In this essay we will discuss about:- 1. Origin and Distribution of Linseed 2. Area and Production of Linseed 3. Climate, Soils and Tillage 4. Varieties and Seasons 5. Seeds and Seeding 6. Nutrient Management 7. Cropping Systems 8. Water Management 9. Weed Management 10. Harvesting 11. Quality Considerations.
Contents
- Origin and Distribution of Linseed
- Area and Production of Linseed
- Climate, Soils and Tillage of Linseed
- Varieties and Seasons of Linseed
- Seeds and Seeding of Linseed
- Nutrient Management for Linseed
- Cropping Systems of Linseed
- Water Management for Linseed
- Weed Management for Linseed
- Harvesting of Linseed
- Quality Considerations of Linseed
1. Origin and Distribution of Linseed:
Cultivation of flax dates back to more than 500 years. Ancient Greeks and Romans cultivated flax for fibre and seed and established linen industry. Wearing of linen cloth was considered to be a sign of aristocracy and the gleaming whiteness of linen as a symbol of purity.
There is lot of controversy regarding origin of linseed. As per Vavilov, cultivated annual linseed probably originated from India, Ethiopia or Iran. The possibility of its introduction into India from Asiatic center of origin has also not been ruled out. Polyphytic origin of Indian linseed seems to be more logical.
Linseed is cultivated in almost all the countries in the world. Major producers are Canada, Argentina, USA, Poland, Uruguay, Romania, Ethiopia, USSR, China and India. In many European countries, it is mostly grown for fibre.
In the USSR, it is grown for seed and in America there is a shift from seed to fibre. In almost all the African countries, it is largely grown for seed. In the recent past, in almost all the countries, there is a shift in linseed cultivation from fibre to seed.
2. Area and Production of Linseed:
During 2003, the area under linseed in the world was 2.46 M ha with a production of 2.09 M t and productivity of 0.851 t ha-1. Tunisia has the highest productivity (2136 kg ha-1). Among the major linseed producing countries, China has the highest productivity (1130 kg ha-1) followed by Argentina (885 kg ha-1). In India, linseed is cultivated in an area of 0.34 M ha with a production of 0.15 M t accounting for a productivity of 440 kg ha-1.
India ranks first in terms of area under linseed and third in world production. Among the oilseed crops grown in India during rabi, linseed is next in importance to rapeseed and mustard in area and production. It is largely cultivated in MP, Chhattisgarh, UP and Bihar. MP ranks first in area (0.12 M ha) and production (0.05 M t). However, productivity is highest in Bihar (848 kg ha-1) followed by Assam (500 kg ha-1).
Linseed or seed flax (Linum usitatissimum) is one of the oldest cultivated crops grown for seed and fibre. In India, it is grown mainly for seed to extract oil. Linseed straw produces fibre of good quality. India ranks third in linseed production in the world. All parts of linseed plant are utilised for various purposes either direct or after processing.
3. Climate, Soils and Tillage of Linseed:
Climate:
Linseed is a cool season crop and adapted to the same climate as that of wheat crop. It is confined to sea level or lower elevations (600 m) and plains. As a seed crop, it can be grown at higher altitudes also. The minimum temperature regime is 10°C while the maximum is 38°C. The seed crop needs about 25°-30°C during germination and vegetative phase and 15°-20°C during seed formation. The fibre crop requires still lower temperature and high humidity.
Linseed is, generally, grown where annual precipitation rages from 500 to 800 mm. A well distributed rainfall of 450 to 500 mm is adequate for optimum yield. Drought and high temperature (32°C) during and after flowering stage reduce the yield, oil content and oil quality.
Soils and Tillage:
The crop makes good growth on well drained, moderately deep silty loam, clay loam and silty clays. Light soils are not suitable, especially in regions of low rainfall. The crop is also grown on rice soils and constitutes a major cropping system with rice. The crop can tolerate soil acidity to some extent but ideal soil pH is 6. It is more sensitive to salinity than most field crops and the fibre and oil content decreases at EC of 6.1 dS m-1.
Land preparation for linseed is similar to that for a wheat crop. Land should be ploughed two to three times followed by 2-3 harrowings. To conserve moisture, it is necessary to harrow the soil after each rain. When grown as broadcast crop in standing rice (relay cropping), there will not be any preparatory tillage.
4. Varieties and Seasons of Linseed:
Varieties:
High yielding varieties recommended for different states are given in Table 16.1.
