COMPREHENSIVE QUESTIONS AND
ANSWERS VERIFIED ANSWERS EXAM PREP
QUESTIONS AND SOLUTIONS GRADED A+
⩥ What temps can cause a vine to freeze? Answer: -20C/-4F
⩥ What temperature stimulates budburst? Answer: Above 10C/50F
⩥ What is the optimum temp range for photosynthesis? Answer: 18-33C
(64-91F)
⩥ What temp stimulates flowering? Answer: Above 17C/63F
⩥ What temp range causes fruit set? Answer: 26-33C/ 79-90F
⩥ What temp is best to promote bud fruitfullness Answer: Above
25C/77F
⩥ How does temp affect photosynthesis (4)? Answer: - sugars
accumulate in grapes faster in warmer temps bc of increased grape
transpiration
,- malic acid degradation increases with temp
- high temps lead to faster loss of acids
- cool temps slow breakdown of methoxypyrazines
- extreme hot & dry causes slows photosynthesis
⩥ At what point does lack of sunlight negatively affect photosynthesis?
Answer: If sunshine levels fall below 1/3rd of full sunshine
⩥ What effects does sunlight on grapes cause in black grapes? (2)
Answer: Development of anthocyanins (color pigments) and reduction
onf methoxypyrazines
⩥ Who does sunlight on grapes affect tannins? Answer: - sunshine leads
to a greater accumulation of tannins pre-verasion
- sunshine promotes tannin polymerisation after verasion
⩥ What is the main source of both heat and sunlight for a vine? Answer:
Solar radiation
⩥ Why is sunshine in later Spring/ early Summer so important? (2)
Answer: - helps fruit set
- sunlight on compound buds helps with bud fruitfullness in next year's
growing season
, ⩥ What are areas in lower latitudes (closer to the equator) generally
warmer? (2) Answer: - More powerful solar radiation (less distance to
travel through the atmosphere)
- more powerful when it hits at a direct angle
⩥ All things equal, what characteristics do grapes grown at lower
latitudes tend to have? (5) Answer: Higher sugar levels
Lower acid
Ripe aromas
Higher but riper tannins
More color intensity
⩥ What is (generally) the latitude boundary for wine grape growth?
Answer: Wine grapes generally grown bw 30-50 degrees latitude
⩥ How are temps affected by altitude? Answer: Temps falls about .6C/
1.1F for every 100m increase in altitude
⩥ How does the increased solar and ultraviolet radiation at high altitude
sights help with ripening ? (2) Answer: - promotes anthocyanin synthesis
- promotes tannin synthesis
⩥ Why do high altitude sights have greater diurnal range vs lower
altitudes? Answer: At higher altitude, the ground absorbs the solar