Maximizing Chawki Leaf Yield and Quality in Mulberry Gardens

In sericulture, the success of silk production starts long before the cocoon is spun. It begins in the chawki mulberry garden – a specialized plot designed to grow tender, nutrient-dense leaves exclusively for young silkworms. The yield and quality of chawki leaf directly determine how many disease-free layings (dfls) a farmer can rear, and ultimately, how good the cocoon harvest will be. Getting both right – high tonnage and superior nutritional content – is what separates a productive sericulture operation from an underperforming one.

What is a chawki mulberry garden? 🔗

A chawki mulberry garden is a dedicated mulberry plantation raised separately from the main garden used for late-age silkworm rearing. The reason for maintaining a separate garden is simple: young silkworms (first and second instars) have very different nutritional needs compared to older worms. They need leaves that are tender, high in moisture, rich in protein, and easy to digest. A general-purpose mulberry garden, which is managed for coarser, mature leaf production, simply cannot supply leaf of this quality in reliable quantities.

The concept of the chawki garden revolves around cultivating specific mulberry varieties using a tailored package of practices – closer spacing, frequent pruning, controlled irrigation, and precise fertilizer application – all geared toward producing soft, succulent leaves throughout the year.

Why S36 and V1 are the preferred varieties 🔗

Among the dozens of mulberry cultivars available in India, S36 and V1 (Victoria-1) have established themselves as the top choices for chawki gardens in South India. Both were developed at the Central Sericultural Research and Training Institute (CSRTI), Mysore, and each brings distinct advantages.

S36 variety 🔗

S36 was evolved from Berhampore Local through chemical mutagenesis (EMS treatment) and was recommended for cultivation in 1984. It has a spreading branch pattern that creates a broad canopy, maximizing the leaf-producing surface area of each plant. The leaves are pale green, large, smooth, and glossy – exactly the kind of tender foliage young silkworms prefer. According to data from FAO’s documentation on Indian mulberry cultivation, S36 is particularly suited for young-age silkworm rearing.

V1 variety 🔗

V1, on the other hand, was developed from a cross between S-30 and Berc 776 and recommended in 1996 for assured irrigated conditions. Unlike S36, V1 grows with erect branches, making it suitable for areas where space is limited. Its leaves are dark green, large, thick, and have a high succulence level. V1 is known for very high sprouting ability, a rooting success rate exceeding 94%, and a higher photosynthetic rate and water-use efficiency compared to many other cultivars.

Both varieties respond well to the intensive management practices followed in chawki gardens – frequent irrigation, split fertilizer application, and short-interval harvesting.

Expected chawki leaf yield per hectare 🔗

When the recommended package of practices is followed consistently, a well-maintained chawki mulberry garden planted with S36 or V1 can produce 30 to 35 metric tonnes of chawki leaf per hectare per year. This figure is based on approximately 8 crop cycles per year, using a combination of individual leaf picking and shootlet harvesting methods.

Several factors influence whether you reach the upper or lower end of this range:

Soil health and fertilization: Chawki gardens need a strong nutrient base. The standard recommendation includes farmyard manure at 20 tonnes per hectare per year, supplemented with nitrogen, phosphorus, and potassium (NPK) in split doses aligned with each crop cycle. Nitrogen is especially critical because it directly influences the protein and moisture content of leaves.

Irrigation management: Regular irrigation at 7 to 10 day intervals is essential. Mulberry plants for chawki leaf production demand consistent soil moisture to produce the soft, succulent leaves that young worms need. Water stress causes leaves to become tough and nutritionally poor.

Pruning and harvest schedule: Chawki gardens are typically pruned at 25 cm above ground level. The short pruning height encourages dense shootlet formation, which in turn increases the volume of tender leaf available per harvest cycle. Harvesting at the right shoot age – generally around 30 to 45 days after pruning – ensures maximum leaf quality.

Pest and disease control: Mulberry is susceptible to several pests and diseases, including tukra (caused by mealy bugs), leaf roller, powdery mildew, and leaf spot. Integrated pest management (IPM) that combines biological control agents, resistant varieties, and targeted chemical application is critical for maintaining both leaf yield and quality.

