Costs of Establishing High Density 

 Apple Plantings 



Wesley R. Autio 



Department of Plant & Soil Science, University of Massachusetts 



In the 1989 New England Apple Survey [Fruit 

 Notes 54(4):12-17] growers stated that 62% of the 

 apple acreage to be planted in 1990-94 would be on 

 dwarfing rootstocks. This figure is a dramatic 

 change from the 15% reported for 1985-89, showing 

 that the industry is moving to more intensive man- 

 agement systems which may be more economically 

 sound [Fruit Notes 53(l):4-7], easier to prune and 

 harvest, and use less spray material (because of the 

 reduction of spray material required per acre). 

 However, growing an apple tree on a dwarfing root- 

 stock is not the same as growing one on a free- 

 standing, semi-dwarf or standard rootstock. Grow- 

 ers must be aware of the different level of expertise 

 and inputs required. A previous Fruit Notes 

 [54(4):6-10] article described some of the horticul- 

 tural techniques required to manage intensive sys- 

 tems; however, before choosing a system it is critical 

 to know something about the cost of establishing and 

 maintaining it. 



To become more familiar with the peculiarities of 

 these systems and to obtain accurate data on costs, 

 I established a trial of four training systems at the 

 University of Massachusetts Horticultural Re- 

 search Center (Belchertown) in the spring of 1990. 

 This trial includes Nicobel Jonagold/M.9 trained as 

 a small central leader, as a slender spindle, as a 

 vertical axis, and on 4-wire, vertical trellis. These 

 systems were established with the monetary sup- 

 port of the Massachusetts Fruit Growers' Associa- 

 tion and a University of Massachusetts alumni 

 donation. In this article I will detail the establish- 

 ment costs of each system, and in future articles I 

 will discuss management problems and costs as the 

 trees develop. Anyone interested in visiting the 

 planting is welcome to do so; each system is clearly 

 labeled. 



Small Central Leader 



With the small central leader systems each tree 

 is supported by a 1-inch (O.D.) conduit pipe stake 

 protruding 7 feet above the soil surface. Trees are 



spaced 8 feet in the row and 14 feet between rows, 

 giving a density of 389 trees per acre. These trees 

 will be trained with a relatively low input technique, 

 using zig-zagging of the central leader, limb re- 

 newal, and other pruning techniques as described in 

 the New England Apple Production Guide. The best 

 way to describe them is that they will be maintained 

 similarly to free-standing, semi-dwarf trees, but will 

 be small and supported by a stake. 



After laying out the orchard, tree holes were dug 

 with a 24-inch, tractor-mounted soil auger to a depth 

 of 24 inches. Conduit stakes were driven 12 inches 

 into the bottom of the hole. After planting, trees 

 were headed at 34 inches above the soil. Each tree 

 was tied once to the post using a mechanical tying 

 device (Max Tapener™). The costs of establishing an 

 acre of small central leader trees are detailed in 

 Table 1. 



Slender Spindle 



The slender spindle system also produces a 

 central leader tree. In this trial slender spindle trees 

 were established similarly to the small central 

 leader in that they were individually supported on 

 conduit pipe stakes; however, they are spaced 6 x 14 

 feet (519 trees per acre) and will have a more inten- 

 sive training regime. Limbs will be tied down to 

 encourage early fruiting and reduce growth, the 

 leader will be bent to reduce growth, and summer 

 pruning will be used to reduce potential regrowth. 



Establishment was similar to that described for 

 the small central leader, except the time required to 

 perform each task was increased because of the 

 greater number of trees per acre. Costs are de- 

 scribed in Table 2. 



Vertical Axis 



The vertical axis tree is also a central leader, 

 except no attempt is made to control the growth of 

 the leader. Trees are supported by tall stakes. As 

 a tree grows, the leader, if not pruned, will eventu- 



Fruit Notes, Fall, 1990 



