WSET
WSET Diploma D1 Exam Study
Questions and Answers 2025
Most important North American grape species -Correct Answer ✔Vitis labrusca, Vitis
riparia, Vitis berlandieri and Vitis rupestris
Four main sections of a grape vine -Correct Answer ✔the main shoots, one-year-old
wood, permanent wood and the roots
What comprises the canopy of a vine? -Correct Answer ✔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? -Correct Answer ✔The main shoots on
the vine grow in spring from buds retained from the previous year
Where are carbohydrates stored in a vine? -Correct Answer ✔Stems, trunks, roots
Define lignify -Correct Answer ✔Green shoots become woody and rigid, they are then
called canes
Where do buds form? -Correct Answer ✔between the leaf stalk (petiole) and the stem
Define the two types of buds -Correct Answer ✔- 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)
- Prompt buds (form and break open same season, form lateral shoots)
What is the main function of lateral shoots? When are they desirable/undesirable? -
Correct Answer ✔- 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)
What is second crop? -Correct Answer ✔Lateral shoots often produce inflorescences,
which can be known as a 'second crop'
- 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
What is green harvesting? -Correct Answer ✔Removal of second crop during summer
WSET
,WSET
Define one-year-old wood -Correct Answer ✔the main shoots from the last growing
season that were kept at pruning, supports compound buds; cane or spur
Define permanent wood -Correct Answer ✔woody parts of the vine that are older than
one year, including the trunk
where are most roots found? -Correct Answer ✔top 50cm of soil
what distinguishes PN clone 115? -Correct Answer ✔low yield, small grapes, good for
high quality of red wines
what distinguishes PN clone 521? -Correct Answer ✔high yield, bigger grapes, good for
sparkling wine production
When is leaf fall and dormancy? -Correct Answer ✔Nov-March
When is budburst? -Correct Answer ✔March-April
When is shoot and leaf growth? -Correct Answer ✔March-July
When is flowering and fruit set? -Correct Answer ✔May-June
When is grape development? -Correct Answer ✔June-Oct
When is harvest? -Correct Answer ✔Sept-Oct
How does the vine support itself during dormancy? -Correct Answer ✔starch in the
roots, trunk, and branches
Below what temp can vines be severly damaged? die? -Correct Answer ✔-15C, -25C
What factors determine the timing of budburst? -Correct Answer ✔- 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? -Correct Answer ✔marked differences in
temp can result in uniform budburst
what determines the vigor of a vine? -Correct Answer ✔rate of shoot growth
when does the fastest rate of shoot growth typically occur? -Correct Answer ✔between
budburst and flowering
WSET
, WSET
what could cause low carb levels in roots, trunk, and branches? -Correct Answer ✔-
excessive leaf removal
- water stress
- high crop loads in prev season
what can slow initial shoot growth rates? -Correct Answer ✔low carb levels
what supports shoot growth in later stages? -Correct Answer ✔photosynthesis
at what point of the vine growing cycle is water stress not desired? -Correct Answer
✔late stages of shoot growth (can affect photosynthesis)
what can stunted shoot growth lead to? -Correct Answer ✔- weak shoots
- reduction in leaf number/smaller leaves
- inflorescences that do not flower properly
what can limit bud fruitfulness? -Correct Answer ✔- low temp (<25C)
- water stress
- shading
- nutrient deficiency
how long after budburst does flowering typically take place? -Correct Answer ✔8 weeks
(temp dependent)
why are warm conditions (>17C) desired during flowering? -Correct Answer ✔speeds
up flowering (occurs within a few days)
what % of flowers become grapes typically? -Correct Answer ✔30%
what temp does pollen germination require? -Correct Answer ✔26-32C
what negatively affects pollen tube growth? -Correct Answer ✔wind, rain, cold temps;
wind, water stress, hot temps
define coulure -Correct Answer ✔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? -Correct Answer ✔imbalance in carb levels due to:
- low photosynthesis rates
- vigorous shoot growth diverting carbs (very fertile soils, vigorous rootstocks)
define millerandange -Correct Answer ✔A condition of the grape bunch in which there is
a high proportion of seedless grapes.
