Choosing rootstocks
Viticultural benefits
Rootstocks can provide viticultural benefits as well as protection against phylloxera, and should be seen as an extra 'tool' that growers can use to help them increase their efficiency and profitability. The main benefits that rootstocks can provide in addition to phylloxera tolerance are:
- Nematode resistance
- Soil salinity (salt) tolerance
- Water use efficiency/drought tolerance
- Increase set
- Increases or decreases in scion vigour
- Advancing fruit maturity
- Lime tolerance
- Soil acidity tolerance
Considerations
There is no single rootstock that can meet the different challenges of every site. Each rootstock has its own particular set of characteristics, strengths and weaknesses. The selection of the most appropriate rootstock for any given situation requires a thorough understanding of the particular site in which the vines are to be planted, as well as knowing the likely product end-use specifications. The following factors can be influenced by choice of an appropriate rootstock (click on each one for information on using rootstock to manage each site factor):
Site Factors
- Nematodes show more ›
- Nematodes are present in most viticultural regions of South Australia. They are commonly found in sandy soils previously planted to grapevines or other horticultural crops. In a survey conducted across 49 vineyards in South Australia it was found that 94% contained at least one and up to five species of nematodes (Quader, Riley, and Walker 2002). The most common and economically important nematode is Root-Knot Nematode (Meliodogyne sp.)
Loss of production due to nematode infestation in Australian viticulture has been estimated at approximately 7% (Stirling et al. 1992) and there can be up to 60% loss in heavily infested vineyards. (Nicol and van Heeswijk, 1997). Symptoms may only be expressed when the vines are placed under environmental stress such as drought or heat. When planting into land previously used for horticultural production or into sandy virgin soils it is important that growers test for the presence of nematodes.
[NB It is also important to remember that nematodes multiply rapidly and even if your test shows that you currently have relatively low population levels, the numbers will increase once your vines are planted and may have an economic impact later in your vineyard's development.]
In nematode-infested soils rootstocks are the most effective management option. Your choice of rootstock needs to take into account the species of nematode present, as rootstock resistance to one species of nematode does not imply resistance to all types (Walker 2002).
Click here for more information on nematodes – include comprehensive information on the relative resistance of a wide range of rootstocks to the different species of nematodes, and details on sampling for nematodes.
This information is reproduced from J.M. Nicol et al (1999) Impact of nematodes on grapevine growth and productivity: current knowledge and future directions, with special reference to Australian viticulture. Australian Journal of Grape and Wine Research 5, 109-127 (with permission from the Australian Society of Viticulture and Oenology).
‹‹ hide - Soil and water salinity show more ›
- The salinity of irrigation water and salinity associated with soils or rising water tables can affect productivity in grapevines and is detrimental to wine quality. Grapevines are considered to be moderately sensitive to salinity, and the use of some rootstocks can reduce the effects of salinity, as Vitis vinifera (own rooted vines) accumulates salt at greater levels than many commonly used rootstocks. The following table is a guide to the salt tolerance of a range of commonly used rootstocks. The values refer to the approximate soil saturation paste salinity level (ds/m) above which yield reductions will occur. The reduction in yield may be as much as 9.6% for every one unit ds/m increase above the threshold (Walker and Stevens, 2004).
Table 1. A guide to the salt tolerance of a range of rootstocks (from Tee et al. 2003)| Classification of salt tolerance | Grapevine | Approximate threshold soil saturation paste salinity (ds/m) | | Sensitive | own roots, 3309C, 1202C, K51-40 | 1.8 | | Moderately Sensitive | 5BB Kober, 5C Teleki, 110 Richter, 99 Richter, K51-32 | 2.5 | | Moderately Tolerant | 140 Ruggeri, Schwarzmann, 101-14, Ramsey | 3.3 | | Tolerant | 1103 Paulsen | 5.6 |
Note: Classification is based on the best available data from Walker et al.
It should be noted that in some recent work at Merbein on the chloride exclusion of rootstocks with long-term saline irrigation it was found that the ability of 1103 Paulsen and Ramsey to exclude salt appeared to be deteriorating. In similar work at Padthaway, however, the same phenomenon was not observed. The study concluded that the rootstocks 140 Ruggeri, Schwarzmann and Rupestris St George have performed the best under long-term saline irrigation at Merbein. (Tregeagle, Walker, Tisdall and Blackmore, 2004).
Measuring Salinity
To find out how to measure salinity in your vineyard Click here.
‹‹ hide - Water availability show more ›
- Some rootstocks are described as having good 'drought tolerance'. In our current grape growing conditions, this can mean a considerable advantage for the grower where water availability is restricted and can mean substantial environmental and economic benefits in terms of improving water-use efficiency.
