The Role of Pollarding in Muga Food Plant Cultivation

Muga silk – often called India’s “golden silk” – is one of the rarest and most valuable textiles in the world. It comes exclusively from the silkworm Antheraea assamensis, which feeds primarily on Som (Persea bombycina) and Soalu (Litsea polyantha) trees in northeast India. But here’s the thing: the quality of Muga silk depends heavily on the quality of leaves these host plants produce. And that’s where pollarding enters the picture. This age-old tree management technique plays a critical role in keeping Muga food plants productive, manageable, and healthy – ultimately supporting the entire Muga silk value chain.

What is pollarding? 🔗

Pollarding is a systematic pruning technique in which the upper branches of a tree are cut back to the main trunk or to a few large scaffold branches. This encourages the tree to produce a dense head of new foliage and branches from the cut points. Over time, the cut areas develop characteristic knob-like structures called pollard heads, which become the source of repeated regrowth year after year.

The technique has deep historical roots. In Europe, pollarding has been practised since medieval times for purposes ranging from livestock fodder production to fencing material. The key distinction between pollarding and coppicing – another similar practice – is height. In coppicing, trees are cut at ground level, whereas in pollarding, cuts are made higher up on the trunk, typically well above the reach of grazing animals. This protects new shoots from being browsed or damaged.

In the context of Muga sericulture, pollarding serves a very specific purpose: it keeps food plants at an ideal height for silkworm rearing while maximising the production of tender, nutritious leaves.

Why muga food plants need pollarding 🔗

Som and Soalu trees, if left to grow naturally, can reach heights of 50 to 60 feet. At that size, managing silkworm rearing becomes nearly impossible. The leaves on very tall trees tend to become rough, coarse, and small. They are also more prone to damage from diseases and insect pests. Rearers cannot easily place or monitor silkworms on branches that are dozens of feet above the ground.

According to Central Silk Board guidelines, periodical pollarding or heavy pruning should be practised after rearing to maintain the canopy at 10-12 feet for effective management. This height range strikes a balance – it is tall enough for the trees to produce abundant foliage, yet low enough for farmers to access branches during rearing, harvesting of cocoons, and pest inspection.

The objectives of pollarding Muga food plants, as outlined in sericulture training literature, include increasing foliage production, removing dead or diseased parts, giving the plant a desirable shape, controlling plant height, and establishing a functional balance between different organs of the plant.

When and how pollarding is carried out 🔗

Pollarding of Muga food plants is not done immediately after planting. The trees need time to establish a strong root system and trunk before they can withstand the stress of heavy pruning. Typically, pollarding is carried out after the trees reach 6-7 years of age.

Timing 🔗

The recommended period for pollarding Som plants is September-October. This timing is important because it falls after the major rearing seasons, giving the tree enough time to recover and produce fresh foliage before the next rearing cycle begins. The Muga silkworm has six broods per year, so timing the pollarding correctly ensures minimal disruption to the silk production calendar.

Cutting height 🔗

The main stem or trunk is cut at a height of approximately 5 feet (about 1.5 metres) from the ground. This creates a framework from which new branches emerge. The Central Silk Board recommends maintaining the resulting canopy at 10-12 feet through subsequent management, using a step-up and step-down method of pruning in the years following the initial pollarding cut.

The step-up / step-down method 🔗

This is a cyclical pruning approach used in Muga food plant management. In the step-up phase, the tree is allowed to grow somewhat taller, with selective pruning of side branches. In the step-down phase, the canopy is brought back to a lower height through heavier cuts. This alternating pattern prevents the tree from becoming excessively stressed while still controlling its overall size. The method also promotes even distribution of foliage across the canopy, which is essential for uniform silkworm rearing.

Benefits of pollarding for muga silk farming 🔗

The advantages of pollarding go well beyond simply keeping trees short. Here are the specific ways this practice supports Muga silk production:

Increased foliage production 🔗

When the upper branches are cut, the tree redirects its energy into producing multiple new shoots from the pollard heads. These new shoots bear tender, young leaves that are far more nutritious and palatable for Muga silkworms than the tough, mature leaves found on unpruned trees. Higher foliage quantity and quality directly translate to better silkworm survival and superior cocoon output.

