Special crops require the use of special
tools to protect them against weeds left behind by cultivation, chemical
treatment, hand weeding, hand rogueing, hot capping or flaming, and other, less effective, applications and hand
weeding tools. The Ergonica Weed Twister
was designed to more efficiently penetrate the soil with a minimum of soil
disturbance and extract both new seedlings and deep roots of various shapes and sizes more precisely
and efficiently than other hand tools and weeders, including various hoes, weed
pullers, weed poppers and other weed twisters. As California, along with other states, is embarking on a new era in
agriculture when traditional methods of hand weeding are being reexamined and
new alternatives for precision weeding and the short hoe are being explored, a
greater emphasis on creative tool design is mandated. A tool, such
as the Weed Twister, which promises to provide powerful deep root extraction as
well as efficient precise hoeing and tilling, is causing much excitement in the agricultural
community.
Much of this excitement is the result of a legacy of conflicts between the
health of farm workers and the growers' demands for efficient and precise
weeding. After the short hoe was banned in 1978, farm workers were forced
to remove weeds by hand for many hours a day. Some would argue that this
was more damaging to the health of farm workers than the use of the short hoe. Recent litigation between the UFW, represented by CRLAF, and
California growers has climaxed in Cal OSHA regulations that not only prohibit
the use of the short hoe but also severely restrict the use of hand weeding.
Machines are working, but people
are broken!
One of the latest developments for
mechanized hand weeding is a controversial human-hybrid weeding machine which
supports several workers prostrate on their abdomens and allows them to pull
weeds by their hands, literally laying down on the job! This practice was
recently described as inhumane in a Southern California periodical
La Opinión. The article from Lamont, California, is
entitled El
Valle Central: pobreza que duele / The Central Valley: poverty that
hurts. One of the workers complained
that they finished work seeing stars, feeling sick to the stomach and
with the neck all in pain ("Terminamos viendo estrellitas, mareadas y
con el cuello todo adolorido"). Whether this is a sign of the
future, given that there is already a scarcity of farm workers
in California and other areas, remains
to be seen.
Is this the organic farming worst case scenario?
Hopefully, they won't further harness the workers' legs to
save gas and extract their bodily fluids to fertilize the soil in the
next generation of this human-hybrid weeding machine? These
flat bed weeders or
lay down weeders and bedweeders as they are called, are sometimes used for weeding
carrots and other vegetables often with the intent of reducing the
trauma caused by alternative methods as well as more efficiently getting
the job done. You get an intelligent beast of burden with good
hand-eye coordination for minimum wages, and you don't have to worry about his or her survival, because the
workers are sustained in poverty throughout the western hemisphere!
This overwhelming poverty yields a nearly endless supply of people of
Latin origin who will sacrifice their sweat and blood to feed hungry
children back home.
Robotic Suit for Farmers: Japanese
scientists at the Tokyo University of Agriculture and Technology in
early 2009 demonstrated a prototype wearable assistance machine equipped
with eight motors and 16 sensors. This
robot suit for farmers is designed to allow a farm worker to
lift heavy objects, pull weeds and reduce the heavy burden of
harvesting as the nation's farm industry faces an ageing, shrinking
workforce. The 25-kilogramme (55-pound) device is intended to
assist elderly farmers who need support for their leg muscles and joints
when they keep a crouching position or lift their arms high. The
researchers said they were looking to commercial use of the suit in two
to three years at an initial price ranging from 500,000 yen to one
million yen (about 5,000 to 10,000 dollars). That's a lot
of yen, and 55 pounds is a lot of weight for an ageing farmer or
itinerant farm worker, but it may be a good deal if they include a Turbo Weed Twister with a built-in
torque power supply in the final package! At least this outfit
supports an upright farmer, as opposed to the prostrate bedweeder design
shown above.
We believe the creative genius of the American farmer
and supporting industries can do better in
the 21st century. Efficiency is not always the bottom line! Unfortunately, the laws and regulations in California and other
states do not currently protect the workers against these types of
abuses.