Seasons:
Linseed is purely a rabi crop in India. Sowing from October to mid-November is ideal for high yields. In Madhya Pradesh and Uttar Pradesh, sowings up to middle of October appears to be optimum. Early sowing should be preferred to minimise the incidence of powdery mildew, rust and bud fly. Optimum sowing time for major linseed growing states is given in Table 16.2.
5. Seeds and Seeding of Linseed:
The seed must be treated with Carbendazim at 2 g kg-1 or Thiram at 3 g kg-1 against seed born diseases.
Seed Rate:
Seed rate depends on planting method, soil fertility status and the variety. In general, it varies from 20 to 40 kg ha-1. However, Dastur and Bhatt (1965) advised a seed rate of 10 kg ha-1 for most situations. Optimum seed rate varies from 10 to 15 kg ha-1 for small seeded varieties and from 20 to 25 kg ha-1 for bold seeded varieties. Low plant population results in more number of branches.
As such, it is desirable to have higher plant population for quality fibre. Broadcast crop require about 40 kg ha-1 compared with 30 kg ha-1 for drill sown crop. The optimum seed rate for dual purpose varieties is 25 kg ha-1. Irrigated crop requires relatively less seed rate (25 kg ha-1) compared with rainfed crop (30 kg ha-1).
Based on the results of experiments, the following seed rates are considered optimum under most situations:
1. Broadcasting: 40 kg ha-1 (rainfed).
2. Drilling: 30 kg ha-1 (rainfed).
3. Broadcasting: 35 kg ha-1 (irrigated).
4. Drilling: 25 kg ha-1 (irrigated).
5. Duel: 25 kg (all situations).
In general, a plant population of 4 lakh ha-1 is optimum for dual purpose varieties and 5 lakh ha-1 for other varieties.
Spacing:
For a sole crop of linseed, row spacing varies greatly from place to place. Based on the experimental results, optimum row spacing appears to be 25 cm under most situations.
Recommended row spacings for different states are given in Table 16.3:
Method and Depth of Seeding:
Usually, linseed is sown by broadcasting in traditional areas. However, line seeding with recommended spacing using seed drill pay rich dividends. Drill sowing ensures even distribution of seed and its uniform placement leading to adequate stand establishment.
Under ideal soil moisture condition, quick germination is obtained when the seed is sown 3 cm deep. In drylands, seeding depth may be up to 4 cm, if soil moisture in surface soil is inadequate for seed germination. A rain immediately after seeding leads to soil crust formation. Under such situation, a light harrowing, without disturbing the deep soil, is necessary for emergence. Thinning, if necessary, may be completed within 15 days after emergence.
6. Nutrient Management for Linseed:
Linseed usually responds well to residual soil fertility than direct application. Fertiliser application is justified only when there is evidence of a soil deficiency in one or more of the major nutrients. Linseed of 1000 kg removes approximately 55 N, 12 P2O5 and 40 K2O kg ha-1. Nitrogen deficiency is the most common nutritional disorder in linseed.
NPK Requirements:
Linseed crop responds to fertilisers depending on soil moisture availability. Under rainfed conditions, a dose of 40 N, 20 P2O5 and 20 K2O kg ha-1 is optimum. However, majority of farmers are not applying potassium fertilisers. For an irrigated crop, the recommendation is 90 N, 40 P2O5 and 30 K2O kg ha-1.
Time and Method of Application:
Under irrigated conditions, half of the nitrogen along with lull dose of phosphorus and potassium must be applied by placement (drilling) at seeding. The remaining half of nitrogen has to be applied 35 DAS at the time of first irrigation.
7. Cropping Systems of Linseed:
There has been a traditional belief that linseed should be grown on the same soil once in several years since it makes the soil so called linseed sick. The crop has been regarded as robber crop or poisoner crop of soil. However, it is not so. Experimental evidence stresses the need for crop rotation for optimum yield of linseed. Linseed is usually cultivated in rotation with sorghum, maize, pearlmillet, groundnut and cowpea.
Intercropping:
Under rainfed conditions, linseed is intercropped with cereals, pulses and oilseed crops as indicated below:
Sequence Cropping:
In northern parts of the country, the most common sequence is rice-linseed followed by maize- linseed and fallow-linseed. In central part of the country, sorghum-linseed is common followed by fallow-linseed. If rains are delayed for sorghum, a pulse crop is grown during rabi followed by linseed.
