MAY 1997
E. Archer, Department of Viticulture and Oenology, University of Stellenbosch
1. INTRODUCTION AND BACKGROUND
The request for planning Kleine Uitzicht was received from mrr. Den Dulk during May 1996. The farm is situated on the rolling foothills of Polka Draai on slopes ranging from easterly through south to westerly on predominantly Estcourt, Klapmuts and Kroonstad soils with pockets of higher potential Tukulu and Oakleaf soils. Although these soils are classified as medium potential for viticulture, small areas of higher potential soils also occur. With correct soil preparation (drainage, depth of shift delving, etc.) these soils can be ameliorated to be suitable for vines.
Eventually the property will produce its own red wine and, therefore, the vineyard plan is focussed on the production of the highest possible quality wine. It was agreed that this planning must be detailed with all the important aspects of growing winegrapes such as terrain, scion and rootstock choice, vine spacing, trellising, pruning, canopy management, cultivation, irrigation, fertilisation, etc.
2. SOIL RELATED ASPECTS
2.1 Soil map and soil properties
A soil survey of Kleine Uitzicht was done by D. Saayman during August 1996. A copy of the soil map, on a reduced scale, is included as Fig. 1. The soil properties are described in detail in the soil report written separately by D. Saayman. In this report aspects concerning soil preparation will be dealt with.
2.2 Soil preparation
Soil preparation on Kleine Uitzicht will be a complex operation because of the variation in soil types, which occur on the property. The method of preparation will need to be adapted for each block and care will have to be taken to ensure that the correct implement is used and the correct depth is attained in each soil type. Specific care must be given to soil moisture content during preparation because too dry or too wet soils will seriously limit the efficacy of soil preparation procedures. Although no information concerning the chemical analyses of these soils is available, it can be expected that in some cases generous amounts of lime and phosphorus will be necessary to ameliorate the soil. The situation must be verified by representative sampling. It will probably mean that in most cases soil preparation must be carried out in two directions. The second cultivation should always be in a predominantly downslope direction in order to create subsoil drainage channels. When incorporating ameliorants, care must be taken not to plough the subsoil to the surface, but to obtain mixing by letting the topsoil sift into the deeper layers. Modern im
plements are designed to achieve this, but the results should be verified at the start and end of the ploughing process. Because of the complexity of soil preparation on Kleine Uitzicht, it is strongly recommended that the specific procedures for each block be discussed with Dawid Saayman (tel. 808 4789).
2.3 Cultivation
Special care should be taken not to allow wheeled vehicle traffic on especially the less stony, hydromorphic or strongly structured soils after preparation or even during the first year after planting, because recompaction will nullify virtually all that has been achieved during the preparation process. If traffic is inevitable before planting, the future vine rows must be clearly marked out and an absolute minimum amount of traffic allowed only in the future inter-row spaces.
A good stand of fibrous cover crop (triticale, rye or oats) during winter, that is killed by means of a "soft" herbicide before budding and left on the surface, is considered a very efficient practice to protect the improved soil structure that was created by the deep preparation process, to protect the soil surface against erosion during winter and to maintain the organic matter content of the soil. This practice is especially important in the case of the less stony soils. Ideally, soil preparation should be done before winter, the cover crop established and the new vines planted the following spring in the dead cover crop mulch. The benefits of this practice outweigh the disadvantages, viz. hiding places for snails and snout beetles.
