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(tobacco), a genus of annual and perennial shrubs and herbaceous plants of the family Solanaceae. The leaves are entire, and the flowers are five-parted and variously colored. The fruit is a capsule with very small seeds. There are more than 60 species in America and Australia; two species occur in the USSR. The common tobacco (N. tabacum) and the small tobacco (N. rustica) are widely cultivated as narcotic plants; they are not found in the wild state. Other cultivated species are N. quadrivaevis and N. glutinosa. In some regions the local population smokes the leaves of wild species, including N. paniculata and N. silvestris. Species with large or fragrant flowers, for example, N. alata, N. sanderae, and N. suaveoleus, are cultivated as ornamentals.
The common tobacco, a perennial that is usually grown as an annual, has a rounded, erect, viscid-pubescent stem that reaches 2.5 m in height and is branching above. The alternate, petiolate or sessile leaves are oval, rounded, or elliptic; their coloration is green or, less frequently, yellow or yellow-green. The pink, red, or white flowers are gathered into cymose inflorescences at the ends of the main stems and lateral branches. The fruit is a capsule with numerous minute brownish seeds; 1,000 seeds weigh 60 to 80 mg.
The vegetative period of the tobacco plant is 135 to 170 days. The plant is thermophile: the optimum temperature for germination is 27°–28°C, and the optimum temperature for growth and development is 24°–28°C. The plant also requires a lot of moisture, especially when leafing is complete, and it uses much nutrient matter. The best soils are light and medium chernozems, sierozems, and chestnut soils.
The leaves are used in the manufacture of tobacco products, whose quality depends on the ratio of proteins and carbohydrates and on the content of nicotine and essential oils. The seeds contain 30 to 35 percent fatty oil, which is suitable for industrial purposes (lubricants).
Tobacco was grown in America long before it was discovered by Europeans. It was imported into Europe—first into Spain and Portugal and later into France, Germany, and Italy—in the late 15th and early 16th centuries; it was initially grown in Europe as an ornamental and medicinal plant. Tobacco was first cultivated in Russia at the beginning of the 17th century; the first tobacco plantations were established in 1716 at the village of Akhtyrka in the Ukraine. The plant’s cultivation in Asia (Turkey) dates back to the early 17th century.
Worldwide plantings of tobacco totaled 3.9–4.2 million hectares (ha) between 1961 and 1974. The largest plantings are in China, India, the USA, Indonesia, and Turkey. Tobacco is also grown in South America, Europe, West Africa, and Australia. The average yield of dry leaves between 1961 and 1974 exceeded 11.5 quintals/ha; the largest producer was the USA, where the yield was 21–23 quintals/ha.
Between 1961 and 1974, 150,000–170,000 ha were under tobacco cultivation in the USSR (Moldavia, the Ukraine, Transcaucasia, Tadzhikistan, Uzbekistan, Kazakhstan, Krasnodar Krai). The average yield of dry leaves was 11–15 quintals/ha. The best varieties for cigarette manufacture are Peremozhets, Ostro-list B-2747, Trapezond 1867, Amerikan 287-S, Samsun 417, and Diubek 44. The varieties Perevolochanets and Gavana 112 are among the best for cigar production.
The crop is grown in a rotation system by the transplant method. On 1 ha, 50,000–200,000 seedlings are set out in wide rows. Fertilizer is applied at a dose of 30–60 kg/ha N, 60–100 kg/ha P2O5, and 50–100 kg/ha K2O. Harvesting is done in five to eight stages. The leaves are placed in drying sheds and undergo fermentation at a temperature of 25°–30°C; fermentation involves complex biochemical changes in the tissues (decomposition of proteins, conversion of starch to sugar, a lowering of nicotine content, and an increase in the content of aromatic substances). The leaves are then dried in the sun or in special ovens. The stems are ground and plowed under.
Injurious pests of tobacco include the tobacco thrips, the tobacco fly, tobacco and turnip moths, wireworms, and false wire-worms. Common diseases include powdery mildew, black root rot, and tobacco mosaic.
REFERENCESLasareishvili, M. D., and P. V. Chikov. Agrolekhnika vysokikh urozhaev tabaka. Sukhumi, 1960.
Pevzner, L. M. Tabak i opyt ego vozdelyvaniia v Moldavii. Kishinev, 1963.
Eremenko, A. S., and D. I. Tsyndria. Krymskie tabaki. Simferopol’, 1965.
Leonov, I. P., A. G. Petrenko, and G. M. Psarev. Posobie dlia tabakovodov. Moscow, 1968.
Asmaev, P. G., and M. G. Zagoruiko. Sortovedenie tabaka i makhorki. Moscow, 1973.
I. P. LEONOV