4. Approaches to Grape Growing

Question 1

What are the aims of conventional viticulture and how are they achieved?

Answer 1

The aims included raising production levels and reducing labour requirements. This was achieved by mechanisation, chemical inputs, irrigation and clonal selection.

Question 2

What are the advantages of conventional viticulture and monocultures?

Answer 2

• The ability to mechanise the work in the vineyard.
• The reduction of competition from other plants.
• The ability to tend to the specific needs of the grape variety planted (irrigation, nutrition level, treatments against hazards, pests and diseases) and hence to increase yields while minimising costs.

Question 3

What are the disadvantages of conventional viticulture and monocultures?

Answer 3

• Plants in a monoculture are much more prone to diseases and pests and therefore need more treatments or protection.
• Nutrients can be depleted as there is no natural ecosystem to replenish nutrients, requiring more applications of fertilisers.
• Residual chemicals from treatments can find their way into groundwater or the air, creating environmental damage.

Question 4

Why are vines in a monoculture more prone to disease?

Answer 4

This is because, for example, fungal diseases spread more quickly in a monoculture and because all the plants are affected simultaneously.

Question 5

What are the aims of sustaintable viticulture?

Answer 5

• To promote the natural ecosystems in the vineyard
• Maintain biodiversity
• Manage waste
• Minimise applications of chemicals and energy use
• Reduce the impact of viticulture on the wider environment.

Question 6

How are the aims of sustainable viticulture achieved?

Answer 6

Grape growers are encouraged to develop an in-depth understanding of the lifecycles of the vine and of vineyard pests and to monitor weather forecasts so that they can predict and prevent a pest or disease outbreak before it occurs.
Rather than simply following a regimented calendar of spraying, this enables them to time the applications so that they have the greatest impact. As a result, fewer applications are needed.

Question 7

What is Integrated Pest Management (IPM)?

Answer 7

Also known as Luttle Raisonée

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
* Evaluating and implementing control options (if threshold levels are exceeded and preventative measures have not been effective).

Question 8

Give three examples of organisations setting guidelines and standards for sustainable viticulture?

Answer 8

• LODI RULES (for Lodi, California)
• Sustainable Winegrowing NZ
• Sustainable Winegrowing South Africa.

Question 9

What are the advantages of sustainable viticulture?

Answer 9

• A more thoughtful approach to grape growing, with attention to the economic, social and environmental impact of viticulture.
• The deployment of a scientific understanding of the threats to successful grape growing (pests and diseases) to minimise the number of interventions needed.
• A reduction in the spraying of synthetic and traditional treatments.
• The consequent cost saving that has incentivised grape growers to work in a more
  sustainable way.

Question 10

What are the disadvantages of sustainable viticulture?

Answer 10

• The term is not protected and therefore can be used to promote wine without a clear set of standards.
• The danger that nationwide standards for sustainability can be set too low. New Zealand’s high rate of uptake for its scheme – virtually all commercial grape growers – has both been praised for reducing the amount of pesticides used but criticised for setting too low a bar for sustainable certification.

Question 11

What are the main aims of organic viticulture?

Answer 11

Organic viticulture seeks to improve the soil of the vineyard and the range of microbes and animals, such as earthworms, within it and thereby increase the health and disease-resistance of the vine. It rejects the use of manufactured (also known as synthetic) fertilisers, fungicides, herbicides and pesticides.

Question 12

What are the four key features of organic viticulture?

Answer 12

• The application of compost that breaks down in the soil. This provides a slow release of nutrients for vines, improves the structure of the soil and increases the biomass in the soil (the total quantity or weight of organisms in a given area or volume).
• The use of natural fertilisers (animal dung, natural calcium carbonate, etc.). The idea is to restore the natural balance of the vineyard.
• The cultivation of cover crops to prevent erosion of the soil and to contribute to the improvement of the life of the soil. This can be through ploughing them in (‘green manure’) or by improving biodiversity.
• The reduction of monoculture of vineyards by growing cover crops, planting hedges and establishing ‘islands’ of biodiversity.

Question 13

How do organic grape growers combat against mildew?

Answer 13

Traditional remedies such as sulfur and copper sulfate to combat mildews, and monitor the weather closely to determine when spraying against mildew is really necessary.

Question 14

What are the risks of using copper sulfate sprays against mildew?

Answer 14

Copper build up in the soil

Question 15

What is a method organic grape growers may use to combat against botrytis?