Your own conscience may
determine the bottom line for you or your farm, organic or otherwise.Some
carrot growers in Colorado and elsewhere have found
flame weeding to be an effective and
ergonomic alternative, for example.
There are many other economic alternatives including very precise hand
weeders like the Ergonica Weed Twister as well as effective mulching and
other methods described below.
Human-hybrid Weeding Machine (Flat Bed Weeder - Bedweeder)
Ardua labor. Estas mujeres trabajan casi 10 horas
al día en condiciones infrahumanas. (Araceli Martínez/La Opinión)
Enforcement of safety
regulations in California agriculture has recently (2008) led to 28 inspections
on January 23 and 24 and the issuance of 26 violations totaling $12,750 in
penalties, as reported by the California
Department of Industrial Relations. Employers were cited for not paying
minimum wage, failing to provide sufficient meal and rest periods, inappropriate
operation of driverless tractors and operating tractors with defective seat
belts. Citations were also issued for failure to provide adequate tools
for hand weeding, not providing adequate toilets on site and having
drinking water too far away from work areas. These citations were issued
by the Economic and Employment Enforcement Coalition (EEEC) in Imperial and
Riverside counties. The EEEC, now established as the Labor Enforcement Task Force (LETF), is a multi-agency task force designed to root
out California’s underground economy by enforcing California labor laws, and
educating business owners and workers about those laws and regulations in
workshops held regularly statewide.
The Coachella
Valley Farmworkers Survey (www.iurd.org) interviewed 525 farm workers in
2006, reporting that 54 percent were legal immigrants, 37 percent unauthorized,
and nine percent US citizens. About 71 percent do not speak English, and 72
percent live in the area year round, although 58 percent reported going to
Mexico for medical care.
Clearly, the organic farming industry does not need to be labeled as
anti-herbicide and pro-homicide, given that their consumers are likely
very conscientious! The organic standard is an important
contribution to higher quality and safer foods. Perhaps, there
also needs to be an additional voluntary 'labor kind' standard
for farms and employers defined by the way they treat their workers, a
standard that goes beyond the minimal labor codes and includes
consideration for the feelings, pains and remuneration of workers?
Studies in some parts of the world such as Africa, for example, have documented
a cultural preference for short-handled hoes despite the resulting
discomfort and health hazards for female workers.
Sustainable agriculture should also mean sustaining the health, prosperity
and human dignity of every hand that touches our food. The tools employers
choose or don't choose can either empower or enslave our human resources. A
number of other weeding machines images are presented by the European Weed Research Society
including the rotary hoe, flexible chain harrow, spring tine harrow, Lilliston
rotary weeder, horizontal-axis brush hoe, vertical-axis brush hoe, compressed
air and brushes, finger weeder and torsion weeders. None of these machines
is based on human sacrifice.
Three new cultivation tools were recently compared
(year 2007) with a traditional between-row cultivator, an herbicide control, and
the conventional herbicide-plus-cultivator weed management program used in a
first-year strawberry (Fragaria xananassa) planting. The new implements were (1)
a Rabe Werk flex-tine harrow, (2) a Buddingh finger weeder, and (3) a Bärtschi
brush hoe. This study showed an improvement in productivity when
using certain cultivators for situations in which labor is scarce. Organic
growers, and growers who plant in nontraditional annual systems, may benefit
from their use as well. An abstract of this study was published in HortTechnology 17: 9-141 (2007)under the title Cultivation Tools to Reduce Hand Hoeing in Matted-Row Strawberries,
with authors Mary Jo Kelly, Marvin P. Pritts and Robin R. Bellinder, Department
of Horticulture, Cornell University, Ithaca, NY 14853. This study,
unfortunately, did not endeavor to compare the efficiency of various hand hoeing
tools for this application. Such a comparison in scientific measures would
be most useful to farmers of various vegetable crops as well as to the organic
farming industry in general.
Can classical music help to control weeds and pests?
