Top Mulberry Varieties for Different Agro-Climatic Zones in South India

In sericulture, everything begins with the mulberry leaf. The variety of mulberry you plant determines how much leaf you harvest, how nutritious that leaf is for silkworms, and ultimately, the quality of silk you produce. Across South India – spanning Karnataka, Tamil Nadu, and Andhra Pradesh – mulberry cultivation covers about 90 percent of the country’s total mulberry area, making variety selection here a decision with enormous economic consequences. The difference between a well-chosen variety and a poorly matched one can mean a gap of 30-40 tonnes of leaf per hectare per year. Let’s look at which mulberry varieties perform best across South India’s diverse agro-climatic zones, and why each one matters.

Why mulberry variety selection matters in South India 🔗

South India’s sericulture belt stretches across tropical plains, semi-arid plateaus, and even hilly terrains. Each zone differs in rainfall, temperature, soil type, and irrigation access. A variety that thrives in Karnataka’s irrigated tracts may fail in a rainfed region of Andhra Pradesh. Picking the right cultivar ensures that your mulberry garden produces maximum leaf biomass with the best nutritional profile for silkworm rearing – which directly impacts cocoon weight, shell ratio, and raw silk quality.

According to data from the Central Sericultural Research and Training Institute (CSRTI), Mysore, recommended varieties for South India fall into two main groups: those suited for irrigated conditions (Kanva-2, S-36, S-54, V-1, DD, and MR-2) and those bred for rainfed conditions (Kanva-2, S-13, and S-34). Each has distinct strengths.

High-yielding varieties for irrigated regions 🔗

Where assured irrigation is available, farmers can take advantage of varieties that respond aggressively to water and fertilizer inputs. These cultivars produce significantly more leaf biomass per unit area and support higher silkworm rearing densities.

V-1 (Victory-1): the top performer 🔗

V-1 is widely regarded as the most productive mulberry variety in South India today. It was developed at CSRTI, Mysore, from a cross between S-30 and Berc-776, and was recommended for irrigated conditions in South Indian states. Under assured irrigation with recommended agronomic practices, V-1 can yield approximately 60-70 tonnes of leaf per hectare per year – nearly double what older varieties produce.

What makes V-1 stand out is a combination of traits. It has very high sprouting and rooting ability, making establishment easier. Its leaves are dark green, succulent, unlobed, and have a high moisture content of around 78 percent, which keeps them fresh longer in silkworm rearing beds. The variety develops multiple productive branches and maintains a high leaf-to-stem ratio throughout the harvesting season. Because of its large biomass production, wider plant spacing is recommended for V-1 compared to other varieties. V-1 is also considered relatively tolerant to tukra disease caused by mealybug infestation, giving it an edge in pest management.

V-1 performs especially well in Karnataka’s irrigated mulberry regions and has become the preferred choice for farmers aiming to maximize both leaf output and silkworm productivity.

S-36: balancing yield and quality 🔗

S-36 was developed at CSRTI through chemical mutagenesis (EMS treatment) of the Berhampore Local variety and was recommended for cultivation in 1984. It belongs to Morus indica and is suited for irrigated conditions across South India. Under good management, S-36 yields about 38-45 tonnes of leaf per hectare per year.

S-36 produces pale green, smooth, unlobed, ovate leaves with a coriaceous (leathery) texture. Its leaf quality characteristics – including a good balance of moisture, protein, and sugar – make it a reliable choice for consistent silkworm feeding. The variety is highly responsive to agronomic inputs, meaning that farmers who invest in proper fertilization and irrigation schedules see strong returns. S-36 is also recommended for silkworm seed crop production, alongside the Viswa variety.

Kanva-2 (M-5): the dependable all-rounder 🔗

Kanva-2, also known as M-5 or Mysore-5, is one of South India’s oldest improved varieties. It is an open-pollinated hybrid selection from the seedling population of the Mysore Local variety, selected at the Kanva Silk Farm near Channapatna. CSRTI recommended it for cultivation in 1969.

Under irrigated conditions, Kanva-2 yields about 30-35 tonnes of leaf per hectare per year. Its leaves have a moisture content of around 70 percent, a protein content of 21 percent, and a sugar content of 11.5 percent. It has high rooting ability (about 80 percent) and adapts well to a wide range of growing conditions. Kanva-2 is resistant to leaf spot and moderately resistant to leaf rust and powdery mildew. While it doesn’t match V-1 or S-36 in raw yield, its wide adaptability and reliability make it a dependable choice, particularly for farmers who are new to sericulture or working in areas with variable conditions.

