A large percentage of the vineyards in South Africa still develop unevenly during the first year of establishment.

Consequently all the vines cannot be developed on the cordon wires in the same year and the vines have to be pruned back either to “kierie” or two bud stages.

Various growth tubes have appeared on the South African viticultural scene over the past two years. Most of these tubes were initially developed to improve the growth of young trees in the forestry industry. Growth tubes have been used in countries such as the United States (California), Australia and in parts of Europe for many years to promote uniform development of the vine in newly established vineyards from the first year of establishment. Scientific results from abroad have already indicated that the use of these growth tubes not only promotes overall vine development, but also entails large financial advantages for the producer in that the vines come into production at an earlier stage and vineyard management inputs are reduced (reduced irrigation requirements, better weed control in young vineyards, etc.) (Boyer, 1982; Due, 1996; Treeshelters, 1997). Although these growth tubes have been used by South African producers for the past two years, the influence thereof has not been evaluated in a scientific manner for South African conditions.

Three manufacturers/ distributors of growth tubes, namely Treessentials, Tubex and Viticor/ Global Green approached ARC-Nietvoorbij in 1998 to evaluate their respective growth tubes, namely Super Tubes, Tubex and Snapmax. If the growth tubes do indeed entail the advantages that have been proposed, it will be to the producer’s financial advantage because vineyards will not only come into production at an earlier stage, but the economic breakeven point may be reached a year or more sooner. With a plant width of 1m x 2.75m (3 636 vines/ha), at present the initial capital outlay for the purchase of these growth tubes can amount to between R12 726/ha and R10 200/ha, which is relatively high. An advantage of these tubes is, however, that they may be used repeatedly and have a guaranteed life expentancy of 3 to 5 years. At the present cost this means an expense of only R2 545.20/ha or 70 cents/vine. If the production claim of 17.23 t/ha to 22.22 t/ha for Chardonnay may be reached in the second year after establishment (Boyer, 1982), it means that the total cost of the growth tubes will already be recovered in the first two years.

Material and methods

Ten different growth tubes were installed on 8 and 9 October 1998 during budding in a newly established Chardonnay vineyard in Robertson (Photo 1), and just after budding in a Sauvignon blanc vineyard at Nietvoorbij (Photo 2). A control, where no tubes were installed, was also included at each of the sites. The two trials were laid out according to a randomised block design with five repetitions of 10 vines per site. In Robertson irrigation was applied using micro-spitters according to class A pan evaporation figures. The vineyard at Nietvoorbij received three additional irrigations by means of sprinkle irrigation. In Robertson temperature sensors were installed inside and outside the growth tubes to monitor inside and outside temperatures on an hourly basis.

During the evaluation of the tubes the following aspects were monitored:

  • User friendliness during installation, after installation and during the removal of the tubes.
  • Occurrence of pests and diseases and control thereof.
  • Growth tempo (days until the vines reached pencil thickness at the cordon wire and could be topped). Shoot lengths were measured on a weekly basis at both sites to determine the increase in growth and therefore growth tempo.
  • Stem thickness of the rootstock and the scion above the graft and at the cordon wire.

One of the most important requirements during installation and afterwards is that the base of the tubes has to be sealed with soil on the outside to a height of at least 5 cm or sunken to a depth of 5 cm to eliminate air flow from the bottom. The soil at the base of the tube must be compacted by treading on it, in order to seal the tubes properly at the base.

Results and discussion

The results of nine of the growth tubes are reported below. A general overview of the first year’s results is given and no recommendations are made regarding results obtained with specific tubes. A few advantages and disadvantages of the tubes will be discussed.

Advantages of growth tubes
1.Installation is easy and does not take much time. Some of the tubes are sturdier than others and do not have to be folded or stapled.

