CONTAINER-TO-CONTAINER TRANSPLANTING: OPERATIONS AND
EQUIPMENT
JOHN W. BARTOK JR.
John W. Bartok Jr. is Extension Professor Emeritus and Agricultural Engineer, Natural Resources
Management and Engineering Department, University of Connecticut, Storrs CT 06278-4087; email:
jbartok@rcn.com
Bartok Jr. J.W. 2003. Container-to-container transplanting: operations and equipment. In: Riley L.E.,
Dumroese R.K., Landis T.D., technical coordinators. National Proceedings: Forest and Conservation
Nursery Associations—2002. Ogden, UT: USDA Forest Service, Rocky Mountain Research Station.
Proceedings RMRS-P-28: 124–126. Available at: http://www.fcnanet.org/proceedings/2002/bartok2.pdf
Key Words
Workstation, transplanting conveyor, automatic transplanter, economics
Transplanting can be a large labor user in a tree
seedling nursery. Every effort should be made to
make it as efficient as possible.
Except for the small nursery with limited production
space, the transplanting operation should be set up in
a central headhouse area. Having all the materials
and workers in one area reduces materials movement
and makes supervision easier. A permanent set-up
may include the medium preparation and container
filling equipment, workstations, transplanting
conveyor or an automated transplanting machine.
Handling of the containers after transplanting can be
done with carts or a conveyor system.
BASICS
Before looking at individual systems, a review of
some basic principals is needed. In analyzing an
existing operation or planning a new one, many
alternatives face the grower. With changes constantly
occurring in equipment and methods, an up-to-date
review is necessary. It is worth the time it takes to
visit other growers, participate in conferences and
trades shows, and contact manufacturers and suppliers.
The knowledge gained will broaden your view and
make evaluation simpler.
Think Simple
Systems and equipment that you understand work
best. Fit the equipment to the size of your operation
and the tasks that need to be done.
materials (flats, plants, and so on) into and away
from the transplanting operations is very important
and will create a bottleneck if not handled efficiently.
Compare Equipment on Performance
and Capacity
Use manufacturers’ operating specifications to select
and size equipment. The equipment should meet your
production capacity needs, and the size and shape of
plug that will be transplanted.
Standardize Your Operations
Limit the number of sizes and types of containers to
reduce the inventory that has to be carried and the
time needed to make changes to equipment.
Purchase from a Manufacturer That
Has a Good Reputation
Check with other growers using the equipment for
efficiency, problems and dealer support. Obtain a
copy of the warranty.
Keep Employees Informed
Support from employees is important. Ideas and
input before changes are made and during the
debugging stages will help to make the transition
to a new system smooth. Training should also be
provided to develop the best techniques.
TRANSPLANTING BY HAND
Develop a Flow Diagram
A flow diagram shows the operations that are
performed and the movement of materials. Getting
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Efficient workstations can increase production 20 to
30 percent. In setting up the workstation, consider the
following.
Workstation Height
The best table height is elbow height. Adjustment
should be provided for different size workers. It is
best to provide for both standing and sitting
positions, as greater efficiency is achieved when
workers change position.
Hand and Arm Motion
The reach from the normal arm rest position should
be limited to a 24-inch (61-cm) radius to the side and
front for women and 27 inches (68.5 cm) for men.
The location of the flat that is being transplanted into
should be no more than 18 inches (46 cm) from the
resting elbow.
Location of Materials
Materials should be located as close to the work area
as possible. Walking 10 feet (3 m) to pick up or set
down a flat will add about 2 cents to its production
cost. Tipping the plug flat toward the transplanter can
reduce reaching distance. Prefilled containers eliminate
an operation. They can be supplied to the transplanters
by belt conveyor or on pallets.
Removal of Transplanted Flats
These can be placed on a cart next to the transplanter
or removed with a belt conveyor at the back of the
workstation.
TRANSPLANTING CONVEYOR
This piece of equipment, available from several
manufacturers, provides convenient workstations for
4 to 8 transplanters. The machine consists of a slow
speed conveyor belt that moves predibbled flats past
workers who place the plugs. The transplanters stand
or sit next to the conveyor with the plugs located
within arms reach. A variable speed motor on the
conveyor adjusts the speed from 5 to 50 ft/min (1.5
to 15 m/min) to adapt to the type of container, the
number of transplants handled, and the experience
of the workers. Workers are usually responsible for
transplanting into a certain section of each flat.
AUTOMATIC TRANSPLANTERS
The automatic transplanter has been developed over
the last few years. It can increase production without
additional help. Trays transplanted by machine
usually contain more uniform plants. The speed of
operation varies by machine. The slowest machines
will plant about 2200 plugs/hr whereas the fastest
will do up to 25,000 plugs/hr.
A typical transplanter contains several components.
The plug tray feeder and conveyor moves the
prefilled trays through a plug extractor to the
transplanting station. The prefilled flats are dibbled
before transplanting. At the transplanting station, the
plugs are removed from the plug tray by grippers
spaced to fit the transplant tray cell spacing and
planted into the transplant flat. Gripper style varies
with manufacturer. After transplanting, the flats are
usually conveyed to a watering tunnel before going
to the growing area.
To be efficient, materials have to be moved to the
transplanter and away from it at a constant rate. This
requires variable speed conveyors and associated
equipment. On the input end, soil mixing and flat
filling equipment is needed. For larger operations, a
blow-out machine that removes soil from cells that
don’t have plants, or have weak plants, and a fixing
machine that uses vision software to replace those
cells is available. This ensures that the transplanted
flats will have a full count of uniform plants.
With many models of automatic transplanters
available, how do you make a choice? Consider the
following:
Plug type – will the transplanter handle tree
seedling plugs?
Output rate – select a machine that meets your
peak rate needs with some additional capacity
for expansion.
Flat size – how easy is it to change from one flat
size to another?
Utilities – what are the electricity, water and
compressed air requirements?
Plug selection – is a machine with a vision system
needed to select only good plugs?
Control system – how easy is it to change the
computer program from one plug configuration
to another?
Service – what type of support does the
manufacturer provide?
Operators – how many people are required to
operate the machine?
On the output end, besides the watering tunnel that
wets the flats, equipment for bar code labeling or
tagging is also available. A system for moving the
flats to the growing area is also needed. Carts and
conveyors are commonly used. A more efficient
system is to use 6 feet wide x 12 to 20 feet long (1.8
m wide x 3.6 to 6 m long) growing trays that are
moved on a rail system. This reduces handling cost.
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ECONOMICS
Simple payback is a good way to compare different
transplanting systems. The projected savings/year are
divided by the yearly cost of owning the system. A 2
to 4 year payback is considered good. Payback can
also be calculated on a per flat basis. A typical US$
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5000 4-station transplanting conveyor may have a
payback of as little as 10,000 flats/yr. A US$ 60,000
automatic transplanter that will do 250 flats/hr may
require that you do a minimum 250,000 flats/yr to
get a 3 year payback. Information on the present
methods and the savings with the new system are
required.