Sericulture Industry in India – A Review

 

 

D. Gangopadhyay

 

The reduction of rural poverty continues to be a paramount goal of the developing countries like India as the majority of the poor population still resides in the countryside. The World Bank, for example, estimates that more than 70 % of the world’s poor live in rural areas. So far, various strategies have been pursued to address this concern and among the major ones is rural employment creation. The agriculture sector, however, has been contending with a number of factors that have limited its potential for generating new jobs in rural areas. Those factors may include the small land holding size, insufficient capital and investment incentives, the inadequate farm infrastructure, limited market and stagnant prices of agricultural products. It is therefore necessary to focus on a broader spectrum of the rural economy. The establishment of rural based industries like sericulture, in particular, can be very effective in creating new job opportunities and providing supplemental income. Being a rural agro-based labour intensive industry this sector can also play vibrant role in checking migration from rural to urban areas. In this article, the present status of the sericulture industry in India, its trends, position in global sericulture and science and technological achievements have been reviewed. Besides, some  critical issues like potentiality of the sector in national economy, rural development, women empowerment and employment generation have been identified. An attempt has been made to draw a strategic model to strengthen and promote sericulture industry in India to enhance productivity and quality of silk etc. This article would be helpful in recognizing the potential, strength and challenges of the sericulture industry in India so as to formulate certain policies and measures for socio-economic development.

 

 

Introduction 

Sericulture is both an art and science of raising silkworms for silk production. Silk as a weavable fiber was first discovered by the Chinese empress Xi Ling Shi during 2,640 B.C. and its culture and weaving was a guarded secret for more than 2,500 years by the Chinese. Silk was a profitable trade commodity in China. Traders from ancient Persia (now, Iran) used to bring richly coloured and fine textured silks from Chinese merchants through hazardous routes interspersed with dangerous mountainous terrains, difficult passes, dry deserts and thick forests. Though, commodities like amber, glass, spices and tea were also traded along with silk which indeed rapidly became one of the principal elements of the Chinese economy and hence, the trade route got the name ‘SILK ROUTE’. Even today, silk reigns supreme as an object of desire and fabric of high fashion. Being a rural based industry, the production and weaving of silk are largely carried out by relatively poor sections of the society and this aspect of sericulture has made it popular and sustainable in countries like China and India.

 

Sericulture Industry in India

If fashion is a fine art, then silk is its biggest canvas, and if silk is the canvas, then all its weavers, dyers, designers, embroiderers are the greatest artists. Indian silk has enthralled fashion watchers and all categories of consumers across the world with its vast repertoire of motifs, techniques and brilliant hues. India’s traditional and culture bound domestic market and an amazing diversity of silk garments that reflect ‘geographic specificity’ has helped the country to achieve a leading position in silk industry.

Present status: India is the second largest producer of raw silk after China and the biggest consumer of raw silk and silk fabrics. An analysis of trends in international silk production suggests that sericulture has better prospects for growth in the developing countries rather than in the advanced countries. Silk production in temperate countries like Japan, South Korea, USSR etc., is declining steadily not only because of the high cost of labour and heavy industrialization in these countries, but also due to climatic restrictions imposed on mulberry leaf availability that allows only two cocoon crops per annum. Thus, India has a distinct advantage of practicing sericulture all through the year, yielding a stream of about 4 – 6 crops as a result of its tropical climate.

In India, sericulture is not only a tradition but also a living culture. It is a farm-based, labour intensive and commercially attractive economic activity falling under the cottage and small-scale sector. It particularly suits rural-based farmers, entrepreneurs and artisans, as it requires low investment but, with potential for relatively higher returns. It provides income and employment to the rural poor especially farmers with small land-holdings and the marginalized and weaker sections of the society. Several socio-economic studies have affirmed that the benefit-cost ratio in sericulture is highest among comparable agricultural crops (Table 1).

 

 

Table1: Cost:Benefit analysis of mulberry sericulture and other competing crops.

Item

Mulberry sericulture

Sugarcane

Turmeric

Total input costs

48,659

30,575

29,610

Gross returns

96,132

60,200

55,317

Net returns

47,476

29,625

25,707

CB ratio

1:1.98

1:1.97

1:1.02

Crop period

1 year

1 year

4 – 5 months

Note: Data in Rs/acre/annum

Source: Dandin et al., presented at the 20th Conference of the International Sericulture Commission, Bangalore, December, 2005

 

 

Currently, the domestic demand for silk, considering all varieties, is nearly 25,000 MTs, of which only around 18,475 MTs (2006-07) is getting produced in the country and the rest being imported mainly from China. Indian domestic silk market has over the years been basically driven by multivoltine mulberry silk. Due to inferior quality of the silk produced, India could not meet the international quality standard. Though, R&D efforts have been made to improve the quality of multivoltine silk, even the best of multivoltine silk produced could not match the bivoltine silk in quality. Therefore, it is essential to enlarge the production base and improve current productivity levels of bivoltine silk to meet the international standards and quality demands of the power loom sector. Steps need to be taken to ensure that export oriented units having automatic state of the art weaving machinery. 

  

Types of silks in India:   India is a home to a vast variety of silk secreting fauna which also includes an amazing diversity of silk moths. This has enabled India to achieve the unique distinction of being a producer of all the five commercially traded varieties of natural silks namely, Mulberry, Tropical Tasar, Oak Tasar, Eri and Muga. Silk obtained from sources other than mulberry are generally termed as non-mulberry or Vanya silks. The bulk of the commercial silk produced in the world is mulberry silk that comes from the domesticated silkworm, Bombyx mori L. which feeds solely on the leaves of the mulberry (Morus sp.) plant. Tasar silk is copperish in colour, coarse in nature and is mainly used for furnishing and interiors and secreted by the Tropical Tasar silkworm, Antheraea mylitta which thrives on Asan and Arjun (Terminalia sp.). Rearing is done on naturally growing trees in the forests and is the main stay for many tribal communities in the states of Jharkhand, Chhattisgarh, Orissa, Maharashtra, West Bengal and Andhra Pradesh. Oak Tasar is a finer variety of Tasar produced by the temperate Tasar silkworm, Antheraea proylei which feeds on natural oak plants (Quercus sp.) and is found in abundance in the sub-Himalayan belt. Eri silk is a silk spun from open-ended cocoons and secreted by the domesticated silkworm, Samia cynthia ricini that feeds mainly on castor leaves. Muga silk is golden yellow in colour and an exclusive produce of India, primarily the state of Assam where it is the preferred attire during festivities. Muga silk is secreted by Antheraea assama that feeds on aromatic leaves of naturally growing Som (Persia bombycina) and Sualu (Litsea polyantha) plants. Variety-wise share of raw silk production during the year 2007-08 has been depicted in Figure 1.

