Effective Techniques for Harvesting, Transporting, and Preserving Mulberry Leaves

Mulberry leaves are the sole food source for silkworms (Bombyx mori), and the way these leaves are harvested, moved, and stored has a direct bearing on cocoon quality and silk yield. A poorly timed harvest or a careless transport run can undo months of careful mulberry cultivation. This post walks you through the key techniques for getting mulberry leaves from the garden to the rearing house in the best possible condition – with practical tips suited to the climate and farming systems of East and North-Eastern India.

Why leaf handling matters in sericulture 🔗

Silkworms consume roughly 94% of their total leaf intake during the fourth and fifth larval instars. That means the quality of leaves in these final stages largely decides whether you get plump, silk-rich cocoons or undersized, low-grade ones. According to the FAO’s documentation on mulberry cultivation in India, leaf quality and quantity per unit area have a direct bearing on cocoon harvest. Fresh, moisture-rich leaves supply the proteins, sugars, and water that silkworms need for healthy growth and efficient silk-protein synthesis. Once leaves start losing moisture or begin to ferment, their nutritional value drops sharply – and silkworms are far more sensitive to this decline than most people realise.

Timing the harvest: matching leaves to silkworm needs 🔗

Leaf harvesting in mulberry sericulture is not a single annual event. Under irrigated conditions, mulberry plants can yield up to five harvests per year. Shoots are typically harvested at intervals of 10-12 weeks, though the exact gap depends on the variety, water availability, and climatic conditions in your region. In parts of East and North-Eastern India – where high humidity and seasonal temperature swings are common – adjusting your harvest calendar to local weather patterns is essential.

Harvest frequency and pruning cycles 🔗

The first crop is usually ready about six months after planting, once the mulberry is well established. As noted by the FAO’s mulberry guide, two more crops can be harvested during the first year using the leaf-picking method, and full pruning is done after one year at the onset of the next monsoon. After that initial year, harvests follow a regular cycle tied to the silkworm rearing schedule. In the leaf-picking system, the first harvest takes place roughly 10 weeks after bottom pruning, and subsequent pickings occur at 7-8 week intervals. In the shoot-harvest system, the interval stretches to about 10 weeks per cycle, yielding around five harvests annually.

Selecting leaves at the right maturity 🔗

Not every leaf on a mulberry branch is equally suitable. For young-age (chawki) silkworms, tender leaves from near the shoot tip – typically the 2nd to 4th leaf from the top – are ideal. These are softer, higher in protein, and easier for small larvae to consume. For late-age silkworms (4th and 5th instars), mature but not over-aged leaves from shoots that are 55-65 days old provide the best balance of nutrition and digestibility. Avoid yellowing, over-mature, or diseased leaves – they carry less moisture and lower nutritive value.

Best practices for harvesting mulberry leaves 🔗

The time of day you pick leaves matters more than many farmers realise. As the day warms up, mulberry leaves lose moisture through transpiration, becoming less succulent and less palatable for silkworms. According to IndiaAgroNet’s sericulture resource, leaves should be harvested in the early hours of the day because moisture content declines with active transpiration as temperatures rise. The recommended window is 6:00-8:00 AM or after 4:00 PM during peak summer months.

Leaf picking versus shoot harvesting 🔗

There are two primary methods of harvesting mulberry leaves, each with its own trade-offs:

Leaf picking is the most common method across India. Individual leaves are plucked by hand, starting from the tip of the branch and working downward. This approach lets you selectively harvest leaves of the right maturity for different silkworm stages. However, it is highly labour-intensive. As Vedantu’s moriculture guide explains, each leaf is picked from an individual plant, requiring significant time and manpower. Leaves harvested with the petiole (stalk) intact retain their moisture content better.

Shoot or branch harvesting involves cutting the entire branch or shoot close to the ground. This method is faster, more cost-effective, and keeps leaves attached to the stem – which means they stay fresh for a longer duration. It is generally used for feeding late-age silkworms after the 3rd moult. According to the IndiaAgroNet resource, whole shoot harvest reduces labour costs significantly and allows around five harvests per year.

Sharp, clean tools – such as pruning saws or secateurs – should always be used for shoot harvesting to avoid damaging the plant’s bark or stem. Ragged cuts from dull tools can invite disease and pest infestations.

Maintaining plant health during harvest 🔗

Regardless of the method you choose, it is important to maintain a stump height of 8-10 inches (20-25 cm) above ground level after pruning. Cutting too low can weaken the plant and reduce its productive lifespan. Mulberry is a perennial crop that can remain productive for 10-15 years, so sustainable harvesting practices protect your long-term investment.

Transporting mulberry leaves without losing quality 🔗

The journey from the mulberry garden to the silkworm rearing house is where many sericulturists unknowingly lose leaf quality. Leaves are living tissues – they continue to respire and lose moisture after being cut. Every hour of delay or rough handling reduces their feeding value.

Choosing the right containers 🔗

Bamboo baskets remain one of the most effective containers for transporting mulberry leaves in small to medium operations. They allow natural air circulation, preventing the buildup of heat and humidity that can trigger fermentation or fungal growth. Plastic bags or sealed containers should be avoided – they trap moisture and create conditions for rapid spoilage.

