THE CULTIVATION OF THE TOBACCO PLANT
CLIMATIC AND SOIL CONDITIONS. TREATMENT OF THE GROWING PLANT. SHADE
GROWN TOBACCO. HARVESTING.
THE CULTIVATION OF THE TOBACCO PLANT
A few general facts concerning the culture of the tobacco plant and its
treatment until it reaches the hands of the manufacturers will be of
interest for the smoker.
The general principles underlying the culture of tobacco are the same
whether it is intended for the cigar, pipe smoking or cigarette trade; but
the treatment of the leaf after it is harvested differs considerably.
Tobacco is a perennial plant. It is, however, usually raised each year
from seed. The seedlings are usually ready for planting towards the end of
May and are generally planted between the last week in May and the middle
of June.
The successful raising of tobacco depends on four principal factors: (1)
the climate, (2) the nature of the soil, (3) the seed, and (4) on the
method of culture.
The _climate_ must be such as to favor rapid growth and therefore must
furnish sufficient heat and moisture during the time the plant is growing.
The fineness of the texture and the elasticity of the leaf depend on the
climate.
On the _soil_ the plant depends for its food, and for the absorption of
those chemical constituents on which depend the burning qualities, the
strength and the color.
The physical qualities of the plant, structure and form, thickness of
veins, size, shape and distribution of leaves, are derived from the
_seed_.
Finally, on the _method of cultivation_ (including the curing process)
depends in part the final color, flavor and aroma; the type and trade
value; that is to say, on successful culture and harvesting and treatment
at the right time and in the best way, must depend the grower's hopes of
the final value of his crop. The quantity of nicotine, essential oils,
etc., on which flavor and strength depend, is regulated to the greatest
extent by the time of cutting.
The nature of the soil is a very important matter in the culture of
tobacco, for the color of the cured tobacco leaf depends almost entirely
on the soil. The light colored leaf is grown on light colored soil and the
darker leaf is grown on heavy, dark soil. The best type of soil for the
raising of tobacco intended for the cigar trade is a warm, deep, sandy
loam which rests on permeable well-drained subsoil. The very light colored
yellow tobacco cannot be raised except on light colored, porous soils; and
so susceptible is this matter of the coloring of the leaf that it has been
noted that the darkening of the soil by a liberal allowance of stable
manure will, on a very light colored soil, change the color of the
tobacco leaf from a bright yellow to a mahogany shade. Very light sandy
soils or very light loams with clayey subsoils are usually chosen for
these light yellow tobaccos. Although by processes subsequent to growth it
is possible to darken the color of tobacco leaf, there is no known process
that will make a dark leaf light in color.
Moreover, the soil must be very fertile and rich in the special substances
needed by the growing plant. This is all the more necessary because
tobacco is a rapidly growing plant, and reaches its maturity within a few
months after its planting. The rapidity of growth therefore demands a rich
fertile soil well stored with plant food. Good manuring, or liberal
treatment with fertilizers, is essential for keeping such soils in prime
condition, because the period of growing must not be extended.
Tobacco is usually planted in rows, the rows being from three to four feet
apart, the usual arrangement being that the plants are generally about 12
or 18 inches apart in the row. Some planters, however, give the plants
more room for many reasons, varying the distance between the plants even
as much as 30 inches. Cigar leaf tobacco plants are usually placed about
14 inches apart.
There are various operations necessary during the growth of the plant. The
most important of these for our purpose are those known as "priming" or
"thinning out" and "cutting." Priming is usually done when the plant is
well advanced in growth, but the time varies with different growers and
according to the species. It consists in removing the lower or imperfect
leaves from the plant, or these which have in any way become injured from
insect or other harmful agencies. As a general rule the larger the number
of leaves there is on a plant the lower is the quality of the subsequently
cured leaf. An average of about 10 leaves to each plant is what is favored
by most growers, and the plants are usually thinned to this extent. Seed
buds are removed also at the same time and for the same reason. If the
plants are "thinned" late and when they are approaching full growth the
leaves removed are not destroyed, but are cured separately and sold as
inferior quality and are usually called "primings" or "planters lugs."
In the Southern American States the time allowed for the growth and
maturing of the plant is somewhat longer than in the eastern and more
northerly states where the soil, owing to richer fertilization, favors the
rapid growth. Moreover, a stronger quality of tobacco is wanted and the
extra time allows the plant to effect a greater elaboration in its cells
of the oils and gums, etc., which contribute particularly to strength and
flavor.
