Singapore Jack (NS-1)
An introduced early-bearing jackfruit. Kerala Agricultural University says it came from Sri Lanka, bears about 3 years after planting, is extremely precocious and gives fruit about the size of the common jack, with a yield of 250 fruits a plant a year. TNAU lists Singapore among Tamil Nadu's popular varieties.
Quick facts
- Type
- Grafted plant (improved variety)
- Season
- All seasons
- Starts bearing
- Bears about 3 years after planting (KAU); extremely precocious.
- Expected yield
- 250 fruits a plant a year (KAU); no kg-per-tree figure published
- Suitable soil
- All soils
- Disease resistance
- No special resistance widely documented
Actual yield depends on sowing time, soil, irrigation, weather, seed quality and crop management.
About this variety
Singapore Jack, also called Sri Lankan jack, is an introduced jackfruit that the Kerala Agricultural University (KAU) describes as extremely precocious: it bears about 3 years after planting. KAU says the fruit is about the same size as the common jack and gives a yield of 250 fruits a plant a year. It is one of two types KAU recommends for Kerala, alongside the firm-fleshed, sweet-scented Muttom Varikka. TNAU lists Singapore among the popular jackfruit varieties of Tamil Nadu, and Assam's 2021 package of practices lists Singapore Jack as a cultivar for the state. Many nursery sheets sell it as NS-1; we found no release record under that code. We found no trial with a fruit weight or a kg-per-tree figure for it.
Should you pick this variety?
Choose Singapore Jack if you want fruit as early as possible: KAU says it bears about 3 years after planting and calls it extremely precocious, and gives 250 fruits a plant a year. Do not choose it for a proven fruit weight or flesh type: KAU only says the fruit is about the size of the common jack. Choose Palur-1 instead if you want a documented crop (TNAU: about 80 fruits and 900 kg a tree) and an off-season Nov–Dec crop, though TNAU says its grafts take about 5 years to yield.
Sowing & cultivation
- Sowing timePlant grafts in June–December (TNAU). Cleft grafting for nursery plants is done in July–August on 4-month-old seedling rootstock.
- Spacing8 × 8 m (TNAU), in pits 1 m on each side. Assam's 2021 package of practices gives 10–12 m for its local and Singapore types.
- Sowing methodPlant a graft, not a seedling. TNAU fills each pit with topsoil mixed with 10 kg FYM and 1 kg neem cake. It prefers soil pH around 5.5 at planting; if the soil is more alkaline, TNAU treats the pit with 1% aluminium sulphate.
- IrrigationWater once a week until the plant is established. After that water only when needed (TNAU).
- FertilizerTNAU gives per tree, in two splits (May–June and September–October): a 1-year-old tree 10 kg FYM, 150 g N, 80 g P, 100 g K, with the same amount added each year. From the 6th year: 50 kg FYM, 750 g N, 400 g P, 500 g K.
- HarvestingTNAU says grafts start yielding in the 5th year (seedling trees in the 8th), and harvest runs March–July. TNAU puts the crop at 30–40 t/ha.
Soil & climate
Soil
- Suitable soil
- Deep, well-drained soil (TNAU). Rich, deep alluvial soil does best (Assam package).
- pH
- 5.5
Climate
- Climate
- The crop does well on the plains and up to 1,200 m elevation (TNAU).
Advantages & considerations
Why farmers may choose it
- Bears about 3 years after planting, among the earliest (KAU).
- Yield of 250 fruits a plant a year (KAU).
- Listed by KAU (Kerala), TNAU (Tamil Nadu) and Assam's package, so it is known in several states.
Things to consider
- No kg-per-tree or fruit-weight figure from a trial. KAU only says the fruit is the size of the common jack.
- Plants sold as NS-1 have no release record that we could find. Ask the nursery for the source tree.
Suitable regions
States this variety is recommended for — check locally, since a state can have more than one recommended zone.
- Kerala
- Karnataka
- Tamil Nadu
- Maharashtra
- West Bengal
Using the early fruit to carry the orchard
A jackfruit orchard is a long wait. TNAU says grafts yield from the 5th year and seedling trees from the 8th. Assam's package says 6 to 8 years. KAU says Singapore Jack bears about 3 years after planting.
Those two or three years are worth money. If you plant Singapore Jack in the first block, you start selling before your neighbours with other types, and the cash can pay for the second block of a slower, bigger variety.
Mix it in rows rather than in one corner. A common plan is to plant Singapore Jack as the early block and Palur-1 or a local type as the later block, with the same spacing. Keep a record of the first fruit weight from Singapore Jack, because the sources give you the fruit count but not the kilos.
Where the planting material comes from
This variety is a grafted plant: the variety on top, joined onto a rootstock below. Seed out of its fruit will not come up as this variety, so it cannot be kept as seed. Buy grafted plants from a registered nursery or a government farm, so the plant is true to the variety and free of disease.