A biological/chemical weed control programme is recommended for Kleine Uitzicht. A winter cover crop must be sown in every row during autumn (early April) and top dressed with 50 kg super phosphate per ha. The cover crop must be killed with a contact herbicide before budding starts and it must be flattened to create a mulch. A typical herbicide programme after the plastic strips became non-functional, is as follows:
3. GUIDELINES FOR A CULTIVAR PLAN FOR KLEINE UITZICHT
Due to the particular aspect of Kleine Uitzicht only high quality (noble) winegrape cultivars are taken into account for planting. The choice of a specific cultivar for a specific site is determined by the characteristics of the cultivar, topography, slope and altitude. Furthermore, specific clones of a cultivar are used to accentuate the complexity of the wine. White as well as red cultivars are used to create a user friendly wine spectrum. It is accepted that, eventually, all wine will be sold through the bottle. Topography affects not only the temperature during ripening but also the occurrence of delayed budburst. Normally lower day temperature prevails on the top of hill sites but the night temperatures are higher than for sites in the valleys. Bud dormancy, therefore, is frequently not completely broken on higher, convex sites resulting in delayed budburst. Cultivars differ with regard to susceptibility to delayed budburst but normally red winegrape cultivars do not have a problem in this regard. With the possibility of using "Dormex" or Partner G this problem diminishes. Although high lying sites are characterised by lower day temperatures whereby cooler ripening conditions prevail, the effect of high velocity wind on vine performance is a consideration on Kleine Uitzicht when certain sites are chosen for certain varieties. An important fact that needs consideration is that vigour and prolonged vegetative growth adversely affect grape and wine quality. Cultivation practices such as vine spacing, trellising, pruning, fertilisation, irrigation, etc. must therefore be aimed at moderate shoot growth, which must terminate between veraison and ripening. The essential balance between vegetative and reproductive growth is more easily obtainable on lower potential soils than on higher potential soils and in this regard Kleine Uitzicht is fortunate.
A further important consideration for an ideal cultivar plan is the contemplated wine style, which is necessary to meet the requirements of the targeted market. In the case of Kleine Uitzicht this market is defined as mainly the top red wine market. Although certain areas on Kleine Uitzicht may lend itself to the production of other cultivars, this planning focuses on the so-called "big seven" cultivars in the South African industry.
The lack of complexity in many wines is frequently a problem in the South African wine industry. The complexity of a wine can be augmented by using grapes from more than one terrain or by using more than one clone per cultivar on the same terrain. The combination of fruity, grassy, raspberry-like, etc. clones in a specific block is the origin of good wine complexity. In an endeavour to maximise the complexity of Kleine Uitzicht wines, more than one clone per cultivar should be used. The existing cultivar plan for Kleine Uitzicht is indicated in Fig. 2.
3.1 Scion cultivars which can be considered
3.1.1 Cabernet Sauvignon
This is the most famous red winegrape cultivar in the world and was introduced to France by the Romans. For ages Cabernet is the most important component of the world famous Bordeaux blends. It is a vigorous cultivar with no affinity problems with the known, commercial rootstocks.
Budding : Second half of September
Flowering : First half of November
Ripening : End of March (Schleipp clone 2-4 weeks earlier)
Crop : 6-12 t/ha
Average sugar concentration : 22-24 °B
Average acid concentration : 6,6-7,1 g/l
Wine quality : Premium
Cabernet Sauvignon is resistant to diseases and is equally well adapted as a cultivar wine or for the use in blends. A wide variety of clones of Cabernet Sauvignon are available and the following clones were selected for possible use on Kleine Uitzicht:
CS 163 C - early ripening, grassy sometimes minty, dark colour, crop control sometimes necessary, from Germany.
CS 1 C - relative early ripening, strong grassy/berry, good colour, from Davis.
CS 20 C - relative middle ripening, strong berry, dark colour, from VORI.
CS 16 C - relative middle ripening, complex fruity grassy/berry, very good wine, from V.O.R.I.
CS 18 A - relative middle ripening, very typical cultivar character, grassy, from France.
CS 15 C - relative middle ripening, strong berry/fruity, good wine, from France.
CS 169 A - relative middle ripening, strong grassy, green-pepper, very good clone, high production, from France.
CS 27 A - relative late ripening, strong berry, very good wine, from Durbanville.
CS 14 A - relative late ripening, very typical complex/grassy, full wine, from VORI.
CS 46 C - relative late ripening, strong typical cultivar character, nutty/spicy from KWV.
3.1.2 Merlot
This cultivar arrived in Bordeaux early in the 18th century from an unknown origin. It became famous for its adaptability to blend with Cabernet Sauvignon although cultivar wines from Merlot also became renowned. The cultivar is a moderate grower and combines well with commercial rootstocks. It is very susceptible to water stress during ripening.
Budding : Beginning of September (8-15 days before Cabernet)
Flowering : First half of November (5-7 days before Cabernet)
Ripening : First half of March 2-3 weeks before Cabernet)
Crop : 8-12 t/ha
Average sugar concentration : 24 °B
Average acid concentration : 6-7 g/l
Wine quality : Premium
The cultivar is resistant to diseases. Traditionally it is blended with Cabernet Sauvignon but on its own it produces very fruity, full, soft wines which can be drunk early but is equally able to mature well in the bottle. A wide variety of clones of Merlot are available and the following clones were selected for possible use on Kleine Uitzicht:
MO 3 - relative early ripening, typical soft grass/berry, well balanced, from Italy.