Answer 15

The bacterium Bacillus subtilis can be introduced, which competes with Botrytis cinerea for space on the grape.

Question 16

What is a method organic grape growers may use to combat against insects?

Answer 16

‘Sexual confusion’ techniques are commonly used. They involve the use of pheromone tags or capsules to disrupt the mating patterns of insects such as moths and mealy bugs, and in this way, limit their populations.

Question 17

What international organisation sets for standards for organic certification bodies globally?

Answer 17

All certification bodies should meet the standards set by IFOAM (International Federation of Organic Agriculture Movements).

Question 18

What is a universal requirement for vineyards acquiring organic certification?

Answer 18

A universal requirement is that the vineyard must undergo a period of conversion working to organic standards before it can be certified.

Question 19

What are the advantages of organic viticulture?

Answer 19

• The improvement of the health and disease-resistance of the vine
• The improvement of the health of the soil
• The elimination of spraying synthetic chemicals
• A saving on the cost of synthetic chemicals.

Question 20

What are the disadvantages of organic viticulture?

Answer 20

• A possible small reduction in yield generally
• Possibility of significant reductions in yield in difficult years (e.g. long periods of rainfall or high humidity)
• Increased reliance on copper sprays, which may in turn lead to the build-up of heavy metal in the soils
• The cost and time expended on certification where this is sought.

Question 21

What is the biodynamic viticulture approach based upon?

Answer 21

Biodynamic viticulture is based on the work of Rudolf Steiner and Maria Thun.

Question 22

What is biodynamic viticulture?

Answer 22

It includes organic practices but also incorporates philosophy and cosmology, regarding the farm as an organism and seeking to achieve a balance between the physical and higher, non- physical realms. The vineyard soil is seen as part of a connected system with the planet Earth, other planets and the air.

Practitioners adapt their grape growing practices to coincide with the cycles of the** planets, moon and stars.**

Question 23

What is the biodynamic calendar?

Answer 23

Maria Thun developed calendars to advise grape growers on root, leaf, flower or fruit days, which indicate the best days for certain activities.

Question 24

Give two examples of how biodynamic practices coincide with lunar and planetry activity?

Answer 24

• When the moon is ascending, a summer mood is evoked, sap is rising and therefore this is an appropriate time to take cuttings for grafting, but pruning should be avoided.
• When the moon is descending, a winter mood is evoked, and roots are favoured: this is the best time to plant vines or to prune.

Question 25

What is meant by dynamising in biodynamic viticulture?

Answer 25

This is the action of stirring the contents of the horn into water (creating a vortex and then reversing it) so that the water is said to memorise the power of the preparation, which can then be passed on to the vineyard.

Question 26

What is preparation 500 in biodynamics and what is the aim?

Answer 26

Horn Manure
* Cow manure is stuffed into a cow’s horn and burying the horn in the soil throughout the winter.
* It is then dug up and the contents are dynamised.
* This preparation is then sprayed onto the soil as a homeopathic compost
* It is believed to catalyse humus formation.

Question 27

What is preparation 501 in biodynamics and what is the process?

Answer 27

Horn Silica
This is made by filling a cow’s horn with ground quartz (silica) and burying it for six months. It is also then dug up, dynamised and sprayed onto the soil.
It is thought to encourage plant growth.

Question 28

What are the biodynamic preparations 502-507?

Answer 28

Preparations 502-507 are for compost which is enhanced and enlivened.

• 502; Yarrow blossoms
• 503; Chamomile blossoms
• 504; Stinging nettle
• 505; Oak bark
• 506; Dandeloin flowers
• 507; Valerian flowers

Each of these medicinal herbs are transformed through a unique process of fermentation. They are added in small quantities to the compost pile just after it is built, and again after it is turned.

Question 29

What is ‘ashing’ in biodyanamic viticulture?

Answer 29

Spreading the ashes of burnt weed seeds or harmful animals (e.g. rats or sparrows) on the vineyards to ward off these hazards.

Question 30

What is the most common certification body for biodynamic grape growers

Answer 30

Demeter

Question 31

How does a grower apply for certification in biodynamics?

Answer 31

The standards for biodynamic viticulture include organic certification of vineyards as a baseline, but then goes on to specify the principles that should be followed. Each national association interprets these in the light of local circumstances.

Question 32

What are the key features of Regenerative Viticulture?