The green revolution may have outlived its initial impetus but the music
revolution may be the next big thing in agricultural innovation. For two
brothers in Punjab playing music to their crops has produced a bumper harvest
and with fertilizers and pesticides wrecking havoc on the soil this might be a
viable and entertaining alternative. These two brothers of Sangrur
district in Punjab, for the last 2 years have not used any pesticide for their
crop grown on a 6-acre land. Instead, they decided to treat their crop to
a dose of music. They claim the yield has gone up by 5 per cent but more
importantly the quality has been phenomenally well. This remarkable
innovation was reported by
NDTV.COM in January, 2008, which you can see and hear in this video clip.
Unfortunately, the article doesn't tell us whether Mozart, Chopin or Bach was more
effective, but it argues that music can replace pesticides. Perhaps the pests
here prefer rock-n-roll?
Beyond the legal, moral and health issues, the ongoing needs for
better efficiency and sustainable agriculture energize the movement for
technical advances. Because of its power and precision, as well as an
ergonomic, light-weight design, the unique Ergonica Weed Twister is being
regarded by many experts as an essential tool for every farm and garden where
exceptional care is a must. Although hand weeding has long been considered
the most precise manner of protecting crops, Ergonica presents a challenge to a
higher level of surgical precision by using a tool that more effectively removes weeds that are
often left behind by hand weeding methods. Whether weeding strawberries
or other cash crops,
removing volunteer potatoes or stubborn mallow weeds, or harvesting truffles worth over $100 per pound or
$300 per ounce at some consumer markets,
surgical precision in an efficient and ergonomic framework is an ideal standard that the farming
industry should ultimately expect.
Weeding and propagating are
essentially the two principal arts of agriculture:
Unless you grow crops in the desert or in
artificial platforms, before you plant or germinate your crop, you must clear
the existing vegetation, whether it is native or introduced. Thus, agriculture
may be seen as the art of nurturing and separating preferred plants in a
selected area from the undesired plants that thereby become identified as
'weeds'. The designated weeds may be relatively useless plants or sometimes,
unfortunately, native flora and forests of value to other parties and species as
well as to the regional ecology. Effective separation and selective nurturing
become critical due to the economies of space, time and resources.
In this setting, the
creative leaders of the agricultural industry are invited to
design and implement new methods, tools and technologies to
solve perhaps one of the oldest problems in the civilized
world. We are focusing our attention in this paper on the
design of hand tools that offer more precision than the
tractor-driven cultivators and mechanical weeding devices available today.
To be comprehensive in our perspective,
we should not rule out the possibility that in the future there
may be new tractor-driven mechanical weeders with more precision
than those available today. Herbicides are also widely and
effectively used in agriculture. Flaming (hot capping) with a
propane torch is widely used on young organic crops and other
crops in appropriate circumstances. Yet, with the best of our
chemicals, flaming techniques, tractor-driven tools and
integrated weed management, our industry in California and
elsewhere is still beset with the demand for additional
applications of more precise weeding for at least a few crops.
The precise weeding crops in California
include commodities like celery, cabbage, lettuce, broccoli,
spinach, carrots and strawberries, for example. Some nursery
crops also require hand-weeding. For some of these crops,
California grows as much as half or more of the total national
production. Growers do not like to hand weed because of its
cost. Some growers cite the costs of hand weeding to be 2 to 10
times more per acre than other types of weed-control practices.
Growers indicate that some of the crops or conditions that may
require hand weeding or thinning include:
In the fields of Oxnard, California, the
Weed Twister removes mallow in this scene of a preliminary
demonstration.
Conditions Requiring Hand Weeding or Thinning
1. Hard to see weeds because of dense
crop and/or plant cover. (cabbage)
2. Little spacing between plants. (carrots, onions, leeks, garlic)
3. Must remove weeds (and any damaged plants) from plant bed before
harvesting. (spring mix, lettuce, parsley)
4. Weeds growing immediately next to plants.
5. Removing doubles.
6. Nursery plants in containers.
7. Weeds under organic grapes on steep hillsides.
8. Various plants grown for seed.
9. Use of drip tape.
10. Use of plastic mulch or woven cloth.
11. Use of netting to support flowers.
12. Use of long-handled hoe might not kill the weed.
13. Use of long-handled hoe can be cumbersome when one hand is required to
carry a bag to dispose of weeds, move aside large leaves, or gather the
harvested plants.
