These results demonstrate that by using a hitch sensor,
a single RTK-GPS system mounted on the tractor can perform
as well as systems where a separate RTK-GPS system was
mounted on the planter. The tomato plant RMS location
accuracy in the direction transverse (East/West) to the direction
of travel was slightly lower (10%, which was significantly
different from zero at a ¼ 0.05 according to the ANOVA) than
the RMS accuracy longitudinal (North/South) to the driving
direction. This is in contrast to the results by, Ehsani et al.
(2004), Nørremark et al. (2007), and Sun et al. (2010) where
increased error in the along-track direction was observed and
attributed to due to dynamic effects during planting.
This difference may be partially due to error in the hitch sensor
measurements since the geometry of the relative motion
between the tractor and the transplanter causes hitch position
errors to have a substantially greater impact on
transverse-track errors when compare to the effect on alongtrack
errors. This issue is discussed in greater detail when the
results of the second experiment are discussed, where the
heading deviations between the tractor and transplanter were
more severe.