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