ROBOTIC WEED WARS:
NEW GAME,
NEW PLAYERS,
NEW RULES
STEVE FENNIMORE,
UNIVERSITY OF CALIFORNIA, DAVIS
INTRODUCTION
❖Agricultural labor costs are rising
❖Specialty crops are very labor
intensive and need greater automation
❖Weed control costs are much higher in
vegetable crops than in agronomic
crops
❖Weed automation is needed in both
agronomic and specialty crops
Lettuce must look perfect or it is not harvested
Weed Management Practices & Costs 2015*
Practice
Romaine Hearts
($/acre)
Organic Spinach
($/acre)
Herbicide application
51
0
Mechanical cultivation
46
39
Hand weeding
153
440
Total weed mgt cost
250
479
* Source: UC Cooperative Extension Cost and Return Studies. http://coststudies.ucdavis.edu.
Costs per acre include materials, equipment, and labor ($16.10/hr. field; $21.70/hr. machine).
COMPARISON COSTS FIELD CORN
❖Field corn production labor cost/A $36
❖Field corn weed control cost/A $32
Iowa State
University 2017
Projection of weed management costs
with increase in minimum wage - example*
2015
2022
Difference
Field labor ($/hour)†
11.50
15.00
Labor cost ($/acre) –
romaine hearts
185
241
$ 56.00
Labor cost ($/acre) –
organic spinach
461
599
$ 138.00
$
3.50
* Exercise projecting 30% increase for field labor and similar increase
for machine labor, using 2015 UC Cooperative Extension Cost and Return
Studies http://coststudies.ucdavis.edu.
† Hourly wage figures do not include a benefits package.
Hand weeding
❖ Practiced
for decades in specialty crops
❖ Necessary due to few herbicides for
flower, herb and vegetable crops
❖ Labor shortages and high labor costs
mean that hand weeding is not
sustainable for the long-term
Herbicides
main lettuce herbicide – pronamide
was registered in 1972
❖ Discovery, development and marketing
of new herbicides is ~$286 million &
takes 11 years – discovery to market
❖ Few new products
❖ The
DEVELOPMENT COSTS:
HERBICIDES VS. AUTOMATION
Total costs million ($)
350
300
$286 million
250
200
150
100
50
0
$12 million
Herbicide
McDougall 2016
Automation
Polsen DK, Mol NL 2016
WEED MANAGEMENT IN VEGETABLE CROPS
BlueRiver
Hand Hoeing Weeds in Tomato
Hand Thinning & Hoeing Weeds in Lettuc
Mantis Ag Tech
Hand Weeding
in Organic
Lettuce
Poulsen
Steketee
Weedy Lettuce Field
BEFORE THINNING
AFTER THINNING
BLUE RIVER THINNER ON 80 INCH BEDS
Salinas, CA 6.19.15
LETTUCE THINNING- INTERMITTENT
SPRAYERS
Saved
plants
Saved
plants
Sprayed zone
Sprayed zone
Time minutes/A
LETTUCE THINNING
AUTOMATIC VS. HAND
550
500
450
400
350
300
250
200
150
100
50
0
12 min/A
Automatic
480 min/A
Hand
Jim Ostrowski, BlueRiver
LETTUCE THINNING
❖Automatic thinning has been accepted and integrated into
industry – uses much less labor
❖Requires a product to selectively spray to kill undesired
lettuce – eg. carfentrazone
INTELLIGENT CULTIVATORS
❖These cultivators sense the crop with pattern recognition using
machine vision
❖Cultivator knives move in and out of plant row – “robotic hoeing”
INTELLIGENT CULTIVATOR (IC)
THE ROBOVATOR
Computer
Static
knife
Light
Camera
Mobile
knifes
speed sensor
ROBOVATOR ON 80 INCH
BEDS
EFFECT OF CULTIVATOR ON WEED
CONTROL AND WEEDING TIME
Weed control
Cultivator
2014-L
2015-B
Control (%)
Hand weed time
2014-L
2015-B
Hours Acre-1
Standard
57 b
35 b
38 a
24 a
Robovator
84 a
74 a
27 b
13 b
+27%
+39%
-29%
-46%
Difference %
1. AUTOMATION – ROLE FOR
PUBLIC SECTOR
❖ Train students in multiple disciplines
needed for weed control automation
❖ technology, engineering, weed science
❖ Research needed for high-risk high-gain
technologies
❖
❖
❖
❖
Lasers
Abrasives (sand blasting)
Thermal methods (hot oil, serial flaming)
Crop/weed identification
2. AUTOMATION – ROLE FOR
PUBLIC SECTOR
❖ Joint ventures between industry and
public sector will create opportunities
❖ Create new companies and jobs
❖ Student internships and real world
mentoring
❖ Ensure that students are being trained
with skills relevant for a workplace with
continuously changing technology
ABRASION
Preliminary Hot Oil Tests
u
Before
Heated Canola oil “Sprayed”
on top leaves.
Just After
Temperature (oF)
82 201 302 351
Mortality 2 weeks 0
post treatment (%)
20
90
√
91
√
Giles & Slaughter
24h After
LASER
FRANK POULSEN –
PRECISION FLAMING
CONCERNS
❖ Private funding will not be adequate to
serve needs of the industry as a whole
❖ Public good vs. private good
❖ Intellectual property protection
❖ Machines are harder to protect
❖ Lack of coordination and standardization
❖ Will it be assumed that this technology is
only relevant to specialty crops?
AUTONOMOUS VEHICLES
Ecorobotix - Swiss
OPPORTUNITIES
❖ Create a new cutting edge industry with high
paying jobs
❖ Develop low risk methods of weed control not
dependent on herbicides
❖ Develop sustainable integrated weed management
systems less likely to develop herbicide
resistance
❖ Develop new weed control tools for vegetable
crops both conventional and organic
❖ Weed control devices are much more flexible than
herbicides and can take advantage of new
technologies as they develop
SUMMARY
❖Automation of weed removal creates
new tools to sustainably manage weeds
with less dependence on herbicides
❖There is need for public investment in
this technology if the US wants to take a
leadership role and develop a high value
industry that creates good jobs, and
ensures a safe and reliable supply of
fresh produce