WSET Diploma D1 Exercises (The Growing Environment: part 1)

Answer

Sunshine enhances anthocyanin development in black grapes, reduces methoxypyrazines that serve as precursors to immature aromas, and increases levels of some aroma precursors and compounds, such as terpenes. It also boosts tannin accumulation before véraison and promotes tannin polymerization after véraison. Additionally, sunshine warms the grapes, accelerating the metabolism of malic acid and thus reducing acidity levels to a desirable amount. Overall, these effects have a positive impact on flaver and taste.

Prolonged exposure to intense sunshine can lead to sunburn, adversely affecting grape quality and yields. To mitigate this, grape growers protect the vines by shading them with a thin layer of leaves, ensuring the grapes receive filtered sunlight.

Grading Criteria

• Positive effect
  • For each listed change directly driven by sunshine, you get 1 point, totaling 5 points:
    • Enhances anthocyanin development in black grapes
    • Reduces methoxypyrazines
    • Increases levels of some aroma precursors and compounds
    • Boosts tannin accumulation before véraison
    • Promotes tannin polymerization after véraison
  • For the positive effect of reducing methoxypyrazines, such as diminishing immature aromas, you get 1 point.
  • For examples of increased positive aroma compounds or aroma precursors such as terpenes, you get 1 point.
  • For pointing out that sunshine warms the grapes, you get 1 point.
  • For highlighting that this accelerates the metabolism of malic acid, you get 1 point.
  • For the conclusion that this process reduces acidity levels to a desirable amount, you get 1 point.
• Negative effect
  • For the statement that prolonged exposure to intense sunshine can cause sunburn, you get 1 point.
  • For the conclusion that sunburn negatively impacts grape quality and yields, you get 1 point.
• Measurement
  • For the statement that grape producers use shading to protect vines from sunburn, you get 1 point.
  • For the statement that they use a thin layer of leaves for shading, you get 1 point.

Answer

Given that solar radiation strikes at a lower angle in low-latitude regions, temperatures are typically higher and sunshine is more strong at lower latitude than in areas at the higher latitudes. As a result, in equatorial areas where daytime temperatures are consistently high, vines promote more transpiration than they can supply, leading to severe water stress. This is a primary challenge in cultivating grapes in low-latitude regions. Additionally, the intense sunlight can cause sunburn on the grapes, further complicating vineyard management and grape quality.

Grading Criteria

• For the premise that solar radiation strikes at a lower angle in low-latitude regions, you get 1 point.
• For the below two national conditions that negatively affect grape growing, you get 1 point each, totaling 2 points:
  • High temperature
  • Strong sunshine
• For the statement that vines undergo more transpiration than they can sustain, you get 1 point.
• For the conclusion that this leads to severe water stress, which complicates growing grapes at low latitudes, you get 1 point.
• For the statement that intense sunlight can cause sunburn on the grapes, which also complicates grape cultivation at low latitudes, you get 1 point.

Answer

Sunshine, and consequently ultraviolet radiation, is more intense at high altitudes than at low altitudes because solar radiation travels through less atmosphere before reaching these sites. This enhances tannin synthesis, leading to higher tannin levels in grapes grown at high altitudes compared to those at lower altitudes.

High-altitude sites often have a high diurnal range because the thin atmosphere at these elevations contains less moisture, which absorbs and retains less energy. Consequently, it cools quickly at night due to radiative cooling. In warmer climates, this pronounced diurnal range is beneficial for maintaining acidity in grapes during ripening. Cooler nighttime temperatures slow down grape respiration, which in turn reduces the metabolism of malic acid.

Grading Criteria

• Tannin
  • For pointing out that sunshine and ultraviolet radiation are more intense at high altitudes than at low altitudes, you get 1 point.
  • For explaining that this is because solar radiation travels through less atmosphere before reaching these sites, you get 1 point.
  • For stating that strong sunshine and ultraviolet radiation enhance tannin synthesis, you get 1 point.
  • For concluding that the level of tannin in grapes grown at high altitudes is higher than in those grown at lower altitudes, you get 1 point.
• Acid
  • For the statement that high-altitude sites often have a high diurnal range, you get 1 point.
  • For explaining that this occurs because the thin atmosphere at higher elevations cools quickly at night, you get 1 point.
  • For the explanation that this is because atmosphere of high-altitude have less moisture which absorbs and retains energy, you get 1 point.
  • For the explanation that a high diurnal range or cool nighttime temperatures reduce grape respiration, you get 1 point.
  • For stating that this in turn slows down the metabolism of malic acid, you get 1 point.
  • For the conclusion that grapes grown at high-altitude sites retain higher acidity compared to those at low altitudes, you get 1 point.

Answer

In cool climates, achieving sufficient heat and light during the growing season is crucial for proper ripening. South-facing slopes increase the angle at which solar radiation hits, providing grapes with more intense heat and light, which are essential for adequate ripening.

Moreover, vines planted on south-facing slopes receive additional heat and light in spring and autumn. This extended exposure ensures that grapes benefit from prolonged heat and light, which supports the ripening process.

