the silkworm

Impact of Social Networks on Farmers' Choice of Technology

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sun, 12 Jan 2025 11:51:00 +0000

Social Network Analysis (SNA) is a powerful tool for understanding the dynamics of social networks and their influence on the adoption of technology among farmers. By examining the interactions and relationships within a network, SNA can reveal how knowledge, information, and innovations are shared among its members. This article explores the impact of social networks on farmers' choice of technology, with a focus on the Sericulture Innovation System (SIS) in Karnataka, India.

Understanding Social Network Analysis

SNA is based on the premise that network ties play a crucial role in the dissemination of knowledge and innovations. The strength of these ties is determined by the number, frequency, and duration of interactions between actors, as well as the reciprocal services exchanged. In the context of farming communities, these ties can significantly influence the adoption of new technologies. The relationships between actors in a network are often represented by binary ties, which indicate the direction of information flow and can elicit an adoption response. The strength and direction of these ties are essential for understanding how innovations spread within a community.

The Sericulture Innovation System under investigation encompasses five villages in Sreerangapattana Taluk, Mandya District, Karnataka. This network includes 358 sericulture farmers, 30 Chawky Rearing Centres (CRC), five Chawky agents, 11 input suppliers, eight mulberry nurseries, eight mountage rental agencies, three cooperative societies, six markets, and eight government extension agencies.

Measures of Network Cohesion

The network's cohesion, or interconnectedness, is a critical factor in its effectiveness. Cohesion is defined as the desire of individuals to maintain their connection with a particular group. It is important for achieving common tasks and is measured by various metrics, including average degree, network diameter, graph density, modularity, connected components, clustering coefficient, and path length.

The SIS network has an average of 9.7 links per node, a network diameter of 6, and an average path length of 2.6. However, only 5% of the potential links between farmers are present, indicating underutilization of the network's potential. This suggests that there is ample scope for promoting linkages between actors to enhance the network's effectiveness.
The network's cohesion can be further analyzed by examining the centrality measures of its actors. Centrality measures identify the most influential actors in a network and can provide insights into the flow of information and innovations.

Centrality Measures and Key Actors
Centrality measures include in-degree centrality, out-degree centrality, betweenness centrality, and eigenvector centrality. These measures help identify the most prominent actors, or "key players," in the network.
In-degree centrality measures the popularity of an actor, based on the number of times they are mentioned by others in the network. In the SIS, markets, mountage rental services, CRCs, Chawky agents, and extension agents exhibit high in-degree centrality, indicating their frequent approach by other actors. Among farmers, those who adopt new technologies (adopters) are more frequently approached for technical information.
Out-degree centrality measures the potential of actors to introduce innovations. Adopter-farmers are shown to be the best disseminators of innovations, aligning with previous research. This suggests that adopter-farmers play a crucial role in spreading new technologies within the network.
Betweenness centrality highlights the role of actors as intermediaries in information dissemination. Farmers who have adopted new technologies exhibit the highest betweenness centrality, accounting for 46.3% of all ties in the SIS. This implies that these farmers are key intermediaries in the network and play a significant role in the dissemination of innovations.
Eigenvector centrality considers the influence of an actor's connections. In the SIS, markets and rental services have high eigenvector centrality, indicating their importance in the network. However, caution is advised in interpreting these results, as high eigenvector values may arise from the inevitability of these organizations to farmers.

The Role of Farmers in Technology Adoption

Farmers, especially those who adopt new technologies, play a decisive role in the dissemination of knowledge within the SIS. The analysis reveals that opinion leaders in the network are predominantly non-adopters, suggesting that their influence may not encourage further adoption. This highlights the need for targeted extension interventions to convert these opinion leaders into adopters and advocates of new technologies.
The centrality measures of the top ten actors in the network indicate that farmers are the sole players in terms of closeness and betweenness centrality. This underscores the strong influence of farmers over other actors in the network as opinion makers. Among the most influential players are the farmer-cum-Chawky agent (F27), Market no.1 (M1), Extension agent no. 4 (E4), CRC no. 5 (C5), and Chawky agent no.1 (A1).

Policy Implications

The SNA of the SIS reveals certain policy implications. First, there is a need to promote linkages between actors to fully exploit the network's potential. Second, extension policies should focus on creating favorable opinions among adopters and utilizing their influence to spread innovations. Third, targeted interventions are required to convert strong opinion leaders into adopters.
One particularly striking finding is the leadership roles played by the government extension officer (E4) and the farmer-cum-Chawky agent (F27). The SNA indicates that the village community has polarized into two groups under their respective influence. While these two leaders are personally well-connected, their personal relationship has not resulted in networking between the two groups they represent.
Figure shows polarization of the village community into two separate networks around two different influencers. The green bubbles represent the members connected with extension officer E-4 as central node and the pink bubbles those, connected with farmer F-27 as central node (click to enlarge the picture)

This calls for policy intervention at two levels:
Opening Channels of Communication: There is a need to create platforms for interaction between the two groups. This can be achieved through group discussions, focus group discussions, demonstration programs, and off-farm training programs. By facilitating communication between the groups, the favourable impact of new technologies can be shared more effectively.
Targeted Extension Interventions: Given the strength of SNA in identifying key players, extension policies should focus on converting strong opinion leaders into adopters. Recognizing and educating these leaders can help them become strong advocates of new technologies, thereby enhancing the overall effectiveness of the network.

Conclusion
SNA provides valuable insights into the impact of social networks on farmers' choice of technology. In the SIS, farmers who adopt new technologies play a crucial role in disseminating knowledge and innovations. However, the network's potential is underutilized, and opinion leaders are predominantly non-adopters. By promoting linkages and targeting interventions, policymakers can enhance the adoption of new technologies and improve the overall effectiveness of the network.
The findings from the SNA of the SIS highlight the importance of social networks in the adoption of technology among farmers. By understanding the dynamics of these networks, policymakers can design more effective extension programs and interventions to promote the adoption of new technologies. This, in turn, can lead to increased productivity and sustainability in farming communities.
In summary, the impact of social networks on farmers' choice of technology is significant. The relationships and interactions within a network can greatly influence the dissemination of knowledge and innovations. By leveraging the insights gained from SNA, policymakers can create targeted interventions to enhance the adoption of new technologies and improve the overall effectiveness of agricultural innovation systems.

Facial mask and biomaterial applications of Nano silk sericin

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Mon, 11 May 2015 10:44:00 +0000

R.K.Pandey, Regional Sericultural Research Station, Jammu 181101, pandeyjammu@gmail.com

What is Nanotechnology?

Nanotechnology, "the manufacturing technology of the 21st century," is defined as the understanding and control of matter at dimensions of roughly 1 to 100 nanometers (billionths of a meter, or 10 m.) A nanometer (nm) is one-billionth of a meter, or a millionth of a millimeter - smaller than the wavelength of visible light and a hundred-thousandth the width of a human hair. At this scale, unique properties of materials emerge which can be applied to produce technologies and products with entirely new abilities and applications. Nanotechnology (NT) involves imaging, measuring, modeling, and manipulating matter only a few nanometers in size. Nature already uses nanotechnology in the molecular machinery of every living thing. Nature's designs are working examples to us of what can be made. However, rather than using trial and error, we can apply intelligent design principles to our creations.

The Nano Age

According to futurist and inventor, Raymond Kurzweil, the Nanotech Age is expected to begin between 2025 and 2050, bringing an end to the current Information Age which began in 1990. Coming is a Nano Revolution that will be at least as transformative as the Industrial Revolution (perhaps much more so), but packed into just a few years. Well beyond present-day nanotech applications, mature "molecular manufacturing" or "molecular nanotechnology" will enable us to manifest our dreams (or nightmares). We are nearing the ability to build molecules out of atoms mechanochemically, and to use these molecular building blocks to construct virtually any substance or device we can conceive of. This most powerful technology of all will radically transform and extend the capabilities of practically every area of human endeavor by exploring the ultimate limits of fabrication. Nanotechnology will become the most powerful tool the human species has ever used. With it, we will literally fashion the world of tomorrow into whatever we so desire.

Nanomaterials

Materials having morphological features smaller than 100 nm in at least one dimension are Nan materials. This classification includes thin films, quantum dots, etc. When matter is reduced to the nanoscale (1 - 100 nm,) the effects of increased surface-area, in tandem with quantum effects, begin to dominate material properties. As a particle's size decreases, a greater proportion of its atoms are found at the surface compared with those inside. Larger surface area equals greater reactivity. Quantum confinement results in size-dependent property changes, meaning materials with nanoscale dimensions (Nano materials) can start to exhibit very different optical, electrical and magnetic properties, (especially as the structure or particle size approaches the smaller end of the nanoscale) compared to what they would on a macroscale. This effect has been likened to an expansion of the entire periodic table of the elements out into another dimension; as though we now have access to many new primary elements which did not exist before, enabling unique/novel applications. For instance, when made into nanoparticles, opaque substances may become transparent (copper); inert materials attain catalytic properties (platinum); stable materials turn combustible (aluminium); solids become liquids at room temperature (gold); insulators turn into conductors (silicon). Materials such as gold, which are chemically inert at normal scales, can serve as a potent chemical catalyst at the nanoscale. Much of the fascination and potential of nanotechnology stems from these unique surface area and quantum phenomena exhibited by matter at the nanoscale. Silk thread is a double strand of the fibroin held together by a substance which is gummy in nature; this gummy substance is the sericin protein. The chemical composition of silk filament is fibroin (70-80%), sericin (19-28%) and other matter plus ash contributes to (1.0-2.0%).

Nano silk sericin

Fig.1 Silk filament

The waste water from silk industry largely contains the sericin group of proteins which are discarded unused and polluting the nearby area. Sericin contains 18 amino acids including essential amino acids. The major amino acid compositions in sericin are 32% of serine, 18% aspartic acid and 16% glycine. The total amount of hydroxyl amino acids is 45.8%, polar amino acid 42.3% and nonpolar amino acid residues 12.2% in sericin.

The waste water of degumming process of silk industry is utilized for the extraction of sericin group of proteins and its conversion to nano particles.

Extraction of sericin

The 5 L waste water is centrifuged in a centrifuge at 4000 rpm for about 10 minutes to remove the suspended particles. The clear supernatant is concentrated in a rotary evaporator to about half of the original volume 2 L. The clear concentrated sericin solution is stored at 4oC for further use.

Preparation of nano sericin

The 48 g of urea is added to a 100 ml concentrated sericin solution to make the final concentration of urea to 8M. The solution is agitated continuously at 60oC for one hour. After cooling at room temperature, the solution is dialyzed using dialysis tubing against distilled water for 48 hrs. The distilled water is changed every 3 hrs, to remove urea completely. The solution is then subjected to lyophilization using Opera freeze dryer at

-55 0C for 24hrs to get nano sericin in powder form. It contains 18 kinds of Amino Acids, including all 8 kinds of human needful ones.

APPLICATIONS

The sericin in nano form can be used in various applications. Recently, Silk sericin has been widely used in biomaterial applications due to its biocompatibility, biodegradability, and anti-oxidative and bioactive activities.

Cosmetics

Because the hydrophilic amino acids proportion reaches 80%, it has extraordinary excellent performance on humidity-control and skin protection as cosmetic materials. The colloid proteins protect and care one's skin and hair, forming the protective velum, keeping the skin moisture, preventing injury on skin stratum corneum and blocking off ultraviolet radiation. The sericin has good moisture absorbing characteristics so it can be used as a moisturizer in the cosmetics and it also gives glow to the skin. The sericin shows gelling property at all conditions. This property can be used to replace the artificial binding agent used in perfume sticks. By making the sericin stable it is possible to increase the porosity in the perfume sticks which makes it easy for burning.

Wound healing

One of the major applications of tissue engineered skin substitutes for wound healing is to promote the healing of cutaneous wounds. As the sericin based hydrogel has the three dimensional cross linking property, it can be used as a scaffold in the tissue engineering effectively.

Anti microbial products

The sericin shows antibacterial properties. It can be widely used in the pharmaceutical products as an antibacterial agent. It is an excellent treatment for the cuts, wounds, burns, sores and skin infections. The sericin based hydrogel can be used in these applications as it can absorb moisture and has antimicrobial property. This property can be utilized to prevent the urinary tract infections. The anti-microbial activity of the Silk Sericin capped silver nitrate against gram-positive and gram-negative bacteria is confirmed.

Sericin is also reported to have diverse biological activities, such as anti-oxidation, anti-bacterium, anti-coagulation and promoting cell growth and differentiation. In the field of regenerative medicine, owing to its biodegradability, easy availability, and hydrophilicity with many polar side groups, sericin is mostly copolymerized, crosslinked, or blended with other polymers to form various scaffolds in order to help obtain improved properties for relevant biomedical applications, such as skin regeneration. Besides being jointly fabricated with other biomaterials, the possibility of using only pure sericin to generate scaffolds has just begun to be explored.

Facial mask paste from silk sericin

Acne, blackheads, white heads and blemishes are a problem that everyone at some point in their life has dealt with and not just in their youth. These issues affect people of all ages for various reasons. Hydrogel Mask provides superior quality over the conventional Serum-soaked cloth masks. Before the hydrogel masks appeared on the market, serum-soaked cloth masks were synonymous with the face masks, appealing to consumers with their ease of use and the great hydrating ability. Despite these merits, some users complain that they do not completely make contact with their skin or some essence ingredients run from the face.

Compared with the traditional standard essence masks, Hydrogel Mask provides extraordinary moisturizing quality that has been proven to be superior to the traditional essence masks by up to 18%.

What’s more, the new concept Thermo-Sensible Water-Soluble gel mask gradually melts its active ingredients into skin, reacting to the skin temperature. Genic has obtained patents regarding thermosensible quality and TCD (Transdermal Cosmetic Delivery System). It also utilizes the bio-matrix method, which is safe for the human body.

This gel mask has a great cooling effect and it keeps skin moisturized as well. The enhanced moistness and adhesive ability guarantees effective delivery of active ingredients into the deeper skin without damage, while resolving the problem of other sheet-type masks’ losing active ingredients.

Fig.2 Silk sericin facial mask

Even though nanotechnology is an emerging field of science greatly exploited in different sectors mainly electronics, energy, environment and health, its application in sericulture is rarely exploited in India and abroad. The research in this sector in India is still at a preliminary stage and also at a conceptual level to understand realistic assessments.

Reference

International Conference on Nano Science and Nanotechnology 2015

Int.J.ChemTech Res.7 (5), 2117-2124(2015)

Occupational health problems in Silk production: A Review

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sat, 15 Nov 2014 09:15:00 +0000

Rakesh.K.Pandey

Regional Sericultural Research Station, Miransahib, Jammu, 181101, India

Abstract

Even though, the Silkworm life cycle is eco friendly, silk industry involves certain health risks such as carbon monoxide poisoning in temperate area like Kashmir due to the use of burnt coal to raise room temperature, handling of diseased worms and excreta with bare hands, use of formaline and bleaching powder for disinfection, use of bed disinfectants made from paraformaldehyde, use of organophosphates pesticides to control mealy bug, leaf roller and white fly, use of chlorpyrifos to control termites. Beside, Grainage workers suffer from moth scales, which trigger asthma and conjunctivitis. While cocoons are put in hot water to loosen silk fibres for unwinding, the workers also put their bare hands in hot water, resulting in blisters in their hands leading to secondary infection, such as dermatitis. About 70 Benzidine based silk colorants such as azo dyes, release carcinogenic aromatic amines. Similarly, heavy metal complex dyes, are known to damage mental and central nervous function, lower energy levels and damage blood composition, lungs, kidneys and liver. Trivalent chromium used to fix silk dyes undergoes oxidation into hexavalent chromium, which leads to skin irritation, ulcers, sensitization and allergic contact dermatitis. Lead acetate used in dyeing silk cloth is a neurotoxin. It affects the human brain as well as reproductive system. Lead also affects reading and reasoning abilities in children. Dye factories across the world are dumping millions of tons of dye effluent into rivers without any effluent treatment. Pentachlorophenol, which is used in spray starch before ironing silk garment to protect from mould attack also, pose severe health problems. Formaldehyde resins routinely applied on silk to reduce shrinkage and wrinkling, cause eczematous rashes. Contact with silk cloth with a pH outside the accepted range (5.5), turns the skin flora out of balance and causes irritation. Dermatitis, narcosis, dizziness, fatigue, nausea, headache, eye irritation, adverse reproductive hazards including increased risk of miscarriage and serious neurological problems can all result from the processes of screen printing, where toluene, xylene and methyl ethyl ketone are used as solvents of the inks, thinners and clean up materials. Several health hazards are also associated with weaving and related activities, which cause stress and strain to weavers. Need of including eco parameters testing in issuing silk mark certificate is discussed

Sericulture industry is labour oriented agro industry employing 70 lakh people (5 lakh are sericulture farmers and the rest are stakeholders such as reelers, twisters, weavers, printers etc.) in India. About 23060 tonnes of silk is produced in India annually, which generates a turnover of Rs.25000 crore of which Rs.2500 crore is exported.

Silk production today is a blend of ancient techniques and modern innovations. The first stage of silk production is hatching the silkworm eggs, which have been previously examined and shown to be free from disease. Larvae are then fed cut-up mulberry leaves and after the fourth molt climb a twig placed near them and spin their silken cocoons. The silk is a continuous-filament fiber consisting of fibroin protein secreted from two salivary glands in the head of each larva, and a gum called sericin, which cements the two filaments together. Pupae within cocoons are killed by steam or fumigation to prevent adult emergence, which would cut and tangle the silk filaments. Cocoons are later softened in hot water to remove the sericin, thus freeing silk filaments for reeling. Single filaments are drawn from cocoons in water bowls and combined to form yarn. This yarn is drawn under tension through several guides and eventually wound onto reels. The yarn is dried, packed according to quality, and is now raw silk ready for marketing. Indian silk industry produces basically four types of silks namely Mulberry, Muga, Tasar, and Eri silk. Karnataka, Andhra Pradesh, Tamil Nadu, Jharkhand, Chhattisgarh, Orissa, Jammu & Kashmir and West Bengal are the major hubs of Indian silk industry. The traditional silk sarees like the Kanjeevaram sarees, Banarasi sarees, Konrad sarees, Mysore silk sarees, Pochampally Ikat sarees, Chanderi sarees, Paithani sarees, Patola sarees, Baluchari sarees, Bomkai sarees, Tasar sarees etc., are the exclusive creations of the artisans who use silk as the base material for these sarees. Among non-mulberry silks, Tasar is mostly produced by tribal people settled in different parts and regions of India.

Workers in sericulture industry are exposed to a number of health hazards. Various reproductive and menstrual risk factors for endometrial cancer have been identified, whereas few occupational or environmental risk factors have been explored. Several studies have investigated exposure to insecticides, specifically Organochlorine compounds, but no consistent associations have been reported. Although solvents are considered endocrine disruptors, the only study to date to specifically address solvent exposure and endometrial cancer detected no association (Wernli et al.2008). An association between occupational exposures and health nested within a large cohort of silk workers in India is reviewed here.

Health risk factors during silkworm rearing

Wani and Jaiswal (2011) reported that majority of the rearers in Kashmir are suffering from health problems like, eye irritation, injuries, back pain, allergies, respiratory problems and headache.

Carbon monoxide

Coal Sigri used in silkworm rearing in temperate Kashmir

Carbon monoxide is known as a silent killer because it has no smell, colour or taste and can be produced by a faulty or poorly ventilated fuel-burning appliance such as partially burnt coal sigri used in Kashmir and other temperate areas to raise room temperature in cold condition. Symptoms of carbon monoxide toxicity consisting of headache, vertigo, nausea and vomiting. We lost a worker at Patnitop (J&K) in rearing room due to CO beyond tolerance level (100ppm). Cherry red lividity is seen in human body due to CO poisoning

Illness caused by unhygienic conditions of rearing

Unhygienic conditions due to accumulation of unutilized leaves and silkworm excreta pose health risk. Any negligence of hygiene leads to silkworm mortality due to two main diseases Grasserie & Flacherie. The dead silkworms, if not removed immediately, putrify and cause illness among rearers.

Health Risk from Formalin used in the disinfection to maintain hygiene

Formaline spray with body mask

HCHO has strong irritant effect on the eyes and nasal mucous, when present in the air at levels exceeding 0.1ppm. HCHO is a carcinogen. 2% solution of formaline is employed for spray in the rearing room and on rearing appliances such as trays in a closed room a day before the onset of rearing work.

Health Risk from Bleaching powder

Contact of bleaching powder with skin and eyes may cause severe injury, burns or death. Use of Only 2% solution is recommended for washing trays and rearing rooms

Health Risk from Bed disinfectant (Paraformaldehyde)

Bed disinfectants employed during silkworm rearing mainly consist of slaked lime and paraformaldehyde. Human Skin contact with bed disinfectants result in sensitization, inflammation of the eye (redness, watering and itching)

Health risk factors in mulberry plantation

Risk from 2,4-D Amine used for broad leaf Dicot weeds

Over the past 40 years, dozens of studies have shown the connection between 2,4-D and cancers of the blood

Parthenium: a problematic weed

Health Risk from glyphosate for monocot weeds

Glyphosate is employed to control monocotyledon weeds such as Liver seed grass, Urochloa panicoides and Kyllinga brevifolia etc.Carcinogenic potential of Glyphosate , at extremely low concentration, is confirmed.

Health Risk from chlorpyrifos for control of termites

Chlorpyrifos is used to control termites’ world over. Poisoning from chlorpyrifos affect the central nervous system, the cardio vascular, and the respiratory system in human being. It is also a skin and eye irritant

Health Risk from-hazardous organophosphate

Dichlorvos (DDVP) is employed to control pest attack on mulberry, such as tukra, leaf roller and white fly. Dichlorvos is known to induce neurophysiological and behavioural changes in human being

Tukra, Leaf roller, white fly in mulberry

Health Risk from moth scales in eggs production (Grainage)

In the process of silkworm eggs production, male and female moths emerge from the cocoons, copulate and female moths lay eggs. The wings of moth are minutely scaled. The scale allergens trigger asthma, and Conjunctivitis. Around 9% grainage workers suffer from these problems.

Health Risk of Dermatitis in Reeling

While Cocoons are immersed in hot water to loosen fibres, workers tend to put their bare hands in hot water to see if the fibres are loosened to pick silk thread for unwinding. Hot water gives blisters in fingers leading to secondary infection like dermatitis

Dermatitis symptoms, reeling process

Health Risk from azo dyes

Government of India has notified Indian Eco Standards (Table-I) and prohibited manufacture and use of Benzidine based 70 dyes, which are known to break down into aryl amines.

The enzyme, azo-reductase, breaks down azo dye molecules into aromatic amines which are then absorbed in the intestine. These are especially hazardous to the workforce. The exporter of silk, have to make sure that their products do not carry any of the azo dyes that are prohibited in the western countries (EU).

Release of carcinogenic Benzidine from azo dyestuff

Typical eco-parameters under the Eco-labels for finished textiles

Health risk from Heavy metal complex dyes

Metal Complex Dyes are known for its fastness properties and hence find application in dyeing of silk. Antimony, arsenic, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, gold, iron, lead, manganese, mercury, nickel, platinum, silver, tellurium,t hallium, tin, uranium,vanadium,and zinc comes under heavy metals category. Heavy metal toxicity can result in damaged or reduced mental and central nervous function, lower energy levels, and damage to blood composition, lungs, kidneys,and liver.

Health Risk from Chromium in metal complex dyes

Trivalent Chromium is used to fix silk dyes. It undergoes oxidation into Hexavalent Chromium. Exposure to Hexavalent chromium is hazardous to human health and increase the risk of developing lung cancer. Dermal exposure to Cr (VI) leads to skin irritation, ulcers, sensitization, and allergic contact dermatitis.

Effect of Hexavalent Chromium

Health risk from Lead absorption

Lead is used in Lead acetate for dyeing of silk cloth, Lead molybdate in pigments used in dyestuffs and Lead nitrate in mordant in dyeing and oxidizer in dyeing .Lead is a neurotoxin – it affects the human brain and cognitive development, as well as the reproductive system. Some of the kinds of neurological damage caused by lead are not reversible. Specifically, it affects reading and reasoning abilities in children, and is also linked to hearing loss, speech delay, balance difficulties and violent tendencies.

Effect of different Lead levels (microgram/decilitre) in blood

From Dyeing effluents

Dye factories across the world are dumping millions of tons of dye effluent into rivers. The dyeing effluents contain azo dyes, chromium, heavy metals etc.

In accordance with a Madras High court order, around 400 dyeing units were shut down by 2012 and their operating licences were cancelled and the power connections snapped. Only the factories that installed reverse osmosis equipment were allowed to operate.

Coloured Dye effluent into Ganga river at Varansi

Health Risk from Pentachlorophenol (PCP) Organochlorine compound such as PCP are used in spray starch before ironing silk saree/garment to protect from mould attack. In humans, its bioaccumulation takes place and poses severe health hazard. Pentachlorophenol is a common ingredient in spray starch that often irritates the lungs.

Mould attack on silk

Pentachlorophenol formula

Health Risk from Formaldehyde resins

Use of formaldehyde in clothing is extremely widespread. There have even been lawsuits alleging high levels of it in Victoria's Secret bras. Formaldehyde is linked to a 30% increase in lung cancer, plus skin/lung irritation and contact dermatitis. It is found in fabrics claiming to be:

Anti-cling, anti-static, anti-shrink
Waterproof
Perspiration-proof
Moth-proof and mildew resistant
Chorine resistant

It is also used in dyes and printing to fix the design and prevent "running". Eczematous scaly rash occurred after the patient wore a cap containing formaldehyde resins in the silk inner lining.

Eczematous rash on forehead due to cap

Health Risk from pH value

Human skin has a pH of about 5.5, acting as a barrier to bacteria, viruses and contaminations. Contact with materials with a pH outside the accepted range turns the skin flora out of balance and causes irritations. Eco mark (India) restricts pH of aqueous extract of the fibres between 4.0 and 7.5.

Health risk from screen printing solvents

The major hazard comes from exposure to the solvents, Toluene,Xylene,methyl ethyl ketone in the inks, thinners, clean-up materials, (permitted<1 .0="" b="" ppm="">

Dermatitis, narcosis, dizziness, fatigue, nausea, headache, eye irritation, adverse reproductive hazards including increased risk of miscarriage, and serious neurological problems can all result from the processes of screen printing

Health Risk of Handloom Silk weavers

Several health hazards are associated with weaving and related activities which may cause stress and strain to weavers and pose several health related risk factors to them

Ailments of silk weavers

Conclusion

Various types of occupational disorders are associated with silk industry such as, respiratory disorders, injuries, eyesight problems, nerve disorders, and carcinogenic skin problems. Most of these health risk factors can be avoided by proper precautions. Awareness programme and local group discussions are essential for improving the health status of these workers. There must be some provision of protecting equipments such as face masks, first aid facility, gloves and proper uniform. Silk mark protects the interests of consumers, who are being cheated by traders by selling spurious products in the name of silk. So far silk mark authorities test cocoons and raw silk only. In order to safe guard health of the consumers, the silk mark should be clubbed with silk testing with reference to eco parameters of Textile testing laboratories as per the norms of Bureau of Indian Standards.

References

Nadiger G.S.(2001)Azo ban,econorms and testing.

Indian J. Fibre Text.Res.Mar-Jun, 55-60.

Wani, K.A. and Y.K.Jaiswal (2011_a) Health hazards of rearing silkworms and environmental impact assessment of rearing households of Kashmir, India.

Nature Environment and Pollution Technology, 10, (1), 85-90.

Wani, K.A. and Y.K.Jaiswal (2011_b) Occupational health risk factors in carpet industry:

A review. Asian J.Exp.Biol.Sci.2 (1), 135-138.

