In the nature plant species have various mechanisms
for reproduction. Seeds, rooting on the stem, tubers and suckers are the important ones.
Plant propagation techniques became popular with modern horticulture for asexual multiplication
of commercial plants in large numbers. Grafting is an age-old practice. But its commercial
application and new techniques started few decades ago. Tissue Culture is one more popular
asexual method of multiplication of plants. But it is commercially successful only in
soft wood plants like banana, cardamom, flower and ornamental plant species.
Majority of the plants produce seeds. Then why do you need grafting? To answer this question
let us understand the problems of seedlings first. The male part of the plant � pollen
unites with the female part � ovule to form seed. Due to recombination of genes the next
generation plant differs in its characters than its mother plant. This variation is more
evident in case of cross pollination. Hence the seedlings from a sweet mango tree may
give sour fruit. Best jackfruit may become useless in next generation. Off course this
is the reason for the varietal diversity in nature. But in commercial horticulture we
need plants with similar characters for good quality and yield. Here the grafting techniques
help us a lot. Seedlings take long time to bear fruit. But
the grafted plants can give fruit after 2-3 years. Grafting technique is used to escape
from certain diseases in some crops. For example, grafting pepper on �wild pippali� is popular
to avoid wilt disease. A wild type of grape called �Dog ridge� can withstand drought
and avoid the absorption of poisonous elements. Grafting commercial varieties on this Dog
ridge brought revolution in grape production. Many ornamental plants do not produce seeds.
At the same time, they do not root easily from stem cuttings. For the multiplication
of such plants grafting technique is inevitable. Grafting is helpful to produce composite plants
with many varieties and for the rejuvenation of old trees.
Grafting means uniting 2 plants of the same species. Shoot of a required variety plant
is grafted on a seedling with a stout root system. Normally 2 different species will
not unite. Even then inter specific combination is possible in citrus, sapota, grape and in
few more plant species. Grafting is restricted only to di-cot plants. It is not possible
in mono-cot plants like areca nut and coconut. Graft plant is dwarf by nature since it is
from a lateral shoot. It spreads wider than its height. This helps for pruning, spraying,
harvesting and for other cultural operations. There are few problems too with grafted plants.
Some grafts fail to grow in to a tree affecting the yield. In nutmeg and kokum, only the shoots
growing up ward are used for grafting to get good trees from graft plants. In most of the
species the graft plant will not grow in to a huge tree. Hence, they are not useful for
timber purpose. Sometimes approach graft plants get damaged by heavy wind. Air layered plants
without tap root system cannot tolerate drought. Depending on the root stock you may find slight
variation in the quality of the fruit of the grafted plant. Due to incompatibility between
root stock and scion the graft may fail to grow properly even after the success of grafting.
Few viral and bacterial diseases are transmitted through graft plants in lime and pomegranate.
Even then the grafted plants play a vital role in commercial horticulture.
High temperature and high humidity are necessary for the success of grafting. Hence winter
and heavy rainy season are not ideal for grafting. Natural climate of the sea coast is the best
for the purpose. Hence most of the commercial nurseries erect poly houses for grafting.
But in medium rainfall areas shade house is enough for this purpose since the temperature
and humidity remains ideal in the rainy season. Now let us learn about poly houses meant for
plant propagation. We can categorize them like high cost, medium cost and low-cost poly
houses. This is a high cost poly house built for floriculture. This is very systematic
and durable. But it works out costly for propagation purpose alone. It costs Rs. 2 lakhs per gunta.
This is a medium cost poly house. Poly sheet is set on iron arches. Wind damage to the
poly sheet is minimal due to its shape. Cost of construction of this poly house is around
Rs. 75,000 per gunta. This is a low-cost poly house. It is built with locally available
wooden and bamboo poles. Technically this is no way inferior to the other types. But
care is necessary to protect the poly sheet from the sharp edge of the poles. It is necessary
to rebuild this after 2-3 years. It costs around Rs. 40,000 per gunta. Poly house of
1 gunta area accommodates around 10,000 plants. Temperature inside the poly house is 5 to
10? centigrade higher than outside even in rainy season. We can raise the relative humidity
to 90% by sprinkling water inside the poly house even in the winter. It is necessary
to bring down the temperature inside by keeping the door open in hot noon hours of the summer.
Success % and the growth of the graft plants are excellent in the poly house. We can retain
enough heat for night hours by closing the door by evening.
The poly sheet used in these poly houses keeps good for 3 to 5 years. This UV stabilized
poly sheet tolerates direct sun light. Put cement or apply coal tar for the wooden poles
to avoid termites. Select the type of poly house depending on your investment capacity.
Poly house is inevitable for higher % of success and large-scale multiplication of graft plants.
