Linseed: Uses, Benefits, and Medicinal Properties

Linseed (Linum usitatissimum L.)

Family: Lineaceae Its species name usitatissimum was derived from Greek word, meaning most useful and genus name linum, meaning fibre, popularly called linen. It is used as fibre crop to manufacture linen clothes. Linseed, also called flax has two important uses- fibres and edible oil. It is called as flax, when it is grown for oil seed purpose, it is called as linseed. When it is grown for dual purpose such as oil and fibre then it is called as flax. Earlier it is used to produce linen (it is a fabric material). Fibres are used to make rope, cloth. In India, oil types are grown, while in European countries, flax is grown for fibres.

Uses: Linseed has number of medicinal uses, industrial uses, besides oil meal being used as cattle feed. Its oil is used in the preparations of paints and varnishes as drying oil, printing inks and in the manufacture of linoleum. The seeds have 35-45% oil contents, 28% fibre and 20% protein. Flax seeds are consumed directly, roasted, or powdered before consumption or even sprouted and consumed or seeds are crushed and linseed oil is extracted and used for many culinary and bakery applications. Linseed oil is rich in unsaturated fatty acid, linolenic acid (51%) and small content of saturated fatty acids, like palmitic acid (7%) and stearic acid (3-4%). Linseed /flax oil is remarkably resistant to rancidity (oxidation of oil by the exposure to air) and is stable under room temperatures.

Flax fibres, which are extracted from stem (called bast fibres), are three times stronger than cotton fibres. Flax fibres are also useful to make ropes, canvas, and high quality papers (used as paper for currency notes).

Flax seeds have certain medicinal uses also. Its seeds contain high levels of dietary fibre as well as lignans, an abundance of micronutrients and omega -3 fatty acids. Consumption of flax seeds may lower cholesterol levels. Flax seeds may also lessen the severity of diabetes by stabilizing the blood sugar levels. The linseed oil is not used as cooking medium like other vegetable oils. Consuming large amounts of flax seed may impair the effectiveness of certain oral medications, due to its fibre content, and may have adverse effects due to its content of neurotoxic cyanogen glycosides and immuno suppressive cyclic nonapeptides. One of the main components of the flax is lignan, which has plant estrogen as well as antioxidants ( flax contains up to 800 times more lignans than other plant foods contain).

Classifications according to Vavilow Bold seed fibre types: Mainly grown in Europe and north America It is tall growing , long duration of 160-180 days Seeds are brown or black Origin is Mediterranean Small seeded types: Dwarf type Mainly grown in Asia and Africa Short duration of 140-150 days Originated in western Asia, Afghanistan Brown shining seeds

Origin Small seeded oil type linssed was originated in South Western Asia Bold seeded fibre type flax was originated in Mediterranean region.

Area and distribution At global level, linseed is a minor crop both in respect of its oil and its fibre. It is grown over an area of 2.48 million hectare with a productivity of 826 kg/ha. India leads in its area. But it is also cultivated on a large area in China, Russia, Canada and Kazakhstan. In India, Madhya Pradesh alone cultivate half of the total area, while other states contributing to large area are Uttar Pradesh and Maharashtra.

Climate: It is cool season crop, mostly grown in post monsoon season along with other intercrops. It requires cool/humid climate for vegetative growth and dry cool weather for maturity. It is susceptible to frost. Less than 30C kills the crop and more than 320C reduces the seed yield. Soil type: Itis grown in any fertile soils but clay soil is suitable very well. In India it is grown in sandy loams, clay loam soil. Higher soil pH reduces the oil content so it should be less than 7.0.

Botanical Description of Plant Linseed belongs to the family Lineacea, and grows as perennial or annual, depending on the varieties, conditions and types of cultivation. It is an erect, herbaceous annual with branches as corymb. Two types of L. usitatissiumum are cultivated- Linseed type, grown for oil extracted from the seed, is a relatively short plant which produces many secondary branches, Flax type, grown for the fibre extracted from the stem, which is taller and is less branched.

Root: Linseed has a short tap root with fibrous branches, which may extend 90- 120 cm in light soils. Leaves are simple, sessile, linear- lanceolate with entire margins, and are borne on stems and branches. Flowers: The infloresence is a loose terminal raceme or cyme. Flowers borne on long erect pedicels , five stamens, and a compound pendacarpellary pistil, each separated by a false septum. Fruit is a capsule, composed upto 10 seeds. The seed is oval, lenticular, 4-6 mm long with a smooth, shine surface, brown to light-brown in colour. Seeds contain 35-45% oil content 20-25% protein.

Cropping systems Linseed is grown in rotation with many kharif crops like sorghum, pearl millet, groundnut, cowpea and soybean. It is also intercropped with the crops like barley, wheat, gram and mustard. More popularly, in the Eastern part of India, it is grown as relay crop, where the linseed is grown by broadcasting the seeds in between standing crop of paddy as uteta or praire crop.

Production practices Land preparation: One deep ploughing with MB plough followed by 2-3 harrowing and final levelling ensuring fine seed bed is required for sowing linssed. Before final levelling, 4-5 tons manure/hectare needs to be applied.

Manure and Fertilizers requirement Application of manure 15 days in advance of sowing is essential. Application of fertlizers supplying 50 kg N, 40 kg P2O5 and 40 Kg K2O per hectare is sufficient. Entire dose of fertlizers is applied at the time of sowing. Sowing: sown as an intercrop with a row spacing of 25 to 30 cm Seed rate: 20-30 kg/ha for sole crop, 8-10 kg/ha for intercropping, 40-50 kg/ha for utera cropping and broadcasting. Water management: 95 % of the crop is grown as rainfed/unirrigated crop. But the crop responds well to 1-2 irrigations (after 30-40 days and second before flowering). It is a long duration crop; it requires water of 45-55 cm and flowering and seed maturity are the critical period for irrigation.

Intercrops; Wheat, barley, chick pea, safflower and mustard Cropping system; Sorghum-linseed, groundnut-linseed, pearl millet- linseed Utera crop/paira cropping system It is relay cropping system where before harvest of paddy linseed seeds are broadcasting between paddy rows, it helps to better utilization of stored moisture. It is commonly produced in UP, Orissa, West Bengal and HP. Varieties suitable for Utera; Himalini and Surabhi Varieties suitable for rainfed; Kiran, Sheethal and Swetha For irrigation; Jawahar-53

Weed management As linseed is poor competitor, the crop is likely to be lost, if inter-cultication is not done after 20-25 days as well as 40-45 days of sowing. Thinning operation after 2 weeks is also essential to retain seedlings every 10-15 cm. If necessary, one hand weeding may be provided. Generally, herbicides are not used, looking to its low yield potential.

Pest and diseases: Rust Wilt Powdery mildew Midge Leaf miner Cut worm

Harvesting and yield Crop matures in 130-140 days. The indication of maturity is provided by yellowing of stem and withering of leaves. Entire plant is cut and bundled and transferred to thresing yard, where they are beaten by sticks and the seeds are separated. Yield: Light soil; 4-6 q/ha (seed) Heavy soil; 10-12 q/ha (seed) Dual purpose linseed varieties; Light soil; 8-10q/ha (seed) and 8-10t fibre/ha Heavy soil; 3-4 q/ha (seed) and 12-15 t fibre/ha.