Define Flashcards
What the meaning of the word is
Define the word lignify and identify the time when lignification happens in the growth cycle.
In late summer, the leaves
fall from the vine and the green
shoots lignify (become woody,
rigid and brown); from this point
they are called canes.
Define the term evapotranspiration.
total loss of water from a vineyard
Define diurnal range.
The diurnal range of a region or vineyard site is the average difference between day-time
and night-time temperatures.
Define waterlogging.
If soils are not free draining, waterlogging may occur, reducing the amount of oxygen available to the roots, slowing down growth, and eventually killing the vine. Equally, waterlogging can lead to compaction of the soils, making them difficult to work, and uncontrolled water run-off.
Define monoculture.
In a vineyard, monoculture refers to the agricultural practice of growing only one type of grape variety over a large area. This means that the entire vineyard is planted with a single species or cultivar of grapevine, rather than a mix of different types.
Define economic threshold in regards to Lutte Raisonnée.
The grape grower regularly monitors the scale of potential problems and only intervenes before they reach an economic threshold (i.e. when the level of damage will exceed the cost of intervention). Integrated pest management (IPM, also known as lutte raisonée) is a key part of sustainable agriculture. It builds on some of the insights of organic viticulture, but it is prepared to use chemical interventions when necessary. It includes setting thresholds at which action needs to be taken (e.g. if pest populations reach a certain level), identifying and monitoring pests, setting up preventative measures, and evaluating and implementing control options (if threshold levels are exceeded and preventative measures have not been effective).
Define advective and radioactive frosts.
- Advective frosts are caused by large volumes of cold air moving in from very cold areas.
- Radiative frosts are the result of heat being lost on still, cool nights. The earth is heated by the sun during the day and releases it during the night. The amount of heat lost depends on the level of cloud cover. Windless nights will allow a layer of freezing cold air to develop just above the surface of the soil. As cold air is denser than warm air, this freezing cold air will collect in valley bottoms.
Define peronospora.
A water mould that lives within vine tissue, not on the surface; the cause of Downy Mildew.
Define and give an example of a vector.
A vector is an organism that transmits a disease. (e.g. The bacterium of Pierce’s Disease is spread by the sharpshooter insect)
Define total acidity.
the sum of all the acids in the wine. (g/L)
Define malolactic conversion.
Widely known as malolactic fermentation (“MALO”), is the conversion of stronger malic acid naturally present in new wine into lactic acid (which has lower acidity) and carbon dioxide.
Define sterilization.
the elimination of unwanted organisms; for example, from high risk areas such as the filler heads of bottling lines – these can be sterilised with high strength
alcohol or with steam.
Define sparging.
Oxygen dissolved in wine can accelerate the speed of ageing of the wine and thus reduce its shelf life. If the levels of oxygen are found to be too high, it can be removed by flushing the wine with an inert gas to remove it, a process called sparging.
Define appassimento.
In this method, grapes are picked and then dried. This can last from days to months depending on the extent of drying required and the speed of the drying process. Bunches of grapes may be laid out to dry in the sun in warm climates, such as southern Italy or Spain, or dried in a temperature- and humidity-controlled room in cooler climates, which gives the ability to speed up drying and avoid the development of grey rot, for example in Valpolicella. (A humidity-controlled room is clearly more expensive to build and maintain than drying grapes outside.) This drying process causes water to evaporate, making the sugars, acids and flavours become more concentrated. This method is often referred to by the Italian term, appassimento. Wines made in this way include Recioto di Valpolicella and Vin Santo.