Hand Weeding Farm Lab - Davis, California
Recent tests of the Weed Twister vs. mallow and other late season
weeds at UC Davis in California.
Dr. Tom Lanini,
Weed Ecologist, is shown smiling with a large mallow grasped by the Weed
Twister in bottom right photo.
According to a study by P. W. Owston and L.
P. Abrahamson hand weeding has been the mainstay of forest -nursery
weed-control programs. Amounts reported vary from 1 to 80 person-hours per
acre over an entire season, the variation resulting from differences in weed
populations, management philosophies, and other practices.
The need for precise weeding in agriculture is as old as
the history of agriculture itself. What is new in California, is the greater interest in
this society for the protection of the health and safety of farm workers.
The trend of increasing organic farming also demands alternatives to harmful
chemicals often resulting in hand-weeding and the use of precise hand tools.
The Weed Twister and other hand tools of
its class that we will examine and compare in this paper, are all fairly simple
in design, have few, if any, moving parts, and, for the most part, are not motorized,
except for the new drill-ready Turbo Weed Twister. With all
the technology available in California, often housed in the same valleys which
nurture our bountiful crops, we are not yet at the point where we are discussing
more sophisticated tools. A classification and comparison of other hand
tools used primarily in home gardens is presented on the Weeder Features page.
Perhaps the new regulations may spur the imagination of
California's
technology leaders to invent the laser weeder, for example.
Imagine a light weight laser wand that can exterminate any
weed of any size and shape with a lightning-quick zap?
Could the next evolution be the robo weeder? Visualize the robotic rover
automatically weaving through the fields and deftly taking out each enemy
by intelligently making the identity and status of every growing thing in its path.
Recent advances in online graphic object recognition, such as the work being
done by Microsoft,
may eventually lead to uploading images of plants by cell phone and receiving a
species identification search response.
Robotic Cultivator System
Sometime within the next few years,
though, there may be a new mechanized weeding system available to growers, which
will save them hundreds of dollars per acre. Over the past three years, David
Slaughter, a researcher at the University of California-Davis, has been
working on perfecting a
precision weed control
robotic cultivator system that can tell the
difference between weed seedlings and tomato seedlings in the field. On
the back of the mechanism, there would be several mounted miniature hooded
sprayers that would go in between the rows and spot spray the weeds, leaving the
tomato plants and everything else in the field untouched.
Machine vision based detection of volunteer potatoes in cropped fields
is also being studied by the Wageningen University, a Dutch university in
Europe, which claims to be the leading European university
in the Life Sciences. The Hortibot
is another design in development in by Rasmus Jørgensen in Denmark that may use
mechanical means to remove weeds as well as chemical sprays.
No Chemicals Needed!
More recently (2015) the same UC Davis team has devloped a faster way to identify weeds
in beds mixed with crop seedlings that can be singled out and removed deftly with knives.
No chemicals needed! Slaughter?s team is designing a robotic cultivator that can remove
weeds in commercial fields as carefully as gardeners pull weeds in their own backyard,
without the time-consuming labor and cost. They?re developing a ?smart? cultivator with
small knives that reach out to uproot weeds and retract to keep crops intact. This will
be especially useful in wide beds of densely seeded crops like spinach and baby lettuce,
which can turn green almost overnight with weeds and leafy crops.
The key technology to facilitate this is to make the crop seedlings glow with a faint, fluorescent
color. Glowing plants are protected by the robotic identification system. The fluorescent glow
is accomplished by a simple seed coating. Seeds are commonly coated with various materials (like
fertilizers, fungicides or herbicides) for different reasons. No biotechnology or any genetic
engineering is involved. The USDA is investing $2.7 million in the new cultivator design, which
will take shape over the next five years. More information.