MO 36 A - relative early ripening, typical pronounced berry, good colour, well balanced, from Switzerland.
MO 192 - relative middle ripening, soft berry/grassy, well balanced, from Italy.
MO 343 A - relatively middle ripening, strong fruit, well balanced, from France (not yet free from harmful viruses).
MO 348 A - relatively middle ripening, grassy/berry, from France.
MO 12 - relative late ripening, soft berry/grassy, very good wine, from Italy.
MO 9 - relative late ripening, strong fruit, dark colour, well balanced, from Italy.
3.1.3 Cabernet franc
This cultivar is closely related to Cabernet Sauvignon and together with Merlot, these three cultivars form part of the famous blended wines of Bordeaux. The wine from Cabernet Franc resembles that of Cabernet Sauvignon but is softer and consumable at an earlier age. For this reason it is as well-known as Cabernet Sauvignon in Europe and in some regions in Italy it is preferred above Cabernet Sauvignon wines. It has very good compatibility with commercial rootstocks although with some clones of 101-14 Mgt certain problems may occur. Cabernet franc is a strong grower with an upright comportment.
Budding : Second half of September (3-5 days before Cabernet Sauvignon)
Flowering : First half of November (same as Cabernet Sauvignon)
Ripening : End of March (± 4 days before Cabernet Sauvignon)
Crop : 10-14 t/ha
Average sugar concentration : 22-24 °B
Average acid concentration : 4-6 g/l
Wine quality : Premium
Cabernet franc is susceptible to oïdium and downy mildew and a precise disease control program must be followed. It is well adapted in wind and resistant to botrytis. There are only six clones available and from these the following were selected for possible use on Kleine Uitzicht.
CF 1 A - Strong berry/grassy, from VORI.
CF 1 D - Well balanced wine, typical cultivar character, from Nietvoorbij.
CF 5 - Strong berry/grassy, very good wine, from Italy.
CF 13 C - Strong grassy, full bodied, well balanced, from Australia.
CF 3 A - Typical cultivar character, well balanced, from Italy.
3.1.4 Malbec
This cultivar is well-known in France where it is cultivated extensively under the name
Côt in the Loire Valley as well as in the Midi region since the 1700s. Little is known of
its performance under South African conditions, except that it grows well and have
high crops of very good quality. It blends well with Cabernet Sauvignon because of
soft tannins and a well defined fruitiness. Malbec promises to be one of the range of
high quality cultivars in South Africa and it is well adapted to local conditions. In this
country the wines of Malbec are unique in odour and taste which means that is can
be marketed as a cultivar wine or blended with the other top reds.
Budding : First half of September
Flowering : Second half of October
Ripening : Third quarter of February
Crop : 10-14 t/ha
Average sugar concentration: 23-25 °B
Average acid concentration : 5-6,5 g/l
Wine quality : Premium
MC1 : Average production, above average vigour, strong berry/fruity, soft somewhat lower set, earlier than the other clones, from California.
MC71 : Average production, above average vigour, strong berry/fruity, soft, produces better than the other clones because of a better berry set, from Argentinia.
3.1.5 Petit Verdot
This cultivar is of French origin where it is grown in the Medoc region for many years. Little is known of the performance of this cultivar under South African conditions, but the wines that were made have shown good colour and aroma, are rich in tannins with a very good potential for ageing. Petit Verdot is totally resistant against botrytis and for this reason it is always harvested last in Medoc. The French regard the wine quality of Petit Verdot as high and together with a good crop and easy viticultural aptitudes, they do not hesitate to recommend plantings of this cultivar. There are only two clones which can be used.
PR400 medium vigour, strong berry/nutty character, good tannin structure, very good colour, from France.
PR8719 medium vigour, very fruity, strong tannins, very good wine, from France.
Budding : First half of September
Flowering : Second half of October
Ripening : Mid February
Crop : 10-14 t/ha
Average sugar concentration : 23-25 °B
Average acid concentration : 4-6 g/l
Wine quality : Premium
3.2 Rootstock cultivars which can be considered
Although more than 80 rootstock cultivars are available in South Africa only 10 are used commercially. The reason for this is that the experience with the remainder of the cultivars is limited and farmers are reluctant to "take a chance" with rootstocks. Subsequently, only the rootstocks that can be considered for Kleine Uitzicht will be discussed.