Improved leaf quality 🔗

Research has shown that younger leaves have higher moisture retention capacity, which positively correlates with higher survival rates of early-instar Muga silkworms. Pollarding essentially resets the leaf age on the tree – the regrowth consists predominantly of young, tender leaves with better nutritional profiles.

Disease and pest management 🔗

Pollarding provides a systematic opportunity to remove diseased and dead branches before problems spread to the rest of the tree. Major foliar diseases of Som include leaf spot caused by the fungus Phyllosticta perseae, leaf blight, grey blight, and red rust. According to Central Muga Eri Research & Training Institute data, diseases can cause a leaf yield loss of around 16% of total annual production. By cutting away affected parts during pollarding, farmers can significantly reduce disease load.

Pollarding also helps manage pest issues such as the stem borer (Zeuzera indica), which bores into tree trunks, and Cricula (Cricula trifenestrata), which feeds voraciously on leaves. The improved visibility that comes with a well-maintained, lower canopy makes it easier to detect and address these pest problems early.

Easier silkworm rearing management 🔗

A tree maintained at 10-12 feet through regular pollarding is far easier to work with than a 40-foot giant. Farmers can place silkworm larvae on branches more easily, monitor their feeding and growth, protect them from predators, and harvest cocoons without climbing dangerously tall trees. This practical benefit is especially important for the approximately 34,000 families that the Wiley-published research review on Muga food plants estimates are actively involved in Muga culture.

Extended productive lifespan of trees 🔗

Pollarding helps trees live longer by maintaining them in a partially juvenile state. The practice reduces the weight and wind resistance of the upper canopy, lowering the risk of structural failure. A healthy, well-pollarded Som or Soalu tree can remain productive for decades, providing a sustained supply of leaves for silkworm rearing across many generations of farmers.

How pollarding fits into the broader cultivation cycle 🔗

Pollarding is not a standalone activity – it is one part of a comprehensive package of practices for Muga food plant cultivation. Understanding where it fits in the overall cycle is important.

Nursery and planting phase (years 0-3) 🔗

Som and Soalu plants are propagated through seeds, which are collected during May-June. Seeds are sown in raised nursery beds, and seedlings are transplanted to the field at recommended spacings – 4×4 metres for Som and 5×5 metres for Soalu – once they are about three months old and roughly a foot tall. During these early years, the focus is on establishment: watering, weeding, manuring with farmyard manure, and protecting seedlings from pests.

Training phase (years 1-6) 🔗

From the seedling stage, the plant’s growth is guided through a technique called tip nipping. When seedlings reach about 12 inches, the apical tips with 3-4 leaves are pinched off by hand. This activates axillary buds, and within about 20 days, new branches emerge. Repeated tip nipping at six-month intervals produces an umbrella-shaped crown with multiple branches and slower vertical growth. This early training lays the foundation for effective pollarding later on.

First pollarding (year 6-7) 🔗

Once the tree has developed a sturdy trunk and strong root system, the first pollarding is done. The main trunk is cut at about 5 feet, and subsequent growth is managed through the step-up/step-down method to maintain canopy height at 10-12 feet.

Ongoing management (year 7 onwards) 🔗

After the initial pollarding, the trees enter a cycle of rearing and post-rearing maintenance. After each silkworm rearing season, light pruning is done. Periodical heavy pruning or re-pollarding follows as needed. Alongside pruning, farmers apply manure, manage weeds, and control pests and diseases to keep the trees in optimal condition.

Common challenges and mistakes in pollarding muga food plants 🔗

While pollarding is highly beneficial, it must be done correctly. Several common pitfalls can reduce its effectiveness or even harm the trees.

Pollarding too early 🔗

Cutting back a tree before it has developed adequate root and trunk strength – generally before 6 years of age – can severely weaken it. Young trees may not have the energy reserves to regenerate effectively after heavy pruning.

Incorrect cutting height or angle 🔗

Cuts that are too low can damage the main trunk irreparably. Cuts that are too high defeat the purpose of height control. Additionally, rough or jagged cuts create entry points for fungal infections. Clean cuts made with sharp tools heal faster and reduce the risk of decay.