All tubes already have the required holes and/or clips to attach them to cordon wires or wooden poles, reeds, etc. Here it is important to note that the tubes have to be securely attached to cordon wires or irrigation wires so that they will not move and blow away during strong winds. Some of the tubes are equipped with specially designed snap locks to attach them to the cordon wire and prevent them from moving on the cordon wire (Photo 3).
3.Chemical weed control can be safely practised. Manual labour for grubbing of weeds is eliminated.
4.No labour is required to attach the shoots to the cordon wire.
5.Stems develop straighter than usual (Photo 4).
6.Suckering can take place in all the tubes. Some tubes were better designed for this purpose than others, however, an important tip is not to begin suckering before shoots start to grow higher than the tubes. It is very important that the stems should not be stripped of their leaves. Only the lateral shoots and unnecessary main shoots must be suckered. If all the leaves on the stem are stripped, or suckered too early, the vine’s photosynthetic capacity is reduced, with the result that the mini-hothouse effect of the tubes is neutralised. This also reduces the factory which provides nutrients for root development.

The temperature and humidity inside the tubes are too high for the development of downy mildew and powdery mildew. Spraying against fungal diseases is therefore unnecessary until the shoots start to extend out of the top of the tubes and spraying costs are thus reduced.
8.Standard pest control may be exercised and no special measures or methods are required.
9.Depending on whether lateral shoorts are developed on the cordon wire in the first year, it is relatively easy to remove all the different kinds of tubes and under normal circumstances this does not require a lot of time.
10.Once removed, tubes may be folded flat and take up relatively little storage space.
11.If tubes are cut open at the side, they may be used again the following year by sealing the sides with adhesive tape.
12.All the tubes are re-useable. This distributes the cost of the tubes over the number of years that they will be used.
13.The soil in the tube remained moist longer than that of the control, which means that the period between irrigation can probably also be extended.
14.No plastic is required for the establishment of vines which receive supplementary irrigation.
15.Vines are also protected against animal and wind damage.

Disadvantages of growth tubes
1.Photo 5. Shoots growing out of the folds of the growth tubes because the clips were not properly attached.Some of the tubes first have to be folded or stapled before they can be installed. This may take up to 11 or 12 seconds per tube. When the tubes are stapled, one should ensure that the sides do not overlap too much, otherwise the volume of the tube is reduced and the efficiency of the tube may be restricted. This often results in shoots growing out of the sides of the tubes. This also happens when the tubes are not properly clipped shut or stapled (Photos 5 & 6).
2.Some of the tubes are less sturdy and cannot be pressed into moist soil, which means that the soil has to be ridged against the outside base of the tube. This can be time consuming, since some of the tubes are flimsy and can even collapse in the process.
3.If the right kind of “tube hangers” is not available for some of the tubes, it may create problems to attach the tubes firmly to the cordon wire, especially if an irrigation wire is absent.
4.Where the tubes have folds at the sides, the shoots are sometimes inclined to grow out of the fold and may be damaged at the time of chemical weed control.
5.If lateral shoots are developed on the cordon wire, some of the tubes have to be cut open so that the vines may be suckered or the tubes may have to be removed. These tubes do have a perforated strip at the side which was designed for this purpose.
6.Photo 6. An example of tubes that were installed in such a way that the sides opened up slightly.Snapping the tubes open and shut or removing them during suckering may be time consuming.
7.The design of all the tubes is not quite suitable for the development of lateral shoots on the cordon wires, in which case it is recommended that the tubes should be installed slightly lower than or under the height of the cordon wire.
8.The tubes offer an ideal hideaway for insects.
9.Some of the tubes lose their colour in the first year and therefore possibly also their effectiveness in the following year.
10.The solid tubes may take up a lot of storage space if they are not cut open.
11.The cost should be weighed up against the durability of the tube.

Vineyard performance

Growth tempo was monitored on a weekly basis and the main shoot was topped at cordon wire height as soon as it reached pencil thickness. The first suckering took place at the beginning of December 1998, when most shoots started growing out of the top of the tubes. This was followed by a late suckering at the beginning of February 1999.

Table 1. The influence of growth tubes on the average shoot length of Chardonnay and Sauvignon blanc as measured during the topping of vines at pencil thickness.

Growth tube Average shoot length (cm) *
Nietvoorbij Robertson
Tubex – A 113.2 ab 122.2 abc
Tubex. B 109.9 abc 128.6 a
Tubex. C 107.4 abcd 116.2 bc
Tubex. D 113.2 ab 123.1 abc
Tubex. E 115.1 a 123.7 ab
Super Tubes. 900mm 106.2 abcd 121.8 abc
Super Tubes. 650mm 98.9 de 115.4 bc
Snapmax. White – ** 113.3 c
Snapmax. Green 101.1 dc 116.0 bc
Control 104.3 bcd 118.7 abc

* Values followed by the same letter do not differ significantly. (P>0.05).
** This tube was not evaluated at Nietvoorbij.

