Local Green-spined biotype
A second farmer-saved singhara with a green, sharply spined nut, grown beside the red type in many ponds; the milder taste some farmers mention is local opinion, not measured.
Quick facts
- Type
- Farmer-saved seed nut / seedling (local biotype)
- Season
- Kharif
- Maturity period
- Transplanted in June–July, harvested in November–December (north Bihar ponds)
- Expected yield
- 25–35 q/ha for a well-kept local type; pond-dependent
- Suitable soil
- Pond/diked-field silt (standing water)
- Disease resistance
- Not formally documented
Actual yield depends on sowing time, soil, irrigation, weather, seed quality and crop management.
About this variety
The Local Green-spined biotype grows beside the red-spined type in singhara ponds of Bihar, eastern Uttar Pradesh and West Bengal, and in Jammu and Kashmir. Like the red type it is a farmer-saved population, not a released variety, and there is no certified seed. Some farmers call the green nut milder and less starchy; that is local opinion and we found no measured comparison. The only measured difference we found is crude fibre, 2.13% in a green variety against 2.27% in a red one (Faruk and others 2012, quoted in the 2025 review), a small gap. Do not confuse it with the green spineless line, a different, thornless type that has its own page.
Should you pick this variety?
Choose the local green-spined type if your buyers ask for green nuts or you want a second colour beside the red one in the same pond. It is a farmer-saved type with sharp spines and no certified seed, and its yield follows the pond and your care, like the red type. Do not confuse it with the green spineless line, which is thornless and has its own page. If you want the higher published yield, ask the Research Centre for Makhana, Darbhanga about the thornless green line.
Sowing & cultivation
Advantages & considerations
Why farmers may choose it
- Grown across the Bihar–Bengal belt and in Jammu and Kashmir, a record in two very different regions.
- A second colour to offer buyers beside the red type.
Things to consider
- No quality guarantee or institute seed source; sourcing depends on local farmers and ponds.
- The milder-taste idea is local opinion, not measured.
- Green-spined is not the same as Green Spineless: this type has sharp spines.
Suitable regions
States this variety is recommended for — check locally, since a state can have more than one recommended zone.
- Bihar
- Uttar Pradesh
- West Bengal
- Jammu and Kashmir
Calendar and water depth
Published singhara calendars are short. The 2025 review says that in the north Bihar water bodies it describes, transplanting is done in June to July and harvesting in November to December. A FAO case study of a 0.4 ha fish and singhara pond has seedlings transplanted in May or June into a perennial pond. Reports from West Bengal say the crop is harvested after the monsoon and into early winter. So the crop is planted as the rains start and picked from late autumn, and your own pond's water decides the exact weeks.
Water depth is the other fixed point. The review says traditional deep-water ponds hold 3 to 5 feet and that this makes field work difficult. West Bengal reports describe plots of 480 to 3,000 m² with water 75 to 180 cm deep over clay-rich silt. We found no depth figure for the green-spined type alone, and no fertiliser or nursery schedule in the sources we could open. Until the Darbhanga Centre or your KVK gives you one, copy what the best singhara pond near you does, and write down your own dates for next year.
Can you keep your own planting material?
This is an open-pollinated variety, so seed from a healthy crop of your own can be sown again. Keep seed only from disease-free plants, dry it properly, store it cool and dry, and bring in fresh certified seed every three to four years so the variety does not drift.
How it compares with other varieties
Every Water Chestnut (Singhara) variety with a page on this site, side by side. The row for this page is highlighted.