Wernli, K.J.,R.M.Ray, D.LiGao, E.D.,Fitzgibbons,J.E.,Camp,,G.Astrakianakis, W.Li, A.J.DeRoos, Z. Feng, D. B Thomas, and H. Checkoway (2008). Occupational Risk Factors for Endometrial Cancer among Textile Workers in Shanghai, China.

Am J Ind Med. Sep 2008; 51(9): 673–679.

Yousuf, T., I Khan, T. Yousuf and T.Raja (2013) Socio economic profile of silk weavers: A micro level study of Srinagar city. European Acad.Res. 1, (3), June, 319-331.

Key words: Cancer, occupation, silk, textile

Sericulture empowers women in the fragile Kandi belt of Jammu, India

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 04 Jun 2014 06:58:00 +0000

R.K.Pandey, Sulochana Kaul and Anil Dhar

Regional Sericultural Research Station, Jammu 181101, India

Summary

This paper is a narrative on the positive impacts of a women farmer-adoption programme by Regional Sericultural Research Station, Jammu, India. A total of 60 women were adopted for empowerment by way of giving them opportunity to have additional income from sericulture in Kandi area of Jammu, Northern India. The adopted women harvested on an average 45 kg cocoon per 100Dfl’s and earned up to Rs.8330 from silkworm rearing in spring season. The researchers claim that the result of the adoption project is indicative of the positive impact of training; towards better adoption of sericulture technologies among women sericulturists.

Introduction

Mud shed used by Kandi women for silkworm rearing

Silk is the most elegant textile in the world with unparalleled grandeur, natural sheen, and inherent affinity for dyes, high absorbance, light weight, soft touch and high durability and known as the “Queen of Textiles”. Sericuture, the art and science of silk production is a livelihood opportunity for millions owing to its high employment generation potential, low capital intensive nature, while being a highly remunerative agro industry. 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 the planners and policy makers to recognize the industry among one of the most appropriate avenues for socio-economic development of a largely agrarian economy like India. Today, mulberry is cultivated in about 0.192 million hectares in India. Around 6 million people from around 800,000 farm families are engaged in sericulture activities, concentrated mainly in the three southern states of Karnataka, Andhra Pradesh, and Tamil Nadu. The Silk Production Statistics estimated the world silk production to be 152868 metric tonnes. China’s contribution to world silk production is 126000 metric tonnes, and the share of Indian silk production is 23,679 tonnes metric tonnes (CSB, 2013).China and India together account for 97.9% of world silk production.
Among the various states of India, Jammu and Kashmir (J & K) is the oldest bivoltine silk producing state and covers an area of about 7082 ha under mulberry plantation. J &K produces around 133 MT of bivoltine raw silk from 1022 metric tonnes of annual cocoon production

The adoption level of improved technologies of mulberry cultivation and silkworm rearing is very low among J & K farmers. The major constraints are lack of awareness followed by traditional practices. Expensive and cumbersome technologies, lack of awareness, and non-availability of technology are attributed as the major reasons for non-adoption (Qadri et al.2010). Creating awareness and interest among farmers about latest technologies and development of farmer-friendly and cost-effective technologies are needed.

3-tier feeding method to overcome shortage of space

No wonder women are playing a very important role in the sericulture industry. It is seen that the sericulture activity brings regular income to the community without any bias of caste, creed, gender, or religion. As woman have crucial role in the activities of sericulture, it equally creates opportunities and makes them independent socially, economically and politically. It is a well known fact that poverty affects mostly women. 60% of the world’s hungry are women. Women work two-third of the world’s working hours, produce half of the world’s food, but earn only 10% of the world’s income and own less than one per cent of the world’s property. The gender target therefore needs to be bold and strong, moving away from measuring average progress towards focusing on the marginalized groups, such as women living in fragile area.

Cocoon harvest from Eucalyptus plant-shoot mountages

The submontane tract lying in the outer Himalayas of Jammu division of Jammu and Kashmir is locally termed as Kandi belt. Most of the terrain of Kandi is undulated and affected by vagaries of unpredictable weather further aggravated to prolonged dry spell. Moreover, marginal size of holding also adds to the worries of the farmers. In such conditions, something which provides sustainability is the use of traditional knowledge-wisdom developed by the people over many generations.

In Kandi belt of Jammu, women livelihoods mainly depend on rainfed maize and wheat crops. Owing to continuous research and improvement in recent years, sericulture has established its superiority over other principal crops. Employment opportunities in sericulture can be categorized under two heads; viz. opportunities related to mulberry cultivation and silkworm rearing and opportunities relating to silk reeling, twisting, weaving, and marketing. The latter is mostly undertaken in semi urban and urban areas. In the present work it was aimed to empower women of Kandi belt of Jammu through sericulture (mulberry cultivation and silkworm rearing).

Newly introduced plastic tray rearing

Methodology Adopted:

From the female headed families, a total of 60 women were identified by selecting 20 in each Research Extension Center, operating in Kandi belt of Jammu region. Data on family size and structure, land holding, occupation, cast-wise distribution, monthly income, daily expenses, educational status and participation of men, women and children in silkworm rearing practices were recorded. An assessment was made of their level of knowledge and current level of livelihood.

The women were trained at their doorsteps in the following current technologies:

Disinfection and hygiene,

Importance of Chawki rearing,

Care during moulting,

Late age silkworm rearing,

Use of bed disinfectants,

Role of temperature and humidity,

Identification of ripe (ready to spin) worms

Care during mounting,

Harvesting, sorting and marketing of cocoons,

Stifling and storage of cocoons,

Cocoon crafting

Land preparation for mulberry cultivation,

Application of manure and fertilizers,

Importance of green manure,

Improved mulberry varieties/silkworm hybrids,

Insect pests and diseases of mulberry and their control measures.

Demonstrations of silkworm rearing and plantation were carried in the field area of women participants. Thereafter, Chawki reared worms were given to women and cocoon yields were recorded and marketing data was collected. Impact of the peripatetic training was assessed and compared by the analysis of variance.

Results

The cumulative effect of peripatetic training was monitored by observing cocoon yield, price per kilogram of dry cocoons and income from sericulture of the adopted women in the present work.

Yield of Cocoons

It can be seen from Table I that the average yield of cocoons per 100Dfl’s increased from the first year of 37 kg in 2011 to 45 kg in 2013. In Tikri area, the gain was substantial, where average cocoon yield per 100 Dfl’s increased upto 46.89 in 2012 from 29.58 in 2011 and 41.14 kg in 2013. However, the difference in cocoon yield between 2012 and 2013 were not significant in Tikri area. In Barnoti, the cocoon yield increased from 36.44 kg in 2011 to 41.49 kg in 2012 and 48.99 kg in 2013. The cocoon yield in Naushera could not be improved beyond 45 kg per 100Dfl’s during the present work.

Cocoon price

It can be seen from Table II that the average cocoon price of the adopted women in Jammu increased from Rs. 360 to Rs. 585 per kilogram. However, in Tikri area, the gain was more than double, where the cocoon price increased from Rs 329 in 2011 to Rs.711 per kg in 2013.

In Naushera, the cocoon price increased from Rs. 296 in 2011 to Rs. 529 per kg in 2013. And, in Barnoti, the cocoon price increased from Rs. 456 in 2011 to Rs. 517 in 2013.

Income from Sericulture

The average income of the adopted women from sericulture per crop increased from Rs. 3910 in 2011 to Rs. 8330 in 2013. In Tikri, the average income from sericulture increased nearly three times from Rs. 3098 in 2011 to Rs. 9593 in 2013. In Naushera, the income from sale of cocoons increased from Rs. 3552 in 2011 to Rs. 8079 in 2013.

And in Barnoti, the income increased from Rs. 5082 in 2011 to Rs. 7320.

Discussion

Sericulture technologies demonstrated to adopted women in the fragile Kandi belt of Jammu province during peripatetic training led to 39.14% increase in cocoon yield and 34.54% increase in Barnoti area. In Naushera area, the women harvested 45kg per 100 Dfl’S (40000 eggs) in the first year of the project itself and improvement beyond 45 kg could not be achieved during the project period due to the fragility of the area, being very close to Pakistan border. The average yield of cocoons per 100Dfl’S increased from the bench mark of 37.04 kg in 2011 to 45.34 kg in 2013 due to training impact. However, due to general price hike in the market, during the year2013, the income of the women from sericulture increased by 209.78% in Tikri, by 127.49% in Naushera and by 44.03% in Barnoti area.

Women participating in cocoon auction at R.E.C.Barnoti in Kandi belt

It is inferred that the new technologies of sericulture should be popularized by peripatetic training programme. Awareness programme should also be conducted during the field activity as per the need of the season for improving the bivoltine cocoon production.

References

Central Silk Board. (2013)NOTE ON THE PERFORMANCE OF INDIAN SILK INDUSTRY

& FUNCTIONING OF CENTRAL SILK BOARD. 26t h December, BANGALORE-560068

S. F. I. Qadri, M. A. Malik, A. Sabhat and F. A. Malik(2010)

ADOPTION OF IMPROVED SERICULTURAL PRACTICES BY SERICULTURISTS IN BORDER AREA OF KASHMIR.

Int. J. Agricult. Stat. Sci., Vol. 6, No. 1, pp. 197-201

Read Previous stories by the author of this article 1, 2, 3

Contact Author: pandeyjammu@gmail.com

‘Bivoltine is not for small farmer’- TH. Somasekhar

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 26 Feb 2014 16:49:00 +0000

Interview by GK. Rajesh

Dr. TH. Somasekhar is India’s leading silk expert. Recipient of the Louis Pasteur Award (2005) of

Dr. TH. Somasekhar

International Sericulture Commission, he led the country’s silk technology research & development for fifteen years as Director of Central Silk Technological Research Institute (CSTRI). Dr. Somasekhar is a PhD in Fibre Science from University of Strathclyde, Glasgow. He obtained B Tech and M. Tech from Bangalore University and Indian Institute of Technology, New Delhi respectively. In an illustrious career spanning more than three decades he has held many positions such as Head of Textile Technology Division, Silk & Art Silk Mills Research Association, Mumbai, Senior Scientific Officer of Ahmedabad Textile Industry’s Research Association, Chief Technical Advisor of M/s. Swan Silk, Ltd., Bangalore etc. Dr. Somashekar is an internationally renowned expert on textiles especially silk. He is widely travelled and associated with all silk producing countries. In this interview, recorded at his residence at Bangalore, India, Dr. Somasekhar spoke at length about India’s sericulture and silk industry, demystifying popular perceptions on the future of silk as an apparel fibre.

Dr. Somasekhar can be contacted at: thsomashekar@gmail.com

GK: Sericulture is an important agro-industry in many parts of India, especially the South. A large number of stake holders such as farmers, silk reelers, weavers, traders and other manual labourers are involved. Silk has been considered a very important commodity by its Royal patrons and during British Rule. The fact that the first commodity board in independent India was constituted for silk is indicative of the importance attached to it. But the industry has been showing a declining trend over past few years. What do you think are the reasons?

Dr. Somasekhar: For last few years particularly for a decade sericulture has been declining and the decline is due to various reasons. For example in Karnataka, a large track of land which was under sericulture in the past has been lost. The main reason around Bangalore Rural district has been urbanisation. Now the new Bangalore international air port has come up. As a result of that development the lands around it have gone for various purposes other than sericulture. Another reason is perhaps sericulture all along has been a labour intensive activity and we have learnt from experience of other countries that sericulture has thrived and survived as long as the contribution of family labour was in bulk. As it went towards engaging labour from outside the economics has not been working out and then also we have known that as the standards of living among the farming community has gone beyond a certain level sericulture has been lost. Another aspect is that there are many other alternatives for the farming community where, with less effort they are able to earn more. See for example in Karnataka there are more profitable alternatives like horticulture, floriculture etc with ready market and less risk. And then we have not been able to provide a stable market for the producer. The cocoon and raw silk prices fluctuate; something that they never wanted. They have always asked, ‘give us a stable price’.

Another thing that has happened in recent years is imports. Large scale imports have affected the local industry and that has been a major factor. As a nation we may have various compulsions for allowing imports- particularly after globalisation of the markets we have to participate survive and fight it out in the open market and that is something which has not been conducive for the progress of sericulture. So as a result we have seen all these factors put together in various dosages contributed to the decline of sericulture.

Globalisation, in fact could have been an opportunity rather than a threat for development. Many domestic industries utilised it either as a means to get cheap imports of essential raw material or as an avenue for large scale export of domestic goods. But silk industry seems to have failed miserably in utilising this opportunity. What is your observation?

We have seen that while imports have increased the exports have not been increasing. Exports in quantity terms have come down. The case of raw material exports is different. For example silk waste export doesn’t help the local spun silk industry. As such the number of spun silk mills in the country has come down. We had a string of spun silk mills numbering almost a dozen in the private sector. They have all closed down now. The reason is they are not getting raw material at a price which is economical to them. We have all the technologies imported. We have Japanese technology, Italian technology for de gumming and spinning and considerable amount of money have been invested in getting the suitable machinery, the line of machines, required for spun silk manufacture.

Then we also see in the recent years that the import duties on raw silk have been brought down to almost 5% and this is going to have a major impact, a perceivable effect on the growth of the industry. The reason is it is not that we will be getting imported silk at a cheaper rate like in the past. Gone are the days when we could import low quality silk when a lot of silk was made available to weavers at import prices as low as $12-16 per kg. Today the prices have gone up beyond $37-38. So what is happening? We are having bulk imports at high prices. So this is something which is going to create problems. Our own production is not much and at least the farmer and silk reeler would have commanded a better price if the imports were not there. The import price is also closely linked to the availability of local silk. When the local silk availability is low, prices automatically go up and import prices also will be at a higher side. These are the changes that have taken place and sericulture is taking a beating from all angles.

India obtained a couple of anti-dumping sanctions against China in case of cheap imports of silk yarn. Do you think China has been dumping silk in India?

You can’t say dumping. A few years ago cheap silk was coming. But today silk is not cheap. The silk we are importing is expensive. Why that is happening is because we have a lot of demand. There is a huge gap between demand and supply. Our own raw silk production is not meeting the requirement. 7 to 8000 tonnes of raw silk is being legally imported. Our production may not be more than ten thousand tonnes, though we claim that we have 17 to 18,000 tonnes of raw silk. On observing the availability in the field that is the farmer activity, cocoon market activity reeler and weaver activity, I get a feeling that we don’t have the kind of raw silk production that we clam to have. That is the reason we are forced to import so much of raw silk. Our requirement has always been estimated around 24 to 25,000 tonnes. If we had 17 to 18,000 tonnes local production 7 to 8,000 tonnes should have been imported. My own understanding of the weaver’s situation is that they are all not doing silk alone. This is because of the increased prices and as ordinary people can’t afford pure silk. So there is a lot of imitation material and combinations. Cotton and silk, Polyester and silk, polyester alone . . . but you have the same designs. Thus the prices have decreased the demand for pure silks. Therefore I feel that this 7,000 to 8,000 tonnes added to our own requirement may not be 25,000 tonnes. It could be far less. Our own production should be around 10 to 12,000 tonnes and our total requirement should be around 18 to 20,000 tonnes.

As I understood, in the past, there were lot of loop holes in imports and large quantities of raw silk were getting into the country through unofficial channels. But all those have been plugged now and the situation also has changed. There is no incentive for people to import silk when the price is high. Even in China, they are not giving you silk less than $ 37 to 38. The overall market situation is such that we have a gap and because of our own production being low, this gap is being filled by imports.

I was in China a few years ago and I had an opportunity to discuss with the companies which manufacture and sell silk. They have lot of buyers in India. I asked them why have they increased the prices, and we can’t afford silk at $ 37 to 38 and even more. The answer I got was: “after all our interest is to sell more. But we will have to see at what prices we are producing raw silk”. The MD of the company told me that for past few years they have been forced to give double the salaries being paid until then. That has (almost) doubled the cost of production. The standards of living in China have increased and the situation that existed in the past is no more relevant. Given this kind of a situation silk is becoming an expensive material and I don’t think it will be cheap in the future and the kind of prices that we have seen in the past may not come again. In such situation countries like India may see further drop in production. We may feel that China has a monopoly. But in the years to come it is quite possible that their interest may also go down and the total silk availability come down.

Is silk going to stay for ever?

I foresee a situation where we will definitely have less and less silk in the coming years and we have to live with it and kind of decide where we need silk. This is going to be a big question. Do we need silk for apparels? In the recent years we see a whole lot of uses of silk other than apparels. With the total availability coming down we should also look at other possibilities which could open opportunities for expensive silk in much better and more important uses. In bio-medical engineering silk is seen as a scaffolding material. It helps growth of cells in the body. Can we look at these possibilities and expand into these areas? We need not worry oh! We are losing silk. In the years to come we should also plan out sericulture from these angles. When we look at silk for apparel purposes the quantity requirements are too huge and we try to increase productivity, leading to use of large quantities of inorganic fertilizers. That is how the quality of land deteriorates. Diverting silk to non apparel purposes will reduce the quantity demand pressure. This would be far more scientific. When we use silk for bio-medical purposes there shouldn’t be even traces of inorganic material in it. This reduces pressure on environment. Perhaps more such uses may arise.

India implemented at least two ambitious externally aided projects: the Karnataka Sericulture Project (KSP) and National Sericulture Project (NSP) both were declared failure by those who did final assessment. Where did we go wrong? What are the lessons?

KSP & NSP were in many ways projects for the sericulturist, for upgrading himself, to adopt new practices and to accept new technologies. The model of sericulture that we had is something very important. In fact I had projected three models of sericulture existing in different parts of the world.

1. The Indian model which consist of small producer and small converter

2. The Chinese model which has small producer and large converters

3. The Japanese model (that has been practiced by Brazil) where you have large producers and large converters

The inputs that we gave in KSP & NSP were mainly to the Indian model. That is small producer – small converter. The support that was given to the industry was not much. The planners at that time thought that we have to support the supply side and that is how all the support was given to the farmer. That was to strengthen the base. What has happened is there for you to see. Now, while looking back one gets the feeling; should we have supported the demand side, for that would have created a demand pull and perhaps resulted in better sericulture? All said and done, there is an absolute need that we change the Indian model of small producer & small converter. May not be totally towards the Chinese or Japanese side; but somewhere in between. For this I had proposed certain changes. There was a committee which had looked into these things and given a request to the Research Coordination Committee (RCC) of central Silk Board which was chaired by Prof. Chopra. He said that the suggestions of the committee should be put into practice at least by the leading states (Karnataka, Andhra Pradesh and Tamil Nadu). But I don’t think that has happened. We haven’t made course corrections. We tend to stay where we are. That is not good. We should adopt ourselves to the changes that are taking place. Everything is market driven today. We can’t say ‘I have a poor farmer, please buy’. I can’t go and ask people ‘buy Indian silk’. If the demand is met, if the quality is met, any silk is acceptable to a customer. Market doesn’t wait for you.

The focus of both NSP and KSP was popularisation of Bivoltine (BV) sericulture. India received a lot of technical support from abroad, especially from Japan and until recently Japanese stayed in India to ‘bivoltinise’ Indian sericulture. In this quest we have grossly over looked the strengths of local varieties of silk worm: the multivoltines and cross breeds etc. Given that the current percentage of diffusion of Bivoltine hybrid in the country is as low as around 10%, what is your assessment on India’s strategy on BV popularisation? How important is BV sericulture to India?
I don’t say, looking at the Indian sericulture, the situation is very conducive for bivoltine. Even in Karnataka we can practice only two crops of bivoltine out of 5 crops per year. Thus bivoltine is not favoured so much, climate wise.

We put in efforts since 1975 for developing Bivoltine sericulture in India. Beginner’s luck, you can say, we had very good results with bivoltine. But we have not been able to sustain it. As a person with long term association with silk industry, I would say that bivoltine is not for small scale farmer. That means bivoltine is not for our model of sericulture. Our farmers are poor. They don’t have the strength to absorb the technological advancements. They don’t have the capacity to invest. Under the project we supported them technically, financially and by way of extension. All these helped them to get the result which was very good. But the moment all these supports were withdrawn after the project it went back to square one.

We were quite successful in developing bivoltine for tropical conditions. The races we developed in Mysore were very good. There is no doubt about it. But the performance of Cross Breed (CB) was exceptionally good. Even today it is close to bivoltine and without much effort. Now the farmer realise why should he take all the trouble for bivoltine when there is no market for it. When he goes to the market, he s a loner, for very small quantities of bivoltine comes there. As a result there is not a demand for his product. Instead of that CB has give good results. Now the question is ‘was bivoltine developed for the improvement of CB?’ Honestly I feel: YES. Looking from both farmer’s and reeler’s side, yes it was. From our old multi-bivoltines like PM X NB4D2 etc., PM X CSR2 is a big jump. As that has happened I am quite happy even if bivoltine is not there. At least there has been a significant improvement in CB production which has helped the economics of the farmer. If cross breed is the answer, we can use BV for improvement of CB. So I still feel it is a big improvement and we should recognise that fact and then we should focus more on the growth of the industry in these lines rather than beating only BV

But the now celebrated Cross Breed (Kolar gold) has not been a research breakthrough. This has been a contribution from the graineurs.

Yes. This is the point. In research we had aimed at something and the fall out has been something else. We have succeeded in research. It is only the extension and transfer and sustenance of this knowledge at the farmer level (we have failed). I am not talking about a small number of farmers who are always under scrutiny and support. I am talking about farmers at large. But the entry of PM X CSR 2 and PM X CSR 4 has changed the whole situation.

Sericulture research has been a prerogative of Central Silk Board, as the government money for research goes to CSB. Has CSB been monopolising sericulture research in the country?

The fact is that apart from CSB research institutes other institutes were not developed to carry out bivoltine research. They didn’t have that kind of background. Where ever you talked about Bivoltine sericulture a scientist found elsewhere was from CSB or formerly from CSB. Two state institutes came up; one in Karnataka and the other in AP. Basically they were all meant for carrying out applied research. Sericulture research is basically applied. During the NSP period CSB invited proposals from umpteen numbers of universities. Some 80- 100 projects were approved and funds were made available. But their interest dried up after the project. They didn’t pursue it and try to get funding from elsewhere. Even today CSB supports research from universities but not to the extent one has been during NSP period. The bottom line there is the interest shown by people.

CSB dint monopolise any research. There was no need. Whatever facilities (equipments and man power) created in institutes and universities during NSP were all limited to the project period. Afterwards they haven’t really done much. The universities also don’t have any long term research plans. Research in our country has been influenced by the demands that have come up. There was this need to expend. That is we needed to produce more, reduce imports. This is the kind of situation that influenced our research. So we addressed productivity and quality. I agree that productivity and quality are not achieved at the final stage. One has to work from the beginning. But that kind of effort has been less. Again the interest of individuals also matter. Large number of scientists would like to delve more on applied areas rather than basic areas because they all feel that the results are quicker and they would be able to show something to the people. The number of people who have shown interest in basic research is less. It is not that we don’t have facilities for basic research in CSB. We do. Basic research is time consuming. You don’t get results over night. So we need people interested in these areas. The pressure of the market shouldn’t be coming to these people. Let the applied people take care of the market situation. I think the CSB would do well to create in each of its research institutes in Berhampore (West Bengal), Mysore (Karnataka) and Pampore (J&K); certain number of people and groups to go into basic research.

It was also thought during the NSP period (as I remember) to entrust universities with basic research. Universities were not expected to do applied research. But that thought didn’t materialise. There were wrong decisions made too. The Karnataka Sericulture Development Institute (KSSDI) later on became KSSRDI (Karnataka Sericulture Research and Development Institute). The research part was not there as it was conceived during the KSP period. The KSSDI was supposed to take out the output of Central Institute and ‘package’ for field requirements. But that responsibility was not taken by KSSDI. It became KSSRDI and became a competitor to Central Institute. That wasn’t required. Today there are problems. They are not able to get funds for salaries. A re-look is desirable and possible even today. KSSRDI could drop the ‘R’ and become a sequel to the research that is done at Mysore institute. Same holds good for APSSRDI of Andhra Pradesh. Their job is very important.

Indian silk reeling industry is visibly in peril. The farm sector of sericulture seems to have stolen the entire attention of policy makers, leaving silk reelers in hardship. Apparently the obsolete technologies prevailing in the reeling sector has made it incapable of absorbing whatever quantities of high quality bivoltine cocoons produced in the country. What has been happening to the reeling sector?

For the reeling industry to do well, quality of cocoons is primary. In raw silk production, 90-92% of cost of production is cocoon price (during normal times). Sometimes it can be even more than 100% where the reeler looses. He can only be compensated by selling by-products. Unless you have good quality cocoons it becomes impossible for the reeler to adopt new technologies. Central Silk Technological Research Institute (CSTRI) Bangalore developed multi-end reeling package and as many as 300 or more small units (which was the economic size at that point of time) were manufactured. They were all planted in a number of reeling areas. The quality of yarn came out of them was good. Only thing was the way the BV has not been able to influence the (cocoon) market, multi-end raw silk could not influence the raw silk market. The ‘influence factor’ comes with quantities in the market. Quantity influences the market. If BV has to influence, it has to be made available in very large quantities. Similarly multi-end silk has to be made available in very large quantities.

For the reeler, when he goes to the market, his buying ability restricted by the amount of money he has. None of these small units enjoy the kind of working capital support the bigger industries enjoy. We have worked on this also. There was a scheme to support these people. We went to banks, talked to them and some kind of support was made available. But still the reeler lacks the much needed large working capital base. Today it is once in 2-3 days the reeler has to go to the cocoon market. Buy cocoons, convert to silk, and sell silk and again go back to buy cocoon in 2-3 days. Whereas in the organised sector; it is at least a couple of months. A small reeler who is producing 10 kg silk per day would require at least 70 kg cocoons and if he has to survive well he needs to have a stock for 20-25 days. That means 1.5to 2 tonnes of good quality cocoons, which would cost at least Rupees 35 to 45 lakhs. Is this kind of money available to our reeler? That is why he is finding it difficult. Our own cocoons, for the quality they have, are the highest priced of the whole world. Nowhere in the world cocoons are as expensive as in India. That’s the reason why the reeler has not been able to change and he continues to work in a dirty situation with smoke, smell and all this.

This is where we have to look at the models of sericulture. There is a large number of people working in this sector. We can’t go on like this, talking about taking care of these many people. See, in the years to come frankly speaking, if you want to take care of these people as a state, you have to give them alternate areas to work. Take them out of this misery and keep only the required number of people in this activity to make it economical. And if something is not economical, I don’t think there is a need to practice it. If sericulture is not good for certain state why should they do it? Just because a sericulture department has been created, you don’t have to waste money. Sericulture is a culture. If it is a culture for a farmer in Kolar, because he has been doing it for generations and he knows what it is. You can’t take this culture and ask a person somewhere in another state who has not even seen a silkworm, into sericulture. That’s why we have failed. There are certain practices, very native. If I have to take it to Kerala, I have to see if it is acceptable to Keralites. The family and the neighbourhood should accept it. It is a culture by itself.

Is the silk weaving sector any better off? How well equipped is our weaving sector in catering to the needs (of high quality silk fabric) of the international silk market?

Indian textile industry is quite modern now, thanks to the Government of India interventions. More than 25,000 crores of Rupees has been infused into the industry and lot of modernisation has taken place. They are able to produce high quality yarn, a huge quantity of which is being exported. Formation of producer consortia has helped the situation by enabling the weavers to place bulk orders for raw material at competent prices. But the case has not been the same with silk weaving sector. It is too small a sector for taking to such changes. We have three sub sectors in silk weaving: handlooms, power looms and the highly organised shuttle-less loom sector. 95% of the silk fabrics produced is from the handlooms and power looms the bulk of which is coming from the handlooms. The conditions of the handloom weaver are not very good. He has no capacity to buy his raw material, which is silk yarn. He takes the yarn from a master weaver and converts it to fabric on wages. Thus he is only a converter or labourer, not an entrepreneur. The silk reeler is at least an entrepreneur. He is investing a few thousands of rupees every day. But a weaver doesn’t. So the handloom weaver is affected by the market conditions. And his situation is pretty bad. There is not enough demand for the handloom product. The reason is that he is not weaving fabric as per the requirements of the market. He knows to weave something which he continues to weave whether it sells or not. The handloom weaving industry is not reacting to market requirements.