 

 

Fig 1: Variety-wise raw silk production (2007-08)

Source: Indian Silk 47(5), 2008

 

 

Trends in Indian sericulture:   Over the last six decades Indian silk industry has registered an impressive growth, both horizontally and vertically. Plans and schemes implemented by central and state agencies and relentless efforts of thousands of dedicated persons in the fields of research and extension have helped in this context. For instance, the age old multivoltine hybrids have been replaced by multivoltine × bivoltine and bivoltine hybrids. The sericulture industry has witnessed a quantum jump in raw silk productivity. The average yield of 25 kgs of cocoons/100 dfls in the recent past has increased and currently the average yields are in the range of 60 – 65 kgs/100 dfls. The new technology, besides doubling yields has also led to qualitative improvements in cocoon production with considerably reduced renditta and has also helped break the climate barrier. Silk statistics of India is presented in Table 2.

 

 

Table 2: Silk statistics of India

Particulars

Unit

Year

2002-03

2003-04

2004-05

2005-06

2006-07

Production of silk (Total)

MT

16319

15742

16500

17305

18475

Mulberry

MT

14617

13970

14620

15445

16525

Tasar

MT

284

315

322

308

350

Eri

MT

1316

1352

1448

1442

1485

Muga

MT

102

105

110

110

115

Production of silk fabrics

Rs./Crore

8280

8201

8870

9812

9240

Silk Imports

Rs./Crore

647

628

607

780

673

Mulberry acreage

Ha.

194463

185120

171959

179065

191183

Source: DGCIS, Ministry of Commerce, Govt. of India.

 

 

The market share of Indian silk exports in the global silk trade is 4 – 5 % which is not significant considering the fact that India is the second largest producer of raw silk. This is because India has a large domestic market for silk goods and about 85 % of silk goods produced are sold in the domestic market. However, India exports approximately 15 % of its output of all types of silk goods (including value-added items). The export of Indian silk products consists of finished goods like fabrics, made-ups, ready-made garments and furnishing materials like curtains, carpets, bed spreads, cushion covers etc. The export of silk products has been showing a steady growth and the export earnings showed a rapid increase during the last decade (Figure 2). 

 

 

 

Fig 2: Year-wise silk export earnings

Source:   DGCIS, Ministry of Commerce, GoI

 

 

Indian position in global sericulture:  The global raw silk production was around 1,25,605 MTs in the year 2005-06, with China as the major player with 81.65 % share  followed by India with around 14 % (Table 3). Though, Indian breeds/hybrids have the potential to produce the same quality, our system of sericulture practices is entirely different from those of the Chinese. The strict maintenance of discipline and better linkage from farmers to weavers, large-scale operation of egg production, reeling and weaving using modern machineries, strict control measures for diseases, uniform adoption of new technologies, supply of required quantity of quality eggs in time to avoid the chances of contamination of young silkworm etc. make the Chinese sericulture more vibrant, economically sound and sustainable. Another area of difference is that the entire production is state controlled with no open marketing/auction systems for silk cocoons and yarns. The comparative statistics (Table 4) indicate the strength of China in the areas of seed production and distribution system, higher unit area productivity and quality thus reducing the costs of production.

 

 

Table 3: World raw silk production

 

2000

2001

2002

2003

2004

China

61648

64567

68600

94600

102560

India

15857

17351

16319

15742

16500

Japan

557

431

394

287

263

S. Korea

165

157

154

150

150

Brazil

1389

1485

1607

1563

1512

Uzbekistan

1100

1260

1260

950

950

Thailand

955

1510

1510

1500

1420

Vietnam

780

2035

2200

750

750

Others

1952

1692

3814

1500

1500

Total

84403

90488

95858

117042

125605

Note:  Unit in Metric tons

Source: Sericulture and silk statistics, 2003, Silk industry at a glance (2005-06), Central Silk Board, Bangalore and Sericologia, Vol. 44 (3), 2004.

 

 

Table 4:  Comparative mulberry sericulture statistics- China vis-à-vis India

Parameter

China*

India

Area under mulberry (lakd ha.)

7.36

1.79

Leaf yield (MTs/ha/yr)

25-30

30-50

Races reared

All bivoltine

Mostly cross breeds

Egg production (crore dfls)

75.962

25.65

Supply syste,

Majority chawki reared

Majority supplied as eggs

Time of supply

Batch-wise

Throughout the year

No. of crops per yea

2-3: Temperate

6-8: Tropical

5-6

8-12 (Split plot system)

Dfls brushed / ha / yr

1050

1492

Cocoon yield (kg / 100 dfls) (2 boxes)

75.92

51.0

Leaf cocoon raio (kg)

16-18

20-22

Cocoon yield (kg / ha)

736.89

698.0

Cocoon weight (g)

1.9-2.0

1.6-1.8

Cocoon shell percentage (%)

21-23

CB: 17-19

BV: 20-22

Filament length (m)

>1000

<1000

Renditta

6.4

8.2 (6.9 for bivoltine)

Grade of silk

A – 4A

Un-graded to A grade

Cost of cocoon production (Rs. / kg)

40-45

65-70

Prevailing cocoon price (Rs)

85-90

90-120

Raw silk production (kg/ha/yr)

114.87

85.02

Av. Crop loss / year (%)

3-5

10-15

Demand and supply position

90% Export

Self consumption 30 % deficit

Raw silk produced (MTs / yr)

86500

15445

Source: *Li Long and Hu Zhuozhong, Indian Silk, May 2006.

