Quiz - Vineyard Management Flashcards
Briefly describe the main nutrient and weed management techniques in the vineyard.
Organic fertilisers
Made from fresh or composted plant or animal material, such as manure or slurry. Spread onto vineyards by hand.
Inorganic fertilisers
Manufactured from minerals extracted from the ground or synthetic chemicals, they can provide a single nutrient and are more targeted
Cultivation
Involves ploughing the soil to cut or disturb the weeds’ root systems.
Herbicides
Chemical sprays that kill weeds.
Animal grazing
Animals are allowed to eat the weeds in the vineyard.
Cover crops
Introducing plants that are specifically planted, or allowed to grow, that have a beneficial effect on the vineyard.
Mulching
Spreading matter (usually biodegradable materials) onto the vineyard soil to suppress the growth of weeds.
What does RDI stand for in relation to vineyard irrigation?
Regulated deficit irrigation
Why do the soils in the Médoc enable the production of high-quality wines?
The climate is described as moderate maritime, moderate summers and winters with rainfall evenly spread through the year.
Free draining stony soils warm up more quickly in spring which influences the date of budburst. An earlier budburst can be beneficial in this moderate climate as it could potentially increase the length of the growing season, important for ripening Cabernet Sauvignon. Stony soils will also absorb heat which is then released back to the vines.
Irrigation is not necessary or permitted. The soils are gravel composition which allows for easy and quick drainage in this high rainfall area; water-logging is generally not an issue.
Briefly explain the main aims of vine canopy management and the effects they have on the vineyard and resultant grapes.
The key aims of canopy management are to:
* Maximize the effect of light interception by the vine canopy
* Reduce the shade within the canopy
* Ensure that the microclimate for the grapes is as uniform as possible so that grapes ripen evenly
* Promote balance between the vegetative and reproductive functions of the vine
* Arrange the vine canopy to ease mechanization and / or manual labor
* Promote air circulation through the canopy to reduce incidence of disease
The effects of promoting sunlight exposure within the canopy include:
* increased sugar levels in grapes through greater overall photosynthesis in the vine
* increased tannin levels and greater polymerization of those tannins, leading to less bitterness
* enhanced anthocyanin (color) development in black grapes
* decreased malic acid – warmer grape temperatures lead to more malic acid being broken down in cellular respiration, otherwise, especially in cool climates, acidity levels in the wine could be unpleasantly high (tartaric acid remains)
* increased levels of some favorable aroma precursors and aroma compounds such as terpenes, which are responsible for many of the fruity and floral aromas in wines such as the grapey aromas found in Muscat
* decreased methoxypyrazines, which give herbaceous characters in grape varieties such as Cabernet Sauvignon.
* Decreased disease risk (e.g. fungal diseases) due to improved air circulation.
Define over-cropping and under-cropping
When the yield of the fruit is too high compared to the vigor of the vine, this is termed over-cropping
When the yield of the fruit is too low compared to the vigor of the vine, this is termed under-cropping
In which ways are yields generally measured?
Kilogram per hectare
Kilogram per vine
Tons per hectare
What are the most popular training/trellising systems used?
- Bush vine
- VSP replacement cane
- VSP cordon trained
- Geneva Double Curtain
- Lyre
- Scott-Henry
Describe the water needs of a vine.
What happens, if the vine doesn’t get enough water?
Unless planted at very low vine densities, in cool climates, a minimum of 500 mm of water per year is required for a vine to successfully grow. In warm regions, it is at least 750 ml.
If the vine does not get enough water, the stomata on the leaves close to try and limit water loss; this will have a negative impact on the rate of photosynthesis. If the vine does not receive water and the situation continues, it will die.
What can happen if the vine gets too much water?
If vines are exposed to too much water, excessive vegetative growth can occur; this can stop grapes from ripening as the fruit will be too shaded.
