Best Mulberry Varieties for Chawki Gardens: S36 and V1

In sericulture, the first few days of a silkworm’s life are the most critical. Young silkworms – called chawki worms – need soft, tender, nutrient-dense mulberry leaves to survive and grow. Feed them the wrong type of leaf and you risk poor growth, disease, and low cocoon yields. That’s exactly why chawki mulberry gardens exist: dedicated plots designed to produce leaves specifically suited for early-stage silkworm rearing. And when it comes to choosing the right variety for these gardens, two names consistently rise to the top – S36 and V1.

Why chawki gardens need special mulberry varieties 🔗

A chawki mulberry garden is not just any mulberry plot. It is a separate, purpose-built garden maintained exclusively to supply leaves for young silkworms during their first two instars (growth stages). The reason is straightforward: leaves from a general mulberry garden typically contain only about 68-70% moisture and have lower nutrient levels. Young silkworms, however, need leaves with much higher moisture, protein, and sugar content to support their rapid growth.

According to the IGNOU sericulture course material, the concept behind a chawki garden is to develop a continuous source of quality leaf that a general late-age garden simply cannot provide. Without this nutritional foundation, silkworms become susceptible to disease and produce inferior cocoons.

This is why variety selection matters so much. The mulberry variety planted in a chawki garden directly determines the moisture content, protein levels, sugar concentration, and overall digestibility of the leaves fed to young worms.

S36 mulberry variety: characteristics and performance 🔗

The S36 variety belongs to Morus indica and was developed at the Central Sericultural Research and Training Institute (CSRTI), Mysore. It was created through chemical mutagenesis of the Berhampore local variety and has been recommended for irrigated conditions in South India since 1984.

Growth habit and leaf features 🔗

S36 has a spreading branch type, meaning the branches grow outward and horizontally rather than upward. This creates a broad, open canopy that maximizes sunlight exposure across the foliage. The spreading habit also makes leaf harvesting easier for farmers, as leaves are accessible from multiple levels of the plant.

The leaves of S36 are large, pale green, entire (unlobed), smooth, and glossy. This smooth, glossy texture is an important quality indicator – it reflects the leaf’s succulence, which is exactly what young silkworms need. The pale green colour signals tenderness and high moisture retention.

Yield from chawki gardens 🔗

When grown specifically as a chawki garden, S36 produces approximately 30-35 metric tonnes of leaf per hectare per year. This is the yield of tender, young leaves suitable for chawki rearing – not the total leaf yield from a late-age garden, which can go higher (38-45 MT/ha/year) but includes more mature, coarser leaves.

Nutritional profile 🔗

The nutritional composition of S36 chawki leaves makes them well-suited for early-stage silkworm feeding. Based on data from IGNOU study materials and research reports, the chawki leaf of S36 contains approximately 78% leaf moisture, 3.75% nitrogen, and 23.43% crude protein. The high moisture content keeps the leaves soft and easy for tiny worms to consume and digest.

Disease tolerance 🔗

S36 shows tolerance to leaf spot and powdery mildew, two common mulberry diseases. However, it is moderately susceptible to leaf rust and tukra (caused by mealy bug infestation). One practical consideration is that S36 has only moderate rooting ability, so it is generally recommended to establish this variety using sapling plantation rather than direct cutting.

V1 mulberry variety: characteristics and performance 🔗

The V1 variety – officially named Victoria-1 – also belongs to Morus indica. It was developed at CSRTI, Mysore, from a cross between S-30 and Ber. C-776 and was recommended for cultivation in 1996. V1 quickly became one of the most popular mulberry varieties in South India, particularly in Karnataka’s irrigated sericulture belt.

Growth habit and leaf features 🔗

Unlike S36’s spreading pattern, V1 grows with erect branches that reach upward, creating a more compact and vertical plant structure. This upright growth habit makes V1 a good option where horizontal space is limited or where farmers prefer denser planting arrangements. The erect branching also allows better air circulation around the plant, which can help reduce fungal disease pressure.

