Turmeric
The Golden Wonder.
Preparation and Propagation
Climatic and Soil Requirements
Turmeric thrives in warm, humid tropical conditions with annual rainfall of 1,000–2,000 mm. Optimal temperature: 20–30°C.Best in well-drained, fertile loamy or alluvial soils rich in organic matter (pH 5.0–7.5). Avoid waterlogging for healthy rhizome development.
Variety Selection
High-curcumin and export-demand varieties suited for Kerala include: Alleppey Finger (5–7% curcumin) – globally known for its color and aroma Prabha, Suguna, and Suvarna — high-yielding commercial cultivars
Propagation
Use healthy, disease-free mother rhizomes (20–25 g each). Pre-treat rhizomes in 0.3% mancozeb or Trichoderma biofungicide for 30 minutes and air-dry before planting.
Land Preparation and Planting
Prepare raised beds or ridges to ensure drainage. Ideal planting time: May–June (pre-monsoon). Spacing: 45×30 cm, depth: 5–7 cm. Apply 10–12 tonnes/ha green leaf mulch immediately after planting.
Cultivation and Management
Manuring and Fertilization
Apply 20–25 tonnes/ha of compost or FYM during land prep. Recommended NPK per hectare: N 120 kg, P₂O₅ 50 kg, K₂O 100 kg (in 3 splits: Basal, 60 DAP, 120 DAP). Use Azospirillum and Phosphobacteria to enhance soil fertility.
Weeding and Earthing Up
Weed 2–3 times (30, 60, and 90 days after planting). Combine earthing up to cover exposed rhizomes and encourage healthy growth.
Water Management / Irrigation
Maintain consistent soil moisture after the monsoon. Irrigate every 7–10 days during dry months (December–March). Avoid overwatering to prevent Soft Rot. Drip irrigation ensures efficient use of water.
Pest and Disease Management
Common issues: Soft Rot, Leaf Spot, Shoot Borer, Rhizome Scale. Use Trichoderma, neem oil sprays, and pheromone traps under IPM practices. Comply with MRL (Maximum Residue Limit) standards.
Harvesting
Timing for Quality
Harvest 8–10 months after planting (January–March) when leaves turn yellow and dry — ensuring maximum curcumin.
Harvesting Technique
Manual digging (spades/forks) for small farms; mechanical diggers for large holdings.
Cleaning
Wash rhizomes after harvest to remove soil and roots.
Separate mother and finger rhizomes carefully.
Post-Harvest Processing
Curing / Boiling
Boil rhizomes in iron or copper vats for 45–60 minutes until soft. Avoid overboiling to preserve bright yellow color. Use potable water and clean equipment for export-grade turmeric.
Drying
Dry to 5–7% moisture using clean concrete yards or mechanical dryers at 60°C. Protect from rain and reabsorption of moisture.
Polishing
After drying, polish rhizomes in barrel/drum polishers to remove outer skin and enhance brightness.
Grinding
For powder exports: Use low-heat pulverisers to retain volatile oils and curcumin. Sieve through 80–100 mesh for uniform fineness.