Viticulture Notes.

Viticulture Notes by Reno Spiteri.

A top quality grape cluster.
Aglianico from Campania, Italy.

It is a sacrosant fact, that is advocated by most wine professionals that high quality wine can only be produced from high quality fruit. This means that great wines and top quality wines are made in the vineyard, in fact 80 per cent of quality winemaking happens in the vineyard. There ar a host of factors, both in the vineyard as well as in the winery that can effect the final product as it goes through the various procedures and is finally bottled and sealed. Even so, some wines require further aging in the bottle, in some cases even for years rather than months, in adequate and temperature controlled cellars before they are released for sale to the consumer.

Prime grapes for fine white wine.
Fiano di Avellino.

Many believe that the whole character of wine can be achieved in the winery, through modern equipment and new techniques, or through age-old traditional winemaking practices. Others including myself, believe that professional viticulture, terroir, and the climatic conditions during a specific year are of the utmost importance to obtain a prime, end-finished product. It is impossible to produce a top quality product from sub-standard raw material, and as was already stated, and for the sake of repeating myself, good quality wine can only be made with, and from good quality fruit, this is in our case the grape.

Typical vineyard.

The production of good quality grapes depend on many factors. The terroir and how the vines are grown and maintained through the season are vital issues. Viticulture, otherwise known as the growing and cultivation of vines for winemaking, is strongly affected by the terroir or the environement in which the vines are grown. Terroir involves the soil; the climatic conditions of the country, region, and vineyard location, that is, the macro and micro climate elements are of vital importance; the vineyard location and aspect.

A perfect vine growing season for the production of the finest grape yield would invariable involve, and necessitate:
- Cool, wet winters to provide plenty of ground water when the vines are dormant;
- Lack of rain or frost after the first warm days of Spring and lack of strong winds that would play havoc with the canopies and the flowering season;
- Fruit yield reduced from the vines to ensure only a moderate crop yield of the best grape bunches;
- Mild days and cool nights all Summer, with long hours of sunlight,  no rain or heat waves;
- Vines minimally irrigated and moderately stressed. Adequate green pruning of stalks, excessive leaf growth, and sub-standard grape clusters;
-Warm dry days preceeding and during harvest.

Prime Merlot Clusters.

Also of importance are:
- the application of organic amendments to the soil in the vineyards. A soil amendment is any material added to a soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration and structure. The goal is to provide a better environment for roots
- and the adequate and timely use of pesticides.


The final quality of the grapes are greatly influenced by the combination of all these elements, which invariably are responsible for the total natural and human environement in which the vines grow.

Chardonnay Grape Clusters.

It is a well known fact among viticulturists that certain grape varieties produce their best fruit when planted in certain specific soils. For example Chardonnay enjoys calcrous, chalky or limestone soils; Merlot grows and thrives best on clay soil; whilst Cabernet Sauvignon produce its best fruit on sandy and gravely soil.

Barolo terraced vineyards.

Well drained soils are essential, hence the reason why the best vineyards are planted on terraced plantations or along the sloping sides of valleys, but nevertheless the vines require water to thrive, therefore the water retention quality of the soil and the underlying ground structure is also of the utmost importance when one chooses the location for the planting of vineyards.



Agriculturally poor soils ar often considered to be best for vine cultivation as the vines will be forced to grow their roots long and to send them further deep into the ground in search of moisture. Consequently they find and  absorb different minerals, trace elemenets and nutrients which are not available further up.

Deeper roots make the vines to be less likely to be adversely affected by severe cold winters, as well as they enable the vines to withstand long dry spells and hot Summers.

Indegenious grape varieties grown in hotter climates require less water than grape varieties that thrive in cooler climates. Rootstocks and clones are developed and chosen to suit the soil and environement where the grapes are to be grown.

SO WHAT WOULD A YEAR IN THE VINEYARD ENTAIL: After all the above aspects of viticulture are studied, researched and taken into account, what remains is to discover what a year in the vineyard with the viticulturist would entail:

WINTER: Winter, when the vines are dormant entail the professional and skilled pruning of the vines.There are four basic choices of pruning: Cane pruning the most skilled; Spur-pruning easier and quicker; Machine pruning - effectively spur pruning but done by pruning machines and which is followed by a certain amount of further hand-pruning; and Minimal pruning - effectively no pruning at all during winter, which is not recommended or encouraged as this will give inferior bud growth.

SPRING: Planting - the optimum time for planting is early spring as the ground is starting to warm up yet still retains good moisture; Foliage Sprays - lime sprays are applied to guard against fungal desease; Working the soil - to avoid excessive use of herbicides to control unwanted weed or excessive grass growth; Canopy trimming and training - directing the new growth to establish the balance of the vine and to expose adequately the grape bunches to sunlight.

SUMMER: Irrigation - this period of flowering and fruit-set is a critical time in which the vine needs warm and calm weather, and in which the itrevention of the grower is limited. Irrigation will begin at this time in dry regions. Vine Maintenance - foliage spray by the Bordeaux mixture or other approved substances; Trimming the vine - canes to be trimmd and foliage raised and attached to the trellis wires to allow maximum sunlight to reach the leaves and grapes. Working the soil - the area under the vines is not to be disturbed, but the soil between the rows of vines is sometimes lightly plowed to prevent runoff and to conserve moisture. Pest Control - caterpillars. moths, snails, and toward ripeing, birds have to be controlled.