Nutritional quality of chawki leaf from S36 and V1 🔗

Yield alone is not enough. The nutritional profile of the leaf matters just as much – arguably more – because poor-quality leaves fed to young silkworms lead to weak larvae, higher disease incidence, and poor cocoon output later on.

Here is a breakdown of the key quality parameters for chawki leaf from both varieties:

S36 chawki leaf quality 🔗

Moisture content: 78%. Nitrogen content: 3.75%. Crude protein: 23.43%. These values reflect leaves harvested under standard chawki garden management with recommended fertilizer and irrigation inputs.

V1 chawki leaf quality 🔗

Moisture content: 79%. Nitrogen content: 3.8%. Crude protein: 23.75%. V1 consistently records slightly higher values across all three parameters, which aligns with its overall reputation for superior leaf succulence.

Research published in biochemistry journals has confirmed that crude protein content in young mulberry leaves ranges from approximately 22% to 24% across popular varieties, with V1 being among the highest performers. The protein content tends to decline as leaves mature, which is exactly why chawki gardens harvest at a younger shoot age than late-age gardens.

Why these parameters matter 🔗

Moisture (78-79%): High moisture keeps leaves tender and easy for tiny first and second instar larvae to bite, chew, and digest. Leaves with moisture below 70% become too tough for young worms, leading to poor feeding and slower growth.

Nitrogen (3.75-3.8%): Nitrogen is a building block of amino acids and proteins. Higher nitrogen in the leaf translates to more protein available to the silkworm, which accelerates larval growth and strengthens the worm’s ability to resist diseases.

Crude protein (23.43-23.75%): Protein is the most critical nutrient for silkworms. During the chawki stage, rapid cellular growth and development require a protein-rich diet. Leaves with protein content below 20% typically result in weaker larvae and poorer cocoon outcomes.

Studies on the V1 variety have shown that foliar application of humic acid combined with fulvic acid can further boost leaf moisture content beyond 80% and increase protein levels, suggesting there is room to enhance quality even beyond the standard values.

Chawki silkworm rearing capacity per hectare 🔗

The ultimate measure of a chawki garden’s productivity is how many disease-free layings (dfls) it can support. With a yield of 30 to 35 metric tonnes of chawki leaf per hectare per year, the rearing capacity works out to approximately 1.66 to 1.94 lakh dfls per hectare per year. On a per-crop basis, this translates to roughly 20,000 to 24,000 dfls per crop cycle.

Each dfl contains approximately 500 larvae, so at the upper end, a single hectare of chawki garden can support the initial rearing of close to 97 million young silkworms annually – a staggering number that underscores the productivity of well-managed chawki gardens.

This capacity is directly tied to leaf quality. Higher moisture and protein levels mean the worms feed more efficiently, require less leaf per unit of growth, and complete the chawki stage faster with lower mortality. When worms from a properly managed chawki rearing operation move to the late-age rearing stage, they carry forward the health advantages gained during their early nutrition, resulting in better cocoon weight, shell ratio, and silk quality.

Cost economics of chawki leaf production 🔗

The cost of producing one kilogram of chawki leaf has been estimated at approximately Rs. 3 under standard management conditions. While this figure may vary based on regional input costs and labour rates, it reflects a relatively low per-unit cost given the high value that quality chawki leaves add to the entire sericulture chain.

Commercial Chawki Rearing Centres (CRCs) have become an increasingly popular model in Karnataka and other sericulture states. Research on the economic performance of CRCs has found that operations with larger chawki garden areas (6-7 acres) tend to achieve slightly better benefit-cost ratios than smaller units, though all sizes remain profitable. The selling price for chawki worms reared on quality leaf commands a premium because buyers know that healthy chawki worms translate to better cocoon harvests.

Practices that influence leaf quality beyond variety selection 🔗

While choosing S36 or V1 gives you a strong foundation, several agronomic practices further determine whether the leaf actually meets the target quality parameters.