Finally, what has been the contribution of Central Silk Technological Research Institute, to Indian silk Industry?

CSTRI has been a partner to bivoltine development, all along. Then we became the prime mover to improve quality of silk reeling. That’s where the multi end technology came into being. May be we dint succeed much in the reeling sector, because of the reasons I have already explained. But we succeeded in other areas like silk yarn dying. We successfully moved the dyers to new technology which has also influenced the market. Today the yarn dying industry has come of age. We developed a handloom and an electronic jacquard, which have diffused well in the industry. Another important development was computer aided designing coupled with a card cutting machine and automatic lacing of card. You see a large number of people using these technologies now. In Dharmavaram area itself as many as 150 computer aided design units are working. In the non-mulberry sector, the reeling and spinning machines we developed has gone to the filed in thousands, through supporting schemes. CSTRI is now recognised as a National Research Institute. It is also recognised as one of the Textile Research Associations by Ministry of Textiles, Government of India. We take up a lot of consultancy services for companies like Hindustan Lever, developing chemicals and evaluating their soaps and detergents. We have helped IFB, the washing machine people in developing a wash program for silks. We dint advocate continuous revolving of the drum. For silks, we said it should rock!

In conversation with Professor ECG. Sudarshan

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 25 Dec 2013 18:03:00 +0000

Interview by GK. Rajesh

Prof ECG. Sudarshan

Professor Ennackal Chandy George Sudarshan, better known as E.C.G. Sudarshan is one of the most eminent theoretical physicists of 20^th century. Born in Puthuppally, Kottayam district [Kerala] India, he cut a niche for himself in theoretical physics at a tender age. Sudarshan was just 26 when he first proposed the V-A theory of weak interactions as part of his PhD. The work was path breaking and still widely acclaimed. At 82 he continues to be active in research, teaching, writing and interacting with people. In spite of being nominated many times, he never received the Nobel Prize: a matter subject to controversy. Sheldon Lee Glashow, Abdus Salam and Steven Weinberg in 1979 and Roy J. Glauber in 2005 were awarded Nobel Prize for their work, built upon the theory of weak interactions originally developed by Sudarshan and Robert Marshak in 1957. Sudarshan doesn’t hide indignation:

“What I did for my PhD thesis in 1957 was probably one of the most important things in physics and they (the Nobel Foundation) should have nominated me at that time. If not then ten years later. No they didn’t. Instead they gave the prize to somebody who did something on top of it. I usually say if you want to award somebody you take the person who built the ground floor, not someone on the second and third floor. That is what they did. Glashow, Salam and Weinberg did the next step to what I did. Without the first step they couldn’t have done it”

The Nobel Prize is the greatest laurel in the academic world and is every scientist’s dream. But is it administered fairly? Professor Sudarshan is critical of the Nobel committee:

“I can assure you that it is not impartial. For example the prize given to Glauber, it is my prize. They gave it to him for things which I did. The prize is coveted because it is identified with excellence, and the majority of people who have got it, have gotten it for very good reasons. The very first prize was given to Rontgen, who discovered X-rays. At that time it was because of the fact that people recognised that X-rays were very important for medicine. But afterwards they gave it for all kinds of things. Like my friend Glauber got the prize for . . . I don’t know what; it can’t be because of the excellence of his work.”

The ‘wiki page’ on Nobel prize controversies tells us that Sudarshan’s indignation is quite reasonable. The Nobel foundation has a long history of denial of its coveted medal to deserving nominees. MK. Gandhi was nominated at least five times between 1937 and 1948. The Nobel Committee later acknowledged their mistake in 2006. Geir Lundestad, Secretary of Nobel Committee said "... the greatest omission in our 106 year history is undoubtedly that Mahatma Gandhi never received the Nobel Peace prize. Gandhi could do without the Nobel Peace prize, whether Nobel committee can do without Gandhi is the question..." Dmitry Mendeleyev for chemistry (the periodic table of elements fame), Leo Tolstoy, Henrik Ibsen, Emile Zola and Mark Twain for literature ... the list of eminent non-laureates is quite impressive. But Professor Sudarshan is still optimistic, as he has been awarded the prestigious Dirac Medal in 2010 which is held as a pre-curser to Nobel. Sudarshan muses:

“When I received the Dirac medal (that was the tenth year of the medal) many people had received it before me. Almost all of them received Nobel Prize subsequently. So this is an auspicious sign. I think it would be nice. I will enjoy it very much. But my life is not depended on it”

Independent India has no Nobel medal in science. The Prize won by sir C.V. Raman in 1930 has been India’s first and last. It took 38 years for yet another scientist of Indian origin, to qualify this distinction. Har Gobind Khurana (1968), S. Chandrasekhar (1983) and Venkitaraman Ramakrishnan (2009) followed Raman’s foot prints but built their research career in foreign lands affiliated to foreign universities. Hence the Nobel foundation doesn’t count these medals as India’s.
Professor Sudarshan lives in America. At heart he is a Malayalee who speaks in the local idiom, punctuated with Sanskrit and Malayalam quotes. While Raman built his science in India, Sudarshan left. Would it have been the same for him, had he stayed put? Or is it that we still lack facilities for doing decent science in India?

“Most of the people misunderstand the situation. It is not the facilities there. It is a place where scholars are there. If you are a scholar you want to be with other scholars, someone who appreciates what you do. Now it may be that one person goes abroad, other stays put and they are both doing very well. But generally what one is looking for is somebody who is scientifically competent. When people talk about things abroad, everybody talks about things abroad because it is good laboratories. I don’t need a laboratory. I just walk around with my hands in my pocket, occasionally take out a pencil and write something in a piece of paper. So it is not that. It is having people of the certain kind coming and the statement that are made saying that people are going abroad and that is affecting the country; that is not true, because if they do not go abroad they will create problems. You know the big scientific establishments are always sulky and the people sitting at the top are like kings of old days. But science is done by some people who are doing things and you want another person who is a scientist who can challenge you. If he agrees that what you say is good, you feel good because he will not say it unless he has to. So it is that which is attracting people.”

Facilities and people apart, is India’s scientific environment conducive to productive research? The World Bank’s data base indicates that during 2010 the number of patents filed by Indian scientists from outside India was four times of those filed from India. China and Russia have a different story to tell. 75% of China’s and 67% of Russia’s patent applications were filed from within those countries. This is indicative, not only of the high levels of self-sufficiency these countries have attained in scientific research, but also of the fact that the number of scientists leaving these countries for research is much lesser compared to India, Brazil and S. Africa. Professor Sudarshan is critical about our scientific environment.

“When plants grow, they grow. You like roses to grow and thorns not to grow. But then they come together. So you cannot say that science is doing all the right things. But the number of scientists today compared with when we were students is amazing. There were no scientists those days. There were some names people mentioned but there were no scientists. The people who taught us were people who learnt a little more and sometimes did not know very much more. But now there are scientists everywhere. The amount of scientific research that is being carried out now and the level at which it is being carried out is very high. But could it be better? Of course it could be. Whenever you produce things according to a government plan or something like that rather than organic growth, then there is always a case of overbuilding. There are big national laboratories which do not do anything. There is a joke that somebody went to NPL, National Physical Laboratory to investigate the research institution.

‘How is that place?’ Someone asked

‘The place is dead’

‘But isn’t there any stink about it?’

‘No no, it is air conditioned’

With Dr. Bhamathy Sudarshan

NPL did not do a worthwhile thing at all for first few decades of its existence. Nevertheless British had a NPL and we too wanted to have one; same name. But at that time the universities were not given any money. No research in the universities. By the time you get your masters degree that is the end of the thing. There is no more. The other people who taught us were also having master’s degree only. Now it s very different because there are so many people who have PhD; not only PhD but they continue to do research. So the level of scientific research has increased but it is not clear that its product is always good. In India the pace of research is going up except that this is a very awkward growth. It is like a tumour; that some institutions and some groups of people have so much money and they have no problem about looking for God’s particles and such nonsense. But there is no money for the universities.”

At 82, despite difficulty in walking, Professor Sudarshan is as energetic as a school boy, radiating knowledge and charm all around. Speaking in his deep, gritty voice often transgressing the physical boundaries of science into philosophy, liberally quoting from Vedas, Upanishads and Bible, he cuts a sage like and enigmatic personality. You are easily drawn to him and get totally won over. He says “. . . when I was young I was impatient with fools. Now that I have grown old, I can speak to any one for any length of time . . .” and laughs a hearty laughter. In this man the whole country pins its hope for yet another Nobel medal.

Also see by the author: Science Reporter Science India

SeriCha - Organically produced mulberry tea: background, mechanism of action and clinical data

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Mon, 16 Dec 2013 07:35:00 +0000

Dr. Radhakrishna P M, Ph.D, Director-Innovation, Healthline Private Limited, Bangalore

Sericare is division of Healthline Private Limited based in Bangalore, India, working in the area of developing and marketing products for Sericulture farming since the year 2000. From 2010 onwards it has diversified into development of value added products from in-put, out-put and co-products of sericulture for various human use and applications in the area of food, cosmetics and therapeutics. While the mulberry farm from where leaves are sourced for SeriCha production is organically certified, all the manufacturing plants producing various innovative products of the company have GMP certificates along with necessary Food and Drugs administration clearances. SeriCha, is a product of Sericare Division of Healthline Private Limited. It is specifically processed mulberry leaf grown in an organic farm near Bangalore with no residues of pesticides, heavy metals and other contaminants. The processing of leaf is done in a “Good Manufacturing Practices” certified facility. The product is placed in the market in the form of easy to use dip bags.

Contact the team at: sericare.research@gmail.com

Mulberry is a tree belonging to the genus Morus of the family Moraceae. It is distributed over a wide area of tropical, subtropical, and temperate zones in Asia, Europe, North America, South America, and Africa. There are at least 24 species of mulberry with more than 100 known cultivars. Historically the trees have been planted for sericulture in east, central and southern Asia.

According to Shennong’s Materia Medica, a Chinese medicinal plant book, mulberry plant’s origin is believed to be the first century BC. In that book, mulberry leaves were described as useful for relieving cough, high blood pressure and palsy. When dried in the Sun and brewed the resulting tea was known by the name “immortal mountain wizard tea”. Mulberry has been used in Chinese medicine since 659 AD. The virtues of mulberry have been extolled in “Book of Songs” written in 1000 BC. On the basis of folklore remedies, the leaves have been used as a Chinese herbal tea, especially for diabetes. In the “Compendium of Materia Medica”, written in the late 1500s, Li Si Zhin recommends leaves of white mulberry for treatment of diabetes and obesity.

Silk making reached Japan by the fourth century AD, so Japan has a long history with the mulberry plant as well. In fact, kuwacha (mulberry leaf tea) consumption is older than tea for the Japanese, considering that tea seeds first came to Japan during the Heian period (794-1185 AD). It has been traditionally drunk in Japan for many years because of its health benefits.

In the modern era, health benefits from mulberry products have been verified scientifically, with mulberry leaves shown to have potent α-glucosidase inhibitory activity mainly because of presence of azasugars. Azasugar,1-Deoxynojirimycin( DNJ) is a naturally occurring alkaloid from the mulberry tree, which was first isolated by Yagi et al. in 1976. Chemically DNJ is a glucose analogue with an NH group substituting the oxygen atom of the pyranose ring. In recent years, DNJ has attracted considerable interest because of its effective and specific inhibition of various carbohydrate-degrading enzymes involved in a wide range of important biological processes, such as intestinal digestion, hepatic glycogen breakdown, lysosomal catabolism of glycoconjugates, and maturation of the sugar chains in glycoproteins.

Modification of carbohydrate metabolism by dietary foods and drugs may have therapeutic value. Recently, several animal and human studies have supported the administration of mulberry leaf or extract to suppress the postprandial increase of blood glucose levels. After oral administration, DNJ is absorbed into plasma in intact form from the alimentary tract and reaches a maximum plasma concentration at 30 min before quickly diminishing from urinary excretion. α-glucosidase, located in the brush-border surface membranes of intestinal cells, is considered to be the most important enzyme in digestion of starch and other carbohydrates. DNJ binds to the active center of α-glucosidase and is a potent inhibitor of this enzyme in the small intestine resulting in a decrease of glucose absorption and therefore decrease in blood sugar levels. Because of its moderate activity in vivo mulberry leaf tea or extract is considered as a functional food instead of a drug.

There are several international studies on mulberry leaves and extract. A study conducted by Kimura on humans with mulberry leaves showed a suppressive effect on the postprandial increase in blood glucose It was shown that DNJ prevented diet-induced obesity through an increase in adiponectin in mice. Oral and intravenous glucose tolerance tests and labeled 13C6-glucose uptake assays suggested that DNJ inhibited intestinal glucose absorption. Studies also showed that DNJ down-regulated intestinal SGLT1, Na+/K+-ATP and GLUT2 mRA and protein expression.Nagendra and Shiva conducted a study on 75 diabetic patients at Mahalakshmi Clinic, Mysore using mulberry tea, and recorded significant reduction specifically in postprandial blood sugar levels in both men and women in various age groups. The mulberry tea was made by using 2.5g of dry mulberry leaf suspended in 75ml boiling water for two minutes. The tea was given twice daily just before morning breakfast and dinner. The result shows that mulberry leaf extract has direct effect on reducing diabetes.

Average post prandial blood sugar level in different age groups

Recently Banu and coworkers from Sri Jayadeva Institute of Cardiovascular Science and Research, Bangalore studied effect of mulberry tea on dietary reduction of postprandial hyperglycemia seen in metabolic syndrome and type-2 diabetes.

The study was designed with follow-up diabetic patients, 20 of them as controls who were given plain tea and 28 of them were given mulberry tea containing DNJ to measure effect based on FBS and PPBS. Fasting blood glucose sample was collected, followed by standard breakfast and one cup of 70ml tea with 1 teaspoon of sugar. The postprandial blood glucose was measured again at 90minutes in all 48 patients.

Mulberry tea was found to suppresses postprandial rise of blood glucose levels with a very significance level of

with very large effect size.

SeriCha, a product of Sericare Division of Healthline Private Limited*, is specifically processed mulberry leaf grown in an organic farm near Bangalore with no residues of pesticides, heavy metals and other contaminants. The processing of leaf is done in a “Good Manufacturing Practices” certified facility. The product is placed in the market in the form of easy to use dip bags.

A clinical investigation was undertaken by Neeta Deshpande of Belgaum diabetic centre of Belgaum which is a randomized, single blind, placebo controlled, parallel group study of comparing SeriCha (SC) with commercially available green tea (GT). The study population consisted of type 2 diabetic patients (n-30) with duration of less than five years. The tea prepared as per the manufacturer’s recommendation was offered to subjects three times a day and study was continued for 8 weeks.

At entry into the study, a detailed medical history was obtained as also complete physical examination, vitals, and anthropometric measurements. Baseline HbA1c, lipids and blood sugars were obtained. Subjects were followed up every fortnight for 2 months and evaluated for any adverse events, blood sugar levels, vitals, etc. Compliance to treatment was checked and ensured at every follow-up visit. At the last visit, anthropometry, vitals and lab parameters such as HbA1c, lipids and blood sugars were evaluated again. Other safety parameters such as liver enzymes and creatinine were monitored.

All the results presented are a comparison of effects from baseline to end of treatment (EOT) within each group.

FBS reduction: 18.9 % in SC group (p 0.0009) Vs 7.01% in GT group (p 0.09)
PPBS reduction: 18.1% in SC group (p 0.024) and 18.2% in GT group (p 0.023)
Percentage of subjects with FBS reduction: 92% in SC group had a mean FBS reduction of 56.4 %, ie, 29.4 mg%, from baseline to EOT (p 0.003) whereas 70 % subjects in GT group had 58.8 % reduction (28.1 mg %) (p 0.009).
Percentage of subjects with PPBS reduction: 84.6 % in SC group had a mean FBS reduction of 132.5 %, ie, 64.7 mg%, from baseline to EOT (p 0.0005) whereas 70 % subjects in GT group had 115 % reduction (49.8 mg %) (p 0.0001).
HbA1c reduction: In the SC group the reduction from baseline to EOT was 0.5 % (p 0.028) whereas it was 0.1 % in the GT group (p 0.22).
HDL: No statistically significant change in either group from baseline to EOT.
LDL: Modestly significant decrease in GT group and no change in SC group.
Total cholesterol: Reduction in both groups, but slightly more significant in GT group.
Triglycerides: No change in either group.
SGOT: Significant reduction (p 0.02) in SC group compared to GT group (0.62).
SGPT: Reduction in both groups, but not significant.
Serum creatinine: No change in either group.
Systolic BP: Very modest reduction in SC group, but not significant.
Diastolic BP: Reduction in both groups, but not significant.
Anthropometry: No change in either group with respect to weight/BMI or body fat percent.
No significant adverse events were observed in both group and none that could be related to either SC or GT. All patients completed the study with good compliance.

Overall it can be concluded that tea/extract made out of mulberry leaf has significant effect both on fasting blood sugar and postprandial blood sugar in case of type II diabetic patients and SeriCha, which is processed through good manufacturing practices and obtained from mulberry plants cultivated organically along with effectiveness assures safety to the consumers.

FYT-99/G4, an early sprouting Morus alba genotype for north western India

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Thu, 31 Oct 2013 06:47:00 +0000

R.K.Pandey

Regional Sericultural Research Station, Miransahib, Jammu 181101

[Previous stories written by RK. Pandey can be accessed HERE and HERE]

Abstract

Fig.1 Stages of bud break after winter dormancy

In north western sub Himalayan states such as Jammu and Kashmir, Punjab, and Himachal Pradesh, early sprouting mulberry genotype is a boon for on time spring crop rearing because any delay in bivoltine rearing in spring season adversely affects cocoon production. Among the five newly evolved genotypes, FYT-99/G4 was found to be an early sprouter. FYT-99/G4 sprouted first of all after 33 days of winter pruning. Secondly, Vishala sprouted 44 days after pruning. The genotypes, S-1635 and C-2038 sprouted together after 49 days. Suvarna-2 sprouted lastly 52 days after winter pruning. The differences were significant except between C-2038 and S1635. However, the differences in sprouting duration were not significant after July pruning in monsoon season, where, FYT-99/G4 sprouted within 11days of pruning, Vishala and S-1635 sprouted within 12 days. The genotype C-2038 sprouted within 14 days after pruning and Suvarna-2 sprouted within 15 days in Monsoon period.

In spring season, which is the main period for bivoltine silkworm rearing in North western Indian states, due to the early sprouting character, FYT-99/G4 is useful for feeding silkworms at Chawki Rearing Centres to synchronize adult age rearing with leaf maturity in the field on already existing mulberry trees, which usually sprout late. By on time distribution of chawki silkworms, the cocoon yield in the field improves considerably.

Introduction

With the onset of spring season with long photoperiodic conditions, the mulberry, which sprouts first of all, is called early sprouting variety. Such early sprouter is identified as early sprouting genotype. Early sprouters are preferred for feeding silkworms in the spring season, because they give sufficient quantity of leaves on time in March. With rise in temperature in April, the season becomes unfavorable for silkworm rearing. So far, only the Morus alba genotype ,S146 and S1635 are available for the north western sub Himalayan, which sprout first of all in January itself as a result, there is great demand of these by the farmers of the region, because other genotypes sprout in the first week of March. Koul (2006) examined twenty varieties of mulberry in Jammu and demarcated two groups. One, early sprouting tropical varieties, Chak Majra, Tr-10, Sujanpur and C763. The second group includes late sprouting temperate varieties, Ichinose, Rokokayoso, Enshutaka and Goshoerami. While tropical varieties sprouted in 3^rd week of January in Jammu region, the temperate varieties sprouted in the first week of April under the sub tropical environment of Jammu.

In the present work, the sprouting behavior of five newly developed genotypes of the Sericultural Research Institutes of South and North East were observed from early sprouting point of view as per the need of north western Sub tropical India.

Material & Methods

The experiment was conducted at the Regional Sericultural Research Station, Miransahib, Jammu. The area is sub –tropical, situated on the geographical coordinates of 31^o14’29” N, 77^o2’12”E. It has an average elevation of 327m (1073ft) above mean sea level. The soil of the site is sandy loam in texture, neutral to acidic in reaction (6.5). The genotypes were imported from different Research Institutes under an All India Coordinated Experimental Mulberry trial ( TableI)

Table I : Genotypes evaluated at Jammu

Preparation of saplings

The hard wood stem cuttings of all the genotypes were prepared choosing the middle part of the juvenile twigs. Each cutting measured about 2.5 cm in diameter and 15cm in length possessing 3-4 active vegetative buds. Due care was taken to avoid damages to the buds and cut ends while preparing the cuttings. The cuttings were planted in the freshly prepared nursery containing well dried pulverized garden soil,sand and well decomposed farm yard manure in the proportion 1:1:1 and maintained with consistent care in July( Jolly and Dandin,1986).

Raising of plantation

Six months old saplings were planted in the pits under 90x90 cm (plant to plant) in random block design with six replications.

Block size (Length x Breadth) : 40.5m x 8.1m =325.05 sq .m.

Net Experimental area /plot : 6.3m x 6.3 m=39.69 sq.m.

Total experimental area /plot : 8.1m x 8.1m=65.61 sq.m.

No. of experimental plants /plot: 7x7= 49

Total number of plants /plot: 81

Pruning

The saplings were pruned at bottom level nearly 15 cm from the ground ,immediately after sprouting of the newly planted saplings to make bush type canopy. Subsequently, a pruning schedule was followed. where annually middle pruning was done 100 cm from ground in mid December (winter) and 30 cm from ground in July(Monsoon). Annually Farm yard manure was applied @20MT/ha in two split doses. NPK was applied @75:75:75 kg/ha in two split doses, besides routine cultural operations.

Fig.2. Sprouted mulberry,Morus alba, Genotype FYT-99/G4

Data collection

Data on sprouting behavior of different genotypes was recorded after one year of plantation by adopting methods of analysis of variance appropriate to the design of the experiment (Sundaraj et.al.1972).

Results and Discussion

The early sprouting Genotype

It can be seen from Table II, that among the five newly evolved genotypes, FYT-99/G4 was an early sprouter. FYT-99/G4 sprouted first of all in January after 33 days of winter pruning on December, 17. Secondly, Vishala sprouted 44 days after pruning. The genotypes, S-1635 and C-2038 sprouted together after 49 days. Suvarna-2 sprouted lastly 52 days after winter pruning. The differences were significant except between C-2038 and S1635.

The differences in sprouting duration were not significant in monsoon period after July pruning (Table II). In monsoon season, FYT-99/G4 sprouted within 11 days after pruning, whereas Vishala and S-1635 sprouted after 12 days. The genotype C-2038 sprouted 14 days after pruning and Suvarna-2 sprouted lastly after 15 days.

Table II: Asynchronous sprouting of the mulberry genotypes

At the Regional Sericultural Research Station, Miransahib, Jammu, number of accessions are maintained under germplasm including the varieties that were reported by Koul (2006) as early sprouter, such as Chak Majra, Tr-10, Sujanpur and C763. Chak Majra is synonym of the variety S146, which is widely cultivated in North West sub Himalayan India due to early sprouting nature. Among the five new genotypes evaluated in the present work, it was observed that FYT-99/G4, S1635 C-2038 sprouted earlier than the ruling variety S146, after winter dormancy.

Effect of Rainfall and Temperature

Soil moisture plays an important role in leaf bud break after winter dormancy. During the present investigation, at the time of winter pruning in December, 69.2 mm rainfall occurred. Thereafter, 41.4mm, 168.2mm and 34.8 mm rainfall occurred in January, February and March, respectively. To survive the coldest part of the winter, mulberry buds are isolated from the mulberry’s vascular system (water-conducting xylem and nutrient-conducting phloem) and start losing moisture from autumn season with decline in ambient relative humidity. It needs both increasing temperature and tissue wetting for bud break and shoot emergence to occur with onset of spring season. The results of this study reveal that the varieties differ in their requirement of moisture and temperature for leaf sprouting and growth.

The average maximum temperature declined upto19.2^oC in December from 25.8^oC of November. Similarly, the average minimum temperature declined upto 5.8^oC in December from 9.4^oC in November. Winter continued in January with similar low temperature. The temperature started rising in February, when the average maximum temperature was 19.2^oc and minimum 9.1^oC. Accordingly, the early sprouting genotypes such as FYT-99/G4, showed bud break in February with rise in temperature, whereas other varieties took a few more days.

Effect of Photoperiod

Photoperiod exerts a considerable influence in the leaf bud break of mulberry. An optimum period of 11 hours illumination is desirable. The day length was observed to increase from February in Jammu, which coincides with leaf bud break in early sprouting genotypes of mulberry. The important role of short photoperiods in the autumn as the dormancy-inducing signal has been amply demonstrated and documented in a wide range of woody plants (Kramer, 1936; Downs and Borthwick, 1956).The results show that photoperiod requirement of different varieties may differ as a result, the genotype such as FYT-99/G4, might have required less duration of light to sprout in comparison with other genotypes.

The early sprouting genotype such as, FYT-99/G4, S1635, and S146 are useful for feeding chawki silkworms at Chawki Rearing Centres to synchronize adult age rearing with leaf maturity in the field on already existing mulberry trees, which usually sprout late. By on time distribution of chawki silkworms, the cocoon yield in the field improves considerably.

References

Downs R.J and Borthwick H.A. (1956) Effect of photoperiod on growth of trees. Botanical Gazette. , 117:310–326.

Jolly, M.S. and Dandin, S.B.(1986) Collection, conservation and evaluation of mulberry(Morus spp.) germplasm..CSR&TI, Mysore, India, 43.

Koul. A.(2006) Mulberry leaf sprouting as an indicator of spring rearing. Journal of Research,SKUAST - J, 5, 2, 173-178.

Kramer, P.J. (1936) Effects of variation in length of day on growth and dormancy of trees. Plant Physiology, 11:127–137.

Sundaraj,G.L.,Nagaraju,M.N.,Venkataramu and Jaganath (1972) Design and analysis of field experiments.UAS,Misc,Series No.22,Bangalore,India,424-440.

SNAIL INFESTATION ON MULBERRY (MORUS ALBA) IN HIGH WATER TABLE AREA OF KATHUA (JAMMU AND KASHMIR) DURING MONSOON SEASON

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Thu, 24 Oct 2013 07:00:00 +0000

R.K.PANDEY and A. DHAR

Regional Sericultural Research Station, Miran Sahib, Jammu, E mail: pandeyjammu@gmail.com

[A previous story written by RK. Pandey can be accessed HERE]

Snail is recognized by the Global Invasive Species Programme (GISP), as one of the 84 100 most destructive biological invasions in the world. This herbivore has a voracious appetite and is known to feed on over 500 species of plants (Simberloof, 2003). Apart from this, snail poses a potential health risk to humans, as some of its specimens are associated with an intermediate host of a nematode parasite Angiostrongylus Cantonensis, which is commonly known as the rat lung worm (Civeyrel and Simberloff, 1996; Carvalho et al 2003). This vector has the potential to cause eosinophilic meningoencephalitis and brain damage in humans (Upatham et al 1988). From India, Thangavelu and Singh (1983) reported giant African snail as a serious pest of mulberry from north eastern region. Shree and Kumar (2002) reported that snail infestation reduced moisture, proteins and starch content of mulberry leaves, but increased the content of phenols. Recently, Achatina fulica caused havoc in mulberry gardens of Ramanagram district especially in Kanakpura area (Kumar et.al.2011, Sreenivas et al., 2011). Gopinath et.al (2013) has reported this snail infesting mulberry gardens in Tamil Nadu. However, this is the first report on the occurrence of Zachrysia provisoria (Pfeiffer 1855) in mulberry garden of Kathua in Jammu and Kashmir, particularly in area, where depth to water levels prevail less than 2meter during monsoon period between July and September.

