Plants in response to injuries exude gums
that have commercial as well as medicinal uses. Many trees
in the forest like Dhaora, Khair, Babul, Kullu, Palas, Salai
etc. produce gum. The Indian Standard Institution has specified
gums into three grades primarily on the basis of colour -
Grade I - White to amber, Grade II - Reddish pale yellow and
Grade III - Brown to black. Dhaora, Babul and Khair gums are
grouped together as Class-II gums to distinguish them from
Kullu and Salai gums that are termed as class I.
Availability and Spread
Undivided MP accounts for 50% of gum karaya
(kullu) production in country. Collection of Gums has been
very large in 70s and 80s, but has consistently shown negative
trend from beginning due to various reasons. According to
an estimate, MP has potential to produce 2000 MT of Gum.
Due to over exploitation of Kullu and Salai
trees for their valuable gums, State Govt. had banned the
extraction of these gums in year 1982 and 1992 respectively.
In 1995, the state Govt. relaxed the ban on extraction of
Kullu gum (Gum Karaya) in Morena, Bastar and Khandwa districts
and since then its extraction is carried out through primary
cooperative socities. In 1992, the state Govt. lifted the
ban on extraction of Salai Gum in Gwalior, Shivpuri, Ujjain
and Khandwa circles. It was also permitted in Narmada Sarovar
submergence areas of Badwani and Jhabua forest divisions.
Phenology and Silviculture
Kullu and Salai gums are extracted usually
between November and June where as Babul exudes between March
to May.
Gums, a substance of sticky nature or plastic
consistency, are degradable products of the cell walls of
wood species and give a translucent amorphous look. Chemists
restrict usage of the term to substances that dissolve or
soften in cold water but are insoluble in alcohol or other
organic solvents. Gums are often mixture of gum and resin.
Resins often occur mixed in essential oil and are well known
as oleoresins, soluble in alcohol but not water.
Some plants only yield gum, some others only
resins and yet other both gum and resins. They are a group
of plant products related to sugars and carbohydrates, and
consist of polysaccharides or their derivatives. True gums
are formed as a result of disintegration of internal plant
tissue through a process known as gummosis.
Kullu also known as gum karaya is a beautiful
tree with white skin. It is found in dry forests in rocky
areas. Trees above 90 cm girth at breast height are tapped.
On an average, a tree yields one Kg of gum per season with
mid age trees yielding more gum. Salai is an important associate
of teak. The average yield of gum is about 1 kg per tree.
Though tapping does no injury to tree, method of tapping influences
yield. Babul gum exudes spontaneously, and hardens into rounded
or ovoid tears about a centimetre long and vary from pale
straw colour to dark reddish brown or almost black. Though
tapping is believed to accelerate flow, this is not practised.
Average yield of a tree is around 100 grams.
Utilisation
Gums have been in use since ancient times.
In Egypt, gums were used for embalming dead bodies and in
costumes. The varieties that have least colour and highest
adhesive power and viscosity are most valuable. Finer grades
are utilised in clarification of liquors, furnishing of silk
and preparation of quality watercolours. Kullu gum is one
such variety and highly valued in international market.
Intermediate grades are used in confectionary,
pharmaceuticals, printing inks, chewing gums, in sizing and
finishing textile fabrics, and in dyeing. Some of the gums
are used as nutritious fruit supplement and generally given
to ladies to recoup after pregnancy. In pharmaceutical industry
gums find further use for their emulsifying and stabilising
properties and also as suspending agents.
The cheaper grades are put to uses such as
adhesives, calico printing, and sizing of paper, and paint
industry. Paper industry uses gums as beater additives. Gums
also find use in cosmetics, paints, and ceramics.
Collection and processing
No uniform and definite form of tapping is
used. In most regions, for gum tapping, cuts are made on bark
so that gums ooze out from stem in liquid form and dry up
into translucent and amorphous tear shaped bodies or flakes
on exposure to atmosphere. Method of tapping followed is quite
crude that harms trees and harvesting of gums in long term.
Recent research has indicated that application
of ethephone, a commonly used formulation for stimulating
latex and resin flow can help in increasing gum production
by 20 times without permanently damaging tree through deep
cut. An intervention like fixing polythene under blaze mark
significantly improves quality of produce. Awareness about
grading can influence rates. Small samples of graded gums
with their market price could be supplied to collectors in
advance for the purpose.
In certain areas like Sheopuri, gums are
very important for the local economy, as many families are
dependent on it. In case of Salai Gum, the trees are an important
asset and are passed on to next generation as inheritance.
Still there are cases when gums exuded from the trees are
stolen in years like the present when the drought has been
3 years in the reckoning.
Production and Pricing
Figure : Production
figures of Class I & II Gums(in MT)
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