Answer 32

• Regenerative viticulture aims to restore a vineyard site to a functioning agroecosystem with ‘ecosystem services’ to improve resources and limit inputs.
• Soil health is a top priority. Restoring the health of the soil will improve the health of the entire vineyard.
• Biodiversity—above and below ground—is essential to a functioning agroecosystem.
• Grape growers improve their well-being by reducing the cost of synthetic inputs and limiting their exposure to harsh chemicals.
• Carbon sequestration, aims to limit the impact on the environment and reduce viticulture’s carbon footprint.

Question 33

Why do the practices of regenerative viticulture differ between different regions and vineyards?

Answer 33

In practice, regenerative viticulture will look different in each vineyard because each site represents a unique system with idiosyncratic needs. Regenerative grape growers can draw from many different practices in order to create a self-sustaining agroecosystem.

Question 34

Name a few key methods in the ‘regenerative toolkit’.

Answer 34

• Cover crops, mulching
• Compost
• Biochar
• Agroforestry, biological corridors
• No or reduced tilling, irrigation
• Incorperating animals

Question 35

What are the advantages of regenerative viticulture?

Answer 35

• Soils are rehabilitated, decreasing the need for synthetic inputs.
• Carbon is sequestered, helping to fight climate change.
• Vineyards become more resilient, limiting the impacts of climate change.
• Biodiversity improves along with animal welfare.
• The lives of grape growers improve through less exposure to chemical inputs.

Question 36

What are the disadvantages of regenerative viticulture?

Answer 36

• It’s not legally defined, so claims by grape growers may be exaggerated.
• Growers need to experiment to figure out the best approach in their vineyard, which can take time, resources, and prolong the process.
• Once a plan is established, results take time, which can make the transition more difficult and costly (long-term investment)
• Producers cannot rely on inputs in case of disease or climate pressure, which may reduce yields.
• Certifications cost money, which can be a barrier.

Question 37

Give an example of a certification body in regenerative viticulture. What is the certification process?

Answer 37

Regenerative Organic Alliance (ROA).

When certifying a producer, the ROA measures things like soil health, animal welfare, and human empowerment.

Question 38

What is precision viticulture?

Answer 38

A branch of precision agriculture, makes use of data collected from the vineyard (soil, vine vigour, topography, plant growth) to respond to changes from plot to plot and from row to row.

Question 39

What data is used for precision viticulture, and how is it collected?

Answer 39

• The data is collected by sensors either on aircraft (‘remote’) or mounted on a tractor or harvester in the field (‘proximal’).
• Geospatial technology such as global positioning systems (GPS) and **geographical information systems **(GIS) allows the data to be presented visually in the form of maps.
• The data collected can be about the composition of soils, the rate of growth of the canopy etc.

Question 40

What are the steps involved in precision viticulture?

Answer 40

1. Collect data via aircraft (remote) or machinary in field (proximal).
2. Convey data in maps through geospatial technology such as global positioning systems (GPS) and geographical information systems (GIS).
3. Interventions in the vineyard are then targeted in the light of the data collected (variable-rate application technology.)

Question 41

What is variable-rate application technology in precision viticulture?

Answer 41

VRT uses data and automation to apply fertilizer, crop protection products, seeds and even irrigation water at different rates in different locations without a grower having to change application rates or make multiple passes manually.

Question 42

What is the aim of precision viticulture and variable-rate application technology?

Answer 42

The idea is for all key interventions to be carried out precisely with the aim of producing the best quality and yield, reducing environmental impact and, where possible, reducing costs on treatments.

Question 43

Give three examples of precision viticulture in practice.

Answer 43

• Changing the rootstock halfway along rows of vines as the soil gets more fertile
• Increasing levels of leaf-stripping in areas showing particularly high vigour
• Systematically controlling treatment application rates or irrigation rates.

Question 44

What are the advantages of precision viticulture?

Answer 44

• Detailed understanding of variations in the vineyard that affect yield and quality between and within vineyards
• Ability to tailor a wide range of interventions (choice of variety and rootstock, canopy management, treatments, harvest dates) to individual blocks or even rows of vines, with the aim of improving yields and/or quality.

Question 45

What are the disadvantages of precision viticulture?

Answer 45

• Initial cost of remote data collection
• Cost of sensors and software and of either consultancy or trained staff to interpret the data and make interventions in the light of it.

For these reasons, precision viticulture is only an option in large scale viticulture or on high-value, smaller estates.