Singhara (water chestnut, Trapa) is a rainy-season crop for ponds and shallow wetlands of 0.3 to 0.6 m water depth, grown mainly in Bihar, Madhya Pradesh, Uttar Pradesh, West Bengal and Odisha, planted around July and harvested from October to December. It suits people who already have or can lease a pond; it is not a crop for dry land, and the real constraints are water-body rights, labour for harvest and a short selling window.

Indian yield records put fresh fruit at roughly 4 to 4.5 t per hectare (1.6 to 1.8 t per acre) on average, with a wide reported potential of 1 to 6 t per hectare. No reliable published cost of cultivation or farm-gate price was found, so returns below are shown as a formula to apply to your local price.

Where it grows in India

  • States: Bihar, Madhya Pradesh, West Bengal, Odisha, Assam, Uttar Pradesh, Maharashtra, Punjab and Tamil Nadu (ICAR-RCER review by B.R. Jana). The review puts the area at about 16,900 ha and production at 67,600 t.
  • Water: still or slow fresh water, with a water pH of about 6.7 to 8.2 reported. ICAR-RCER notes it needs 0.30 to 0.60 m of water throughout growth, though traditional ponds are deeper at 3 to 5 feet (about 0.9 to 1.5 m), which lowers yield.
  • Season: it is grown from July to November. In ICAR-RCER's Darbhanga pond trials, water chestnut was planted in the second week of August and first harvested in the last week of October.
  • Species: Trapa natans and Trapa bispinosa are both reported from India.

Varieties

TypeSourceTraitsNotes
Green SpinelessGenotype named in the ICAR-RCER reviewReported up to 12 t per hectare, against 7 t for Bihar Large RedNot a formally released variety; ask the research centre for planting material
Bihar Large RedNamed local line7 t per hectare in the reviewUsed as the comparison line in the review
  • A 2024 ICAR-IIVR study of 23 accessions found that fresh nut yield rises with leaf number and nut weight, and that breeding for these is possible. India has many local accessions but few named, released varieties.
  • Use fruit or vines from a healthy local crop with large, well-filled nuts, and ask your KVK or the nearest ICAR centre where improved lines are available.

Planting and spacing

  • ICAR-RCER's integrated trials planted water chestnut at about 7,000 plants per hectare (about 2,800 per acre).
  • Keep the water within 0.3 to 0.6 m through the season; no detailed Indian planting schedule beyond the dates above was found, so follow your KVK.
  • Decide first who holds the right to the pond. If the pond is not your own, get the lease or permission in writing from the owner (often the panchayat or a government department) before investing.

Nutrition and pests

  • No Indian fertiliser schedule for singhara was found. Ask your KVK, and avoid heavy chemical use in water that also holds fish.
  • The singhara beetle (Galerucella birmanica) is the main insect pest reported in Indian studies, and seedling root-dip treatments are used against it. Ask your KVK for the current recommendation and follow the label, since the crop grows in water and is eaten.

Harvest and yield

  • Harvest runs from late October (first picking in ICAR-RCER's Darbhanga trials) to December in traditional ponds. Ask local growers for the picking interval and the stage buyers want.
  • Average: 4 to 4.5 t fresh fruit per hectare and 1 to 1.5 t dry nut per hectare (Jana review), which is about 1.6 to 1.8 t fresh and 0.4 to 0.6 t dry per acre.
  • Range: ICAR-RCER gives a yield potential of 1 to 6 t per hectare (400 to 2,400 kg per acre). Deep traditional ponds are generally lower yielding.
💡 Tip: Keep water in the shallow 0.3 to 0.6 m band that ICAR-RCER recommends, and agree your selling channel before the first pick, because fresh nuts are perishable.

Cost and returns

  • Price: no verified farm-gate price was found. Fresh singhara prices vary by season and city; check local traders and mandi bhav in the first weeks of the season.
  • Formula (per acre): at 1.6 to 1.8 t fresh fruit, each ₹10 per kg is worth ₹16,000 to ₹18,000; each ₹20 per kg is worth ₹32,000 to ₹36,000. At the low yield of 400 kg per acre the same ₹10 gives only ₹4,000.
  • Costs: planting material, labour for planting and repeated picking, boat hire, pond lease and transport. No published Indian cost of cultivation was found; record your own for one season.
  • ICAR-RCER's Darbhanga trials combined makhana, fish and water chestnut in ponds; the combinations out-earned makhana alone, but those results are for the integrated system, not water chestnut alone.

Market and risks

  • Most singhara is sold fresh, boiled or raw, in local markets in October to December, and it is also dried and ground into singhara flour used in fasting foods.
  • Prices can fall when many ponds harvest together. Selling to a nearby city market or processor, or processing to dry nut and flour, spreads the risk. See FPO for group marketing.
  • Picking and planting mean long hours in water and are labour intensive; plan labour in advance.
  • For fisheries, pond and horticulture support, check the subsidy finder and your state fisheries department. No singhara-specific subsidy rate was verified.

Sources