Viswa (DD): suited for hot and arid zones 🔗

The Viswa variety – also referred to as DD – was selected from the natural population of the Dehra Dun area and released by the Karnataka State Sericulture Research and Development Institute (KSSRDI). It has been authorized by the Mulberry Variety Authorization Committee for cultivation in irrigated, high-temperature, and hot-arid regions of South India.

Viswa has good sprouting and rooting ability with fast growth, making it suitable for 5-6 harvests per year. It yields approximately 40-45 tonnes of leaf per hectare per year under irrigated conditions. The variety performs well in closer spacing (60×60 cm or 60×90 cm) and is a practical option for farmers in drier inland areas where heat tolerance is critical.

Varieties for rainfed conditions 🔗

A large portion of South India’s mulberry cultivation depends entirely on monsoon rainfall. In areas receiving 500-800 mm of annual rainfall, water stress is common, and only specifically adapted varieties can sustain productive leaf output. The FAO recommends Kanva-2, S-13, and S-34 for these rainfed zones across Karnataka, Andhra Pradesh, and Tamil Nadu.

S-13: resilient on red loamy soils 🔗

S-13 is a selection from open-pollinated hybrids of Kanva-2, recommended for rainfed areas of South India since 1990. It belongs to Morus indica and is characterized by short internodes and a capacity to produce a large number of branches, which helps compensate for the reduced growth rate under water-limited conditions.

Under rainfed conditions, S-13 yields about 12-15 tonnes of leaf per hectare per year. It has a high protein content of about 24.3 percent and a sugar content of 13.8 percent, which means the nutritional quality of its leaves remains strong even under stress. S-13 is resistant to leaf spot and powdery mildew, and moderately resistant to leaf rust. It is specifically recommended for rainfed areas with red loamy soils and water-scarce zones of Andhra Pradesh.

S-34: built for black cotton soils 🔗

S-34 was developed from a cross between S-30 and Berc-776 and recommended in 1990 for rainfed areas with black cotton soils. It has a fast growth habit and a deep, extensive root system that allows it to access moisture from lower soil layers during dry spells.

This variety produces medium to large, unlobed, dark green leaves with good moisture retention. Under rainfed conditions, it yields about 15 tonnes of leaf per hectare per year. With a crude protein content of 23.7 percent and sugar content of 13.2 percent, S-34 provides high-quality nutrition for silkworms even in challenging growing environments. It is resistant to powdery mildew and leaf rust, though it shows some susceptibility to tukra infestation. S-34 and S-13 together cover the two dominant rainfed soil types in South India – black cotton soil and red loamy soil, respectively.

Kanva-2 under rainfed conditions 🔗

Kanva-2 serves a dual role – it works under both irrigated and rainfed systems, though with very different yield outcomes. Under rainfed conditions, its yield drops to about 10-12 tonnes per hectare per year, significantly lower than S-13 or S-34. However, its wide adaptability and familiarity among farmers keep it in use in many rainfed zones, especially where growers are cautious about adopting newer varieties.

MR-2: the Tamil Nadu specialist 🔗

MR-2 (Mildew Resistant-2) holds a special place in Tamil Nadu’s sericulture landscape. It was developed by the Tamil Nadu Sericulture Department at their experimental station in Coonoor during the 1970s. It belongs to Morus sinensis and was specifically bred for resistance to powdery mildew disease caused by Phyllactinia corylea.

MR-2 yields approximately 25-35 tonnes of leaf per hectare per year under irrigated conditions in Tamil Nadu. Its leaves have a protein content of 23.2 percent and moisture content of about 68 percent. What makes MR-2 particularly valuable is its dual suitability – it performs well in the irrigated plains of Tamil Nadu and also adapts to rainfed conditions in hilly regions. However, the variety is susceptible to thrips attack, which requires careful pest monitoring during certain seasons. Despite this limitation, MR-2 remains a cornerstone of Tamil Nadu’s sericulture industry, trusted by thousands of farming families across the state.

Comparing leaf yield across varieties 🔗

To put the performance differences in perspective, here’s a quick comparison of approximate annual leaf yields under their recommended conditions:

Under irrigated conditions: V-1 leads at 60-70 tonnes/ha/year, followed by S-54 at around 45 tonnes, Viswa (DD) at 40-45 tonnes, S-36 at 38-45 tonnes, Kanva-2 at 30-35 tonnes, and MR-2 at 25-35 tonnes (Tamil Nadu-specific).

