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flax,common name for members of the Linaceae, a family of annual herbs, especially members of the genus Linum, and for the fiber obtained from such plants. The flax of commerce (several varieties of L. usitatissimum) has been cultivated since prehistoric times (see linenlinen,
fabric or yarn made from the fiber of flax, probably the first vegetable fiber known to people. Linens more than 3,500 years old have been recovered from Egyptian tombs. Phoenician traders marketed linen in Mediterranean ports.
..... Click the link for more information. ). It was the major source of cloth fiber until the growth of the cotton industry (c.1800) and the competitive use of other fibers, such as jute. Flax has been transplanted from its native locales in Eurasia to all temperate zones of the world that provide a suitable habitat (a cool, damp climate) for its cultivation as a fiber plant; it is also grown in many tropical countries for its oil-bearing seeds. Flax plants grow to 4 ft (120 cm) in height and bear blue or white flowers that mature into bolls containing 10 seeds each. When grown for fiber, flax is sown densely to prevent branching and is gathered before maturity; for seed, it is sown sparsely and allowed to branch and fruit. To obtain the fiber, the stems, stripped of leaves, may be tied in bunches and immersed in warm water for a few days or in cool water for one or two weeks, or they may be spread out on grass and exposed to the dew and sun for several weeks. This process, called retting, permits bacteria to break down the woody tissues by fermentation and to dissolve by enzyme action the substances binding the fiber cells. After retting, the stems are washed and allowed to dry and then are scutched (beaten) to separate the fibers from other material and to crush the pith. A combing process (called hackling) removes any remaining nonfibrous matter. The fiber cells range in length from 1-2 to 2 in. (1.3–5.1 cm); the cell bundles (fibers) range from 12 to 36 in. (30–90 cm). Short, broken fibers are called tow and are used to make coarse fabrics and cordage; the long fibers are used for strong threads and fine linens. Flax fiber has also been used for such products as insulating material and writing and cigarette paper. The seeds are crushed to make linseed oillinseed oil,
amber-colored, fatty oil extracted from the cotyledons and inner coats of the linseed. The raw oil extracted from the seeds by hydraulic pressure is pale in color and practically without taste or odor.
..... Click the link for more information. , and the remaining linseed cakelinseed cake,
concentrated feed for livestock, prepared by pressing into cakes linseed from which most of the oil has been removed. The amount of oil remaining in the cake varies; the seed husks may or may not be removed. Linseed cake has a high protein value.
..... Click the link for more information. is used for fodder; dried flaxseed has been used in various medicinal preparations. Flax is classified in the division MagnoliophytaMagnoliophyta
, division of the plant kingdom consisting of those organisms commonly called the flowering plants, or angiosperms. The angiosperms have leaves, stems, and roots, and vascular, or conducting, tissue (xylem and phloem).
..... Click the link for more information. , class Magnoliopsida, order Linales.
any annual and perennial herb or shrub of the genus Linum of the family Linaceae. There are more than 200 species, growing primarily in the subtropical and temperate latitudes. Over 40 species are found in the USSR. The plant most often cultivated for fiber and seeds is common flax (Linum usitatissimum), of which there are the following groups of varieties: elongata, intermedia, brevimulticaulia, macrospermum, and prostrata. Common flax probably derives from L. angustifolium, which was cultivated in the past in subtropical mountain regions (India, China, the Mediterranean region, and Transcaucasia). In the USSR, L. usitatissimum var. elongata is cultivated for fiber; var. intermedia and var. brevimulticaulia, which are grouped under one common name, are grown for the oil from their seeds (linseed oil). L. crepitans grows as a weed in fields of cultivated flax. Some species, including flowering flax (L. grandiflorum), L. flavum, and L. austriacum, are grown as ornamentals.
L. usitatissimum var. elongata, an annual plant, has one stem when grown in dense plantings. It has a taproot with weakly developed lateral branches. The cylindrical stem, which is yellow in color when mature, reaches a height of 70–125 cm and a thickness of 0.8–2.0 mm. The leaves are sessile and lanceolate; the inflorescence is an umbellate raceme. The flowers are pen-tamerous and have a pale blue (rarely white or pink) corolla; they measure 15–24 mm in diameter. The fruit is a globose, indehiscent capsule; it contains ten seeds and is divided by internal septa. One to three capsules mature on each plant; in thinned plantings up to 12 can be obtained. The seed is flat, ovate, shiny, and usually brown (sometimes yellow); it becomes slimy when soaked in water. One thousand seeds weigh 3.5–6.6 g. The period of growth and development of L. usitatissimum var. elongata is between 75 and 90 days. The seeds begin to sprout at a temperature of 3°–5°C. The young shoots can withstand a temperature no lower than 3.5°–4.0°C. The optimum temperature for growth and development is 15°–18°C; overcast weather is also desirable. This variety is moisture-loving, particularly during budding and flowering. The fertilizer for 1 centner of air-dry harvested material (straw and seed) is 1.3–1.5 kg N, 0.37–0.52 kg P2O5, and 0.62–1.37 kg K2O. The best soils are medium and light weakly podzolized loams with a pH of 5–6.
The flax fiber (the stem contains 20–28 percent fiber), which consists of elementary fibers, is made into thread and then into linen. The tow is used as fuel and in the production of thermal insulation materials and plasterboard. The seeds contain 35–37 percent oil.
