Local Red-spined biotype
The common red-spined singhara of Bihar, eastern Uttar Pradesh and West Bengal ponds, kept by farmers from season to season; yield depends on the pond and on how carefully planting stock is picked.
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; standard field hygiene applies
Actual yield depends on sowing time, soil, irrigation, weather, seed quality and crop management.
About this variety
The Local Red-spined biotype is the planting stock most singhara farmers in Bihar's Mithila and Kosi districts, eastern Uttar Pradesh and West Bengal use. It is not a released variety. It is a farmer-saved population with a reddish nut carrying two sharp spines. Farmers keep stock from one season to the next from their own pond, and there is no certified seed channel. The Research Centre for Makhana, Darbhanga reports that a well-kept local type gives 2.5 to 3.5 t/ha, and puts the average of traditional farming at 3.5 to 4.0 t/ha (Jana, Agricultural Reviews, 2025). The same review names Bihar Large Red (Spine) as the commercial variety of the Mithila region, at 7.0 t/ha. We cannot say whether that is the same as this local biotype. Yield and nut quality still differ a lot from pond to pond.
Should you pick this variety?
Choose the local red-spined type if you already have a pond, want the cheapest start, and sell to buyers used to the red nut. Expect 2.5 to 3.5 t/ha from a well-kept local type, with 3.5 to 4.0 t/ha as the traditional average in the 2025 Darbhanga review. Research reports 7.0 t/ha for Bihar Large Red (Spine) and up to 12.0 t/ha for a Green Spineless genotype, so if you can get that stock from the Research Centre for Makhana, Darbhanga, ask for it. Pick planting stock from your best plants each year.
Sowing & cultivation
Advantages & considerations
Why farmers may choose it
- Freely available inside the growing belt, with no nursery or institute to approach.
- Suited to local pond conditions after years of selection by farmers.
Things to consider
- No quality guarantee: yield and nut quality depend on the pond's own planting-stock history.
- Research reports well above the local figure (7.0 t/ha for Bihar Large Red (Spine), up to 12.0 t/ha for a Green Spineless genotype), so a local biotype leaves yield on the table if better stock becomes available to you.
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
Why 7 tonnes and 3 tonnes can both be true
Singhara yield figures in print look contradictory because they describe different things. The 2025 review by B. R. Jana of the Research Centre for Makhana, Darbhanga gives four numbers. A well-kept local genotype gives 2.5 to 3.5 t/ha (Jana 2016), and traditional deep-water farming averages 3.5 to 4.0 t/ha. Bihar Large Red (Spine), the commercial variety of the Mithila region, gives 7.0 t/ha (Jana and others 2019). A Green Spineless genotype gives up to 12.0 t/ha. The study's own trials ran from 4.2 to 12.0 t/ha. The first two describe pond farming as it is. The last two describe research stock and research care.
For your pond, the useful comparison is not the highest number but the one next to yours. Plant a small plot of better stock in the same pond as your usual red-spined crop, record both harvests, and decide from that. In the meantime, the 25 to 35 q/ha given above is the figure for a well-kept local red-spined type, and anything above it should be treated as a target, not a promise. The review also gives India's output as 67,600 t from 16,900 ha in one place and 76,050 t in another, a reminder that even national figures are rough.
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 biotype | 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 biotypethis page | 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
Why is my pond's yield far below the 7 t/ha in research reports?
The 7.0 t/ha figure is for Bihar Large Red (Spine) in the 2025 Agricultural Reviews article by B. R. Jana of the Research Centre for Makhana, Darbhanga, quoting Jana and others 2019. The same article says a well-kept local type gives 2.5 to 3.5 t/ha and the traditional average is 3.5 to 4.0 t/ha. The part we could read does not say what the research ponds did differently. Water depth, planting stock and care are the usual differences, so compare your pond with a good neighbour's before changing anything.
When do I plant and when do I harvest red-spined singhara?
In the north Bihar ponds the 2025 review describes, transplanting is done in June to July and harvesting in November to December. In West Bengal, reports describe harvest after the monsoon and into early winter. A FAO case study of a fish and singhara pond says seedlings were transplanted in May or June. So the window is about the start of the rains, and your pond's water level sets the exact week. Local KVK advice for your district should override these general dates.
Is red singhara more nutritious than green?
We found no measured difference that matters to a buyer. The 2025 review gives crude fibre of 2.27% in a red variety against 2.13% in a green one (Faruk and others 2012), and says fresh nuts are about 80% water with TSS of 7.0 to 9.0 °Brix. The review's protein figures conflict (1.87% in one place, 4.40% in another), so we do not quote one. Sell on freshness and size, not on colour claims.
Would a thornless line pay better than red-spined?
On reported yields it could: up to 12.0 t/ha for a Green Spineless genotype against 7.0 t/ha for Bihar Large Red (Spine) in the 2025 review, whose study range was 4.2 to 12.0 t/ha. But that is research, not a farm average, and we found no public source of planting material. A 2018 Indian Farming article from the same Centre describes 'newly identified thornless germplasm' without a name. Ask the Centre in Darbhanga before you plan around it.
Can I grow singhara together with makhana or fish?
Research says yes. A 2018 Indian Farming article by Singh, Thakur and Prakash reports that the highest benefit to cost ratio, 1.79, came from a foxnut and water chestnut combination, and describes a foxnut and fish model in a field system. A FAO case study describes singhara with fish in a perennial pond, with seedlings transplanted in May or June. Fish and singhara need the pond managed for both, so start small and ask your fisheries officer about stocking and spraying.
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), Singh, Thakur and Prakash, Scientific cultivation of water chestnut crop a boon for poor fishermen — Indian Farming 68(3), 2018 (abstract only), FAO, Fish and Trapa culture case study (seedlings transplanted May to June). editorial policy.