Government provides subsidy for these poly houses.
This is a systematic shade house. Young graft plants need nourishment and hardening in partial
shade at least for 2-3 months. The construction of this shade house is very simple and systematic.
G I pipes support the structure. Upper open end of the pipe is plugged with wooden piece.
Drip irrigation LLDPE pipes are spread in all direction to hold the shade net. This
support is good enough to carry the shade net of light weight. G I wires stretched to
the ground from the side support pipes keep the structure firm. Shade net is buried on
all sides to close the entry except the entry doors. Since the shade net allows the movement
of air the structure escapes the damage due to wind. Cost of construction is bit high,
but the structure keeps good at least for 5-6 years. This shade house is useful even
for general nursery purpose. Now let us discuss the actual subject of grafting.
Graft plant has 2 parts. Lower portion is from the seedling and is called rootstock.
Upper portion is from the mother plant and is called scion. Rootstock should be a sturdy
disease-free seedling with a strong tap root system. For mango grafts bigger mango stones
of wild variety are sown in beds. These produce stout seedlings. Stone of pulp variety and
the matured stones from pickle industry are also acceptable. Champaka and Rayon seeds
are sown in pots or poly bags to produce rootstocks. Scion should be a matured stem from fresh
growth of the mother plant. It should have a dormant bulged vegetative epical bud. Scion
should be free from diseases and insects like stem borer. It is better to cut off the leaves
of the scion on the mother plant itself 4 days before separation. Do not pluck the leaves.
But cut it off retaining the stock of the leaf on the stem itself. Use only the fresh
scions for grafting. However, it can be stored in a wet gunny bag for 2 days.
The principle of grafting is same in all the methods. Two stems will join if the cambium
cell layers of both stems are tied together after giving level cuts. In one more method,
roots are induced on the stem to get independent plant. Many methods of grafting are in practice
based on this basic principle. This is an age-old method of grafting. This
is in practice in important crop plants like mango, sapota, Champaka etc. Search a twig
of the mother plant which matches with the stem of the seedling in size. In commercial
nurseries ground nursery of dwarf mother plants are maintained for the purpose of approach
grafting. Otherwise a platform like this is put to facilitate grafting. Bring both the
stems together and put marks. Then give level cuts of 2 inches on both the stems. Let the
cuts be of 30 to 40% of the thickness of the stems. Use sharp knife to give level cuts.
Do not damage the stems with a blunt knife. This point applies to all methods of grafting.
Then keep both the stems together and tie with plastic tape. This tape avoids the entry
of air and water inside the graft joint and avoids drying. Tying jute thread is necessary
in this approach graft since both the stems are thick and stout. Now let us watch the
method once again. June � July months, the beginning of the
rainy season is the ideal time for approach grafting. Graft takes 2 to 3 months for healing.
During that period seedlings need watering. It is easy if the rain does that job. Give
vertical cut on the scion below the graft joint after the union seems perfect. Give
one deeper cut after one week. This brings down the dependence of the scion on the mother
plant. Scion starts absorbing water and nutrients from the seedling through the graft joint.
Then separate the graft from the mother plant. Cut off the seedling above the graft joint.
Keep on removing the sprouts on the rootstock below the union.
We can get a bigger plant in approach grafting by selecting bigger shoot for grafting. But
we can produce limited number of plants in this method. Due to the heavier upper portion
sometimes, the approach graft plant bends and breaks at the graft union. Watering the
seedlings is a difficult task on a large scale if the rain stops. Because of all these reasons
approach grafting is not being practiced by commercial nurseries.
What we are using here is a common plastic strip. It is not a gum tape. Soft stretchable
plastic of medium thickness is folded like this and cut for 1-inch width. This plastic
strip avoids air and water entering the graft joint. Remove the tape after the graft union
heals completely and the plant starts growing. Otherwise it makes constriction and limits
the growth. Even the plant may die. This point applies to all the methods of grafting.
The commercial nurseries producing grafts in large numbers follow stone grafting. Though
this is a simple method, the success rate depends on the skill of the grafter. Stone
grafting is commonly practiced in mango and cashew. Sow the stones in beds with loose
soil. Seedlings will lose the tap root while pulling it out if the soil is hard. Uproot
the copper colored young seedlings with entire root and the stone attached. Cut of the stem
leaving 2 to 3 inches above the stone. Make a slit of 1.5 inch with a sharp knife. Select
a scion of 4 inches in length and of pencil thickness. Give slant cut like this on both
sides of the scion. Keep the scion in the slit of the root stock and tie with the plastic
strip. Only the plastic is enough to hold the union since the rootstock is soft. Make
the packing air tight. Plant this tiny graft plant in a poly bag filled with potting mixture.