All the growth tubes improved the growth rate, making the vines grow faster (Fig. 1 & 2 ). The effect was more prominent in the warmer Robertson area where the shoot length increased to approximately three times the tempo of the control. In general it seems that some of the tubes caused the vines to develop faster than others, but when considering the number of days taken by the vines to reach topping thickness, it is clear that the shoot thickness of the vines did not develop at the same tempo and the difference between vines in the tubes (tube vines) and the control vines was not so prominent (Fig. 3 & 4 ). At Nietvoorbij some of the tube vines reached topping thickness up to 24 days before the control and in Robertson up to 44 days earlier. Although the difference in performance between individual growth tubes in Robertson was significant, on average none of the manufacturers’ tubes performed better than the others.

Table 1 shows the average shoot length at which the various tubes’ shoots reached topping thickness. Although there were a number of significant differences, the information on its own is not worth much. The average number of days the vines took to reach topping thickness indicates that the tempo of shoot thickening does not differ between vines.

Table 2. Damage noted on Sauvignon blanc (Nietvoorbij) and Chardonnay (Robertson) vines that developed in growth tubes.

Type of tube Vines damaged by heat (%) Growing tips that grow downwards (%) Growing tips that broke off once the shoots grew taller than the tubes (%)
Nietvoorbij Robertson Nietvoorbij Robertson Nietvoorbij Robertson

  • Print
  • Email
Wynboer / June 2000
June 2000

Wynboer – Vineyard

Growth Tubes for Establishment of Vineyards

Written by Danie van Schalkwyk

A large percentage of the vineyards in South Africa still develop unevenly during the first year of establishment.

Consequently all the vines cannot be developed on the cordon wires in the same year and the vines have to be pruned back either to “kierie” or two bud stages.

Various growth tubes have appeared on the South African viticultural scene over the past two years. Most of these tubes were initially developed to improve the growth of young trees in the forestry industry. Growth tubes have been used in countries such as the United States (California), Australia and in parts of Europe for many years to promote uniform development of the vine in newly established vineyards from the first year of establishment. Scientific results from abroad have already indicated that the use of these growth tubes not only promotes overall vine development, but also entails large financial advantages for the producer in that the vines come into production at an earlier stage and vineyard management inputs are reduced (reduced irrigation requirements, better weed control in young vineyards, etc.) (Boyer, 1982; Due, 1996; Treeshelters, 1997). Although these growth tubes have been used by South African producers for the past two years, the influence thereof has not been evaluated in a scientific manner for South African conditions.

Photo 1 : Growth tubes at the Chardonnay site in Robertson (1998/99)Three manufacturers/ distributors of growth tubes, namely Treessentials, Tubex and Viticor/ Global Green approached ARC-Nietvoorbij in 1998 to evaluate their respective growth tubes, namely Super Tubes, Tubex and Snapmax. If the growth tubes do indeed entail the advantages that have been proposed, it will be to the producer’s financial advantage because vineyards will not only come into production at an earlier stage, but the economic breakeven point may be reached a year or more sooner. With a plant width of 1m x 2.75m (3 636 vines/ha), at present the initial capital outlay for the purchase of these growth tubes can amount to between R12 726/ha and R10 200/ha, which is relatively high. An advantage of these tubes is, however, that they may be used repeatedly and have a guaranteed life expentancy of 3 to 5 years. At the present cost this means an expense of only R2 545.20/ha or 70 cents/vine. If the production claim of 17.23 t/ha to 22.22 t/ha for Chardonnay may be reached in the second year after establishment (Boyer, 1982), it means that the total cost of the growth tubes will already be recovered in the first two years.

