Castor (Ricinus communis L.)

1. Origin and History

• Origin: Africa (Ethiopia / East Africa considered primary centre).
• Cultivated since ancient times → seeds found in Egyptian tombs (4000 years ago).
• Spread to India, China, Mediterranean region.
• India is today’s largest producer and exporter of castor seed & oil.

2. General Information

• Belongs to Euphorbiaceae family.
• Only major commercial species: Ricinus communis L.
• Oil content: 45–50%.
• Protein: ~18–20%.
• Special oil component: Ricinoleic acid (~90%) → unique hydroxylated fatty acid.
• Crop duration: 120–240 days (depending on variety & season).
• Nature: Deep-rooted, drought tolerant, wide adaptation.
• Known as “wonder industrial oilseed”.

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

• Area: ~1.2 million ha.
• Production: ~1.7 million tonnes.
• Productivity: 1400–1500 kg/ha.
• States: Gujarat (75% area & >80% production) > Rajasthan > Andhra Pradesh > Telangana > Karnataka.
• India’s status: No. 1 in the world (both production & export).

4. Climatic Requirements

• Grows well in tropical & subtropical regions.
• Temperature: 20–27°C optimum; sensitive to frost.
• Rainfall: 500–750 mm well-distributed.
• Drought tolerant, but sensitive to waterlogging.
• Photoperiod sensitive: Short days → promote female flowers; long days → more male flowers.

5. Soil

• Wide adaptability: sandy loam to clay loam.
• Best: Well-drained light to medium black soils.
• pH: 6.0–7.5 (neutral to slightly alkaline).
• Does not tolerate heavy clay & waterlogging.

6. Varieties / Hybrids

• Varieties: Aruna, GAUCH-4, VIJAYA, DCS-9, GCH-4.
• Hybrids: GCH-5, GCH-7, DCH-177, DCH-519 (commercially popular).
• Hybrids are mostly dwarf, early maturing, high yielding.

7. Agronomy (Cultural Practices)

• Season:
  • Kharif (June–July, with monsoon).
  • Rabi (Oct–Nov under irrigation in South India).
• Seed rate:
  • Varieties: 10–12 kg/ha.
  • Hybrids: 5–6 kg/ha.
• Spacing: 90–120 × 60 cm (varieties); 120 × 90 cm (hybrids).
• Sowing depth: 4–6 cm.
• Fertilizer requirement (general):
  • N: 80–120 kg/ha.
  • P₂O₅: 40–60 kg/ha.
  • K₂O: 40 kg/ha.
  • S: 20–25 kg/ha.
• Irrigation: Rainfed in Gujarat & Rajasthan; in irrigated areas → 5–6 irrigations.
  • Critical stages: flowering, capsule development, seed filling.

8. Weed Management

• Critical period: 20–50 DAS.
• Manual weeding: 2 times (20 & 40 DAS).
• Herbicides:
  • Pendimethalin @ 1.0 kg a.i./ha (PE).
  • Quizalofop-ethyl @ 50 g a.i./ha (for grassy weeds).

9. Pests & Diseases

• Pests:
  • Castor semilooper (Achaea janata).
  • Shoot & capsule borer (Conogethes punctiferalis).
  • Whitefly.
• Diseases:
  • Wilt (Fusarium oxysporum f.sp. ricini).
  • Leaf spot (Alternaria ricini).
  • Gray mold (Botrytis ricini).
• Management:
  • Resistant hybrids (GCH-7, DCH-177).
  • Seed treatment with Carbendazim/Trichoderma.
  • Need-based insecticide sprays (NSKE, Spinosad, Pyrethroids).

10. Quality Components

• Oil content: 45–50%.
• Unique fatty acid: Ricinoleic acid (~90%) → hydroxylated fatty acid.
• Non-edible oil (toxic due to ricin alkaloid).
• Excellent lubricant, resists high/low temperatures.

11. Industrial & Non-Food Uses

• Lubricants, hydraulic & brake fluids.
• Soaps, paints, varnishes, inks.
• Nylon, plastics, surfactants.
• Medicinal: Laxatives, pharma base.
• Oilcake: Rich in protein but toxic (after detoxification used as manure).

12. Economics

• High-value industrial crop.
• Export-oriented (India supplies >85% of global castor oil demand).
• B:C ratio ~2.0 under irrigated hybrids.

13. Post-harvest Technology

• Harvest when capsules turn brown & dry.
• Sequential harvesting (as capsules mature unevenly).
• Dry capsules → threshing → clean seeds.
• Seeds stored at 8–9% moisture.

14. Important MCQ Facts (Quick Recap)

• Botanical name: Ricinus communis L.
• Family: Euphorbiaceae.
• Origin: Africa (Ethiopia).
• Oil content: 45–50%.
• Protein: 18–20%.
• Unique acid: Ricinoleic acid (~90%).
• Seed rate: 10–12 kg/ha (varieties), 5–6 kg/ha (hybrids).
• Spacing: 90–120 × 60–90 cm.
• Critical irrigations: Flowering, capsule development, seed filling.
• Major pest: Castor semilooper.
• Major disease: Wilt.
• Special note: Castor oil is non-edible, industrial oil.