A close view of Zachrysia provisoria

Kathua lies at the southern most end of the state and is located between 34^o16’00” TO 32^o55’00” North Latitude and between 75^o06’ to 75^o54’ East Longitude. Various parts of the district experiences wide range of climate from sub-tropical to temperate and even Alpine in high regions of Bani. Due to altitudinal variations the plain areas of Kathua invariably differs in the temperatures from the hilly (Billawar and Bani) areas of the district. In Kathua, summer temperature rises as high as 48^oC and winter temperature falls as low as 3^oC in the plain. The district experiences rainfall during monsoon season and in winter and early summer. The average annual rainfall in the district is 1672 mm. About 85% of the total rainfall is received during monsoon season between July and September and rest occurs during December to February. Depth to water levels prevail less than 2m in and around Kathua plain area during the monsoon period, where the mulberry garden was established for silkworm rearing by the Research Extension Centre, Regional Sericultural Research Station, Miransahib,Jammu. About one year old saplings of an improved early sprouting Morus alba variety S146 were planted in the year 2001 under 3x3 feet spacing and bush type canopy was maintained by annual ground level pruning in monsoon period. The snail infestation was noticed during the annual pruning operation in July 2002. Thereafter, observations were recorded for three continuous years up to 2005, regarding its seasonal infestation on mulberry. The snail Zachrysia provisoria was identified based on the basis of distinct morphology. In order to ascertain the density of snail in the mulberry garden at Kathua, a 10 metre transect- with 2 x 2 m quadrats - (each transect had 5 quadrats) was established. Subsequent transects were established every 10 metres. This process was repeated 8 times, giving the sampled area a total of 40 quadrats (N=40) for the garden. All individuals of snail that were in each quadrat were then counted, the weather condition was also recorded.

Z. provisoria was very active during rainy season from July to September in Kathua. Heavy downpour for two to three days resulted in its outbreak. This snail spends most of his life time in dormant condition, especially during unfavorable climatic conditions. The shell of Z. provisoria is medium-sized (25 to 30 mm width), and globose in shape. There are four to five rapidly expanding whorls, with the body whorl increasing in size more than those of the spire. There is no umbilicus. The shell is sculptured with fairly regular, strong, retroactively curved axial ribs, and the body whorl descends greatly near aperture. The base is swollen, fairly smooth and shining. The apertural lip is thickened within, slightly reflected. There is a prominent protuberance or buttress on basal lip near columellar insertion. It lives among leaf litter and among mulberry plants. Z. provisoria is a voracious herbivore and causes significant damage to mulberry. They were found very actively moving in marshy mulberry fields after dusk, eating voraciously mulberry leaves and even bark damaging epidermis and even vascular bundles, leading to weakening of stems. The shoot becomes fragile yellowish and collapse. The leaves lose their nutritive values and defoliate, causing considerable damage to mulberry plants in general and chawki garden in particular. The density of the snail per square meter was found to be 1.2 at Kathua in the rainy season. The snail was found to be nocturnal feeder but remained active during the day in cloudy rainy weather. In dry weather, it burrowed into the ground or crawled under shelter where it remained for several weeks or months. However, a survey of the district Kathua revealed that this snail was confined in areas where water table was near to the surface. No such snail infestation was recorded in Kandi plains and in higher hilly areas of Kathua district, where the ground water depth is more than 30 m.

Snail (Zachrysia provisoria) density in monsoon period in Kathua district

The snail may be of economic importance as a medicinal and nutritional protein source (Santos Carvalhoetal, 2003) but snail remains a serious agri-hortcultural pest throughout the Indo Pacific Islands (Raut, 1982). The snail presents possible public health hazards with regard to the spread of disease such as angiostrongylosis and eosinophilic meningoencephalitis due to its important role as a host in the life cycle of Angiostrongylus cantensis (CAB2003). Plant diseases such as black pod disease caused by Phytophthora palmivora are also spread through the faeces of the snail (Raut and Barker, 2002). Spray of salt water solution (4kg of salt in 10 liters’ of water) is found quiet effective in controlling snail. This study has indicated that Z. provisoria has successfully manifested and established itself within Kathua ecological community.

CONCLUSION

A terrestrial snail Zachrysia provisoria ( Pfeiffer 1855) was found infesting Morus alba in high water table area, where depth to water levels prevail less than 2meter, of Kathua between July and September during monsoon period. However, no snail was found in Kandi and hill area of Kathua, where the ground water depth is more than 30 meters. This is the first report of snail pest on mulberry, which is cultivated in Jammu and Kashmir for Sericulture.

REFERENCE

CAB. 2003. Crop protection compendium: global module. Commonwealth Agricultural Bureau International, Wallingford, UK.

Carvalho, O.S., Teles, H.M.S., Mota, E.M., Mendonca, C. L. G., and Lenzi , H.L. 2003. Potentiality of Achatina Fulica Bowdich, 1822 (Mollusca: Gastropoda) as intermediate host of Angiostrongylus costaricensis moreira and cespedes. Brazilian Society for tropical Medicine. 36: 743-745

Civeyrel, L. and Simberloff, D. 1996. A tale of two snails: is the cure worse than the disease? Biodiversity and Conservation 5: 1231-1252.

Gopinath, O.K., Rajakumar, S.Balkrishna, R. and Qadri, S.M.H. 2013. Giant African Snail noticed infesting mulberry gardens in Tamil Nadu. Indian Silk,3(10&11):12.

Kumar, N., Shekhar, M.A. and Qadri, S. M. H. 2011. Giant African nail in Mulberry: Physiology and management. Indian Silk, 1 (12): 4-5.

Sreenivas, B. T., Shekhar, M. A., Anantharaman, K. V. and Kumar, N. 2011. Giant African Snail infestation in Hosakote too!. Indian Silk, 1 (12): 9.

Raut, S. K. 1982. The extent of damage inflicted by Achatina fulica Bowdich to agrihorticulture economic plants. Zoological Society of India Journal 34: 7-12.

Raut, S. K., and G. M. Barker. 2002. Achatina fulica Bowdich and Other Achatinidae as Pests in Tropical Agriculture., pp. 55-114. In G. M. Barker [ed.], Molluscs as Crop Pests. CABI Publishing, Hamilton, New Zealand.

Santos Carvalho, O. d., H. M. S. Teles, E. M. Mota, C. Lafetá, G. F. d. Mendonça, and H. L. Lenzi. 2003. Potentiality of Achatina fulica Bowdich, (Mollusca:Gastropoda) as intermediate host of the Angiostrongylus costaricensis Morera &Céspedes . Revista de Sociedade Brasileira de Medicina Tropical 36: 743-745.

Shree,M.P. and Kumar,K.R. 2002. Effect of gaint African snail-Achatina fulica Bowdich infestation on the nutritional quality of mulberry (Morussp.) leaves. Bulletin of Indian Academy of Sericulture 6 (1): 50-56

Simberloff, D. 2003. How much information on population biology is needed to manage introduced species? Conservation Biology 17 (1) 83-92

Shree,M.P. and Kumar,K.R.2002. Effect of gaint African snail-Achatina fulica Bowdich infestation on the nutritional quality of mulberry (Morussp.) leaves. Bulletin of Indian Academy of Sericulture 6 (1): 50-56

Thangavelu K and Singh K 1983. Giant African Snail Achatina Fulica Bowdich (Pulmonata: Gastropod) as a serious pest of Mulberry from north-eastern region. Indian Journal of Agriculture 602 Science. 53 (9): 871-2

Upatham, E.S., Kruatrachue, M., and Baidikul, V. 1998. Cultivation of the Giant African Snail, 609 Achatina fulica. Scientific Society Journal of Thailand. 14:25-40

Protein markers as a potential tool for biochemical characterization of silkworm genetic resources

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Thu, 26 Sep 2013 08:11:00 +0000

K. Ashok Kumar*, P. Somasundaram, G.K. Rajesh, R. Chandrasekar, N. Balachandran and V. Sivaprasad

The 1^st, 2^nd, 4^th, 5^th and 6^th authors are with Central Silk Board (CSGRC, Hosur) India. The 3^rd author is with Council for Nature Conservation and Environmental Protection (CONCEPT), India

Introduction

The silkworm Bombyx mori L. is one of the earliest examples of insect domestication and commercial exploitation. The insect is believed to be first identified and put to use by the Chinese nearly 4500 years ago. Since then the species has been subject to severe selective pressure, targeting improved quantitative traits (with reference to silk). As a result the cocoon shell weight has increased manifold while the insect has lost many of its defensive features that once helped it survive in the wild fighting whether, natural enemies and diseases. The fact that one of its closest ancestors namely Bombyx mandarina still lives in the wild enables us comparison which testifies to the above statements. While the progress so far made is quite impressive (in human angle), it is widely perceived that the insect leaves much to be desired in terms of quantitative output and tolerance to adverse environment, pests and diseases. Thus location specific hybridization programs are in vogue towards evolving productive hybrids which are not only tolerant to specific micro climates and pathogenic flora but also adaptable to resource saving techniques such as artificial diet. The process has lead to creation of silkworm germplasms in many countries offering a wide variety of genetic resources to select from. However, selection of parental breeds has become quite a challenging task, given such a vast and varied collection of geographic races, evolved breeds, transgenic lines, mutant stocks etc. This article sums up a series of studies conducted at the Central Germplasm Resources Centre (CSGRC) Hosur, India and proposes the application of protein markers for characterization of silkworm genetic resources to identify duplicate genotypes and to find out intra and inter racial variations.

Experimental material

This paper summarises a few laboratory screening studies conducted on 28 silkworm accessions (14 multivoltine races and 14 bivoltine races) maintained at Central Sericultural Germplasm Resource Centre (CSGRC), Hosur Tamil Nadu, India (latitude 12°45’N and longitude 77°5’E, altitude 942M AMSL). The center maintains a total of 421 accessions: 71 multivoltines and 350 bivoltines (Thangavelu et al., 1997 and 2000). The details of the races used for study; such as geographical origin, and cluster groups based on genetic distances are furnished in tables 1-3

Table 1. Details of geographical origin and class of 28 silkworm accessions

Table 2. Cluster groups based on genetic distances in 14 MV races

Table 3. Cluster groups based on genetic distances in 14 BV races

Biochemical markers for characterization

Identification of suitable biochemical markers is a pre-requisite for the successful implementation of Marker Assisted Selection (MAS), which is being used in the field of animal breeding work (Patnaik and Datta, 995). Allozyme/isozyme markers are the most widely used protein markers and are commonly separated on starch, polyacrylamide or cellulose acetate media and stained using enzyme specific reaction mixtures.

Allozymes of a given enzyme are the products of different alleles at a specific locus. Diploid (2n) organisms can be homozygous or heterozygous having two copies of the same allele or heterozygous having different alleles coding for charge size variants of the same functional enzyme, hence the term Allozymes. Allelic variations through isozyme studies are known to reflect the genetic diversity (Parkash et al., 1992). Recently, haemolymph proteins attracted a great deal of attention as a biochemical model system (Wyatt and Pan,1978; Law and Wells,1989). The main haemolymph proteins, lipophorin(LP), storage protein (SP) and vitellogenin (Vg) are common in insects and have special function for development, metamorphosis and reproduction. Storage proteins are the major reservoirs for amino acids that are utilized for cuticular proteins and for adult development (Levenbook,1985). These biochemical markers are extensively used to describe the genetic constitution of an individual that can also be used to determine the genetic diversity existing in a population. Munn and Greville (1969) used ultra centrifugation data for quantification of storage protein-1 and Kinnear and Thomson (1975) relied on visual inspection of stained PAGE bands for gross appraisal of the various storage proteins, while Sekaris and Scheller (1977) estimated storage protein–1 by densitometry of SDS-PAGE gels and storage protein-2 by densitometry in silkworm races( Somasundaram et al.,2004)

Heat shock is known to alter the enzyme activity in different animal systems. A certain fraction of an isozyme may disclose temperature tolerance. Wu et al (1993) reported that the thermo tolerance varies with strains and is positively related to the activity of a heat stable esterase (Hs-EST) analysed in larval body or midgut. This enzyme activity can be adopted as an indicator for the silkworm thermo tolerance. The stability of an enzyme under higher temperature may have a protective role in the adverse environment.

The information generated from biochemical marker studies on silkworm genetic resources through allozyme/isozyme markers, storage proteins, and heat stable esterase enzymes activity would help in identifying germplasm for hardiness in silkworm, genetic variations among and within races, identification of duplicates and thermo tolerance among silkworm germplasm stocks.

Biochemical markers for hardiness

Amylase enzyme as a biochemical marker was studied in silkworm genetic resources for its effective usage as surrogate breeding parameter to correlate amylase activity with economic traits. This study was aimed at identification of suitable biochemical markers for the successful implementation of Marker Assisted Selection (MAS) which being used in other fields of breeding (Datta, 1998, Jayaswal et al., 2000). Out of a number of biochemical parameters viz., digestive amylase, invertase, protease, alkaline phosphatase and haemolymph trehalose, only the digestive amylase has a significant positive correlation with survival on one hand and negative correlation with weight of larvae, cocoon and shell on the other (Chatterjee et al., 1992). The genetic divergence in term of activity as well as isozyme, polymorphism coupled with its role in better digestibility and survivability indicates the prospect of using amylase as a marker in silkworm breeding. It is reported that multivoltine races contain dominant amylase gene (Ae+) with four to five band polymorphism responsible for inducing hardiness in multitovltine races. This gene (Ae+) recessive in temperate races with no amylase isozyme band (Null type) may be responsible for less tolerance to climatic fluctuations. Thus the dominant (Ae+) gene can be transferred to temperate races through a suitable vector for developing hardy bivoltine races. Similarly haemolymph amylase isozyme studies conducted so far showed variability in its activity in different silkworm stocks. Most of the hibernating high yielding races of Japanese and European races are homozygous for Amy dⁿ Detailed characterizations of silkworm germplasm stocks are vital for the effective use in potential breeding resources. Hierarchical agglomerative clustering by UPGMA method using Euclidean distance of 54 stocks on the basis of yield attributes alone resulted in 7 clusters indicating the significance of such data in the characterization and classification of silkworm germplasm stocks(Chatterjee and Datta, 1992). The categorization of silkworm strains into five yielding groups on the basis of discrimination function scores of economic characters and esterase isozyme activity at different developmental stages was done on twenty silkworm genotypes (Ram and Lal, 2002).

Biochemical marker for genetic variations

Studies carried out on biochemical characterization of silkworm races of different origins from germplasm stocks with four metabolic enzymes viz., a esterase, b esterase , acid phosphatase, and alkaline phosphatase were able to compare and relate the genetic relationship among 14 MV races viz., Pure Mysore, Sarupat, Moria, Tamil Nadu white, C.Nichi, Hosa Mysore, Mysore Princes, Kolar Gold, Kollegal Jawan, MY-1, P2D1, Rong Daizo, Guangnang and OS-616 and 14 BV races viz., Alps jaunne, Alps yellow, Cevenesse yellow, Ascoli yellow, Meigtsu, B-36, B-37, B-39, B-40, J-112, J-122, Yakwei, Changnaung and C-122. The results on electrophoretic variation on isozyme profiles are seen in the band mobility (Fig. 1a,b).

Fig.1a. Genetic polymorphism on esterase isozyme among 14 MV races. Various bands designated as A,B,C & D.

Fig.1b. Genetic polymorphism on esterase isozyme among 14 BV races. Various bands designated as A,B,C & D.

A total of 4 bands was observed in multivoltine races and 7 bands in bivoltine races. All the observed 4 bands in multivoltine and 7 bands in bivoltine were not present uniformly in all 28 races studied. These variable bands present in them were identified as race specific markers and analysed through pop-gene software package for genetic analysis (Yeh et al., 1999). Thus 9 clustering groups were identified among 14 multivoltine races and 8 clustering groups among 14 bivoltine races.
The clustering helps us to relate their origin, racial characters and the parentage of the evolved breeds. Among 14 MV silkworm races studied, higher genetic distance was seen between C.Nichi (Original race of Japan origin) and Rong Daizo (Evolved breed of China origin). Similarly in BV silkworm races, such higher genetic distance was observed between B-36 (Japan origin) and C-122 (China origin). A detailed study on biochemical characterization in these line and proper classification of germplasm stocks is vital for the effective use in potential breeding resources. The genetic diversity and population genetic structure of twelve silkworm races revealed in the present study would be utilized for an effective conservation plan and breeding strategies. Based on the results observed in the present study, it is inferred that populations of silkworm races J-112 and NB4D2 would be very useful in a breeding programme, because their higher genetic diversity and alleles.

Storage protein profiles for genetic variations.

Studies on storage protein expression in the final instar larvae of silkworm races help to identify and cluster them based on the genetic variability in storage protein profiles. Storage protein variation was studied in eleven popular multivoltine silkworm (Bombyx mori) breeds encompassing different parentage and origin, as furnished in table 4. The main feature of storage protein variation in the multivoltines is found to be inter-origin variability in unit area expression of storage protein. The storage protein levels (SP-2) among these popular breeds as seen in SDS-PAGE also differed as evident from the SDS PAGE profiles in Fig. 2.

Table 4:Variability in protein expression of storage protein (SP-2) level in

multivoltine Silkworm breeds of Bombyx mori

Fig.2. Genetic polymorphism on storage proteins in 11 MV silkworm races

Based on densitometry scanning of SDS-PAGE bands of storage protein levels, six clustering of eleven races was done using Ward’s Minimum Variance clustering analysis. Storage protein has an important role to play on metamorphic features of larval weight and pupation rate of B.mori as evident from correlation factors. Thus study on genetic variability existing among storage protein level in silkworm breeds may be useful to cluster the silkworm races into different clusters having similarity in the storage proteins and their effect on growth traits.

Heat stable esterase isozyme profiles for thermo tolerance

The climatic condition of tropics, particularly in summer is not conducive to rear high yielding bivoltine hybrids. Keeping this in view, characterization of silkworm breeds for thermo tolerance is imperative in order to utilize such those identified thermo tolerant breeds in the breeding plan to evolve productive bivoltine /multivoltine breeds/hybrids. Genetic dissection of silkworm races carried out by several Japanese scientists (Sarkar, 1998) has indicated that certain enzymes are responsible for hardiness and related quantitative characters. Wu et al (1993) reported that the thermo tolerance varies with strains and is positively relative to the activity of a heat stable esterase (HsEST) analysed in larval body or midgut. This enzyme activity can be used as an indicator for the silkworm thermo tolerance. Further, there is always a heritable linkage between characteristics of high temperature tolerance and disease resistance (Samson and Chandrashekaraiah, 1998). In view of this, breeds with such trait should be characterized in the germplasm as resource materials for developing thermo tolerant breeds/hybrids. Non specific b-esterase band (Est 3) in haemolymph of CB5 (GP) and its syngenic lines among the silkworm stocks withstood a temperature up to 80 ±° C for 10 min indicating naturally available thermo stable esterase protein in the haemolymph of thermo tolerant races (Chattopadhyay et al., 2001). With this main objective, the presence of heat stable esterase isozyme band activity was studied in selected silkworm races along with thermo tolerant races CSR-18 and CSR-19 to identify such those breeds which can withstand higher temperature prevailing in some of the areas where during summer the temperature may shoot up to 40 °C and above. A total 10 MV races viz. Pure Mysore, Nistari, A25, A4e, PMX, MU-1, MU-11,MW-13, LMP and LMO and 12 BV races viz., Meigitsu, J-112, Chukwei, Sanish-17, Sanish-18 (P), JD6, JAM-125, PAM-105, BL-1, NB4D2, CSR-18 and CSR-19 has been studied for heat stable esterase isozyme activity to relate thermal tolerance in the above silkworm races. Heat stable esterase isozyme study showed the presence of active b-esterase band in multivoltine silkworm races of Pure Mysore, Nistari, A25, A4e, MW-13,LMP and LMO and in Chaukwei, PAM-105,BL-1,CSR-18 and CSR-19 of bivoltine silkworm races. Such active b-esterase band was absent in multivoltine races of MU-1, MU-11 and PMX and in Meigtsu, J-112, Sanish-17, Sanish (18), JD-6, JAM-125, NB4D2 in bivoltine silkworm races. The presence of active b-esterase band in the haemolymph of silkworm races may be responsible for thermo tolerance. The differential Esterase isozyme band activity observed in 11 multivoltine and bvoltine breeds is furnished in table 5.

Table 5: Esterase isozyme band activity in the haemolymph of MV & BV races

Conclusion

Biochemical markers on higher amylase activity and the presence of Amy dⁿ allele in homozygous conditions are useful to identify multivoltine and bivoltine silkworm races with strong amylase activity. 54 silkworm germplasm stocks were grouped into 7 clusters on the basis of yield attributes and amylase activity. Allozyme techniques were used on twelve silkworm races with different geographic origin to identify the genetic similarity and genetic diversity among them. The results showed six clusters and among them NB4D2 and NB18 are found to be genetically similar while BL-24 and Nistari are found to be genetically distant races. Silkworm races J-112 and NB4D2 showed the highest genetic diversity, per cent polymorphism and more alleles respectively. Storage protein expression level in the haemolymph proteins analyzed in different silkworm races is found to be useful in identifying robustness of the race/breed having inherent genetic potential for growth and cocoon yield. Presence of mid-gut esterase band 5 in thermo tolerant silkworm breeds and the presence of active b-esterase band in the haemolymph of silkworm races could be used as a biochemical marker to relate thermo tolerance in silkworm genetic resources. From the findings of the series of studies we make a strong argument in favor of using protein markers as a reliable tool for screening silkworm germplasms resources in commercial hybridization programmes.

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HAIL DAMAGE OF MULBERRY IN JAMMU

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Mon, 17 Jun 2013 09:45:00 +0000

Dr. R.K.PANDEY

Scientist, Regional Sericultural Research Station, Miran Sahib, Jammu, India

Dr. Pandey graduated from the University of Allahabad and completed his Master’s degree in Botany in the year 1975. Before joining Central Silk Board in the year 1981, he completed his Ph. D. in Botany from the Banaras Hindu University in 1980. Currently he is a senior scientist at Regional Sericultural Research Station Miransahib,Jammu , INDIA.

E mail: pandeyjammu@gmail.com; Phone: 09419107831, Fax: 01923 263339

RK. Pandey

Mulberry trees are grown in the state of Jammu and Kashmir in both temperate and sub-tropical zones for the production of silk cocoons by rearing silkworms on mulberry leaves in spring season (Dhar, 2011). The productivity of silk cocoons at farmer level depends upon the availability of mulberry leaves. The natural calamities such as frost, snow fall, and hailstorm affect the availability of mulberry leaves at the time of rearing during March in Jammu region and during May in Kashmir Valley. Ahanger et al., (2013) have reported reaction of mulberry germplasm to frost damage in Kashmir. In sub tropical Jammu region, hail storms in January and February damage crop plants by shredding thin leaves on plants and causing bruises and pockmarks. Almost every year agriculture department assesses damage to crop plants after hailstorm and Government compensates those farmers, who loose crop substantially. Broad-leaved plants such as mulberry are also severely damaged but no quantitative assessment has been reported so far. Successful plant recovery depends on the type of plant damaged, plant maturity and time in the season hailstorm occurred. Carefully assessing the damage is the first step, noting which varieties are damaged and which ones will survive becomes, as such imperative. In the present workdamage to young saplings of eight newly evolved Morus alba varieties was evaluated after a heavy hailstorm that occurred at Jammu on 27^th February, 2013

Stem Cuttings of eight new Morus alba varieties as shown in Table I, evolved by different Research Institutes, were planted in the last week of December under Randomised Block Design with six replications/variety at Regional Sericultural Research Station, Miransahib, Jammu in freshly prepared nursery containing well dried pulverized garden soil and well decomposed farm yard manure and maintained with consistent care (Jolly and Dandin, 1986). The sprouting per cent was recorded 60 days after planting. A violent hailstorm hit Jammu on 27^th February at about 7: PM in which volleys of ice balls continued for about 18 minutes. The white stones of ice with their size ranging from two to three centimeters suddenly started hitting and considerably stripped off the young newly sprouted mulberry leaves. The effect of hailstorm on young sprouted leaves was assessed on 5^th March, 2013, nearly a week after the hailstorm. The loss due to hailstorm was again calculated after 120 days to give sufficient time for recovery to the hail damaged saplings and record recovery, if any. The loss of sprouted saplings due to hailstorm was calculated, by subtracting per cent sprouted saplings after hailstorm from per cent sprouted saplings before hailstorm. The data collected was subjected to statistical analysis by adopting methods of analysis of variance appropriate to the design of the experiment (Sundarraj et.al., 1972).

Fig.1. Morus alba var. S-1635, sprouted cuttings

The data presented in Table I shows that per cent sprouting of cuttings prior to hail damage was found to vary between 83.66 and 97.66. However, the initial sprouting differences among the varieties tested were non-significant before the hailstorm as per analysis of variance. One week after the hailstorm, it was observed that 29.84% sprouted leaves of variety S-1635 were damaged followed by 16.83% damage in S146, 11.66% in Vishala, 11.00% in C-2038, 8.17% in TR-10, 6.83% in Chak Mazra, 6.16% in FYT-99/G4 and 3.5% damage in Suvarna-2. It can be further seen from the Table-I that the recovery after hail damage was observed 7.67% only in S-1635 variety; whereas, none of other seven varieties could show any recovery after hail damage

Table I: Effect of hailstorm on sprouted saplings of different Morus alba varieties

Young newly sprouted mulberry leaves become shredded, pock marked or ripped by hail. Hailstorm damage can severely decimate the leaf harvest for silkworm rearing in spring season.

Summary

An effort was made to assess the recovery after hail damage during February – March 2013 among eight Morus alba varieties at Regional Sericultural Research Station, Miransahib, Jammu. The damage was recorded as sprouting per cent after one week of the hailstorm and was compared with the sprouting % prior to hail damage. The recovery was assessed after 120 days of hail damage in terms of sprouting per cent. It was found that the hail damage was highest in S-1635 (29.84%), followed by S-146 (16.83), Vishala (11.66), C-2038 (11.00), TR-10 (8.17), Chak Mazra (6.83), FYT-99/G4 (6.16), and Suvarna-2 (3.5). However, it was only S-1635, which showed recovery of 7.67% after 120 days, while others showed further loss. Therefore, it is recommended to propagate Morus alba variety S-1635 at farmer’s level in sub tropical Jammu area.

LITERATURE CITED

Ahanger M.R., Ramegowda G.K., Illahi,I., Rizvi G., Dhar A. and Sahaf K.A.2013. Reaction of Mulberry germplasm to frost damage in Kashmir. Res. J. of Agri. Sci. 4(2), 180-183.

Dhar A. 2011. Mulberry sericulture in Jammu and Kashmir-An insight. Proc. workshop on Recent trends in development of bivoltine sericulture in Jammu and Kashmir. 29^th October 2011, SKICC, Srinagar, Kashmir, pp7-13.

Jolly M.S. and Dandin S.B. 1986. Collection, Conservation and evaluation of mulberry (Morus spp) germplasm. CSR&TI Mysore, India .43.

Rajat Mohan, Tewary R., Dhar A., Singh S., Bhat M.M. and Khan M.A. 2010. Sericulture & Environment are complimentary: Plantation of improved mulberry genotypes at different altitudes of Himanchal Pradesh. The Bioscan, 1, 217-224.