Put a poly pouch on the scion and keep the graft in a poly house. Let us watch the method
once again. Stone graft kept in an open place will fail.
But in a poly house the success rate is 70 to 80%. Scion fails to sprout if the rootstock
with leaves turned in to green is used. Graft fails to sprout if the stone is detached while
pulling it out from the bed or at the time of grafting. The reason is the stone is the
source of food for the graft plant till the scion produces green leaves. Successful graft
starts sprouting in 2 to 3 weeks. Then take out the poly pouch on the scion. Cut off the
plastic strip once the union is perfect and the graft grows fast. Keep on removing the
sprouts below the graft joint. Stone grafting is a successful commercial
method since one can produce large number of plants. The graft joint is at the base
and the plant grows straight. But this method produces tiny plant which needs more time
and nourishment to attain salable size. Because of this reason stone grafting is losing popularity
in recent years. Remember, poly house is essential for large scale stone grafting.
There is a method called double grafting in this stone method. The seedling from the stone
is very weak and is almost half of the thickness of the scion. Hence two seedlings are grafted
to a single scion. This makes the graft union strong and the plant will get two root systems.
Hence the growth of the graft plant will be better. Except to that the grafting method
is same. Now let us study the most popular method of
grafting called soft wood grafting. This is in practice in mango, sapota, jackfruit, cashew,
tamarind, brinjal, hibiscus and in many more plants. Let us graft a mango seedling first.
Grow seedling in a poly bag for one season. Even the older plant is useful. Grafting is
on the green-soft portion of the plant. Hence it is called soft wood grafting.
The grafting method is as usual. Cut off the rootstock above the green portion of the stem.
Keep few leaves below. Make a slit of 1.5 to 2-inch length. Give slant cut on both sides
of the scion like this. Then keep the scion in the slit of the rootstock and tie with
the plastic strip. Plastic is enough to keep the joint intact since the stems are soft.
Ensure that the packing is made airtight. Few leaves are necessary below the graft joint.
This is to feed the plant till the scion produces green leaves. Put a plastic pouch on the scion
and keep the graft in poly house for more % of success. However, the poly house is not
compulsory. Remove the pouch on the scion as and when the scion starts sprouting. Keep
on removing the sprouts below the graft joint. Otherwise the scion will die. Cut off the
plastic tape after the union heals perfectly and the plant starts growing. Otherwise it
will create constriction and the plant may die. Now let us watch the method once again.
Soft wood grafting is being used in many forms with few modifications. This is a mango seedling
of unknown variety. Even if it is good it takes many years to give fruits. We can convert
this in to a good variety by soft wood grafting. Cut off all the shoots leaving 3 to 4 healthy
branches. Graft at soft wood portion as usual. Even we can graft different varieties to each
of the branches to produce a composite tree. Many farmers plant seedlings on the farm at
required spacing. Then the plants are grafted in soft wood grafting method. This is called
�in situ� grafting. This method gives better success rate and further growth of
the plant. Now let us learn one more usage of soft wood
grafting. This method is being used on large scale for rejuvenation or change of variety
of old mango and cashew plantations. Cut off the tree at 2 to 3 feet height from the ground
in summer. It will produce many sprouts in 2-3 months. Then grafting is done to 5-6 selected
sprouts in soft wood grafting method. Put poly bags on the scions after grafting. Graft
union heals up fast and the branches grow quickly due to wide spread root system. This
graft plant starts yielding within 2-3 years. However, the old big tree may fail to sprout
after cutting at the base. Hence the trees up to 1.5 feet diameter are suitable for this
method. This method is successful in converting old seedling plantations of cashew.
Earlier there was one more method to convert old mango trees in to a graft plant. Here
the grafting is done on thick bark of the tree and hence it called bark grafting. Since
the bark is thick and hard it needs chisel and hammer to cut open it. Make two cuts in
an angle like this on the trunk just above the ground. Remove a small piece of bark to
facilitate the insertion of the scion. Loosen the bark without damaging it. Here a bigger
scion of 8-inch length and thumb thickness is used. Give slant cuts as usual to the scion.
Open the cut bark and insert the scion slowly. Do not damage the scion by pushing it down
forcibly. We may put 2 scions on the same trunk. To keep the bark in place it needs
tying with a rope like this. Paste the clay on the cut marks to prevent air and water
entering the graft joint. This scion starts sprouting within 5-6 weeks.