High levels of rainfall can also make the canopy prone to fungal diseases because of high
humidity. If there are not good drainage systems in place or if the soils are not free draining,
waterlogging may occur; this can reduce the amount of oxygen available to the roots, which will ultimately kill the vine.
If a region is particularly susceptible to high levels of rainfall, it’s important that the vineyard is designed in a way that lessens the effect of excess water. Planting vineyards on slopes or on free-draining soil can help improve drainage.
What are the vineyard management options that may be employed to combat winter freeze?
- Burying the vines.
- Select frost/cold resistant species and rootstocks.
- Plant vines on hillsides.
- Plant vines in areas where snow settles.
- Plant vines near large/deep bodies of water
If a vineyard was located in a hot region of the Northern Hemisphere, which of the following vine row orientations would you avoid to try to counteract sunburn?
East to west
This orientation should be avoided so that grapes on the south side of the row are not subject to day-long sun and to intense afternoon sunshine.
Describe the major vineyard pests.
Phylloxera
This aphid-like insect feeds on and lays eggs on the roots of grape vines. It harms the vine by damaging its roots.
Nematodes
Microscopic worms which feed off vine roots, significantly reducing yields and vigour. They can cause slow, gradual decline or transmit viral diseases.
Grape Moths
Feed on flowers and grapes. Often have several generations per season, which attack flowers in spring and grapes further on in the season. The wounds created are then susceptible to bacteria and fungi.
Spider Mites
Feed on the surface cells of leaves. This leads to discoloration of the leaves, a reduction in photosynthesis, delayed ripening and a reduction in yields.
Name the major types of hazards.
Pests :
* Grape Moths
* Spider Mites
* Nematodes
* Phylloxera
Viruses:
* Leafroll
* Fanleaf
Bacterial Diseases:
* Grapevine Yellows
* Pierce’s Disease
Fungal Diseases:
* Grey Rot
* Downy Mildew
* Powdery Mildew
* Esca
* Phomopsis
* Eutypa Dieback
Briefly outline common management techniques employed in the vineyard to counteract phylloxera. Explain how these techniques help alleviate and eradicate the symptoms of phylloxera.
Management options to counteract phylloxera:
* Graft the European vitis vinifera varieties on American rootstocks , especially, Vitis berlandieri, Vitis riparia and Vitis rupestris.
* However, problems arise when grafting on American rootstocks on calcareous soils, vines may suffer from chlorosis. Solution was the creation of hybrids between American species
* Planting on rootstocks is significantly more expensive than on the vines’ own roots, but has become a standard part of the cost of establishing a vineyard.
* Planting on sandy soils can also be an alternative, if the choice is there, the pest cannot survive in this soil type.
Explain in detail how a wine producer may choose to define the ripeness of their grapes, and therefore when the grapes should be harvested. Take into account the following:
- The different ways ripeness can be defined.
- How climate and weather effect ripeness.
- How the date of harvest can have an impact on the subsequent style of wine.
Ripeness can be defined by the producer as the grapes being ripe for the desired style of wine. The ripeness of the grapes will be measured by a set of parameters including grape sugars, aroma profile, tannin ripeness and acidity.
Climate and weather impact on the ripeness of the fruit and as a general guide, in warmer wine growing regions the sugars tend to be high and the acidity lower which contrasts with cooler climates where sugars can be low and acidity high. Aroma and tannin are impacted by temperature and depending on how warm or cool it is, this will influence the levels of aroma precursors, like methoxypyrazines. Sunshine on black grapes promotes tannin accumulation and polymerization which impacts on the astringency of the tannins.
The date of harvest has a significant influence on the wine style, but it also gives options to the producer i.e picking on sugar levels can mean harvesting earlier in warmer sites or leaving the grapes longer on the vine in cooler sites to achieve the desired levels. This can be said for the other parameters also. The producer needs to understand how the climatic factors of temperature, sunlight and available water influence the grapes, then the decision to harvest can be made in light of the desired wine style.