Sundarraj G.L., Nagaraju M.N., Venkataramu and Jaganath. 1972. Origin and analysis of field experiments. UAS, MISC .Series No.22, Bangalore, India, 424-440.

Insect growth regulators in sericulture- towards self sufficiency in farm level manufacture

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 08 May 2013 07:27:00 +0000

C.M. Sreejit^1,3, Sasi Kuthannur²,Chinchu Bose¹ and A. Banerji¹

¹School of Biotechnology, Amrita Viswa Vidyapeetam, Amritapuri, Kollam, Kerala, 690525.

² Kerala Sericulture Farmers Association, Nedungode kalam, Kuthannur, Palakkad, Kerala.

³Present address: Research Department of Botany, S. N. M. College Maliankara, Maliankara PO, Ernakulam, Kerala, 683516.

Technology innovations have helped Indian sericulture in taking giant strides ahead. Probably there are few agricultural enterprises in India, as technology intensive as sericulture. However there is a down-side to this. Some of these technologies are very costly and hence literally not accessible by farmers. The IGR technologies used in sericulture is an example. IGRs can help sericulturists a great deal by regulating larval duration for economic benefit. As most of these bio-molecules are either being imported or being replaced with costly synthetic mimetics / analogues; they are less accessible to farmers. The research group lead by Prof. A. Banerji at School of Biotechnology, Amrita Viswa Vidyapeetam, Amritapuri, Kollam, Kerala has been toiling over past few years screening candidate phyto chemical molecules with potential IGR properties and in fine tuning protocols for extraction and preparation of them at farmer level. Read on further about this work, which hold promise to sericulture farmers across developing economies.

Insect growth regulators (IGR) are routinely used in countries like, China, Japan, France for the management of sericulture and increasing silk-production. IGR’s have been comparatively recently introduced in the Indian scenario. Difficulties in procuring the reliable sources of IGR’s have been major impediment in popularizing IGR’s in India. As a part of our bio prospection of flora of Wayanad District, Kerala for bioactive molecules, several sustainable sources of insect growth regulators (IGR) were identified. Plants such as Diploclisia glaucescens (Blume) Diels, Coscinium fenestratum (Gaertn.) Colebr, Cyathula prostrata (L.) Blume, Sesuvium portulacastrum (L.) L. etc. were found to be good sources of phytoecdysoids (PEC). Eco-friendly methods of extraction and isolation of PEC’s have been developed . We also isolated and characterized several juvenoids (JHA) from indigenous plant sources. These discoveries prompted us to undertake the field trials on application of IGR’s in sericulture. The aim of the trials was to develop and transfer technology for efficiently utilising the local plants for improving the management and increasing the yield of silk fibre for the benefit of farmers.

The field trials were initiated in the rearing facilities of one of the authors, Sasi Kuthanur Palakkad. Another farmer, Sivan from Kannadi Panchayath, Palakkad District Kerala also offered his farm for conducting trials. Both the farmers have long hands- on experience in sericulture. The study was conducted during 6 months from July 2012 to December 2012 in their farms.

Bivoltine double hybrids (FC₁x FC₂) were brought in the second instar stage from Chawki Rearing Centre, and grown under the field conditions. Temperature was maintained at 23 + 3^oC and the relative humidity was adjusted to 75 + 5 %. 12 hours day/ night period was used during the study period. Mulberry leaves of ‘Victory 1’ genotype was obtained from a periodically watered garden and was fed to the larvae liberally three times a day. Isolation of PEC was carried out in the Phytochemistry Laboratory of Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam District, Kerala.

Amongst several sources, Diploclisia glaucescens (Blume) Diels, and Coscinium fenestratum (Gaertn.), both collected from Wayanad District , Kerala were used for the present trials. PEC’s isolated from these species have not been used in sericulture experiments earlier. PEC’s were fully characterized by their physico-chemical properties (UV, IR, NMR, TLC-UV,HPLC-DADS and LC-MS/MS).

The time and dose of application of PEC’s are very crucial. Aqueous solutions of PEC of appropriate concentrations were sprayed on to fresh V1 genotype mulberry leaves and was allowed to dry in shade for 30 minutes. The treated leaves were fed to larvae as the last feed. Mounting of larvae is a cumbersome process and require continuous care and labour. If the cocooning is not synchronised, the larvae which are late in cocooning may damage the already cocooned shells by their excretion by changing their colour to brown and reducing their marketability. PEC induces speedy and synchronised maturation of larvae when applied at the proper time. In our experiments also, PEC at 10 ppm level hastened cocooning. After 18 hours from the time of spray most of the larvae (90%) completed maturation and started spinning.

Like phytoecdysteroids,there were many plant extracts which showed juvenile hormone-like activity . One of the compounds was characterized as bakuchiol (BK) by chemical and physical (UV,IR,TLC, HPLC-DAD, NMR, MS) properties. A sample of BK was prepared as an emulsion in water. BK emulsions with different concentrations were applied Bombyx mori L. larvae 48 hours after the first feed in fifth instar stage. The concentration range was selected in the broad range of 1-10 ppm. The emulsions of appropriate concentrations were directly sprayed on to the larvae using a garden sprayer. After 30 minutes they were provided with fresh feed.

The effective concentration range for BK was 1-3 ppm. Above this range, linear increase in economic parameters was not obtained. Hence it was concluded that concentration of 2-3 ppm was optimum for this variety of silkworm in this geographical region.

A 12 to 20 % increase in larval weight on the sixth day of fifth instar stage was recorded within the effective concentration range of BK for the silkworm larvae from our studies in the two farms. A 15 to 25% increase was obtained within this range of BK concentration for individual cocoon weight. Shell weight also showed a similar pattern of increase with that of cocoon weight. Within the effective concentration range, 15 -30% increases were obtained with BK from the two field -levels trials. Medium control did not show significant increase over the general control with respect to cocoon weight. In our experiments linear increase of economic parameters continued till 3 ppm. Improvement in cocoon weight and shell weight on administration of synthetic JH analogues have been reported earlier. In the present trial no extension in larval period was observed when compared to medium and general controls.

Using combination of both JHA and MH on the same batch at appropriate times and dose, both increase in economic parameters and hastening of maturation occurred simultaneously with synchronisation of spinning.

As a concluding note it can be said that juvenoid, BK can be used in sericulture for yield improvement as it induces a favourable hormetic action in silkworm. In the concentration range (1-3 ppm) it brings about considerable increase in economic traits with respect to this geographical region and the bivoltine variety studied. Phytoecdysoids (PEC) is highly active in hastening the larval maturation and reducing the mounting time without any significant reduction in economic parameters. Both these compounds can be recommended for sericulture in this region. The plants are readily available and simple economic isolation procedures have been developed. The protocol for preparation of the IGR’s for spray is very simple and economical. The farmers can be trained to prepare their own IGR extracts without any significant expenditure. To our knowledge, only one or two companies supply JHA preparations which are based on imported JHA. So indigenous development of IGR’S from local flora will go long way in supplementing the income of farmers.

References

A.Banerji, A monograph :Alternate Strategies of Insect control - natural products as potential biocides. Bhabha Atomic Reserch Centre, Bombay, BARC-1416 (1988).

N KJoshi, H. B. Mansukhani, D. R. Suryavanshi and A. Banerji, JH effects of a weed plant, Psoralea corylifolia on the metamorphosis of red cotton bug, Dysdercus koenigii. Symposium on Biological approach to problems in medicine, Industry and Agriculture, BARC, Bombay, 36 (1974).

G.R. Shivakumar, K.V.A . Raman, S.B. Magadum, R. K. Datta , S.S. Hussain , A. Banerji, S.K.Chowdhary, 1996. Effect of phytoecdysteroids on the spinning, cocoon and reeling parameters of the silkworm Bombyx mori L., Allelopathy Journal, 3, 71-76.

K. S.Nair , J.S. Nair , K. Trivedy, V.A. Vijayan, 2003. Influence of backuchiol, a JH analogue from Bemchi (Psoralia corylifolia) on silk production in silkworm Bombyx mori L.(Bombycidae: Lepidoptera). J Appl. Sci. Environ. Mgt., 7(2), 31-38.

Read previous articles on IGRs by i) A. Banerji ii)N. Chandramohan

Shedding light on silk’s secrets using Raman’s discovery

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Tue, 16 Apr 2013 08:46:00 +0000

Maxime Boulet-Audet

Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK. Email: maxime.boulet-audet@zoo.ox.ac.uk

Maxime Boulet-Audet

In spite of the glitter and glamour associated with silk and its excellent properties as a textile fibre, the world raw silk production has been declining over the years. During 2006 - 11 the world silk production fell by 14.6% and its trend shows an inverse relationship with the (growth of) economic well being of silk producing countries. However, developed and technologically advanced countries recently show renewed interest on silk, as a ‘material for future’. That Oxford University hosts an exclusive centre ‘OxfordSilk Group’ under the leadership of such a famous zoologist as Prof. FritzVollrath, is a glowing example.

Maxime Boulet-Audet is a doctoral researcher at the University of Oxford- Merton College; within the Oxford Silk group. His project is supported by a NSERC Doctorate Scholarship from the Canadian government and by an EPSRC Next Generation Users Studentship from the UK government. Maxime’s work is to investigate why and how silk proteins have been optimised for flow processing. His multidisciplinary project introduced novel integrated rheo-spectroscopic tools to study silk protein structures in solution dynamically. Specifically, he coupled infrared spectroscopy and small angle x-ray scattering to rheology to monitor the development of silk’s multiscale hierarchical structures. In this article Maxime explains the application of Raman Spectroscopy in elucidating the molecular structure of silk fibre and in explaining its physical properties.

For millennia, Silk has been praised by the textile industry for its soft feel on skin. Its softness comes from its microscopic diameter as well as its incredibly smooth surface. Recently, it has been found that its size is also responsible for its remarkable strength[1]. Silk’s fineness however makes it challenging to study its structure. This is where Sir C.V. Raman’s discovery becomes handy. The coupling of Raman spectroscopy with confocal microscopy, Raman spectromicroscopy, is perfectly suited to investigate these fine fibres. This article describes the vast potential of the technique as well as its important contribution toward our understanding of silk’s spinning.

Silk’s lustre, toughness and biocompatibility drove researchers for decades to produce a comparable analogue. Among those attempts, nitro-cellulose manage to mimic silk’s lustre, but had the distempering tendency to ignite violently when brought close to a flame[2]. In fact, silk’s fire retardation property is often used to tell apart natural and the artificial fibres. Besides, those failed attempts; efforts directed at mimicking this biological material have given us valuable textile fibres like nylon and Kevlar which share some chemical similarities with natural silk. However, silk still have many secrets to reveal before it can be successfully mimicked.

Even though it represents the bulk of commercial silk production, ‘mulberry silk’ is only one among thousands of types of silks produced by arthropods. It is also produced by bees[3], marine barnacles[4] and all spider species[5]. As thinnest silk fibres are only few hundreds of nanometres, their size can make it challenging to study as few techniques can probe the structure of a single silk fibre. A technique particularly well suited for Raman spectromicroscopy as it is only circumscribed by the diffraction limit of light. Raman spectromicroscopy can extract information on the molecular structure from an area as small as one square micrometre (1 µm²). The technique is illustrated in the figure.

Raman spectromicroscopy of silk: drawing by Maxime

To start this technique requires a monochromatic laser beam. Its shape is defined using a pinhole before been reflected by the narrow band notch filter. Relying on destructive interference, the notch filter is designed to reflect only the wavelength of the laser to the microscope lens. The microscope objective then focuses the beam onto the probed filament. In addition, the probe area can directly visualise with a polychromatic light using the same optics.

Most of the photons directed to the sample will excite its molecules to a virtual energy state before relaxing back to the fundamental state, emitting back photons of the same wavelength. This elastic event is described as the Rayleigh Raman scattering and represents most of the light collected back by the microscope’s objective. However, a small fraction of the molecules excited to their virtual energy state will relax to an excited vibrational state instead, emitting photons with longer wavelength than the laser resulting. The photons scattered which have lost energy represent the stoke Raman scattering. On the other hand, the reverse (Anti-stokes) is also possible, but less likely by two orders of magnitudes. The difference between the incident and emitted light frequency is thus linked to the vibration energy of the sample’s molecular bonds. As the frequency measured is related to the type of molecular bond present, we can extract information on the molecular structure from the frequency difference of the stoke scattering. Thus the optics of Raman spectrometers aim at separating the stoke Raman scattering containing the information on the molecular vibration from the rest of the back scattered light. This is archived using the notch filter which rejects the Rayleigh scattering, but allows the Raman scattering through. The confocal plane is then set by another pinhole before the light is dispersed by a grating acting like a prism. The light is then detected using a high performance monochrome CCD detector similar to those of professional digital cameras. The position on the detector can then be directly related to the light’s wavelength or frequency. The resulting spectra commonly display the light intensity count as a function of the frequency difference or Raman shift.

Silk Raman spectra contain a wealth of information with many bands characteristic of samples’ molecular vibrations. From these spectra we can deduce the protein 3D structure (conformation) as well as identifying the amino acid side chain. By adding filters along the beam path, we select the polarisation of light to obtain information on the molecular orientation in the fibres. For instance, the alignment of the molecules can thus be quantified and related to the material’s mechanical properties[6]. In addition, the sample can be mounted on a stage to be mapped. It then allows the juxtaposition of the chemical map on the sample’s image. Another advantage of confocal microscopy is its ability to set the focal plane depth, allowing vertical axis mapping as well. It can even probe inside transparent containers. This way we can follow the progression of the molecular structure inside the animal’s silk storage gland, in the spinning duct and outside once spun, telling us the silk’s spinning story from beginning to the end[7].

Each type of silk gives a unique spectrum, which can be used as a unique molecular fingerprint. This fingerprint can even discriminate between original and counterfeit drugs without even opening the pack. It can also be used to identify unknown type of silk or evaluate how closely they are related to one another. There are even differences in silks from the same animal, as each of the 7 types of silks produced by some spiders has a unique Raman signature [8]. This is not surprising knowing that spiders have evolved different types of silks over 400 million years with particular mechanical properties for specific functions: mobility, predation, protection and reproduction[9].

For some colourful samples, a competing phenomenon, fluorescence can potentially mask the Raman scattering. Fortunately, for the majority of silk samples this does not pose a major problem. Heat damage can also become an issue when using a powerful laser on a microscopic area. A longer wavelength can help avoiding both issues, but the intensity trade-off is important as scattering is proportional to the power 4 of the wavelength (doubling the wavelength decreases the signal by a factor of 16). The scattering intensity dependant on the wavelength also explains why the sky is blue as red light is less scattered by the atmosphere than blue.

Overall, Raman spectromicroscopy is perfectly suited to probe silk in all its forms: liquid, fibre, films or scaffolding. It also offers a tool to monitor its structure when stress is applied, mechanical or chemical. This technique proved very valuable for the investigation of the spinning process by revealing the protein conformation, molecular orientation and composition at any point in the production process, for any given species. These insights made a significant contribution to our understanding of the natural silk spinning. Hopefully once we know enough about Nature’s secrets, the development of artificial silk should result in comparable analogue.

References

1.Porter, D., J. Guan, and F. Vollrath, Spider Silk: Super Material or Thin Fibre? Adv Mater, 2012.

2.Le Couteur, P. and J. Burreson, Napoleon's buttons : how 17 molecules changed history2003, New York: Jeremy P. Tarcher/Putnam.

3.Sutherland, T.D., et al., Single honeybee silk protein mimics properties of multi-protein silk. Plos One, 2011. 6(2): p. e16489.

4.Kronenberger, K., C. Dicko, and F. Vollrath, A novel marine silk. Naturwissenschaften, 2011.

5.Lutz, F.E., Preserving Spiders' Webs. Science, 1906. 23(584): p. 391.

6.Lefèvre, T., et al., Study by Raman spectromicroscopy of the effect of tensile deformation on the molecular structure of Bombyx mori silk. Vibrational Spectroscopy, 2009. 51(1): p. 136-141.

7.Lefèvre, T., et al., Conformational and orientational transformation of silk proteins in the major ampullate gland of Nephila clavipes spiders. Biomacromolecules, 2008. 9(9): p. 2399-2407.

8.Lefevre, T., et al., Diversity of Molecular Transformations Involved in the Formation of Spider Silks. Journal of Molecular Biology, 2011. 405(1): p. 238-253.

9.Brunetta, L. and C.L. Craig, Spider silk : evolution and 400 million years of spinning, waiting, snagging, and mating2010, New Haven: Yale University Press.

Giant African snail (Achatina fulica Bowdich, 1822) - As a Molluscan Pest: First Report on Mulberry from Aurangabad, (M.S), India

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Mon, 01 Apr 2013 18:16:00 +0000

Sunil B. Avhad and Chandrashekar J. Hiware

Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S), India.

E-mail- sunil_zoology@rediffmail.com, drhiware@rediffmail.com

Sunil B. Avhad

Abstract: The Molluscan as a pest of agriculture and horticulture have already been known in many regions. The present communication deals with molluscan pest the Giant African snail; Achatina fulica (Bowdich, 1822) observed a first report on mulberry fields from Aurangabad district, Maharashtra during June.2009- May. 2011. The incidence of snails was recorded in all the tehsils, in the every months starting from August to December. According to sericulturists of the area, severe cocoon loss was not only due to infestation but also due to the stinking smell of mucus layer (both wet and dry conditions) released by the Giant African snail, Achatina fulica on mulberry plant. The silkworm showed an aversion towards feeding on such leaves and as result, considerable quantities of harvested leaves were wasted without converting in to silk cocoons.

Key-words: Giant African snail, Molluscan pest, Mulberry, Aurangabad. Maharashtra state.

Introduction:

In India, sericulture is one of the most important agro and forest based cottage industry, earning a foreign exchange of Rs. 400 corers / annum and providing gainful employment to over six million peoples. Technically sericulture is rearing of silkworms either on mulberry or non-mulberry plants for production of silk. Today India is the second largest silk producer of raw silk and also has the distinction of being the world’s largest consumer of silk. In developing countries such as India, agriculture and agro-based industries play a vital role in the improvement of rural economy. The limited availability of land, the limited cash returns and agriculture being confirmed to one or two seasons in the year, have made villages to look for supporting rural industries and one of them is sericulture. Maharashtra, a state without a tradition of silk production has a large gap between demand and supply of raw silk and more than 4,000 (Anon., 2008). This demand for raw silk could become a source of rural employment within Maharashtra. The main constraints to sericulture in Maharashtra state were: lack of mulberry tree varieties adapted to local agro-climatic conditions, lack of suitable silkworm races, and lack of knowledge and skills among the farmers.

Mulberry (Morus spp.) leaf is the only natural food for the silkworm, Bombyx mori L. It is a perennial, evergreen, luxuriant crop cultivated in all types of soils, both under rainfed and irrigated conditions. The crop is prone to depredation of diverse organisms, because of its fast growth and green foliage throughout the year, in varying proportions either for space, food or both. So far, over 300 insect and non-insect species of pests are known to infest mulberry in varying intensities during different stages of the crop and seasons (Naik, 1997). Though the frequent leaf picking and pruning of the attack of pests, many of them still final enough time and place on mulberry for feeding and breeding on it. From India, about 100 insect pests have been reported on various varieties of mulberry.

Among the non- insect pests of agricultural as well as horticultural crops, the Giant African snail, Achatina fulica Bowdich is reported as most important one in many parts of the world. The characteristic symptom of the infestation was that the snails were feeding on the bark of the stem. This brings down the nutritive value as the vascular is injured and senescence of mulberry leaves leading to defoliation. The incidence is one of the major factors that decide the productivity and profitability in sericulture is the maximization of quality mulberry leaf yield per unit area. However, the mulberry leaves from snail attacked plants are not suitable for silkworm feeding as they are found to be nutritionally inferior (Shree et al., 2006).

Materials and methods:

The molluscan pests’ collection was carried out in six sites namely Aurangabad, Sillod, Fulmbari, Khultabad, Paithan and Gangapur from June 2009 to May 2011. All the sites were visited and sampled monthly with different collection methods. All the specimens were identified with the help of available literature and Zoological Survey of India, Western office, Pune division, India.

Results and discussion:

Achatina fulica (Common name: Giant African snail, Phylum: Mollusca, Class: Gastropoda, Superfamily: Achatinoidea, Family: Achatinidae, Subfamily: Achatininae, Genus: Achatina, Species: fulica). Occurrence from the mulberry plant, Morus alba L., from Gangapur mulberry fields, Aurangabad district, Maharashtra, India throughout year but active during rainy season. Type of Damage and Symptoms is as extensive chewing of blossoms, leaves, and shoots stunts the growth of young trees and trees that have been top worked. The land snail can especially be a problem following wet winters and springs. Land snail feeding is not a problem in mature groves. Thick, dry leaf mulch suppresses snail numbers and large trees tolerate any modest chewing.

Giant African snail (Achatina fulica Bowdich)

The adult snails have a height of around 7 centimeters (2.8 in), and their length can reach 20 centimeters (7.9 in) or more. The shell has a conical shape, being about twice as high as it is broad. Either clockwise (sinistral) or counter-clockwise (dextral) directions can be observed in the coiling of the shell, although the right-handed (dextral) cone is the more common. Shell colouration is highly variable, and dependent on diet. Typically, brown is the predominant colour and the shell is banded (Skelley et al., 2011).

In the present study the occurrence of the Giant African snail, Achatina fulica is reported from Gangapur, Aurangabad (M.S), India mulberry field during rainy season but there occurrence is throughout the year, due to hibernation time these are not much active as compare to rainy season. Shree et al., (2006) also report on the occurrence of the Giant African snail, Achatina fulica in some parts of Karnataka is infest mulberry. The incidence of snails was recorded in all the villages, in the every months starting from August to December. According to sericulturists of the area, severe cocoon loss was not only due to infestation but also due to the stinking smell of mucus layer (both wet and dry conditions) released by the Giant African snail, Achatina fulica on mulberry plant. The silkworm showed an aversion towards feeding on such leaves and as result, considerable quantities of harvested leaves were wasted without converting in to silk cocoons.

Acknowledgement

The authors are thankful to the all the farmers from Aurangabad district and to the University authorities, Head, Department of Zoology, Dr. Babasaheb Ambedkar Marathwada University Aurangabad, (M.S.) India, for providing necessary laboratory and library facilities during this work.

References

Anonymous, (2008). Annual Progress Report, 2008, CRS, BAIF, Uruli Kanchan.

Naik, S. L. (1997). Bioecology of thrips infesting mulberry. M.Sc. Thesis, University of Agricultural Sciences, Bangalore 77p.

Shree, M. P; Ravi Kumar K and Nagaveni, V (2006). Infestation of Giant African Snail on Mulberry. Indian Silk, Vol.45, No.6, Pp. 14-16.

Skelley, P. E; Dixon, W. N; and Hodges, G. (2011). Giant African land snail and giant South American snails: field recognition. Florida Department of Agriculture and Consumer Services. Gainesville, Florida.

South Indian sericulture- portrait of a bygone era

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sun, 24 Mar 2013 12:57:00 +0000

Dr. Simon Charsley

An interview with K.V. Achuthan Nair, by Dr Simon Charsley, University of Glasgow

That Bangalore hosts International Sericultural Commission, is in recognition of the importance of South Indian Sericulture to global silk industry. The story, how sericulture took roots in these parts lay buried deep in history, relics sparse. What toils, earnest and selfless efforts have gone into its making! The story unfolds through this interview; conducted by Simon Charsley with K.V. Achuthan Nair (DD Seric Rtd, Department of Sericulture, Karnataka) on Friday 11 September 1992. Achuthan Nair passed away on 8^th August 2010, at 96.

To Achuthan Nair in the morning.

From Kerala originally but no family home left there: we discussed the tharavad[1] and its advantages a little.

Now 76, having retired at 55 in 1972, so must have been born 1916/ 17[2]. When he retired he thought it would be good to relax, take up some social work or some such, but people had kept coming to consult him about sericulture. They then asked him to keep the chemicals etc he was recommending so that they could get them conveniently. So he set up R.V. Enterprises[3]: they have their own product, Polmr dust[4] for grasserie and flacherie.

In 1943 he joined the Madras Department in Kollegal together with Punja[5], Ranganatha Rao[6], Venugopalan Nair[7] – 5 or 6 of them. It was hard because they had no stipend during the training period. At the time unemployment was very bad in Kerala. He knew someone in the government secretariat who let him know about the opportunity. So it was chance that he came to sericulture.

It was the war that gave impetus to it. The British Empire had no-one else to supply silk for parachutes and they asked all states to implement projects for it. Madras put up a project for making filature silk and was given 300 basins and the filature was started. Nobody worried about the supply of cocoons, but there were only 25,000 acres - or should this have been 2,500? - under mulberry and this would be sufficient for 50 basins only. So then they got further a project for expansion of the mulberry acreage, production of eggs, research, etc.

1958 training batch of All India Sericulture Institute, Mysore
Achuthan Nair is seen sitting fourth from left

During training they were taken to Berikai just south of the Mysore border, northeast of Hosur Town in Madras, because there were a few Muslims there rearing worms on just three acres of mulberry and the Department had a small unit for purchasing cuttings from them for use in new areas. It was indigenous varieties and they were very mixed. They would just select the better bushes in the field to take cuttings from.

At Denkanikottai there was also a little rearing going on. When they went there as students during training, it was very remote, no good communications. Just one bus and because of the petrol shortage this ran on charcoal: it burnt charcoal to make gas and ran on that. No sanitary conveniences or anywhere to get food. They joked about who would be the unlucky man to get posted there. When he actually was he was asked how he felt about it. He said 'I like it, sir'. Surprised, his officer asked why: 'Because you are posting me there', he said. There was no source of food there, and he also had a problem that after he graduated he had been given charge of the family land in his own place in Kerala.

It was a sort of sacrifice they made to go to such places, but he formed a club there, the Friends Union, out of the few educated people around, in the Department and others. They used to play cards but not for gambling. They got a badminton court in the farm and in the end people started coming there on leave.

But before that A.T.Janakiram[8] was his senior officer. He had joined as a Probationer as early as 1930 and had a reputation for being very strict and difficult about allowing anyone casual leave. But he came to visit, saw him there and asked V.R. Uttaman[9] who was his immediate superior (and still living at the time), why he had not given him leave: he looked reduced and needed to go home. He replied that he could not go because he had too much to do. 'I will look after your work', said Uttaman. Of course he did not; someone else was deputed to do it, but he was very appreciative of his efforts - but he did not reward him by giving him a transfer from that place.

One particular drawback of the place was that, if there were a reduction in the cocoon rate, everyone blamed him and came and pressured him, since he was alone there. He had also to be a bit deceitful since Kollegal had to have seed cocoons every day. If left to themselves, when one man cut his mulberry others would follow, so they tended to get everyone wanting to rear at once. He would have to prevent this happening by telling them that the layings were pebrinised: if they wanted to risk it that was up to them. 'No, sir, we will wait'. The seed cocoons went by van to Kollegal at night, via Bangalore, in special cylindrical baskets. These were bamboo with gaps for ventilation and lids and they travelled on their sides, piled to allow plenty of ventilation and avoid crushing. They would get to Kollegal in the early morning.

They also started a farm in Hosur with 80 acres under mulberry, under the big Andivadi tank. Government acquired the whole irrigated area, 100 acres and it was divided into 7 units, each run independently but co-ordinated by a senior officer. It was for rearing Foreign Race (FR) seed cocoons which also went to Kollegal, and there were good selected rearers around the farm too. Hosur Cattle Farm was where the basic FR seed was prepared, i.e. it was already an embryo P system. Stock races were maintained at Coonoor, with J(apan) and C(hina) nos. There were also farms at Berikai and Denkanikote for the improvement of the indigenous race. They were therefore quite independent of Mysore, except that they would get in Mysore race from time to time as new blood, to be crossed with their own. Apart from this there was a little rearing in Hindupur which was also in Madras at the time, and there were small demonstration farms there.