A solar-powered robot with 20/20 vision, on a
search-and-destroy quest for weeds, will soon be moving up and down the
crop rows at the experimental fields at the University
of Illinois. What's more, this robot has the potential to
control weeds while significantly reducing herbicide use. The
robot uses GPS for navigation, and there are two small cameras mounted
on a frame on top of the machine to give the robot depth perception,
just like a human, according to Lei Tian,
agricultural engineer at the U of I. "If he sees a weed, he can actually
tell how far away it is." An on-board computer offers access to
information that provides the morphological features of plants, to help
the robot determine just what is and isn't a weed. Once a weed is
identified, a robotic arm attached to the front of the machine engages a
device the researcher calls "a custom-designed end effector."
Using similar image analysis techniques to those used on the Robocrop
2 high speed hoes, Robocrop InRow analyses images of the crop
immediately in front of the weeder. Applying a predetermined grid and
best fit logical deduction techniques individual plants are pinpointed
and tracked through the image. The weeding rotors are then synchronised
to work around each individual plant, the rotor speed being continually
adjusted to take into account plant spacing variations. The InRow rotors
are then followed up by a set of inter-row cultivation units to complete
the all round cultivation process.
Performance is 2 plants per second per row.
We acknowledge that new technology is
often a
double edged sword. New jobs are created and old jobs are eliminated.
More efficiency usually means lower cost and less people on the payroll.
Politics and legal conflict have brought us to the historical point where
we are today examining new and old methods of precisely removing weeds.
The grower will benefit by better tools and methods of precise weed removal
regardless of the political context of the day. More efficient and
ergonomic tools
will be of value to both growers and
laborers whether
or not traditional methods are restricted by society.
ERGONICA WEED TWISTER
Although we're not talking about the robo weeder
or the laser weeder here, the patented double helix design of the Ergonica Weed Twister is an advanced
state of the art of probing and pulling out weeds by the roots in a precise and
efficient manner. Its pointed double coils are designed to
efficiently penetrate the soil and can be used to screw deeply into the root
structure of the weed. The coils can also be applied as a circle-shaped
hoe, gliding along a shallow path beneath the surface of the soil to unearth new
weeds and seedlings with very short root structures. Both the deep root
extracting and the shallow depth hoeing applications of the Weed Twister are of
special importance to precise weeding in the agricultural setting. We will
examine these and other features more analytically in comparison to competing
designs below.
Organic Growers may Use this
tool as an alternative to hand weeding when crops are closely spaced and extra
precision and care is required. Works great for both new seedlings and
deep-rooted weeds in various situations including around the edges of plastic
mulch. View this new lineup of Weed Twister models as an alternative to
short-handled tools and knives that often injure workers and increase labor
costs.
Several Weed Twister features have
ergonomic value. The name of the manufacturer, Ergonica, was derived from
"Ergonomic America." The standard model is 36 inches in length and weighs
about one pound. This design has been in production and distribution
through internet marketing in the United States for several years.
Although it has never been distributed through normal retail channels, the Weed
Twister has thousands of happy customers who often come back and buy extra Weed
Twisters as gifts for their friends. A few nursery stores in southern
California also carry the original 36-inch Weed Twister model.
In the agricultural setting, a longer
handle prototype has been designed for testing and development and is now
available for online purchase. We have recently tested a 42-inch and 48-inch Weed Twister model in several farms in Oxnard
and Davis, California,
where we successfully removed such weeds as little mallow, goosefoot, yellow nutsedge, purslane, nightshades and lambsquarters. These were
preliminary tests aided by the UC Cooperative Extension and limited in scope
with the intent of evaluating the general applicability of this tool in
agriculture and to compare the ergonomics of the various Weed Twister models.
These initial agricultural tests have also led to refinements in the
design of the tool including the sharpening of the thicker coiled tines, the
optional 8-inch T-handle expansion kit, and the addition of the bar grip in the
54-inch model for increased torque strength and speed when twisting into deep
roots in clay soil. More recently the options have expanded to include a 60-inch model
for added reach and ergonomic comfort especially for taller workers and others
working from a wheelchair.