Material and methods

Ten different growth tubes were installed on 8 and 9 October 1998 during budding in a newly established Chardonnay vineyard in Robertson (Photo 1), and just after budding in a Sauvignon blanc vineyard at Nietvoorbij (Photo 2). A control, where no tubes were installed, was also included at each of the sites. The two trials were laid out according to a randomised block design with five repetitions of 10 vines per site. In Robertson irrigation was applied using micro-spitters according to class A pan evaporation figures. The vineyard at Nietvoorbij received three additional irrigations by means of sprinkle irrigation. In Robertson temperature sensors were installed inside and outside the growth tubes to monitor inside and outside temperatures on an hourly basis.

During the evaluation of the tubes the following aspects were monitored:

  • Photo 2. Growth tubes at the Sauvignon blanc site at Nietvoorbij, Stellenbosch (1998/99)User friendliness during installation, after installation and during the removal of the tubes.
  • Occurrence of pests and diseases and control thereof.
  • Growth tempo (days until the vines reached pencil thickness at the cordon wire and could be topped). Shoot lengths were measured on a weekly basis at both sites to determine the increase in growth and therefore growth tempo.
  • Stem thickness of the rootstock and the scion above the graft and at the cordon wire.

One of the most important requirements during installation and afterwards is that the base of the tubes has to be sealed with soil on the outside to a height of at least 5 cm or sunken to a depth of 5 cm to eliminate air flow from the bottom. The soil at the base of the tube must be compacted by treading on it, in order to seal the tubes properly at the base.

Results and discussion

The results of nine of the growth tubes are reported below. A general overview of the first year’s results is given and no recommendations are made regarding results obtained with specific tubes. A few advantages and disadvantages of the tubes will be discussed.

Advantages of growth tubes

  1. Installation is easy and does not take much time. Some of the tubes are sturdier than others and do not have to be folded or stapled.
  2. Photo 3. Tubes with specially designed clips to attach them to the cordon wireAll tubes already have the required holes and/or clips to attach them to cordon wires or wooden poles, reeds, etc. Here it is important to note that the tubes have to be securely attached to cordon wires or irrigation wires so that they will not move and blow away during strong winds. Some of the tubes are equipped with specially designed snap locks to attach them to the cordon wire and prevent them from moving on the cordon wire (Photo 3).
  3. Chemical weed control can be safely practised. Manual labour for grubbing of weeds is eliminated.
  4. No labour is required to attach the shoots to the cordon wire.
  5. Stems develop straighter than usual (Photo 4).
  6. Suckering can take place in all the tubes. Some tubes were better designed for this purpose than others, however, an important tip is not to begin suckering before shoots start to grow higher than the tubes. It is very important that the stems should not be stripped of their leaves. Only the lateral shoots and unnecessary main shoots must be suckered. If all the leaves on the stem are stripped, or suckered too early, the vine’s photosynthetic capacity is reduced, with the result that the mini-hothouse effect of the tubes is neutralised. This also reduces the factory which provides nutrients for root development.
  7. Photo 4. An example of how straight the stems develop in the growth tubes.The temperature and humidity inside the tubes are too high for the development of downy mildew and powdery mildew. Spraying against fungal diseases is therefore unnecessary until the shoots start to extend out of the top of the tubes and spraying costs are thus reduced.
  8. Standard pest control may be exercised and no special measures or methods are required.
  9. Depending on whether lateral shoorts are developed on the cordon wire in the first year, it is relatively easy to remove all the different kinds of tubes and under normal circumstances this does not require a lot of time.
  10. Once removed, tubes may be folded flat and take up relatively little storage space.
  11. If tubes are cut open at the side, they may be used again the following year by sealing the sides with adhesive tape.
  12. All the tubes are re-useable. This distributes the cost of the tubes over the number of years that they will be used.
  13. The soil in the tube remained moist longer than that of the control, which means that the period between irrigation can probably also be extended.
  14. No plastic is required for the establishment of vines which receive supplementary irrigation.
  15. Vines are also protected against animal and wind damage.