 

 

Science, Technology and Sericulture

Science and technology is used as an effective instrument of growth and change. It is being brought into the mainstream of economic planning in the sectors of agriculture, industry and services. The country's resources are used to derive the maximum output for the benefit of society and improvement in the quality of life. About 85 % of the funds for S&T come directly or indirectly from the Government. Central Silk Board (CSB), Bangalore under the Ministry of Textiles, Govt. of India is the apex body for overall development of sericulture and silk industry in India. The functions assigned to the Board are to promote development of the silk industry by all appropriate measures like undertaking, assisting and encouraging scientific, technological and economic research, improvement of mulberry cultivation, production and distribution of healthy silkworm seed, production of quality raw silk and promotion of silk market etc. In addition, the board is responsible for advising and reporting to the Govt. of India on all matters relating to the development of the raw silk industry, including the import and export of raw silk. Indian sericulture is not only vast, widely dispersed but also multidisciplinary in nature involving silkworm seed sector, cocoon sector (cultivation of food plants and silkworm rearing) and post cocoon sector (silk reeling, spinning, twisting, processing and weaving). Therefore, Central Silk Board, recently, is coordinating and implementing collaborative research activities in association with National level R&D Institutions, State Sericulture Research and Development Institutes, Universities, Department of Science and Technology, Department of Biotechnology, CSIR/ICAR/IARI/IITs/IIMs and other Private and International Research and Development Institutions to promote applied research and development of appropriate technology towards attaining higher quality and productivity levels of Indian silk. R&D achievements of CSB like technologies patented and commercialized are given in Table 5 and discussed below:

 

 

Table 5: Technologies patented during 1997-2002 by Central Silk Board

S. No.

Technology/Product

Patent No.

Innovator

1.

Machine for crushing shoots

PAT/4.3.3.1/96039

CSRTI, Mysore

2.

Cocoon De-flossing Machine

PAT/4.3.3.2/96040

CSRTI, Mysore

3.

Machine for preparation of cutting

PAT/4.3.3.3/96041

CSRTI, Mysore

4.

Denier Detecting Device in Silk Reeling

PAT/4.4.4.1/96076

CSTRI, Bangalore

5.

Reel Permeation Chamber-Hand-Operated

PAT/4.4.19.2/96085

CSTRI, Bangalore

6.

Pedal Operated Reeling Cum Twisting Machine for

Muga and Tasar Silk Reeling

PAT/4.4.19.1/96089

CSTRI, Bangalore

7.

Long Skein Silk Book Making Machine

PAT/4.4.12.1/96097

CSTRI, Bangalore

8.

Composition and Process for Softening of Water

PAT/4.4.23.1/96098

CSTRI, Bangalore

9.

Multi-fuel Economic Oven Machine

PAT/4.4.13.1/96099

CSTRI, Bangalore

10.

An oven and adopted to used for Reeling of silk yarn

PAT/4.4.5.1/96100

CSTRI, Bangalore

11

A process for preparation of trap – Uzi trap

PAT/4.4.21.1/96103

CSRTI, Mysore

12

Bed Disinfectant for Silkworm – RKO

PAT/4.4.18/96150

CSRTI, Mysore

13

Vijetha – a Bed Disinfectant

PAT/4.4.22.1/96151

CSRTI, Mysore

14

Bio-fungicide

PAT/4.4.18.2/96152

CSRTI, Mysore

15

A Process for preparation of TRID – NUTRID

PAT/4.4.14.1/96153

CSRTI, Mysore

16

A Process for prep. of Phytosone extracted from plant material

PAT/4.4.16.1/96154

CSRTI, Mysore

17

Grainage Tray

PAT/4.3.20.1/98100

CTRTI, Ranchi

18

Nursery Technique for Raising T. arjuna seedling

PAT/4.3.14.1/98103

CTRTI, Ranchi

19

Machine for pruning of Mulberry plant

PAT/4.4.13.1/99015

CSRTI, Mysore

20

Fly – Trap

PAT/4.3.6./99033

CSRTI,Ber’pore

21

Raksha Rekha Trademark Registration

PAT/4.3.20/99038

CSRTI, Mysore

22

Low Cost Environator

PAT/4.3.12/99049

CSRTI, Mysore

23

Silkworm Egg Box

PAT/4.3.19/99062

CSRTI,Ber’pore

24

Light Weight Rearing Tray

PAT/4.3.121/99073

CSRTI,Ber’pore

25

Resham Jyoti Trademark Registration

PAT/4.19.20/99130

SSTL, Kodathi

26

Labex

-

CSRTI,Ber’pore

27

Tasar Chawki Nylon Net

-

CTRTI, Ranchi

28

Integrated Package for rearing tasar silkworm

-

CTRTI, Ranchi

29

Phyllanica for uniform and advanced maturity in silkworm

-

CSRTI,Ber’pore

Source: Central Silk Board R & D achievements during the IXth plan period.

 

 

 

 

Mulberry Improvement

  1. High yielding mulberry varieties    like V-1 (leaf yield-70MT/ha/yr), G-4 (9% more than V-1); G-2 and G-5 (20% - 30% more than existing S36 i.e., 45MT/ha/yr).
  2. Moisture stress rainfed improved mulberry varieties  like AR-10 and AR-11 (15-20 % more yield than existing S-13 i.e., 10-12MT/ha/yr), C-1730 (leaf yield-13.3 MT/ha/yr and suitable to red lateratic soil of West Bengal)
  3. Alkaline and saline tolerant improved mulberry varieties   like AR-12 and AR-14 (alkaline tolerant; 15-20% more yield than existing S-34), C776 (saline tolerant with yield potential 37/MT/ha/yr suitable for West Bengal).
  4. Water stress triploid mulberry variety  like S-1635 during rainy season in high rainfall areas of West Bengal and Assam. It has a potential to yield 6225 kg/ha/crop.
  5. Shade tolerant mulberry variety   like K2 x Kosen for cultivation under mulberry-coconut tree intercropping with potential yield of around 44 MT/ha/yr.
  6. Low fertilizer input and better yield mulberry varieties   like RC1 and RC2 (low fertilizer inputs i.e., 50% fertilizers and 40 % irrigation and 10 – 20 % more leaf yield than V1 variety).
  7. Low cost tender mulberry shoot propagation  using dried sugarcane leaf in place of white polythene sheet as cover. Under the “Development of economically viable module of mulberry plantation” intercropping with Lentil recorded a maximum yield with a return of Rs. 10,800/crop.

