The relationship between leaf area index, light interception and light distribution within apple tree canopies trained to the spindle system, HYTEC, "Solen" and "Mikado" was studied. The type of trees studied were 7-year-old 'Sampion' semi-dwarf apple trees which were grown at a distance of 4 x 1.8 m apart. The highest leaf area index (LAI) and the highest light interception was observed in trees trained on the "Mikado" system. The lowest light interception was in the HYTEC and "Solen" systems. Positive relationships were found between total leaf area per tree, LAI and light interception. Light distribution within a tree canopy was the most beneficial in the "Mikado" system. In the other systems, light penetration to the inner and basal parts of the tree canopy was obstructed. Summer pruning significantly improved light distribution within the tree canopy.