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

Figure 84. Leaf stripper showing the counter-rotating scrolls to separate the nuts from the leaves.
pebbles. On lava land this method created cavities
throughout the harvest areas. To compound the
problem, the pebbles and fines that were picked
up and dropped from the machine in mounds
needed to be placed under the trees again. Considerable
work on vacuum harvesting needs to be
done before this method can be used on macadamia
nuts.
Net harvesting (Fig. 83) has been tried in orchards
where the terrain was too difficult and
costly to improve to permit sweep harvesting (59).
In this method Yl-inch polypropylene net was
stretch-suspended on wires nailed to limbs of trees
in a "V" design under the total canopy of trees. At
gathering time, the flaps at the bottom of the "V"
were opened, and the nuts, leaves, and small twigs
were dropped on polyethylene sheeting to be lifted
onto a leaf stripper (Fig. 84). The nuts were then
dumped into a trailer bin to be hauled to the
husking station. This system of harvesting was
abandoned because of the high initial cost of
netting and the high cost of maintaining the nets
damaged by large-branch breakage.
Husking
The in-husk harvested nuts are transported to a
husking station by various means. Small farmers
usually use bags for storage and hauling; large
growers use bottom-dump trailers (Fig. 85). The
fleshy husk on the nuts as received from the fields
needs to be stripped and removed as soon as pas-
sible to minimize loss in nut quality. Husking is
usually done at a centralized station. The accumulated
loose husks are then disposed of by whatever
manner the grower chooses. They can be used for
composting in nursery operations or as an organic
material source for anthurium culture.
The principles and methods of husking currently
used were developed in earlier years when
the economic potential of the macadamia nut was
first recognized. The first attempt, obviously, was
by hand; this evolved into a crude system of using
a rubber-tire-section doormat to hold the nuts
steady and a hammer to break and tear the husk.
The next innovation was the use ofa spinning rear
tire of a jacked-up car formfitted into a metal
abrading plate (Fig. 86). In this method, the nuts
were dropped into the trough created by the
abrading plate and the spinning tire, and husked
by the forces thus created-much akin to pebbles
being strewn off the road by a rapidly turning tire
on a car. With the continued growth of the industry,
the jacked-up-tire husker was further improved
as a permanent stationary system using
electricity. One small grower still uses this system
and has used the same tire for the last 25 years (Fig.
87). Another husker now popular is based on
counter-rotating scrolls (Fig. 88). Although this
method has been patented, the true credit for its
invention is obscure.
A new husking machine (Fig. 89) has been
invented by Quentin F. Gandall of Hilo and is
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