H-97
A 1971 CTCRI hybrid, one of the three oldest on the list, with 27-31% starch and drought tolerance. It is the high-cyanogen end of the CTCRI table, 180-200 ppm. 25-35 t/ha in 10 months, for Kerala, Tamil Nadu, Karnataka and Andhra Pradesh.
Quick facts
- Type
- Stem cutting (clonal planting material)
- Season
- Kharif
- Maturity period
- 10 months (CTCRI bulletin and Indian Horticulture 2025)
- Expected yield
- 25-35 t/ha (CTCRI bulletin, web page and Indian Horticulture 2025)
- Suitable soil
- Loam
- Release
- Released 1971 · ICAR-CTCRI, Thiruvananthapuram, a hybrid (CTCRI bulletin, Table 3)
About this variety
H-97 is a hybrid cassava variety released in 1971 by ICAR-CTCRI. CTCRI's bulletin describes an erect, branching plant with a dark grey mature stem, a light sepia emerging leaf and a dark green petiole, and cylindrical tubers with light brown skin, cream rind and white flesh. It takes 10 months, gives 25-35 t/ha with 27-31% starch, is drought tolerant, and moderately resistant to Cercospora leaf spot, spider mite and scale insect. It is recommended for Kerala, Tamil Nadu, Karnataka and Andhra Pradesh. Indian Horticulture (2025) lists its cyanogen at 180-200 ppm and calls the cooking quality good. The older web page describes medium-tall plants of 1.5-2 m and adds tolerance to cassava mosaic disease, which the bulletin table does not list.
Should you pick this variety?
Choose H-97 if you grow cassava for a factory on dry land in Kerala, Tamil Nadu, Karnataka or Andhra Pradesh and want a drought-tolerant, long-tested hybrid. CTCRI released it in 1971: 10 months, 25-35 t/ha, 27-31% starch, erect and branching, moderately resistant to Cercospora leaf spot, spider mite and scale insect. Its yield range, 25-35 t/ha, is among the lowest on the CTCRI list, and its cyanogen at 180-200 ppm is the highest figure on the table, so it is an industrial variety first and should be cooked carefully. For fresh eating, look at Sree Reksha (35.01 ppm).
Key characteristics
Sowing & cultivation
- Sowing timeMay-June with the south-west monsoon, or September-October with the north-east monsoon; December-January if irrigated (CTCRI).
- SpacingBranching types: 90 x 90 cm in Kerala and Andhra Pradesh, 90 x 75 cm in Tamil Nadu, Maharashtra, Gujarat and Chhattisgarh (CTCRI Table 7). About 2,500 stems a hectare at 90 x 90 cm.
- Sowing methodCut setts of 15-20 cm with about five nodes from mature, healthy stems 2-3 cm thick, discard the top third, and plant them vertically 5 cm deep, one sett to a mound (CTCRI). Good planting stakes show latex at the cut end.
- FertilizerCTCRI: 12.5 t/ha FYM and 100:50:100 kg N:P2O5:K2O. Put all the phosphorus and half the nitrogen and potash on at planting, and the rest at 45-60 days with weeding.
- HarvestingHarvest at the listed duration, 10 months.
Soil & climate
Soil
- Suitable soil
- Well-drained loam; saline, alkaline and ill-drained soils are not suitable, and cassava cannot thrive on waterlogged soil (CTCRI)
Yield & maturity
Maturity period
10 months (CTCRI bulletin and Indian Horticulture 2025)
Expected yield
25-35 t/ha (CTCRI bulletin, web page and Indian Horticulture 2025)
Actual yield depends on sowing time, soil, irrigation, weather, seed quality and crop management.
Pest & disease considerations
Major diseases
- Cassava mosaic disease (CMD), spread by whitefly and by infected cuttings
- Cercospora leaf spot
- Tuber rot in waterlogged soil
Major pests
Management notes
- Use clean stakes only: CTCRI allows 0.10% mosaic-affected plants in foundation seed and 0.50% in certified seed, so take stakes from a crop with no mosaic and pull out any diseased plant early.
- Keep two sprouts on each plant: nip off the extra sprouts 10-15 days after sprouting and keep two on opposite sides, which means more tubers per plant (CTCRI).
Advantages & considerations
Why farmers may choose it
- Drought tolerant, with 27-31% starch.
- Moderately resistant to Cercospora leaf spot, spider mite and scale insect.
- More than fifty years of use in southern farms.
Things to consider
- A low yield range, 25-35 t/ha, among the lowest on the CTCRI list.
- The highest cyanogen figure on the table, 180-200 ppm.
- The web page and the bulletin differ on mosaic tolerance.
Suitable regions
States this variety is recommended for — check locally, since a state can have more than one recommended zone.