3.2.1 99 Richter
This rootstock is by far the most popular one in South Africa and it has the following properties:
Affinity : Outstanding
Vigour : Very good
Resistance against :
- Phylloxera = Outstanding
- Nematodes = Good
- Phytophthora = Very poor
- Lime = Good
- Salinity = Moderat
- Drought = Moderate to good
R99 is well adapted to compact soils although it prefers well drained, deep, structureless soils. Under certain conditions it induces too vigorous growth in the scion cultivar, thereby creating adverse conditions for high quality production. Wet soils, especially where Phytophthora cinnamomi may be present should be avoided. Although various clones of R99 are available no proof exists that one performs better or worse than the other does.
3.2.2 Richter 110
This rootstock possesses much the same properties as Richter 99 with the important difference that it is much better drought resistant and is a moderate grower inducing moderate growth in the scion cultivar. It is preferred above Richter 99 on dry soils with medium depth.
3.2.3 101-14 Mgt
Next to Richter 99 it is the most important rootstock for winegrapes in South Africa and it have the following properties:
Affinity : Very good although problems sometimes occur with certain clones of certain cultivars
Vigour : Moderate
Resistance against :
- Phylloxera = Very good
- Nematodes = Good
- Phytophthora = Moderate
- Lime = Good
- Salinity = Moderate to good
- Drought = Moderate
This is a rootstock with moderate vigour and has the reputation that it induces earliness in the scion cultivar. Genetically it possesses a more shallow root system which accentuates its adaptability on more shallow soils (30-50 cm soil depth). It combines perfectly with Cabernet Sauvignon because it curtails the vigorous growth of this cultivar. Because of its moderate resistance to drought, vineyards in which this rootstock is used must be irrigated once or twice during the growing season.
3.2.4 Ruggeri 140
This rootstock is a cross between Vitis Berlandieri var. Rességuier no. 2 and Vitis rupestris var. du Lot and was produced early in the 20th century by Ruggeri in Palermo, Sicilia. It is a hardy, strong growing rootstock, which performs very well under dry conditions. Of all the rootstocks Ruggeri 140 possesses the best resistance against drought, therefore no irrigation is necessary when this rootstock is used. It has the following properties:
Affinity : Generally very good
Vigour : Good to very good
Resistance against :
- Phylloxera = Outstanding
- Nematodes = Moderate to sufficient
- Phytophthora = Sensitive
- Lime = Outstanding
- Salinity = Good
- Drought = Excellent
The clone that should be used is Ru 354 B.
3.3 Principles for choice of terrain
A whole range of soil and climatic properties dictates the suitability of a specific site for the cultivation of high quality grapes. The major high quality cultivars each possess certain properties, which make it distinguishable from one another. These properties must be emphasised through terrain choice in such a way that the highest possible quality is obtained from each cultivar. South Africa is basically a hot climate country in which close consideration is necessary to use the coolest possible localities for the production of high quality wine. Generally, southerly orientated slopes are cooler than northerly orientated slopes but in this regard prevailing wind plays an important role. Al slopes accessible by the cool south-westerly breeze during summer are suitable for high quality cultivars.
During daytime in the summer higher localities is cooler than lower localities, which are an important climatical factor for optimal ripening. As a general rule, therefore, cultivars with fruity flavours prefer higher localities. Lower slopes are generally better provided with soil water than higher slopes, thus inducing more vegetative growth. As a general rule, therefore, cultivars with grassy flavours prefer lower localities. Because the soil water of higher localities generally diminishes quicker than that of lower localities, early ripening cultivars should generally be planted on the higher slopes.
3.3.1 Terrain for Cabernet Sauvignon
This cultivar is characterised by a wide range of clones producing a wide range of flavours, e.g.: grassy, berry-like, blue gum, minty, raspberry-like, etc. This is the main reason why a mono-clone culture of Cabernet Sauvignon should be avoided. As many clones as possible (at least 2 per ha) of this cultivar should be used to induce complexity in the wine.