How it compares with other varieties
Every Jackfruit (Kathal) variety with a page on this site, side by side. The row for this page is highlighted.
| Variety | Best for | Starts bearing | Yield | States |
|---|---|---|---|---|
| Gumless Jack | A low-latex jackfruit for farmers who cut and pack the bulbs and want a cleaner job, planted on trust in the trait until a trial says more | Grafted tree. NIF: the first graft (1988) began to yield about three years later. | No published trial yield. NIF reports that the first grafted tree gave 10 fruits in its second bearing year. | Karnataka |
| Konkan Prolific | A jackfruit named for the Konkan coast, best tried on a small block first because we found no verified yield, fruit or release data | Grafted tree. No bearing month or age is given for this variety. | No verified per-tree or per-hectare figure found. | Maharashtra, Goa |
| Palur-1 (PLR-1) | A documented, high-yielding jackfruit with a second crop in November–December, chosen for steady income from one tree | Regular crop April–June and an off-season crop November–December (TNAU). TNAU says jack grafts start yielding in the 5th year. | About 80 fruits, around 900 kg a tree a year; average fruit 12 kg (TNAU) | Tamil Nadu |
| Rudrakshi | A small-fruited local jackfruit for home orchards and local sale, planted on reputation rather than on a trial record | Grafted tree. TNAU says jack grafts start yielding in the 5th year; Assam's package says 6 to 8 years for its types. | No trial yield found. Assam's package gives 200–500 fruits a tree a year for its local and Singapore types in general. | Karnataka |
| Siddu Jack | A coppery-red, high-TSS jackfruit for direct sale of colourful bulbs, planted for colour and sweetness, with a yield still to be proven by trial | Grafted tree. Source tree about 35 years old. IIHR gives no bearing age for grafts. | IIHR estimate: about 450 fruits, 1,098 kg a tree (fruit about 2.44 kg). It is an estimate from the source tree, not a multi-location trial. | Karnataka |
| Singapore Jack (NS-1)this page | The early-bearing choice for farmers who cannot wait five years, planted for a first crop in about three | Bears about 3 years after planting (KAU); extremely precocious. | 250 fruits a plant a year (KAU); no kg-per-tree figure published | Kerala, Karnataka, Tamil Nadu, Maharashtra, 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 Jackfruit (Kathal) is selling for.
- Seed Rate CalculatorHow much seed your Jackfruit (Kathal) plot needs, corrected for the germination of the lot you bought.
- Seed Variety FinderFilter every Jackfruit (Kathal) variety on this site by state, season, duration and soil.
- Fertilizer CalculatorTurn the NPK recommendation for Jackfruit (Kathal) 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 Jackfruit (Kathal) rate in your nearest mandi, before you fix a price with a trader.
Subsidy and government support
Schemes that help with the cost of Jackfruit (Kathal) seed or planting material. Rules and the application route are on each scheme page.
Frequently asked questions
How soon does Singapore Jack bear?
KAU says it bears about 3 years after planting and calls it extremely precocious. TNAU says jackfruit grafts in general start yielding in the 5th year, and Assam's package gives 6 to 8 years for its types. So Singapore Jack is the earliest of the types we have records for. Good soil, water in the dry months and a healthy graft all help.
How many fruits does a Singapore Jack plant give?
KAU gives 250 fruits a plant a year. KAU says the fruit is about the size of the common jack, but gives no weight. Assam's package gives 200 to 500 fruits a tree a year for its Singapore and local types in general. So count fruits, not kilos, until you weigh your own harvest.
Is Singapore Jack the same as NS-1?
Many nursery sheets sell it as NS-1. We found no release record under that code from KAU, TNAU or ICAR. Treat NS-1 as a trade label for the Singapore type, and ask the nursery which tree its scions came from and how old that tree is.
Which Kerala jackfruit types does KAU recommend?
KAU recommends two types for Kerala: Muttom Varikka, which is firm-fleshed and sweet-scented, and the Singapore or Sri Lanka jack, which is introduced from Sri Lanka and extremely precocious. KAU also lists Sindhoor, a sweet variety with sunset-orange flakes and medium fruit of 11–12 kg that bears twice a year. Pick by what you sell.
What spacing should I give Singapore Jack?
TNAU plants jackfruit grafts at 8 × 8 m. Assam's package gives 10 to 12 m for Singapore Jack and local types, which is 69 to 100 trees a hectare. An early-bearing tree can still grow large, so give it room. Plan for a tree that will be 10 m or more across in later years.
Sourced from: Jack — TNAU Agritech Portal, Horticulture: Fruits, Jackfruit varieties — Kerala Agricultural University, Agri-Infotech Portal, Jackfruit — Package of Practices for Horticultural Crops of Assam, 2021 (AAU). editorial policy.