Common Name: Tobacco

General Information

Nicotiana tabacum is an annual or short-lived perennial, erect, unbranched or sparsely branched plant with a well-developed taproot. It can grow 70 - 250cm tall[, ].
The most widely cultivated tobacco species, and one of the major non-food crops grown in the world, it is a rich source of the alkaloid nicotine and has a long history of use as a medicinal plant and social stimulant. It was cultivated in the Americas well before the arrival of the Europeans and is now widely grown in many other parts of the world including the USA, India and China[]. Originally used as chewing tobacco, later smoking tobacco varieties were selected[].
Nicotiana tabacum has been has been widely cultivated beyond its native range to produce the economically important crop tobacco, but it has escaped from cultivation and naturalized in many non-native regions. It is known to be invasive in Cuba, Asia, and parts of the Pacific. High-risk traits include its self-compatibility, tolerance of a broad climate range and soil conditions, toxicity to animals and humans, and its ability to reproduce prolifically by producing numerous tiny, grainlike, viable seeds[].

Known Hazards

The plant contains the toxic and highly addictive alkaloid nicotine. Widely used in all parts of the world as a stimulant, usually by smoking the plant or chewing it, in larger doses nicotine causes vomiting, diarrhoea, slow pulse, dizziness, collapse, and respiratory failure[].

Botanical References

Range

S. America - Bolivia

Habitat

Not known in a truly wild situation, it is the result of hybridisation between Nicotiana sylvestris and Nicotiana tomentosiformis[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual/Perennial
Height	1.20 m
Pollinators	Bees, Lepidoptera, Self
Self-fertile	Yes
Cultivation Status	Cultivated, Wild

Cultivation Details

Nicotiana tabacum is a plant of the seasonally dry tropics, where it is found at elevations from 800 - 1,800 metres[]. It can also be grown at lower elevations in the subtropics and temperate zone, succeeding at latitudes between 60°N and 40°S[]. It grows best in areas where the mean annual temperature falls within the range 15 - 30°c, but can tolerate 7 - 35°c[]. It prefers a mean annual rainfall of 500 - 750mm, tolerating 350 - 3,000mm[]. Plants are not very hardy in the temperate zone, though they can be grown as biennials in areas where winter temperatures do not fall below about -5°c[].
Prefers a well-drained deep rich moist soil in a sunny position[, ]. Prefers a pH in the range 5 - 6.5, but tolerates 4.5 - 7.5[].
A polymorphic species[].
The plant accumulates potassium[].
The plant has sweetly scented flowers that release most of their scent in the evening and attract moths[].
Plant requires more than 14 hours daylight per day in order to induce flowering[].

Edible Uses

A protein can be extracted from the leaves. It is an odourless, tasteless white powder and can be added to cereal grains, vegetables, soft drinks and other foods[]. It can be whipped like egg whites, liquefied or gelled and can take on the flavour and texture of a variety of foods[]. It is 99.5% protein, contains no salt, fat or cholesterol[]. It is currently (1991) being tested as a low calorie substitute for mayonnaise and whipped cream[].

An edible oil is obtained from the seed[].

The leaves have been dried and then chewed as a stimulant or made into snuff for sniffing, or smoked.
The leaves are manufactured into smoking tobacco (pipe-, cigar-, cigarette-tobacco, hardly any to snuff or chewing tobacco) by a highly developed industry[]. Although used extensively for recreational purposes, tobacco frequently causes pathological conditions and death[].

Medicinal

Tobacco has a long history of use by medical herbalists as a relaxant, though since it is a highly additive drug it is seldom employed internally or externally at present[, ]. The plant should be used with great caution[], when taken internally it is an addictive narcotic[]. The active ingredients can also be absorbed through the skin[].

The leaves are antispasmodic, discutient, diuretic, emetic, expectorant, irritant, narcotic, sedative and sialagogue[, , ]. Traditionally, the leaf has been taken internally as a cholagogue to calm the liver[].
They are used externally in the treatment of rheumatic swelling, skin diseases and scorpion stings[]. Wet tobacco leaves can be applied to stings in order to relieve the pain[]. They are also a certain cure for painful piles[]. A poultice of the leaves has been used to treat headaches[]. The juice of green tobacco has been used as an eyewash[]. The leaves are mixed with the stem and leaves of Rhabdadenia biflora to remedy the wound of stingrays[].
Nicotine tar is used to expel parasitic worms in the skin, such as Dermatobia hominis, and to repel Pulex[].

When used by tribal shamans, tobacco intoxication can cause a nicotine-induced cataleptic rigidity in which the practitioner's body becomes as stiff and straight as a wooden board. As such, tobacco is used as an hallucinogenic and psychoactive material to create a connection between the shaman and the spirits being consulted for healing instructions, in addition to the strictly medicinal reasons outlined above[].

A homeopathic remedy is made from the dried leaves[]. It is used in the treatment of nausea and travel sickness[].

Other Uses

All parts of the plant, apart from the seeds[]. contain nicotine, this has been extracted and used as an insecticide[, , ]. The dried leaves can also be used, they remain effective for 6 months after drying[]. The juice of the leaves can be rubbed on the body as an insect repellent[].

A drying oil is obtained from the seed[, ]. The seeds contain no nicotine and the refined seed oil can be used for illumination and in the oilpaint and varnish industries[].

Tobacco is an important plant in biotechnology and molecular biology studies. Transgenic tobacco plants are widely used for the study of molecular genetics and the transfer of genes relating to herbicides, virus, pest and stress resistance. It has the potential to be used for the production of pharmaceuticals and other chemicals through 'molecular farming'[].

Propagation

Seed - surface sow in a warm greenhouse about 10 weeks before the last expected spring frosts. The seed usually germinates in 10 - 20 days at 20°c. Keep the soil moist and pot up as soon as the plants are big enough to handle, planting them out after the last expected frosts.