PEACH YIELD EFFICIENCY AS RELATED TO TREE SHAPE

The yield efficiency of cv Loadel cling peach trees Damas 1869 was evaluated by comparing different training systems at medium density, eight years after planting.

The parameters such as canopy volume, leaf number, surface and distribution, fruit number, weight and distribution (divided into ¼ m³ grids), and light interpection were observed to be interdependent. Depending on training shape, these parameters had widely differing effects at equal crop per tree and per ground area.

The most extended canopies (i.e. "delayed vase") were generally found to be the least efficient nevertheless they utilized more than 20 leaves per fruit.

In the flat and least expansive canopies (i.e. "early palmette") fruit density was observed to increase noticeably, with an availability of only 15–21 leaves per fruit. However, when such apparent high-leaf efficiency was matched by an elevated leaf area index (LAI = 8), fruit size was negatively affected.

The expanded round canopies (i.e. "free central leader" and "delayed vase"), with a low incidence of unproductive zones and a covered ground surface from 65 to 80%, were generally found to perform better than "palmette shape" which covers only 50–60% of ground surface.

On the whole, yield efficiency was highest in "early palmette" shaped trees which had also the least expanded canopy, but the round single shaped trees (i.e. "central leader" and "low delayed vase"), thanks to the good foliage density distribution and light interception, showed better fruit quality.