Agriculture Reference
In-Depth Information
acre were considered high-density. Today, apple orchards of 500 to 1,000
trees per acre are common, and some systems have more than 2,000 trees
per acre.
In trials conducted at Cornell University, researchers evaluated various
apple training systems. The lowest yields for the first 4 years of the trials
came from freestanding trees trained to central leaders (218 trees/acre). For
trees on supports, slender pyramid training (444 trees/acre) produced the
lowest yields, followed by slender axis training (726 trees/acre). The tall
spindle system (1,307 trees/acre) produced the earliest and heaviest yields.
Figure 3.6 shows how tree planting density affects apple yields.
In related apple training system trials in New York, researchers estimated
the earliest financial breakeven points for new orchards using each system
(shown on the next page). Growing apples is not a get-rich-quick enterprise!
Slender axis:
12 years
Tall spindle:
13 years
Super spindle:
14 years
Vertical axis:
14 years
Slender pyramid:
17 years
Trials have been conducted in British Columbia, Pennsylvania, and other
locations around the world with generally similar results. For new commer-
cial apple orchards, most North American experts now generally recommend
some variation of a vertical axis or tall spindle design.
Pear Training Systems
Pear orchards, particularly in North America, have traditionally been low- to
medium-density plantings of freestanding trees or trees trained to palmette
shapes and sometimes supported on trellis wires. Even today, that approach
remains common in the United States. Internationally, research on high-
density pear plantings has paralleled, but lagged behind, that on apples. Be-
