WSET DIPLOMA D1 - SECTION 3 QUESTIONS AND
ANSWERS
What is the main source of both heat and sunlight? - Answers :Solar radiation
What temperature ensures the dormancy of vines - Answers :Under 10C / 50F
What temperature can cause winter freeze and damage vines? - Answers :-20C / -4F
What factors can stimulate budburst? - Answers :Temperatures above 10C / 50F
Warm soil temperatures
What is the optimal temperature for shoot growth and leaf development? - Answers :18-
33C / 64-91F
What temperatures promote successful flowering? - Answers :Above 17C / 63F
What temperatures promote successful fruit set - Answers :26-32C / 79-90F
What is the impact of cold, damp conditions? - Answers :Problems for flowering and fruit
set reducing yield and quality
How does temperature impact grape ripening - Answers :Sugar accumulation is faster
at warmer temperatures
Malic acid degradation increases at warm temperature
Formation of aroma precursors and compounds
Color
Tannins
How does current year temperatures impact the following year - Answers :Warm
temperatures promote bud fruitfulness next year
How does temperature accelerate sugar accumulation? - Answers :Optimal rates of
photosynthesis
Increased grape transpiration moving sugar to grapes
What temperatures impact malic acid degradation - Answers :Mean temps > 21C / 70F
can lead to rapid acid loss
Mean temps <15C / 59F can reduce acid loss
What impact does temperature have on aroma precursors and compounds? - Answers
:Warmer climates = riper aromas/flavors
Cooler climates = hinder breakdown of Methoxypyrazines
What is the optimal temperature for anthocyanin synthesis - Answers :15-25C / 59-77F
, Extreme heat and dry condition can negatively impact what vine process? - Answers
:Photosynthesis can slow or stop, slowing vine growth and grape ripening
Why does heat impact photosynthesis - Answers :Heat sensitivity of enzymes that
catalyse photosynthesis
Why does water stress impact photosynthesis? - Answers :Shutting of stomata prevent
water loss. Closed stomata limit intake of CO2
At what level of sunlight is photosynthesis negatively impacted? - Answers :Below 1/3 of
full sunshine
What positive impact does sunshine have on grapes (8)? - Answers :Development of
anthocyanins in black grapes
Reduction of methoxypyrazines
Accumulation of tannins pre-verasion
Tannin polymerisation after versasion
Increased levels of aroma precursors and compounds
Warms grapes which increases rate of malic acid drop
Successful fruit set
Bud fruitfulness for next year's growth
What negative impact does sunshine have on grapes? - Answers :Prolonged sunshine
+ hot temps = sunburn
How do grape growers protect against sunburn? - Answers :Ensure grapes are covered
with 1 thin layer of leaves
What are components of the growing environment (8)? - Answers :Factors affecting
temp and sunlight
Factors affecting water availability
Factors affecting nutrient availability
Climate classification
Weather influences
Climate change
Hazards
Pests and diseases
What are the factors that affect temperature and sunlight (8)? - Answers :Latitude
(closer to equator = more)
Altitude
Slopes and aspect
Proximity to water
Winds
Characteristics of the soil
ANSWERS
What is the main source of both heat and sunlight? - Answers :Solar radiation
What temperature ensures the dormancy of vines - Answers :Under 10C / 50F
What temperature can cause winter freeze and damage vines? - Answers :-20C / -4F
What factors can stimulate budburst? - Answers :Temperatures above 10C / 50F
Warm soil temperatures
What is the optimal temperature for shoot growth and leaf development? - Answers :18-
33C / 64-91F
What temperatures promote successful flowering? - Answers :Above 17C / 63F
What temperatures promote successful fruit set - Answers :26-32C / 79-90F
What is the impact of cold, damp conditions? - Answers :Problems for flowering and fruit
set reducing yield and quality
How does temperature impact grape ripening - Answers :Sugar accumulation is faster
at warmer temperatures
Malic acid degradation increases at warm temperature
Formation of aroma precursors and compounds
Color
Tannins
How does current year temperatures impact the following year - Answers :Warm
temperatures promote bud fruitfulness next year
How does temperature accelerate sugar accumulation? - Answers :Optimal rates of
photosynthesis
Increased grape transpiration moving sugar to grapes
What temperatures impact malic acid degradation - Answers :Mean temps > 21C / 70F
can lead to rapid acid loss
Mean temps <15C / 59F can reduce acid loss
What impact does temperature have on aroma precursors and compounds? - Answers
:Warmer climates = riper aromas/flavors
Cooler climates = hinder breakdown of Methoxypyrazines
What is the optimal temperature for anthocyanin synthesis - Answers :15-25C / 59-77F
, Extreme heat and dry condition can negatively impact what vine process? - Answers
:Photosynthesis can slow or stop, slowing vine growth and grape ripening
Why does heat impact photosynthesis - Answers :Heat sensitivity of enzymes that
catalyse photosynthesis
Why does water stress impact photosynthesis? - Answers :Shutting of stomata prevent
water loss. Closed stomata limit intake of CO2
At what level of sunlight is photosynthesis negatively impacted? - Answers :Below 1/3 of
full sunshine
What positive impact does sunshine have on grapes (8)? - Answers :Development of
anthocyanins in black grapes
Reduction of methoxypyrazines
Accumulation of tannins pre-verasion
Tannin polymerisation after versasion
Increased levels of aroma precursors and compounds
Warms grapes which increases rate of malic acid drop
Successful fruit set
Bud fruitfulness for next year's growth
What negative impact does sunshine have on grapes? - Answers :Prolonged sunshine
+ hot temps = sunburn
How do grape growers protect against sunburn? - Answers :Ensure grapes are covered
with 1 thin layer of leaves
What are components of the growing environment (8)? - Answers :Factors affecting
temp and sunlight
Factors affecting water availability
Factors affecting nutrient availability
Climate classification
Weather influences
Climate change
Hazards
Pests and diseases
What are the factors that affect temperature and sunlight (8)? - Answers :Latitude
(closer to equator = more)
Altitude
Slopes and aspect
Proximity to water
Winds
Characteristics of the soil
