Selecting a Tobacco Transplant Production System
Bill Maksymowicz and Gary Palmer
Farmers now have at least six choices for tobacco transplants:
- traditional plant beds,
- precision seeded beds,
- direct-seeded greenhouse plants,
- plug and transfer,
- container-grown boxed plants, and
- bare-root plants.
There is no "right" system for everyone; an ideal system for
one producer may be a costly nightmare for another. The
following outline provides some general information about each of
Traditional Plant Beds
Experience has shown that there is more to providing
an adequate supply of plants from a conventional bed than
scattering seed and expecting there to be a good, uniform stand of
plants when you pull the canvas. A good management program includes:
Traditional plant beds have been used successfully for
years, but proper management is necessary to produce an
adequate number of healthy transplants. Producing plants in a traditional
bed requires no major cash outlays. Transplant cost is generally
less than 3.5 cents each. Diseases and insects can be
effectively controlled with currently labeled pesticides. Once plants are
pulled they should be used within 2 to 3 days.
- Fumigating when temperature and moisture conditions are correct. Any equipment used on the bed should be cleaned and treated with a chlorine solution afterwards to minimize disease spread.
- Proper water management. Most plant bed losses are due to dry soil conditions. Beds should be irrigated as needed to a depth of 6-8 inches.
- Insect and disease control. Beds should be scouted at least weekly after emergence. Contact your local county Extension office for updated information on chemicals and spray schedules.
- Proper fertilization. Over-fertilization can result in rapid, succulent growth that produces a weak transplant subject to bruising and disease infection. Excessive use of processed sludge or other organic types of fertilizer may result in plant death due to high levels of trace elements sometimes present in these materials.
Precision Seeded Beds
In the precision seeding system pelletized tobacco seed
is drilled, using a special seeder, in a bed that has been prepared in
a traditional manner. These seeders are expensive, so the
seeding operation is done on a custom basis. The same
recommendations that apply to conventional beds apply to precision-seeded beds.
The goal of this system is once-over pulling, so the beds
will need to be clipped more frequently than conventional
beds. Sanitation of seeding and clipping equipment is critical to
This system has the same costs as those for a traditional
plant bed, plus the additional cost of custom seeding, mower,
and undercutter to use when pulling the plants. Labor costs at
pulling should be less than with a traditional plant bed, but other costs
in equipment and custom-seeding make transplants from this
system slightly more expensive than traditional bed plants.
Direct-Seeded Greenhouse Plants
Direct-seeded greenhouse plants are relatively new
to Kentucky tobacco producers. High quality transplants can
be grown that can minimize production problems throughout
the growing season. The down-side is that failure can often mean
total failure, leaving the grower without plants.
Be aware of these precautions if you are new to this system
When correctly managed, plants produced under this system:
- Sanitation is critical. There are limited chemicals available to deal with greenhouse tobacco disease problems, so it is essential to exclude diseases from the outset.
- Initial cost is high, but at the present reliable suppliers are offering extremely competitive packages compared to houses available for horticultural use. Shop around, but make sure you know exactly what is included in a package when comparing prices. Most "complete" packages do not include lumber for end walls or float beds and electrical supplies. For a more realistic cost estimate, add 15-20% to the package cost of the house.
- Generally, as you increase the number of plants per tray you increase the need for management and potential for disease problems. The 200-cell tray is the most forgiving in terms of management, but does not optimize floor space efficiency (number of plants produced per unit area of the greenhouse).
Using a higher density tray242, 253, 288, or 338
cells/traygenerally means higher management and
increased likelihood of disease problems. It is more difficult to hold plants
in smaller cell-size trays for an extended time if weather conditions
do not allow transplanting. However, there have been no
differences in survivability or yield among plants set at the same time
from different-sized cells, providing the plants taken to the field
- Management is the key to
success. If you are not able to commit an individual to the management of the house,
especially during the first 4 to 5 weeks, serious losses could result.
Individuals who have been unsuccessful with traditional plant beds or the
plug and transfer system will probably not be successful with a
- Obtaining high quality seed is
important. Good seedling vigor as well as high germination percentage give the
best utilization of floor space.
- Setting-size plants can be produced from seed in 7 to
12 weeks depending on how the house is managed.
The need to reset is virtually eliminated. Research indicates
that plants will be ready to top and harvest 5 to 10 days earlier
than plants set at the same time from a conventional bed, with
no differences in leaf number or total yield between transplant sources.
- are easy to set (especially with a carousel setter),
- are all the same age and size,
- exhibit almost no transplant shock, and
- tend to grow off more evenly.
Some growers report more ground suckers with
greenhouse plants. This is caused mainly by plants being set too shallow or
not being set straight in the ground. Ground suckers are usually
more prevalent under high soil moisture conditions, regardless
of transplant source.
These systems require a high initial capital investment for
the greenhouse, seeding, and mowing equipment. Per plant costs
can be reduced if more than one tobacco crop is produced in the
house each year. Over 7 to 10 years, transplants from this system
should be only slightly more expensive than those produced by
Plug and Transfer
In the plug and transfer system a producer buys
small seedlings from a plant supplier, transfers them to larger trays,
and floats them in a simple outside water bed for about four weeks.
There is no "standard" water bed; they are often built to
fit materials on hand. These are some general guidelines:
If you are considering greenhouse construction you may
want to try plug and transfer first. All material used for plug and
transfer can be used in the greenhouse, and starting at this level will
give you some relatively low investment experience with
- smooth, level area is required for the beds. Five inches
of water should be adequate for 4 weeks of growth. Sand or
sawdust may be used to level an area.
- Insulation board under the plastic liner will help retain
heat, especially if water heaters are used. One water heater per
100 square feet of surface area can be helpful, especially if you
transfer before May 1. Although a water bed heater can help regulate
or improve plant growth it will not prevent cold injury or
prevent freeze damage.
- When considering this system remember that there are
time and labor involved in the transfer. Fill your trays a day or
two before the plants arrive to minimize transfer time. Stack trays
and cover with plastic to prevent the mix from drying out before
using them. With a little experience you should be able to transfer
1200-1600 plants per hour.
- There have been problems with soil mix that has
fertilizer mixed with it; since so little fertilizer is required uneven mixing
of the fertilizer and mix can result in poor or uneven growth. Scout
the beds and add fertilizer if necessary 2 to 3 weeks after
transferring. Water-soluble fertilizer with a high nitrate source of N mixed
with the water has produced the best and quickest response.
- Clipping the plants one or two
times produces a stockier plant. Clipping also allows easier setting with a carousel setter.
Do not clip off an excessive amount of plant material unless you
are trying to hold the plants; in any case, be sure that you do not cut
off the terminal bud.
Other transplant source options include both
container-grown and bare-root
transplants. The key to success with these sources is dealing with a reputable supplier. You should
assume, especially when dealing with plant-bed raised transplants, that
there is a risk of bringing in disease and insect problems.
Producers have been given more options on how to raise
or buy transplants in the last few years than they have had in the
last 50 years. No one system is the best for everyone.
Learn as much as you can about each system
through information available from your county Extension office,
meetings, trade shows, and experiences of others. Look beyond the cost
per plant when deciding which system is best for you. Consider
being able to schedule planting, and the reduced labor involved
in handling and setting container-grown plants.
The transplant production business is growing rapidly,
so shop around for the best value for your dollar. Know how
much time and money you are willing to invest and be sure of your
risks and options.
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