Pyra, Utera or Relay Cropping:
This is the best practice for utilising the residual soil moisture in rice fields where tillage after rice is difficult. Linseed is broadcast in standing kharif rice crop when the rice crop is between flowering and dough stage or 10-12 days before the harvest of rice crop. Linseed ulitises the residual fertility of manures and fertilisers applied to rice crop. Usually, one manual weeding is done after the harvest of rice.
Crack system of sowing linseed is a new method followed in areas where sufficient water is available. In this method, 5 cm deep cracks are allowed to develop in the field when the rice crop is at boot leaf or panicle initiation stage and the field is watered. After maintaining standing water for about a week, linseed is broadcast in the standing rice crop. This method gives about 50 per cent higher linseed yield without any adverse effect on rice yield.
8. Water Management for Linseed:
Linseed is, generally, cultivated as an un-irrigated crop. Under such situations, bold seeded and deep rooted varieties are grown. Under irrigation, small seeded and shallow rooted varieties are preferred. Hence, frequent light irrigations are more ideal and economical than heavy irrigations at longer intervals.
Critical Stages for Irrigation:
If winter rains fail, one or two supplemental irrigations are given, depending on availability of irrigation water. Flowering and seed development stages are critical stages for irrigation. Yield can be doubled if two irrigations are given, the first at 35 DAS and the second 65 DAS. However, three irrigations (35, 55 and 75 DAS) will be very effective for economic yield of linseed.
Scheduling Irrigation:
Systematic work on scheduling irrigation to linseed is limited. From the limited available information, it is evident that scheduling irrigation at 50 per cent DASM appears to be ideal for linseed crop. Scheduling irrigation at an IW/CPE ratio of 0.6 can also be followed. Depending on the weather and duration of the variety, water requirements vary from 450 to 600 mm. The crop is, generally, irrigated following check basin method of surface irrigation.
9. Weed Management for Linseed:
Linseed crop, due to its slow initial growth, is a poor competitor with weeds. The critical period for weed competition is the first 30 DAS.
Cultural Management:
Adequate tillage prior to seeding can minimise the weed infestation. If the seed is drilled with rows spaced 30 cm apart, two intercultivations at 20 and 35 DAS with a manual weeding is ideal to minimise the loss due to weeds.
Use of Herbicides:
In general, herbicides for weed control in linseed may not be economical due to poor crop yield under rainfed conditions. If necessary, Fluchloralin (1.0-1.5), Pendimethalin (1.0-1.5) or Alachlor (1.0-1.5) can be used for weed control in linseed crop.
10. Harvesting of Linseed:
Harvesting:
The crop may be harvested when the leaves are dry, capsules turned brown and the seeds have become shiny. If the fibre is also desired, harvesting should be done at the physicalogical maturity, when the crop is still green. The crop is, generally, harvested in March-April by cutting the plants close to the ground with sickle or by pulling the plants. Harvested crop is left in the field for few days for sun drying.
Threshing is by beating the dried plants with sticks or by trampling under the feet of cattle. The seed is separated from chaff by winnowing.
11. Quality Considerations of Linseed:
Seed Composition and Oil Quality:
Linseed contains 20-24 per cent proteins, 37-42 percent oil and 15-29 per cent carbohydrates, 5-9 per cent crude fibre and 2-4 per cent ash. Normal linseed oil is a drying oil and is unfit for edible purpose because of short self-life.
Linseed oil is unique among vegetable oils in that it contains more than 50 per cent linolenic acid. It sets into a hard vitreous film when applied as a thin film and exposed to air. Linseed oil is used in paints, exterior stains and industrial coolings. It is also used in printing ink, linoleum etc..
Oilcake:
Linseed protein (20-24%) is deficient in lysine and methionine as in any other oilseed. The expeller cake contains 30 per cent proteins, 7 per cent fat and 42 per cent carbohydrates. The meal is a valuable protein source to poultry and ruminants.
Linseed contains several undesirable compounds such as mucilage, phytic acid, cyanogenic glucoside and goitorogen, which limit its use as animal feed.
Linseed Fibre:
Linseed fibre, extracted from stem, could be spun and woven in to cloth. The fibre is stronger, more durable and more resistant to moisture than cotton or wool. Therefore, it is used in gloves, footwear, netting and sportswear. It is also used in paper and textile industry.
After fibre extraction, the remaining material can be used as pulp for manufacturing straw boards, writing paper and parchment paper. Linseed fibre is used for the manufacture of cigarette paper.