Macadamia Nuts in Hawaii: History and Production - ctahr ...
Macadamia Nuts in Hawaii: History and Production - ctahr ...
Macadamia Nuts in Hawaii: History and Production - ctahr ...
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Figure 81. Shake harvester with catchment frames on two separate units work<strong>in</strong>g together.<br />
Many types of harvest<strong>in</strong>g mach<strong>in</strong>es presently<br />
on the market can be adapted to macadamia nuts.<br />
However, <strong>in</strong> the use of this method on lava l<strong>and</strong>,<br />
the orchard floor terra<strong>in</strong> must be improved with<br />
fill materials (e.g., s<strong>and</strong>, quarry waste), mak<strong>in</strong>g the<br />
surface crevice-free to enable easier <strong>and</strong> more efficient<br />
pickup of nuts. On a better type of soil, such<br />
treatment is not necessary. The area under the<br />
tree must also be kept free of weeds <strong>and</strong> leaves so<br />
the nuts are not lost.<br />
Prior to harvest<strong>in</strong>g, small growers remove leaves<br />
under the tree by blow<strong>in</strong>g with a knapsack-type<br />
blower. The leaves are easily separated from the<br />
nuts <strong>in</strong> blow<strong>in</strong>g s<strong>in</strong>ce their light weight <strong>and</strong> flat<br />
shape enable them to be blown further away. The<br />
nuts thus exposed can be picked up by h<strong>and</strong>.<br />
Leaves can also be elim<strong>in</strong>ated <strong>in</strong> the orchard by<br />
burn<strong>in</strong>g them <strong>in</strong> open areas among the trees, by<br />
shredd<strong>in</strong>g <strong>and</strong> us<strong>in</strong>g them for mulch, or by bal<strong>in</strong>g<br />
them for use as a biomass energy source.<br />
Tree harvest<strong>in</strong>g us<strong>in</strong>g vibratory mach<strong>in</strong>es is<br />
be<strong>in</strong>g done by two large growers. One grower uses<br />
a unit with two self-propelled mach<strong>in</strong>es with catchment<br />
frames mounted on each unit <strong>and</strong> a grabshaker<br />
on one (Fig. 81). This harvester has a shaker<br />
clamp that hydraulically grips the tree trunk about<br />
2 feet above the ground <strong>and</strong> vibrates the tree for a<br />
few seconds to shake the nuts onto its deflectors<br />
<strong>and</strong> the catchment frame. The nuts are then conveyed<br />
to a b<strong>in</strong>. When filled, each b<strong>in</strong> is removed by<br />
a high-lift tractor <strong>and</strong> replaced by an empty b<strong>in</strong>. A<br />
shaker with its own catchment frame is now be<strong>in</strong>g<br />
used with <strong>in</strong>creased efficiency (Fig. 82).<br />
Although tree harvest<strong>in</strong>g has def<strong>in</strong>ite advantages,<br />
the effects of this method on nut maturity (7),<br />
quality, <strong>and</strong> yield (47) for all the cultivars now<br />
be<strong>in</strong>g used <strong>in</strong> <strong>in</strong>dustry have not been fully demonstrated.<br />
But labor availability <strong>and</strong> cost dictate<br />
the adoption <strong>and</strong> perfection of this method as soon<br />
as possible. Basically, the issue is whether the bus<strong>in</strong>ess<br />
loss is greater when harvestable nuts are lefL<br />
on the ground to become moldy or ea ten by ra ts<br />
prior to harvest, or when immature nuts are tree<br />
harvested, thus lower<strong>in</strong>g nut quality. These bus<strong>in</strong>ess<br />
alternatives may have to be decided on a<br />
plantation-by-plantation basis rather than an<br />
<strong>in</strong>dustrywide basis.<br />
Several other methods of harvest<strong>in</strong>g have been<br />
tried experimentally through the years but discarded<br />
because of some bad features <strong>in</strong> the methods.<br />
A modified golf ball picker with spr<strong>in</strong>g-loaded<br />
rollers about 2 feet <strong>in</strong> diameter was used <strong>and</strong> discarded<br />
because it was too flimsy <strong>in</strong> construction,<br />
<strong>and</strong> improvements appeared remote. A nut<br />
sweeper with many brush units operat<strong>in</strong>g on the<br />
ma<strong>in</strong> axis, so that each unit could follow its own<br />
l<strong>and</strong> terra<strong>in</strong>, worked well, but the project was<br />
ab<strong>and</strong>oned because of a drop <strong>in</strong> <strong>in</strong>terest. Harvest<strong>in</strong>g<br />
us<strong>in</strong>g the vacuum pr<strong>in</strong>ciple has not been<br />
too successful on aa lava l<strong>and</strong> s<strong>in</strong>ce the suction<br />
created by the mach<strong>in</strong>e picked up all materials on<br />
the ground, <strong>in</strong>clud<strong>in</strong>g nuts, smaller rocks, <strong>and</strong><br />
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