WSET
WSET Diploma D1 Exam Study
Questions and Answers 2025
Most important North American grape species -Correct Answer ✔Vitis labrusca, Vitis
riparia, Vitis berlandieri and Vitis rupestris
Four main sections of a grape vine -Correct Answer ✔the main shoots, one-year-old
wood, permanent wood and the roots
What comprises the canopy of a vine? -Correct Answer ✔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? -Correct Answer ✔The main shoots on
the vine grow in spring from buds retained from the previous year
Where are carbohydrates stored in a vine? -Correct Answer ✔Stems, trunks, roots
Define lignify -Correct Answer ✔Green shoots become woody and rigid, they are then
called canes
Where do buds form? -Correct Answer ✔between the leaf stalk (petiole) and the stem
Define the two types of buds -Correct Answer ✔- 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)
- Prompt buds (form and break open same season, form lateral shoots)
What is the main function of lateral shoots? When are they desirable/undesirable? -
Correct Answer ✔- 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)
What is second crop? -Correct Answer ✔Lateral shoots often produce inflorescences,
which can be known as a 'second crop'
- 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
What is green harvesting? -Correct Answer ✔Removal of second crop during summer
WSET
,WSET
Define one-year-old wood -Correct Answer ✔the main shoots from the last growing
season that were kept at pruning, supports compound buds; cane or spur
Define permanent wood -Correct Answer ✔woody parts of the vine that are older than
one year, including the trunk
where are most roots found? -Correct Answer ✔top 50cm of soil
what distinguishes PN clone 115? -Correct Answer ✔low yield, small grapes, good for
high quality of red wines
what distinguishes PN clone 521? -Correct Answer ✔high yield, bigger grapes, good for
sparkling wine production
When is leaf fall and dormancy? -Correct Answer ✔Nov-March
When is budburst? -Correct Answer ✔March-April
When is shoot and leaf growth? -Correct Answer ✔March-July
When is flowering and fruit set? -Correct Answer ✔May-June
When is grape development? -Correct Answer ✔June-Oct
When is harvest? -Correct Answer ✔Sept-Oct
How does the vine support itself during dormancy? -Correct Answer ✔starch in the
roots, trunk, and branches
Below what temp can vines be severly damaged? die? -Correct Answer ✔-15C, -25C
What factors determine the timing of budburst? -Correct Answer ✔- 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? -Correct Answer ✔marked differences in
temp can result in uniform budburst
what determines the vigor of a vine? -Correct Answer ✔rate of shoot growth
when does the fastest rate of shoot growth typically occur? -Correct Answer ✔between
budburst and flowering
WSET
, WSET
what could cause low carb levels in roots, trunk, and branches? -Correct Answer ✔-
excessive leaf removal
- water stress
- high crop loads in prev season
what can slow initial shoot growth rates? -Correct Answer ✔low carb levels
what supports shoot growth in later stages? -Correct Answer ✔photosynthesis
at what point of the vine growing cycle is water stress not desired? -Correct Answer
✔late stages of shoot growth (can affect photosynthesis)
what can stunted shoot growth lead to? -Correct Answer ✔- weak shoots
- reduction in leaf number/smaller leaves
- inflorescences that do not flower properly
what can limit bud fruitfulness? -Correct Answer ✔- low temp (<25C)
- water stress
- shading
- nutrient deficiency
how long after budburst does flowering typically take place? -Correct Answer ✔8 weeks
(temp dependent)
why are warm conditions (>17C) desired during flowering? -Correct Answer ✔speeds
up flowering (occurs within a few days)
what % of flowers become grapes typically? -Correct Answer ✔30%
what temp does pollen germination require? -Correct Answer ✔26-32C
what negatively affects pollen tube growth? -Correct Answer ✔wind, rain, cold temps;
wind, water stress, hot temps
define coulure -Correct Answer ✔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? -Correct Answer ✔imbalance in carb levels due to:
- low photosynthesis rates
- vigorous shoot growth diverting carbs (very fertile soils, vigorous rootstocks)
define millerandange -Correct Answer ✔A condition of the grape bunch in which there is
a high proportion of seedless grapes.
WSET
