High density apple orchard management

              8 High Density Apple Orchard Management
tion, bagging, bending, heading, leader renewal,
or notching, etc., which will be discussed later in
the “Leader Management Techniques” section of
this publication. Research in North Carolina has
found that vertical axis trees, where the leader is
not manipulated, do not have continuous branch-ing
along the leader, which is required for a pro-ductive
and profitable tree. These trees have
lower branches, an area of 2-4 feet of blind wood,
or unbranched leader, and branches at the top of
the tree. Therefore, the leader must be manipu-lated
in some manner to ensure continuous
branching.
All lateral branches with wide crotch angles
should be maintained for the first 3-5 years to
maximize early fruit production. A lower whorl
of scaffolds should be identified as permanent and
others should be removed as shading becomes a
problem. There may also be a second semi-per-manent
whorl approximately 12 inches above the
first that should also be identified and removed as
shading becomes a problem. Permanent whorls
are maintained in the lower portion of the tree as
there is some concern about a lack of vigor and
light in that area of the tree. The permanent
whorls should be spread out to approximately 85
degrees from vertical to encourage lateral branch-ing
and floral initiation. Above the second whorl
of scaffolds all branches should be renewed every
3-4 years. These lateral branches will be cropped
for several years. As the diameter of the lateral ap-proaches
50% of the leader’s diameter, the lateral
is removed by a cut at a downward angle, referred
to as a Dutch cut (Figure 1). This cut allows la-tent
buds on the bottom of the stub to grow, giv-ing
rise to lateral limbs with wide crotch angles.
It is also imperative to maintain the conical shape
of the tree to allow optimal light distribution
within the canopy. However, in the first 3-4 years
there should be minimal pruning done, using tree
training techniques such as bending, spreading,
etc. approximately every 6 weeks during the
growing season.
High Density Training Techniques for
the Southeast
Characteristics of and requirements for slender
spindle–type trees follow:
• Pyramid-shaped tree like the central leader.
• Height controlled at 8-10 feet.
• Maximum width of tree limb spread 6-7 feet.
• Lateral branches continuously along the cen-tral
leader.
• Summer training and pruning to control
tree vigor (primarily in the first 4 years).
• One or two permanent whorls of lateral
limbs can be established in the lower portion
of the tree, providing limb diameter doesn’t
compete with leader diameter.
• Leader management for profuse lateral
branching is important to generate fruiting
wood production and to increase the num-ber
of growing points to control vigor.
• Lateral shoot positioning is important to
control vigor and encourage fruiting. This
positioning is also necessary to stimulate
secondary branching.
• Non-branched areas of the leader are areas
of lost fruit production. Thus, successful
leader management is directly related to
early and total fruit production potential.
• Trees must have a permanent support sys-tem
for the total height of the trees to at-tach
the leader to every 15-18 inches. This
support holds trees stable in soil and sup-ports
the fruit load. If tree vigor is limited by
inadequate soil moisture or ground cover
competition, tree vigor and growth will be
reduced and tree training techniques will not
be as effective.
Figure 1. A Dutch cut is a technique used to cut
lateral branches to an angled stub, allowing latent
buds at the bottom to grow. (Note wide crotch
angle.)