Locally, 'Pure Mysore' - so termed - was being reared, very crudely. They would allow the moths to emerge from the seed cocoons, mate, and the pairs would be removed to other trays. The males would be removed; the females would lay just on the tray itself, with no disinfection. Eggs would hatch and the worms would be fed on the same tray. They would then be given to whoever required them. It was not rearing as chawki but immediate selling. Later they began using paper for laying. Another practice was to keep eggs on brass eating plates. When the worms emerged they would feed them on the plates and cover the plate with tray. This was to keep them cool, and in the coolest part of the house. After second moult they would transfer them to ordinary trays.

The price of cocoons was very low, Annas 3-4 per lb., and why sericulture continued was questioned. The answer given was that Karnataka was airconditioned, i.e. very good for worms naturally, whatever rearers did to them. There were landlords with plenty of land, 30-40 acres under mulberry. They would go out and bring the leaf home, giving it to family members, the women, to rear. They might be taking 1000 layings for 30-40 acres, getting only 15-20 lbs per 100. The money was pocket money for the ladies, and the waste went for cattle food. The cuttings of mulberry would be stacked up like a haystack and would provide the fuel for months.

[Were tenants the rearers?] The basic idea was that it was the landlords themselves, but a portion of mulberry might be given to the poorest families on share basis. This was certainly happening then too. There was not much irrigation; most land was just rain-fed and by September the dry crops had been harvested and there was no work for the labourers. Sericulture could provide work for the idle labourers since the mulberry would still sprout up to Jan/Feb. Rearing, it seemed, was essentially by the family. SCs[10] could not enter houses of caste Hindus so could not work in rearing there. During menstruation ladies could not touch the worms. They said they were Lakshmi and there was puja to them, especially at moulting. This was felt to be a bad time for the worms when they had to be looked after well, hence the puja. An attachment to the worms was certainly felt. [This may actually refer more to Kollegal, since he went on to say that the Hosur rearers were almost all Muslims.]

So he joined the Department after training in 1944, and was posted as Seed Campaign Officer at Hosur for the indigenous seed. His job was to expand the mulberry planted and get people rearing. In the initial stages people were very resistant, fearing some calamity in the house if they took it up. When he approached they would also ask him, what was the charitable thing in rearing? If you grow sugarcane, the thief may come and take it and we may also offer it to visitors. So there was dharma in growing it. Where was the dharma in mulberry? Of course we may get money, but we do not want to do it. So he would contact an important man and go and visit him. They would enquire about the welfare of the country, and what his sons were doing, and would go away. He would repeat such visits. Eventually he would ask him to do one thing for his sake: plant 2 acres of mulberry. He would say 'Sir, for your sake I will plant it'. So he would guide him and rear the worms as if they were his own in that man's house.

For Muslim rearers, sericulture was convenient because their ladies were not allowed to go out, but inspection was a problem. They would have to inform them in advance that they were coming, so that they could bring the worms out. But then he used to tell them that if they insisted on this he could not make them seed rearers, so they then allowed the Department people in. In fact it was identified with Muslims and they had a joking term, 'Pashadega' or some such - about which he was worried in case it implied derogatory attitudes to another community – because it seemed to be all Pashas who did it.

He was also preparing the layings and issuing them, limiting it to 100-150 per shed. He had to prepare the layings himself; he could not entrust it to anyone else because if someone missed disease, it would be he himself who would be blamed by the Department and by the sericulturists.

Kollegal was a small area and the Department there could do everything very well. In Mysore they always had big areas and a large number of rearers to contend with, and this was more difficult. He was very preoccupied about not criticising the Mysoreans: they had been good to him, so he should not do so.

He also at times had some difficulty about being a Keralan[11] and running things in Karnataka, but clearly he does have the feeling that things do not quite work properly there. The Madras officers were well trained and they had experience of everything. Everywhere the rearing was in patches of several or single villages. Even distant villages might take it up because of some marriage connection, but even neighbouring villages might not. It was a matter of personal inconvenience and convictions. He stressed that village heads were very strong in those days. If a leader did not want it done, it would not be done. He accepted also the other way round: if a head wanted to introduce it, others would follow.

A good idea to regard the rearing area as made up of villages rather than individual rearers, with clusters and isolates, e.g. the three acres at Berikai where rearing somehow managed to persist. There the rearers, who were Muslims, would reel their own cocoons on charkas. After the seed area was established, such reeling was not allowed but in practice the reject cocoons which did not go for seed continued to be reeled locally. The main centres for sericulture in Kollegal were Kuntur, Kamagere and Hanur, a little at Palya, [i.e. not a very different pattern to subsequent.]

Kuntur: there is a story that Tipu passed that side and saw it. He had heard about Kollegal silk and announced 'This is Kollegal'. [The significance of the story is not quite clear, but it seems to be that Kollegal was claimed to have been identified with silk in Tipu’s time.] There is a pond in Kuntur which was said to have absolutely neutral water which was the source of the very good colour of the silk there. It was one of the early reeling places, also Doddinduvadi and Surapura.

Cocoons were purchased by reelers who would go to the rearers’ houses, see the worms and advance money for the cocoons. The rearers were then bound to sell to them. The reeler would take a handful and put it aside 'for God', before weighing the rest and paying for them. They also charged interest on the advance. It was to avoid this kind of thing that cocoon markets were set up. The reelers were Muslims mainly. ... [Discussion of prominent individual reelers].... Achuthan Nair did not know much about the silk trade. The Filature got cocoons from Mysore in the end. He thought there were small purchasers of silk in Kollegal but the big people like Rachegowda would go to B'lore. There were lots of cocoon brokers who took the cocoons to Mysore. The markets the Department set up were at Kollegal, by the filature, Kamagere and Hanur, but the cocoons from them were being bought for the filatures since there were no reelers coming to them.

Later in his career he was in charge of the silkworm gut manufacturing section at Coonoor. Ripe worms were soaked in acid and the gut was removed and stretched. Then the sericin was removed by boiling with soap. It was for external use only and was replaced with nylon, but that has disadvantages: people may be allergic to it and it snaps, neither of which happens with silkworm gut. Previously it had been produced in Spain by ladies incubating the cocoons under their breasts and exported to Johnson & Johnson in London: a complex and extraordinary tale in fact here. He also tried to develop gut for fishing as it is undetectable in water, and even to make brushes out of the waste, but the operation had to be closed.

Farewell to KV. Achuthan Nair, from All India Sericulture Institute,
on 31.03.1960 Mr. Nair is flanked by MN. Narasimhanna
on his right and NK. Guruprasad (Principal) on his left

1948-53 he was at the Hope Silk Farm in Hosur for FR production, and in 1956 when Kollegal joined Mysore he was Sericultural Superintendent in charge of the Central Grainage there.

Their separate organisation continued for some time. He then went to CSB as Sericultural Expert in the All-India Sericultural Training Institute here in Mysore. At the time research was still at Channapatna under the State government, but he was starting it at the Institute. All the sericultural processes had to be organised there and he trained two batches. They came from all over India and are now in good position everywhere.

He would have been happy to continue there but he had not had experience of serving in Karnataka. Had been in Madras [Hosur and Kollegal] with its different atmosphere: competitive and with the opportunity to have experience of all stages of sericulture. Uttaman became Director at this time. He called him and told him that there were vacancies at Chamarajanagar, Kolar and? Channapatna: which did he want? He said he wanted to go where he could best show good work. So Uttaman told him to take Chamarajanagar. There had previously been no organisation there and he had to establish everything. It also had the hill station at BR Hills and Uttaman thought his experience at Coonoor would be useful. So he organized the division. This was in 1960. He had to give technical advice to the villagers and there were farms to be opened. He wanted to purchase the land there where the Farm/and grainage are now, but the 21 or 25 Uppaligashetty landowners were not willing to part with it at the rate of compensation offered. ... [Account of obtaining land there, told off the record, apparently because it implied criticism of what went on in Karnataka.] ... . He was in charge of 3 taluks and had also to start chawki rearing there. The rearing at the time was by very crude methods and the object of the centres was to demonstrate better. For each there was a demonstrator and a labourer, supposed to be supervised by a committee of sericulturists. The committee was expected to lease mulberry land for the use of the centre but sometimes this was not possible. Then the farmers would have to bring in the leaves to feed their own worms. Maybe ten people would bring leaves from ten different gardens: that was not good as they tended to get mixed up in the feeding. If the committees had worked well, Chawki Rearing Centres (CRCs) – would not have turned out badly.

Sericulture was always a side industry. The poor man can't afford to produce a successful crop because of all the drawbacks he labours under in the form of shortage of resources. And for the rich man, he has other diversions, so is less interested. They used to consider sericulture as a poor man's industry, but just recently it has turned into a richman's.

Markets: along with the CRCs they were opening cocoon markets in Chamarajnagar. The first idea was that should be one within 5 miles of every rearer, so that he would be able to get there easily. They would have 4/5 reelers present for auctions and they would be forced to attend. But then the reelers would not come: suppose the rate was lower in some other market, they would want to go there. And rearers similarly. It was not possible to control it by legislation. A rearer went to court arguing that he had produced the cocoons and should be able to sell where he pleased. So they retained the markets where transactions were good, but in the end could not force people to use any particular one. Finally few survived but the big ones, and more people go to Ramanagaram. [So what about small markets like Harave and Hanur that still existed?] They were big markets earlier and still have some people wanting to sell only there. Harave was at a centee of rearing. Nearby is Maliyur with MLA[12] M.C. Basappa whose brother M.C. Swamy was a very good rearer from the beginning. He was an Agriculture graduate and used to take 400-500 layings and rear continuously. He is one of his customers for chemicals.

After the War there was a setback. Imports began and a tariff of 150% was imposed to maintain the home industry. It was sericulturists’ capacity to make use of idle labour which interested government, safeguarding the interests of labour. Indian silk was costly, hence the need for protection.

Killing silkworms: In Berikai there was a Tamil family, Gowdas, Mariswamy & Co. They were vegetable seed preparers and suppliers. They were good agriculturists and friends of his, and they used to attend his functions. He requested them to plant mulberry, but for all of 32 years’ friendship they resisted. They asked him not to press them. And it was the connection with killing worms which worried them. So there were some people who did think like that. A story of an orthodox Brahmin lady in Madras: when she saw a boy in charge of reeling she asked him what community he belonged to. He said he was an Iyengar Brahmin. She: ‘Why, being born as a Brahmin, should he do such a cruel action? Is it not sinful?’ Then seeing some silk fabric, she immediately wanted it. So the boy wanted to know, was that not sinful too? She: that it was different’.

The purity of silk: Pithambara = 'yellow silk' and it is mentioned in the Puranas as being used by the Gods. [Why?] Because silk is a non-conductor of heat and electricity. So even now Brahmins used to wear silk only. For worshipping, they didn't allow the pupa to be killed. Ripe worms are put on a plate and allowed to roam around producing silk. Maybe 5-6 and they move about the plate forming a sheet of silk, and this sheet is used to keep the idol on in old Brahmin homes. He himself clearly feels that it is a somewhat illegitimate betrayal of the silkworm to steal its cocoon and destroy it in the process, a creature dependent on man. But nowadays nobody has any such sentiments anymore.

Sericulture before Tipu. There were no sources for this. [This led him to stress how] in the 1940s there was no book to refer to for sericulture. Even when he was the sericulture man in the Institute he had to note down everything for himself. All aspects of science come together and interact in sericulture. He would discuss points that occurred to him with the specialists in Botany etc. [In fact there was already some good Indian literature, e.g. N.G.Mukerji’s Handbook of Sericulture of 1910/11, N. Rama Rao and M. Yonemura’s on silkworm rearing of 1925, Maxwell-Lefroy’s Report of 1916/17, On the Silk Industry of India, and others; but none have been easy to find.]

Any new people wanting to take up sericulture come to contact him. They come with grand notions of starting with 20-50 acres: he tells them to plant 2 acres for a start. Can then continue rearing from that and know all the pinpricks of sericulture. Then they can expand. If you fail after plunging in, you will fail really badly. His contribution he sees as increasing yield by 1 kg. He did have a scheme after retirement to set up a grainage and farm, get in other retired people to establish a consultancy service, but there were problems in getting a grainage licence etc, so he settled down with just himself and consultancy. The only thing is that he cannot go and visit the farms. If he went to one, he would have to go to all and that is impractical. But he does see private consultancy as the way the industry has to go.

He is also keen on people setting up local sericulture organisations, with their own grainages etc, on the Japanese model. [I commented that in the 1920s there had been so much talk of conferences and associations and that kind of thing, but it had gone away. Why were things different now?] He thought it was because there were so many more educated sericulturists now that it is increasingly possible to organise. Such a scheme with which he is associated - confidential - was now under application.

[Individual contacts: ... .]

He was also in the Seed Area for 5 years as Assistant Director in charge of the whole thing: in these days there are so many Deputy Directors and a Joint Director and still it does not run properly. He noted that it was cyclical, every 5 years. In 1965 there was talk of pebrine but with the co-operation of his staff they could easily control it. Responsibility is the thing. [I put it to him that in the early stages of the industry Brahmins had played a big part, subsequently Lingayats had been very important.] He agreed and also that this had something to do with the idea of service they had. Subsequently people just in it as jobs and not really interested. [The way things were running down was an inevitable theme, but there was also a very positive side to his account.]

[Mr Nair was, as seen above, a very interesting informant, a charming man as well. It was a pleasure to spend time with him, his delightful smile animating an otherwise aging face.]

Editors Notes

[1] Tharavad: name of the joint family of Hindus in Kerala. The Nair tharavad used to be a complex house hold with unique joint family lifestyle, now almost nonexistent.

[2] Achuthan Nairs’s son, Krishnan Unni confirms that Mr. Nair was born in February 1917 in a village called Cheramangalam in Palakkad district, Kerala State, South India. Having lost his parents at an early age, he grew up under protection of relatives and graduated from Annamalai University in Science (a rare achievement those days).

[3] RV Enterprises: Achuthan Nair set up his company together with Mallaraja Urs, Assistant Director Sericulture. R in the name came from Ratna Urs (Mrs Urs) and V from Valsala (Mrs Nair) - Reported by Sivakumar, Mr. Nair’s son.

[4] Krishnan Unni reports that the name ‘Polmr’(pronounced as ‘polmer’) was coined by Mr. Ravi Varma, a friend of Achuthan Nair, and then Area Manager of Kerala Soaps & Oils Limited (now Kerala Soaps), a state owned soap manufacturing company. Mr. Ravi Varma’s daughter Samyukta Varma is a well known Malayalam film actress. Both sons think that the rather strange name was created by combining the first letters of various chemical constituents of the powder. However they aren’t sure what these chemicals were.

[5] Former Deputy Director, Department of Sericulture, Karnataka

[6] Former Project Coordinator, National Silkworm seed Project, of CSB

[7] Former Director, Department of Sericulture, Karnataka

[8] Former member Secretary of CSB. He was instrumental in the foundation of Department of Sericulture, Uttar Pradesh.

[9] Former Director, Department of Sericulture, Karnataka

[10] Scheduled Caste: The Indian constitution recognizes list of scheduled castes and scheduled tribes eligible for various reservations on account of their socially deprived status.

[11] One hails from the southern state of Kerala, and speaks Malayalam; commonly called Malaylee.

[12] Member of (state) Legislative Assembly.

READ A PREVIOUS STORY BY Prof. CHARSLEY

Contact Prof Charsley: simoncharsley@yahoo.co.uk
Acknowledgements: We thank Mr. Krishnan Unni, CSR&TI, Mysore, to whose collections the two photographs belong and Mr. J. Justin Kumar, CSR&TI, Mysore who made available the scanned images. We are indebted to Mr. M.N.S.Iyengar, Joint Director, CSB (Retd) who (over telephone) shared some interesting information regarding individuals whose names appear in the text. This info is used in editor's note

Science in India- Raman's vision

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 27 Feb 2013 10:29:00 +0000

G.K. Rajesh

CEO and Member Secretary, Council for Nature Conservation and Environmental Protection, India

February 28, the day on which the discovery of Raman Effect was was officially announced by Sir. CV. Raman, is celebrated as 'National Science Day' in India. In the eve of National Science day, 2013, we remember Sir. CV. Raman, and his vision on scientific progress in India

Sir CV. Raman

The 2010 report of the Science Advisory Council to Prime Minister of India is titled “India as a Global Leader in Science”. It is interesting to see that the initial skepticism this title evokes in the minds of readers (about the validity of the claim) is shared by the authors. In the foreword to this vision-document, Dr Manmohan Singh, the Prime Minister asserts that it makes a realistic assessment of the opportunities that lie ahead and the challenges that the country face, in developing strong capabilities and acquiring global leadership in the area of science. The report in its very first page critically examines the validity of the growing perception around the world that India is one of the potential global leaders in science. Quoting a statement from the 2005 report of US National Academy of Science (NAS), that ‘the emergence of India and China as global leaders in science would pose challenges to the position held by US in the world of science’, it cautions the readers against getting carried away and categorically asserts that India is yet to become a major force in global science. The report goes on to illustrate that India has not produced any perceptible peak in the global distribution of number of scientific papers produced.

India’s strife towards building its own science began in the last decades of 19th century. This so called renaissance gave birth to a few world-class scientists in the country and one among them went on to bring home its first Nobel prize in science. Sir CV. Raman was a torch bearer of the Indian renaissance who strived till his last breath to cultivate true science in this country. This article takes a re-look at his vision and tries to assess the country’s progress in the lines envisioned by Raman.

The Nobel Prize won by C.V. Raman in 1930 for Physics was also India’s last one in science. It took 38 years for yet another scientist of Indian origin, to qualify this distinction. Har Gobind Khurana (1968), S. Chandrasekhar (1983) and Venkitaraman Ramakrishnan (2009) followed Raman’s foot prints but built their research career in foreign lands affiliated to foreign universities; hence their medals can’t be counted as India’s. In this context, it may be noted that independent India is devoid of any Nobel medal in science. Table 1 compares the number of Nobel medals in science, per capita GDP and Human Development Index of BRICS countries. India ranks lowest in HDI and Per capita GDP. While acknowledging the country of origin of the medallist, the Nobel foundation also mentions to which country and institution the person has been affiliated at the time of the award. In this count, India and Russia are the only BRICS nations with any Nobel laureate by affiliation. Russia has two medals and India has one. But for Raman, India wouldn’t have been in that list.

Table-1. Nobel medals of BRICS Countries (Source: World Bank Data)

Russia has a total of 17 medals: 12 before 1991 and 5 since then. However Russia, prior to 1991 can’t be counted among BRICS nations as until then it was a part of the super power, USSR. Out of the five Nobel medals received by Russia since 1991, two are its own by way of affiliation. Nevertheless these medals can’t be compared to the one brought home by Raman. While the post-Soviet Russia had inherited a great legacy of scientific advancement materialised by the erstwhile USSR, India had nothing of that sort. Raman’s research was largely homemade. A closer look at the medal count in table 1 reveals a fundamental issue prevailing in BRICS countries. These countries lack the ‘circumstances’ required for nurturing and leading young scientists to international recognitions like Nobel. The message they give out to the aspiring young scientist is very clear: ‘get out, if you want a medal’. Raman had clearly understood this and had the firm conviction that the only way to India’s scientific progress is to build her own science here. He spoke at the Mysore Chamber of Commerce on 18th April 1937

“If I am given a budget of ten lakhs a year for ten years and a free hand, I will solve all the problems connected with India’s scientific and industrial development, and place India in a position to produce everything from a battleship to a pin” (Uma Parameswaran, 2011)

Being a contemporary of Gandhi, Raman’s idea of self reliance in scientific research would have been influenced by the nationalist movement. How far-sighted Raman’s vision on self reliance in science was, is evident from the facts presented in table 2.

Table-2. Performance of BRICS countries in Scientific Research (Ranks within brackets) (Source: World Bank Data)

Table 2 compares the number of patent applications filed, export of high-tech scientific products and number of scientific publications from BRICS nations. China tops the list in all categories. India is in second or third position except in case of exports of high-tech products. However a comparison of the number of patent applications filed from India and that by Indians residing abroad reveals the true state of India’s scientific environment. The number of patents filed by Indian scientists from outside India is four times that those filed from India. While Brazil and South Africa share similar conditions, the case of China and Russia is different. 75% of China’s and 67% of Russia’s patent applications are filed from within those countries. This is a clear indicator, not only of the high levels of self-sufficiency these countries have attained in scientific research, but also of the fact that the number of scientists leaving these countries for research is much lesser when compared to India, Brazil and S. Africa. Raman had realised this danger in 1930s itself and had his own plans for preventing this intellectual leakage. He mentored two generations of scientists in this country.

During his tenure at Indian Association for Cultivation of Sciences, Calcutta University, IISc Bangalore, Central College and RRI, Bangalore Raman nurtured a large number of young researchers. S. Bhagavantam, Sathish Dhavan, A.S. Ganesan, G.N. Ramachandran, KS. Krishnan, Nagendranath, KR. Ramanathan, S. Chandrasekhar, A. jayaraman, PR. Pisharoty, HJ. Bhabha, Vikram sarabhai, S. Ramaseshan are to name a few, who went on to building science in this country. PR. Pisharoty speaks about the magnetic influence Raman had on his students.

“He inculcated in them (students) a capacity for long hours of work and a self- confidence that they can and should pit their brains against the best brains of the world. Under his magnetic personality, these qualities lasted at least as long as the students were with him; but alas, many of them lost these qualities soon after they moved away from his proximity. However, whenever any of them went to him, he re-generated those qualities in them through a few minutes of conversation.” (Pisharoty, 1971)

Let’s get back to the data presented in table 2. During 2010 the export of high-tech products from China was 28% of all exports of the country. In case of India it is just 7%. While China published 74,000 scientific papers India published only a quarter of it. A survey conducted by Nature in 2004 revealed that India occupies only 22nd position among countries that made impact-making scientific publications. China, South Korea and Poland are far ahead of India in this respect. India’s relative position in the world of science has declined in the last twenty years. We produce more science than before, but several more ambitious countries like China and S. Korea have outpaced us (DST, 2010). The 2010 report of Science Advisory Committee to Prime Minister of India points out that in order to contribute significantly to world science and to make an impact on it, India’s contribution to global scientific literature would have to rise to something like 10% (from the present 2% or so). Raman was a great champion of scientific writing. He is reported to have instructed his colleagues, the day before his death:

“Do not allow the journals of the Academy to die, as such journals are the only indicators as to whether science is taking root in our country or not” (Lynall, 2008)

Mary-Ellen Lynall, a researcher from Cambridge writes:

“Raman’s personal contribution to the development of scientific journals in India is astounding. When Raman entered science, there was no scientific journal of international repute in India . . . Holding positions of power does not in itself indicate strong support for Indian journals; as demonstrated by the many Indian scientists today who are associated with the editorial boards of Indian journals, yet publish abroad. Raman, however, was not in this category, writing 133 articles, 15 major book reviews and hundreds of short notices for ‘Current Science’ alone. . . Raman was truly the father of scientific publishing in India and Indian scientific publishing was undoubtedly most successful in the years when ‘Current Science’ and the ‘Proceedings’ were under his direction”

Today young scientists prefer to publish in high-impact international journals, which would fetch them international recognition and better citations. Some argue that there is nothing called Indian science and science is international. This may be true. But there is the question of identity of a scientific community. If scientists publish in a home journal, it gives identity to a scientific community. Experts say that a scientific community needs its own peer-review system to maintain its health (Lynall, 2008). Journals facilitate this.

Table. 3. Some Science and Technology indicators for select countries (Source: DST, 2010)

Table 3 compares the improvement made by India, China and S. Korea during the period from 1997 to 2006 in total number of scientific publications and percentage of high impact publications. This comparison clearly shows at what stupendous pace China’s scientific publications grew in a decade. S. Korea has also done extremely well, more so qualitatively. India has done well but not very well. The prescriptions made by Raman seventy years ago for building true science in India appear to be still relevant but not yet fully implemented. However the effect that he had left behind is still luminous, impelling and inspiring new generations of young minds. Let us hope that it would keep catalysing scientific progress in India for many more years to come.

READ A MALAYALAM VERSION IN DESHABHIMANI DAILY

References

Department of Science and Technology (2010) India as a Global Leader in Science; report of Science Advisory Council ti the Prime Minister

Lynall Mary-Ellen (2008) C.V. Raman’s work on scientific journals: legacy and lessons for Indian science. Current Science .Vol.94, No.03. p.305

Pisharoty.P.R (1971) Sir. CV. Raman as a teacher at Bangalore. Current Science No.9, p222

Uma Parameswaran (2011) C.V. Raman, A Biography. Pub. Penguin Books

J. Nagaraju: a Mémoire

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 09 Jan 2013 09:03:00 +0000

Dr. Pierre Couble

Dr. Pierre Couble

Dr. Couble, renowned molecular biologist and silkworm biologist was a close associate and friend of the late Dr. J. Nagaraju. Dr. Couble, in spite of his busy scientific engagements, has found time to write a reminiscence on his departed friend. We at 'THE SILKWORM' are honoured in publishing this reminiscence.

Dr. Pierre Couble is currently The CNRS Research Director, CNRS-Université Lyon, France. Contact him at: Pierre.Couble@univ-lyon1.fr

Dr J. Nagaraju passed away on the 31st of December 2012. All those who knew him are devastated by his sudden death. Dr Nagaraju was a passionate, inspired and imaginative scientist and a beloved friend. He brought a vast contribution to silkworm biology, in many distinct areas. His curiosity was endless, with a permanent attention that scientific progress be useful to society.

Dr J. Nagaraju started his career at the Central Sericultural Research and Training Institute in Mysore (Karnataka), as a Central Silk Board (CSB) employee. In 1989, he came to Lyon (France) for a two-year stay at the CNRS to work on the cellular and molecular genetics of the silkworm. This is when we started to work in collaboration. Back to India, he was invested by the CSB with the mission of running Seribiotech, a brand new research laboratory in Bangalore in the fast emerging field of biotechnology, aiming at blending fundamental and applied research. After the Seribiotech experience, Dr Nagaraju moved to Hyderabad in 1998 and joined the Center for Cellular and Molecular Biology (CCMB) and the Centre for DNA Footprinting and Diagnostics (CDFD) where he settled down finally. In 1997, he stayed for one year at Harvard University in the laboratory of Daniel Hartl.

Dr. Pierre Couble and Dr. Nagaraju In Durban, summer 2008

Dr Nagaraju first developed fingerprinting of the Bombyx genome by various approaches to assess the genetic diversity of the silkworm in multiple ecotypes and inbred lines. With his little team at Seribiotech, he characterized the first B. mori microsatellites, their type, abundance and polymorphism, and their potential for traceability of genetic resources. He maintained interest in repetitive DNA throughout his career and more recently developed SilkSatDB, a silkworm microsatellite data base and then InSatDb, an interactive interface to query information regarding microsatellite characteristics of fully sequenced insect genomes.

As a major silk-producing country, India is home to the mulberry silkworm but also to three other varieties of natural silks: tasar, eri and muga, unique silkworm species that feeds on specific host plants. In this field, Nagaraju pioneered the study of the diversity and of the population structure of these rare silkmoths, of dwindling culture.

His experience in the study of genome polymorphism and plasticity led him to investigate the genetic diversity of Basmati rice, a high added value product of India agriculture. By using SSR markers, he could develop rapid multiplex microsatellite marker assays for the authentication of traditional Basmati varieties, which awarded him the gratefulness of the Indian government.

