CANOPY DEVELOPMENT, LIGHT AND SPRAY PENETRATION IN GOLDEN DELICIOUS TREES IN FOUR MANAGEMENT SYSTEMS
The canopy development, light and spray penetration of 'Golden Delicious' apple trees grown in a replicated study of the following management systems was determined: slender spindle (2151 t/ha), trellis (1121 t/ha), interstem hedgerow (795 t/ha), pyramid hedgerow (426 t/ha). Pyramid hedgerow trees had the greatest trunk cross section, height, spread and canopy volume/tree, but had a lower canopy volume/ha than the slender spindle or trellis. Interstem hedgerow trees had the most open canopy with the lowest amount of leaf area/unit of canopy height and leaf area index. Trellis trees had the greatest number of fruit/100 cm2 of area of both spur and shoot leaves and also the highest yield/unit trunk cross-section of the 4 systems. Light values integrated over time in the most dense portion of the canopy were higher in the trellis and inter-stem hedgerow systems than in the slender spindle and pyramid hedgerow systems. Spray penetration measured at the same canopy location as light penetration was hhighest in the trellis followed by slender spindle, interstem hedgerow, and pyramid hedgerow with significant differences between each of the systems. The upper third of the canopy of all systems had the largest numbers of flowers and fruits, greatest amount of fruit/100 cm2 of leaf area and highest amount of sun in both north and south quadrants.
Ferree, D.C. and Hall, F.R. (1981). CANOPY DEVELOPMENT, LIGHT AND SPRAY PENETRATION IN GOLDEN DELICIOUS TREES IN FOUR MANAGEMENT SYSTEMS. Acta Hortic. 114, 91-99