Grading Criteria

• For the premise that achieving sufficient heat and light during the growing season is crucial for proper ripening in cool climates, you get 1 point.
• For the statement that south-facing slopes increase the angle at which solar radiation is incident, you get 1 point.
• For the explanation that this provides grapes with more intense heat and light, you get 1 point.
• For the statement that south-facing slopes receive additional warmth and light in spring and autumn, you get 1 point.
• For the explanation that this ensures prolonged heat and light for grapes, you get 1 point.

Answer

Lakes, being large bodies of water, heat up and cool down more slowly than dry land. During winter, deep lakes like the Finger Lakes retain the warmth gained during summer, keeping the surrounding area warmer. Consequently, close proximity to these deep lakes reduces the severity of winter freezes, which could otherwise damage or even kill the vines.

The temperatures of the air above land and lake differ, arising daily air convection. Consequently, this air movement prevents stagnation of cold air, which helps protect against spring frosts that could otherwise reduce yields.

Grading Criteria

• For the premise that large bodies of water heat up and cool down more slowly than dry land, you get 1 point.
• For pointing out that winter freezes in the Finger Lakes are severe enough to damage or even kill vines, you get 1 point.
• For the statement that deep lakes like the Finger Lakes retain warmth gained during the summer for an extended period, you get 1 point.
• For the statement that this warmth keeps the surrounding area warmer during winter, you get 1 point.
• For the conclusion that close proximity to deep lakes reduces the severity of winter freezes, you get 1 point.
• For pointing out that spring frosts in the Finger Lakes are severe enough to reduce yields, you get 1 point.
• For explaining that spring frosts typically cause stagnation of cold air, you get 1 point.
• For the statement that temperatures above land and lake differ, you get 1 point.
• For the statement that this temperature difference causes daily air convection or movement, you get 1 point.
• For the conclusion that this movement prevents the stagnation of cold air, you get 1 point.

Answer

Margaux in Bordeaux and the Willamette Valley are located at nearly the same latitude and are both influenced by the ocean. However, Margaux primarily cultivates Cabernet Sauvignon, a late-ripening variety, due to the warm currents of the Gulf Stream, which warm many European wine regions. In contrast, the Willamette Valley is known for its Pinot Noir, an early-ripening variety, made possible by the cooler California Current that affects the western USA’s wine regions.

Grading Criteria

• Margaux
  • For the statement that Margaux primarily cultivates a late-ripening variety, you get 1 point.
  • For citing examples of late-ripening varieties such as Cabernet Sauvignon, you get 1 point.
  • For stating that Margaux in Bordeaux is influenced by the Gulf Stream, you get 1 point. Points will be broadly awarded for mentioning that Bordeaux is influenced by the ocean.
  • For noting that the Gulf Stream is a warm current, you get 1 point.
  • For concluding that the Gulf Stream warms Bordeaux sufficiently to support the growth of late-ripening varieties, you get 1 point.
• The Willamette Valley
  • For the statement that the Willamette Valley cultivates an early-ripening variety, you get 1 point.
  • For citing examples of early-ripening varieties such as Pinot Noir, you get 1 point.
  • For stating that the Willamette Valley is influenced by the California Current, you get 1 point. Points will be broadly awarded for mentioning that the Willamette Valley is influenced by the ocean.
  • For noting that the California Current is a cool current, you get 1 point.
  • For concluding that the California Current cools the Willamette Valley sufficiently to support the growth of early-ripening varieties, you get 1 point.

Answer

Here’s your corrected and refined text, with the changes highlighted in bold:

In cool climates, where sugar accumulation and ripening can be challenging, maximizing sugar production during the growing season and heating up grapes in the ripening season are crucial. Light-colored soils reflect solar radiation, directing extra light energy to the lower parts of the canopy that receive less direct sunlight, thus enhancing photosynthesis and grape ripening.

Dark-colored soils address this issue by absorbing more energy during the day and re-radiating it at night, helping to maintain a warmer microclimate around the vines. This continuous warmth facilitates the development of color and the breakdown of acids overnight, which is essential for achieving well-ripened grapes.

Grading Criteria

• For the premise that sugar accumulation and ripening can be challenging in cool climates, you receive 1 point.
• For listing the two challenges of growing vines in cool climates, you receive 1 point for each, totaling 2 points:
  • Maximizing sugar production during the growing season.
  • Heating up grapes during the ripening season.
• Light-colored soils
  • For the statement that light-colored soils reflect solar radiation effectively, you receive 1 point.
  • For the statement that light-colored soils direct extra light energy to the lower parts of the canopy, you receive 1 point.
  • For the statement that the lower parts of the canopy generally receive less direct sunlight, you receive 1 point.
  • For the conclusion that this extra light energy enhances photosynthesis during growing season and grape ripening during ripenin season, you receive 1 point.
• Dark-colored soils
  • For the statement that dark-colored soils absorb more energy during the day and re-radiate it at night, you receive 1 point.
  • For the statement that this helps maintain a warmer microclimate around the vines, you receive 1 point.
  • For the conclusion that this continuous warmth facilitates the development of color and the breakdown of acids overnight during ripening season, you receive 1 point.