Ch. 3: The Growing Environment Flashcards
Maritime
A climate classification used in grape growing to understand a growing region and its effect on wine style and quality. A Maritime climate is one that does not have a high variation in temperature between Winter and Summer, has relatively high amounts of rainfall, and can have rainfall throughout the year. Because of the moist environment and plentiful rainfall, good soil drainage and disease management are important considerations for wine quality. e.g.) Bordeaux
Mediterranean
A climate classification in which the annual differences in temperatures between winter and summer are low, rainfall occurs mostly in the winter and can be relatively low, and summers are warm and dry. Because of lack of rainfall, Mediterranean climates can be prone to drought, and irrigation is often required to grow healthy, high yielding vines. Additionally, grapes can ripen quickly, accumulating sugar and dropping acid before tannins and flavors are fully developed. This often requires adjustments in the winemaking process to balance acidity. e.g.) Napa
Continental
A climate classification in which the annual differences between winter and summer are high. Continental climates often have very cold winters, cool autumns, and warm Summers.
Solar radiation
The main source of heat and sunlight for the vine, both of which are critical for vine growth, grape formation, and grape ripening.
Generally speaking, Regions at lower latitudes (Mendoza, South Africa) will receive more solar radiation than those at higher latitudes (Northern France, Germany). This means that temperatures are generally warmer and sunshine more intense. Broadly, grapes have higher sugar, lower acidity, riper aromas, and higher, riper tannins, and more color intensity, all other factors being equal.
At higher latitudes, solar radiation is more diffuse since it hits the earth at a lower angle and needs to travel through more atmosphere. However, hours of sunlight are longer in the summer leading to longer hours of ripening during the growing season. Planting on slopes towards the equator can increase solar radiation and mitigate for the cooler temperatures.
Latitude
A natural factor that effects temperature and sunlight. Regions at lower latitudes (Mendoza, South Africa) will generally receive more solar radiation than those regions at higher altitudes (France, Germany). Regions nearer the equator also receive more intense solar radiation. Generally, this means that grapes grown at lower latitudes will have more sugar, less acid, riper aromas, higher but riper tannins (in red grapes) , and more color intensity than those at higher latitudes.
At lower altitudes, the number of hours of daylight is consistent year around, whereas at higher altitudes, the amount of daylight in the Summer is longer than in the winter. This can benefit cooler regions at high altitudes by providing a longer amount of time for Photosynthesis during the growing season.
Altitude
Temperature falls by approx. 1.1F for every 100 m increase in altitude. High altitude regions can therefore be beneficial to areas of low latitude, that would otherwise be too hot to grow grapes. Sunshine is more intense in high altitude regions, promoting anthocyanin and tannin synthesis.
High altitude areas also have a high diurnal range, which in warm climates, can be beneficial in maintaining acid during ripening.
Diurnal range
The average temperature difference between daytime and nighttime temperatures.
Regions with Continental climates or at high altitude tend to have higher diurnal ranges, while regions near a large body of water tend to have lower diurnal ranges.
The effects of diurnal range on the grapes will depend on the avg. day and nighttime temperatures, grape varietal, water availablilty, and time in the growth cycle.
For example, in warm climates such as Mendoza or Ribera del Duero, a large diurnal range is thought to be beneficial as cooler nighttime temperatures preserve acidity in the grapes.
Aspect
Aspect is the direction the vineyard faces towards the sun. Vineyards facing the equator tend to get more intense sun and benefit from a longer growing season. East facing vineyards get the gentler, morning sunlight, which warms the vineyard up more quickly and can lead to longer ripening times during the day. West facing vineyards get more intense, afternoon sunlight, which can become too hot and risk sunburnt grapes.
The importance of aspect (and slope steepness) increases at high latitudes because of the cooler avg temperatures. Extra warmth and light extend the viable growing seasong for vines grown on slopes that face the equator. Burgundy and Alsace are examples, where the Grand Cru vineyards face on southeast facing slopes.
In warm climates, it may be desirable to limit the amount of heat and light, and planting on slopes that face away from the equator can help.
Stomata
The pores on the underside of vine leaves allow the exchange of water vapor out of the vine, and C02 (and oxygen) in and out of the leaves, encouraging photosynthesis. The loss of water from the stomata causes water to be pulled up into the vine from the soil. If there is not enough water for the vine, the stomata will close, preserving water but also, not letting C02 enter the vine, thereby slowing or stopping photosynthesis.
Evapotranspiration rate
The amount of transpriation from the vine, combined with the amount of evaporation from the soil. It depends on temperature, humidity, and wind, with hot, dry, windy environments leading to the fastest rates.
A high rate means that more water is needed for the health of the vine. Irrigation may be required in hot, dry, windy conditions (Mendoza, Patagonia).
Nitrogen
Essential for vine growth and has a major impact on vine vigor and grape quality.
Too much nitrogen causes excessive vegetative growth, which can divert nutrients and sugars from grapes and shade grapes, reducing ventilation and sunlight and increasing disease pressure.
Too little nitrogen leads to reduced vigor and yellowing of the leaves. Grapes with low nitrogen can also cause problems with fermentation because the yeasts need nitrogen to successfully convert sugars into alcohol.
Potassium
Helps regulate the flow of water in the vine. High levels of potassium in the soil can lead to high potassium and pH levels in the grapes, which lowers quality and increases chances of spoilage.
Levels that are too low can lead to reduced grape yields and poor vine growth.
Phosphorous
Important for photosynthesis. There is usually enough in the soil for vines.
A deficiency leads to poorly developed root systems, reduced grape yields and poor vine growth.
Calcium
Important for photosynthesis and plant cell structure.
Deficiency is rare but can negatively affect fruit set.
Magnesium
Has a key role in photosynthesis.
Deficiency can result in reduced yields and poor ripening.
