1. PRESENTATION ON TOBACCO
Made BY
Mahmudul Hasan Rifat
Faculty of Agriculture
Sylhet Agricultural University, Sylhet-3100, Bangladesh
2. INTRODUCTION
NAME OF THE CROP: Tobacco
Name Of The Family: Solanaceae
Name Of The Genus: Nicotiana
Geographic Origin: The Americas
Part(s) Of The Plant: Leaf
Major Producers: China, Brazil, India
1
NAME OF THE CROP: Nicotiana tabacum
Fig: Tobacco plant
3. D I A G R A M O F T O B A C C O L E A F P R O C E S S
Tobacco
leaf
Harvesting
of leaf
Symptoms of
maturity
Methods Of
Harvesting
1) Priming
2) Stalk Cut Method
3) Leaf-wise Method
4) Whole Plant Method
5) Gugro Method
Curing
Air Curing
Fire Curing
Sun Curing
Flue Curing a) Yellowing of leaf
b) Fixing of color
c) Drying of leaf 2
4. Inter-cultural Operation
3
1. Topping:
2. Suckering:
• When tobacco crop is half-grown, flower buds begin to appear
• These flower heads are removed or ‘topped’ to prevent seed formation
• With the aim of producing large, thicker and darker leaves
• As a result the leaf mature more uniformly and contain more nicotine
• After topping, the secondary stem grows from the base or leaf axils
• These sucker must be removed to assure uniformity and quality
• Every seven to ten days suckering should be done by hand
• Maleic Hydrazide chemical used to prevent sucker development
5. 4
Symptom Of Maturity
• Change in color from normal green to yellowish
• Thickening of leaves due to more starch accumulation
• Accumulation of gummy substance
• Flowering of plants
• Brittleness of the leaves
Chemical Identification
• An objective test paper which is a modified starch iodide paper
• Developed by Sastry et.al. in 1969
• To determine the stage a drop of leaf juice is placed on the moistened list paper
• Then if color change into
Green = The leaf is immature
Blue = The leaf is over mature
Colorless = The leaf is mature
6. 5
Methods Of Harvesting
Priming
• It is the best method of harvesting
• The leaves are harvested when they are fully developed and matured
• All leaf gets sufficient time and nutrient for full development
• It is a time consuming and expensive method
• Cigarette & cigar (wrapper) are finished products
Stalk cut method
• Plant all leaves are intact and cut from close to the ground
• Maximum number of leaf should be matured to assure quality
• The leaves are not separate until 3-4 days
• Cigar (Binder & filler), Cheroot, Chewing, Bidi and Hookah
7. 6
Leaf-wise method
Only matured leaves showing full pledge development are picked and placed on the ground face down
Whole plant harvest
Whole plant is cut at bottom when almost all the leaves are matured and kept inverted at the same place
for drying
Gugro method
Normally harvesting is done 3-4 weeks after topping but it again depends upon the type of finished
products
Bidi Tobacco Harvesting Method
8. 7
Curing Of Tobacco Leaf
• In general terms, it is a process by which the harvested leaves are
made ready for marketing
• In technical terms, it is a process of drying, decomposition of
chlorophyll unit as a result the green color disappears from
harvested leaves, hydrolysis of starch into sugars and respiration or
fermentation of sugars
• Objective: Dry the harvested green leaf in such a way that the
final product has required color, texture and aroma
9. 8
Air Curing
• The source of energy is the atmospheric temperature carried
through air
• The leaves are spread or hang in the shade or in a ban
• A proper regulation of atmospheric temperature, oxygen and humidity
results in a better quality cure.
• Stage of Air Curing:
1. Yellowing of leaves
2. Development of brown color
• For high grade tobacco cured leaf this method has a little value as the leaves give up their moisture slowly
and turn into a brown color and the loss of dry matter is almost 22%
• There are main 3 method for Air Curing:
1. Ground Curing 2. Rack Curing 3. Pit Curing
Fig: Air Curing Process
10. 9
Fire Curing
• Firstly, all the leaves are wilted for few hours in the field
• Then tied into bundles of 3 to 4 leaves and hung on racks in a smoke
hut
• During this treatment some creosotic substances produced from the
smoke and absorbed by tobacco leaves that imparts particular taste
and antiseptic properties
• Then the leaves are fermented for 3 to 4 weeks after smoke
treatment and then treated with salt water form the lagoons or with
jiggery for a special or particular taste of this type
Fig: Fire Curing Process
11. 10
Sun curing
• Whole plant is strung on string or rack or spread on the ground
or leaves are tied into bundles and strung on rope
• The leaves are separated from the stalk after the plant are
initially wilted in the field
• Then the leaves are strung on bamboo poles for curing in the
sun
• Again they are spread and dried for 6 days then heaped for two
days and spread thereafter upto 4 days for drying
• Thus after 45 days the leaves attain dark brown color
• Then they are striped and tied into bundles of 25 to 30 for
fermentation
Fig: Sun Curing Process
12. 11
Flue Curing
• It is a improved method of Curing
• In this process drying the green leaves under artificial atmosphere
• It doesn't allow direct contact of leaves with the smoke or flames
• Temperature and humidity are regulated artificially
• It is raised with low nitrogen supply
• Leaves are harvested at an advanced stage of maturity so that
leaves are become rich in starch and poor in nitrogenous
substance like nicotine
• The leaves are always harvested by priming 3 - 4 leaves at a time
Fig: Air Curing Process
• In the production of FCV tobacco nearly 27% of the total cost of production is being spent toward curing.
