Gumless Jack
A low-latex ('gumless') jackfruit. Two origins are reported: a Karnataka farmer's grafted latexless tree (National Innovation Foundation) and an IIHR gumless type. We found no formal release record, and no fruit-weight or yield figure from a trial.
Quick facts
- Type
- Grafted plant (improved selection)
- Season
- All seasons
- Starts bearing
- Grafted tree. NIF: the first graft (1988) began to yield about three years later.
- Expected yield
- No published trial yield. NIF reports that the first grafted tree gave 10 fruits in its second bearing year.
- 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
Gumless Jack is a jackfruit chosen for low latex. Two origins are reported. The National Innovation Foundation (NIF) profiles Harish Chandra Shetty, a Karnataka farmer who grafted a tasty low-gum scion on an old jack tree in 1988, after many failed attempts. The graft began to yield about three years later, and NIF says he has distributed over one lakh plants in Karnataka, Tamil Nadu, Kerala and Andhra Pradesh. A separate secondary source describes a pre-release gumless type at ICAR-IIHR Bengaluru with medium-to-low latex. We found no formal release record for either, and no trial figure for fruit weight or yield. The only firm claim is the one in the name: it bleeds less latex when cut.
Should you pick this variety?
Choose Gumless Jack if you cut jackfruit, sell bulbs, or make chips and the latex slows your work. That is the one thing every source agrees on. Do not choose it for a stated yield or fruit size: we found none from a trial. Choose Palur-1 instead if you want a documented crop (TNAU gives about 80 fruits, 900 kg a tree, 12 kg a fruit) and an off-season Nov–Dec crop. Plant a few Gumless Jack trees first and weigh their fruit.
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
- Less latex when the fruit is cut, so cutting and cleaning are easier.
- Grafted plants are sold by nurseries; NIF reports over a lakh plants distributed.
- A farmer's tree began yielding about three years after grafting (NIF).
Things to consider
- No release record and no trial figure for fruit weight or yield, so test a few trees before planting a block.
- Several plants sold as gumless may not be the same type. Buy only from a nursery that names the source tree.
Suitable regions
States this variety is recommended for — check locally, since a state can have more than one recommended zone.
- Karnataka
Check the latex yourself before you rely on it
The whole case for Gumless Jack is one trait: less latex on the knife and the hands. That trait is real in the stories we found. NIF describes the first tree as totally gumless, and a secondary source describes the IIHR type as medium-to-low latex.
What we could not find is a trial that compares latex, fruit weight and yield with other jackfruit trees under the same conditions. So how much extra work you save cannot be stated.
Test it before you plant an orchard. Cut one fruit from the nursery's source tree, and one from a normal tree. Time the cutting and count how much oil or gloves you use. If the difference is big enough to pay for the extra plant cost, go ahead. If the nursery will not let you see a fruiting tree, buy fewer plants.
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 Jackthis page | 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) | 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
Who developed Gumless Jack?
Two origins are reported. The National Innovation Foundation says Harish Chandra Shetty, a Karnataka farmer, grafted a tasty low-gum scion on an old jack tree in 1988, on his tenth experimental attempt. A secondary source describes a gumless type at ICAR-IIHR Bengaluru with medium-to-low latex. We found no release notification for either, so ask the nursery which source its plants come from.
How soon does a Gumless Jack graft bear?
NIF says the first graft, made in 1988, began to yield about three years later, though the fruit dropped young in the first year and the tree bore ten fruits the next year. For jackfruit in general, TNAU says grafts start yielding in the 5th year and seedling trees in the 8th. Plan on 3 to 5 years.
Is Gumless Jack really free of latex?
NIF says the fruits were totally gumless, with very good taste and colour. The IIHR type is described as medium-to-low latex, so some latex remains. A planters' guide notes that most of the latex is in the core, so even a gumless type is easier to cut if you remove the core early. Cut one fruit from your own tree before you promise a buyer anything.
Can I plant Gumless Jack in Assam or the north?
NIF reports plants going to Karnataka, Tamil Nadu, Kerala and Andhra Pradesh. We found no record from Assam, Uttar Pradesh or Bihar. Jackfruit does best in warm, humid places and TNAU says up to 1,200 m elevation. Try a few grafts in your own soil for two seasons before you commit.
Sourced from: Jack — TNAU Agritech Portal, Horticulture: Fruits, Latexless jackfruit — National Innovation Foundation. editorial policy.