When pruning fruit trees for best production, remember
these basic concepts:
(1) Pruning invigorates and results in strong growth
close to the pruning cut. Pruning reduces the number of shoots so
remaining shoots are stimulated. However, total shoot growth and
size of the limb is reduced.
(2) Two types of pruning cuts are heading back and
thinning out. Heading is cutting off part of a shoot or branch
apical dominance and removes stimulates branching and stiffens the
limb. Thinning cuts remove the entire shoot or branch at its
junction with a lateral, scaffold, or trunk. Thinning cuts are
less invigorating, improve light penetration, and can redirect the
(3) Limb position affects vigor and fruitfulness.
Vertical or upright branches, typical in the tops of trees,
produce the longest shoots near the end of the limb and tend to be
excessively vigorous and not very fruitful. Fruit are often of
poor quality and subject to limb rub. Limbs growing slightly above
horizontal are more apt to develop a uniform distribution of vigor
and fruitfulness. Light distribution tends to be even, and because
fruit hang along the branch, they are less prone to limb rub.
Limbs growing below horizontal tend to develop suckers along the
upper surface. Excess sucker growth will result in shading.
Hangers, or limbs developing on the underside of branches or
scaffolds, are heavily shaded and low in vigor. Fruit developing
on such wood is of poor size and color.
Training and Pruning Apple Trees
Non-Bearing Apple Trees
The objectives of training, directing, or modifying growth into a
desired form include early fruit production, development of an
optimum tree structure for support of future crops, and optimum
fruit quality conditions. These objectives can be met by
maintaining a proper balance between vegetative and potential
fruiting wood. Excess shoot growth will delay the onset of
fruiting. Thus, excess pruning of young, non-bearing trees will
delay the beginning of fruit production in the life of that tree.
Training should be emphasized in the development of trees, with
pruning used as a tool in the training process to redirect limbs,
stimulate branching when desired, or to remove growth that is in
an undesirable location. Pruning should not be used to invigorate
growth in an attempt to compensate for poor fertilization, poor
weed control, or drought conditions.
Future pruning of an apple tree is greatly affected by
early training. Much of the pruning of young, bearing trees is the
result of errors made in training in the early life of the tree.
Thus, it is imperative that training begin early. A delay for the
first 3 to 4 years will result in a poorly-developed, weak tree.
Correction of such a problem, usually with heavy pruning, will
only further delay and decrease fruit production.
An integral part of a tree-training program is
limb-spreading. Limb orientation affects vigor in various ways. An
upright or vertical limb produces the longest shoots near the apex
and tends to exhibit high vegetative vigor. This is known as
apical dominance. Often, fruit hang down against the limb and are
subject to rub. As limbs are oriented away from vertical, they
exhibit reduced vigor of shoots near the apex, more uniform
branching along the shoot, and favor development of fruiting
spurs. Fruit hang along the limb and are less prone to rub. A limb
orientation around 60° from vertical is desired. However,
horizontal orientation of limbs results in the development of
vigorous water sprouts along the upper surface of the limb, at the
expense of potential fruiting spurs.
Thus, correct limb-spreading (near 60° from
vertical) can be used to develop a proper balance between
vegetative and fruiting growth. Limb-spreading should begin early,
as many cultivars, such as Red Delicious (particularly
spur-types), naturally develop narrow crotch angles. If these
narrow crotch angles are not widened (greater than 35°), a
situation can quickly develop in which bark is trapped between the
trunk and scaffold limb (bark inclusion). This bark inclusion
prevents layers of annual wood from growing together and creates
the potential for splitting. If these narrow crotch angles with
bark inclusions are allowed to develop, later attempts at
limb-spreading may result in splitting of the crotch. Two
objectives exist for limb-spreading: 1) development of a strong,
wide crotch angle (greater than 35°) free of bark inclusion
and 2) limb orientation at 60 degrees from vertical to balance
vegetative and fruiting growth. To derive the benefits of
limb-spreading, the crotch must be physically strong, to undergo
spreading without splitting.
Poor pruning practices are not a wise substitute for
proper limb-spreading in the training of upright scaffolds.
Improper pruning cuts will not change the crotch angle, improve
limb position, or aid in the control of vegetative vigor. Scaffold
limbs should be spread and lower laterals removed if necessary.
Trees must be pruned at planting for several reasons. The top of
the tree must be brought into balance with the root system, which
is usually damaged in the nursery digging operation. Pruning
forces the growth of laterals from which future scaffolds will be
Head spur types and semi-dwarfs to a height of 30 to 35
inches. Standards are headed to 40 inches. If feathered (branched)
trees are planted, they should be headed to a strong bud to
stimulate growth of the central leader.
Feathers desirably located can be retained as scaffolds
and should be headed. Undesirable feathers should be removed.
First Growing Season
Scaffold selection can begin in the early summer, especially on
cultivards developing narrow crotch angles. Shoots developing
below the lowest desired scaffold should be removed. Generally, in
the first year, 4 to 6 good scaffolds, 5 being ideal, can be
selected that are evenly distributed and not directly above one
The vertical spacing between scaffolds can vary from 3
inches to 12 inches depending on the ultimate size of the tree.
Limbs with crotch angles less than 35° should be spread or
removed. Hardwood toothpicks, or clothespins can be used if
training is done in early summer while shoots are soft. Short
pieces of #9 wire can also be used.
Shoots undesirably located should be completely removed
at this time.
