By Bechu Kumar Yadav
seedling is young plant saprophytes developing out of plant
embryo from a seed up to one metre of height and the term
seedling production is the production of seedlings for a
certain purpose, especially plantation.
The scope of seedling
production has been brought by various issues on
environmental protection, forest production, tree
improvement, ecosystem balance, forest regeneration and many
To fulfill the demand and
objective of plantation, there are several techniques and
procedures of seedling production developed by experiences
and researches on it.
selection, site preparation, quality seed collection,
seedlings establishment, storage, protection, management and
supply are the components of high seedling yields.
Use of efficient machines and
strong supervision by experts has wide scope in it. Mostly
seedlings are produced in a nursery either from seed or from
vegetative parts. During the plant production, nursery
should be established in which beds are prepared for seed
sowing and germination of seeds, root-shoot cutting, etc.
For very minute seeds, a seed
tray for seedling production is prepared filled with
different media such as coarse sand, fine soil, forest soil,
etc. Sometimes, plastic covered shade house or green house
is constructed, where seed trays are placed and seeds are
sown in tray for quick germination because there are
humidity and temperature controlled.
After germination when
seedlings gain height or form of 2-4 leaves, they are picked
out and transplanted into poly bag or in other type of
Overhead shade is provided
for root and shoots’ setting and to gain resistance and
gradually seedlings become hardened, overhead shade is
removed when plants are ready to transplant.
Seed Sowing:Seeds may
be sown by two ways either directly into the pots or it may
be sown first in seedbeds or seed trays and the seedling are
later picked out into the pots. Generally, Sowing seeds
directly into the pots should be used only with fairly large
seeds having a germination percentage of more than 40%.
Some species that are usually
sown areAcacia catechu, Artocarpus lakcocha, Bassia
butyracea, Albizea spp., Pinus etc. Methods of direct sowing
are also divided into three parts ;
Broadcast sowing: in
this method, the seeds are merely scattered over the surface
of the soil. For example, Alnus nepalensis has been
successfully established along the lamosangu –charikot road.
Line sowing: usually
strips 30-45cm wide are cleared and hoed depth of 15cm or
more. it commonly requires 15-20 times as much seed per
hectare as would be needed if the same quantity of seeds was
used to raise plants in nursery.
Patch sowing and sowing in
pits: This is sowing of seeds by forming pits and
patches in nursery. The development of root of seedlings
should be better in pits than patches. This is observed in
acacia catechu forest in Pokhara valley.
The optimum time for sowing
seeds on most sites is during the premonsoon rains as soon
as the soil has been sufficiently moisture .In areas where
snow can be relied on, sowing before the first snowfall
often gives good results, the seed will germinate after the
Cutting: Cuttings can
be done differently such as Branch cutting, stem cutting and
root shoot cutting.
Layering: Layering can be done into two ways, i.e., Ground
layering and Air layering.
veneer-graft, splice/whip and tongue-graft and underbark
graft. A scion is used to stock for seedling production.
Budding: An bud of
desired spps is used to stock of inferior species
Tissue culture: Tissue
culture (often called micro propagation) is a special type
of a sexual propagation where a very small piece of tissue
(shoot apex, leaf section, or even an individual cell) is
excised (cut-out) and placed in sterile (aseptic) culture in
a test tube, Petri dish or tissue culture container
containing a special culture medium.
The culture medium contains a
gel (agar) with the proper mixture of nutrients, sugars,
vitamins and hormones, which causes the plant part to grow
at very rapid rates to produce new plantlets. It has been
estimated that one chrysanthemum apex placed in tissue
culture could produce up to 1,000,000 new plantlets in one
Thus, tissue culture is used
for rapid multiplication of plants.A very specialized
laboratory is required for tissue culture.All the procedures
are done in a laboratory and special ventilated cabinet that
is as sterile as an operating room.
techniques in plant tissue culture may offer certain
advantages over traditional methods of propagation,
production of exact copies of plants that produce
particularly good flowers, fruits, or have other desirable
quickly produce mature plants.
production of multiples of plants in the absence of seeds or
necessary pollinators to produce seeds.
regeneration of whole plants from plant cells that have been
production of plants in sterile containers that allows them
to be moved with greatly reduced chances of transmitting
diseases, pests, and pathogens.
production of plants from seeds that otherwise have very low
chances of germinating and growing, i.e., orchids and
clean particular plant of viral and other infections and to
quickly multiply these plants as 'cleaned stock' for
horticulture and agriculture.
tissue culture relies on the fact that many plant cells have
the ability to regenerate a whole plant (totipotency).
Single cells, plant cells without cell walls (protoplasts),
pieces of leaves, or (less commonly) roots can often be used
to generate a new plant on culture media given the required
nutrients and plant hormones.
Type of Containers
(plants in polypots): Raising plant s in polythene
containers has become general practice for afforestation in
tropical countries, mainly because the rate of survival of
seedling is higher especially under unfavorable conditions.
They also reduce the rate of
failure due to the careless handling by inexperienced labor.
Other advantage are that nurseries do not need good soil.
The slandered container for raising plants in the nursery is
a polythene pots, 3inch*7inch (7.5cm*18cm) lay flat closed
at the bottom and made up of transparent 200 gauge polythene
with two holes on the side of drain out water.
When filled each about 2.5cm
in diameter. Black polythene pots are now being used raised
seedlings as it is slower to degrade under the effects of
sunlight, also prevents the growth of algae within the pots.
Especially nurseries above 1500m elevation or where
seedlings have to be kept in the pots for more than year,
black polythene is preferable.
Bare-root plants: In
this system, seedlings are not grown in separate containers
but together in a bed with thousand of plants of others. It
is best suited to species with medium to large size seed
e.g. pinus spp. The main advantages of bare-root are that
they are much easier to transport than plants in containers.
seedling: These are plants of 75-150cm in the nursery
for 12 months or longer, and lifted with a ball of soil
around their roots 10-15cm in diameter, which is usually
wrapped in grass, sacking etc. to keep it moist during
transports. This is traditional method in Europe,
practically for raising ornamental trees but has been
largely replaced growing plants in large containers of
plastic and other materials.
Stump (roots and shoots
cuttings): Stumps are prepared by digging up plants from
nursery beds, cutting off the stems a few containers above
ground level, and shortening and trimming the roots. This
method is much easier to transport than container raised
plants and less subject than bare root plants.
Cutting and other
vegetative propagated methods: The main use of cutting
and other vegetatively propagated materials is when species
to raise from seed or seed is not readily available. They
also have the advantage of reducing the time needed in the
nursery to obtain plants large enough for planting in the
field. Another advantage of cuttings is that they are
genetically identical with their parent trees so that trees
of good form and vigor can be reproduced easily. Cuttings
can be classified as: Stem cuttings, Leaf cuttings, Leaf bud
cuttings & Root cuttings.
Care and Handling of
From the time you receive
your seedlings until they are planted, proper care is vital
to maintain their healthy condition. Remember, seedlings are
perishable. So, it's the best to plant them as soon as
possible once you have received your order. Here are a few
seedling care and handling tips to keep in mind:
exposure to wind and sun during transporting seedlings.
in refrigerated location, if available.
for ventilation around stacked seedling packages.
seedlings from freezing temperatures.
any accidental tears in the seedling package with tape to
reduce moisture loss.
not water seedlings. Watering will wash away the protective
gel applied to the roots at the nursery.
seedlings from direct sunlight and wind before and during