Covering the load 🔗

A damp gunny cloth draped over leaf-filled baskets is the standard practice for transport. This cover creates a humid microenvironment around the leaves, slowing down moisture loss while also shielding them from direct sunlight and wind. As described by the Neotia University’s sericulture manual, leaves after harvesting should be transported in wet gunny cloth and preserved carefully to maintain freshness. The cloth should be moist – not dripping wet – since excess water can damage leaves or promote fungal issues.

Minimising transport time 🔗

Ideally, leaves should reach the rearing house within 2-4 hours of harvesting. Longer transit times call for extra precautions, such as using ice packs wrapped in cloth (in extreme heat) or transporting during cooler hours. Building your rearing house close to the mulberry garden is one of the simplest ways to cut down on transport-related quality loss.

Preserving mulberry leaves until feeding time 🔗

Even after leaves arrive at the rearing house, proper storage is critical. Freshly harvested mulberry leaves have a limited shelf life – under optimal conditions, they maintain acceptable quality for roughly 12-24 hours. Beyond that, nutritional degradation accelerates and the risk of spoilage rises.

The wet gunny cloth method 🔗

The most widely used and effective preservation technique is simple: spread the leaves in thin layers and cover them with a damp gunny cloth. This maintains humidity around the leaves without waterlogging them. The cloth should be re-dampened periodically to keep it consistently moist. In hot and dry climates, some farmers use a leaf preservation chamber – essentially a wooden enclosure lined with gunny cloth that is kept wet by regular spraying, as noted in the Neotia University sericulture manual.

Temperature and humidity control 🔗

Store leaves in a cool, clean, and well-ventilated room. The ideal storage temperature is between 20-25°C, and relative humidity should stay in the range of 85-90%. Higher temperatures speed up metabolic activity in the harvested leaves, leading to faster deterioration. At the same time, proper air circulation is essential – stagnant air causes a buildup of gases from leaf respiration, which can trigger fermentation. But avoid strong drafts, as they accelerate drying.

Seasonal considerations for preservation 🔗

Different seasons pose different challenges. During summer, high temperatures make leaves wilt faster, so you may need to harvest in smaller quantities more frequently rather than storing large batches. During the monsoon season, excess humidity increases the risk of fungal contamination, requiring extra attention to ventilation and cleanliness. Winter can make leaves tough and less digestible; gradual temperature adjustment before feeding helps maintain palatability.

Recognising signs of leaf quality decline 🔗

Knowing when stored leaves are past their prime prevents you from feeding substandard foliage to silkworms – which can cause digestive stress, slower growth, and poorer cocoon quality.

Colour changes: Fresh leaves are a vibrant, even green. Yellowing, brown spots, or darkened patches indicate aging, moisture loss, or microbial infection. Discoloured leaves should be removed immediately to prevent contamination of healthy stock.

Texture: Properly preserved leaves feel firm and slightly moist. If they have turned wilted, brittle, or slimy, they have lost both moisture and nutritional value.

Odour: Fresh mulberry leaves have a mild, characteristic aroma. Any sour, fermented, or off-putting smell is a clear sign of spoilage. Fermented leaves are not just nutritionally poor – they can actively harm silkworms.

Economic impact of proper leaf management 🔗

Investing time and effort in correct harvesting, transportation, and preservation techniques pays off directly at the cocoon market. Research in sericulture has shown that proper leaf handling can boost cocoon production by 15-20% compared to careless practices. That improvement compounds across multiple rearing cycles each year. Healthy silkworms fed with fresh, high-quality leaves produce cocoons with higher silk content and better fibre quality, which fetch better market prices. Reduced silkworm mortality also cuts the economic losses that come from disease and poor nutrition during rearing.

Quick-reference summary of key practices 🔗

Harvest timing: Early morning (6-8 AM) or late evening; avoid midday heat.
Harvest frequency: Up to five harvests per year under irrigated conditions, at 10-12 week intervals for shoot harvesting.
Leaf selection: Tender leaves for chawki worms; mature (55-65 day) leaves for late-age worms. Avoid yellow or diseased leaves.
Transport: Use bamboo baskets covered with damp gunny cloth; deliver within 2-4 hours.
Preservation: Store in thin layers under damp gunny cloth at 20-25°C and 85-90% RH; use within 12-24 hours.
Hygiene: Keep the storage area clean and disinfected; remove deteriorating leaves promptly.

What do you think? How do the specific climatic challenges of East and North-Eastern India – such as high monsoon humidity or winter cold spells – affect your leaf handling practices? And could small-scale mechanisation of harvesting improve efficiency without compromising leaf quality for silkworm rearing?

References

1. https://www.fao.org/4/x9895e/x9895e04.htm
2. https://indiaagronet.com/indiaagronet/sericulture/contents/mori.htm
3. https://www.vedantu.com/biology/moriculture
4. https://www.tnu.in/wp-content/uploads/2021/09/12.-ELP_812_CS_MANUAL-1.pdf