 

Mulberry Productivity

  1. Paired row system [(90 +150) x 60 cm] of mulberry propagation   with 350:140:140 Kg NPK/ha/yr and 20 MT/ha of FYM under irrigated condition for higher leaf productivity and improvement in leaf quality.
  2. Moisture conservation technique of mulberry propagation   with 90 x 90 cm spacing and NPK @ 100:50:50 Kg/ha/yr for improved the leaf quality and higher yield. Evaluation of micro-jet system recorded an optimum yield of 64 MT/ha/yr, followed by micro-tubing systems (63 MT/ha/yr) like PC Dripper and in-line system of drip irrigation to save 40% irrigation water.
  3. Package of practices for the cultivation of mulberry in alkaline soils   like 90 x 90 cm plant spacing, application of 40 MT press mud and fertilizer at 250:120:90 kg NPK/ha/yr.
  4. ‘In-situ’ vermi-compost   supplemented with 50% recommended dose of NPK fertilizer to improve soil organic carbon content without affecting leaf yield and leaf quality.
  5. Application of phosphate solubilizing bacteria (Bacillus megatherium)  along with rock phosphate to mulberry garden to increase leaf yield by 1.8 MT/ha/yr with a net saving of Rs. 1745/ha/yr towards phosphate fertilizer cost.
  6. Application of Azotobacter biofertilizer    supplemented with 50% nitrogenous fertilizer along with foliar application of n-Triacontanol twice @ 125 ml/ 600 lt. water. The leaf productivity remained on par with full dose application of nitrogen fertilizer application. The cost benefit ratio of 1:1.98 indicates the positive response of the technology. Over 32 thousand farmers recorded an average increase in leaf yield by 15-20 %.
  7. Seri-boost’- Triacontanol based micronutrient formulation  for spaying (@ 2.5 ml/l water twice per crop) to enhance leaf yield by 10-15%. Inoculation of Vesicular - Arbuscular Mycorrhiza (VAM) fungi to mulberry roots to help supplementation of phosphate fertilizers by 75%. Spraying of plant growth regulators like Maleic hydrazide (MH) and 2 - Chloroethyl trimethyl ammonium chloride @ 5 to 100 ppm to improve leaf yield by 2-10% marginally.

 

Mulberry Protection

  1. ‘Raksha’ (Trichoderma harzianum) to control the root rot disease.
  2. Nursery-Guard’ (Trichoderma pseudokoningii) to prevent nursery disease.
  3. ‘Bionema’ (Verticillium chlamydosporium) to reduce root knot disease.
  4. Neem formulation to suppress leaf roller infestation.
  5. Acaciacide (an eco-friendly bio-nematicide) to reduce root gall and incidence of tukra disease.
  6. Ethanolic extracts of Eucalyptus to supressMyrothecium leaf spot disease.
  7. Aqueous ethanolic extracts of two Cassia species to reduce powdery mildew disease.
  8. Eco-friendly technology involving a bio-nematicide and neem oil cake for the control of root knot nematode disease results to increase leaf yield and additional income of Rs. 7300/ha/yr.
  9. Growth promoting bacteriaAzotobacter chroococcum’, ‘Bacillus megaterium’ and ‘Pseudomonas fluorescens’  toinduce systemic resistance in mulberry against leaf spot and leaf rust diseases.

 

Integrated Pest Management and Disease Control

  1. Cost-effective integrated package comprising of biological agents (Cryptolaemus montrouzierie), mechanical removal of affected parts and chemical measures (0.2 % DDVP) for effective management of mealy bug causing tukra – a serious disease results in a leaf yield loss up to 30 %. Adoption of IPM in three southern sericulture states, covering 1105 ha of mulberry plantation led to 67% pest suppression and 62% disease loss.
  2. IPM for management of Leaf roller (Diaphania pulverulentalis)   includes spraying of DDVP and release of egg parasitoids Trichogramma chilonis and pupal parasitoid Trichogramma howardii.
  3. IPM for management of Whitefly (Bemisia spp)   includes use of chemical pesticides and botanicals like 0.05% Acephate, 0.05% Monocrotophos, 1% Rakshak and 0.1% Dichlorvos as well as release of natural predators of whitefly viz., Brumoides suturalis, Micraspis discolor, Micraspis crocea and Serengium persesstosum to reduce pest population below economic threshold Limit up to 14 days. 

 