V1 leaves are large, thick, succulent, entire, and ovate with a truncate base. They are smooth, glossy, and dark green in colour – a noticeable contrast to S36’s pale green leaves. The thickness and succulence of V1 leaves reflect their high water and nutrient content, making them particularly rich food for chawki worms.

Yield from chawki gardens 🔗

In a dedicated chawki garden setup, V1 yields around 30-40 metric tonnes of leaf per hectare per year. Under full irrigated conditions with recommended cultivation practices, V1’s total leaf production potential is even higher – up to 60-70 MT/ha/year when both young and mature leaves are counted. This makes V1 one of the highest-yielding mulberry varieties available in India.

Nutritional profile 🔗

V1 chawki leaves contain approximately 79% moisture, 3.8% nitrogen, and 23.75% crude protein. The moisture content in young leaves can reach as high as 78.9%, with a protein content of about 24.6% and total sugar content of around 16.98%. These numbers make V1 leaves highly nutritious – suitable not just for young silkworms but also for grown bivoltine silkworm rearing.

Disease tolerance and rooting 🔗

V1 is moderately resistant to leaf rust and tukra infestation, and shows resistance to leaf spot. Notably, the spread of tukra in V1 is lower compared to varieties like Kanva-2, S-13, S-34, and S-36, making it a relatively safer choice in tukra-prone areas. One major advantage of V1 is its very high rooting ability – over 94% – along with quick sprouting, high photosynthetic rate, and efficient water use. These traits make it easy to establish and maintain.

S36 vs V1: a side-by-side comparison 🔗

Both varieties excel in chawki gardens, but they differ in important ways. Here’s a quick comparison to help farmers choose:

Branch type: S36 has spreading branches; V1 has erect branches. Farmers with more horizontal space may prefer S36, while those with limited area might lean toward V1.

Leaf colour and texture: S36 produces pale green, smooth, glossy leaves. V1 produces dark green, thick, succulent leaves. Both are tender and suitable for young worms.

Chawki garden leaf yield: S36 gives 30-35 MT/ha/year, while V1 can reach 30-40 MT/ha/year – a slightly higher ceiling under optimal conditions.

Nutritional content: Both varieties have comparable moisture (78-79%), nitrogen (3.75-3.8%), and crude protein (23.43-23.75%). V1 has a marginal edge in protein and sugar content.

Rooting ability: S36 has moderate rooting ability (requiring sapling plantation), whereas V1 has very high rooting ability (>94%), making it easier and cheaper to establish.

Disease resistance: V1 shows better tolerance to tukra compared to S36. Both varieties handle leaf spot well.

Why moisture, sugar, and protein matter for chawki worms 🔗

Young silkworms are not simply smaller versions of older worms – their nutritional needs are fundamentally different. During the first two instars, chawki worms undergo extremely rapid growth and need leaves that are easy to eat, digest, and convert into body mass.

Moisture (76-80%): Chawki worms are tiny and cannot handle dry or tough leaves. High moisture content keeps leaves soft and prevents dehydration in the rearing bed. As noted in research on chawki rearing methods, maintaining proper bed humidity through succulent leaf is essential for silkworm health.

Protein (23-25%): Protein is the primary building block for silkworm growth. Crude protein levels of 23-25% in chawki leaves support the rapid cell division and tissue development that young worms need. Recent biochemical studies confirm that V1 and newer varieties like G4 consistently record superior protein content in young leaves compared to many other cultivars.

Sugar (11-16%): Sugars provide readily available energy. The total sugar content of 11-16% in S36 and V1 leaves ensures that young worms have enough energy for their active metabolism during the chawki stage.

Chawki rearing capacity from one hectare 🔗

A well-maintained chawki garden of S36 or V1 can support a significant scale of silkworm rearing. Based on available data, one hectare of chawki garden planted with these varieties can rear approximately 1.66 to 1.94 lakh disease-free layings (dfls) per year, or roughly 20,000-24,000 dfls per crop. This capacity depends on proper garden management – timely pruning, adequate irrigation, balanced fertilization, and correct leaf harvesting schedules.