Disadvantages of growth tubes

  1. Photo 5. Shoots growing out of the folds of the growth tubes because the clips were not properly attached.Some of the tubes first have to be folded or stapled before they can be installed. This may take up to 11 or 12 seconds per tube. When the tubes are stapled, one should ensure that the sides do not overlap too much, otherwise the volume of the tube is reduced and the efficiency of the tube may be restricted. This often results in shoots growing out of the sides of the tubes. This also happens when the tubes are not properly clipped shut or stapled (Photos 5 & 6).
  2. Some of the tubes are less sturdy and cannot be pressed into moist soil, which means that the soil has to be ridged against the outside base of the tube. This can be time consuming, since some of the tubes are flimsy and can even collapse in the process.
  3. If the right kind of “tube hangers” is not available for some of the tubes, it may create problems to attach the tubes firmly to the cordon wire, especially if an irrigation wire is absent.
  4. Where the tubes have folds at the sides, the shoots are sometimes inclined to grow out of the fold and may be damaged at the time of chemical weed control.
  5. If lateral shoots are developed on the cordon wire, some of the tubes have to be cut open so that the vines may be suckered or the tubes may have to be removed. These tubes do have a perforated strip at the side which was designed for this purpose.
  6. Photo 6. An example of tubes that were installed in such a way that the sides opened up slightly.Snapping the tubes open and shut or removing them during suckering may be time consuming.
  7. The design of all the tubes is not quite suitable for the development of lateral shoots on the cordon wires, in which case it is recommended that the tubes should be installed slightly lower than or under the height of the cordon wire.
  8. The tubes offer an ideal hideaway for insects.
  9. Some of the tubes lose their colour in the first year and therefore possibly also their effectiveness in the following year.
  10. The solid tubes may take up a lot of storage space if they are not cut open.
  11. The cost should be weighed up against the durability of the tube.

Vineyard performance

Growth tempo was monitored on a weekly basis and the main shoot was topped at cordon wire height as soon as it reached pencil thickness. The first suckering took place at the beginning of December 1998, when most shoots started growing out of the top of the tubes. This was followed by a late suckering at the beginning of February 1999.

Table 1. The influence of growth tubes on the average shoot length of Chardonnay and Sauvignon blanc as measured during the topping of vines at pencil thickness.

Growth tube Average shoot length (cm) *
Nietvoorbij Robertson
Tubex – A 113.2 ab 122.2 abc
Tubex. B 109.9 abc 128.6 a
Tubex. C 107.4 abcd 116.2 bc
Tubex. D 113.2 ab 123.1 abc
Tubex. E 115.1 a 123.7 ab
Super Tubes. 900mm 106.2 abcd 121.8 abc
Super Tubes. 650mm 98.9 de 115.4 bc
Snapmax. White – ** 113.3 c
Snapmax. Green 101.1 dc 116.0 bc
Control 104.3 bcd 118.7 abc

* Values followed by the same letter do not differ significantly. (P>0.05).
** This tube was not evaluated at Nietvoorbij.

All the growth tubes improved the growth rate, making the vines grow faster (Fig. 1 & 2 ). The effect was more prominent in the warmer Robertson area where the shoot length increased to approximately three times the tempo of the control. In general it seems that some of the tubes caused the vines to develop faster than others, but when considering the number of days taken by the vines to reach topping thickness, it is clear that the shoot thickness of the vines did not develop at the same tempo and the difference between vines in the tubes (tube vines) and the control vines was not so prominent (Fig. 3 & 4 ). At Nietvoorbij some of the tube vines reached topping thickness up to 24 days before the control and in Robertson up to 44 days earlier. Although the difference in performance between individual growth tubes in Robertson was significant, on average none of the manufacturers’ tubes performed better than the others.

Table 1 shows the average shoot length at which the various tubes’ shoots reached topping thickness. Although there were a number of significant differences, the information on its own is not worth much. The average number of days the vines took to reach topping thickness indicates that the tempo of shoot thickening does not differ between vines.

Table 2. Damage noted on Sauvignon blanc (Nietvoorbij) and Chardonnay (Robertson) vines that developed in growth tubes.

Type of tube Vines damaged by heat (%) Growing tips that grow downwards (%) Growing tips that broke off once the shoots grew taller than the tubes (%)
Nietvoorbij Robertson Nietvoorbij Robertson Nietvoorbij Robertson
Tubex. A

0

0

5

0

0

0

Tubex. B

2.5

0

2.5

0

2.5

0

Tubex – C

0

0

2.5

0

<p align=”

You may like to read these:

Go Back
Shares