Silkworm Improvement

  1. Productive Bivoltine hybrids   like CSR2 x CSR4 and CSR2 x CSR5 (shell ratio- >23.0%; raw silk -19-20%; average cocoon yield- 70-80kg /100 dfls; renditta-5.2 to 5.5 and silk grade-3A to 4A), CSR12 x CSR6, CSR3 x CSR6, CSR16 x CSR17, CSR3 x CSR6 and CSR16 x CSR17 (average cocoon yield of 60-70kg /100; raw silk-18- 20% and silk grade-2A to 3A) for commercial exploitation during favorable months during September to February.
  2. Robust Bivoltine hybrids of relatively temperature tolerant    like CSR18 x CSR19 and Chamaraja (survival- >80 % @ 36±1°C; average cocoon yield-60 – 70 kg/100 dfls; renditta- 5.5 to 6.0 and silk grade- 2A to 3A) for rearing throughout the year.
  3. Double hybrid for high egg recovery   like (CSR6 x CSR26) x (CSR2 x CSR27) for rearing foundation crosses at P1 level for high egg recovery (10 –15 % more).
  4. Bivoltine hybrid for longer filament   like CSR48 x CSR5 (filament length- >1300m; thin filament size-2.45d; relatively tolerant to high temperature-77% survival @ 36±1°C and 85±5% RH; low boil-off loss-23.8%).
  5. Productive bivoltine hybrids with high silk content   like CSR21 x CSR16 (raw silk: 20.9%; survival- >80% @ 36 ±1°C and 85±5 % RH; high level of cocoon uniformity- SD 7.2 and low boil-off ratio-23.6%).
  6. Bivoltine hybrid of shorter larval duration and superior characters   like SD7 x SD12 (larval duration-28 h; pupation rate- >90%, cocoon weight- 2.076 g and shell ratio- 24.4%).
  7. Bivoltine hybrid of superior characters    like CSR48 x CSR5 of thin filament size, CSR2A x CSR4A and BL-67A x CSR 101 for artificial diet during chawki worm stages, 1HT x 7HT, 2HT x 6HT and 8HT x 5HT tolerant to high temperature (36±10C), high humidity (85±5 %) and resistance to BmNPV and BmIFV @ 1x105 PBOs/ml. The above hybrids are characterized with superior qualitative and quantitative characters like higher cocoon yield, higher renditta and gradable silk etc.
  8. Productive Multivoltine x Bivoltine hybrids   like Cauvery and Jayalakshmi (average cocoon yield- 60-70 kg/100 dfls; survival-90-95 %; shell ratio- 20 - 22%; renditta- 5-6; silk grade- 2A to 3A) for commercial exploitation under irrigated areas throughout the year.
  9. Region specific productive Multivoltine x Bivoltine hybrids   like BL23 x NB4D2 (26 kg /100 dfls with 8.5 renditta) under rain fed and BL24 x NB4D2 (47 kg /100 dfls and 7.5-8 renditta) under irrigated condition with gradable silk of 3A.
  10. Season specific productive Multivoltine x Bivoltine hybrids   like for spring season (CSR6 x Pam101, Pam101 x A70, RSJ13 x RSJ15 and RSJ14 x RSJ11), summer season (Pam 111 x B72 and A70 x CSR6), and autumn season (A70 x CSR6, Pam 112 x A60, RSJ3 x RSJ1 and RSJ3 x RSJ4).
  11. Sex limited Multivoltine x Bivoltine hybrids    like PM x CSR8 (SL) for separation of male / female pupa through cocoon color in grainages. Four sex-limited colored bivoltine breeds viz., SL4, SL5, SL6 and SL7 for better productive traits like >90 percentage pupation and 22% SR this male Bivoltine component with multivoltine females minimizes the production cost of Cross Breed layings.

 

Silkworm Productivity

  1. Multi-bivoltine hybrids of higher feed conversion efficiency like BL68 x CSR5.
  2. Promising Bivoltine hybrids with higher performance at field level   like CSR2 x CSR5, CSR2 x CSR4 and CSR18 x CSR19 (average cocoon yield- 56 and 70 kg/100 dfls; renditta- 6-6.5; silk grade- 2A – 4A).
  3. Evaluation of season specific hybrids   showed maximum shell ratio of 23.63% in CSR2 x YS3 out of 113 hybrids reared during spring 2001; and Pam109 x KY1 recorded maximum shell ratio of 22.13% out of 91 reared in autumn. Among the multivoltine hybrids evolved, hybrids namely Sharavati, Cauvery and Tippu have a potential to yield about 70 kg/100 dfls with a filament length of 900 m and silk grade of 2A-3A.
  4. Application of Phyto-ecdysteroid   on CSR hybrids to shorten rearing period and completes spinning within 18 hr after mounting against 26 to 47 hr under normal rearing conditions.
  5. Semi synthetic artificial diet   for rearing young age silkworms.
  6. Improved Tropical Bivoltine silkworm rearing technology package   for young and late age worms together with proper incubation method for successful crop.

 

Silkworm Protection

  1. Sandwich ELISA assay   for detection of pebrine spores up to a concentration of 10 4 /ml. using polyclonal antibodies (from Rabbit) and monoclonal antibodies (from mouse) MA-575.
  2. Silkworm body disinfectant   like ‘Vijetha’, ‘Vijetha Supplement’ and ‘Resham Jyothi’ to prevent disease outbreak.
  3. ‘Uzicide’ - an ovicide against Uzi fly and ‘Uzi trap’ - a chemical formulation to trap the adult flies to control the menace of uzi (a major pest of silkworm) infestation.
  4. IPM technology package   for the control of Uzi fly through Nesolynx thymus along with Uzicide and Uzitrap. Dermestid beetles causing damage to seed cocoons in grainages be controlled by mechanical removal of grubs / adults and spraying Deltamethrin (0.03%) in the cocoon storage rooms. An insecticidal based chalk stick developed against ant attack in rearing house.
  5. Simple staining technique   for effective detection of intermediary stages of N. bombycis (Pebrine spores) in larval mid-gut tissue.
  6. Eco-friendly and biodegradable chemical based bed disinfectants   utilizing 7 plant products and 4 eco-friendly products for effective management of common pathogens of silkworm.

 

Silkworm Rearing Technology Innovation

  1. Egg transportation bag   provides optimum environmental conditions during transportation of silkworm eggs.
  2. Low cost incubation device    for the incubation of silkworm eggs.
  3. Loose egg incubation frame    toprovide optimum environmental conditions duringincubation for loose eggs, these frames are also useful during incubation, black boxing and brushing. Adopted in all NSSP / DOS grainages engaged in bivoltine egg production.
  4. Blue polythene sheet during chawki rearing    to reduce leaf drayage and reduce leaf input cost.
  5. Wrap up method   to avoid moisture loss (all four sides of the paraffin paper are folded from the rearing bed to increase humidity by 15-20%). This technique gives an additional 3-4 kg more cocoons per 100 dfls at no extra cost.
  6. A simple device for preservation of chawki leaf    (made of a rectangular bamboo tray, bamboo mat and a central funnel) in which chawki leaves can preserve for 10-12 hours without any deterioration in leaf quality and leaf drayage.
  7. Plastic bottlebrush mountage    to help silkworm to mount itself thereby save 40% time towards labour.
  8. Jobarai method of mounting   to save 20% time towards labour for mounting silkworms manually and harvest quality cocoons.
  9. Nylon net rearing technique   for tasar silkworm larvae has been devised.