The Karnataka State Sericulture Department recommends an annual pruning schedule of 4 prunings and 12 leaf harvests to maintain plant vigour and ensure a continuous supply of tender chawki leaves at 15-day intervals.

Establishing a chawki garden with S36 and V1 🔗

Setting up a chawki mulberry garden involves specific steps that differ from general mulberry cultivation.

Soil and site selection 🔗

Both S36 and V1 perform best in well-drained, fertile, loamy to clayey soils with a pH range of 6.2-6.8. The land should be flat and properly levelled. Before planting, apply 20 tonnes of well-decomposed farmyard manure (FYM) per hectare and incorporate it thoroughly into the soil.

Spacing and planting 🔗

For chawki gardens, closer spacing is often used to maximize the production of tender leaves. A common recommendation is paired row planting at (90 + 150) cm × 60 cm or standard 90 × 90 cm spacing. Since S36 has moderate rooting ability, it should ideally be planted using saplings. V1, with its high rooting ability, can be established using either cuttings or saplings.

Irrigation and fertilization 🔗

Regular irrigation at intervals of 7-10 days is essential, depending on soil type and weather conditions. The fertilizer schedule typically starts with a first dose of NPK at 50:50:50 kg/ha about three months after planting, followed by nitrogen top-ups after each leaf harvest. In established gardens, the recommended dose increases to support the high leaf production these varieties are capable of.

Leaf harvesting for chawki rearing 🔗

The key to getting high-quality chawki leaves is harvesting at the right time. Leaves should be picked when they are tender to medium maturity – typically from shoots that are younger than what would be used for late-age rearing. Harvesting in the early morning or late afternoon helps preserve maximum moisture content. Leaves should be handled gently to avoid bruising, which accelerates nutrient loss.

Other varieties worth knowing about 🔗

While S36 and V1 dominate chawki gardens in South India, a few other varieties deserve mention. G2, developed in 2003, is specifically recommended for exclusive chawki gardens and yields 36-38 MT/ha/year of chawki leaves. Kanva-2 is widely grown but has lower moisture content (about 70%) compared to S36 and V1, making it less ideal for young worms. For rainfed areas, S-13 and S-34 are better suited, though their leaf quality doesn’t match S36 or V1 under irrigated conditions.

In eastern and northeastern India, varieties like S-1635, S-1, and Tr-10 are preferred, as they are adapted to different climatic and soil conditions than those of the southern states.

The bottom line on choosing between S36 and V1 🔗

Both S36 and V1 are excellent choices for chawki gardens. If you’re in an area where tukra is a recurring problem, V1’s better tolerance gives it an edge. If ease of establishment is a priority, V1 wins again with its superior rooting ability. S36 remains a strong performer where spreading plant architecture is preferred and where its specific leaf texture suits local rearing practices.

The most important takeaway is this: investing in a dedicated chawki garden with either of these varieties – rather than relying on leaves from a general mulberry plot – is one of the most effective steps a sericulturist can take to improve silkworm health, cocoon quality, and overall silk production.

What do you think? If you had to choose between S36 and V1 for a new chawki garden, which factors would matter most to you – yield potential, ease of establishment, or disease resistance? And how do you think newer varieties like G2 and G4 might change the landscape of chawki garden cultivation in the coming years?

References

1. https://egyankosh.ac.in/bitstream/123456789/9102/1/Unit-3.pdf
2. https://www.fao.org/4/x9895e/x9895e04.htm
3. https://connectjournals.com/file_full_text/1792802H_657-665.pdf
4. https://www.biochemjournal.com/archives/2026/vol10issue1S/PartI/S-10-1-197-207.pdf
5. https://karunadu.karnataka.gov.in/Sericulture/english/Pages/Chawki-Rearing.aspx