Taro (Colocasia) Farming — Organic Wetland Crop

Taro (colocasia, arbi) is one of the most dependable organic root crops for Karnataka farmers — tolerating both waterlogged conditions near irrigation tanks and well-drained upland plots, depending on variety. Both the corms (roots) and the large leaves are marketable commodities, providing income from two distinct products in a single crop. Income of ₹50,000–90,000/acre in 5–6 months makes taro particularly attractive where rice or other wetland crops are not viable.

Variety Selection — Wetland vs. Upland Types

Muktakeshi: A traditional upland variety suited to Karnataka’s red and laterite soils. Produces medium-sized corms with white flesh and low acridity — suitable for direct cooking without prolonged boiling. Leaves are smaller than wetland types; plant habit compact; matures in 5 months.

Satamukhi: A prolific variety producing clusters of many small daughter cormels around the main corm — the name means “hundred-headed”. Preferred by farmers selling to vegetable markets where small arbi are in high demand. Matures in 5–6 months; suited to moisture-retentive soils with good organic matter.

Kerala Local (Chembu): The dominant wetland variety of Kerala and coastal Karnataka. Large corms, very high yield potential (12–15 tonnes/acre in flooded paddy-style cultivation). Low acridity — can be eaten as a boiled vegetable without extensive preparation. Best suited to canal irrigated or near-water table plots.

Pankaj and Black Magic (table varieties): Newer varieties with purple-fleshed corms — extremely high demand in urban supermarkets and organic specialty stores for their visual appeal and higher polyphenol content. Premium of 50–80% over white-flesh types justifies lower yield.

Planting from Cormels

Taro is propagated vegetatively from small daughter cormels or cormel tops — not from seeds. This ensures variety fidelity and allows farmers to maintain local adapted varieties indefinitely.

Planting material selection:

1. Select healthy, firm cormels of 50–100g weight from previous season’s harvest
2. Cormels should be free of rot, weevil damage, or discolouration
3. Treat planting material with Trichoderma viride solution (5g/L) for 30 minutes to suppress storage rot fungi
4. Sun dry for 2–3 days after treatment; do not plant wet cormels

Spacing:

• Upland cultivation: 60×45 cm or 75×45 cm; plant cormels 8–10 cm deep
• Wetland cultivation: 75×60 cm; plant after primary land preparation in standing water

Soil Preparation and Nutrition

Taro is a heavy feeder due to its large leaf area and starchy corm development. Organic matter is the most important input.

Per acre soil preparation:

• Vermicompost: 4 tonnes (high rate for this crop)
• Neem cake: 200 kg (pest suppression in root zone)
• Wood ash: 200 kg (potassium for corm development)
• Incorporate all into top 20 cm before planting

Top dressing at 60 days: Apply 2 tonnes compost between rows and earth up around plants — this encourages additional cormel formation in the soil and keeps roots covered.

Waterlogged vs. Upland Cultivation

Leaf Blight Management

Taro leaf blight (Phytophthora colocasiae) is the most serious disease — water-soaked lesions appear on large leaves, rapidly expanding to cover the entire leaf and causing collapse. Warm, humid Kharif conditions with rain splash spread the pathogen rapidly.

Organic management:

• Copper-based fungicide: Bordeaux mixture 1% sprayed at 14-day intervals from day 60 onwards when conditions are humid
• Plant spacing: Adequate spacing (60–75 cm) ensures air circulation between large leaves — critical for reducing blight
• Avoid overhead irrigation: Switch to drip or furrow irrigation after day 45 — wet foliage is the primary blight trigger
• Remove infected leaves: Harvest and compost affected leaves immediately on detection; do not leave on the field
• Resistant varieties: Some local varieties show moderate blight tolerance — prefer these in high-blight-pressure environments

Harvesting Corms and Leaves

Leaf harvest (income while waiting for corms): Taro leaves are a popular vegetable in Karnataka (known as kesuvina soppu) — used in sambar, curry, and the traditional pathrode (colocasia leaf rolls). Harvest 2–3 large outer leaves per plant monthly from day 45 onwards without damaging the plant’s growth. At ₹20–40/kg, leaf harvesting provides significant income during the 5–6 month crop period.

Corm harvest: At 5–6 months, leaves begin to yellow and die back — this is the harvest signal. Dig carefully with a fork, separate daughter cormels from the main corm, and grade by size. Large corms for wholesale; small cormels (with good firm skin) can be retained as planting material for the next season.

Income breakdown:

• Corm yield: 10 tonnes/acre × ₹10/kg = ₹1,00,000 gross
• Leaf harvest (monthly): ₹10,000–20,000 over crop period
• Input + labour: ₹35,000–45,000
• Net income: ₹55,000–90,000/acre

Last updated: March 2026