Macadamia Nuts in Hawaii: History and Production - ctahr ...

columnar, with others falling in between. 'Keauhou'
(HAES 246) and 'Ikaika' (HAES 333) are
basically dome shaped, 'Keaau' (HAES 660) and
'Ka'u' (HAES 344) are columnar, and 'Kakea'
(HAES 508) can be either domed or columnar.
These trees need to be pruned somewhat differently
when planted together. However, to reduce
the ills of tree shape and yet permit crosspollination,
the varieties are better planted in
alternate rows instead of alternate trees.
Planting
The planting holes to receive the trees in the
field should be laid out and completely prepared
before planting operations begin. This is very
important since the delicate grafted trees,
especially when bare rooted, should not be left in
the field unplanted in the hot summer. The tree
holes can be dug with hand tools, posthole diggers
(Fig. 58), or a backhoe. The holes should be hand
cleared, if necessary.
Planting method is an individual matter and
can vary depending on individual preference and
the situation. However, a few general words of
caution may bring the more common problems
into better focus. The grafted trees are living entities
with established root systems tha t need to be
handled very carefully and placed in their proper
orientation. When using bare-rooted trees propagated
in nursery rows, the taproot should be
placed in a straight up-and-down position with
all obstructions removed. The la terals should be
aligned to spread from the main root-stem axis
like wheel spokes attached to a hub, and thinned,
if necessary, to reduce congestion and permit the
remaining laterals to radiate more strongly as
definite la terals. The roots thus placed should be
tamped in gently, to permit a firm foundation.
Grafted trees propagated in containers have to
be treated somewhat differently prior to field
planting. By the nature of root growth and extension
in a container, as often as not, some roots will
assume dominancy in growth extension and will
begin to circle the side of the enclosing container.
Some others might extend downward or vertically
onto the table holding the containers, or into the
soil if placed on the ground. Whichever the case,
before planting, sever the circling extension to
permit a radial extension, and sever the downward
or vertical extensions, if necessary, at a point to
permit further development in the field. Some
trees do neither of the above, but the roots will
Figure 58. The original posthole digger fabricated by Slubenberg
and Company in Hilo for use at Keaau Orchard in the
early 1950s. Note the wide auger especially designed for
macadamia on aa lava land. This unit derived its power
from the power takeoff on a tractor. In recent years, a backhoe
has been used 10 further red uce cost.
appear as pinpoints at the container surface. In
such cases, since no root system has assumed
dominancy in extension, these trees should be
planted undisturbed, in the hope that some of
these points will assume dominancy in the field to
grow and extend into structural laterals.
To enable the trees to develop as soon as possible,
fertilizers should be applied soon after
planting. In areas where phosphate is a problem,
about 1 pound of rock phospha te can be placed at
the bottom of the tree hole or superphosphate can
be sprinkled among the roots. Slow-release ferti­
1izers in tablets or granules may also be applied.
Where lack of water can become a problem,
irrigation water should be available; if it is not,
the trees should be planted only when rai nfall is
expected. In planting the trees on lava land at
45