Pruning Apple Trees


Uploaded by TheUniversityofMaine on 31.05.2012

Transcript:
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Renae Moran: Hello. My name is Renae Moran and I'm the tree fruit specialist at the University
of Maine. We're here at the Agricultural Experiment Station in Monmouth. We call it the Highmoor
Farm.
Today we're going to have a demonstration on pruning apple trees. It is the dormant
season, the best time of the year to do the majority of pruning for our fruit trees. You
want to prune your fruit trees between January and before growth starts in spring. We're
in the month of April right now, which is an ideal time for pruning because a lot of
the snow has gone, but growth has not yet started.
Before pruning, it's important to know why you are pruning your fruit trees. There are
several reasons for pruning fruit trees that are part of a hobby orchard.
Today we're going to prune this fruit tree to improve fruit production. But some people
have apple trees that are a part of a landscape. In that case, you would prune fruit trees
for aesthetic reasons, because of the shape of the tree and because of the flowers of
the tree.
But this tree, we'll prune for improved fruit production. To do that, we're going to prune
it so that it gets the most amount of sunlight throughout the tree canopy.
The tree behind me has already been pruned. When we pruned this tree, the first thing
we did was to select which limbs to keep, and then to prune the rest of the tree so
that each limb gets the most amount of sunlight as possible, without over-pruning the tree.
This tree has a typical shape for a semi-dwarf apple tree. It's a cone-shaped tree, where
the lower limbs are the longest limbs on the tree and the upper limbs are shorter than
the tree. There's only one main trunk or leader to the tree.
This type of training gets the most amount of sunlight throughout the entire tree canopy.
You'll notice that the lower limbs don't have other limbs growing right on top of them.
Those were pruned out or were not allowed to grow, and the upper limbs have been shortened
so that they're not growing down and into the lower limbs.
The tree is pruned back in the top to be a certain height. The height would be a personal
preference, usually based on how tall your ladder is or how high you're willing to reach
into the tree.
You'll also notice that the limbs have been pruned so that things growing underneath or
growing in a downward fashion have been pruned off, and shoots that are growing straight
up are no longer in this tree. This vertical or hooked-downward growing orientation cuts
out a lot of sunlight, and these types of branches don't produce the best fruit. So
they get pruned out.
Then at some point, you have to know when to stop pruning to prevent yourself from over-pruning
the tree. You don't want to prune out any more than one-third of the total tree canopy.
Otherwise, you could end up overly invigorating the remaining growth on the tree so that the
tree produces too many water sprouts the following season.
Woman: There are two basic types of pruning cuts, heading cuts, and thinning cuts. To
make a thinning cut you would remove the shoot or limb at its base where it joins the previous
growth like this.
When you're making a thinning cut it's best to prune back as much of it as possible into
the crown or the circles surrounding the base of that shoot, this prevents the regrowth
of water sprouts. The smaller the stump you leave, the fewer water sprouts you should
have next year. Pruning back into the crown or the collar of the branch helps the pruning
cut to heal.
The other type of pruning cut is a heading cut and in this case you're pruning into the
growth, leaving behind the part of that shoot. This would be a one-year-old shoot. A heading
cut into that would be like that. When you remove the tip of that shoot it releases these
buds from growth inhibition and you get a bushy type of regrowth the following season.
We rarely make this type of pruning cut when we're pruning fruit trees. So in this case
I'm going to head it back into the two-year-old section like that. But a more severe type
of heading cut would be to be pruning into this section of the limb. We already have
branches that have developed. By making a heading cut into this part of the branch we're
not likely to stimulate the growth of new shoots. So we don't get a profusion to follow.
This type of pruning cut is very useful for making the branches shorter where you have
trees growing into each other. A heading cut into the older sections of the branch will
make it shorter and it's also useful in the top part of the tree to bring the height down.
It's also important to pay attention to how many flower buds are on the apple tree when
you're pruning it to prevent yourself from pruning out too many. Flower buds on an apple
tree have a characteristic shape that is very different from leaf buds. Flower buds are
found at the tips of short shoots and spurs. Spurs are just shoots that grew a few inches
or less in one season.
Flower buds are fat in contrast to leaf buds which are much smaller and shorter or more
pointed. Laterally along the shoots and spurs apples normally form leaf buds, in rare instances
they'll form flower buds. So pay attention to how many flower buds the tree has. If it
has a lot of flower buds in this year it's OK to prune off a number of these shoots that
have flower buds.
We've reached a point where the tree is nearly finished pruning especially on this side.
There's still a lot of shoots on that side that can be pruned out. If you like to have
a lot of flowers on your fruit trees then this would be a great place to stop pruning
it. But if you're pruning it to get the best colored, largest fruit this tree could still
use more pruning.
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