Yield, Fruit Quality and Mechanization of the Tall Spindle Apple Production System

The Tall Spindle apple-planting system utilizes highly feathered nursery trees planted at a density of 2,500-3,300 trees/ha. The trees are pruned minimally after planting but feathers are tied below horizontal soon after planting. The tree is grown rapidly to 3.3 m tall with no heading of the leader and little pruning for the first 4-5 years after which tree height is limited each year to 3.3 m by cutting to a side branch. The mature tree is pruned using limb renewal pruning by removing 2-3 of the largest limbs (>2 cm diameter) in the canopy each year by cutting them back to a 2-3 cm long stub. Our trials indicate that the Tall Spindle system is more profitable than either higher or lower density systems. Early yield of recent trials has exceeded 150 t/ha over the first 5 years. Initial planting and tree training costs have been higher than lower density systems but mature pruning costs have been lower than lower density systems. Partial mechanization of dormant pruning by using labor positioning platforms has increased dormant pruning labor productivity by 25-40%. Mechanized side wall shearing of the tree canopy in the summer with a cutter bar has resulted in minimal effect on yield, fruit quality or tree regrowth response in mature Tall Spindle trees.