Growing Environment Flashcards
What is the huglin index
Similar climate classification system to add except that it takes into account the highest temp as well as average, and increased day length at different latitudes. It can be used to estimate the suitability of certain regions for various varieties. Grape varieties are mapped into the most suitable range.
Where is the huglin index used mostly?
Europe
What is the MJT
Mean January/ July temperature (for north and south hemisphere)
Average temp at the height of summer. Measured temp, humidity, continentality, hours of sunshine
GST?
Growing season temperature
Like gdd but easier to calculate
How might you delay flowering, and why?
Which grape might need this?
Later winter pruning can delay fruit set.
This is important as it means flowering can be delayed by up to 2 weeks, pushing it into warmer, drier weather. For early ripening varieties (such as Chardonnay) this can mean flowering happens in better weather, later on, avoiding bad weather earlier in the year.
There is a risk of uneven fruit set if flowering happens during rainy weather
What temperature range describes a moderate climate
An average GST of 16.5-18.5C
What temperature range describes a cool climate
An average GST of 16.5C or below
What temperature range describes a warm climate
An average GST of 18.5-21
What temperature range describes a Hot climate?
An average GST of 21+
What are the primary roles of soil? (3)
- support the root structure
- medium for taking in water and nutrients
- home to micro eco system
What is the difference between the texture and the structure of soil
Texture: proportions of sand, clay and silt. High proportion of clay = finely textured.
High proportion of sand = loosely textured
Structure:
Describes how the mineral particles in the soil form aggregates. The size, shape and stability of these aggregates is important in understanding how the plant will respond to its surroundings
What is loam?
A mix of sand, clay and silt
Name 3 key chemicals and their role in plant growth and health
1) nitrogen- crucial for photosynthesis. Too much = too much vegetal growth. Too little, the plant yellows. Also important to have enough N in the grape for fermentation
2) potassium: important for regulating flow of water in the vine. Too much: and not enough magnesium. Too little and low sugar and lower yields.
3) phosphorus: key for photosynthesis. Also important for root structure. Not much is needed and there’s usually enough in the soil.
Calcium - cell structure and photosynthesis
Magnesium- photosynthesis
Would you find more or less iron in soils with a high pH?
Low. Iron tends not to be found in alkaline soils. Low iron levels can cause chlorosis.
What mineral will not be found easily in a low pH soil?
Phosphorus. Good for photosynthesis and root structure.
Give an example of why you might need irrigation in an area with 100ml or rain a year (and name that Région)
Gimblett Gravels in Hawkes Bay, NZ.
Despite plentiful rain, the extremely low water retention of the soil means that water does not stay around.
Describe transpiration
As water is lost through the stomata, the vine pulls water up from the soil, through the roots and into the plant.
What causes stomata to close, and what problems does this cause?
Water stress- if there isn’t enough water in the soil, the stomata close to keep the water that is already in the plant.
Closed stomata mean there isn’t any CO2 coming into the plant which means photosynthesis can’t happen, or happens at a reduced rate.
What does photosynthesis do?
It allows the plant to convert sunlight and minerals into sugar for energy