Cabernet Sauvignon is a late ripening cultivar, which prefers warm day temperatures and cold night temperatures during ripening to optimise flavour and colour synthesis. Because of the late ripening, localities with sufficient soil moisture are very important to avoid the hard ripening conditions prevailing on dry soils. The best terrain for this cultivar is thus found on lower northerly slopes. The high vigour normally expected on these terrains is sufficiently curbed by using either R110 or 101-14 Mgt as rootstocks. The blocks on Kleine Uitzicht where Cabernet Sauvignon should be planted are indicated in Fig. 3.
3.3.2 Terrain for Merlot
The most important property of Merlot is its unique soft and fruity wines. To enhance this character of Merlot it should not be planted in hot localities in order to avoid quick, forced ripening. This cultivar is very susceptible to drought. Exposed, middle to higher northerly to easterly slopes with sufficient soil moisture is suitable for Merlot especially since these localities ensure sufficient colour synthesis. Deep, moist, cool soils are best for this cultivar. Evidently, provision must be made to irrigate this cultivar when necessary. In an endeavour to alleviate the problem of drought susceptibility, Ruggeri 140 or Richter 110 should be used as rootstocks for Merlot. To ensure complexity in the wine, at least 2 clones per ha should be used. The blocks on Kleine Uitzicht where Merlot should be planted are indicated in Fig. 3.
3.3.3 Terrain for Cabernet franc
The available clones of Cabernet franc do not differ much from one another in terms of wine flavour. The existing differences, however, can be enhanced by different terrains. It is also a late ripening cultivar (± 4 days before Cabernet Sauvignon), therefore localities with sufficient soil moisture during ripening are preferred for this cultivar. If planted on the same slope as Cabernet Sauvignon, it should always be planted above to enable harvesting at optimal ripeness especially if large vineyards of Cabernet Sauvignon are planted on Kleine Uitzicht. The best rootstock for Cabernet franc is Richter 110.
3.3.6 Terrain for MalbecAlthough not much is known of terrain preference of Malbec in South Africa it is already clear that Malbec adapts well to a wide range of conditions. The softer the conditions, the softer and fruitier the wine and therefore it is believed that Malbec will adapt very well to some localities in South Africa.
3.3.7 Terrain for Petit VerdotThis cultivar is f French origin where it s grown in the Medoc Region for many years. Little is known of the performance of this cultivar under South African conditions but wines that were made have shown good colour and aroma, are rich in tannins with a very good potential for ageing. Petit Verdot is totally resistant against botrytis and for this reason is harvested last in the Medoc. In the warmer inland areas of the Cape however, this variety is harvested first. The French regard the wine quality of Petit Verdot high and together with a good crop and easy agricultural aptitudes, they do not hesitate to recommend plantings of this cultivar. There are only two clones which can be used.
4. VINE SPACING
The main aim in viticulture is maximum interception of sunlight energy and the efficient conversion thereof into chemical energy thus producing the components necessary for size and quality of the crop. The efficiency by which this requirement is met is the foundation of the economic result of the operation on Kleine Uitzicht. Together with the trellising system, correct vine spacing is probably the main key through which this objective can be met.
Both too wide and too narrow vine spacing has important disadvantages. Too wide spacings cause unacceptable loss of sunlight energy. Too narrow spacings, on the other hand, cause unacceptable dense canopies and the creation of excessive canopy shade resulting in a direct loss of quality. Vine spacing is dictated by the potential of the soil for vigour. The higher the potential, the wider the in-row spacing and the lower the potential, the narrower the in-row spacing. This means that uniform vine spacing is seldomly possible for all blocks on a farm. Furthermore, this is the reason why the boundaries of vineyard blocks should as far as possible follow the boundaries between different soil types in an effort to avoid different in-row spacings in the same block.
Vine spacing also dictates the efficiency of root performance with respect to the uptake of water and nutrients. This root function is performed more efficiently in the case of high root density than in the case of low root density. The distribution of roots and, therefore colonisation of the soil by vine roots are directly related to vine spacing. The mesh of colonisation is small (root density is high) when narrow vine spacing is used and vice versa. The ideal is to associate high root density with enough cordon space for a balanced bud-load.
Idealisticly, between-row spacing is standardised on the whole farm and is dictated by the size of machinery. It should always be as narrow as possible. In this respect the gradient of slopes play an important role. In-row spacing is varied according to soil potential. The vine spacing for Kleine Uitzicht is indicated in Fig. 4.
