IISR Keralashree
Released in 2013 by ICAR-IISR — the first nutmeg variety developed through farmer-participatory breeding. Seedling selection from an elite mother tree from Burliar, Nilgiris, Tamil Nadu. Bold nut, thick entire dark-red mace. About 2,000 fruits per tree by year 10. Female variety — needs a male tree nearby.
Quick facts
- Crop
- Nutmeg (Jaiphal)
- Type
- Grafted plant (improved variety)
- Season
- All seasons
- Maturity period
- First flowering from year 4 after grafting; full bearing by year 10–15
- 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 7,560 kg nuts + 1,512 kg mace/ha by year 10 (360 grafts/ha)
- Suitable soil
- Deep, well-drained clay loam, laterite or forest soil
- Release
- ICAR-IISR, Kozhikode, 2013 — farmer-participatory seedling selection from Burliar, Nilgiris, Tamil Nadu
About this variety
IISR Keralashree (2013) is the most productive nutmeg variety released in India, developed by ICAR-Indian Institute of Spices Research, Kozhikode, through farmer-participatory breeding — the first nutmeg variety in the world developed this way. It was selected from a seedling of an elite mother tree from Burliar in the Nilgiris, Tamil Nadu. It produces bold nuts and thick, entire dark-red mace, which fetches a premium. At 10 years of age with 360 grafts per hectare, it produced about 2,000 fruits per tree, yielding about 7,560 kg nuts and 1,512 kg mace per hectare — more than double the yield of IISR Viswashree at 8 years. First flowering can begin from about the fourth year after grafting. Low incidence of Diplodia fruit rot has been reported. Being a female variety, it requires male trees for 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; mace peeled, flattened and dried; 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 flowering from year 4 after grafting; full bearing by year 10–15
Expected yield
About 7,560 kg nuts + 1,512 kg mace/ha by year 10 (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 6–12 months before planting.
- Keep one confirmed male tree for every 10–12 female grafts for pollination.
- Prune overlapping branches for air circulation and to reduce fruit rot risk.
- Remove and destroy fallen rotten fruit promptly.
Advantages & considerations
Why farmers may choose it
- Highest-yielding released nutmeg variety in India
- Bold nut and thick, entire dark-red mace that fetches a premium
- Early flowering — from about year 4 after grafting
- Wide adaptability across nutmeg-growing regions
- Low Diplodia fruit rot incidence reported
Things to consider
- Female variety — must keep male trees for pollination
- First useful crop only from about year 6–7; full bearing by year 10–15
- Available mainly through IISR Kozhikode and KAU nurseries
- Needs shade, regular watering and good drainage
Suitable regions
Wide adaptability across all nutmeg-growing regions. Originally selected from Burliar, Nilgiris, Tamil Nadu.
- Kerala
- Tamil Nadu
Frequently asked questions
Is Keralashree the best nutmeg variety to plant?
For yield and mace quality, Keralashree is the top documented variety in India. If you also want every tree to bear fruit without worrying about male-female ratio, consider Konkan Sugandha — the only hermaphrodite variety. Many growers plant Keralashree as the main variety with a few male trees for pollination.
Sourced from: ICAR-IISR Kozhikode — Nutmeg varieties, TNAU Agritech Portal — Nutmeg, Spices Board India — Nutmeg. editorial policy.