The Forms, or shapes, of most fruit trees can be manipulated by pruning and training in order to increase yield. Tree shaping can improve their suitability for different situations and conditions. Pruning a tree to a pyramid shape means that trees can be planted closer together. An open bowl or cup form increases the penetration of sunlight, thus encouraging a high fruit yield whilst keeping the tree short and easy to pick from. Other shapes such as cordons, espaliers and fans offer opportunities for growing trees two dimensionally against walls or fences, or can themselves be trained as barriers.
Bush trees are the traditional open goblet shaped form, with a clear lower stem. Within this branch, several subforms are frequently used; these include the spindlebush-form; which was designed for dense orchards by Schnitz-Hubsh and Heinrichs in Germany in 1936, and is currently also the most popular training system for dwarf apple and pear trees.
Cordons are single stemmed trees with fruiting spurs planted at an angle. Any side branches are removed by pruning. cordons take less space and crop earlier than most other forms which means that more varieties can be got into a small space, but yields are smaller per tree.  A special cordon set-up is the Bouché-Thomas system.
Espaliers have a central vertical trunk with three or four horizontal branches each side. A special espalier in this group is the LePage-system.
Fans have a short central trunk with several radiating branches growing from the crown.
Step-over espaliers have single horizontal branches at 30 cm from the ground and make a novel and productive border to the vegetable plot.
All of these shapes require training by tying the branches to the required form, and pruning to retain the desired structure. This is usually carried out in autumn for major cutting back and late summer for light trimming. Autumn pruning encourages woody growth whilst late summer pruning encourages fruiting. Not all trees will accept all of the shapes above- apples and pears do well as cordons and espaliers for example, whereas cherries prefer to be fanned.
A study on orchard mango trees, in Nelspruit, South Africa, compared open vase, closed vase, central leader, palmette and standard pruning systems, and recommends a modified pyramid, somewhere between a central leader and a closed vase system, for higher density mango orchards. The study also evaluated both post fruit-set and post-harvest pruning, indicating that late mango cultivars benefit from pruning while bearing in late fall, while early cultivars may be best pruned immediately after harvest.
Yield and spacing
Yields and spacing table
Apples and pears
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