REASONS FOR ADOPTION OF DIFFERENT SYSTEMS IN DIFFERENT COUNTRIES

The systems used for apple and pear growing are remarkably various, even when those still being designed for mechanical pruning and picking are ignored.

In Europe there are many good fruit growers who, after considering the economic returns, still maintain orchards with less than 400 trees/ha, although they would not plant new orchards of this type.

Others prefer semi- intensive systems and plant less than 1000 trees per hectare.

Others only consider HDP, partly with slender spindles, partly with hedgerow systems.

This phenomenon can be explained according to the following analysis of orchard yield and the factors determining it.

Under suitable conditions we can obtain very similar yields from these different systems. Applying a method of yield prediction developed at Bavendorf, we can define the yield capacity of a tree by the surface of its crown-silhouette (c).

For an individual tree this is calculated by multiplying the average crown height (h) by average crown diameter (d):

or for trees with elongated crowns we use the average of the lenghtwise (1) and crosswise (c) diameters

Formula available in full text only

Multiplying this by the number of trees per ha, we get the total crown-silhouette area in m²/ha.

To reach yields between 80 and 100 t/ha of Golden Delicious the orchard must have a total crown-silhouette area of more than 4500 m².