 

Innovations in Sericultural Machines

  1. Mulberry Pruning Machine attached to power tiller   to prune 15 cm dia. stumps from one acre of mulberry plantation in 5 hr.
  2. Machine for preparation of Cuttings   to facilitate quick preparation of cuttings @ 2000 cuttings/ hour.
  3. Shoot crushing Machine    to crush shoots into small bits / pieces @ 250 – 300 kg shoots/ hour.
  4. Litter separator machine   for separation of left over leaves and litter for use in biogas plant.
  5. Cocoon De-flossing Machine    to de-floss cocoons @ 60 kg/day against manual de-flossing of 10 – 12 kg/day.
  6. Powder duster    to dust disinfectants over silkworm body in prevention of silkworm diseases.

 

Non-Mulberry Host plant and Silkworm

  1. Standardization and recommendation of micro propagation technique    for Terminalia arjuna cultivation. Six strains of Antherea proylei was evolved and 82 genotypes of Terminalia arjuna and T. tomentosa were screened for genetic selection of high yielding ones.
  2. Survey and collection of wild tasar cocoons   from various eco-regions of Bihar yielded five promising eco-races. 9 biotypes, 4 evolved lines and 3 mutant lines were evolved based on Blue, Yellow and Almond colour. Raily, Modal and Daba as well as 3 hybrid combinations Sarihan x Laria, Sarihan x Daba and Laria x Modal were identified as best hybrids for most of the commercial characters.
  3. Adoption of seed cocoon selection procedure and use of cooling device   to reduce preservation loss upto 14.8% in Trivoltine [TV] and 21.1% in Bivoltine [BV] breeds. The mating percentage of moths rose to 93.9% in Trivoltine [TV] and 94.7% in Bivoltine [BV]. Overall, the egg production increased to 49.3% in TV and 60.1% in BV.
  4. Egg laying nylon bag    where the average ovipositor period is 178 hr and fecundity of 48 hr. Female moth preservation frame designed and fabricated to prevent pre-mating ovipositor, up to 20 hr without any loss of eggs.
  5. New moth examination technique   for pebrine detection through pricking method developed over the conventional method of moth crushing and discarding.
  6. Integrated Tasar Rearing Technology Package   includes incubation, brushing of neonate larvae, feeding and guarding young and late age larvae against diseases, pest and predators.
  7. Ideal grainage house and techniques    for Tasar egg production.
  8. Tasar Keet ousadh   for control of Tasar silkworm disease was developed.
  9. Comprehensive package for chawki garden maintenance   to enhance production.
  10. Sun-pack collapsible mountages   for indoor cocoon spinning for quality cocoons.
  11. Foliar spray   with desired level of bacteria during rearing consistently to reduce virosis and bacteriosis and significant gain in effective rate of rearing.
  12. Neem based compound (Azadiractin)    against pest of silkworm larvae.
  13. Integrating cultural, mechanical and active compound of neem derivatives   as suitable control measures against major defoliators of primary tasar food plants.
  14. Biological control measure against Uzi fly   includes - nucleus culture of N. thymus, Tetrastichus howardi, Trichopria spp., Dirhinus spp. and Brachymeria lasus maintained on the puparia of uzi fly.
  15. Nursery technique    for raising of som (Machilus bombycina) seedlings.
  16. Oviposite device    for muga silkworms.

 

Post Cocoon Technology

  1. Biopril-50   a substitute for dry reeling reeled on Tasar Reeling Charkha (TRC); spinning of tasar silk waste, blends with the fibers on pedal spinning wheel and NMC along with improved preparatory processes of weaving were transferred for commercial use.
  2. Standardization of tasar cocoon processing / cooking technologies   of different commercial cocoons on TRC and Motorized /Pedal operated reeling cum twisting machine.
  3. Multi-fuel smokeless economic oven reeling machine    an improved charaka and multi-end reeling machine capable of producing gradable silk of A-B grade.
  4. Silk knitted fabrics   in light and medium weight range in all silk and combination of Silk-Cotton and Silk-Modal yarn. The blends have silk on the face of the fabric and cotton or modal yarn on the inside/back of the fabric, combining the luxury of silk and comfort of cotton, at the same time reducing the cost of the fabric substantially.
  5. Dupion silk reeling machine and technology package    for production of superior grade dupion raw silk (CSTRI, Bangalore). The advantages of the new dupion silk reeling technology are- higher renditta in multivoltine cocoons, less de-gumming loss, improve quality character of dupion raw silk produced and economics of the technology indicate profitability than that of conventional technology. These models can cater the needs of small-scale charka reelers and reelers who have better facilities like boiler and cooking equipments.
  6. Bivoltine silk reeling technology package    to produce International grade raw silk suitable to Indian conditions. In addition, long skein book making machine, reel permeation chamber, stationery pressurized cooking and pressing disc etc. developed by CSTRI, Bangalore demonstrated in the reeling units.

 

Seri-Biotechnology

  1. Identification of DNA marker for NPV resistance in silkworm   through multi-institutional net work project (CDFD, Hyderabad and CSB/state level institutions).
  2. Identification of DNA markers linked to QTLs    (cocoon weight and cocoon shell weight) through collaborative project. Code for anti-viral (BmNPV) protein partially characterized.
  3. Genetic linkage map for the silkworm    established employing 518 simple sequence repeat or microsatellite markers.
  4. Large numbers of Expressed Sequence Tags (ESTs)    have been made available to the scientific community (as India joined “International Consortium on Lepidoperon Genomics”) both for mulberry and non-mulberry silk.
  5. High yielding productive silkworm hybrids    (viz., Swarnandhra, Hemavathy and Kalpavatharavu) developed using DNA marker technology and released to farmers of Andhra Pradesh, Karnataka and Tamil Nadu.
  6. Luciferase and green fluorescent proteins  were successfully expressed utilizing silkworm as a bioreactor (Indian Institute of Science, Bangalore).
  7. Process for degumming of silk with fungal protease enzyme    has been standardized and found economically viable without chemical hazardous.
  8. Mapping populations of mulberry   for water use efficiency and genotyping of trait-specific mapping population of mulberry is under progress.
  9. Transgenic mulberry lines    with HVA-1 gene for abiotic stress tolerance have been developed (University of Delhi). Field evaluation has been initiated jointly with sericulture institute.