Under rainfed conditions: S-34 yields about 15 tonnes/ha/year, S-13 about 12-15 tonnes, and Kanva-2 about 10-12 tonnes.

The yield gap between irrigated and rainfed conditions is striking – V-1 under irrigation can produce four to five times more leaf than Kanva-2 under rainfed management. This gap underlines why irrigation access is the single most important factor in variety selection and overall sericulture profitability.

Factors beyond variety: getting the most from your choice 🔗

Selecting the right variety is the foundation, but management practices determine whether you actually achieve the variety’s yield potential. Several factors play a critical role:

Spacing: High-yielding varieties like V-1, which produce large biomass, benefit from wider spacing. A standard spacing of 90×90 cm works well for most varieties, while some systems use paired-row planting (150 cm + 90 cm × 60 cm) to improve light penetration and air circulation.

Fertilization: Improved varieties are highly responsive to nutrient inputs. The recommended dose for mature irrigated mulberry gardens is typically 350:140:140 kg/ha/year of N:P:K, applied in split doses. Organic manure (farmyard manure at 20 tonnes/ha) should be incorporated as a basal application. The KSSRDI has developed nutrient budgeting protocols for different mulberry genotypes and recommends biofertilizers like Azotobacter and VAM for cost-effective nutrient supplementation.

Harvesting method: For irrigated high-yielding varieties, shoot harvesting (cutting entire branches) is more efficient and is commonly used for the shoot-rearing method of silkworm feeding. For rainfed varieties with lower biomass, individual leaf harvesting is preferred to avoid stressing the plant.

Pest and disease management: Each variety has a different disease resistance profile. V-1 is relatively tolerant to tukra, MR-2 resists powdery mildew, and S-13 resists leaf spot. Knowing your variety’s vulnerabilities helps you plan targeted pest management rather than broad-spectrum interventions.

Newer varieties on the horizon 🔗

Breeding efforts continue at institutions like CSRTI Mysore and KSSRDI. Newer varieties such as G-2, developed from a cross between M. multicaulis and S-34, is specifically designed for chawki (young silkworm) garden use, yielding 36-38 tonnes/ha/year of leaves particularly suited for early-instar silkworms. Another variety, G-4, has shown promising results in nursery trials, with improved pest resistance and vigorous sapling growth. The KSSRDI also maintains a germplasm bank of 380 mulberry accessions from 27 countries, which serves as the genetic resource base for future breeding programs. Varieties like Suvarna-1, Suvarna-2, and Vishala are also being evaluated for specific agro-climatic niches.

Matching variety to your specific zone 🔗

Here is a practical guide for choosing your variety based on location and conditions:

Karnataka (irrigated tracts): V-1 is the top recommendation, followed by S-36 and Viswa. For silkworm seed crop gardens, S-36 and Viswa are preferred.

Karnataka (rainfed, red loamy soils): S-13 is the primary choice, with Kanva-2 as an alternative.

Karnataka (rainfed, black cotton soils): S-34 is specifically recommended for this soil type.

Tamil Nadu (irrigated plains): MR-2 is the local favourite due to its powdery mildew resistance. V-1 and S-36 are also used where management inputs support their higher demands.

Andhra Pradesh (irrigated): V-1 and S-36 perform well. For water-scarce zones, S-13 is the go-to option.

Hot-arid regions: Viswa (DD) has been specifically authorized for high-temperature and hot-arid conditions.

Hilly regions of South India: MR-2 adapts well to higher-altitude conditions in Tamil Nadu’s hill zones.

What do you think? If you’re planning a new mulberry garden, how would the irrigation availability in your area influence your variety choice? And for those already growing mulberry – have you noticed measurable differences in silkworm health and cocoon quality when switching between varieties?

References

1. https://www.fao.org/4/x9895e/x9895e04.htm
2. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0252246
3. https://silks.csb.gov.in/pakur/wp-content/themes/Common_District/pakur/ivs-frame.html
4. https://kssrdi.karnataka.gov.in/info-1/Research+Divisions/en
5. https://kssrdi.karnataka.gov.in/page/Contributions/Moriculture%20Technologies/Mulberry+Breeding+and+Genetics/en
6. https://dacollege.org/uploads/stdmat/seri-SEM2-unit-1-and-4.pdf