In the spring of 2007, additional tests have
been initiated by weed scientists in several states using different Weed
Twister models, including the hefty 54-inch Dual Grip model.
Several tests in the United States and Japan have also been focused on
using the Weed Twister to remove volunteer potatoes. A Japan distributor
has found an eager market for the Weed Twister to clear potato fields in Sapporo, Japan between seasons.
Remaining potatoes after harvest are removed with the Weed Twister in order to help prevent
potato blight.
In this case the Weed Twister helps to "fish" for any small tubers remaining in the ground
which may possibly be infected with the fungus (Phytophthora infestans) that causes blight.
In April 2008, the TurboTorx
36 Weed Twister model was made available to provide the
convenience of drill-powered speed to clear small and large weeds by
their roots with a 36-inch shaft. This model appears to be a
favored approach to economically thin large areas of weeds with a
minimum of labor and yet high precision, like all other Weed Twister
models. The newest 42-inch Turbo Weed Twister is the longest-handle
electric weed auger on the market.
The
Turbo Weed Twister represents a new
level of technology for drill-powered weeding tools due to the
engineering of the unique sleeve grip and other advances which allow for
a longer shaft without compromising precision and ergonomic safety.
This enhances the Ergonica Weed Twister line of weeding tools from a
manual operation to a semi-automated solution to weeds, small and large,
left behind by herbicides and other mechanical processes. Should
this be the arm of the ultimate weeder robot?
We invite the agricultural
community to help us test these models of the Weed Twister with other
crops and weeds in comparison with other methods and tools of interest.
Students in agricultural programs in California may ask their
instructors if they can participate in some of these tests as a part of
their studies or science projects. Other science project suggestions are listed
on the Science Projects page.
Noxious weeds such as the sow thistle, recently discovered in
Santa Barbara County vegetable fields for the first time, may also be good targets for testing the Weed Twister. Lists of
noxious weeds for California and other states including images of each weed are
identified and linked on this site on the Weed
Identification pages.
A new level of technology
for drill-powered weeding tools!
Save the Farm from excessive labor
overhead!
While fully automated robotic weeding
machines are still in the development and testing phases, it appears that a
semi-automated solution, such as a drill-powered device may provide relief to
weed pressure without excessive labor costs. Perhaps a robotic
device may be hooked up with a Turbo Weed Twister instead of a jet of chemicals?
What it takes is possibly looking outside the box of chemicals, as productive as
they have been in the recent decades, and looking for quicker and more efficient
plant removing mechanical tools controlled by robotic weed detection and
guidance systems. Progress in this direction is noted by the
Bosch Bonirob Robot
that punches small weeds into the ground with a small rod as shown in this
video. No chemicals needed!
Of course, for larger late-season weeds, you'll need to hook up a Weed Twister to your Bonirob
to twist out those misplaced plants, especially in organic certified farms!
CLASSIFICATION STANDARDS
To meaningfully compare competitive tools
and technologies we need to determine the definitions of the applicable classes.
We offer the definitions of the classes we have used as examples to use for
reference only. If needed, we expect the industries involved as well as
the appropriate regulating bodies will more
formally establish appropriate standards.
Ergonomic - Long Handle
The Ergonomic handle has a length of at
least 30 inches. This is also known as the Long Handle and the Back-Saving
Handle. The standard model of the Weed Twister, with a length of 36
inches, fits into this standard. A number of other weeders listed on
this website also comply with this standard. A sub-class of this with a length of at
least 45 inches is the Extra Long Handle or Industrial Length Handle. The 48-inch
and 54-inch Industrial Weed
Twister models fit into this class. The Full Length Handle has a length of at
least 60 inches.
It should be noted that current
Cal OSHSB regulations define long-handled tools as those with handles at
least 48 inches in length. The latest regulations restrict the use of either
long-handled or short-handled weeding tools from a stooped, kneeling or
squatting position. The 48-inch Weed Twister model and the 54-inch
Dual Grip Weed Twister model would both be acceptable for agricultural use in
California.
Hand
weeding may be acceptable under the new regulations in
situations where it is proven to be the only practical way to effectively remove weeds
without damaging crops.