 

 

Potential, strengths and challenges of sericulture industry in India

R&D achievements like development of indigenous mulberry varieties with highest leaf yields in the world, new bivoltine silkworm hybrids eminently suited to the tropical regions of the country, farmer-friendly technologies, cost-effective new package of practices for cultivation of food plants, rearing and reeling coupled with huge natural and man-made resources and trained manpower clearly indicates the future prospects of sericulture industry to emerge as a promising indicator of economic development for the upliftment of the socially deprived communities and the downtrodden. The strengths, weakness, opportunities and challenges (SWOT analysis) of Indian silk industry have been given in Table 6.

 

 

Table 6:  SWOT analysis of the Indian silk industry

Strengths

Weakness

Opportunities

Threats

Large production base, availability of skills, land and labour.

Gaps in technology transfer and extension support.

Generation of rural employment and reduction of migration to urban areas.

Falling international prices and heavy dumping from China at low prices.

Established infrastructure, availability of silkworm breeds / hybrids.

Inadequate market accessibility, poor linkage among different stake holders.

Liberalization policies of Govt. of India in line with WTO Agreements.

Unpredictability of China’s silk policies.

Low investment, short gestation period and higher returns.

De-centralized nature of the industry inhibits financial institute from extending financial support to the sector.

Reduction of production of silk even by traditional silk countries like Japan, USSR etc.

Inability of the silk industry to react and adopt to the changing needs in terms of quality both for the domestic and export markets.

Easily adoptable technologies and strong domestic demand-pull.

Lack of quality based pricing system in the market, frequent price fluctuations and large scale imports from China at low prices.

Garment exports are on a steady increase with huge employment opportunities.

Lack of awareness in the domestic market to respond to the demand-driven milieu.

 

 

 

Seri-bio-diversity:    Among 34 mega biodiversity countries in the world, India is home to many species of insects with a diverse silk moth fauna. In addition to the diverse silkworm races, there are vast genetic resources of mulberry, tasar, muga and eri host plants spread over diverse geographical locations. This offers a great opportunity for economic utilization of the natural flora and fauna. However, due to deforestation and destruction of habitats, there is a challenge to bring about development without disturbing the ecological balance.

 

Sericulture and national economy:   In India, sericulture related activities ensure the livelihood security of over six million families spread over in some 59,000 villages across the country. The silk sector is also a valuable foreign exchange earner for the country. The export earnings stood at Rs. 3,338 crores during 2006-07. In addition, there is an opportunity to double the export earnings with the free trade atmosphere in Europe and USA. It is estimated that India needs 25,000 MT of raw silk per year to meet its domestic requirement. The growing demand of silk in the domestic market can make the industry a valuable enterprise which in turn can provide employment for the rural masses ensuring assured economic returns at the individual family level.

 

Sericulture and women empowerment:   Women contribute to a little less than 50 % of the country’s population and most of them are largely rural based, deriving their livelihood through agriculture and other land based activities, either as family members or wage earners. As a cottage industry, sericulture provides ample wok for women in the rural areas particularly in silkworm rearing and reeling, while men, largely work in the field and in weaving. The involvement of women in different activities of sericulture is about 53 % and their contribution in the on-farm activities understandably is lower than that in post-cocoon activities (Table 7). Sericulture is an ideal avocation for women because of the following facts-

 

 

Table 7: Involvement of women in different Sericultural activities

Sl. No.

Activity

No. of districts

No. of villages

Sericulture families

Involvement of women (%)

1.

Silkworm seed production

10

14

082

20.46

2.

Mulberry cultivation

07

14

422

49.55

3.

Silkworm rearing

07

14

422

49.67

4.

Silk reeling

06

13

392

48.81

5.

Silk spinning

02

20

200

80.00

6.

Silk throwing (twisting)

04

06

096

56.34

7.

Silk weaving

06

12

267

49.02

8.

Dyeing – Printing of silk yarn and fabrics

04

06

071

41.00

9.

Silk bye-products

01

08

050

65.00

10.

Silk and Milk production

04

15

300

75.00

Total / Overall

47

107

2002

53.45

Source: Central Sericultural Research and Training Institute, CSB, Mysore

 

 

Sericulture and rural development:   Sericulture being a farm-based enterprise is highly suited for both large and small land holdings, with low capital investment. The very nature of this industry with its rural based on-farm and off-farm activities and enormous employment generation potential has attracted the attention of many planners and policy makers to recognize the industry as one of the most appropriate avenues for socio-economic development of a largely agrarian economy like ours. Generally, silk goods are purchased by the urban rich and middle-class consumers and it is estimated that around 57 % of the final value of silk fabrics flows back to the primary producers in rural areas. Sericulture can also play a very vital role in alleviating rural poverty due to its high work participation rate and thereby can check migration from rural to urban areas.

 

Sericulture and employment generation:   The percentage of population below the poverty line ranges from 47.15 % in Orissa to 12.72 % in Kerala. In major silk producing states it is about 30 % on an average (Table 8). Raw silk production is the most appropriate tool to provide gainful employment to these poorer sections of the society, as net incomes range from Rs. 12,000 to 70, 000 per annum depending upon the variety of the silk to be produced and the unit area (under host plants). It is estimated that sericulture can generate employment @ 11 man-days per kg of mulberry raw silk production (in on-farm and off-farm activities) through out the year (Table 9).

 

 

Table 8: State-wise status of below-poverty-line families (1999-2000)

State

% population below poverty line

State

% population below poverty line

Andhra Pradesh

15.77

Maharashtra

25.02

Assam

36.09

Madhya Pradesh

37.43

Bihar

42.60

Orissa

47.15

Gujarat

14.07

Tamil Nadu

21.12

Karnataka

20.04

Uttar Pradesh

31.15

Kerala

12.72

West Bengal

27.02

Source: Planning Commission Report, Article: K. Venkatasubramanian.

 

 

 

Table 9: Activity-wise employment generation in Mulberry sericulture (per ha.)

