• Soil texture
    crop soil texture
    Nutrient-rich, humic loamy soil, no waterlogging
  • Min. temperature
    crop temperature icon
    Yield losses in late frosts, primarily in bloom
  • pH
    Apple crop pH value
    pH optimal: 5.5-6.5
  • Water demand
    Apple crop rainfall value
    Min. 400-500 l/m2, for yield protection and increase when frequently watered
  • Vernalisation
    Apple crop vernalisation
    -
  • Plant density
    crop density
    Depending on form and type and water supply, For low stem: Distance between the rows: 3.5-4.5m Distance in the row: 1.5-2.0m
  • Seeding Depth
    crop seeding depth
    -
Apple

Commercial apple cultivation has changed dramatically since the 1970s, as it has for most fruit trees. In contrast to the large-canopy, high-stemmed labour intensive trees that were dominant until then, commercial cultivation today uses only the low-stemmed form. Thus,10 to 20 times more trees can be grown in the same area. Their height is limited so that all work can be done by hand without a ladder. Cherries for the processing industry are often harvested mechanically. In the mid-nineteenth century about 2000 varieties of apples were known, while today there are only 20-30 varieties of economic importance.

Key facts
  • change from tall stem to low stem since the 1970s
  • pH value of 5.5-6.5
  • soil fertilization, foliar feeding, fertigation possible
  • CaO fertilization important for quality
General Information
General Information
Nutrient demand
Nutrient demand
Fertilization
Fertilization
APPLE - THE MOST IMPORTANT TREE FRUIT
Apples are usually grown in regions with well-drained, humus-rich soils and areas where late frosts are rare. Sunny locations are ideal, but heat and, above all dryness have a negative effect on fruit formation and quality. The tree form (high-, half- or low-stemmed) is determined by the rootstock. Today, only low-stemmed apples are grown commercially. High-stemmed trees were replaced because low-stemmed trees are easier to work and give earlier yields once established.
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Apples need a lot of calcium
An adequate supply of calcium (Ca) to trees is hugely important for the production of storable apples, although only about 3kg of Ca is stored in the pulp per ha and removed per harvest. Even minor Ca deficiencies lead to unstable cell walls and physiological disorders. Basal fertilization with P, K, Mg, Ca and B is best done during the dormancy period (November - April), on snow-free, not frozen or heavily soaked soil. Organic material is also applied preferably at the beginning of the season (March - April). The quantity is based on the amount extracted from the ground by the harvest.
Extraction quantities for apples

Element

Uptake

(Unit/t of production)

Removal

(Unit/t of production)

Sensitivity to deficiency

N

1.7

0.6

Very Sensitive

P2O5

0.9

0.4

Sensitive

K2O

2.9

2

Very Sensitive

CaO

4.9

0.1

Very Sensitive

MgO

0.9

0.2

Sensitive

TE

Boron (B), if required

The table shows uptake and extraction per tonne of apple yield. According to this, apple trees need mainly nitrogen, potash and calcium. For example, an apple yield of 50t/ha takes up 85kg N/ha. If the soil provides 30kg N/ha, then 55kg N/ha would need to be added as fertilizer. The harvest removes 30kg N/ha from the field.

1. Topsoil fertilization

Granulated fertilizers are applied with the fertilizer spreader. The big advantage of this application technique is a high performance per hectare and the fact that technology is universally available.

2. Fertilization of the tree rows

Best suited for N fertilization in liquid form. Liquid fertilizer is dissolved in the tank and can be applied with herbicide. The nutrients are more targeted to the plants when applied like this.

3. Fertigation

Fertigation is the addition of fertilizer to the irrigation water using suitable equipment. The advantage of fertigation is that the nutrients are applied continuously and in a targeted manner. The increased use of drip irrigation systems in orchards has also increased the importance of fertigation.

4. Foliar feeding

Foliar applications are suitable when deficiencies need to be compensated for as quickly as possible. The roots cannot absorb all the required nutrients at the desired rate (under specific soil or weather conditions). At this time, one or more applications of foliar fertilizer make sense. Nutrients that miss the leaf can also be absorbed from the soil.

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Nitrogen fertilization

Nitrogen fertilization image

Calcium fertilization

Calcium fertilization image

Magnesium

Magnesium image

Nitrogen fertilization

Nitrogen fertilization is carried out in two to three doses once growth has started, shortly before flowering until the end of June. The trees absorb nitrogen mainly as nitrate. Nitrate (anion) can promote the uptake of cations such as calcium (Ca2+), magnesium (Mg2+) and potassium (K+). N doses can be applied in a targeted manner to the tree rows and only occasionally to the tramlines. If the N fertilizer is concentrated at the tree rows only, the concentration (N per area) should not exceed twice the concentration, which would be used at the total area. The total amount can be concentrated on the strip if used together with P, K, and Mg. N fertilization can be done very well in liquid form (herbicide boom sprayer or via irrigation). Young trees are fertilized according to their stage of development.

Calcium fertilization

Calcium is provided as chloride, oxide or chelate to prevent physiological disorders such as bitter pits, flesh browning, soft pulp, etc. Often one to two treatments, five and three weeks before harvest, are sufficient. Susceptible varieties or trees with low fruit setting need four to six treatments, approximately every ten days. Calcium is important for cell wall strength and cell wall growth and thus, for good storage quality and shelf life.

Magnesium

Depending on growth and yield, the annual extraction of MgO is approximately 30kg/ha. The leaves take up two thirds but remain largely in the nutrient cycle. The use of Mg-containing limestone in the course of a preservation liming is favourable.