Page 10 - NRG of commercial importance

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(d) Bore hole methodr Forest Research
Institute, Dehradun has developed a new
tapping technique known as bore hole
technique of resin extraction fiom Pinru
roxbr.oghii. In this method holes are made near
the ground level with the help of a machine
into tree's sapwood to open the resin ducts
and exudating resin is collected in a closed
container. The hole in each tree is done
approximately 10 cm above the ground. It has
been found from the studies that holes of 15
cm depth and 2.5 cm diameter are suitable for
obtaining maximum resin yield. The holes
are drilled snaight into the tree stem with a
slight slope towards the opening so that resin
drains freely.

Immediately after making the hole the
stimulants/ chemicals (mixture of sulphuric
acid and ethephon i.e., Z-chloro-ethyl Bcne hoh mahod
phosphonic acid) are sprayed inside each
The technique is very suitable for the
fieshly made hole. Spray volume of 1 to 2 ml
protection of tree against fire, insect, pest
are applied to each hole. Chemical treatment
and diseases.
is done once only, immediately after boring
Prolong resin flow can be obtained fiom
holes. After treatment a spout is installed
bore hole for a period of several months
inside the hole by gendy hammering with a
without wounding the stem.
small mallet or pushing with palm of the
The holes are made with the help of a
hand to achieve compression fitting in the
machine, therefore the labour
hole. The spout is meant for joining the
collection container (polybag made up of productivity of the technique is several
high density poly ethylene, HDPE, 35 .3 x lZ folds greater than other method.
The technique could be very'effective in
cm) tightened to each spout.
conservation and management of pine
Once the polybag is filled with resin, it is
resources.
removed from the tree and poured into a
Period o{ hanrsting/collection: Rosin from
collection can and immediately a new poly
chir pine forests are tapped fiom April to
bag is tied for future collection ofresin. Some
o of the advantages of bore hole method of November each year. Most of the forest trees
re.sin extraction are as follows, are owned by Government while a small yield
is also obtained from private or community
o There is less stress due to srnall size (2.5 forest
I cm diarneter) of the hole. The hole heals Yield: Experiments conducted on ftees
fast.