5. TRELLISING
A correct trellising system compliments vine spacing in the aim to maximise the utilisation of sunlight energy. An important principle that must be satisfied at all times is that the trellis must always accommodate the vine vigour and never limit it. The trellis must, ideally, induce relatively thin vertical canopies and must be high enough to avoid too early topping (avoid excessive development of lateral shoots). A vertical trellis system with movable foliage wires is a requirement to minimise costs for canopy management. The Hedge trellis, which is proposed for Kleine Uitzicht, is depicted in Fig. 5 and the requirements for trellis material per ha are given in Table 1.
Wire position 1 has two parallel wires on both sides of the pole. The tension on these wires should enable movement to the higher position as well. The types of brackets, which can be used, are also depicted in Fig. 5. The wire brackets are self-made and therefore cheaper than the commercial ones. Furthermore, they have the advantage that shoots are not forced into a too narrow space as will be obtained with the other brackets. Shoots are positioned by moving the wires as indicated in Fig. 5.
The distance between the cordon and the first set of movable foliage wires is a function of prevailing wind and in the case of Kleine Uitzicht a distance of 25 cm is prescribed.
TABLE 1. Material requirements for a 4 wire Hedge trellis
|
|
Quantity per ha for row widths of |
|||
|
2,4 m |
2,5 m |
2,7 m |
3,0 m |
|
|
82 |
80 |
72 |
66 |
|
492 |
480 |
432 |
396 |
|
|
|
|
|
|
11 lengths |
10 lengths |
9 lengths |
8 lengths |
|
|
|
|
|
|
4,0 |
3,5 |
3 |
2,5 |
6. ESTABLISHMENT OF VINES
Proper planting holes must be made with a spade (breadth of the blade X breadth of the blade) and care must be taken that compaction of the walls and bottom is avoided at all costs. To accomplish this, a fork must be used to work down the walls and loosen the bottom of the planting hole. Special care must be taken to avoid desiccation of the vines during transport as well as during the planting process. The canes of the young vines are cut, retaining the most upright and strongest cane. This cane is cut back to two buds while cutting of roots is strictly prohibited (the main storing organ for reserves). The soil surface in the vine row must be kept free of any weeds especially during the first two establishment years. For this reason the use of
black plastic strips is recommended. The planting of vines is illustrated in Figs. 6 and 7. A planting programme for Kleine Uitzicht is proposed in Table 2.
TABLE 2. Planting programme for Kleine Uitzicht
Block no. Year of land Year of planting Year of first
preparation crop
9 2007 2008 2011 10 2001 2002 2005
12 2007 2008 2011
13 1997 1998 2001
14 1998 1999 2002 15 1998 1999 2002 16 1999 2000 2003
7. TRAINING YOUNG VINES
The aim of training young vines is to create a well balanced vine framework (roots, stem, cordons and bearing positions) for a minimum period of 25 years. Mistakes during this process remain a problem for 25 years and the training of young vines, therefore, must be done judiciously.
7.1 Bush vines
During the first winter after planting, the strongest and most up-right cane is cut back to two buds; the rest are cut cleanly. During the second growing season after planting, the shoots are allowed to grow as freely as possible. This is to ensure good root development. Tipping and/or topping are, therefore, avoided as far as possible and it is recommended that shoots hampering traffic must be loosely tied to a temporary stake. Suckering of weak shoots, which will not be used for the vine framework, is recommended.
During the second winter after planting the forming of the bush vine is started by allowing a certain number of arms (depending on vigour) to develop around the centre of each vine. It is important to try to lift the crown of each vine above the ground-level as quickly as possible, therefore it is recommended that these arms are pruned longer than normal; up to 3-4 buds per cane. These arms must be positioned symmetrically around the centre of each vine, even using water shoots. A total of three arms are developed on each vine during this winter.
During the third growing season shoot thinning is very important; retaining only the shoots which developed on the new arms as well as those which will be used to establish new arms. Tipping, to prevent wind damage, is done when an average shoot length of 45 cm is reached. Crop control is necessary during this period.
During the third winter after planting two new arms must be added to each vine to create a vine with five symmetrically positioned arms around its centre.
