PCC July-August 2020

Continued from Page 16
marketable fruit yields in the IC and
standard cultivator treatments of 44,045
and 50,217 lbs./A, respectively (P>0.05).
Similarly, there were no differences
between the cultivators in their effect on
lettuce yields (P>0.05) (Table 1). Yield
data were analyzed both as the number
of marketable lettuce heads per acre and
fresh weights.
Weed/Crop Differentiation. One of
the biggest challenges for automated
intra-row cultivation is to enable a computer
and vision system to differentiate
between crops and weeds at normal field
travel speeds. The commercially available
IC ‘Robovator®’ uses pattern recognition
to recognize the crop row and can
perform intra-row weeding at speeds of
1 mph (Lati et al. 2016). However, this requires
a distinct crop pattern best found
such as in a transplanted field where
the crop is much larger than the weeds
and the crop stand is consistent. Further,
when high weed densities obscure the
2-dimensional crop row pattern, the intra-row
weeding program does not work.
Two types of crop signals were tested,
Solutions for the Earth
physical plant labels and topical markers.
The methods have very low false positive
error rates and the classification accuracy
achieved for both techniques approaches
100%. The crop signaling technique appears
to be effective in creating a reliable
method for automatic detection of crop
plants in vegetable fields with high weed
densities. Crop signaling technology
could facilitate development of automated
weed control robots that are as
accurate in crop/weed differentiation as
human workers are.
A recommendation for future work is to
develop a commercially viable marking
method that is machine readable, yet
does not contaminate harvested produce
or the field soil and subsequent rotational
crops. For transplanted stem crops like
tomato, a biodegradable machine-readable
tag attached to each stem as the
transplanter sets the plants should be
explored for commercial potential.
Lettuce will probably require a machine-readable
label attached to the first
true leaves or a machine-readable label
on the fiber-coated plant plug as it is set
in the soil as is done with the Plant Tape®
(www.planttape.com) system of vegetable
transplanting.
DON’T FORGET THE SEASOL...
Increases Nutrient Uptake Efficiency
Increases Yield for a Bountiful Crop
Decreases Saline Stress
Improves Environment for Soil
Microbial Activity
Conventional and Organic Products Available
View the Full Study at
earthsol.ag/crops
Regardless of the technology used for
crop weed differentiation, development
of intelligent weed removal technology
has improved weed control programs for
horticultural crops that continue to rely
on a limited number of herbicides and
hand weeding. However, there is much
more to do to improve vegetable weed
control.
Acknowledgments. Thanks to the
USDA Institute of Food and Agriculture
Specialty Crop Research Initiative (US-
DA-NIFA-SCRI-004530), the California
Tomato Research Institute and the California
Leafy Greens Research Program
for financial support.
References
Lati, R.N., M.C. Siemens, J.S. Rachuy, and S.A.
Fennimore. 2016. Intra-row Weed Removal in
Broccoli and Transplanted Lettuce with an Intelligent
Cultivator. Weed Technology 30:655-663
WATER
SEASOL
www.earthsol.ag
Comments about this article? We want
to hear from you. Feel free to email us at
article@jcsmarketinginc.com
18 Progressive Crop Consultant July / August 2020