First Year Dormant Season
Select shoots to be retained as scaffolds if this was not done
earlier. Selected scaffolds to be spread or tied in the spring
before any pruning is done. Spreading changes the shape of the
tree and may influence pruning decisions. Remove shoots that were
not selected as scaffolds. The central leader should be headed to
maintain dominance if needed and induce branching. This is done 3
to 5 inches above the point where the next tier of scaffolds is
desired. Refrain from heading scaffolds unless they need to be
shortened or stiffened. Generally a year-old shoot naturally
branches in the season after development. Spreading that scaffold
will encourage uniform branching. However, a scaffold will often
exhibit excess vigor and upset the balance of the tree. Heading
can also be used to encourage growth and branching on spur types.
Second Growing Season
Limbs not previously trained can be easily weighted down, spread,
or tied early in the growing season. The new tier scaffold limbs
can be selected and trained at this time if the tree is growing on
a standard semi-dwarf rootstock. These should be well-spaced
without shading the lower scaffolds.
Second Year Dormant Season
Some of the scaffolds that were selected and spread in the first
year may turn up and resume vertical growth. Longer spreaders,
weights, and/or tie downs can be used to spread the limbs back to
the desired orientation. The smaller spreaders can be moved
further up into the tree. Again, scaffolds should be spread before
pruning. The central leader should be headed again to maintain
vigor and stimulate branching if needed.
Continue training and pruning following the previously discussed
principles of central leader dominance and proper scaffold
selection and training. Scaffolds should be maintained in a 35°
to 60° orientation. A conical tree shape should be
maintained. Thus, the upper scaffold should be shorter than the
scaffold below it. After the third year, upper scaffolds can be
shortened with the use of thinning cuts to remove shoots at the
junction with a lateral scaffold or trunk. Thinning cuts are less
invigorating than heading cuts, improve light penetration, and can
redirect the limb.
Remove crossing branches and vigorous water sprouts.
Shoots growing up into and toward the center of the tree should be
Once the desired tree height is reached, the tree can
be maintained by annually cutting back to a weak lateral on the
central leader. This will maintain vigor in the top center of the
tree while maintaining desired tree height.
Bearing Apple Trees
When pruning is underway, older, bearing trees should be pruned
first. Young, non-bearing apple trees and stone fruits can be
pruned later to minimize chances of winter injury.
The balance between vegetative and fruiting growth is
influenced by the crop load, fertilization, and pruning. Fruiting
may be poor because vigor is too high or too low. Excessive vigor
can be the result of inadequate fertilization, no pruning,
excessive cropping, or shading of fruiting wood. Good fruiting
wood requires moderate vigor and exposure to good light levels.
Light is the source of energy that produces the crop.
Bearing wood that is shaded is low in vigor and produces small,
poorly colored fruits. Good light exposure is necessary for the
development of flower buds as well as optimum size, color, and
sugar content of the fruit. Studies have shown that a typical tree
canopy is composed of different layers or zones in respect to
light exposure. As shown, an outside zone of leaves and fruit
receives a high proportion of direct light and light levels above
those required for good growth and fruiting; a second zone
receives adequate light exposure; and a third, inner zone receives
inadequate light exposure and is unproductive.
The relative proportion of these zones in a tree is
influenced by tree size and shape. As tree size increases, the
percentage of the tree that is shaded and unproductive (third
zone) increases. Trees that have wide tops and narrow bottoms, an
inverted pyramid shape, also have a high percentage of shaded
areas in the tree canopy. Trees should be cone-shaped, or larger
at the bottom than the top, to maximize adequate light exposure.
Good light exposure in the tree canopy can also be maintained by a
good pruning program. Ideally, pruning should remove unproductive
wood and develop a uniform distribution of vigor and light
exposure throughout the tree. Proper pruning can also help to
maintain desired tree size and shape.
Pruning should be done on a regular basis and consist
of moderate cuts made throughout the tree to distribute vigor and
provide good light penetration. Heading cuts should only be used
where branching is desired or in areas where vigor is low.
Drooping or low-hanging branches should be removed or pruned to a
lateral that is positioned above horizontal. Remove crossing,
dead, diseased, parallel, or damaged limbs. Water sprouts should
be removed unless one is needed for the development of new bearing
surface. Water sprouts can be easily removed by hand as they
develop in the summer.
Without regular annual pruning, trees often become
overly thick, and irregular or alternate bearing may occur. Spray
penetration is reduced, and pest problems, such as scale, may
develop in the dense areas of the tree. With this type of tree,
make many thinning cuts throughout the tree with emphasis on the
upper, outer portions of the tree. This will open up areas into
the tree canopy as well as re-establish good tree shape.
Avoid bench cuts to outward-growing limbs unless
necessary. Such cuts result in weak limbs and an umbrella shape
that creates a sucker problem. Remove no more than 2 large limbs
or 30% of the tree limbs per year. If large amounts of pruning are
required, it should be spread over a 2 to 3 year period. In
addition, such pruning should be preceded and followed for 1 to 2
years by a reduction or elimination of nitrogen application,
depending on soil type, variety, and grower experience.
The excess vigor that can result from severe pruning
can decrease fruit quality. The effect is much the same as from
excessive nitrogen application and may include excessively large,
poorly colored, soft apples which will not store well. Vegetative
growth competes with fruit for calcium; thus, under conditions of
excessive vigor, cork spot may develop.
Hedging and topping should only be used to maintain
tree size when trees are at or near desired size. Such pruning is
often used in an attempt to reduce tree size. Misuse can result in
a disruption of vigor and loss of yield which may take several
years to control. Hedging and topping (mainly heading cuts),
especially of one-year shoots, induce masses of shoots close to
the plane where cutting takes place. This localized invigoration
of shoots can shade and weaken inner areas of the tree.