Agriculture Reference
In-Depth Information
(a)
(b)
(c)
(d)
FIGURE 7.15
(a) Trunk shaker system, (b) tractor drawn canopy shaker, (c and d) pair of
citrus canopy shakers with catch systems. (From Futch, S.H. et al.,
Horticultural Sciences
Fact Sheet HS-1017 4p
, EDIS Publication, HS218, 2005. With permission.)
contamination that can come from contact with fecal matter. The last and most suc-
cessful approach (although most expensive) required a mirrored set of self-propelled
shakers equipped with a catch frame. These systems (Figure 7.15c) had excellent
throughput and relatively high harvesting efficiency at 95%, whereas catch rates
were down to 85% (Futch and Roka, 2005b; Futch et al., 2005).
Similar to the approach used in citrus, mechanical shaking was used to mechani-
cally harvest apricots for processing. Torregrosa et al. (2006) evaluated five mechan-
ical harvesting systems for apricots, concluding that vibrational harvesting was
suitable for harvesting processed apricots, however, unacceptable for fresh market.
Although most of the mechanical harvesters developed were for processing, some
researchers developed harvesting systems for the fresh market. Peterson et al. (2003)
developed a two-unit mechanical harvester for sweet cherries (Figure 7.16). It used a
rapid displacement actuator to effect fruit removal and cushioned catching conveyors
to intercept falling fruits with minimal damage. Harvesting efficiency of 90% was
obtained from the harvesting tests, and the authors suggested that proper tree train-
ing could improve the efficiency. They also used a fruit removal enhancer (ethrel) to
reduce fruit removal force.
The same rapid displacement actuator was used by Peterson and Bennedsen
(2005) to remove apple fruits that were grown on narrow inclined trellises. The
actuator was manually positioned using a joystick to effect fruit removal, and an
energy-absorbing surface caught the falling fruits. Results showed that 53% to 73%
of apples were damage-free and showed better performance compared to a shake-
and-catch method.