Light Weight
We define a Light Weight hand weeder as a
tool with a weight of 2 pounds or less. A sub-class of this standard would
be the Very Light Weight standard with a weight of one pound or less. The
standard Weed Twister, with a weight of one pound, falls into the Very Light
Weight classification. The 48-inch Weed Twister weighs less than two
pounds and the 54-inch model with the added bar grip weights 3 pounds as does the
60-inch model. Several other long-handle weeders, such as those with a foot lever,
for example, weigh closer to 4 lbs or more. These standards are appropriate only for the
Long Handle tools as defined above.
Precision Weed Removal Tool
The measure of precision is inversely
related to the dimensions of the action point of the weed removal tool.
In other words, a 3-inch hoe blade is more precise than a 5-inch hoe blade.
We have used a maximum of 3 inches in width to determine the classification of a
tool as Precise. Most of the hand weeders that are claimed by their
manufacturers to be "precise" on the market today fit within the 3-inch
standard. We have extended this class to smaller dimensions by defining
the Very Precise class as a tool with an action point width of 2 inches or less.
The Extremely Precise tool has a dimension of one inch or less. The Weed
Twister standard model has a width of 2 inches in diameter and is thereby
classified as Very Precise.
Because of the forceful manner by which a hoe is
normally applied to the
target area, that is with a hammering or hacking motion, the effective precision
of this tool may be compromised. The hacking motion exposes to possible
damage anything in the path of the tool and handle as it is applied. With the
swift motion, it also
requires great accuracy to hit the target precisely and effectively. Every
hack increases the possibility of damage to nearby plants. This
increases the effective precision area for a 3-inch hoe blade to possibly 6
inches or more. Even the short hoe requires a relatively violent motion
compared with the Weed Twister and other precision tools on the market today.
Thus, a 3-inch hoe may effectively be not precise since its normal use
required by its design exposes to
damage an area greater than 3 inches.
STANDARD CLASSIFICATIONS AND ECONOMIC /
ERGONOMIC TRADE-OFFS
The standard Weed Twister is a Long
Handle, Very Light Weight, Very Precise hand weeder. When comparing it to
other tools, the comparisons should be made against other tools in the same
class. The agricultural models with 48 and 60 inch handles are in a
different class. These models are Extra Long Handle, Light Weight, Very
Precise hand weeders. The newest 60-inch model is also suitable for
wheelchair gardeners. If we expand the diameter of the coils of the
Weed Twister, we may change it from the Very Precise class to the Precise class.
The trade-offs are fairly straightforward.
The longer handle appears to have more ergonomic value since it requires less
bending of the back or stooping. The 48-inch length also makes it legally
acceptable for Cal OSHA standards for long-handled tools. The 60-inch
model weighs a pound more than the 48-inch model. In other words, the trade-off
is more weight for less back stress and compliance with Cal OSHA regulations.
We propose more tests in
agricultural settings with perhaps several lengths to determine the optimum
trade-off. There are actually two advantages to shorter Weed Twister lengths:
1) less weight, and 2) more efficient motion depending on the distance between
the worker's hands and the target weeds. We may also find that the optimum length may depend somewhat on
the height of the worker. In this case, we may offer the grower the option
to purchase a number of tools at different lengths, and allow each worker to
pick the tool he or she finds to be most comfortable and efficient for himself
or herself.
There may also be trade-offs in efficiency
when modifying a tool to be more precise. For example, a 3-inch hoe blade
may be less efficient than a 5-inch hoe blade because it takes more work to
cover a larger area. However, it may be less effective when 3-inch
precision is necessary to protect the crops. The need for precision is
the justification for using relatively inefficient tools. Depending on how
much precision is needed, relatively less efficient tools may be appropriately
selected. We would not be looking at hand tools at all, if the required
precision and care for all of our crops could be accomplished with tractor-driven
solutions or chemicals.
The grower needs to evaluate not only
if precise methods and hand tools are needed, but also what degree of
precision is needed and what cost is affordable to accomplish such precision?
