Orchard Establishment Planning the Orchard The Planting System Planting System Components 
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The planting system is the integration of tree arrangement, planting density, support systems and training schemes. There is no one planting system to suit all situations. Factors such as climate, soil, variety, rootstock, quality of nursery trees, management regimes and economic conditions will determine the optimal combination for each orchard. Essentially fruit production is highly dependant on light interception and distribution in the canopy. A well planned orchard should intercept 70-80% sunlight falling on the land. This means that the planting system needs to have a combination of components that ensures optimal light interception and distribution from an early stage. Tree ArrangementThe goal of tree arrangement is to maximise the efficiency of production by balancing the interception of sunlight with the efficiency of operation (Hoying and Robinson 2006). Trees can be arranged in various ways ranging from single rows through to multiple row or bed systems with occasional drive alleys. The most common tree arrangements for intensive pear production systems are in single or double rows (eg. Open Tatura Trellis).
Figure 1 & 2: Pear trees arranged as a single row (left) and double row in an Open Tatura Trellis system (right) Planting DensityTree density is one of the most important factors that influences the production of fruit in an orchard - particularly in its early years. Many studies with various varieties and rootstocks have shown that increasing tree densities will result in earlier production of pears and increased yields. This is because higher tree densities result in a closed canopy and higher light interception earlier in the life of the orchard when compared with low densities (Kappel and Brownlee 2001, Balkhoven-Baart et al. 2000). The relationship between yield and density does not remain linear however. Whilst cumulative yields can double in going from low to high density plantings, the move to very high and ultra high density results in a less significant increase in yields. Often these increases do not justify the additional costs of establishment. Balkhoven-Baart et al. (2000) demonstrated this in apples where moving from 6000 trees/ha to 10000 trees/ha gave an increase in fruit production of 15%. This is compared to the 40% increase from 3000 trees/ha to 6000 trees/ha. The classification of what constitutes a high density orchard varies between production regions. For the purpose of this site densities are defined as follows;
Figure 3: Very high density 'Conference' pear orchard in the Netherlands (9000 trees/ha) What is the optimum tree density?There are a number of factors that will determine the optimal tree density for an intensive pear orchard. Fundamentally within row spacing (and therefore tree density) needs to be calculated based on the vigour of the scion variety and rootstock and the soil quality. Where the combination of rootstock x scion variety x soil results in vigorous growth it is best to look at wider spacings and therefore lower densities. Where there is access to more dwarfing rootstocks (such as Quince C) planting distances can be reduced (increasing tree density). The decision about planting density is also largely dependant on economic considerations such as establishment costs and likely returns. Whilst it is recognised that higher planting densities will result in earlier and higher yields, many pear production regions are settling on densities of around 2500-4000 trees/ha as the most suitable both production and cost wise. Calculating spacing and densityThe tables below provide a ready guide to planted tree densities at different tree and row widths based on different training systems used for pears. Please note these numbers are based on a planted hectare, no allowance has been made for headlands. The row widths for the Double Row systems is based on row centre to row centre and therefore is accurate irrespective of actual gap between the 2 rows that form each double row.
If you wish to calculate tree numbers per planted hectare for your own spacings the following formulas can be used.
Example = 10000 = 10000 = 1441 trees/planted hectare Table 1: Density and spacing for single row high density/trellis systems Between Tree Spacing (m)
Table 2: Density and spacing for double row systems (eg. Open Tatura Trellis) Between Tree Spacing (m)
Table 3: Density and spacing for Y shaped systems (eg. Traditional Tatura Trellis) Between Tree Spacing (m)
(Source: Paul James, Rural Solutions, SA) Support SystemsSupport or trellis systems are required in most intensive production systems to support the crop load. Often trees in intensive production systems are producing fruit well before the tree's own support system is strong enough to hold the crop. The choice of support system will be influenced by the density and training systems chosen and the availability of materials. It is easier to install an adequate support system at the beginning of an orchard than to replace or repair an inadequate system that fails when trees begin to bear significantly. Tree TrainingThe primary objective of pear tree training is to direct tree growth and develop a strong tree framework that will support quality fruit production. In particular, proper training of pear trees opens up the canopy to ensure maximum light interception and distribution and therefore quality yields. Tree training is particularly important in mature orchards where canopy shape affects the light distribution within the tree canopy. If the intercepted light is not evenly distributed throughout the tree canopy, shading can occur. This can inhibit flower bud development, fruit set and fruit colour. It is important that trees are trained and managed so that they allow for maximum light interception and distribution throughout the canopy, and reduce the risk of heavy internal shading. What is the best training system?Around the world pears are trained in a variety of systems over a range of densities. Whilst many systems are technically sound, it is often a question of costs, management requirements and fruit returns which influence whether a system is actually the most viable option for an orchard. Training systems need to be able to accommodate
Often there can be confusion about the definitions of training systems, particularly between those that appear to apply the same pruning concepts and methods. Generally tree training systems for intensive pear production can be categorised as
Examples of these training systems are provided in the Planting System Examples page. Further InformationThese sites may be useful for growers. However they are intended as an information source only. Any specific chemical or other control recommendations may be outdated or irrelevant for Australian conditions and growers should seek local advice. Please note: By electing to visit sites linked from this page you are leaving the intensivepear.com website International ResourcesIntensive Pear Orchard System Development
ReferencesBalkhoven-Baart, J.M.T., Wagenmakers, P.S., Bootsma, J.H., Groot, M.J. and Wertheim, S.J. (1998). "Developments in Dutch apple plantings." Acta horticulturae 513: 261-270 Hoying S.A., Robinson T.L. (2006).“The apple orchard planting systems puzzle.” Acta Horticulturae 513: 257-260. Kappel F., Brownlee, R. (2001). "Early performance of 'Conference' pear on four training systems." Hortscience 36: 69-71 |
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