Hello I'm Mike Parker the fruit tree extension specialist at North Carolina State University
. Today we're in a high density aztec fuli planting at the Mountain Horticulture Crops
Research Station in Mills River North Carolina. many growers in establishing new orchards
these days are planting higher density with a higher number of trees per acre. The reason
for these high density orchards is that the trees we are using are very precocious they
bear fruit much earlier. Having fruit much earlier results in greater profitability for
the grower. Also they can realize the extra revenue from having newer varieties. When
those new varieties come into production the high value early in the life of that apple
realizes great profits for the growers. Also these high density systems allow most of the
work to be done from the ground, instead of having workers climb up and down ladders for
thinning, for pruning and for harvesting. The high density systems also allows the opportunity
for mechanization, reducing the amount of labor capital required. However, for these
high density orchards to be successful and profitable, they must be managed very well.
High density orchards in North Carolina are probably going to be in the density of approximately
500 to 600 trees per acre. Trees within the row will be spaced approximately four to six
feet apart with the rows spaced 12 to 15 feet apart, depending on the elevation and the
terrain of the land. As I mentioned earlier, in order for the high density systems to be
productive and profitable, they must be managed very well with several very specific considerations.
The first is, a dwarfing root stock must be used. This tree that we are standing next
to is an M.9 337 . It is a dwarfing root stock. Also, if you look at the base of the tree,
the root stock has been planted approximately 6 inches above the soil line. The greater
the amount of the root stock shank out of the ground, the greater the dwarfing on the
tree will be. Most high density systems today require at least 4 to 6 inches of the root
stock shank to be planted under the ground. Another very important criteria is a support
system. Here we are using angle iron - a ten foot angle iron, two feet is driven into the
ground. And that is to support the trees early in their life. The stake is there to support
the tree and the fruit load within the second or third year. Here we are using metal stakes
for research purposes. However, any type of system should be suitable. Many times a wire
system, whether it be a wire at 10 foot, with bamboo stakes, or a multiple wire system - four
or five wire system - is used. It's what is most economical for the grower, and for their
management system. Another key criteria with high density systems is an irrigation system.
The irrigation system we are using here are micro sprinklers. They apply approximately
15 gallons of water per hour in a 6 to 8 foot radius, usually to the drip line of the tree,
with a herbicide strip. You will also notice that we do have a vegetation free strip underneath
the tree so that we do not have grass that is competing with the tree for water and nutrients.
With high density systems, there also has to be an associated training system. Several
of the primary ones now is a tall spindle or, what we are growing here, is a modified
slender spindle. Our trees here are splayed 6 by 14 for approximately 500 trees per acre.
We have a support system to 8 foot with a tree height of approximately 10 foot. Characteristics
of this tree - it does have a strong central leader. One main trunk all the way up. Then
we have lateral growth coming off from this, and all of this lateral growth is horizontal
or below. The difference between the tall spindle and the modified slender spindle as
we would have here, is that we keep one major whorl of permanent scaffold at the base of
the tree with the rest of the growth on the tree being renewed. The tall spindle tree
will have growth renewed consistently along the entire leader. To renew that growth, we
would come in and use a dutch cut. When the diameter of the lateral branch gets anywhere
from a half to two thirds the diameter of the leader, it is cut off during the winter
with a dutch cut. This is a typical dutch cut, cut at an angle, to decrease the surface
on top, allowing a greater surface on the bottom. You get branches to grow out the bottom
there, coming out at a wide crotch angle. We allow them to regrow ten inches long, and
then they are weighted down. Another way to train branches down to the stake of wire trellis
system is with thin gauge wire - come in and put it through the stake, and then wrap it
loosely around the branch. Until that point we will allow these lateral branches to come
out and crop. They are pulled down to encourage fruiting, and then we will prune these branches
back to lateral growth during the dormant season. The ultimate height of trees in high
density systems is no more than double the free alley or free row width. If we have fourteen
foot rows, we have 6 foot taken up - 3 foot from each side - we have 8 foot middles. So
the height of this tree should be no more than 16 foot. However, in our situation, we
would allow these trees to go to 10 to 12 foot for labor purposes.
