Agriculture Reference
In-Depth Information
harvesting method is similar to the way strawberries are harvested, where a pulling
or combing approach is used to detach the fruit (O'Brien et al., 1983).
7.3.4 B
USH
C
ROP
H
ARVESTING
Blueberries, grapes, blackberries, and coffee are some examples of bush crops. These
crops are relatively taller than surface crops. Unlike root crops and surface crops
where the harvestable fruit are located near the ground, the fruits of a bush crop
are randomly positioned in the bush. Over the years, different methods have been
proposed by researchers and growers to mechanically harvest these fruits. Some
of these approaches use combing devices, rollers, air blasting, electrical current
application, mechanical fingers to duplicate the human hand, high-speed shaking,
vibrating rods, and cutting devices. The most successful approach in bush crops uses
an oscillating mechanical shaker to detach the fruits from the bush (Brown, 1984).
Figure 7.12 shows a modern grape harvester, which is a self-propelled over-the-row
type of harvester. Two types of picking mechanisms can be used with this harvester.
One is the trunk shaker where the fruits are detached by vibrating the trunk. The
other is the cane shaker mechanism where the oscillating rods beat the fruiting canes
to effect fruit detachment.
The development of a successful harvester begins with investigating the plant/
fruit reaction to various modes of harvesting: (1) trunk shaker, (2) canopy shaker,
(3) selective harvester, (4) air blast, and (5) water blast, as well as other modes.
Once a successful harvesting mode has been identified, the designer can proceed to
develop the harvesting mechanism, catch system, material handling system, vehicle
platform, and power plant. Smith and Ramsay (1983) studied the process of fruit
Trunk shaker picking mechanism
Grape harvester
Cane shaker picking mechanism
FIGURE 7.12
Present-day grape harvester (American Grape Harvesters).