L. usitatissimum var. elongata has been cultivated in Georgia (Colchis), Egypt, and several other countries for several thousand years. This variety was known in antiquity in the European part of the USSR. Scientists found seeds of cultivated flax, which they succeeded in sprouting, pieces of thread, and imprints of fabric on ceramic objects in excavations of a pile-dwelling settlement on the Modlona River in Vologda Oblast that belonged to the beginning of the second millennium B.C. In the tenth to 13th centuries flax was distributed throughout Rus’. In the 13th to 16th centuries, Novgorod and Pskov were the principal centers of flax production and trade. By the beginning of the 19th century flax production was developed in almost all the provinces of the nonchernozem zone of European Russia. In 1860 L. utatis-simum var. elongata was sown on 650 hectares (ha) of land, and between 1905 and 1913, on 1 million ha.
In 1971 more than 1.5 million ha of this variety were sown in the world, particularly in the USSR, Poland (98,000 ha), France (43,000 ha), and Rumania (40,000 ha); var. elongata is also widely cultivated in Czechoslovakia, Bulgaria, Argentina, the German Democratic Republic, and several other countries. The world gross fiber yield is 648,000 tons, and the average harvest is 4.2 centners per ha. In the USSR in 1971 plantings of var. elongata occupied 1.26 million ha, with a gross fiber yield of 450,000 tons and an average harvest of 3.6 centners per ha.
In the USSR var. elongata is cultivated primarily in the non-chernozem zones of the RSFSR, the Ukraine, and Byelorussia, and the Baltic republics. Several strains of Soviet selection are cultivated; in 1972 there were 20 regionalized strains. The most widely cultivated strains are Svetoch, L 1120, Tomsk 10, Tomsk 9, I 9, VNIIL 11, Shokin, and Spartak.
L. usitatissimum var. elongata is grown in a system of crop rotation; the best rotations are with perennial grasses, fertilized winter crops, potatoes, and a mixture of vetch and oats. The highest fiber yields are obtained by applying a complete mineral fertilizer (kg/ha): 20–45 N, 40–90 P2O5, and 60–120 K2O. Manure is applied to the crop that precedes the flax. The seeds are sown in well-worked soil early in the season, when the soil has a temperature of 7°-8°C; they are planted in narrow-row drills (7–8 cm between rows). The seeds are placed at a depth of 1.5–3.0 cm; the average quantity of seed required is between 100 and 150 kg/ha (depending on the variety).
Care of the crop includes fertilization, the destruction of crust, and controlling weeds, diseases (fusarium wilt, rust, polysporo-sis, anthracnose, pasmo), and pests (Aphthona euphorbiae, Thrips lini, Laspeyresia dorsana, gamma moth). Flax is harvested when it reaches the early yellow ripeness. After harvesting, the plants are threshed. The stems are given a primary treatment (retting or steaming, breaking, and scutching) to separate the fiber. L. usitatissimum var. elongata is one of the most labor-intensive crops. Soviet industry has produced a number of machines that significantly reduce the labor and bring progressive technology to the raising of flax.
A. R. ROGASH
Oil flax, an annual plant, usually has one stem when planted in dense plantings. The root system is more developed than that of L. usitatissimum var. elongata. The branching stem is 20–70 cm tall. The structure of the leaves, inflorescences, flowers, and capsules resembles that of var. elongata (the capsules of oil flax are larger). One thousand seeds weigh up to 13 g. The period of growth and development is up to 150 days. This variety requires less moisture than var. elongata, but it needs more heat, especially during ripening. The best soils for growing oil flax are chernozems and chestnut soils.
The seeds contain 35–52 percent fatty oil, which like the oil of var. elongata is used to make lacquers, varnish, paints, linoleum, and other products; the oil is also used in food. Flax oil cakes are a concentrated feed. In medicine linseeds are used externally as a poultice and internally as a protective and emollient; linseed oil is used in the preparation of ointments and unctions. The straw contains 10–15 percent fiber, which is suitable for making sacking, tarpaulin, and string.
Oil flax has been grown in the USSR since ancient times. The Northern Caucasus is an old flax-growing region; at the end of the 19th century approximately 500,000 ha of oil flax were under cultivation. In 1971 more than 6 million ha of oil flax were sown, predominantly in India, the United States, Canada, the USSR, and Argentina; the world gross yield of linseeds was 2,878,000 tons, with an average harvest of 4.7 centners per ha (7.5 centners per ha in the Ukraine). The principal oil flax-growing regions of the USSR are Kazakhstan, Western Siberia, the Volga Region, the Ukrainian steppe, the Northern Caucasus, and the central Black Sea region. Strains of this variety include Voronezh 1308, Sibiriak, and VNIIMK 5237; in 1972 there were 18 regionalized strains. The best preceding crops are spring wheat (on land that has lain fallow), perennial grasses, maize, and a vetch and oats mixture. The proper mixture of mineral fertilizers (kg/ha) is 30 N, 45–60 P2O5, and 30–40 K2O. The seeds are sown in narrow-row drills (7–8 cm between rows) and wider drills (15 cm between rows). The seeds are planted at a depth of 3–7 cm; the average seeding is 50–60 kg/ha. Oil flax is harvested when 75 percent of the capsules are ripe.
O. I. RYZHEEVA
REFERENCESMaslichnye i efiromaslichnye kul’tury. Edited by V.S. Pustovoit. Moscow, 1963.
L’novodstvo. Moscow, 1967.
Severnomy shelku—novuiu tekhnologiiu proizvodstva. Moscow, 1967.
Rogash, A. R. “O selektsii l’na-dolguntsa v SSSR.” In Dostizheniia ote-chestvennoi selektsii. Moscow, 1967.
Rukovodstvo po selektsii i semenovodstvu maslichnykh kul’tur. Moscow, 1967.