• Adaptation of low profile barn which is an improved version over conventional barn(7.32m* 4.88m* 3.2m)
will help in accommodation 120 sticks in the barn
13. 12
Stage Of Curing
2.Fixation of color
It is a very critical stage and require 24 – 30 hours to fix the color. Any delay in
drying process deteriorates the quality by causing oxidation of tannin like
substance known as “sponging”. It show brownish tinge on the yellow leaves.
Sudden rise in temperature cause “scalding”. It Cause bluish back discoloration.
At this stage 80% moisture of leaf is driven off.
1. Yellowing of leaf
3. Drying of leaf
This process dry the midrib of the leaves and ventilators are closed for conservation of heat. 170 -180°F temperature are
maintained for 18 -24 hours for drying process of midrib in all parts of the barn. Entire process need 84 – 96 hours. After
drying door and ventilation kept open for absorption of air moisture. Cured leaves reduce 10-20% of green weight and
moisture ranging 8-18%.
It requires 24 – 36 hours or little longer gentle heating with the temperature of 90
to 100°F and relative humidity of 85 – 90%. It is a slow starvation process with the
aim of slow heating with optimum humidity to keep them alive for 30 – 36 hours.
At the end leaf attain a bright lemon yellow color and starchy matter gets
converted into sugars.
14. 13
Factor Affecting The Tobacco Quality
Relative humidity
Temperature
Air supply
Condition of the leaf
• A temperature below or above the normal limit will inhibit or slow down the curing process.
• Temperature should be with 60°F to 180°F depending upon the stage
• Highly important for the rate of drying
• On an average relative humidity should be 85% at beginning but after the leaves begin to turn yellow a lower humidity
that permits rapid drying
• As curing is a process of oxidation so air supply is required
• Air supply is met when ventilators are opened to regulate the humidity of the chamber
• The capacity of tobacco to cure and extant of process depend on the type of leaf, its degree of maturity and other
physical characteristics.
15. 14
Nicotine Content Of Tobacco
• Chemical formula: C10H14N2
• Nicotine is chemically related to pyridine and when oxidized yields nicotinic acid which is 2-
pyridinec carboxylic acid
• In pure state nicotine is a colorless, rather mobile, oily liquid which soon darken upon standing
• It is slightly heavier than water
• Usually dominant alkaloid present
• It is soluble in most ordinary organic solvents
• It boils at 247°F
• When leaf reaches at the full maturity the content of nicotine begins to decrease
• Topping always results in increased accumulation of nicotine
• In manufactured tobacco nicotine content is 1.5% to 2%
16. 1. Rudgley, Richard. "Tobacco: from The Encyclopedia of Psychoactive Substances". Biopsychiatry. Little, Brown and Company
(1998). Retrieved 26 November 2017.
2."WHO Report on the global tobacco epidemic, 2008 (foreword and summary)" . World Health Organization. 2008: 8. Tobacco
is the single most preventable cause of death in the world today.
3. Ernst, A. (1889). "On the etymology of the word tobacco" (PDF). The American Anthropologist. A2 (2): 133–
142. doi:10.1525/aa.1889.2.2.02a00020.
^ Lane's Lexicon. page 1879.
4. The word ṭubāq no longer refers to various herbs, but has come to refer, in some dialects, specifically to tobacco. See Hans
Wehr's Dictionary of Modern Written Arabic. page 647.
5. Goodman, Jordan. Tobacco in History and Culture: An Encyclopedia (Detroit: Thomson Gale, 2005).e.g.
Heckewelder, History, Manners and Customs of the Indian Nations who Once Inhabited Pennsylvania, p. 149 ff.
6. "They smoke with excessive eagerness ... men, women, girls and boys, all find their keenest pleasure in this way." – Dièreville
describing the Mi'kmaq, circa 1699 in Port Royal.
7. Jack Jacob Gottsegen, Tobacco: A Study of Its Consumption in the United States, 1940, p. 107.
8. Appleby, Joyce (2010). The Relentless Revolution: A History of Capitalism. W.W. Norton & Company. p. 131.
REFERENCES