- Kerala
- Tamil Nadu
- Karnataka
- Andhra Pradesh
The cyanogen ladder: H-97 against the newer varieties
Indian Horticulture (2025) gives cyanogen values for four CTCRI cassavas. Sree Reksha (2017) 35.01 ppm. Sree Harsha (1996) 40-55 ppm. Sree Sahya (1977) 75-85 ppm. H-97 (1971) 180-200 ppm. The article labels all of them as low-cyanogen with good cooking quality, which is relative to wild bitter cassava, not an assurance that H-97 is safe raw.
The ladder tells you which to eat and which to sell. H-97 carries about five times the cyanogen of Sree Reksha. For the table, choose the lower rungs, peel and cook thoroughly, and for factory use H-97 is fine because processing removes cyanogen. If you grow H-97 for both, label the fresh lot clearly and do not sell it for raw use. CTCRI's bulletin notes that wood ash and zinc given on a soil test lower tuber cyanogen, so feed the crop accordingly if you plan to sell any of it fresh.
Can you save seed from this crop?
Cassava is planted from stem cuttings, not seed. Take stakes from a healthy crop of 6-7 months for a short-duration variety or 9-10 months for a long one, keep them upright in shade, and avoid damaging the nodes in transport. The same variety gets weaker if you keep re-using stakes from poor plants, so refresh your planting material from a clean source now and then.
How it compares with other varieties
Every Tapioca (Cassava) variety with a page on this site, side by side. The row for this page is highlighted.
| Variety | Best for | Starts bearing | Yield | States |
|---|---|---|---|---|
| H-165 | Tamil Nadu, 8-month industrial | 8 months (CTCRI); 8-9 months (ISTI portal) | 33-38 t/ha | Tamil Nadu, Kerala, Andhra Pradesh, Karnataka |
| H-226 | Starch and sago, Tamil Nadu | 10 months (CTCRI and ISTI portal) | 30-35 t/ha | Tamil Nadu, Kerala, Andhra Pradesh, Karnataka |
| H-97this page | Dry-land farms in four southern states that want a drought-tolerant, high-starch, long-tested variety for factory sale | 10 months (CTCRI bulletin and Indian Horticulture 2025) | 25-35 t/ha (CTCRI bulletin, web page and Indian Horticulture 2025) | Kerala, Tamil Nadu, Karnataka, Andhra Pradesh |
| Sree Apoorva | Starch-factory farms in Tamil Nadu and Andhra Pradesh that want a stable, high extractable starch triploid | 10 months (CTCRI bulletin) | 35-40 t/ha (CTCRI bulletin); 37.60 t/ha (CTCRI web page) | Tamil Nadu, Andhra Pradesh, Kerala |
| Sree Athulya | High-starch triploid, irrigated plains | 10 months (CTCRI bulletin) | 35-40 t/ha (CTCRI); 39.00 t/ha (ISTI portal) | Tamil Nadu, Kerala, Andhra Pradesh |
| Sree Harsha | Starch-factory farms in Kerala and Tamil Nadu that are paid by the percentage of starch | 10 months (CTCRI bulletin and Indian Horticulture 2025) | 35-40 t/ha (CTCRI bulletin and Indian Horticulture 2025) | Kerala, Tamil Nadu |
| Sree Jaya | Best-cooking six-month crop | 6-7 months | 26-30 t/ha | Kerala, Tamil Nadu |
| Sree Kaveri | Industrial cassava farmers in Tamil Nadu, Andhra Pradesh and Kerala who want mosaic resistance and a high yield | 9-10 months (CTCRI bulletin); 10 months (Indian Horticulture 2025) | 40-50 t/ha (CTCRI bulletin); 50 t/ha (Indian Horticulture 2025) | Tamil Nadu, Andhra Pradesh, Kerala |
| Sree Padmanabha | Rainfed Kerala and irrigated Tamil Nadu farms in mosaic-prone areas that want a proven, older resistant variety | 9-10 months (CTCRI bulletin); 270-300 days (CTCRI web page) | 29-30 t/ha (CTCRI bulletin); 38 t/ha (CTCRI web page) | Kerala, Tamil Nadu |
| Sree Pavithra | Low-potash soils, cooking | 9-10 months | 35-40 t/ha (CTCRI); 35-45 t/ha in a review table | Kerala, Tamil Nadu |
| Sree Prabha | Mixed-use farms in four states that want a medium-height variety for both lowland and upland | 9-10 months (CTCRI bulletin) | 35-40 t/ha (CTCRI bulletin) | Kerala, Tamil Nadu, Karnataka, Andhra Pradesh |
| Sree Prakash | Kerala lowland and paddy-rotation farms that want a quick, 7-month cassava | 7 months (CTCRI bulletin and web page) | 30-35 t/ha (CTCRI bulletin and web page) | Kerala |