7.2 Trellised vines
The underlying principle of young vine training is the creation of well balanced cordons over the total length of the cordon wire. The total cordon wire must be covered with spurs resulting in approximately 16 - 20 shoots per running meter of cordon, in other words, 8 - 10 spurs per meter cordon. The process of training young vines must, therefore, be such that too long as well as too short internodes of cordon shoots are avoided, aiming at an internode length of approximately 6 cm. Ideal wine shape ensures ideal canopy density with minimal inputs for canopy management.
Although many variations of vine training procedures exist, the following procedure is recommended for Kleine Uitzicht: During the first growing season after planting the vines are left undisturbed. If the shoots impede normal cultivation practices they are loosely tied to allow traffic but not topped. This above-ground growth ensures good root growth because of the inherent balance between shoot and root growth. At the end of the first winter after planting the most upright and strongest cane is chosen and cut back to two buds. The rest are pruned cleanly. During the following growing season (2nd summer after planting) the so-called green shoot method is used to form the vines on the cordon wire.
When the average shoot length is 30 cm, the strongest and most upright two shoots are retained while the rest are removed. At this moment the weaker shoot is topped and both shoots are tied to a support (each vine is provided with a stake or piece of string attached to the cordon wire). The so-called stem shoot must be tied at every 30 cm interval. When the stem shoot by-passed the cordon wire by approximately 30 cm it is topped through the first node above the cordon wire and securely tied to this wire. The top three lateral shoots (not closer than 5 cm beneath the cordon wire) are retained and the rest of the laterals (as well as those developing from the rootstock) are removed. When the strongest two laterals reach an average length of approximately 30 cm they are bent down to the cordon wire, each to opposite sides of the stem, and tied to the cordon wire. When securely tied, the so-called spare stem shoot is removed. It is important to ensure the narrowest possible fork to avoid any gaps on the cordon wire and for this purpose the two cordon shoots may be crossed. The cordon shoots are intermittently tied (30 cm intervals) to the cordon wire and left to grow unhinderedly until the cordon shoots of adjacent vines by-passed one another by 30 cm. At this stage they are topped so that lateral shoots may develop stronger. When the stronger of these laterals reach approximately 30 cm length, they are tipped to enable the weaker ones to develop stronger. During the second winter after planting the lateral canes are spaced, and pruned back to one-bud spurs. The cordon canes are then treated with cyanamide to ensure an even budburst. The above-mentioned procedure is fully demonstrated in Addendum A. It is of utmost importance that the following crop control guidelines are followed:
Experience has shown that one trained labourer is able to handle two ha of young vines if he or she does the work continuously. E. Archer is willing to train a small group of labourers with the above-mentioned procedures if so requested.
8. CANOPY MANAGEMENT
If vine spacing and trellising are correctly done and a balanced bud-load is applied only minimal inputs are necessary for canopy management. Canopy management programmes are seen as the last option open to the viticulturist to avoid excessive canopy shade. Excessive canopy shade causes a decrease in bud fertility, sugar concentration, colour density, flavour and tartaric acid while it increases potassium concentration, pH and malic acid. It is, therefore, of paramount importance to avoid excessive canopy shade. The following canopy management programme is recommended for Kleine Uitzicht.
Shoot thinning - is done when the longest shoots reach 10 cm length; a second action is necessary 3-4 weeks later. Allow 16-20 shoots per meter cordon. For this approximately 40 man hours per ha is necessary.
Shoot positioning - is done once only when average shoot length surpassed the first parallel wires by about 20 cm.
Approximately 5 man hours per ha are needed becaus
of the movable wires.
Tipping - is done when the longest shoots start hanging over, in other words, approximately 30-40 cm above the top foliage wire. For this about 15 man hours per ha is needed. Never top.
Leaf removal - is done only inside the canopy in the cluster zone and no leaves on the exterior must be removed. For this approximately 40 man hours per ha is needed and it is done at berry touch phase. Leaf removal is only practised when needed - no leaves must be removed if it is not essential for optimal canopy density.
Removal of lateral shoots - if necessary, it should be done before veraison. Normally not necessary.
The above-mentioned canopy management programme is only a guideline. Adaptations to this will be dictated by the season and vigour of each block as well as by the wine style pursued.
9. WINTER PRUNING
If vine training is properly done, winter pruning is just a formality. It is important to maintain proper spacing of bearing units (8 -10 spurs per meter cordon) and to avoid any build up of spurs by employing renewal practices. The underlying principle is to create a continuous cordon over the total length of the cordon wire upon which bearing units are evenly spaced (±10-12 cm apart). Specific methods exist through which adaptations in bud-load can be made and if necessary this process will be guided by E. Archer if and when the need arises.