Characterising the water-use efficiency or drought tolerance of the commonly used rootstocks in Australia is a difficult exercise as there are many complex physiological mechanisms. These mechanisms interact with one another and are also influenced by the soil, environment and cultural practices.
Recent work by Walker et al. (2004) has also shown that the effect of rootstocks on water-use efficiency is scion specific, further complicating matters. Because of these complex interactions the results and conclusions obtained from different studies on the water-use efficiency of different rootstocks are often contradictory. This has made it difficult to definitively rank the commonly used rootstocks from most to least water use efficient or drought tolerant. The classification of rootstocks below is based on the consistencies of their performances in a number of studies from both Australia and overseas.
Group 1. (Highly Tolerant)
Rootstocks that have consistently been found in research to be WUE or drought tolerant.
· Ramsey
· 140 Ruggeri
Group 2. (Tolerant)
Rootstocks that have been found to be WUE/drought tolerant in some studies but not others.
· 1103 Paulsen
· 110 Richter
· 99 Richter
Group 3. (Susceptible)
Rootstock that have never/rarely been found to be WUE or drought tolerant.
· 5C Teleki
· SO4
· 5BB Kober
· 101-14
· Schwarzmann
‹‹ hide - Soil pH (acid and lime soils) show more ›
- Soil Acidity
Rootstocks can be chosen that are able to cope with relatively high acid levels in the soil. (Soil amelioration is still recommended to correct strongly acidic soils and prevent potential aluminium, manganese and copper toxicity, irrespective of the type of rootstock to be used.) The availability of certain nutrients rapidly diminishes as pH decreases below 7.0.
However, it is generally soils below pH 5.5 that can lead to nutrient deficiency (N, P, K, S, Ca and Mg) – or conversely nutrient toxicity in grapevines (Al, Cu and Mn). There are very few areas in South Australia where growth is limited by acidic soils and as a result there has been little local research done on which rootstocks perform the best under such conditions. The only region in South Australia with widespread soil acidity issues is the Adelaide Hills. In Victoria the following rootstocks have been recommended for acid soils:
· 140 Ruggeri,
· 99 Richter and possibly
· Ramsey,
· 110 Richter
· 1202C
The following rootstocks should be avoided:
· Schwarzmann
· 5C Teleki,
· 5BB Kober,
· 5A Teleki and
· 3309C
(Whiting 1991; Buchanan et al. 1992).
The little known rootstock Gravesac has proven tolerance to acid soils. (Delas 1992).
Soil Lime Content
Many vineyards in South Australia are planted on calcareous (appreciable lime content) soils. The pH of calcareous soils is determined by the presence of calcium carbonate (lime). As the soil pH increases above 7.0, the soil becomes more alkaline and certain nutrients become less available. These alkaline soils have the potential to contribute to lime-induced chlorosis, particularly in cold, wet springs. Most rootstocks are far more susceptible to chlorosis than Vitis vinifera; however, the following rootstocks do have a good tolerance to lime:
· 140 Ruggeri
· 110 Richter
· 99 Richter
· 1103 Paulsen
· SO4
· 420A
· 5BB Kober and
· 5C Teleki
The following rootstocks should be avoided in soils with high lime content:
· Schwarzmann
· 101-14
· 3309C
‹‹ hide - Climate and fruit set show more ›
- Rootstocks have been shown to influence fruit set. Improving fruit set is of particular importance in the cool climate regions such as the Adelaide Hills and Coonawarra. The most commonly used rootstock for this purpose in South Australia is 5C Teleki, however, growers have reported improvements with other rootstocks as well. Recent work has shown that the increase in fruit set may be related to the uptake of Molybdenum. Work done by Gridley (2003) with Merlot on own roots, 140 Ruggeri and Schwarzmann, has shown a similar percent fruit set for all three but a lower proportion of shot berries on 140 Ruggeri and Schwarzmann.
The following table classifies rootstocks on their ability to influence fruit set and fruiting for conditions in Oregon (Candolfi-Vasconcelos 1995).
