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common name for a tall annual herb (Cannabis sativa) of the family Cannabinaceae, native to Asia but now widespread because of its formerly large-scale cultivation for the bast fiber (also called hemp) and for the drugs it yields.
..... Click the link for more information. ; marijuanamarijuana
drug obtained from the flowering tops, stems, and leaves of the hemp plant, Cannabis sativa (see hemp) or C. indica; the latter species can withstand colder climates.
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a genus of annual bast fiber plants of the family Cannabaceae. The genus has three very closely related species— hemp (Cannabis sativa), C. indica, and C. ruderalis. Hemp is grown for its fiber primarily in the USSR, India, and the countries of Western Europe; it grows wild in the USSR, Mongolia, Afghanistan, Pakistan, India, and China. C. indica is cultivated in several countries, including India, Iran, Turkey, and Syria, for its fatty seed oil, for marijuana, and for the narcotic hashish. Hashish is made from the plant’s foliage; marijuana, from the female flowers. C. indica also grows wild in Pakistan and Afghanistan. The species C. ruderalis is a pernicious weed that harms spring crops in the USSR (Western Siberia, Middle Asia, and the Volga Region). Many authorities consider these three species a single species. Varieties of hemp are divided into groups according to geographical location. The principal varieties in the USSR are the northern, middle Russian, and southern (the highest-yielding variety).
Hemp, an annual dioecious plant, is wind-pollinated. In Russia the male plant is known as poskon’ or zamashka and the female, as materka. The stems of young Cannabis plants are globose, soft, and covered with glandular hairs; as they mature, they become woody and faceted. The stems are 0.5–4 m tall and 8–30 mm thick. The plant has a taproot. The lobed leaves are green and have pink or dark violet midribs and petioles. The flowers of the male plant are in small loose panicles on the apex of the main and lateral shoots; the flowers of the female are in capitate inflorescences in the axils. There are some monoecious plants with male and female flowers. The fruit is a single-seeded nut, 1,000 of which weigh 12–22 g.
The growth and development period of Cannabis is 65–70 days (northern variety) and 140–160 days (southern variety). The rapidly growing shoots appear when the soil temperature is at least 8°-10°C. The young plants easily survive a frost of up to 5°C. The optimum temperature for growth and development is 20°-25°C. Cannabis needs moist soil, particularly during budding and flowering. It is also at this time that it requires the greatest quantity of fertilizer. The best soils for Cannabis are chernozems and drained peat bogs.
The female plant harvested during the initial stage of maturity and the male plant yield fiber, or hemp, from which fabric is made. The fibers of a female plant that is harvested for its seeds are used to make nautical cordage, twine, and sailcloth. The male plants yield 20–25 percent fiber from the dried stalks, and the female plants, 12–20 percent. The fruits of Cannabis plants contain 30–35 percent fatty oil, which is used in food and for industrial purposes. Cannabis oil cakes are valuable fodder. The garden variety of hemp (Cannabis sativa var. sinensis) has attractive bright foliage and is grown as an ornamental.
Cannabis is a very ancient crop. Its place of origin is thought to be Central Asia, where it was grown in the first millennium B.C. It has been grown in the USSR since the ninth century, when the hemp trade developed. Cannabis has been found in Europe only since the 16th century. In 1971 the area allotted to the cultivation of Cannabis throughout the world was approximately 580,000 hectares (ha), with an average fiber yield of 4.7 centners per ha. From 1965 to 1971, plantings of Cannabis in the USSR did not exceed 300,000 ha.
Fiber yield on leading farms is 11–12 centners per ha. Cannabis is sown mainly in the central chernozem regions of the RSFSR, in the forest-steppe and southern part of the Ukraine, and in Byelorussia, the Volga Region, the Northern Caucasus, and Western Siberia. Basically, selected varieties are cultivated, including Southern Maturing 6, Southern Cherkassian, and Krasnodar 35. Monoecious varieties have been bred. Because the male plant matures before the female, creating difficulties during harvesting, work is under way to develop varieties in which the two plants mature simultaneously.
Cannabis is cultivated in hemp fields and in rotation with other crops, the best being perennial herbs, potatoes, and sugar beets. Manure or compost (40–60 tons per ha) is applied during the late fall plowing or during replowing in the spring. Mineral fertilizers (30–120 kg/ha of pure nitrogen fertilizer, 30–100 kg/ha of phosphorus fertilizer P2O5, and 45–120 kg/ha of potassium fertilizer K1O) are applied during autumn plowing, during spring cultivation or replowing, or during sowing, with the seeds and the topdressing. Cannabis is sown when the temperature of the upper layer of soil is 8°-10°C, in rows spaced 15 or 7 cm apart. One hectare can be sown with 80–120 kg of seeds, usually planted 3–4 cm deep. The crops are kept free from weeds. When grown for a dual purpose, for fiber and seeds, there are two-stage harvests: during massive flowering the male plants are pulled out by hand, and the female plant is harvested when its seeds are mature by a hemp harvester (with subsequent threshing by a hemp thresher) or a hemp-harvesting combine (which also threshes). If the female plants are cultivated only for the fiber, the male and female plants can be harvested simultaneously, when the male begins to shed its flowers. After threshing, the plants are soaked in water; the hemp stock is then dried and turned into fiber.
Cannabis plants are most seriously damaged by the flea beetle Psylliodes attenuata, the stem borer Pyrausta nubilalis, the weed broomrape, and the fungus fusarium.
REFERENCESKonoplevodstvo. Edited by A. S. Khrennikov and la. M. Tollochko. Moscow, 1953.
Lashkevich, G. I. Konoplevodstvo na torfianykh pochvakh. Minsk, 1953.
Konoplia. Edited by G. I. Senchenko [et al.]. Moscow, 1963.
Zhukovskii, P. M. Kul’turnye rasteniia i ikh sorodichi, 3rd ed. Leningrad, 1971.
A. I. ARINSHTEIN