Activity

Employment generation

Man-days

Man-years

A. Mulberry cultivation and silkworm rearing

     a. Mulberry cultivation

585

 

     b. Leaf / shoot harvesting

320

 

     c. Silkworm rearing

350

 

Sub-total

1255

5.020

B. Reeling of silk cocoons

@ 300 mandays per 1000 kgs of reeling cocoons (@ 8.0 renditta; 760 kgs cocon / ha.; 95 kgs raw silk / ha.)

2250

9.120

Total (A + B)

3535

14.140

C. Twisting

@ 220 g of silk per mandays

432

1.727

D. Weaving

  Handloom @ 0.13 kg per manday

438

1.752

  Powerloom @ 0.3125 kg per manday

122

0.486

Sub-total (Weaving)

560

2.238

E. Printing and Dyeing

@ 40 mandays for 40 kg of raw silk

95

0.380

F. Finishing

@ 751 mandays for 40 kf of raw silk

1784

7.135

G. Silk waste processing

@ 18.775 mandays per kg of raw silk

26

0.104

Total (C to G)

2896

11.58

Grand Total

6431

26

Source: Central Silk Board, Bangalore.

 

 

Sericulture and higher remuneration:   Sericulture as a remunerative crop can suit all categories of farmers from small/marginal farmers with meager resources to a large farmers. With short gestation periods, the returns are quick. The net returns in case of mulberry sericulture (when a farmer has one acre of mulberry plantation using family labor), is estimated at about Rs. 48,000 per annum. Mulberry is highly amenable to inter-cropping. Economics of mulberry with inter-cropping of vegetable for 3,700 sq. meters is given in Table 10.

 

 

Table 10: Economics of mulberry as an inter-crop with vegetables

Crop combination

Additional income (Rs.)

Mulberry + Palak

17422

Mulberry + Methi

6026

Mulberry + Raddish

3869

Mulberry + Beans

4953

Source: CSR&TI, CSB, Mysore

 

 

Sericulture and new emerging areas (value addition and product diversification):   It is imperative that adequate thrust on non-traditional uses of silk could create a positive pressure in the sector to concentrate on high quality raw material for high value addition leading to a quantum leap forward.

The non traditional areas are:

  1. Medical application
  1. Cosmetics such as facial masks, dermal lotions, powders etc.
  2. Liquid silk
  3. Interior home decor and handicrafts

 

 

 

Conclusion

Silk is a highly valued textile fiber of animal origin. It is used almost entirely for the production of high quality textiles. The sericulture industry is unique for more than one reasons. It is based on agricultural output viz., cocoons and cottage based labour intensive in nature. The industry comprises of reeling, silk preparatory and weaving, silk knitting, silk wet and processing consisting of degumming, dyeing, printing and finishing besides garment manufacturing. These activities in turn support the ancillary enterprises of marketing, manufacture and by-product utilization comprising of spun silk yarn manufacture and papae oil extraction. Thus, a lot of value is added to the product at each stage of the industry.

 

Reeling forms a vital link in converting the agricultural produce viz., cocoons into an industrial output yarn. Reeling involves a series of intricate processes while converting the cocoons into raw silk. The reeling sector in India is cottage based and highly decentralized, employing a variety of reeling devices viz., charkha, cottage and domestic basins, semi-automatic, automatic and multi-end reeling machinery. Generally, at the village level, there are charakhas which accounts nearly 50 % of the total raw silk production in the country. The charkha silk yarn though of poor quality has a distinct identity in the market and is generally associated with bulkiness and preferred as weft yarn largely by the handloom weavers.  Central Silk Technological Research Institute, Central Silk Board, Bangalore ‘Multi-end reeling machinery package’ (an improvement over the cottage basin) was introduced as the most appropriate technology to handle the available quality of cocoons to produce gradable quality raw silk. In the intermediate level, there are domestic basins and cottage basin reeling devices while at upper end there are multi-end reeling machines, semi-automatic and automatic reeling machines. In weaving sector, about 70 % raw silk is consumed by the handlooms while the power looms consume only 30 %. Thus, the pre-requisite of silk industry is availability of raw silk of right quality in adequate quantities at competitive prices consistently. Therefore, it is important to link such units with identified cocoon growers. Such units may also think of procuring the raw material through a system of contract or corporate farming.

 

Some initiatives like cocoon testing in some select markets, raw silk testing in the silk conditioning and test houses and technical service centres across the county by the Central Silk Technological Research Institute, Central Silk Board, Bangalore has created visible impact to bring awareness about quality among the rearers, reelers and weavers. This is important to achieve quality silk of international standard. Recently, Central Silk Board has started a testing laboratory for Silk and Zari at Kancheepuram to facilitate customers, producers and other stakeholders for spot testing of silk and zari material without any destruction to the products by x-ray analysers. More importantly, ‘Silk Mark’ Scheme is introduced by Silk Mark Organisation of India (SMOI), a registered society, sponsored by Central Silk Board, Ministry of Textiles, Government of India.  The Silk Mark is a quality assurance label for the assurance of pure silk and in addition serves as a brand for generic promotion of Pure Silk. The Silk Mark is under the process of registration as a Trade Mark. 

 

Indian silkworm breeds are multivoltine (i.e., they produce several broods a year) and though, good progress has been achieved in cross breed (multivoltine x bivoltine) silk production, the quality still remains incomparable to that of Chinese breeds which are bivoltine. In spite of abundant natural resources, socio-economic benefit of the sector like generation of employment for the large sections of tribals and marginalized rural men and women,  growing export market as well as large domestic demand, a variety of problems have kept Indian sericulture away from achieving its true potential. These may include unhygienic conditions and diseases prevalent during silkworm rearing, mediocre quality of silkworm breeds and sub-optimal processing technology, lack of proper seed organization system and poor quality seed production, low technology adoption by the stakeholders, inadequate/poor extension efforts, age-old practices of post-cocoon operations, absence of quality certification and quality-linked pricing system and poor linkages among the four production sub-systems viz., seed, cocoon, yarn and fabric. In this context, some possible approaches have been suggested below and a strategic model has been outlined in Fig. 3.

 

 

Fig 3: A strategic model to strengthen and promote sericulture industry in India

 

 

 

 

 

References

 

 

 

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