The genus Cinnamomum

216 K. Nirmal Babu, P.N. Ravindran and M. Shylaja
Camphor tree plantations are managed like forest tree plantations. Some initial
weeding is undertaken, (up to five to six years), after which the tree canopy grows and
prevents weed growth. When grown for leaves trees are topped at about 2 m height and
coppiced to encourage a bushy growth.
Diseases and insect pest problems are minimal, though some of the insect pests and
pathogens affecting cinnamon and cassia also affect the camphor tree. Plant protection
measures are seldom employed.
Harvesting and Camphor Processing
In the major producing countries such as Japan and Taiwan, camphor is obtained by the
distillation of wood from trees that are 50-years old or older, while in other camphor
growing countries such as America and India the practice is to utilise twigs and leaves
for camphor production. This latter practice has the advantage of an early yield, as
plants of about five-years old can be harvested for leaves and used for distillation. In
such cases where the leaves are harvested for distillation, camphor trees are maintained
as bushes. Camphor tree coppices grow vigorously and shoots grow rapidly. New leaves
take about two months to grow to full size and cropping at two-month intervals is
possible. Usually leaves are harvested three to four times a year in India as well as in
Sri Lanka.
The Japanese camphor industry
An account of the Japanese camphor industry in its heyday is given by Hiraizumi
(1950), on which the following discussion is mainly based. Traditionally, Japan has
been a major producer of camphor. Camphor trees existed in abundance in south Japan,
the main areas being the islands of Kyu-Shu, Shikoku and the southern part of
Hon-Shu. In earlier times the camphor industry was a government monopoly. Due
to unrestricted exploitation the camphor tree population dwindled very much and
the government of Japan embarked on a massive replanting programme in the years
following the Second World War.
In Japan camphor and camphor oil are distilled from the wood of trees that are
25-years old or more. Before a camphor tree is felled, the soil is removed from its base
to expose the root system, and all the roots, as much as possible, are removed. Then the
tree is cut close to the ground. Roots, stump, trunk and branches are all cut into
a convenient size and transported to the distillation factory. In the factory, the wood is
reduced to small chips using mechanical chippers and fed into a distillation still.
Essentially a distillation unit consists of a boiler, a retort (vat or still) and several
condensers. The boiler is an iron pan in which water is brought to boiling, and its size
varies from 1.2m to 1.5m depending on the size of the retort. The fire box beneath the
boiler is constructed of stone or fire-brick. The retort (still), known as koshiki, consists
of a wooden tank without a bottom and rests upon the boiler, but the two are separated
by a pine wood grid that consists of many holes for the passing of steam. Camphor
wood chips are charged into the retort and covered with a heavy lid. Once the distillation
is completed, the exhausted waste is taken out through a man hole at the bottom
of the retort, just above the grid. The capacity of stills vary from 600kg to 800kg.
A pipe about 10 cm in diameter runs from the upper part of the still to the condenser.
Usually a series of condensers are connected, and all connections are made air-tight.