Propagation Methods for Sapota and Jackfruit

Sapota (Achras zapota L.) and jackfruit (Artocarpus heterophyllus) are two commercially important tropical fruit crops widely cultivated across India and Southeast Asia. While both can be raised from seeds, the nursery industry has long shifted focus to vegetative propagation – and for good reason. Seedling trees are slow, variable, and uneconomical for commercial orchards. Knowing the right propagation method for each crop is the first practical decision any serious grower or horticulture student must make.

Sapota propagation: sexual vs. vegetative 🔗

Sapota can be raised both sexually (from seeds) and asexually (through various grafting and layering techniques). Each approach has its place, but they serve very different purposes.

Seed propagation (sexual) 🔗

Sapota seeds are recalcitrant – they lose viability quickly if exposed to heat or allowed to dry out. Large seeds from large, high-quality fruits are preferred for sowing. While germination is fairly reliable, the problem lies in what comes after. Research published in the Indian Journal of Agricultural Research confirms that seed-propagated sapota trees bear fruit only after 8-10 years, and even then the quality and yield of fruits vary considerably between individual plants due to high genetic heterozygosity. This makes seed propagation unsuitable for commercial nurseries. Its use is largely confined to crop improvement and breeding programmes where genetic variability is actually desirable.

Vegetative (asexual) propagation 🔗

Vegetatively propagated sapota plants come into bearing in 4-5 years, maintain genetic uniformity, and produce fruit of known quality – clear advantages for commercial cultivation. Several vegetative methods are in use across different agroclimatic regions of India.

Inarching: the preferred commercial method 🔗

Inarching, also called approach grafting, is the most widely practiced propagation method for sapota in India, especially by private nurseries. In inarching, both the rootstock and scion remain attached to their respective parent plants throughout the union process – the scion is never severed until the graft has taken successfully. This continuity is precisely what makes it reliable for species like sapota, where the gummy latex can otherwise interfere with graft union.

Rootstocks used for inarching are typically 2-3 year old Khirni (Manilkara hexandra) or Rayan seedlings raised in polythene bags, at least 45-60 cm in height and 1 cm in diameter. The mother plant selected as a scion source should be a true-to-type, vigorous plant aged 10-15 years. A 1-1.5 year old branch of pencil thickness from the mother plant is brought close to the rootstock, and matching cuts of 5-6 cm length are made on both. The exposed cambium layers are pressed together and wrapped tightly with a polythene strip.

The grafting union typically takes about 2-2.5 months, but separation from the mother plant should not happen before 3-4 months. The rootstock is watered daily for the first two weeks, then every three days. Once separated, the graft is hardened off in a nursery shade before field planting. Inarching carried out during February-March tends to show higher success rates and requires a shorter nursery period compared to the rainy season. Studies at Punjab Agricultural University found that inarching recorded the maximum average graft survival of 70.56% among all propagation methods tested – though its benefit-cost ratio is lower than side or veneer grafting due to higher labour costs.

Other vegetative methods for sapota 🔗

Air layering (gootee layering) 🔗

Air layering in sapota is performed in June. A healthy 1-2 year old shoot of 45-60 cm length and pencil thickness is selected, and a 3 cm wide ring of bark is removed just below a bud. Rooting hormones (IBA and NAA at 50 mg each in lanolin paste) are applied, and the area is packed with moist sphagnum moss and wrapped with polythene to retain moisture. Light brown roots become visible through the wrapping within about four months.

Air layering does not require a rootstock and is relatively inexpensive, making it cost-effective for small-scale nurseries. However, it has a significant drawback: plants produced by air layering have shallow root systems, making them susceptible to strong winds and drought stress. This limits their suitability for exposed field conditions.

Softwood grafting 🔗

Softwood grafting (also called wedge or cleft grafting) is increasingly popular, particularly in regions with moderate temperatures and high humidity. The scion should be a terminal, non-flowering shoot of 3-4 months maturity, defoliated at least 7 days before grafting while still on the mother plant. Defoliation causes swelling of dormant buds, which improves graft success. The scion is shaped into a wedge and inserted into a cleft made in the Rayan rootstock, then secured with polythene strip. This method works best in regions with moderate temperatures and high relative humidity, which prevent the scion stick from drying out.

Veneer and side grafting 🔗

Veneer and side grafting using mature scion sticks are effective across variable climatic conditions and are commonly used alongside softwood grafting in south and east India. Research from South Bengal found high success rates with veneer grafting during September and November, while conditions in Andhra Pradesh favoured August. The best method and optimal timing thus depend on local climate.

Budding 🔗

Budding involves inserting a single bud from the desired variety into a T-shaped incision on the rootstock. It is practiced to a limited extent in sapota and follows the same rootstock preference – Khirni seedlings. It is less labour-intensive than inarching but typically shows lower success rates under field conditions.

Stone (epicotyl) grafting 🔗

Stone grafting, also referred to as epicotyl grafting in some literature, uses very young seedlings still carrying the cotyledons (seed leaves) as rootstocks. A wedge-cut scion is inserted into the split stem of the young seedling. This method is faster and less expensive to set up but requires careful management of humidity and shade during the early stages of healing.

Why cuttings don’t work in sapota 🔗

It is worth noting a common failure point: propagation through stem cuttings is not successful in sapota, even when treated with plant growth regulators such as IBA. The high phenolic content and latex exudation in sapota plant tissue inhibit root initiation. Tissue culture has been explored but remains confined to academic trials due to technical complexities.

