Hello, my name is Mike Parker and I'm the tree fruit Extension Specialist at North
Carolina State University. Today we're looking at some pecan trees. When we
start talking about pecan trees and pruning, it is very crucial in North Carolina that
we prune our trees properly. In North Carolina we have a high probability for
tropical storms and hurricanes that result in serious damage to the pecan
trees. So in North Carolina we want to have a central leader tree, a strong
central leader tree growing up which our branches come off. Once we plant our
pecan trees that pruning starts from the day that we plant those trees. When we
plant a young tree we will come in many times and we will cut off approximately
the top third. One of the reasons we cut off the top third is to get buds that
are well spaced out. If we would look at the tip of young pecan growths, note
how closely the buds are placed together. If we would allow all those when the
growth begins in the spring we would have a witch's broom, if you will, a very
concentrated area of upright growth. The way that we can do that is we cut out
approximately 1/3 of the top of the tree. By removing a top third of the tree
notice that the buds are much wider spaced out so when the growth begins in
the spring of the year we can have a wider distribution of those branches. It
is also important to look at the buds of a pecan tree. At each node there are
usually at least three buds. The ones that stick out maybe stick out a
half-inch - that would be called the primary bud. The growth orientation of that
primary bud is very upright. The only growth in the tree that would be useful
for it be the central leader. The bud right beneath that would be the secondary,
comes up more at a 45 degree angle, and the tertiary third bud would grow out at
a flat angle. We can look on this tree beside me, the tree was cut off when it
was planted. Notice the top bud that grew out - both the primary bud and the
secondary bud grew. So what we would do is we would come in and we would remove
the under branch here allowing the upright tree to grow. The new growth here
we would come back in and cut it by third, allowing the central leader to
continue the upright growth. With the pecan tree we'd also want to eliminate -
again we can see here the secondary buds - a primary bud very upright -
a secondary bud coming out right. At this point we remove this because we do not
want the competition with the leader of these trees. And a two-year-old pecan
tree like this, we would maintain our central leader, then we would leave
remaining growth on the base as long as it was not upright growing, realizing
that in North Carolina any growth from approximately six foot down will be
temporary. We will leave these young branches until they're approximately an
inch in diameter at which point they all be removed. It is nice to have videos and
publications that tell us how to prune trees, however we have to realize that many
times the circumstances we were in are not perfect. Deer browsing, storms can
come in, and here's a two year old tree that has some issues. Again notice we
have a multi leader tree, we have branches that came off here. The side
branch here is stronger than what would have been the leader. So a tree like this we would
want to maintain the growth, realizing this would be the central leader. At that
point in time we will come in and cut off all extraneous growth that is low. If
you lower our knee height for a herbicide strip. And then you notice also
we have a problem here with crotch angles. So we will come in remove that -
going back to a newly set tree. This may look brutal however we look at the
long-term growth of this tree and in three years from now you'll never know
the difference except you will have a well-maintained
central leader tree. This is the pecan tree that's been planted for two years.
Again, the tree was headed off at planting, so we had upright growth. We
will come in now and maintain this, and select the central leader. It would be here,
but notice that in the top two nodes both the primary bud and the secondary
bud broke or grew, if you will. So we would do is we would come back in and
select our central leader - this would be our upright central leader. Eliminate
competition for approximately a fist width and then we remove upright
branches on the tree leaving the ones coming out at a angle to feed the tree
in the initial years, realizing all these branches down here will be removed when
they're approximately one inch in diameter. The final thing we would do on
a tree like this is we would go back, and since we have selected our central
leader, we would cut it back by approximately a third so that we get the
buds spaced out to maintain the central growth. Again as we talked about earlier
not all trees grow according to plan. If we would look at this tree, a heading cut
was made in this area here approximately two years ago.
Notice the resulting growth - two branches or three branches came off in the same
location. That is a very dangerous situation, very unhealthy for the tree,
because with this rigid bark and sharp crotch angles, those are very weak.
