If apple orchards are to prove profitable it is important that they begin cropping as soon as possible after planting (i.e. exhibit good yield precocity) and then rapidly build up cropping to high and consistent yield efficiencies in the succeeding years.
The yields in the first few years of the orchard’s life are vital if the investment is to prove viable. Investment appraisals using techniques of Discounted Cash Flows or Net Present Values highlight the importance of yields achieved in the first five years of an orchard’s life.
To achieve these yields in the first few years following planting it is essential that the trees produce adequate numbers of flowers and that these flowers are of sufficient quality to set and retain fruits through until harvest. This precocious cropping must not, however, be at the expense of the trees continuing to grow and fill their allotted space within the orchard. Balanced growth and cropping should be the aim in these early years following planting, as much as in the subsequent years.
When planning and planting young trees the importance and influence of the following should be considered:
- Well-feathered trees
- Choice of rootstock and/or interstock
- Tree age/size and transplanting check
- Soil and foliar nutrition
- Pruning and training techniques
- Plant growth regulator treatments
The importance of planting well-feathered trees
Plant well-feathered trees with healthy, non-desiccated roots. Tree quality at the time of planting has a significant influence on how well the young trees establish and how quickly they begin to flower and fruit.
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| A well feathered two-year old apple tree |
The onset of flowering is advanced and the abundance and quality of flowers improved if well-feathered trees are planted in good fertile soils.
Trees with 6 to 8 strong well-spaced feathers with wide branch angles should be chosen.
It is also important that these relatively large trees receive good water, nutrition and soil management to minimise the transplanting check to growth. Excessive transplanting check to growth will cause tree stunting and may lead to the production of branches with bare wood.
- Various nursery techniques are used to improve tree quality
- Where available choose trees guaranteed virus-free and true-to-type: Healthy trees establish more quickly and crop more abundantly.
- Choose the most appropriate rootstock for the site/soil conditions, the chosen scion variety and the planned system of management: Irrespective of the vigour of tree desired by the apple grower, always choose the rootstock, or rootstock/interstock combination, which is likely to induce precocious cropping. Most dwarfing rootstocks (M.9 and its clones e.g. Pajam 1 and Pajam 2, M.27, P.22 etc.) improve precocity of cropping. Unless soil conditions are excellent avoid use of very dwarfing rootstocks such as M.27 and P.22. Amongst the more vigorous rootstocks MM.106 and M.116 both induce good floral precocity in scions and are well suited to use in cider orchards. Use of dwarfing rootstocks as interstocks also improves floral precocity of scions.
Post planting management
Trees planted in the autumn into deep, highly fertile soils with adequate supplies of water throughout the subsequent season should establish very well and make abundant shoot growth. When planting small or poorly feathered trees this response is desirable. However, where larger than average trees are planted, such conditions could result in excessive shoot growth and the production of fewer, poorer quality flowers in the second season following planting. Tree management after planting should aim to achieve balanced growth and precocious cropping.
Take steps to improve flower quality (i.e. ability to set fruits) on young trees. By being aware of the limitations on fruit set associated with poor flower quality on very young trees, it is possible to improve the situation by:
- Applying appropriate fertilisers, as determined by soil and leaf analysis, preferably through a fertigation system.
- Bending branches down on upright varieties, or varieties with poor fruiting habit, can improve flower quality and subsequent fruit set. This is not necessary in very precocious varieties.
Ensure good tree establishment and avoid bare wood developing by:
- Planting in good conditions, preferably before Christmas. Delayed planting can result in a planting check which is generally undesirable although in some circumstances may be beneficial e.g. stringfellowing.
- Providing adequate water and nutrients (both to the roots and by foliar feeding).
Growers should obtain analyses of the soil mineral and organic matter contents prior to tree planting. Based on these analyses and the current recommendations concerning optimum levels (RB209) any necessary base dressings should be applied.
Supplementary nutrition of trees in their first or second years following planting have been shown to improve crop levels in intensive plantings of 2000+ trees per hectare.
Supplementary irrigation should be applied, preferably using trickle systems, when soil moisture deficits reach 50 mm.
Prevent stress to the trees (e.g. wind desiccation).
Prune and train trees so as to establish ideal balance of growth and flowering:
- Remove excess feathers, especially those with strong upright growth and poor branch angles. This will help produce better leaf and flower quality on the remainder. Aim for 6-8 good feathers. Remove low and unwanted feathers
- Do not tip the leader except when poor quality trees with very weak or few feathers are used. Where good, well feathered trees are planted, leaving the leader unpruned will encourage the development of weak fruiting laterals and give natural growth control of the leader which is ideal in intensive orchards.
- Tie down lateral growth towards the horizontal or below this angle on very strongly growing varieties.
Use low doses of chemical growth regulators where necessary to achieve reduced shoot growth, improved balance of growth and improved fruit set.
- Low concentration treatments with Cultar may aid flower production on young trees that are growing too vigorously.