IISR Viswashree
Released in 2001 by ICAR-Indian Institute of Spices Research (IISR), Kozhikode. Clonal selection from an elite tree (accession A-9/4) from Mannoor, Kozhikode district. Bushy, compact growth habit. Female variety — needs a male tree nearby for pollination.
Quick facts
- Crop
- Nutmeg (Jaiphal)
- Type
- Grafted plant (improved variety)
- Season
- All seasons
- Maturity period
- First harvest about year 6; full bearing by year 15–25
- Seed rate
- About 50–60 grafted plants per acre at 8 × 8 m spacing; keep one male tree for every 10–12 female grafts
- Expected yield
- About 3,122 kg dry nuts + 480 kg mace/ha at year 8 (360 grafts/ha)
- Suitable soil
- Deep, well-drained clay loam, laterite or forest soil
- Release
- ICAR-IISR, Kozhikode, 2001 — clonal selection from accession A-9/4, Mannoor, Kerala
About this variety
IISR Viswashree was the first nutmeg variety released in India (2001), developed by ICAR-Indian Institute of Spices Research, Kozhikode, through clonal selection from an elite mother tree (accession A-9/4) collected from Mannoor, Kozhikode district, Kerala. It has a bushy, compact growth habit that suits homestead and mixed gardens. At 8 years of age with 360 grafts per hectare, it produced about 1,000 fruits per tree, yielding about 3,122 kg dry nuts and 480 kg dry mace per hectare. The dry nut recovery is about 70% and mace recovery about 35%. Oil content runs about 7.14% in the nut and 7.13% in the mace. Low incidence of Diplodia fruit rot has been reported. Being a female variety, it needs at least one male tree within about 50–100 m for wind-borne pollination.
Key characteristics
Sowing & cultivation
- Sowing timeRainy season (June–December); shade plants established 6–12 months earlier
- Seed rateAbout 50–60 grafted plants per acre at 8 × 8 m spacing; keep one male tree for every 10–12 female grafts
- SpacingAbout 8 × 8 m
- Sowing methodOne grafted plant per prepared pit (60 × 60 × 60 cm), filled with topsoil and cattle manure, then shaded and watered in
- IrrigationEvery 5–7 days in summer; drip or basin irrigation
- FertilizerYoung tree: 20:20:60 g N:P₂O₅:K₂O + 15 kg FYM/year; bearing tree: about 300:300:960 g + 50 kg FYM (TNAU schedule)
- HarvestingFruits picked when outer husk splits, exposing the red mace; mace peeled off and dried separately, nut dried in shell then shelled and graded
Soil & climate
Soil
- Suitable soil
- Deep, well-drained clay loam, laterite or forest soil rich in organic matter
- Irrigation
- Free drainage essential; waterlogging harmful
Climate
- Maturity
- About 20–30°C mean
- Irrigation
- About 1,500–2,500 mm a year, well distributed
- Climate
- Warm, humid tropical; partial shade for young plants, sheltered sites up to about 1,000 m elevation.
Yield & maturity
Maturity period
First harvest about year 6; full bearing by year 15–25
Expected yield
About 3,122 kg dry nuts + 480 kg mace/ha at year 8 (360 grafts/ha)
Actual yield depends on sowing time, soil, irrigation, weather, seed quality and crop management.
Pest & disease considerations
Major pests
- Loranthus (parasitic plant)
Management notes
- Choose a sheltered, well-drained site with assured water for the dry months.
- Establish shade (banana or fast-growing trees) 6–12 months before planting.
- Keep one confirmed male tree for every 10–12 female grafts for pollination.
- Prune overlapping branches to improve air circulation and reduce fruit rot.
- Remove and destroy fallen rotten fruit promptly to break the disease cycle.
Advantages & considerations
Why farmers may choose it
- First released nutmeg variety in India — well-documented performance data
- Bushy, compact growth suits homestead and mixed gardens
- Low Diplodia fruit rot incidence reported
- High dry nut recovery (70%) and mace recovery (35%)
Things to consider
- Female variety — must keep male trees for pollination
- First useful crop only from about year 6; full bearing takes 15+ years
- Available mainly through IISR Kozhikode and KAU nurseries — check ahead for graft availability
- Needs shade, regular watering and good drainage — not suitable for dry or waterlogged sites
Suitable regions
Released for Kerala's nutmeg-growing districts (Idukki, Ernakulam, Thrissur, Kottayam). Suitable for all traditional nutmeg areas with warm, humid climate.
- Kerala
Frequently asked questions
Where can I get IISR Viswashree grafts?
From the ICAR-Indian Institute of Spices Research (IISR), Kozhikode, Kerala, or from Kerala Agricultural University (KAU) nurseries. Contact them before the planting season to confirm availability, as demand for grafted nutmeg plants often exceeds supply.
How is Viswashree different from Keralashree?
Viswashree (2001) has a bushier, more compact habit and reported yield of about 3,122 kg dry nuts/ha by year 8. Keralashree (2013) is a later release with bolder nut, thicker mace and higher reported yield of about 7,560 kg nuts/ha by year 10. Both are female varieties from IISR. Keralashree is the higher-yielding newer release; Viswashree is the older, more field-tested one.
Sourced from: ICAR-IISR Kozhikode — Nutmeg varieties, TNAU Agritech Portal — Nutmeg, Spices Board India — Nutmeg. editorial policy.