Harvest timing 🔗

Leaves should be harvested in the early morning or late afternoon when moisture retention is naturally highest. Leaves picked during the midday heat lose moisture rapidly, making them less suitable for young worms.

Organic nutrition 🔗

The type of manure applied to the garden affects leaf biochemistry. Research has demonstrated that poultry manure applied to V1 mulberry produced leaves with significantly better moisture, carbohydrate, and protein levels compared to other organic inputs like cow dung or goat waste. Silkworms fed on these leaves showed higher moulting percentages and better overall rearing performance.

Soil pH management 🔗

Mulberry thrives in slightly acidic to neutral soils with a pH range of 6.2 to 6.8. Soils that are too alkaline or too acidic impair nutrient uptake, which directly reduces leaf quality. Regular soil testing and appropriate amendments – gypsum for alkaline soils and lime for acidic soils – are essential maintenance steps.

Weed and intercultivation management 🔗

Ploughing the garden after every pruning cycle removes weeds, improves soil aeration, and helps the soil absorb water and fertilizer more effectively. Intercultivation should be done both along and across mulberry rows for thorough weed control.

The link between chawki leaf quality and cocoon output 🔗

The connection between what a silkworm eats in its first two instars and the cocoon it produces weeks later is well established in sericulture science. Young silkworms fed with coarse or nutritionally inferior leaves become weak and susceptible to diseases like grasserie, flacherie, and muscardine in their later instars. Even if they survive to spin cocoons, the cocoons tend to be lighter with thinner silk shells.

Conversely, when chawki worms receive leaves with 78-79% moisture and 23-24% crude protein from a dedicated chawki garden, they develop stronger immune systems, moult cleanly, and transition to the late-age rearing stage in robust health. This foundation pays dividends throughout the rearing cycle – higher larval survival rates, heavier cocoons, better shell ratios, and ultimately, more and higher-quality raw silk per batch.

India’s sericulture extension systems across states like Karnataka, Tamil Nadu, and Assam emphasize chawki garden management as a non-negotiable best practice precisely for this reason. It is the single most impactful investment a sericulturist can make in their production system.

Key takeaways for sericulture farmers 🔗

Maintain a separate chawki garden – never rely on your late-age mulberry plot for young worm feeding. The quality requirements are fundamentally different.

Choose S36 or V1 – both deliver the high moisture, nitrogen, and protein levels that chawki worms need. V1 edges slightly ahead on all nutritional parameters and also offers higher yield potential (up to 40 MT/ha in some reports).

Follow the full package of practices – from soil preparation and fertilizer scheduling to irrigation, pruning, and pest management. Hitting the 30-35 MT/ha target requires discipline across every agronomic step.

Harvest at the right time and handle carefully – leaf quality deteriorates rapidly with improper handling or delayed transport to the rearing house.

Think of chawki leaf as an investment, not a cost – at roughly Rs. 3 per kilogram, chawki leaf is the most cost-effective input with the highest impact on final cocoon quality and revenue.

What do you think? Could better adoption of dedicated chawki mulberry gardens help India close the gap with countries like China in bivoltine silk production? And in your experience, does the choice between S36 and V1 make a noticeable difference in silkworm health during the chawki stage?

References

1. https://www.fao.org/4/x9895e/x9895e04.htm
2. https://www.researchgate.net/publication/341709641_Effect_of_Organic_Nutrition_In_Enhancing_Mulberry_And_Silkworm_Productivity-Review
3. https://www.sciencedirect.com/topics/engineering/mulberry-leaf
4. https://www.biochemjournal.com/archives/2026/vol10issue1S/PartI/S-10-1-197-207.pdf
5. https://www.biochemjournal.com/archives/2025/vol9issue8/PartK/9-8-69-173.pdf
6. https://www.agrifarming.in/silkworm-rearing-methods-beginners
7. https://www.extensionjournal.com/article/view/1254/7-10-47
8. https://sericulture.assam.gov.in/portlet-innerpage/rearing-of-mulberry-silkworm