AUTUMN: Harvest - machine harvesting or the gentler, slower, more controllable hand-picking of quality grapes will be carried out as decided by the viticulturist and the oenologist at this time. Application of Post-harvest sprays - at about 50% leave fall, sprays are applied to kill mildew spores that would otherwise establish themselves on the vine during winter. Working the soils and application of the fertilizers - manure and fertlizers are worked into the soil and the soil is banked up under the vines to protect them from frost. Vineyard Maintenance - between the end of harvest and the commencement of pruning much vineyard maintenance is required, to keep the vineyard in tip-top condition, clean and neat, with all cuttings removed and disposed of or chopped and incorprated into the soil; trellising is checked and repaired; broken wiring renewed. etc.

Vines have been found to grow best between the latitudes of 30 to 50 degrees North and 30 to 50 degrees South. The average yearly temperature must not be  below 10deg C, and the ideal is an average of 14Deg C. Too much heat will result in small grapes with toigh skins and high potential alcohol with low acidity. Too little heat will rsult in grapes high in acidity and short on sugar and flavour.

Climate change is having an effect on vine growing worldwide. Australia in the Southern Hemisphere and countries in the Northern hemispher like for example Spain  have been subjected to droughts with the resultant lack of water for irrigation purposes.This has meant that rootstock varietals and viticultural methods shall have to be looked at and re-assessed in the present traditional growing areas. Climate change have also had its benefits in northern countries which traditionally lacked the required sunshine and temperatrures, and which are now seeing a massive improvement in their vine growth and grape quality. Such countries are England, Switzerland, Germany.

Of all the climatic conditions frost is the  most feared. Frost in late Spring will damage new shoots, thus reducing the size of the crop at harvest.

Locations are of the utmost
importance.

Locations and aspects of vineyards are of the utmost importance as vines require the ultimate amount of available sunshine in any location. The best aspects are normally South facing slopes or terraced locations. This causes the vines to recieve more concentrated rays from the sun. Temperatures are important to the well being of the vine, but sunlight is also a vital factor. Warm daytime hours and cool or cold nights are beneficial and allow the vines to rest at night and consequentially raise the acid content of the grapes.

Winds can also cause problems for the vines. Too much wind can cause vines to close down thus halting the process of photosynthesis. Strong windscan damage the vines by breaking off stems and leaves. a little wind or slight breezesare sometimes needed and desired to dry out the vines and leaves when wet and thus reduce the danger of rot.

Other important factors that would affect the quality of the grapes are vine densities, vine training, canopy design and management, pruning, irrigation, yields, green picking of the grapesto reduce yield and vine green pruning.

Desease and pests are other variables which need to be addressd and watched for continuously.

The overriding attribute of a good terroir is balance. Balance in the soil; balance in the climate; and balance in its treatment.

Fine wine.

Making outstanding wine is not an easy matter. In the vineyard the selection of the most suitable varietal on the most suitable rootstock, for the prevailing conditions and the type of wine that is intended to be produced is of the greatest importance. Many varieties of grapes are used to produce wine. The majority are based on the grafting of scones of mainly European varieties of the species Vitis Vinifera on to American rootstock. Such grafting began in the nineteenth century after all vineyards in Europe and all over the vine growing world of the time were destroyed by the louse Phylloxera which was inadvertently imported into Europe from the United States of American  with American rootstock that was infested with this tiny bug. This practice has continued all over the world ever since to elimate another very costly outbreak.

Grafting is also used on existing vines, to replace varietals which may not be performing well in the prevailing conditions, and/or which might not be popular and in demand.

Viticulturists are well aware of the dangers imposed on their vineyards through various desease and pests, that appear in vine from time to time and which may attack vines as well as the grapes wiuth disastrious results. Some of these deseases and pests are named herewith for reference:

Botrytis Cinerea.

- Botrytis Cinerea or rot appears in avariety of forms, one of which is highly priced. This is called "Noble Rot", but if this becomes grey rot or black rot, the desease will be disastrious for the grapes.

- Leaf Roll Virus is spread by the mealy bug and through infected cuttings.

- Coulure is the non-proliferartion of some of the blossoms, causing the grapes either to fall off or never to develop.

- Eutype or Dead Arm Desease is a fungal desease which affects the trunk and canes of the vine and causes them to die slowly.

- Fanleaf Virus causes the leaves and shoots to be deformed with poor fruit set and serious reduction in yield.

- Millerandage is another result of cold, wet vweather at flowering, causing poor fruit set which prevent some of the berries from developing.

- Nematodes are minute round worms which feed on the roots of th vine.

- Powdery Mildew attacks the green parts of the vine and develop white spores which have a powdery appearance.

- Downy Mildew known as Peronospera also attackes the green parts of the vine in particular the leaves and cause them to fall off. This reduces the photosynthesis causing late ripeing, reducing yields and lower sugar content in the grapes.

Phylloxera Adults and eggs.

-Phylloxera Vastestrix is a small and very tiny louse-bug which originated in the USA and devastated the vineyards of Europe and the rest of the world other than the USA whose generic and indegenious vines were resistant to it. The existence and emergence of Phylloexera Vastetrix  in Europe was first recorded in 1863. This bug attacks the roots of the vine and is letal on Vitis Vinifera vines.

The Phylloxera bug.

- Pierce's Desease is a bacterial infection which kills vines affected by it. There is no known cure for it at the moment. It is mainly prevailent in the Napa and Sonoma valleys and in Southern California, but might find its way to other countries if careful attention is not given to imported rootstock and even other plants.

As was stated at the beginning of these notes, great wine is produced in the vineyard, and that fine wine can only be produced from great and high quality fruit. As can be seen from the above, this is not an easy matter as the work and expertise involved is considerable as well as very expensive. Great and fine wine come at a cost, but the investment must start in the vineyard. That is the only way that the oenologists can finally produce such wines in the winery for us to enjoy.

Harvested prime grapes.

One of the very finest and most
expensive wines in the world