Some of the major mistakes that we see growers making with these high density systems - the
first one we see is planting the root stock too deep, allowing that root stock union to
be below the soil line after the soil is settled, which results in the scion rooting, the top
rooting, result in a full sized tree. The other thing we see is inadequate support system,
support systems that cannot support the weight of the tree and the fruit, especially if we
get heavy winds, tropical storm winds, or if we get early ice and snow storms and the
entire system collapses. And the last thing many times we have problems with is allowing
the lateral branches to become too large and not renewing them quick enough. This is a
prime example here. We notice that this lateral branch is larger than the central leader.
That branch should have been cut out at least one, maybe two years ago, with a renewed dutch
cut. This is a high density orchard, Apple Hill
Orchard, in Hendersonville, North Carolina. Steven Godfrey is the orchard manager here.
This is early Fuji and M.9 going into the third leaf. The trees were planted as whips.
This year they are looking somewhere around 300 bushels per acre, on a 4 by 14 tree spacing
for 777 trees per acre. This is a new orchard established at Apple Hill Orchard in Hendersonville
again. They planted G.11 with early Fuji on top. This is the first year of planting, it
will have a 4 wire trellis. The posts have been put in, the wires will go in this winter.
If you will notice, all of the lateral branches have been pulled down. Here they are using
rubber bands, pulled down below horizontal. This would be a 4 foot spacing so they have
the lower permanent whorl scaffolds. With the remainder of the tree going to be renewed
as the tree matures. We're in the orchard of Wayne Pace in Dana,
North Carolina. Wayne has approximately 25 acres of high density tall spindle trees.
He's using root stocks of B.9, M.9 and some 26 and some of the weaker varieties. Tree
spacing ranges from 4 to 6 foot within the row, and 14 foot between the rows. He's averaging
518 to 777 trees per acre using approximately 10 or 12 varieties - the newer varieties that
are in high demand at local retail outlets. One of the main issues that Wayne has when
he gets close to harvest is with damage from the birds. The birds come in, they peck all
of the apples and cause a significant amount of damage. So what you have been hearing going
on in the background, you hear the propane cannons that he uses across the 25 acres.
He also has the bird scarer, or bird guard alarms, that basically broadcast a distress
signal for birds of concern in his orchard. You can hear that out here. Again, it has
been very effective in minimizing the bird damage in his orchard. However, there are
issues with neighbors. But again, like the deer, the neighbors become used to it over
time as well. In addition to the bird alarms that are used
to deter bird damage in this orchard, wind machines are also used. Wind machines are
used to protect the crop during the spring from frost and freeze damage. In North Carolina
frost and freeze damage is a major issue during bloom. The difference between a full crop
and no crop many times is only 3 to 5 degrees. The wind machines are one way we can minimize
potential for frost and freeze in the orchards. Especially with the high establish costs for
a high density orchard.
We are at the orchard of C. L. Henderson in Hendersonville, North Carolina. This is a
high density system. The trees are spaced 5 by 14. All the trees are on Bud 9. The scion
variety is going to be Pink Lady and Fuji. As we talked about earlier having a substantial
support system is essential. In this orchard here they are using 12 foot poles within the
row, with 2 foot driven in the ground. They have 5 wire - high tensile wire - spaced 2
foot apart. Then the trees are tied to it. Again, the system is not here for moral support,
it's here for physical support, and they tie the trees at every wire. And then they also,
from the tree up, use string. The leader is wrapped around that until it reaches the next
wire. You'll notice with the training system that clothes pins are used in the trees as
growth emerges in the spring - upright growth - the clothes pins are used to place around
the trunk of the tree to get that wide crotch angle. Then as the branches become longer,
they come in and use wires. A low gauge wire is used to come in and pull those branches
below horizontal. They wrap one end of the wire around this wire here and then they loosely
wrap them over the branches here. They can move them and place them throughout the season
to make sure the entire branch stays below horizontal during the growing season.
Hopefully this video has given you an understanding of some of the higher density apple systems
used in North Carolina and how they can be successfully be used in your orchard.