buds, leaves, lateral shoots, tendrils
and inflorescences/grape bunches What do the main shoots grow from, and when?
The main shoots on the vine grow in spring from buds retained from the previous year Where are
carbohydrates stored in a vine?
Stems, trunks, roots
What is second crop?
Lateral shoots often produce inflorescences, which can be known as a 'second crop' What is green
harvesting?
Removal of second crop during summer Define one-
year-old wood
the main shoots from the last growing season that were kept at pruning, supports
compound buds; cane or spur Define permanent wood
woody parts of the vine that are older than one year, including the trunk where are most
roots found?
top 50cm of soil what distinguishes
PN clone 115?
low Y, small grapes, good for high Q red wines what
distinguishes PN clone 521?
high Y, bigger grapes, good for sparkling wine production When is leaf
fall and dormancy?
Nov-March
When is budburst?
March-April
When is shoot and leaf growth?
March-July
When is flowering and fruit set?
,May-June
When is grape development?
June-Oct
When is harvest?
Sept-Oct
How does the vine support itself during dormancy?
starch in the roots, trunk, and branches
Below what temp can vines be severly damaged? die?
-15C, -25C
What factors determine the timing of budburst?
- air temp (>10C)
- soil temp (higher encourages earlier budburst)
- variety
- human factors (e.g. winter pruning late -> later budburst) Why is high continentality good for
budburst? marked differences in temp can result in uniform budburst Chard, PN, Merlot,
Grenache are budding early
SB, Cab, Syrah are budding
late (need higher temps) what
determines the vigor of a vine?
rate of shoot growth when does the fastest rate of shoot growth
typically occur?
between budburst and flowering what could cause low carb levels in
roots, trunk, and branches? - excessive leaf removal
- water stress
- mildew
- high crop loads in prev season what can slow initial shoot growth rates?
Page | 3
, low carb levels what supports shoot growth in
later stages?
photosynthesis at what point of the vine growing cycle is water stress not
desired?
late stages of shoot growth (can affect photosynthesis) what can
stunted shoot growth lead to?
- weak shoots
- reduction in leaf number/smaller leaves - inflorescences that do not flower properly what can
limit bud fruitfulness?
- low temp (<25C)
- water stress
- shading - nutrient deficiency how long after budburst does flowering typically take place?
8 weeks (temp dependent) why are warm conditions (>17C)
desired during flowering?
speeds up flowering (occurs within a few days) what % of
flowers become grapes typically?
30%
what temp does pollen germination require?
26-32C what negatively affects pollen tube
growth?
wind, rain, cold temps; wind, water stress, hot temps define
coulure
A condition of the grape bunch in which fruit set has failed for a high proportion of flowers.
This occurs when ovule fertilisation is unsuccessful, and therefore no grape develops. what
causes coulure? imbalance in carb levels due to:
- low photosynthesis rates
- vigorous shoot growth diverting carbs (very fertile soils, vigorous rootstocks) define
millerandange
QUESTIONS AND
ANSWERS 2026/2027 LATEST UPDATE
Define lignify
Green shoots become woody and rigid, they are then called canes Where do buds
form?
between the leaf stalk (petiole) and the stem
Define the two types of buds
- Compound buds (form in one growing season and break open the following growing season,
producing main shoots; typically a primary, secondary, and maybe tertiary)
- Prompt buds (form and break open same season, form lateral shoots)
What is the main function of lateral shoots? When are they desirable/undesirable? - to allow the
plant to carry on growing if the tip of the main shoot has been damaged or eaten
- can provide an additional source of leaves for photosynthesis (useful if the laterals are near the
ends of the main shoots)
Growth of laterals nearer the base of the main shoot can be undesirable as they impede air flow
and can shade the fruit too much
Most important N American grape species
Vitis labrusca, Vitis riparia, Vitis berlandieri and Vitis rupestris Four
main sections of a grape vine
Page | 1
,the main shoots, one-year-old wood, permanent wood and the roots What
comprises the canopy of a vine?
The main shoots and all of their major structures - stem, buds, leaves, lateral shoots, tendrils
and inflorescences/grape bunches What do the main shoots grow from, and when?
The main shoots on the vine grow in spring from buds retained from the previous year Where are
carbohydrates stored in a vine?
Stems, trunks, roots
What is second crop?
Lateral shoots often produce inflorescences, which can be known as a 'second crop' What is green
harvesting?
Removal of second crop during summer Define one-
year-old wood
the main shoots from the last growing season that were kept at pruning, supports
compound buds; cane or spur Define permanent wood
woody parts of the vine that are older than one year, including the trunk where are most
roots found?
top 50cm of soil what distinguishes
PN clone 115?
low Y, small grapes, good for high Q red wines what
distinguishes PN clone 521?
high Y, bigger grapes, good for sparkling wine production When is leaf
fall and dormancy?
Nov-March
When is budburst?
March-April
When is shoot and leaf growth?
March-July
When is flowering and fruit set?
,May-June
When is grape development?
June-Oct
When is harvest?
Sept-Oct
How does the vine support itself during dormancy?
starch in the roots, trunk, and branches
Below what temp can vines be severly damaged? die?
-15C, -25C
What factors determine the timing of budburst?
- air temp (>10C)
- soil temp (higher encourages earlier budburst)
- variety
- human factors (e.g. winter pruning late -> later budburst) Why is high continentality good for
budburst? marked differences in temp can result in uniform budburst Chard, PN, Merlot,
Grenache are budding early
SB, Cab, Syrah are budding
late (need higher temps) what
determines the vigor of a vine?
rate of shoot growth when does the fastest rate of shoot growth
typically occur?
between budburst and flowering what could cause low carb levels in
roots, trunk, and branches? - excessive leaf removal
- water stress
- mildew
- high crop loads in prev season what can slow initial shoot growth rates?
Page | 3
, low carb levels what supports shoot growth in
later stages?
photosynthesis at what point of the vine growing cycle is water stress not
desired?
late stages of shoot growth (can affect photosynthesis) what can
stunted shoot growth lead to?
- weak shoots
- reduction in leaf number/smaller leaves - inflorescences that do not flower properly what can
limit bud fruitfulness?
- low temp (<25C)
- water stress
- shading - nutrient deficiency how long after budburst does flowering typically take place?
8 weeks (temp dependent) why are warm conditions (>17C)
desired during flowering?
speeds up flowering (occurs within a few days) what % of
flowers become grapes typically?
30%
what temp does pollen germination require?
26-32C what negatively affects pollen tube
growth?
wind, rain, cold temps; wind, water stress, hot temps define
coulure
A condition of the grape bunch in which fruit set has failed for a high proportion of flowers.
This occurs when ovule fertilisation is unsuccessful, and therefore no grape develops. what
causes coulure? imbalance in carb levels due to:
- low photosynthesis rates
- vigorous shoot growth diverting carbs (very fertile soils, vigorous rootstocks) define
millerandange