| Variety | Best for | Yield | States |
|---|---|---|---|
| Improved Green Spineless (IGS) | Pond farmers who want a thornless singhara and can get planting material from the Research Centre for Makhana, Darbhanga | Up to 12.0 t/ha reported for a Green Spineless genotype (research study, range 4.2–12.0 t/ha) | Bihar |
| Improved Red Spineless (IRS) | Farmers who heard of a red thornless singhara and want to know what is actually published before they plan around it | No published figure found for a red spineless line | Bihar |
| Local Green-spined biotypethis page | Farmers who want a second nut colour beside the red type in the same ponds and have buyers who ask for green singhara | 25–35 q/ha for a well-kept local type; pond-dependent | Bihar, Uttar Pradesh, West Bengal, Jammu and Kashmir |
| Local Red-spined biotype | Pond farmers in Bihar, eastern Uttar Pradesh and West Bengal who want the usual red-spined singhara and can save their own planting stock | 25–35 q/ha for a well-kept local type; pond-dependent | Bihar, Uttar Pradesh, West Bengal |
Tools for this crop
The numbers you need next: how much seed to buy, whether the lot germinates, what the fertilizer bill looks like and what Water Chestnut (Singhara) is selling for.
- Seed Rate CalculatorHow much seed your Water Chestnut (Singhara) plot needs, corrected for the germination of the lot you bought.
- Seed Variety FinderFilter every Water Chestnut (Singhara) variety on this site by state, season, duration and soil.
- Fertilizer CalculatorTurn the NPK recommendation for Water Chestnut (Singhara) into bags of urea, DAP and MOP for your field size.
- Crop Profit CalculatorPut your seed, labour and input costs against the yield you expect from this variety.
- Mandi Price CheckerToday's Water Chestnut (Singhara) rate in your nearest mandi, before you fix a price with a trader.
Subsidy and government support
Schemes that help with the cost of Water Chestnut (Singhara) seed or planting material. Rules and the application route are on each scheme page.
Frequently asked questions
Is green-spined the same as Green Spineless?
No. Green-spined is the ordinary farmer-saved green nut with sharp spines. Green Spineless is the thornless green genotype from the Research Centre for Makhana, Darbhanga, for which the 2025 Agricultural Reviews article reports a maximum of 12.0 t/ha. The two names differ by one syllable and the plants differ in thorns, yield data and where you can get planting material, so check the spelling before you order.
Does green singhara taste milder than red?
Some farmers say so, but we found no measured taste comparison. The only measured difference we found is crude fibre: 2.13% in a green variety against 2.27% in a red one (Faruk and others 2012, quoted in the 2025 review), a very small gap. Treat the milder-taste idea as local opinion. If buyers pay more for green nuts in your market, that is the real reason to grow them.
What water depth does singhara need?
The 2025 review says traditional deep-water ponds run 3 to 5 feet deep, and that this makes work in the pond hard. Reports from West Bengal describe shallow ponds with water 75 to 180 cm deep and plots of 480 to 3,000 m². We found no depth figure for the green-spined type alone. Level your plot so water depth is even, and look at what the best singhara ponds near you hold at transplanting.
Where is singhara sold, and in what form?
The 2025 review names Kolkata, Bombay, New Delhi, Patna, Bhopal, Chennai and Hyderabad as markets. Fresh nuts are sold in season, and the dried kernel is ground into flour (singhara atta), which is gluten free and widely eaten during Navratri. The review gives India's output as 67,600 t from 16,900 ha in one place and 76,050 t in another, so the national figure is uncertain. For a price, ask local traders; we found no MSP or mandi price series.
Is singhara planted from tubers?
No. Singhara is a water plant that grows from its seed nut, which sprouts into floating vines; it has no tuber. The 2025 review says farmers transplant in June to July, and a FAO case study describes seedlings transplanted in May or June. We found no published seed-nut rate or nursery schedule, so ask your KVK or the Research Centre for Makhana, Darbhanga how much planting stock a hectare needs.
Sourced from: Jana, Recent Production and Marketing Scenarios of Water Chestnut (Trapa spp.) in India: A Review — Agricultural Reviews 46(2), 2025 (ICAR-RCER Research Centre for Makhana, Darbhanga), Trends in water chestnut Trapa bispinosa farming in West Bengal, India — NACA (pond depth and plot size; seen as a search extract), FAO, Fish and Trapa culture case study (seedlings transplanted May to June). editorial policy.