| Sree Rekha | Mixed upland and lowland | 8-10 months (CTCRI variety page); 9-10 in the bulletin | 35-40 t/ha (CTCRI bulletin); 45-48 t/ha (CTCRI variety page, review table and ISTI portal) | Kerala, Tamil Nadu, Andhra Pradesh, Karnataka |
| Sree Reksha | Kerala and Tamil Nadu farms that sell cassava to eat and want mosaic resistance and a longer shelf life after harvest | 8-9 months (CTCRI bulletin and Indian Horticulture 2025) | 40-45 t/ha (CTCRI bulletin); 45-50 t/ha (Indian Horticulture 2025) | Kerala, Tamil Nadu |
| Sree Sahya | Farms in dry or mixed conditions across many states that want high starch and a dependable, old variety | 10-11 months (CTCRI bulletin, web page and Indian Horticulture 2025) | 35-40 t/ha (CTCRI bulletin, web page and Indian Horticulture 2025) | Kerala, Tamil Nadu, Karnataka, Maharashtra, Assam, Andhra Pradesh |
| Sree Sakthi | Industrial cassava farms in Tamil Nadu, Andhra Pradesh, Maharashtra and Kerala where mosaic disease is severe | 9-10 months (CTCRI bulletin) | 40-45 t/ha (CTCRI bulletin) | Tamil Nadu, Andhra Pradesh, Maharashtra, Kerala |
| Sree Suvarna | Farms that want a short, mosaic-proof cassava with low cyanogen for fresh use | 7-8 months (CTCRI bulletin) | 35-40 t/ha (CTCRI bulletin) | Kerala, Tamil Nadu, Andhra Pradesh |
| Sree Swarna | Kerala farms that sell cassava to eat and want a yellow-fleshed, early-bulking type | 7-8 months (CTCRI bulletin); early bulking at 7 months (CTCRI web page) | 35-40 t/ha (CTCRI bulletin); 40 t/ha (CTCRI web page) | Kerala |
| Sree Vijaya | Six-month crop after rice | 6 months (CTCRI variety page); 6-7 or 7 months in other CTCRI documents | 25-28 t/ha | Kerala, Tamil Nadu |
| Sree Visakham | Farms in many states, including Assam and the north-east, that want an old, widely grown, yellow-fleshed cassava | 10 months (CTCRI bulletin and web page) | 35-38 t/ha (CTCRI bulletin); 35-38 t/ha (CTCRI web page) | Kerala, Tamil Nadu, Karnataka, Maharashtra, Assam, Andhra Pradesh |
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 Tapioca (Cassava) is selling for.
- Seed Rate CalculatorHow much seed your Tapioca (Cassava) plot needs, corrected for the germination of the lot you bought.
- Seed Variety FinderFilter every Tapioca (Cassava) variety on this site by state, season, duration and soil.
- Fertilizer CalculatorTurn the NPK recommendation for Tapioca (Cassava) 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 Tapioca (Cassava) rate in your nearest mandi, before you fix a price with a trader.
Subsidy and government support
Schemes that help with the cost of Tapioca (Cassava) seed or planting material. Rules and the application route are on each scheme page.
Frequently asked questions
What is H-97?
A hybrid cassava variety released in 1971 by ICAR-CTCRI. It takes 10 months, gives 25-35 t/ha with 27-31% starch and is drought tolerant.
Is H-97 safe to eat?
Cooked well, as with any cassava, yes. But its cyanogen, 180-200 ppm, is the highest on CTCRI's table, so peel, cook it thoroughly and do not eat it raw. For fresh sale, Sree Reksha at 35.01 ppm is the safer choice.
Does H-97 resist cassava mosaic disease?
CTCRI's older web page says tolerant. The bulletin table and Indian Horticulture list only drought tolerance and moderate resistance to leaf spot, spider mite and scale insect. Do not count on mosaic resistance; use clean stakes.
H-97, H-165 or H-226?
All three were released in 1971. H-97: 10 months, 25-35 t/ha, 27-31% starch, drought tolerant. H-165: 8 months, 33-38 t/ha, 24% starch. H-226: 10 months, 30-35 t/ha, 28-30% starch, the most popular industrial variety in Tamil Nadu. H-97 has the lowest-looking yield range but is the drought pick.
Sourced from: Cassava (variety descriptions, Table 3; spacing, Table 7; planting stakes and seed standards) — ICAR-CTCRI, Cassava varieties developed by CTCRI — ICAR-CTCRI variety page, archived, Climate-resilient and biofortified tuber crop varieties — Chandra and others, Indian Horticulture, November-December 2025. editorial policy.