Union will heal perfectly and the scion gives out 2-3 fleshes within 6 months. Then cut
the tree above the graft union. Fell the tree in opposite direction without damaging the
sprouted scion. This graft gets the whole root system for feeding. Hence it grows in
to a big tree within 2-3 years and starts yielding. We come across many mango trees
grafted in this method. Side grafting is one more simple method which
is not in practice commercially. The old seedlings grown in a bag or pot is the rootstock. Give
a slant cut on the stem at 3 inch height. Cut the scion as usual and place it in the
slit of the rootstock. Tying plastic tape is enough to hold the graft joint. Scion sprouts
after 4 weeks. Then cut off the top portion of the rootstock above the graft joint.
Guava, pomegranate, lime, bread fruit, hibiscus, ixora, musanda, ornamental rubber and many
other plants produce roots on their stems naturally. But the rooting is not enough to
produce an independent viable plant for commercial planting. The systematic method of inducing
enough roots on these stems is called air layering.
Now let us study the method in detail. Bending and putting the stems in the soil for rooting
was the earlier practice. But the availability of such stems was very limited. Hence the
method was modified to root at any height of the plant. This called as air layering.
Select healthy twig of finger size for layering. Put 2 knife marks around the bark and take
out a ring of bark. Scrape the greenish cell layer on the stem to avoid rejoining of the
bark. To induce more root IBA hormone of 500 ppm concentration may be applied. Sphagnum
moss is commonly used as rooting media. This is a fern growing on trees in the forest or
on the ground in hilly region. This is a very loose medium with high water holding capacity.
This sphagnum moss is available for sale in the shops selling nursery equipment. Even
the saw dust and powdered organic manure are in use as rooting medium. But moss is the
best one. Wet the sphagnum moss; squeeze it to drain
excess water. Otherwise it will result in the decay of the stem and bark inside the
layer ball. Tie a plastic sheet with the help of jute thread below the layer mark. Hold
it upward to get a packet shape. Fill the packet with the moist sphagnum moss tightly.
Again, tie the opening at the top. Tying should be tight enough to make the layer ball airtight.
It will root within 5-6 weeks. After enough roots are visible put 2 vertical cuts below
the layer ball in a week interval. Then separate the layer from the mother plant. Cut off the
tender portion of the layer plant to minimize evaporation since the roots are yet to establish.
Remove the plastic sheet, plant it in a poly bag and keep it under shade. Now let us watch
the whole procedure of air layering once again. Air layering is the only commercial method
of propagation in pomegranate and guava. We can produce layers in large numbers if we
have enough mother plants. Air layering is a simple and cheaper method of plant multiplication.
But the plant dies after separation if the rooting is not proper. It is opined that the
layer plant cannot withstand drought since it has no tap root system. But now a day the
plantations will have assured irrigation. Hence the air layering has become a popular
method of plant propagation. Now let us study the delicate method of grafting
called budding or bud grafting. This is the only commercial method of multiplication in
rose. Budding is in practice even in rubber, lime, bur fruit and in many other plants.
Depending on the shape of the bark opening it is termed as �I� budding, �T� budding
and patch budding. Now let us bud graft the rose plant. Stem
cuttings of commercial variety of rose will not root properly. Hence the rootstock is
a wild non-flowering variety called Dog rose. Plant the dog rose cuttings in the field or
in poly bags. Select the scion stick from the required variety of rose. We find healthy,
fresh and bulged vegetative buds on the stick below the dried flowers. Cut off the leaves
of the scion stick. But do not pluck the leaves. Scoop the selected bud with the stalk of the
leaf and a small portion of the stem inside. Then carefully take out the stem part inside.
This bud scion is ready for grafting. Ensure that the bud do not dries up. Cut off the
other shoots of the dog rose leaving only one soft-fresh shoot. Remove the thorns to
facilitate easy budding. Put a mark of 1.5-inch length on the bark of the shoot with the help
of knife tip. Loosen the bark without damaging it. Insert the bud inside along with the portion
of the bark with it. Tie a plastic strip to make the graft joint air tight keeping the
bud open. It will take 3 to 4 weeks for sprouting of the grafted bud. Cut off the dog rose shoot
above the budding joint after the joint heals perfectly and the bud starts growing in to
a green shoot. Keep on removing the sprouts below the budding point.
Commercial rose nurseries plant the dog rose cuttings in poly bags itself. Even one can
transfer the successful bud grafts from the field to a poly bag. Budding is a simple method.
But the success rate depends on the skill of the grafter. Since the scion part is very
small we can go for budding in all the seasons. Grafting is a simple art to practice by a
farmer or a hobby gardener. Commercial nurseries sell only few popular varieties of plants.
Selling price is also high. Transportation adds to the cost of the graft plant. We can
propagate any plant or variety of our choice if we learn this art of grafting. Grafting
nursery as a subsidiary activity can generate an attractive income. Grafting is the basic
skill of agriculture. If farmer has not acquainted this skill his learning is incomplete.