Linseed / Flax (Linum usitatissimum L.)

1. Origin and History

• Origin: Mediterranean region (Turkey, Greece, Egypt) – secondary centres in South-West Asia & India.
• Cultivated for >5000 years for fibre (linen) and oil (linseed oil).
• Spread to India, China, and Europe in ancient times.

2. General Information

• Family: Linaceae.
• Known as dual-purpose crop →
  • Linseed: for oil.
  • Flax: for fibre.
• Oil content: 33–40% (drying oil).
• Protein: 20–25%.
• Seed contains α-linolenic acid (ALA ~50–55%) → omega-3 fatty acid.
• Duration: 100–150 days.
• In India, grown mainly as Rabi oilseed crop.

3. Area, Production & Distribution (India, 2023)

• Area: ~0.3 million ha.
• Production: ~0.15 million tonnes.
• States: Madhya Pradesh, Chhattisgarh, Uttar Pradesh, Maharashtra, Bihar, Odisha.
• India is one of the top 5 producers globally.

4. Climatic Requirements

• Cool, dry climate (Rabi crop in India).
• Temperature: 10–25°C optimum.
• Rainfall: 400–600 mm (low to medium rainfall zones).
• Sensitive to high humidity & continuous rain → promotes rust & blight.
• Best suited for temperate & subtropical regions.

5. Soil

• Well-drained loams & clay loams with good organic matter.
• Optimum pH: 6.0–7.5.
• Tolerates slightly acidic to neutral soils.

6. Varieties

• Linseed (oil type): T-397, Neelum, Pusa-2, Surabhi, Nagarkot, Indira Alsi-32.
• Dual purpose: Padmini, Rashmi.
• Fibre type (flax): not common in India (grown in Europe, Canada).

7. Agronomy (Cultural Practices)

• Season: Rabi (October–November sowing).
• Seed rate:
  • Broadcast: 30–40 kg/ha.
  • Line sowing: 20–25 kg/ha.
• Spacing: 30 cm × 10 cm.
• Sowing depth: 2–3 cm.
• Fertilizer requirement:
  • N: 40–60 kg/ha.
  • P₂O₅: 30–40 kg/ha.
  • K₂O: 20 kg/ha.
• Irrigation: Mostly rainfed, but 2–3 irrigations improve yield.
  • Critical stages: Crown root initiation (20 DAS), flowering, seed filling.

8. Weed Management

• Critical period: 20–40 DAS.
• 2 hand weedings (20 & 40 DAS).
• Herbicides:
  • Pendimethalin @ 1.0 kg a.i./ha (PE).
  • Isoproturon @ 0.75 kg a.i./ha (early POE).

9. Pests & Diseases

• Insect pests:
  • Gall midge (Dasyneura lini).
  • Aphids.
• Diseases:
  • Rust (Melampsora lini) – most serious.
  • Alternaria blight.
  • Wilt (Fusarium oxysporum).
• Management: resistant varieties, seed treatment, crop rotation, fungicides (Mancozeb, Propiconazole).

10. Quality Components

• Oil content: 33–40%.
• Unique feature: Drying oil (high iodine number ~180).
• Fatty acids:
  • α-linolenic acid (ALA): 50–55%.
  • Oleic acid: 15–20%.
  • Linoleic acid: 12–15%.
  • Saturates (palmitic + stearic): ~10%.
• Nutraceuticals: Rich source of omega-3 fatty acids, lignans (anticancer).

11. Industrial & Food Uses

• Linseed oil: paints, varnishes, linoleum, waterproof fabrics, printing inks, soaps.
• Food: seeds as health food (flaxseed in bakery, cereals, nutraceuticals).
• Oilcake: cattle feed (after detoxification).
• Fibre (flax): linen fabric, ropes, mats.

12. Economics

• Low-input, suitable for rainfed regions.
• B:C ratio: ~1.5 under rainfed, ~2.0 under irrigated improved management.

13. Post-harvest Technology

• Harvest when capsules turn brown and seeds rattle.
• Harvesting is manual or by sickle.
• Threshing: beating or threshers.
• Dry seeds to ~8% moisture for storage.

14. Important MCQ Facts (Quick Recap)

• Botanical name: Linum usitatissimum L.
• Family: Linaceae.
• Origin: Mediterranean.
• Oil content: 33–40%.
• Protein: 20–25%.
• Unique component: α-linolenic acid (50–55%), drying oil (iodine value ~180).
• Seed rate: 20–25 kg/ha (line sowing).
• Spacing: 30 × 10 cm.
• Critical irrigations: CRI, flowering, seed filling.
• Major pest: Gall midge.
• Major disease: Rust.
• Special note: Dual-purpose crop → oilseed & fibre (flax).