The optimization of orchard planting density is regarded as a key factor for successful orchard management. This requires an optimal combination of natural, technical and financial resources. Besides fruit yield, quality factors like the proportion of top colour and fruit size are regarded as decisive economic factors. Fruit yields are finite and cannot be ever increased through higher planting densities. Increased tree density by 3.54 times of two Spindle systems increased fruit yield only by a factor of 1.29. Therefore the optimum planting density has to be found. Higher planting densities are able to achieve higher yields during their first years. Rootstocks, dwarfer than M.9, like P.16 and P.22 are able to increase yield efficiency by 5 to 8% but lose total production by up to 30% on a hectare basis. Therefore in practice it is recommended to increase tree density by 10% in order to balance out the loss of production. The development of plant density on an area of 3,450 ha in the Bodensee area between 1990 and 1998 showed an increase of plant density from 2,600 to 3,600 trees/ha. The economic success of an apple orchard depends to the greatest extent on the price obtained for the fruit. Then the price of trees from the nursery, lower cost of picking and less management hours for maintaining the system. Row distances less than 3 in tend to be too narrow for high picking outputs and easy management. Negative influences on fruit size, colour and soluble solids are only expected in ultra high density plantings above 8,000 trees/ha. An increase in tree density up to 6,400 trees/ha showed a financial benefit in comparison to lower density systems. In leaf 5 the Super Spindle orchard achieved break even through rapidly increasing yields due to a higher tree density per hectare. The Slender Spindle orchard achieved break even one year later in leaf 6. Putting all decisive factors together, the optimum tree density for the Bodensee region is about 4,000 trees/ha.