Jackfruit propagation: seeds first, grafting gaining ground 🔗

Jackfruit is a highly cross-pollinated crop. This biological reality shapes everything about how it is propagated commercially.

Seed propagation (sexual) 🔗

Jackfruit seeds are recalcitrant and must be sown immediately after extraction from the fruit, as they cannot be stored for long. Soaking seeds for 24 hours in water before sowing speeds up germination, which otherwise takes 3-8 weeks. Seeds should be collected from healthy, prolific mother trees bearing fruits with desirable characteristics, and only large, well-formed seeds should be selected.

Despite the simplicity of seed propagation, it has commercial limitations. Because jackfruit is highly cross-pollinated, seedling populations show wide genetic variability – trees are not genetically identical to the mother plant. This leads to inconsistency in fruit quality, size, and flavour. Seedling trees are also taller and take longer to begin bearing. For these reasons, vegetative propagation is increasingly adopted where superior clonal varieties are to be multiplied.

Vegetative propagation methods in jackfruit 🔗

Epicotyl grafting 🔗

Epicotyl grafting is one of the most practically relevant vegetative methods for jackfruit. It uses very young seedlings – still in the cotyledon stage – as rootstocks. Jackfruit seeds are sown in polybags in the first week of July. Once seedlings reach 12-14 cm in height, they serve as rootstocks. A wedge of about 4 cm is prepared at the base of the scion and inserted into the split epicotyl region of the rootstock, then tied firmly with polythene strips.

Research conducted at Bangladesh Agricultural University found that 14-day-old rootstocks gave the highest grafting success (39.84%) and survival (34.41%), while grafting in June produced the best results overall, with a success rate of 49.55% and survival of 45.47%. The combination of a 14-day-old rootstock grafted in June yielded the highest success rate of 57.33%. October grafting showed the lowest performance, likely due to less favourable temperature and humidity conditions.

Veneer grafting 🔗

The modified veneer graft is among the most successful methods for jackfruit. It requires active scions of 10-15 cm with a swollen terminal bud. Long, shallow veneer cuts are made on both the rootstock and scion, exposing the cambium, and the last fully expanded leaf on the scion is retained. Veneer grafting tends to be most successful during spring and summer months (March to May). Studies in subtropical Assam found wedge grafting during December-January to give the highest survivability (92.40-93.60%), with side grafting in the same period giving comparable results (88.40-89.40%).

Air layering 🔗

Air layering can be used to propagate jackfruit and has been distributed in India as a means of ensuring early and consistent bearing of fruits of known quality. Rooting-promoting hormones are applied to improve success rates. The method avoids the transplanting problem associated with jackfruit seedlings, whose long, delicate taproots make them difficult to move once established.

Stem cuttings 🔗

Stem cuttings are possible for jackfruit but require careful use of rooting hormones at appropriate concentrations. The method is less commonly used compared to grafting and air layering and is generally reserved for situations where other propagation material is unavailable. Success rates are variable and depend heavily on environmental conditions and the maturity of the cutting.

Budding 🔗

Bud grafting is also practised in jackfruit, depending on the time of year and availability of budwood. T-budding or patch budding approaches are used, with compatible jackfruit seedlings as rootstocks. As with other grafting methods in jackfruit, success rates remain variable and can range from 0-90% depending on technique, season, and post-graft management.

Choosing the right method: a practical summary 🔗

For sapota, inarching remains the benchmark for commercial nurseries despite its high labour input – the graft survival rate is simply more reliable. Softwood and veneer grafting are gaining ground as cost-effective alternatives, especially where skilled labour for inarching is limited. Air layering is suitable for small-scale or farm-level propagation but should not be relied upon for large, exposed orchards due to the shallow root system it produces.

For jackfruit, seed propagation remains common because vegetative methods in this crop are genuinely more challenging due to its cross-pollinated, latex-rich nature. However, where superior selections need to be clonally multiplied, epicotyl grafting (especially in June using 14-day-old rootstocks) and modified veneer grafting offer the most consistent results. Grafted jackfruit trees bear fruit in just two to three years after planting compared to much longer waiting periods with seedling trees – a compelling economic argument for investing in the extra effort that vegetative propagation demands.

What do you think? Given that inarching in sapota achieves higher graft survival but at a higher labour cost compared to veneer or side grafting – which factor would you prioritise when setting up a commercial sapota nursery? And considering the challenges of vegetative propagation in jackfruit, do you think epicotyl grafting is practical enough to replace seed-based nursery production at scale?

References

1. https://www.arccjournals.com/journal/indian-journal-of-agricultural-research/A-6287
2. https://www.horticultureguruji.in/to-study-the-plant-propagation-by-inarching/
3. https://nhb.gov.in/pdf/fruits/sapota/sap010.pdf
4. https://www.researchgate.net/publication/347874114_Propagation_Studies_in_Sapodilla_Manilkara_zapota_L_P_Royen_A_Review
5. https://www.cropsreview.com/growing-jackfruit/
6. https://www.researchgate.net/publication/284809809_Softwood_grafting_in_jackfruit
7. https://www.agrifarming.in/jackfruit-grafting-methods-pruning-methods-training
8. https://scialert.net/fulltext/?doi=ajps.2003.1047.1051
9. https://nt.gov.au/environment/home-gardens/growing-vegetables-at-home/jackfruit
10. https://www.sciencedirect.com/science/article/abs/pii/S0304423823007641