SHADE GROWN TOBACCO
The matter of rapid growth has, however, its limitations. Too much
sunlight is considered a disadvantage. Under such powerful action,
nutrition is drawn quickly from the soil and the plants ripen too quickly.
Under such circumstances the leaves tend to become heavy bodied and not
very large in size. To defeat this tendency and produce large, thin silky
leaves for the cigar trade, the grower sometimes covers his field with a
tent of cheese-cloth or similar protection from the glare of the sun. The
ripening process is thereby slowed and the leaves are thinner, larger and
lighter in shade. This method is employed principally in Cuba, Florida and
Connecticut where cigar wrapper leaves are produced, and such tobacco is
known as shade-grown.
Tobacco which has been planted out at the end of May or early in June is
usually ready for harvesting at the end of August or beginning to middle
of September. The actual time of harvesting varies a good deal according
to the variety grown and the physical condition concerned in the growing
of the plant. The heavier tobaccos which are intended for the export trade
are usually harvested late. The most important operations connected with
the culture of the tobacco leaf are the "yellowing" and "curing"
processes, and, as these commence with the cutting of the plant, this
latter must be done under strictly favorable conditions in order to insure
proper results. The cutting must not be done while the sun is very hot, or
while there is rain, or before the plant is fully matured. On the other
hand, after the plant has reached its maturity, it must not be allowed to
continue its growth, which along with other things would be likely to
increase its nicotine content which is not desirable. The experienced
tobacco grower knows well from the appearance of the plant when it is best
fitted for cutting. The leaves become thick and heavy and assume a
drooping appearance. They become crisp with a tendency to break easily,
and a mottled, spotty look is noticeable on them. The surface becomes
gummy and oily; the oily substances increases and exudates as the days
pass. When these signs appear the tobacco is cut on the first day when the
weather favors. It is usual in most cases to split the stalks down the
middle and allow the leaves to wilt, before the stalk is entirely cut
through. After sufficient wilting the leaves are gathered in piles and
exposed to the action of the sunlight; or they are stuck by the stalks on
poles or framework and so exposed that the sun and air have free access to
all parts. This is the best and most approved practice. "Yellowing" of the
leaf is very rapid after the plant is cut; it is the natural effect due to
cutting off the food supply of the leaf and the consequent slow death of
the vitality of the cells. It must be remembered that the leaves are
large, varying in size (according to species) from 12 inches to over 2
feet in length. Such a leaf needs a large quantity of food and the sudden
cutting off of the supply effects a rapid change in appearance. The leaves
are allowed to hang on the scaffolds 3 to 5 days until they are fully
yellowed. They are then ready for the process of "curing," which is the
most important operation connected with cultivation. The "curing" and
"fermentation" which the leaf undergoes are chemical actions and their
success depends on the proper method of "yellowing." The leaves must not
be exposed to the sun too long, because the cells would lose their
vitality too rapidly and be unfitted for the new part they have to play in
the curing process. The chemical changes will be explained in subsequent
chapters. It is desired that the reader should understand that to ensure
a successful final issue the planter has need to watch continuously and to
know all the conditions. If the leaf does not "yellow" properly no amount
of after care in curing will make up for this deficiency. In tobacco
growing as in everything else, to ensure final high quality each step in
the process must be executed with skill, care, and judgment.
The yield of tobacco per acre varies from about 300 lbs. of leaf in the
southern states to 1,000 lbs. or more in the eastern. 700 to 800 lbs. per
acre is considered a good average crop.
REFERENCES
KILLEBREW AND MYRICK. _Tobacco leaf; its culture and cure, marketing and
manufacturing._ Part I. New York, 1897.
BILLINGS, E. R. _Tobacco; its history, varieties, culture, etc._ Chapter
XIII. Hartford, Conn., 1875.
LAURENT, L. _Le tabac; sa culture et sa preparation production et
consummation dans les divers pays._ Paris, 1900.
U. S. DEPT. OF AGRICULTURE. Farmers' Bulletins Nos. 6 and 60. _Tobacco._
U. S. DEPT. OF AGRICULTURE. Bureau of Plant Industry. Bulletin 96.
_Tobacco breeding._