Neglecting post-pollarding care 🔗

Pollarding without follow-up management leads to uncontrolled regrowth. The new shoots can become excessively dense or grow in undesirable directions, creating a canopy that is difficult to manage for rearing purposes. Regular selective pruning of regrowth is essential.

Ignoring pest and disease inspection 🔗

Pollarding creates open wounds on the tree. If these are not monitored, they can become entry points for stem borers or fungal pathogens. Wound care and vigilant post-pollarding inspection are important steps that farmers should not skip.

Pollarding and sustainability of muga silk production 🔗

The Muga silk industry faces real challenges. Deforestation has reduced the availability of Som and Soalu trees. Climate change is making weather patterns less predictable. The Assam Directorate of Sericulture and agencies like the Central Silk Board have been promoting systematic plantation and scientific management of food plants as a way to counter these threats.

Pollarding fits directly into this sustainability agenda. By keeping existing trees productive for longer periods, it reduces the need to constantly plant new trees. By improving leaf yield per tree, it means farmers can produce more silk from the same land area. And by enabling better pest and disease management, it reduces crop losses that might otherwise push farmers away from Muga culture entirely.

Approximately 10,000 hectares of land are currently used for cultivation of Muga silk food plants across northeast India. With proper pollarding and management practices, the productivity of this existing plantation base can be significantly enhanced – a far more practical approach than trying to expand into new land that may not be available.

The connection between pollarding and silk quality 🔗

It is worth emphasising that the link between pollarding and the final silk product is not indirect – it is very direct. The host plants significantly influence the growth, nutritional intake, and silk production of the Muga silkworm. Cocoons produced by silkworms fed on high-quality Som leaves have better shell weight, higher silk ratio, and superior reelability compared to those reared on poor-quality foliage.

By ensuring that trees produce abundant, tender, nutrient-rich leaves through regular pollarding, farmers are effectively controlling the quality of the raw material at the very beginning of the silk production chain. This is why organisations like the Central Silk Board conduct field days and training programmes specifically focused on host plant management techniques including pruning and pollarding.

Key takeaways 🔗

Pollarding is far more than a simple pruning exercise for Muga food plants. It is a scientifically backed management practice that controls tree height, boosts foliage production, improves leaf quality, enables effective pest and disease management, and supports the long-term sustainability of Muga silk farming. When done at the right time (September-October), at the right stage (after 6-7 years of growth), and at the right height (about 5 feet, maintaining canopy at 10-12 feet), pollarding transforms unwieldy forest trees into efficient, productive food plants for one of the world’s most precious silkworms.

For the thousands of families in Assam and the broader northeast whose livelihoods depend on Muga silk, mastering the art and science of pollarding is not optional – it is foundational to their success.

What do you think? Could modern agroforestry techniques further improve how we manage Muga food plants, or does the traditional knowledge of Assamese farmers already hold most of the answers? How important is host plant management in determining the future of India’s golden silk industry?

References

1. https://en.wikipedia.org/wiki/Pollarding
2. https://silks.csb.gov.in/keonjhar/muga-food-plant-production-technology/
3. https://hbmahesh.weebly.com/uploads/3/4/2/2/3422804/non_mulberry_food_plant_cultivation..pdf
4. https://indianculture.gov.in/stories/muga-silk
5. https://www.wisdomlib.org/science/journal/world-journal-of-pharmaceutical-research/d/doc1366704.html
6. https://cmerti.res.in/faq/
7. https://onlinelibrary.wiley.com/doi/10.1111/eea.13021
8. https://www.atlantaarbor.com/blog/pollarding/
9. https://sericulture.assam.gov.in/portlet-innerpage/food-plants-of-muga-silkworm
10. https://www.researchgate.net/figure/Primary-and-secondary-food-plants-of-Muga-silkworms-A-Persea-bombycina-B-Litsea_fig3_348878032
11. https://theassamrising.com/assam/muga-field-day-organised-to-empower-muga-farmers-in-assam-1500404