Which cutting methods achieve the best yield

The Oeschbergschnitt - raising a stable high stem crown

by Markus Zehnder, District Office Zollernalbkreis

Controversial discussions about the 'right' pruning of fruit trees have decades of tradition. The upbringing of fruit tree crowns must be based on the principle, both in the youth and in the yield stage, that as far as possible all parts of the crown are exposed evenly. This is especially true for the inner crown parts. Only in evenly exposed crowns can it be guaranteed that the crown expansion is limited both in height and in width and thus the branch structure remains stable over the long term.

As early as 1888, Nicolas Gaucher, director of the fruit and horticultural school and later managing director of the regional fruit growing association, described the upbringing of pyramid crowns in his handbook of fruit cultivation. Its principles were later adopted by Wenk and Winkelmann for the training of tree maintenance and were taught until the 1970s. This method, also known as the “Alt-Württemberger Schnitt”, recommended that a second series of branches be raised on a gap. Today the old fruit tree tops show us that this can lead to overbuilding of the upper parts of the crown and, as a result, to shading and bare of the lower and inner parts of the crown. That is why this form of education has not been taught by the district advisors in Baden-Württemberg for many years. Since the 1950s there have been various approaches to rethink the cut of standard crowns. The Oeschbergschnitt, developed by Hans Spreng, long-time director of the Swiss Center for Fruit Growing in Oeschberg, provided crucial food for thought.

Today, the following principles apply to crown training in orchards:

  1. Raising a slim middle, garnished with short fruit branches and fruit wood, but without a second series of branches.
  2. Raising 3-4 leading branches with a flat angle of departure, but steep leading branch extension.
  3. Development of strong, flat and subordinate fruit branches on the central shoot and leading branches.

These principles can be found predominantly in the Oeschberg section developed by Hans Spreng since the late 1920s, so that today it can serve as a guideline.

Hans Spreng had learned how to cut fruit trees from his father. This in turn was in class with Nicolas Gaucher in Stuttgart. Son Hans wanted to achieve economical table apple production on tall trunks and realized that insurmountable difficulties would arise in the practical application of the Württemberg pruning method (e.g. insufficient exposure of the inner crown areas, tall and labor-intensive trees). Over the course of 30 years, he developed the Oeschberg pattern, a cutting method that met his goals.

The rethinking slowly spread to southern Germany as well. After a professional stay in Oeschberg, Helmut Palmer tried to introduce this pattern as the "Oeschberg-Palmer" pattern in Baden-Württemberg from the 1950s onwards. Since this - also due to his uncompromising demeanor - did not meet the desired open ears of the specialist advisors at the time, the so-called "Württemberg fruit growing war" ensued. But also Dr. P.G. de Haas (then professor at the TH Hannover) published his principles for the "natural fruit tree pruning" for the first time in 1965 and based on the Oeschbergschnitt. The rethinking had now spread widely. The then Ludwigsburg consultant Heiner Schmid published his book "Obstbaumschnitt" for the first time in 1978 by the Eugen Ulmer publishing house, the 9th edition of which is still considered to be groundbreaking today. He, too, moved away from the "Alt-Württemberger Schnitt" and adopted the basic features of the Oeschbergschnitt.
Hans Spreng's aim was to develop an "easily understandable and clear teaching method" that would enable fruit formation in the lower and inner crown areas over the long term. But he also clearly pointed out that no tree pruning should be done according to scheme F: “Anyone who wants to deal with the care of the crown of the fruit trees must not only master the method, but also be a good observer and know the most important basic physiological laws which the life of the trees obeys ”(KOBEL / SPRENG 1949). Recognizing and taking into account fruit-type-specific growth characteristics is crucial here.

Components of an Oeschberg crown are:

  1. The central shoot (trunk extension)
    The central drive builds the crown upwards. With the help of the fruit branches, he ensures that the interior of the crown is garnished with fruit wood. The strong fruit branches raised on the central shoot are intended to take advantage of the gaps between the leading branches. This only works if the leading branches are raised at a flat angle (at least 45 °, better 50 °).
  2. The main branches
    Four main branches are raised at the Oeschbergkrone. However, if a subordinate side branch is raised on each side of the guide branch in a modification of the Oeschberg section to better utilize the crown space, the crown should be formed with 3 guide branches. The leading branches must not be raised in a lively manner, but rather scattered over a good 30 cm on the central shoot. Your departure angle should be 45 to 50 °. Then it is advisable to pull it steeper and steeper until the guide branch extension is almost vertical. This vertical position is a prerequisite for stability and permanent new growth.
  3. The fruit branches
    Stronger branches that are raised are referred to as fruit branches. They carry the fruitwood. The distance between the fruit branches depends on the variety. In the case of slow-growing varieties with short fruit wood (e.g. Goldparmäne, Champagne Renette, Klarapfel), more fruit branches are raised. In terms of strength, they are also subordinate to the leading branches and the central branch.
  4. The fruit wood
    Central shoot, leading branches and fruit branches form the framework of the tree. Fruitwood can and should be raised throughout the crown. It is only thinned, rejuvenated or removed, but not subjected to annual treatment. This is particularly important to counteract irregular fruit formation (alternation). Weak fruitwood is also raised on the top of the branch to shade the branches. To promote fruit wood formation, shoots can be flattened and their end buds removed.

A systematic crown structure is described with the oeschberg section. The crown is divided into the named components. Second or even third series of guidelines are a thing of the past. However, flexibility is required in implementing these guidelines. An attentive arborist should develop the ability to observe the reaction of his pruning on the tree and, if necessary, react to it. The almost Christmas tree-like growth of the Upper Austrian Wine Pear or the arched growth of Alexander Lucas cannot be “forced” into this crown shape. A consistent Oeschberg section would not be "natural" here. As a modification of the principles of the Oeschbergschnitt, there is also the variant that subordinate side branches are raised on the main branches. It should be noted, however, that these are arranged so slim that the crown remains open and accessible. Often it can also be observed that leading branches are raised too flat, tip outwards with the fruit yield and lag behind in development. The only thing that helps here is tightening a new guide branch extension with a steeper position.

In addition to all the advantages of the Oeschberg cut, it must be added that the fruit trees, which are consistently cultivated according to the Oeschberg method, are deprived of the opportunity to form a crown typical of the variety. This does not correspond to a natural crown and leads to a standardized crown appearance. This makes it much more difficult to determine the variety based on the crown pattern.
These statements show that the Oeschbergschnitt does provide a good guideline, but should not be implemented dogmatically in practice, but flexibly and variably.