10. PEST AND DISEASE CONTROL
The basis of any chemical control programme is to spray as little as possible while not compromising on the efficacy of control. This is especially true for pests and, therefore, it is recommended that only spot spraying is done for pests when and where it occurs. No general sprays against pests are recommended. The disease control programme given in Table 3 is against the most important diseases and it must be adapted if and when other diseases occur or according to changes in the climatical conditions of a specific season.
TABLE 3: SPRAYING PROGRAMME FOR KLEINE UITZICHT
|
Spray No |
Pest/Disease |
Product |
Concentration/ |
Total vol. spray mixture |
Remarks |
|
Downy mildew |
Sancozeb |
200 g |
300 l |
Temperature too low for sulpher dust. |
|
Downy mildew |
Sancozeb |
200 g |
|
|
|
Downy mildew |
Sancozeb or Ridomil |
200 g or 270 g |
|
Favourable climate for downy mildew: Ridomil during bloom. Monitor mealy bugs. |
|
Oidium |
Sulpher dust |
15-20 kg/ha |
Additional treatment if necessary (22° C - 25° C). |
|
|
Downy mildew |
Sancozeb |
200 g |
|
|
|
Downy mildew |
Sancozeb |
200 g |
|
Botrytis spray only on susceptible cultivars (compact bunches). |
|
Downy mildew |
Sancozeb |
200 g |
|
Rainy weather: use Ridomil on susceptible cultivars. Late corrective treatment if necessary. |
|
Oidium |
Topaz |
45 ml |
1 000 l |
|
|
Oidium |
Liquid Sulpher |
1 l |
1 000 l |
Prevention of early leaf fall. |
All the fungicides and/or pesticides named under a specific spray number can be mixed and sprayed together. This programme is a guideline only and it may vary, e.g. three Ronilan sprays may be necessary in some seasons while optimal canopy density may reduce the number of sprays during certain seasons. It is, therefore, necessary to check and clarify the spraying programme at the beginning of each growing season and in this regard Mr. Pieter le Roux of Agronova (Tel. 8626016/7/8) is strongly recommended.
11. FERTILISATION
Young, non-bearing vineyards are fertilised throughout the active growing season at specific intervals. The first application is done about three weeks after budding and then every six weeks until the middle of March when the last quantity is applied. The total recommended quantity of nutrients and/or mixtures must be divided by six to obtain the quantity of fertiliser necessary per application. For bearing vineyards the following approach is recommended: Because of varying soil types on Kleine Uitzicht each block of vineyard will probably demand a unique fertilisation strategy. This strategy can only be based on the analytical results of soil and leaf samples. It is, therefore, strongly recommended that soil samples be taken on the basis which was discussed with Dawid Saayman, Soil scientist, University of Stellenbosch (Tel. 808 4789).
12. KEEPING OF RECORDS
Complete block records are a prerequisite for efficient management. The attached system for keeping of records is only a recommendation and it can be adapted in any way. The system can be computer driven and is given in Addendum B.
13. PROJECTION OF PRODUCTION
The projection of production is given in Table 4 and is based on certain suppositions. These figures are only reachable if vine training, winter pruning, canopy management and crop control is correctly implemented.
TABLE 4. Projection of production of vineyards on Kleine Uitzicht
|
Cultivar |
Surface (ha) |
Yield (t/ha) |
Total production (t) |
Total number of cases |
|
Cabernet Sauv. |
7,5 |
8,0 |
60 |
|
|
Cabernet Franc |
2,5 |
7,0 |
17,5 |
|
|
Merlot |
3,5 |
9,0 |
31,5 |
|
|
Petit Verdot |
1,0 |
10,0 |
10 |
|
|
Malbec |
1,9 |
10,0 |
19 |
|
|
TOTAL |
16,4 |
138 |
10 000 |
14. GENERAL
This planning must be regarded as a guideline. Any adjustment of this guideline is possible and must be reconsidered as experience grows. Success with the implementation of this planning, I sincerely hope that this will contribute towards reaching the goals you have set out to achieve.
E. ARCHER
DEPT. OF VITICULTURE AND OENOLOGY
UNIVERSITY OF STELLENBOSCH