Canopy Development and Yield Efficiency of ‘Golden Delicious’ Apple Trees in Four Orchard Management Systems1

Abstract

Abstract The canopy development and yield efficiency of ‘Golden Delicious’ apple trees (Malus domestica Borkh.) were measured during the sixth growing season for slender spindle (2151 trees/ha), trellis (1121 trees/ha), interstem hedgerow (795 trees/ha), and pyramid hedgerow (425 tree/ha) management systems. Pyramid hedgerow trees had the greatest trunk circumference, height, spread, and canopy volume/tree, but had a lower canopy volume/ha than the slender spindle or trellis. About 20% of the canopy of all 4 systems was present at bloom in May, 90% in June, and the maximum in July. Spur leaves followed the development pattern of the whole canopy but shoot leaf area did not reach its maximum until August. Interstem hedgerow trees had the most open canopy with the lowest amount of leaf area/unit of canopy height and the greatest amount of light penetration in the canopy. The pyramid hedgerow had a higher LAI than other systems and the increase in light in the upper third of the tree was not as great as the other systems. Trellis trees had the greatest number of fruit/100 cm2 area of both spur and shoot leaves and also the highest yield/unit trunk cross section of the 4 systems. The upper third of the canopy of all systems had the largest number of flowers and fruit, greatest amount of fruit/100 cm2 of leaf area and more light than the mid- and lower-thirds. Cumulative yield/ha and canopy volume/ha were closely related to number of trees/ha but the trellis and interstem system had a greater density of fruit/m2 of canopy than the slender spindle or pyramid hedgerow systems.