Improved Red Spineless (IRS)
Listed as the red-fruited counterpart of the thornless green line; no source we could read describes a red spineless line, so treat any performance claim as unconfirmed.
Quick facts
- Type
- Research-centre line (existence unconfirmed)
- Season
- Kharif
- Maturity period
- Transplanted in June–July, harvested in November–December (north Bihar ponds)
- Expected yield
- No published figure found for a red spineless line
- Suitable soil
- Pond/diked-field silt (standing water)
- Disease resistance
- Not separately documented
- Release
- ICAR-RCER Research Centre for Makhana, Darbhanga (Bihar); status unconfirmed
Actual yield depends on sowing time, soil, irrigation, weather, seed quality and crop management.
About this variety
Improved Red Spineless (IRS) is described as the red-fruited counterpart of the thornless green line from the ICAR-RCER Research Centre for Makhana, Darbhanga. We could not confirm that such a line exists as described. The 2025 review by the Centre's B. R. Jana names Bihar Large Red (Spine) and a Green Spineless genotype but no red spineless one, and a 2018 Indian Farming article from the Centre mentions only 'newly identified thornless germplasm'. A 2024 Indian Journal of Horticulture study of 23 water chestnut lines (2020–21) may include it, but we could not open the paper. Until the Centre confirms, treat any claim for a red thornless line as unconfirmed, and use the local red-spined type, or the green thornless line, which has more published data, as your reference.
Should you pick this variety?
Choose this line only after the Research Centre for Makhana, Darbhanga confirms it exists and has stock. We could not find a published description, yield or release for a red spineless singhara. If you want red nuts, plant the local red-spined type, or ask the Centre for Bihar Large Red (Spine), which the 2025 review gives at 7.0 t/ha. If you want a thornless line, the green one has the published data (up to 12.0 t/ha).
Sowing & cultivation
Advantages & considerations
Why farmers may choose it
- If a red thornless line is available to you, thornless fruit should be easier and safer to pick and peel.
Things to consider
- No published description, yield or release status was found for a red spineless line. Ask the Research Centre for Makhana, Darbhanga before relying on it.
- The nearest published data are for Bihar Large Red (Spine), 7.0 t/ha, and a Green Spineless genotype, up to 12.0 t/ha (Jana, 2025).
Suitable regions
States this variety is recommended for — check locally, since a state can have more than one recommended zone.
- Bihar
What we could not confirm about a red thornless line
A red-fruited thornless line trialled by ICAR through 2021, with higher yield and sugar than local stock, is the claim usually attached to this name. We went looking for it and could not find it. The sources we could open name Bihar Large Red (Spine) and a Green Spineless genotype, mention 'thornless germplasm' without colour, and give no red spineless entry or 2021 trial. The entry stays so that a farmer who hears the name can see what is and is not published, in case the Centre confirms the line.
What would settle it is short: a letter or call to the Research Centre for Makhana, Darbhanga asking whether a red thornless singhara line exists, under what name, and with what trial data. Until then, a farmer who wants red nuts has a better-documented choice in the local red-spined type, and one who wants thornless fruit has the green line, which has a published yield range.
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)this page | 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 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
Does a red spineless singhara line exist?
We could not confirm it. The 2025 Agricultural Reviews article by B. R. Jana of the Research Centre for Makhana, Darbhanga names Bihar Large Red (Spine) and a Green Spineless genotype, not a red spineless one. A 2018 Indian Farming article from the Centre mentions 'newly identified thornless germplasm' without a name or colour. A 2024 Indian Journal of Horticulture study of 23 water chestnut lines may include it, but we could not open that paper.
What should I plant if I want red nuts?
The local red-spined type is the usual choice and costs nothing to start, giving 2.5 to 3.5 t/ha when well kept. The 2025 review reports 7.0 t/ha for Bihar Large Red (Spine), which it calls the commercial variety of the Mithila region around Darbhanga. We cannot say whether that is the same as the local red-spined type. Ask the Centre in Darbhanga for it by name, and compare it with your own stock in one pond before changing everything.
Which thornless singhara has published yield data?
The green one. The 2025 review says the maximum of 12.0 t/ha can be reached with a Green Spineless genotype, and that its study's yields ran from 4.2 to 12.0 t/ha. Those are research numbers under north Bihar wetland conditions, not farm averages. The thornless green line is covered separately.
Who can confirm what exists, and what should I ask?
The ICAR-RCER Research Centre for Makhana, Darbhanga is the place that wrote the 2025 review and the 2018 Indian Farming article. An ICAR-funded project on evaluating different genotypes of water chestnut ran from 2015 to 2020 at ICAR-RCER, Patna, with Dr Rajvir Sharma as principal investigator (ISTI portal). Ask the Centre: which thornless lines exist, what colour, what yield in your kind of pond, what stock is available, and whether the project report can be shared.
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), Evaluation of different genotypes of water chestnut — ICAR-RCER Patna project 2015 to 2020 (ISTI portal), Indian Journal of Horticulture, evaluation of 23 water chestnut lines, 2020–21 (seen as a search extract; the file did not open). editorial policy.