CULTIVATED FLAX (Linum usitatissimum L.)

Flax is an old cultural crop. In Mesopotamia it was grown as early as 6 thousand years B.B. Also ancient Egyptians could grow and spin flax; mummies of pharaohs were wrapped in about 200m log stripe of flax fabric that persisted to this day.

Importance and seed composition:

There are two basic types of flax according to utilization:

Len přadný has longer, thinner and very little branched stalks. The main raw material obtained are stalks which are processed to produce long fibres and tow (short fibres). Products such as fabric, bags, cotton strings, cigarette papers are manufactured from flax raw materials. Seeds are only a by-product, and are used for the manufacture of technical oil (paints, varnishes, lacquers, linoleum, artificial leather), flax extracted meal and cake can be used for livestock feeding. In this country přadný len prevails.

Len olejný has shorter and thicker stalks with branched flowers and a higher number of seed bolls. Flax seeds are used for foodstuff production and for technical purposes. Stalks are by-product. Fibres are coarser than in přadný flax and it is more difficult to weave. It can be processed to produce tow or used in the paper. In the world, this flay type prevails.

For human consumption, whole seeds or cake flour are used as an additive to pastry and other foodstuffs to increase their nutritional value and improve physical properties (vláčnost, slowing retardation of pastry drying off) as well as table oil. For animal nutrition, whole seeds and meal or oil cake are used. Seed husks are high in slimy polysaccharides that are released from scaled seeds are favourably influence the digestive tract.  They are suitable for young animals, females in late pregnancy and animals with digestive tract diseases. Linseed decoction can be used, too. Besides, linseed has lactogenic effects, increases hair luster and accelerates molting.

Linseed contains 30-36 % fat with high linolenic acid proportion, 20-23 % crude protein, 6-10 % crude fibre, 7-10 % nitrogen-free extract and 2-3 % minerals. It contains some undesirable substances, the most important being cyanogenic glycosides. From glycosides, there are the highest contents of linustatin, neolinustatin and linamarin. These are not toxic, but due to the influence of flax glucosidase or non-specific glucosidases from other feed components and due to the rumen microflora activity, HCN is released from them. HCN content must not exceed 250 mg/kg, if so, the seed is damaging to health. The main effect of HCN is cytochromoxidase inhibition, but it also effects other enzymes. Central nervous system and the heart are the most affected. The signs of intoxication are panting, insensibilization of peripheric organs, later there is laboured breathing, titanic cramps, paralysis and death. For seed detoxification for feeding purposes, a two step extraction first with hexane and then with methanol with added alkali is recommended.

 Cultivation requirements:

Optimum cultivation conditions for the flax are an altitude up to 450 m, light, sandy-loam soils with pH 5.5-7 and generally dryer climate. Flax is sown from the end of March to the end of April. In the cultivation-technological procedures and protection are similar to those of předný len. Harvest, however, is completely different because the product is not fibre but seed. Flax is harvested in full maturity by picker-shellers. Yields of stalk and seed are higher than in len přadný.