In CCMC and CDFD, he also took interest in many fundamental questions. One concerned determination of sex, a fascinating paradigm owing to the myriad of sex determining primary signals among insect species, which he approached with Giuseppe Saccone (Italy). He worked at deciphering the collection of the genes carried by the Z chromosomes (in silkworm males are ZZ and females ZW) and initiated a study of the female specific chromosome W that is strongly female determining and was long thought to harbor feminizing genes. Dr Nagaraju identified such a W-chromosome linked gene, a remarkable finding since that gene may be a master contributor of the female sex. He conducted such critical work in collaboration with Kasuei Mita, Toshiki Tamura and colleagues from Japan. Unfortunately, this masterpiece will be published after his death.

Recently, Dr Nagaraju’s group and we in Lyon constructed silkworm transgenic lines which added a genetic trait that confers refractoriness to infection by baculovirus, a major pathogen in Indian sericulture facilities. The beneficial trait was introgressed into a commercial race, allowing to combine high silk productivity and immunity to the virus. This first industrial application of transgenesis illustrates the will of Dr Nagaraju to exploit genetic concepts practically. Several important traits have not yet been handled successfully in traditional breeding schemes. Dr Nagaraju always pleaded for the incorporation of modern genetic analysis in selection, which coupled with conventional breeding, allows the dissection of complex, multi-gene controlled traits. In this respect, Dr Nagaraju was a restless go-between, linking the community of the basic scientists and that of the sericulture industry.

The sad passing away of Dr Nagaraju poses the question of his successor as a guide of Indian silkworm research programmes and as a recognized international spokesperson who always worked to connect science and society.

Dr. J. Nagaraju passes away

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Tue, 01 Jan 2013 17:59:00 +0000

Dr. J. Nagaraju, noted molecular biologist and Khorana Chair at Centre for DNA Fingerprinting and Diagnostics (CDFD) passed away in Hyderabad on 31.12.2012. He was also heading the Laboratory of Molecular Genetics, Consultant Scientist of Agricultural and Processed Food Products Export Development Authority (APEDA) - CDFD Centre for Basmati DNA Analaysis and Co-Ordinator, Laboratory of DNA Fingerprinting Services. Dr. J. nagaraju had an illustrious scientific career. After obtaining Ph.D. from University of Mysore he became a Research Associate in Prof. Pierre Couble's Laboratory (Molecular Genetics), University of Lyon, France and held Visiting Scientistship in Daniel Hartl's Laboratory, Harvard University, USA. He was instrumental in setting up the Seribiotech Laboratory (Central Silk Board, Ministry of Textiles, Govt. of India) in 1992 and served as its Head till he moved to CDFD in 1998. Dr. Nagaraju has immensely contributed to silkworm genomics and genetics. His demise has caused a severe blow to the scientific world, particularly to silkworm molecular biology.

The sericulture fraternity of India should be thankful to him for laying strong foundations for seri-biotech here. At the laboratories founded by him at Kodathi, Bangalore and at CDFD Hyderabad, he had not only worked day and night, grinding tissues, running PCRs and fine tuning protocols, but also trained an impressive number of young hands at practical biotechnology. From very humble beginnings he rose to an international stature, bringing up with him India’s silkworm molecular biology, brushing shoulders with giants in the field. With his demise India’s silkworm sciences has become much poor. Sadly, the discipline will have to wait a long time to see yet another scientist of his stature to take his place.

Scenario of mulberry disease of Eastern and North Eastern India

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sat, 30 Jun 2012 11:34:00 +0000

Dr. S.K. Dutta

S. K. DUTTA, M.K.GHOSH and B.B.BINDROO
Central Sericultural Research and Training Institute,Central Silk Board, Berhampore-742101, West Bengal

Dr. Sandip Kumar Dutta is a senior scientist with Central Sericultural Research and Training Institute, Central silk Board, Berhampur, India. A PhD in Mycology and Plant Pathology, Dr. Dutta has a long innings in plant pathology related research under Central Silk Board, India. Dr. Dutta can be contacted by email : dutta_sandipkumar@yahoo.in and by telephone: +91 9735601099

Mulberry (Morus alba, L.) is the sole food of the mulberry silkworm, Bombyx Mori L. This plant, belonging to family Moraceae is a deciduous plant. Incidence of a wide variety of diseases is one of the major hindrances for sericulture activity in Eastern and North Eastern India.

Mulberry can be grown under various climatic conditions from temperate to tropical. Among the commercially exploited mulberry varieties of Eastern and North Eastern India incidence of Powdery mildew (Phyllactinia corylea), Bacterial leaf spot (Xanthomonas campestris p.v.mori), Pseudeocercospora leaf spot (Pseudocercopsora mori), Myrothecium leaf spot (Myrothecium roridum) and leaf rust (Peridiopsora mori) are predominant.
Beside reduction in leaf yield, these diseases reduce the quality of foliage considerably. Meteorological factors viz, Temparature, relative humidity, Rainfall etc. play a vital role in providing congenial circumstances for pathogenic multiplication and disease severity in different agro climatic zones. Intensity of disease may be positively or negatively correlated with meteorological variables. Generally disease spread through germination of spores, depending on leaf wetness. Leaf wetness depends on humidity, rainfall and dew. Wind is related with spore dispersal. In general scanty rainfall, low agricultural inputs and out break of pests and diseases are contributing factors for economic loss to farmer

A study was conducted in 10 states in the north eastern parts of India to assess Severity (PDI) of different diseases were in different climates round the year, to arrive at a set of disease calendars. Seven calendars are presented here as an outcome of the study. We believe that the calendars will be useful to farmers by enabling them to anticipate disease outbreak and take up necessary prophylactic measures against them. The diseases under study are Bacterial Leaf Spot (BLS), Pseudocercospora leaf spot (PLS), Leaf rust (LR), Myrothecium leaf spot (MLS) and Powdery mildew (PMLD).

The states and locations where the study was conducted are furnished in table 1. Table 2 , gives the disese calendar for the five diseases in various states in north eastern India. Tables 3 to 7 give the disease calendar for each disease in locations where the incidence is significant.

Table-1: The States and locations where the study was conducted

Table 2: Disease calendar for Eastern and North Eastern India

Table 3: Disease calendar for Bacterial Leaf Spot

Table 4: Disease calendar for Eastern and Myrothecium Leaf spot

Table 5: Disease calendar for Eastern and North Eastern India

Table 6: Disease calendar for Pseudocercospora leaf spot

Table 7: Disease calendar for Leaf Rust

APPLICATIONS OF INSECT GROWTH REGULATORS IN SERICULTURE AND AS FOOD SUPPLEMENTS

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Tue, 19 Jun 2012 11:50:00 +0000

A. Banerji

School of Biotechnology, Amrita Vishwa Vidyapeetham, Amritapuri, Kollam Dist. 690525

Dr. Asoke Banerji

Dr. Asoke Banerji is Distinguished Professor at Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kerala. The main thrust of research activities of Professor Banerji’s group has been directed towards emerging areas of natural product chemistry and Biotechnology. He gave a new direction to the natural product research by purpose-oriented investigation of the plant extracts following reverse pharmacological approach. During the course of research work, an array of natural products belonging to different groups (medicinal as well as other activities) were isolated and characterized. Professor Banerji has several patents to his credit. In addition to medicinal compounds, he has contributed to other areas also such as natural dyes, biopesticides, bioremediation, biotransformation, high-value agrochemicals. As a result of screening of indigenous flora, several insect growth regulators (IGR), both phytoecdysoids and juvenoids, were isolated and characterized. Processes for their preparation in commercial scale have been developed. Some of the isolated phytoecdysoids are being used in the commercial formulations for use in sericulture isolated. A list of selected publications of Dr. Banerji, provided at the end of this article will give the readers an idea about the span of his work in phytochemistry.

SUMMARY

Indigenous plant sources of insect growth regulators (both phytoecdysterones and juvenoids) have been identified. Viable methods for their commercial preparations have been established. Optimum doses and timing of application of IGRs for sericulture determined. In addition to sericulture, phytoecdysterones are also useful as food supplement (nutraceuticals) or for fortifying existing health foods/supplements and important biochemical tool for genetic engineering.

INTRODUCTION

Insect growth regulators (IGRs) such as juvenile and moulting hormones or their analogs (juvenoids and ecdysoids) when used judiciously, have been found to be useful in sericulture industry. In addition, ecdysoids also show a variety of other uses such as insecticidal, as biochemical tool in gene expression studies, as wound healing and anabolic agents ( body building agents with enhancing protein synthesis), as nutraceuticals and cosmetics (hair growth) IGRs occur in insects in very small amounts and are not practical source for these phytochemicals. However, with the discovery of their occurrence in significant quantities in some plants, IGRs and their analogs became easily available in substantial amounts. As a result, many new bioactivities of ecdysoids and juvenoids were discovered. Besides use in sericulture, they have found applications in apiculture and aquaculture (prawns). Ecdysoids show remarkable anabolic activities in human and are very much in demand as nutraceuticals (food supplements) including body building agent. Realizing the economic potential of IGRs, bioprospection for these compounds from indigenous plant sources was undertaken. Our survey indicated that a large number plants belonging to different taxa contain IGRs. Our focus was on plants showing insecticidal activities and two main IGRs, viz. ecdysteroids (ecdysterone analogs) and juvenoids (juvenile hormone analogs). Suitable bioassays for each of the activities were established and about 500 plants were screened for IGRs. This resulted in the discovery of several sources of IGRs from different geographical locations.

IGRs IN SERICULTURE

India is one of the largest silk producing countries. Mulberry silk accounts for most of the silk produced in India. Three other species namely, Eri, Tasar and Muga are mainly grown in the north-eastern India. India is also one of the major consumers of silk. Sericulture, the agro-industry of cocoon and silk production is the source of income of several marginal farmers of India. However there is a shortfall of 7000 metric tonnes of silk fibre within the country. The silk production in India needs improvement in quantity as well as quality compared to other silk producing countries. Central Sericulture Research and Training Institute (CSRTI), Mysore has been involved in the improvement of the mulberry seri-technology in a holistic way. However there is considerable scope of improving the varieties of silk produced in north eastern India.

Sericulture is a labour intensive agro-based industry which provides additional income to marginal farmers. Substantial part of labour in sericulture management goes in the picking up of the mature larvae for mounting. The duration of mounting period is quite variable. Duration of the moulting from beginning to end may vary between 48-72 hours. This implies that labour must be available continuously all through the period (day and night) of moulting. Application of exogenous ecdysoids helps in the synchronization and reducing the time for spinning. Its application hastens the maturation without affecting the quality and yield of silk. Application of ecdysoids synchronizes and shortens the period of moulting to 18-24 hours. This helps considerably in the management of sericulture and reduces the cost of labour. Hastening the moulting period also contributes in the reduction in the consumption in the feeding of mulberry leaves without affecting the yield of silk fibre. Use of juvenoids on the other hand, tend to keep the fifth instar silkworm young by extending the larval period and increasing the silk secretion. It postpones the spinning stage by few hours. Thus when applied judiciously, IGRs can contribute significantly in increasing the silk production.

PHYTOECDYSOIDS IN SERICULTURE

Sampoorna-A commercial phytoecdysoid

Ecdysoids and their analogs (called phytoecdysones) occur in significant quantities in many indigenous plant sources. A simple bioassay based on sclerotization of house fly last-instar larvae was developed. Several hundred extracts from plants were screened following this bioassay. Initiation of the sclerotization within 24 hr of treatment was indicative of presence of phytoecdysoids (PEC). PECs were isolated following activity- guided fractionation of plant extracts and active principles were isolated . More recently, non-biological methods based on chromatographic, spectroscopic and LC/MS methods have been developed in our laboratory for quick identification and quantification of PECs and their analogs. A convenient method for their isolation has been developed (patent pending). Results of our screening of plant extracts show that PECs have wide occurrence in plant kingdom. In collaboration with CSRTI, Mysore, optimum time and dose of application of PEC have been established. Commercially viable sources of PECs have been discovered for possible application in sericulture industry and other applications such as food supplement (nutraceuticals). Commercially viable process for preparation of PEC in large scale has been developed. Application of PEC in the farmers fields have established that there is considerable savings in labour cost . In countries like China, Japan, France, IGRs are in regular use in sericulture.

PHYTOECDYSOIDS AS NUTRACEUTICAL

Amrutha- a commercial phytoecdysoid

Formulations with PECs as active constituents have found use as health promoting products. PECs do not have adverse effects on human health even at gram levels. They show anabolic activities and are useful constituents in many commercial food preparations. They are useful adjunct for fortifying many of the currently used beverages and food supplements. They are popular in many countries as natural body building agents. In addition they show a variety of biological applications such as molecular switches, and have potential use in researches on gene expression and related studies.

JUVENOIDS (JH)

The juvenile hormone (JH) activity of plant extracts/isolated compounds were determined using 5^Th instar nymph of red cotton bugs (Dysdercus koenigii). Juvenoids are analogs of insect juvenile hormones. Several compounds, showing JH activities have been found in many common plants. Application of JH’s to silk worm prolongs the larval period. Synthetic JH analogs are in use in sericulture industries in countries such as Japan, China. There is no commercial Indian source for juvenoids.

Samrudhi- a commercial juvenoid

Imported synthetic JH analogs are expensive. Hence there is a need for identification of cost effective JH formulation for improving silk productivity. Several sources JH analogs from plants have been identified in our laboratory and isolation and characterization of the active principles have been carried out. Eco-friendly economic process for their preparation has also been developed by our laboratory. Based on existing information, it can be predicted that use of IGRs will give a boost to sericulture industry.

PROSPECTS OF USE OF IGRs IN INDIA

IGRs are in use in many countries in sericulture, aquaculture and apiculture. They are in great demand for body building formulations and cosmeceutical preparations. Indian farmers have realised the beneficial effects of IGRs and some preparations have appeared in the market. As a result of our studies several plant –based sources for PECs and JHA have been discovered. Protocols for their application have been developed. Detailed information on the sources, quality control and applications of indigenous IGRs is available for commercial exploitation. Entrepreneurs interested in the commercial exploitation of these products for sericulture, food supplement or as biochemical tool are welcome to contact me at Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham. banerjiasoke@gmail.com or mobile +91 9895527851.

Select list of publications of Dr. A. Banerji

1. A. Banerji, G. J. Chintalwar and M. S. Chadha, Isolation of Ecdysterone from Indian Plants, Phytochemistry, 10, 2225 (1971)

2. A. Banerji and G. J. Chintalwar, Phytoecdysones and Flavonol Glycoside from Sesuvium portulacastrum, Indian J. Chem.,9, 1029 (1971).

3. A. T. Sipahimalni, A. Banerji and M. S. Chadha, Biosynthesis and Interconversion of Phytoecdysones in Sesuvium portulacastrum L. J. Chem. Soc. Chem. Commun., 692 (1972).

4. A. Banerji and G. J. Chintalwar, Biosynthesis of Bakuchiol, A Meroterpene from Psoralea corylifolia Phytochemistry, 22, 1945 (1983).

5. A. Banerji and G. J. Chintalwar, Biosynthesis of Bakuchiol from Cinnamic and p-Coumaric acids. Phytochemistry, 23, 1605 (1984).

6. N. K. Joshi, K. M. Lathika, A. Banerji and M. S. Chadha, Effects of Plumbagin on Prothoracic glands of Dysdercus cingulatus in "Endocrinological Frontiers in Physiological Insect Ecology" (Eds. F. Sehnal, A. Zabra and D.L. Denglinger) Technical University Press, Wroclaw (Poland) pp. 69 (1988).

7. N. K. Joshi, K. M. Lathika, A. Banerji and , M. S. Chadha, Effect of plumbagin on Growth and Development of Red Cotton Bug, Dydercus Koenigii, Proc. Indian Natn. Sci. Acad., B54, 43 (1988).

8. V. Ramakrishnan, G. J. Chintalwar and A. Banerji, Environmental Persistance of Diallyl Disulphide, an Insecticidal Principle of Garlic and its Metabolism in Mosquito, Culex pipens Quinquifaciatus Chemosphere, 18, 1525 (1989).

9. A. Banerji and G. J. Chintalwar, Fate of Leucine in the Biosynthesis of Bakuchiol, a Meroterpene from Psoralea corylifolia. Indian J. Biochem. Biphys., 26 394 (1989).

10. D. L. Luthria, V. Ramakrishnan, G. S. Verma, B. R. Prabhu and A. Banerji, Insect Antifeedants for Atalantia racemosa. J. Agric. and Food Chem. 37, 1435 (1989).

11. 57. N. K. Joshi, K. M. Lathika, V. Ramakrishnan, A. Banerji and M. S. Chadha, Plumbagin-Induced Inhibition of Ovary Development in Dysdercus cingulatus. in "Regulation of Insect Reproduction IV', Eds. M. Tonner, T. Soldan, B. Bennettova, Academia Publishing House of the Czechoslovak Academy of Sciences Praha, pp. 287 (1989).

12. A. Banerji, Radiosynthesis of 35S-Labelled Bioactive Compounds and their Metabolics, Proceedings of national symposium on nuclear techniques in the study of pesticides in food agriculture and environment, The University of Acultural Science, Hebbal, Bangalore Feb. 8-10, 1989.

13. A. Banerji, Insect control by biotechnical procedures - Lessons from plant kingdom, in “Insect Chemical Ecology” (Ed. I. Hrdy), Academia Praha, pp. 235.

14. A. Banerji, Biotechnical Potential of Natural Products, Bioelectrochemistry and Bioenergetics, 27, 105 (1992).

15. A. Banerji, Insect Plant Interactions: Natural Insect Control Agents, Recent Advances in Insect Physiology and Toxicology, 41, Ed. G.T. Gujar, Agricole Publishing Academy, Delhi, (1993).

16. A. Banerji in Role of Allelochemicals in the Ecodynamics of Insects and Plants. "Biochemical Perspectives in Chemical Ecology of Insects", ed. T. N. Ananthakrishnan, Oxford & IBH Publishing Co., New Delhi, 000 (1995).

17. G. R. Shivakumar, K. V. Anantha Raman, K. Venkata Rami Reddy, S. B. Magadum, R. K. Datta, S. S. Hussain. A. Banerji and S. K. Chowdhury, Effect of Photoecdysteroids on Larval Maturation and Economic Parameters of the Silkworm, Bombyx mori., Indian J. Seric., 34, 46, (1995).

18. G. R. Shivkumar, K.V.A. Raman, S.B. Magadum, R.K. Datta, S.S. Hussain, A. Banerji and S.K. Chowdhary, Effect of Phytoecdysteroids on the Spinning, Cocoon and Reeling Parameters of the Silkworm, Bombyx mori L., Allelopathy Journal, 3, 71, (1996).

Note: To read another related article on phytojuvenoid published earlier in this journal, CLICK HERE

A New Highly Productive Silkworm Sex-Limited Pure Genetic Line

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 15 Feb 2012 05:34:00 +0000

H.S. Homidy, D. Gahakwa, A.N. Papaskiri and A. Rutayisire

Professor H.S. Homidy

Professor Homidy Khomid Soky (HS. Homidy) is International Expert on program development of sericulture, of the Ministry of Agriculture and Animal Resources, Rwanda (IFAD/PDCRE/RHODA/RAB). His research interest in sericulture are wide and varied such as: breeding of silkworm, biochemistry, physiology, technologies of silkworm hybrid (F1) egg productions, silkworm rearing, productions of cocoons and post-harvest, disease control, maintenance of mulberry plantations, mulberry crop protection etc. During his 23 years of research career he has held important positions as deputy director on research National Research Institute of Sericulture, Uzbekistan, Vice-minister Ministry of Silk Industry republic of Uzbekistan, Director of National Research Institute of Sericulture, Uzbekistan, Manager of scientific technological centre of Uzbek Scientific Research Institute of Sericulture etc. He has to his credits two books, 61 research papers 20 PhD theses and three patented inventions. Professor Homidy is the Vice president of the Black, Caspian Seas and Central Asia Silk Association (BACSA).
He may be contacted at: Email: khomid_khomidy@mail.ru , Republic of Rwanda Kigali , Tel: +250783280724

Abstract

Generation of highly productive sex – limited pure genetic silkworm lines remains interesting both in theoretical and in practical aspects using the practice of sericulture to allow simplified production of highly heterocyst silkworm egg hybrids.

During process of selection on preservation of characteristics and adaptation to new environment conditions of silkworm breeds, with the breed named Progress (Uzbek selection - Japanese type), the sixth generation silkworm larvae with different skin color were generated. The new silkworm larvae genetic pure line revealed sex-limited characteristics. Their distinctive feature consist of: silkworm larvae having marking on the first and fourth segment are female and having marking in first to fifth segments (type multi-lunar) are male larvae. ‘Trialson’ the new genetic pure line up to the fifth generation has shown stability of their phenotypic signs and essential differences between females and males. Thus the balance of sex at larvae stage of 1 ♀♀: 1 ♂♂ was achieved. The new genetic pure line is superior in viability of pupation (92,64%), weight of a cocoon (2,48 g) and cocoon shell (0,567 g). Fresh cocoons yield average attained 44,46 kg/box and accordingly with excellent raw silk yield (7,515 kg/box).

Keywords: Sex – limited silkworm pure genetic line, heterosis, hybrids, sexual chromosomes, morphological signs.

Introduction

Mulberry silkworm (Bombyx mori L.) became the first object on which to practically solve the problem of artificial sex regulation. The main reason for using sex – limited silkworm lines is to make easier and more effective, the process of silkworm egg production especially in terms of sex discrimination. The first attempts to create sex-limited silkworm breeds were made by Tichomirov (1891), followed successfully by other researchers like Tazima (1944), Hasimoto (1948), Astaurov (1972), and Lee at al. (1988). The first silkworm strain, having marked female larvae and plain male was created by Tazima (1944) by treatment of newly laid silkworm eggs with X-rays and translocation of the P+ allele and its connection with the sex chromosome W. Later, using the same method Hasimoto (1948) managed to create a new sex-limited breed having zebra female and plain male larvae. By this method, the initial material used was sex limited races that were crossed with other races having plain larvae or yellow eggs. After that the hybrid population was maintained by batch rearing for four generations and with inside batch mating (inbreeding). Strunnikov (1969) expanded the studies, directed toward the creation of marked differentiation by sex at the egg stage but also with sufficiently good viability. The main distinctive special feature of these lines is that females are developed from the dark eggs while males arise from the bright eggs. On the basis of translocation lines, two breeds, one which is characterized by the oblong form of cocoon, and another with cocoons that are rounded, were created. Concerning the sex-limited character of cocoon color, it is established, that the female cocoon is yellow and the male white. It permits an easy sex-discrimination and the male cocoon can separately be reeled to produce high-grade silk (Chen, 2002).

After discussion of such impressive results on silkworm sex regulation at different stages using X-ray, it was possible to think, that the problem is completely resolved, but however in the literature there is no information on any research or discovery of natural mutation in sex marking of silkworms. In these circumstances, our research was to adapt silkworm breeds delivered from different geographical zones to sub - equatorial climate of Rwanda, to study phenotypical changes including possibilities of occurrence natural mutation in these breeds.

Materials and methods

Study area

This study was conducted at the sericulture unit at the Rubona Research Station, previously under the Rwanda Agricultural Research Institute. Rubona station 2.26 (2° 15' 49 S; 29.81 (29° 48' 27 E) is located in the mid-altitude agro-ecological zone in southern Rwanda, 125 km from Kigali, the capital city. The station has a subequatorial climate and is located at high altitude (1700 m over sea level), with an annual average temperatures around 18-21 °С and rainfall between 1300 -1800 mm. The dry season start from June up to August – September.

Study design

We used a completely randomized design where all the silkworm breeds available were subjected for research of adaptability reaction to new sub - equatorial climate of Rwanda. The study focused on any possible effect of transformation of the silkworm breeds, particularly on revealing mutant genetic lines.

Process that transformed the silkworm

During selection on adaptation of silkworm breeds delivered from different geographical zones to new environment conditions, with breed named Progress (Uzbek selection) Japanese type, in the sixth generation of selection, some silkworm larvae with different skin color were revealed. For improvement and preservation of cleanliness of the silkworm sex-limited breeds, the moderate and remote related breeding – i.e. inbreeding V-VI degree was applied. Selection was carried out based on phenotypical signs of sex-limited silkworms. More than 150 individual families were prepared, but after their detailed analysis, only 105 families were saved. After results on hatchibility of layings, 50 best families were taken for rearing by using Homidy et al., (2001) silkworm rearing procedure.

Data analysis method

Data collected from our work was analysed using common-method of statistical analysis of qualitative and quantitative data (Tabachnick, B.G. & Fidell, L.S. 2007).

Results and discussion

The idea of Serebrovsky (1935) consisted to use an artificial method, particularly, use of X-ray radiation, to get the silkworms sex-limited. The target was to get male and female silkworms with morphological differences distinguishable at an early stage of development. This phenomenon is due to the genes translocation. The genes responsible for morphological signs are located on sex chromosomes.

New pure silkworm sex-limited pure line GH-02

During our research work on sex-limited silkworm, mainly using the selection technique, we produced a new genetic pure line that has code named GH-02. This new genetic pure line

revealed sex-limited traits in the larvae stage as well. The distinctive feature of this line consist of the silkworm larvae having carpet type markings on segments, typical characteristics of females; and silkworms having usual type marking on their segments, characterizing male larvae . Breeding and selection studies on the new genetic pure line GH-02 up to the fifth generation showed stability on the phenotypic signs, which are essential differences between females and males. Thus, the balance of sex at larvae has now been stabilized at the ratio of 1 ♀♀: 1 ♂♂ (Table 1).

Cocoons of New pure silkworm sex-limited breed (GH-02)

The analysis of the obtained indicators on phenotypical signs of new genetic pure line GH-02, shows that viability of pupation rate of 90,24±0,3 - 95,04±0,2 %, weight of a cocoon-2,80±0,02-2,16±0,01g, cocoon shell -0,582±0,1-0,553±0,2 g and percent cocoon shell-21,0±0,01 - 25,6±0,02%. Fresh cocoons yield by 1 box silkworm eggs an average makes 44,46 kg, thus cocoons yield at females reaches 49,49±3,2 kg/box. The essential difference was not observed in color of female and male cocoons, thus essential differences were revealed in their technological parameters, like filament length-1242±6,7 - 1287±5,3 m, good cocoons reelability (average) 87,5 % and excellent raw silk yield 7,32±1,2 - 7,71±1,5 kg/box.

Table 1. Testing new silkworm six-limited pure line GH-02

Conclusion

It is important to understand that sericulture is focusing on deducing new highly productive breeds with improved raw silk yield and disease resistance. During the process of research on adaptability response of silkworm breeds delivered from different geographical origins to local condition, for the first time in Rwanda, at larval stage it was discovered a new sex limited genetic line of silkworm. This new genetic pure line (code named GH – 02) had showed to be disease resistant and highly yielding in terms of raw silk with good technological parameters of filament. The difference was significantly observed in body coloration during 4th and 5th instars larval stage, in female carpet coloration appeared while in male usual coloration appeared and thus it was easy to make separation according to sex, they can be used for production of 100% silkworm hybrid eggs. The reason of occurrence of this sexual segregation could be natural mutation, attributable to the geographical location of our scientific laboratory (1700m over sea level).

References
Tazima Y. (1944) Studies on chromosome aberrations in the silkworm. II Translocation involving second and W-chromosomes //Ibid. N12. Р.109-181.

Hasimoto H. (1948) Sex-limited zebra in X-ray mutation in the silkworm. //J.Sericulture Japan. 1948, Р.16.

Astaurov B.L. (1972) Prospect of animal sex regulation //J. Nature.№2. P.48-57.

Lee S., Kim S., Kim K., Lee S., Lee H., Lee Y. (1988) Induction of sex-limited cocoon color character by translocation of yellow blood gene Y(TT -25.6) on to W chromosome by gamma irradiation in silkworm. Bombyx mori. //Korean J. of Breeding, 21(3), P.219-223.

