1|Page
WSET DIPLOMA D1 EXAM 2026-
ACTUAL QUESTIONS WITH ANSWERS
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
,2|Page
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
,3|Page
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.
what causes millerandange? - correct-answer -cold, wet, windy weather at
pollination and fruit set
what elements develop in grapes during stage 1 of grape formation and
development? - correct-answer -- tartaric and malic
- some aroma compounds and aroma precursors (methoxypyrazines)
- tannins (promoted by sunshine on grapes - sunscreen)
during stage 1 of grape formation and development sugar levels are ______,
water flow is _______ & provided by the ________. - correct-answer -- low
, 4|Page
- high
- xylem
too much _________ & __________ can prolong stage 1 of grape formation and
development because _____________. this can delay _____________. - correct-
answer -- water
- nitrogen
- these will encourage shoot growth instead
- onset of the ripening stage
During stage 1 of grape formation and development, mild water stress can
___________________ and lead to the production of _______________ grapes. -
correct-answer -- speed up this stage
- smaller
shoot growth _______________ during stage 1 of grape formation and
development. - correct-answer -continues but slows
what is stage 2 of grape formation and development? - correct-answer -veraison,
transition between grape growth and grape ripening
WSET DIPLOMA D1 EXAM 2026-
ACTUAL QUESTIONS WITH ANSWERS
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
,2|Page
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
,3|Page
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.
what causes millerandange? - correct-answer -cold, wet, windy weather at
pollination and fruit set
what elements develop in grapes during stage 1 of grape formation and
development? - correct-answer -- tartaric and malic
- some aroma compounds and aroma precursors (methoxypyrazines)
- tannins (promoted by sunshine on grapes - sunscreen)
during stage 1 of grape formation and development sugar levels are ______,
water flow is _______ & provided by the ________. - correct-answer -- low
, 4|Page
- high
- xylem
too much _________ & __________ can prolong stage 1 of grape formation and
development because _____________. this can delay _____________. - correct-
answer -- water
- nitrogen
- these will encourage shoot growth instead
- onset of the ripening stage
During stage 1 of grape formation and development, mild water stress can
___________________ and lead to the production of _______________ grapes. -
correct-answer -- speed up this stage
- smaller
shoot growth _______________ during stage 1 of grape formation and
development. - correct-answer -continues but slows
what is stage 2 of grape formation and development? - correct-answer -veraison,
transition between grape growth and grape ripening
