The camphor tree (_Camphora officinalis_) is a large evergreen, native
to Asia. It is hardy in situations where the winter temperature
does not fall below 15° F., and for many years has been grown as an
ornamental in the southern and southwestern United States. Young trees
suitable for planting as ornamentals may usually be obtained from the
nurseries in Florida and other parts of the South, or they can be
easily grown from fresh seed.
For culture on a commercial scale the climatic requirements of camphor
are practically the same as those of citrus fruits. The tree can
be grown in almost any soil, but the maximum growth is secured in
soils which are rich and well drained. When planted for commercial
cultivation new land is preferable. The following statements are based
upon actual experiments and observations on the growing and production
of camphor under conditions found in Florida.
Camphor seeds ripen about the middle of October and should be planted
while fresh, a better germination being obtained when the pulp is
removed. The seed bed should be selected with care and the precaution
taken to have one that will give sufficient moisture during the dry
season and yet be well drained. For small seed beds of 2 or 3 acres or
less it may be practicable to provide irrigation. Excellent stands of
seedlings have been obtained on slightly rolling land which originally
was covered with "blackjack" oak.
About the first of September, or somewhat earlier if conditions permit,
the land should be well plowed and thoroughly worked down with a disk
harrow. Just before the seeds are planted it should again be worked
over and all roots of Bermuda grass or other weeds removed, since
rapidly growing grasses or weeds will absorb so much moisture from the
soil that the seeds can not germinate.
The seeds begin to ripen during the first part of October and are
usually in a fairly well ripened stage by the last of that month. From
this time until the heavy frosts they can be gathered and planted
with safety. Seeds gathered after heavy frosts have been planted
successfully, but it is not advisable to take the risk of too hard
a freeze. In determining the time to gather seed a simple test is
sufficient. Seeds that fall into the hand when the cluster is slightly
twisted are ripe enough to plant.
In planting, a cotton-dropping machine, modified somewhat to meet the
new requirements, may be used. The machine is set to plant the seeds 2
or 3 inches apart and cover them 1 inch deep in rows far enough apart
to permit horse cultivation. The plants begin to come up in about three
months, but four or five months are often required for a full stand.
As soon as the plants can be distinguished in the rows cultivation is
begun, which at first is done by hand with either a wheel or hand hoe.
Later, as the plants attain size, a horse cultivator can be used, but a
certain amount of handwork is necessary throughout the time the plants
remain in the seed bed. When the plants are well started they should
receive a good application of sheep or goat manure or of high-grade
fertilizer.
The first season a growth of from 3 to 18 inches may be expected,
the irregularity of development depending on the vitality of the
seed, variation in the soil, and numerous other factors. The plants
are allowed to grow in the seed bed usually for a year and are then
transplanted to the field. In transplanting it is customary to separate
the plants into two grades, "sturdy" and "weak," planting each grade
in a field by itself. By doing this the replanting is simplified,
since the sturdy stock requires but few trees for replanting and the
weak stock, which will require considerable replanting, is all in one
section.
Previous to transplanting, the land is well prepared by deep plowing
and thorough harrowing, and rows are laid off 15 feet apart. The young
trees are set in these rows 4 feet apart, either by hand or with a
tree-setting machine. This machine is simply a tobacco-setting machine
fitted with a trench opener set to open a furrow 8 inches deep, in
which the trees are placed. The trees used for transplanting are
headed back to within 1 inch of the crown, and the lower end of the
taproot and all large laterals are removed. The taproot of the tree
as planted is thus reduced in length to 8 or 10 inches and varies in
diameter according to the vitality and previous growth of the seedling.
Transplanting should be done in the winter months, when the trees are
dormant.
Cultivation is begun as soon as the trees put forth shoots in the
spring and continued until the rainy season of each year. After the
rainy season the plants are again cultivated and all grass and weeds
removed. At times cultivation is necessary during the rainy season
in order to keep the trees from becoming smothered and killed by the
fast-growing weeds. One-horse cultivators drawn by mules or a gang
cultivator drawn by a light tractor may be used.
In three or four years, after transplanting, the trees should be from 7
to 8 feet high. They are then trimmed by means of a special machine[3]
to form an =A=-shaped hedge and the trimmings distilled for the oil
and camphor gum. Trimming is carried on when the trees are in the
dormant stage, which is twice each year, usually November to January
and May to June. The summer dormant season is somewhat irregular and
governed entirely by local conditions.
[3] A detailed description of this machine is given in U. S. Dept. of
Agr. Cir. 78, entitled "A Machine for Trimming Camphor Trees." 1920.
The cuttings are hauled from the field to the distilling plant, and if
many large branches are present they are run through a heavy ensilage
cutter. For distillation they are packed in large iron retorts, to
which steam is admitted at the bottom. The outlet pipe of the retort is
connected with a specially constructed condensing apparatus in which
the oil and camphor carried over by the steam are condensed and partly
collected. Portions of oil and camphor not collected in the condenser
are caught in a tub fitted with an outlet siphon which carries away the
excess condensed steam but leaves the oil and camphor behind.
When removed from the condenser the product is very crude, consisting
of a mixture of oil, water, and camphor. This mixture is either thrown
into a centrifuge and the oil and water removed or it is placed in
large cylindrical vats and the oil and water allowed to drain out. The
oil is then separated from the water by means of a siphon. The camphor
and oil are marketed separately.
The annual yield of cuttings has varied from 2 to 5 tons per acre,
which should give approximately 40 to 100 pounds of marketable camphor.
At present the planting of small areas does not seem advisable, in
view of the heavy outlay required for the machinery necessary to
produce camphor gum at a profit. An area of less than 500 acres would
probably not warrant the installation of the machinery necessary for
the commercial production of camphor, and 1,000 acres or more will
doubtless give a greater net return per acre. Although the crop is
a low-priced one, under favorable conditions it is estimated that a
fair return per acre may be expected, but the data so far accumulated
are not sufficient to warrant specific statements concerning the
profitableness of the industry.
Camphor oil, or the oil from which camphor has been removed, is used
in Japan for illuminating purposes, and as a solvent for resins in the
manufacture of lacquer. It is used in Europe for its safrol content,
and may probably be utilized for the same purpose in this country.
There exists already in the American market a demand for the Japanese
oil at prices ranging from 11 to 14 cents per pound.
Camphor imports into the United States usually exceed 3,000,000 pounds
annually; hence, it does not seem probable that there is any danger of
overproduction in the Southern States. However, it is possible that at
times camphor may be imported at a price so low as to render production
in this country financially unprofitable.