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Bio-pesticides and Bio-fertilizers for sustainable sericulture

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sun, 28 Aug 2011 15:04:00 +0000

Dr. Dayakar Yadav

Dr. Dayakar Yadav is senior scientist with Central Silk Board (CSB), India. After obtaining PhD in Mycology and Plant Pathology in 1980, he had a long and fruitful research career with reputed organizations in India such as Karnataka State Forest Department, University of Agricultural Sciences, Bangalore, Karnataka State Sericulture Research and Development Institute, Central Sericulture Germplasm Research Institute (CSB), Central Sericultural Research & Training Institute, Central Silk Board. He has published more than 60 research papers in reputed journals and attended overseas training programs in Japan and China.

Introduction

The 20^th century has witnessed a slow but steady emergence of bio-pesticides and bio-fertilizers as potential supplementary and environment friendly inputs to their chemical counterparts. With the documentation of nearly 2500 bioactive plant species, over 1000 protozoa pathogenic to insects, 700 species of invertebrates and an array of other micro and macro-bioagents; their role in future crop protection cannot be ignored. Likewise; bio-inoculants or bio-fertilizers, primarily the nitrogen fixers and the phosphate solubilizers, hold vast potential in meeting plant nutrient requirements while minimizing the use of chemical fertilizers. Furthermore, successful exploitation of genetic engineering technology (metagenomics) to incorporate non-native pesticide producing genes into crop plants has added another dimension to the potential use of these inputs in agriculture. Currently, Asia-Pacific countries are the leading advocates of bio-pesticides and bio-fertilizers for sustainable agriculture.

Agriculture practices and its impact on the earth

In the beginning of 21^st century, agriculture accounts for the major share of human use of land. Pasture and crops alone taking up 37 percent of the earth's land area and over two-thirds of human water use is for agriculture (in case of Asia it is four-fifths). Crop and livestock production have a profound effect on the wider environment. They are the main source of water pollution by nitrates, phosphates and pesticides, also the major source of the greenhouse gases methane and nitrous oxide and contribute on a massive scale to other types of air and water pollution. The overall external costs of all three sectors can be considerable. However, the long-term consequences of these processes are difficult to quantify. If more sustainable production methods are used, the negative impacts of agriculture on the environment can be attenuated. Indeed, in some cases agriculture can play an important role in reversing them, for example by storing carbon in soils (i.e., organic carbon) enhancing the infiltration of water through bio-fertilizers and bio-pesticides.

Role of Fertilizers and pesticides in sustainable environment

Concern has also grown in recent years that the use of fertilizers, particularly inorganic fertilizers, can lead to serious environmental consequences. Environmental contamination of this type, however, is largely a problem in the developed world and a few regions of the developing world. As fertilizers make up a small share of the total production costs in many developed countries, farmers often apply fertilizers in excess of recommended levels in order to ensure high yields. Over application of inorganic and organic fertilizers is estimated to have boosted nutrient capacity in the soil by about 2000 kg of nitrogen, 700 kg of phosphorus, and 1000 kg of potassium per ha of arable land in Europe and North America during the past 30 years. Such oversupply of nutrients can lead to environmental contamination, which often has negative consequences for humans and animals.

Pollution of groundwater by agricultural chemicals and wastes is a major issue in almost all developed countries, its use efficiency has to be improved or use alternate source of manures. Though the current use in many developing countries is very inefficient, China which is the world's largest consumer of nitrogen fertilizer, up to half the nitrogen applied is lost by volatilization and another 5 to 10 percent by leaching. Nitrogen synthetic fertilizers are considered the most detrimental to the environment, causing leaching and runoff that freshwater habitats and wells. Nitrogen synthetic fertilizers are a major contributor to increased N2O emissions, which are 300 times more potent than CO2 as greenhouse gas, which is ominous for global warming as synthetic fertilizer use is forecasted to increase roughly 2.5 times by mid-century.

Insecticides, herbicides and fungicides are also applied heavily in many developed and developing countries, thus polluting the fresh water resources with toxic and other poisons that affect humans and many forms of wildlife. Pesticides also reduce biodiversity by destroying weeds and insects and hence the food species of birds and other animals.

Over the past 3 to 4 decades, usage of insecticides show signs of decline, both in developed countries especially France, Germany and the United Kingdom and in a few developing countries, such as India. In contrast, herbicide use continued to rise in most countries. As concern about pollution and the loss of biodiversity grows, future use of pesticides may grow more slowly than in the past. The future is likely to see increase use of "bio- pesticides and ecological methods of disease and pest control.

A pesticide of biological origin like viruses, bacteria, pheromones, plant or animal compounds is known as bio-pesticide. They are highly specific affecting only the targeted pest or closely related pests and do not harm humans or beneficial organisms while chemical pesticides are broad spectrum known to affect non-target organisms including predators and parasites as well as humans. The striking feature of bio-pesticides is environment friendliness and easy biodegradability, thereby resulting in lower pesticide residues and largely avoiding pollution problems associated with chemical pesticides. Further, use of bio-pesticides as a component of Integrated Pest Management (IPM) program can greatly decrease the use of conventional (chemical) pesticides, while achieving almost the same level of crop yield. However, effective use of bio-pesticides demands understanding of a great deal about managing pests especially by the end users.

In terms of production and commercialization also bio-pesticides have an edge over chemical pesticides like low research expenditure, faster rate of product development as well as flexible registration process. The global weighed average consumption level of bio-pesticides is approximately 1 kg/ha. With the global organic farming area comprising about 24 million hectares, global bio-pesticide consumption is thus estimated at about 24 million kg. The bio-pesticide market is growing very rapidly, in 2005 it accounted for about 2.5% of the total pesticide market, which was merely 0.2% during 2000. This share is expected to a level of about 4.2% by 2010 while the market value is estimated to reach more than US$ 1 billion (Source: BCC research). However, the overall growth rate of bio-pesticides is estimated to be about 10% per annum for the next 5 years.

Research experiences towards sustainable Sericulture development

The Sericulture-based Integrated Farming System Management (IFSM), Integrated Nutrient Management (INM) and Integrated Pest Management (IPM) programmes are farmer-centered and farmer-participatory aimed at promotion of eco-friendly approaches for sustaining productivity and also optimization of resources utilization. These two projects were implemented in Andhra Pradesh, Tamilnadu and Karnataka states during 2002 to 2007. Under these projects, a number of technologies were evolved towards sustainable sericulture which can be translated to other crops. The technologies developed were of integrated nature and cost effective serving the purpose of eco-friendliness, sustainable development and reduction in cost of production in silk.

More poor people depend upon sericulture for their livelihood. Poverty alleviation necessarily demands increased sericulture productivity, which is a largely a function of 'technology'. Absence of technological intervention would lead to increased depletion of natural resource base. Poverty subverts efforts to introduce sustained sericulture in ways detrimental to the environment. This would lead to a decline in sericulture production potential, and sustaining capacity of sericulture would also decrease. With the ever-increasing population poverty gets perpetuated widely and deeply, furthering environmental degradation.

'Silk and Milk'

Karnataka, amply termed as silk bowl of India, from three southern states around 1.4 lakh ha. of mulberry, wherein approximately 42 lakh MT of annual production is estimated. The wastage (bed refusal) of silkworm rearing activity is used as cattle feed; silkworm litter or faucal matter as organic manure; pupae for extraction of oil / feed for poultry etc. One hectare of mulberry garden can produce about 25- 28 tones of mulberry leaf year from which 1200- 1500 kg of cocoons are produced. During this activity, about 20% (750-10000 kg/ha/crop) of leaf and/or twigs which is considered as bed refusal is fit to use as fodder for cattle. Bed refusal (uneaten leaves and tender stump) produced during rearing is effectively used by the farmers to rear cattle. It constitutes about 50% of the fodder requirement of cattle. Further, the bed refusal and tender stumps produced out of one hectare of mulberry is almost sufficient for 7 -8 cows. Apart from this, around 5% of the mulberry, which will either be soiled or unfit due to over maturity, can be used as fodder to the cattle. Rearing of eight cattle along with silkworm rearing will in turn meets the FYM requirement of one hectare of mulberry plantation. Valuable FYM will also be produced at the farm itself. Mulberry leaf stalk/stump forms the low cost/no cost alternative fodder for the cattle. By and large it is important that dairy animals have good appetite and mulberry leaf is palatable and the animal eats it very well.

Soil Health

Proper soil management without impairing soil health is the prerequisite for achieving higher productivity in sericulture. The situation has created a renewed interest in the biological transformation of sericultural farm wastes including all organic wastes into valuable manures which can be profitably used in the mulberry fields for the cost-effective production of mulberry leaves. This nutrient-rich compost is a better supplement for farmyard manure, the cost of which is escalating day by day due to shortage of cattle dung.

Integrated Plant Nutrient Supply

Azotobacter

Heavy use of nitrogen started up showing in increased nitrate concentration in underground waters in states like Maharashtra and Punjab. Due to these alarming signals, Integrated Plant Nutrient Supply (IPNS) has become a sustainability concept. IPNS involves meeting a part of the nutrient need of crops by organic manures, crop residue, green manures, dual-purpose legumes and bio-fertilizers. The need for IPNS was suggested by long-term fertilizer experiments on wheat. Application of N alone reduced the yield of wheat to zero after 13 years. Application of P along with N extended it to 22 years but in NPK plot some yield was obtained even after 22 years.

However, plots receiving a part or all nutrients through FYM not only maintained but also recorded a gradual increase in crop yield over years. Combined application of FYM and inorganic fertilizer was the best.

Bio-fertilizers: In recent years, use of bio-fertilizers holds much promise to improve the yield of crops. Bio-fertilizers sustain soil fertility resulting in increased crop yield without causing any environmental, water, or soil hazards. Out of many microorganisms, which are identified as biofertilizers, Azotobacter chroococcum, Azospirillum brasilense, A. lipoferum, Phosphorus Solubilizing Bacteria (PSB) and Vesicular Arbuscular Mycorrhizae (VAM) have proved to be beneficial in mulberry nutrition.

VAM

VAM

VAM in root cell

VAM fungi in association with higher plants play an important role in phosphorus nutrition and increase plant growth and yield. Application of phosphorus @ 30 kg/ha/year as Mussorie Rock Phosphate (MRP) with Glomus mossae inoculation significantly increased the cocoon yield. Moreover, cocoon quality due to application of phosphorus @ 30 kg/ha/year in the form of MRP with G. mossae and G fasciculatum inoculation was statistically at par with plant receiving full dose of phosphorus (@ 120kg/ha/year) without VAM inoculation. Thus curtailing 75% of phosphorus application in mulberry cultivation and reduce of cost of cultivation. Combined inoculation of VAM with diazotropic Azospirillum brasileAdd captionnse yields more mulberry leaf biomass with high nutrient level than inoculation of individual organisms.

Phosphobacterium

Phospho bacterium

Similarly to VAM and PSM the Phosphobacterium when applied to the soil, it solubilizes the insoluble phosphorus in the soil to make it available to the plants for absorption. This helps in efficient use of Phosphorus and save application of Phosphorus. Many of the cultivated soils contain high amount of total phosphorus but availability is limited due to insoluble forms. Only water-soluble phosphorus is useful for the crop plants. Many bacteria are capable of solubilising insoluble soil phosphorus, of which the role played by Phosphorus Solubilizing Bacteria - Bacilus megatherium var phosphaticum is significant.

Organic Manures

With a view to minimize the use of chemical fertilizers, farmers are able to produce different organic manures and apply as part of IPN system. Recycling of Sericultural Farm Wastes as Compost: It was established that various composts prepared out of sericulture farm wastes on mulberry revealed that application of compost prepared out of silkworm rearing wastes @ 20 MT per hectare per year or application of recommended dose of farm yard manure (20 MT per hectare per year) and chemical fertilizers also produced same quantity of leaf as against the conventional farm yard manure and chemical fertilizers. Two years crop data showed significant increase in leaf yield (61.5 tonne/ha) with application of compost @ 4.5 tonne/ha/year in conjunction with full dose of chemical fertilizers. Compost application @ 4.5 MT/ha/year (Prepared from silkworm rearing waste mixed with biogas spent slurry) + 300: 120: 120 NPK kg/ha/year produced a leaf yield was 57.8 tonne /ha/year. The study indicates that the compost and vermi-compost produced out of sericulture wastes are qualitatively superior over FYM.

Fortification of Vermi-compost

Fortifications carried out by blending the sericultural wastes with microbial inoculum - Azotobacter, phosphate solubilizing microorganisms (PSM) and add rock phosphate and single super phosphate. The process of vermi-composting of sericultural wastes (200 kg/trench) was carried out by introducing a mixed culture of juvenile earthworms Eudrilus eugeniae, Eisenia fetida and Perionyx excavatus @ 500 grams per trench. The chemical analysis of vermi-compost had organic carbon content ranged from 9.15 to 10.65%. NPK contents (2.45%; 1.75% and 1.17% respectively) was maximum in Semi decomposed sericultural farm wastes fortified with both S.S.P. and R.P. @ 12.5 kg each/MT of wastes and by inoculating with Azotobacter and P.S.M. Each cycle of vermi-composting was completed in 60 days compared to all other treatments.

Green Manure Compost

A large number of leguminous crops are used for green manuring in South India. Daincha (Sesbania aculeata), sunnhemp (Crotalaria juncea), wild indigo (Tephrosia purpurea), indigo (Indigofera tinctoria) and Pillipesara (Phaseolus trilobus) are the most popular crops with farmers. A number of other leguminous crops like cowpea, lablab, red gram; Crotalaria striata, etc., are also to able to fix atmospheric nitrogen and do not necessarily depend on the nitrogen in the soil. The phosphorus present in green manure is in organic combination and becomes available for use by mulberry in the succeeding harvests. Green manure decomposes easily without leaving much of the residue in the soil. The amount of humus added to the stock already in the soil is negligible. In this respect it is different from farm yard manure. If, however, the green manure crop is allowed to mature and is ploughed in, it decomposes slowly and some humus is added to the soil.

Pesticides of Plant Origin

One of the viable alternatives to chemical pesticides is the development and use of better botanical pesticides, which are environmentally safe, effective against pests, easy, and economic. As plants and insects have co-evolved over millions of years, they have accumulated specific secondary plant chemicals (SPCs) to counteract the insect damage. These bioactive chemicals include insecticides, anti-feedants, Insect Growth Regulators (IGRs), juvenile hormones, ecdysones, repellents, attractants, arrest ants, etc. Hence, plants are thought to be an important alternative source for chemical pesticides. Over the years more than 6000 species of plants have been screened and nearly 2400 plants belonging to 235 families were found to possess significant biological activity against insect pests.

Towards sustainable environment, health and development certain innovative technologies have been developed recently to control root rot diseases caused by Rhizoctonia bataticola (anamorph of Macrophomina phaseolina) on crops like mulberry, carrot, banana etc., it is well known that the soil borne pathogens cause severe damage to crops especially in tropical belt where the environment is suitable for the pathogen to survive and damage the host plants and complete their life cycle. A novel method was developed using plant bio-formulations, which are anti-fungistatic, and inhibitor of root rot fungal pathogen in soil. Some of the plant species, which are known to inhibit growth of fungus, like Guizotia abyssinica (L. f.) Cass. (ramtilla), Azadirachta indica A. Juss. (neem), Brassica juncea (L.) Czern. (India mustard) are inhibitors of fungal growth in soil up to 93%. A new formulation was developed ‘Navinya’ an eco-friendly plant based formulation, which was tested for its efficiency on host plants at hot spot areas where root rot is a major cause of damage to mulberry plantation. The formulation was effective in inhibiting the fungal pathogen in its spread and inhibits the growth and makes the plant recover, to support the host plant small quantity (8%) growth promoting substances like succinic acid, boric acid is added along with inorganic chemicals (12%) in the formulation. Among the 15 villages participated in the trials all found satisfied with the control of the disease in mulberry plantations.

‘ILAMATHI’- A Phytojuvenoid formulation for Silkworm

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sun, 21 Aug 2011 05:03:00 +0000

Dr. N. Chandramohan, Professor (Retd), Dr. C. A. Mahalingam, Professor and Dr.S. Subramanian, Principal Scientist (at IARI, New Delhi)

The phyto juvenoid- Ilamathi developed by TNAU

Sericulture is a remunerative agro enterprise providing livelihood to millions of people in India. In order to meet our growing demand, the production and productivity of silk has to be improved.

Among various technologies to improve the cocoon productivity, application of juvenile hormone (JH) on silkworm is practiced in several silk producing countries. They tend to keep the Fifth instar silkworm young for a specified period by extending the larval period and increase the silk secretion. It postpones the spinning stage by few hours.

Altosid, R394, Manta and ZR512 are some of the commercial synthetic JH analogues used in countries like Japan and China. Synthetic JH analogues are hitherto not available for use by sericulturists in India. Moreover, the import of the chemical is cost prohibitive. Hence there is a need for identification of cost effective JH formulation for improving silk productivity.

Department of Sericulture, Tamil Nadu Agricultural University, Coimbatore has screened several plant products and short listed fewer plants possessing JH activity, (Phytojuvenoid) against silkworms. Extraction procedures were standardized and a novel botanical formulation was developed. Comparing the growth of silkworm to different phases of moon, the new formulation has been named ‘ILAMATHI’ (young moon) as it keeps the larvae young.

The botanical formulation was found to increase the larval duration, cocoon weight and there by yield of 25.16 percent followed by a collective analysis of research station and OFT showed an increase in cocoon and over control in OFT research station 9.15% cocoon yield was realized by farmers in On Farm Trials.

For treating 100 dfls (40,000 larvae) an additional cost of Rs. 165 was required. An additional yield of 9.48 kg of cocoon was harvested with a monetary return of Rs. 848 for every 100 dfls by was of phytojuvenoid treatment. The net gain is Rs. 684 with a increment cost benefit ratio (ICB) of 1:5:14.

Application Method
Product	TNAU Botanical formulation Ilamathi
Containers size	10ml vial
Time of application	2^nd day of fifth instar larvae
Dose	1ml / litre of water
Concentration	1000 ppm

1. It is applied on mulberry leaves after dissolving 5ml of Illamathi in five liters of water, and feed to 2 day old 5 instar worms.

2. Spray fluid is applied uniformly over the shoots/leaves (in tray rearing) with help of an atomizer (or) garden sprayer and allowed to dry for 30 minutes.

3. Treated leaves are given as two first feeding for the two days old fifth instar.

Caution

1. Don’t postpone the Illamathi application beyond second day of fifth instar.

Merits of ‘ILAMATHI’

1. Application of Illamathi gives an additional cocoon yield of 8kg/100 dfls.

2. It also reduces grasserie disease in silkworm.

3. The application of ‘ILAMATHI’ is safer to silkworm and it will not hinder the growth and development of the larvae. Besides, the formulation also confers resistance to BMNPV infection. Hence application of ‘ILAMATHI’ is a novel technology to boost the silk yield and silk productivity to the farmers of Tamil Nadu.

TNAU starts BSc Sericulture course

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Sun, 07 Aug 2011 17:14:00 +0000

Prof. (Dr.) CA. Mahalingam

Universities, apart from their pedagogical role, as centers for fundamental academic research are vital to agricultural research and development. The sericulture sub sector of Indian agriculture has been a beneficiary to this. Indian sericulture has received kind attention of her agricultural universities, located at those places known for sericulture. University of Agricultural Sciences (UAS) Bangalore and Tamil Nadu Agriculture University (TNAU) are prime examples. Both these institutes have been training manpower for research and extension for long. UAS, Bangalore has been conducting an under graduate program - BSc Sericulture for past few decades. This four year’s graduate degree program has produced a prodigious volume of alumni who decorate coveted positions in the industry. An academic program need not necessarily ensure job placements to its takers. However the quality of the curriculum and its administration are very important in throwing open employment opportunities for students who opt it. Agricultural Universities are hot spots for admission seekers not just because agriculture is a very important discipline. The multiplicity of job opportunities available in public and private sector is an important reason. Recently TNAU has started a BSc sericulture program. We interviewed Prof. (Dr) CA. Mahalingam of Sericulture Department, Tamil Nadu Agricultural University regarding their new initiative.

In the given scenario of declining sericulture and falling prices for sericultural produce, what is the scope of sericulture in Tamil Nadu?

Yes sericulture is declining area-wise. Statistical data show that area has decreased many folds but the production and productivity has increased many folds too. Thanks to the many latest technologies right from Mulberry Nursery to User friendly mountages to Automatic reeling machines to Computer aided weaving designs. In Tamil Nadu after a decline in area due to Papaya mealy-bug during past two years, at present the increase in area is being witnessed. In Karnataka the area is declining but there are lots of reasons for this, one important reason is their mind block in adopting newer technologies.

Prices have not dropped very low during the past five years. There was one low during 2006. But now that due to wrong policy of government (to decrease the import duty of silk) has created some melee. But even after that the prices have stabilized now and it is around Rs. 180 for MV and Rs.240 for BV which is little above Rs. 100 profit for every kg of cocoon. The prices will remain like this atleast for another 4-5 years, keeping in view the growing demand.

The TNAU campus at Coimbatore

Is there a declining trend in employment opportunities for those who are qualified in sericulture? How is the curriculum for the new course designed to meet this challenge?

I take this argument in another form. The opportunities for any graduate, for that matter are not promising. Though all the undergraduates in TNAU passed out during past few years got employed, I can say that they are not employed in either government sector or directly with farming sector. Of course, I agree that efforts have to be made to get sericulture graduates given preference and opportunities in Central Silk Board, State Departments of Sericulture and other sericulture oriented industries.

The syllabus for BSc sericulture is formulated in such a way that 50 % courses are common to agriculture graduates and sericulture graduates, and both of them learn the same basic courses. Only from third year onwards sericulture graduates learn specialized subjects on sericulture. This will empower them to compete along with agriculture graduates in every aspect either for higher education or for job.

Why should a student choose BSc sericulture? - to be a trained farmer? Extension officer? Researcher? Do your program stress on biotechnology?

For the basic degree program, there is no much stress on biotech and molecular biology except for few introductory courses to expose them to the technology. In answering thesecond question, I suggest you to read the following article by Himanshu Pal: Government Jobs after B Sc Sericulture . As I have already said there is no direct employment for any graduate. Any graduate is armed with quality education either to become an entrepreneur (farmer?), a government officer (state or central government or private companies – extension worker?) or scientist (in SAU or CSB or private firms – researcher?).

The Syllubus and Curriculum of the BSc Sericulture course offered by TNAU can be downloaded HERE

Effect of supplementing mulberry leaves with Phyllanthus emblica L. fruit extract on the silkworm Bombyx mori L

gkrajeshrajesh@gmail.com (SILKWORK e-journal) — Wed, 01 Jun 2011 16:21:00 +0000

GK. Rajesh

Scientific Advisor, Council for Nature Conservation and Environmental Protection, CONCEPT, India

Introduction

It is well established fact that ascorbic acid plays an important role in the nutrition of silkworm. It acts as both phago stimulant and nutrient o silkworm (Ito, 1960). Karaksy (1985) showed that ascorbic acid increases silk yield of the mulberry silkworm. Mulberry leaf itself is a rich source of ascorbic acid and contains about 1.8 mg. per gram of leaf (Legay, 1958). However Karaksy (1990) showed that silkworms fed on mulberry leaves enriched with ascorbic acid showed better growth and produced heavier cocoons. Similar observations were made by Madhu Babu (1992)

Goose berry (Phyllanthus emblica L.) is one of the richest sources of ascorbic acid. Barthakur and Arnold (1991) estimated that the berry contain 5889 ppm. Ascorbic acid. Apart from this the berry contain sugars, various minerals, amino acids and vitamins etc all of which play important role in the nutrition of silkworm and silk production (Shyamala and Bhat, 1965; Subbu Rathinam and Sulochana Chetty, 1990; Ito, 1960; and Ito, 1966). In the current experiment mulberry leaves were supplemented with goose berry extract to study its effect on growth and silk production of silkworm.

Material and methods

Mature fruits of Phyllanthus emblica were procured from the department of Horticulture, University of Agricultural Sciences, Bangalore. The fruits were crushed in a stone mortar and the juice extracted through a cheese cloth was collected in amber coloured bottles and corked air tight. From the extract 20%, 40%, 60% and 100% concentrations were prepared using distilled water as diluents. The pH of the various concentrations prepared were 4.2, 2.75, 2.73 and 2.68 respectively. Each concentration served as a treatment. A distilled water control and another control without water were also maintained. Each treatment was replicated thrice. The concentrations were prepared every day fresh and were kept under room temperature. Mulberry leaves were dipped in these solutions shade dried and fed to the larvae twice a day, other feeds being un treated.

The experiment was conducted on 360 fifth instar larvae of C-Nichi race of Bombyx mori reared as recommented by Dandin et al. (2000). Each replication carried twenty larvae. The larvae were fed on mulberry variety M5.

The observations made were: weight of five mature larvae, 5 pupae, shell weight of 5 cocoons and gain in larval weight. The data was statistically analysed.

Results and discussion

The mature larval weight did not differ significantly among the treatments. Gain in larval weight was significantly higher in control (without water), other treatments on par with each other. Pupal weight was significantly higher in the 20% solution treatment, other treatments being on par with each other. Cocoon shell weight did not differ significantly among treatments.

It was observed that the larvae did not relish the leaves treated with higher concentrations. This may be due to the low pH. It is also observed that the larvae fed on higher concentrations had longer larval duration, took more time for pupation and showed pupal deformities and high post cocoon mortality. Some larvae remained inside the cocoon without undergoing pupation. Lower concentrations did not affect pupation.

These observations call for further investigations in the same line using lower concentrations of the emblica fruit extract as a food additive to silkworms, to prolong laraval duration and to mprove silk yield.

References

Barthakur,N.N;1991, Chemcal analysis f the emblica (Phyllanthus emblica L.) and its potential as a food source, Scientia Horticlture. 47: 99-105

Dandin, S.B; Jayant Jayaswal and K. Giridhar ;2000, Handbook of Sericulture Technologies, Central silk Board, p. 195-218

Ito, T; 1960, Effect of sugars on feeding of larva of the silkworm Bombyx mori. L. J. Insect. Physiol. 5: 95-107

Ito, T; 1961, Effect of dietary ascorbic acid on the silkworm Bombyx mori. L; Nature, 192: 951

Ito,T. 1978. Silkworm nutrition: In the Silkworm an Important Laboratory Tool. Tazima,Y.(Ed.) Kodansha Ltd, Tokyo. 121-157.

Karaksy, I.A and Idris, M; 1990, Ascorbic acid enhances the silk yield of the mulberry silkworm. Bombyx mori. L. J. Appl. Ent. 109: 81-86

Karaksy, I.A; 1985, The effect of ascorbic acid on silkworm Bombyx mori. L, Alexandria J. Agric. Res. 30(2):1023-30

Legay, J.M.1958. Recent advances in silkworm nutrition. Ann.Rev.Ent.,3:75-86.

Madhu Babu. Et. Al; 1992, Effect of Ascorbic acid enriched mulberry leaves on rearing of Bombyx mori. L. Indian J. Seric. 31:111-114

Ranganna, S; 1977, Manual of Analysis of Fruits and Vegetable Products. Tata Mc. Graw Hill pub. Co. Ltd. New delhi. Pp.257

Sbburathinam, K.M and Sulochana Chetty, J; 1991, Effect of fortification of mulberry leaves with minerals to silkworm Bombyx mori. L. Indian j. Seric. 30:121-23

Shyamala, M.B and Bhat, J.V; 1965, Mneral assimilation in the silkworm Bombyx mori. L. Indian. J. Exp. Biol. 4:31-34