Table 1. Rootstocks and their influence on fruitset.| Improving set and or fertility | Schwarzmann, 3309C, 101-14, 44-53, 420A, 1616C | | Useful for scions suffering poor set | 5C Teleki | | Should not be used where set is doubtful | 110 Richter | | Causing imperfect set in fertile soils | 5BB Kober, 140 Ruggeri, Rupestris St George, 8B Teleki | | Good for cool regions | 99 Richter | | No recommendation | 1103 Paulsen, 161-49, Gravesac. |
From May (2004)
‹‹ hide - Climate and ripening (maturity) show more ›
- Influence of Rootstock on Maturity
Rootstocks can influence fruit maturity – hence ripening date can either be delayed or advanced. The relative length of the growing season varies among the rootstocks and it is considered this may influence time of grape maturity. In addition, rootstocks affect the relative vigour and fruit yield, which also influences maturity date. It may be advantageous to use a rootstock that advances maturity date in a cool climate region to allow the fruit to reach physiological ripeness before the end of the ripening season. The best rootstocks for advancing maturity are:
· 101-14
· Schwarzmann
· 5C Teleki
· 3309C
· 420A
‹‹ hide - Waterlogging show more ›
- Waterlogging
In situations were there is an impermeable layer close to the soil surface and the site experiences high spring rainfall, there may be the potential for waterlogging. Some rootstocks are more tolerant of water-logging than others, but none are better adapted than ungrafted vines. Those that should be considered in situations of potential waterlogging include:
· Schwarzmann
· 110 Richter
· 1103 Paulsen
Those that should be avoided are:
· 99 Richter
· 5BB Kober
· SO4
· 420A
· 101-14
· 140 Ruggeri and
· Ramsey
(Whiting 2003)
‹‹ hide - Site vigour potential show more ›
- Rootstocks have a major affect on vine vigour, and vine vigour has a major effect on final wine quality. A grower must assess the potential vigour of the site, as well as the inherent vigour of the scion variety and the end product yield specifications before choosing an appropriate rootstock.
The potential vigour of a site is influenced by:
· the potential rooting depth of the soil
· soil fertility
· climatic conditions.
The overall site vigour potential will be a combination of these factors.
Potential Rooting Depth of the Soil
In the soil profile the depth to the impenetrable or impermeable layer is important as it determines the volume of soil that the vine roots can explore for moisture and nutrients. In general it can be said that the greater the potential rooting depth, the greater the potential for vigour. When planting on shallow soils (<20cm) a grower should consider using a more vigorous rootstock and when planting on a deep soil (>75cm) a lower vigour rootstock should be considered.
Soil Fertility
The vigour potential of a soil increases with soil fertility. Generally soil fertility increases with increasing soil clay content as clay particles have a greater capacity to store nutrients compared with sand (Gladstones 1992). In fertile soils lower vigour rootstocks should be considered, while in soils lacking in available nutrients a higher vigour rootstock should be considered.
Climate
Warm climates encourage growth so long as moisture is not a limiting factor. Cool to mild climates encourage growth because of the high rainfall that is associated with them. In general a warm, wet climate has greater potential for vigour compared with a cool, wet climate. In the absence of irrigation a cool, wet climate has greater potential for vigour than a warm, dry climate.
‹‹ hide - Scion vigour show more ›
- When choosing an appropriate rootstock for your scion variety it is important to consider:
· the quality objectives
· the inherent vigour of the scion and
· the site vigour potential
Rootstock Cultivar/Scion Variety Vigour
Vine vigour has a major effect on final wine quality and it is well known that the best wine comes from vines that are in balance. Vine vigour is a product of the interactions between the rootstock, soil, scion variety and the climate. Each scion variety and rootstock has different inherent vigour levels:| Variety | Relative Vigour | | Shiraz | High | | Sauvignon Blanc | High | | Chardonnay | Moderate | | Cabernet Sauvignon | Moderate | | Riesling | Moderate | | Merlot | Low |
| Rootstock | Relative Vigour | | Ramsey | High | | 140 Ruggeri | High-moderate | | 1103 Paulsen | High-moderate | | 99 Richter | Moderate-high | | 110 Richter | Moderate-high |
| SO4 | Moderate-high | | 5BB Kober | Moderate-high | | 5C Teleki | Moderate | | Schwarzmann | Low-moderate | | 101-14 | Low-moderate | | 3309C | Low-moderate | | 420A | Low-moderate |
To create a balanced vine, it is generally best to match a high-vigour scion variety with a low to moderate rootstock variety, and vice versa. The site vigour should also be taken into account.
Compatibility
There are a few cases where the scion varieties and rootstock cultivars have been found to be incompatible. In most instances the incompatibility is a result of using virus-infected grafting material (May 1994). The most common incompatibility problems occur when Muscat Gordo Blanco is grafted to Ramsey.
‹‹ hide - End product objectives show more ›
- For commercial grade, higher yield production a high vigour rootstock is more suitable. For low yield, high value wine grape production, lower vigour rootstocks are better suited. However, it is important to note that:
(1) High vigour rootstocks can produce high quality wine grapes as long as they are suitably managed and matched with an appropriate soil type and climate and
(2) Using a low vigour rootstock does not always lead to quality wine grape production.
‹‹ hide
Choosing your rootstock(s)
Download and print-off the 'Rootstock Selection Worksheet' and read the information on each of the relevant considerations listed above to help you identify the potentially suitable rootstocks for your conditions. Alternatively there is an excellent "Rootstock Selector" interactive tool available on the Yalumba Nursery website.
Once you have made your selection, it is helpful to have a thorough understanding of the characteristics of the rootstock(s) you have chosen. See next section.
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