If we will look at a side branch where it has a similar type of forking we can
see a sharp crotch angle. The problem is is when the forces put on that, it
results in the tree splitting and breaking. If we would have had the same thing
occurring here in the trunk, we would have lost the productivity of this tree.
It would have to be replaced to be profitable. So we would come in - so we do
not want that to happen under a tropical storm or hurricane - so we would come in
and eliminate these sharp crotch angles maintaining the upright growth of
our tree to a central leader. And we would prune this very similar as we had
done the other ones, again, having a heading cut was made here last year, we
have three competing shoots, we will come back in at that point time and select
our single leader - go back up here as we talked about the central leader
maintained by cutting back by about a third. As we move down this tree again we
will leave the side branches except these that are very upright - the
one here that I showed you how it was going to break - we will remove those as
well, leaving the branches in the lower
portion of this tree to provide resources in the initial years. We're
looking at another pecan tree that has been in the field for three years. Notice the
heading cut was made here, at year one, another heading cut was made here and
then another heading cut was made here last year. So again we want to maintain
the upright central leader of the tree we have some issues - we have some sharp
crotch angles - so the first thing you'll do is maintain - we will maintain this as
our central leader, we will get rid of competing upright shoots with the
central leader, then moving down if they're coming out laterally we will leave
them, and then we'll cut out some large competing branches here. So that's what
you'll do this young tree and then the final cut will make is coming in with
the central leader and cutting it back by approximately a third.
One of the reasons that we head back the leaders of the young pecan trees is to
get away from the witch's broom or crow's feet that result from all the
buds breaking. This is a good example of what has happened at the terminal. All
those buds have broken resulting in growth that would be somewhat weak. Again
as the trees get older when we get heavy crops - leaf and nut crop - the resultant
breakage under heavy winds, and notice when they break off they go into the
tree trunk. So when we come in, we cut the trees back to get the buds that are
spaced out, getting away from the crows foot that results. Maintaining the
central leader of young trees is not a problem and can be done from the ground.
However, as trees grow and age and mature, pruning them can be much more of
a challenge. As behind me, we look at the tree, we have a strong central leader.
However we go up approximately 15 feet we see we have three major branches that
are competing for the central leader. If we do not rectify this situation when we
get heavy storms there's a good chance the tree will split in the top.
So we will come in with a pole pruner and remove two of those maintaining the
upright central leader. To remove the tops pecan trees we will be using an
extendable chainsaw pruner, I believe this one extends to 11 foot six inches.
When using chainsaw equipment make sure that you use the proper safety equipment.
As we continue to maintain the central leader tree for pecan trees in North
Carolina, we can start out and we do our work from the ground for the first four
or five years, then we can use our pole pruners and pole chainsaw pruners to go
up to about twelve or fifteen feet. However after that it becomes an issue.
At that point in time, we either allow the trees to become multi branch, which
are a serious problem with tropical storms and hurricanes, or we come and
use a lift of some type to get us into the tree. This is an automated lift that
I'm working from here. It has automatic chainsaw pruners as well as loppers that
are run off the hydraulics from the unit below.
This is another issue as we move up the tree you can see these sharp crotch
angles that we have. These are always going to be a problem since this is a
permanent tree that will be here for many years, we will come in and eliminate
these branches as well. When we remove these larger branches, we come in and
use two cuts, as you've noticed. We will come and make a cut out approximately a foot
away from the tree, so we can drop down branches without putting any harm in the trunk. .
Again as we work our way up the tree we'll do the same type of thing. All
these are some major cuts. These cuts maybe should have been made several
years ago. Realize at this point in time we're looking for a long term yield of
these trees that will tolerate our heavy crop loads as well as the tropical
storms that we experienced in many times of this part of North Carolina.
Again we came in with this permanent tree, we've developed a central leader and got rid
of the competing major branches coming off from the leader, to provide higher
long-term yields over the life of the orchard.
For more information please lookat the North Carolina Pecan Growers website
or look at NC State University's Cooperative Extension Service website as well.
Thank you and good luck with your endeavor.